TY  - JOUR
A1  - Lapa, Constantin
A1  - Kircher, Stefan
A1  - Schirbel, Andreas
A1  - Rosenwald, Andreas
A1  - Kropf, Saskia
A1  - Pelzer, Theo
A1  - Walles, Thorsten
A1  - Buck, Andreas K.
A1  - Weber, Wolfgang A.
A1  - Wester, Hans-Juergen
A1  - Herrmann, Ken
A1  - Lückerath, Katharina
T1  - Targeting CXCR4 with [\(^{68}\)Ga]Pentixafor: a suitable theranostic approach in pleural mesothelioma?
JF  - Oncotarget
N2  - C-X-C motif chemokine receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer. This study investigated the feasibility of CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using [\(^{68}\)Ga]Pentixafor in malignant pleural mesothelioma.

Six patients with pleural mesothelioma underwent [\(^{68}\)Ga]Pentixafor-PET/CT. 2′-[\(^{18}\)F]fluoro-2′-deoxy-D-glucose ([\(^{18}\)F]FDG)-PET/CT (4/6 patients) and immunohistochemistry obtained from biopsy or surgery (all) served as standards of reference. Additionally, 9 surgical mesothelioma samples were available for histological work-up.

Whereas [\(^{18}\)F]FDG-PET depicted active lesions in all patients, [\(^{68}\)Ga]Pentixafor-PET/CT recorded physiologic tracer distribution and none of the 6 patients presented [\(^{68}\)Ga]Pentixafor-positive lesions. This finding paralleled results of immunohistochemistry which also could not identify relevant CXCR4 surface expression in the samples analyzed.

In contrast to past reports, our data suggest widely absence of CXCR4 expression in pleural mesothelioma. Hence, robust cell surface expression should be confirmed prior to targeting this chemokine receptor for diagnosis and/or therapy.
KW  - PET
KW  - CXCR4
KW  - [\(^{68}\)Ga] pentixafor
KW  - pleural mesothelioma
KW  - theranostics
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-169989
VL  - 8
IS  - 57
ER  - 
TY  - JOUR
A1  - Philipp-Abbrederis, Kathrin
A1  - Herrmann, Ken
A1  - Knop, Stefan
A1  - Schottelius, Margret
A1  - Eiber, Matthias
A1  - Lückerath, Katharina
A1  - Pietschmann, Elke
A1  - Habringer, Stefan
A1  - Gerngroß, Carlos
A1  - Franke, Katharina
A1  - Rudelius, Martina
A1  - Schirbel, Andreas
A1  - Lapa, Constantin
A1  - Schwamborn, Kristina
A1  - Steidle, Sabine
A1  - Hartmann, Elena
A1  - Rosenwald, Andreas
A1  - Kropf, Saskia
A1  - Beer, Ambros J
A1  - Peschel, Christian
A1  - Einsele, Hermann
A1  - Buck, Andreas K
A1  - Schwaiger, Markus
A1  - Götze, Katharina
A1  - Wester, Hans-Jürgen
A1  - Keller, Ulrich
T1  - In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma
JF  - EMBO Molecular Medicine
N2  - CXCR4 is a G-protein-coupled receptor that mediates recruitment of blood cells toward its ligand SDF-1. In cancer, high CXCR4 expression is frequently associated with tumor dissemination andpoor prognosis. We evaluated the novel CXCR4 probe [\(^{68}\)Ga]Pentixafor for invivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM by means of positron emission tomography (PET). [\(^{68}\)Ga]Pentixafor PET provided images with excellent specificity and contrast. In 10 of 14 patients with advanced MM [\(^{68}\)Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [\(^{18}\)F]fluorodeoxyglucose PET/CT scans were rated visually positive. Assessment of blood counts and standard CD34\(^{+}\) flow cytometry did not reveal significant blood count changes associated with tracer application. Based on these highly encouraging data on clinical PET imaging of CXCR4 expression in a cohort of MM patients, we conclude that [\(^{68}\)Ga]Pentixafor PET opens a broad field for clinical investigations on CXCR4 expression and for CXCR4-directed therapeutic approaches in MM and other diseases.
KW  - FDG PET/CT
KW  - cells
KW  - CXCR4/SDF-1
KW  - CXCR4
KW  - multiple myeloma
KW  - positron emission tomography
KW  - chemokine receptor
KW  - in vivo imaging
KW  - malignancies
KW  - involvement
KW  - microenvironment
KW  - survival
KW  - cancer
KW  - autologous transplantation
KW  - bone disease
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148738
VL  - 7
IS  - 4
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Weich, Alexander
A1  - Higuchi, Takahiro
A1  - Schmid, Jan S.
A1  - Schirbel, Andreas
A1  - Lassmann, Michael
A1  - Wild, Vanessa
A1  - Rudelius, Martina
A1  - Kudlich, Theodor
A1  - Herrmann, Ken
A1  - Scheurlen, Michael
A1  - Buck, Andreas K.
A1  - Kropf, Saskia
A1  - Wester, Hans-Jürgen
A1  - Lapa, Constantin
T1  - Imaging of Chemokine Receptor 4 Expression in Neuroendocrine Tumors - a Triple Tracer Comparative Approach
JF  - Theranostics
N2  - C-X-C motif chemokine receptor 4 (CXCR4) and somatostatin receptors (SSTR) are overexpressed in gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). In this study, we aimed to elucidate the feasibility of non-invasive CXCR4 positron emission tomography/computed tomography (PET/CT) imaging in GEP-NET patients using [\(^{68}\)Ga]Pentixafor in comparison to \(^{68}\)Ga-DOTA-D-Phe-Tyr3-octreotide ([\(^{68}\)Ga]DOTATOC) and \(^{18}\)F-fluorodeoxyglucose ([\(^{18}\)F]FDG). Twelve patients with histologically proven GEP-NET (3xG1, 4xG2, 5xG3) underwent [\(^{68}\)Ga]DOTATOC, [\(^{18}\)F]FDG, and [\(^{68}\)Ga]Pentixafor PET/CT for staging and planning of the therapeutic management. Scans were analyzed on a patient as well as on a lesion basis and compared to immunohistochemical staining patterns of CXCR4 and somatostatin receptors SSTR2a and SSTR5. [\(^{68}\)Ga]Pentixafor visualized tumor lesions in 6/12 subjects, whereas [\(^{18}\)F]FDG revealed sites of disease in 10/12 and [\(^{68}\)Ga]DOTATOC in 11/12 patients, respectively. Regarding sensitivity, SSTR-directed PET was the superior imaging modality in all G1 and G2 NET. CXCR4-directed PET was negative in all G1 NET. In contrast, 50% of G2 and 80% of G3 patients exhibited [\(^{68}\)Ga]Pentixafor-positive tumor lesions. Whereas CXCR4 seems to play only a limited role in detecting well-differentiated NET, increasing receptor expression could be non-invasively observed with increasing tumor grade. Thus, [\(^{68}\)Ga]Pentixafor PET/CT might serve as non-invasive read-out for evaluating the possibility of CXCR4-directed endoradiotherapy in advanced dedifferentiated SSTR-negative tumors.
KW  - SSTR
KW  - peptide receptor radionuclide therapy
KW  - neuroendocrine tumor
KW  - [\(^{68}\)Ga]Pentixafor
KW  - CXCR4
KW  - chemokine receptor
KW  - PET/CT
KW  - DOTATOC
KW  - PRRT
KW  - Positronen-Emissions-Tomografie
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158008
VL  - 7
IS  - 6
ER  - 
TY  - JOUR
A1  - Bluemel, Christina
A1  - Linke, Fraenze
A1  - Herrmann, Ken
A1  - Simunovic, Iva
A1  - Eiber, Matthias
A1  - Kestler, Christian
A1  - Buck, Andreas K.
A1  - Schirbel, Andreas
A1  - Bley, Thorsten A.
A1  - Wester, Hans-Juergen
A1  - Vergho, Daniel
A1  - Becker, Axel
T1  - Impact of \(^{68}\)Ga-PSMA PET/CT on salvage radiotherapy planning in patients with prostate cancer and persisting PSA values or biochemical relapse after prostatectomy
JF  - EJNMMI Research
N2  - Background

Salvage radiotherapy (SRT) is clinically established in prostate cancer (PC) patients with PSA persistence or biochemical relapse (BCR) after prior radical surgery. PET/CT imaging prior to SRT may be performed to localize disease recurrence. The recently introduced \(^{68}\)Ga-PSMA outperforms other PET tracers for detection of recurrence and is therefore expected also to impact radiation planning.

Forty-five patients with PSA persistence (16 pts) or BCR (29 pts) after prior prostatectomy, scheduled to undergo SRT of the prostate bed, underwent \(^{68}\)Ga-PSMA PET/CT. The median PSA level was 0.67 ng/ml. The impact of \(^{68}\)Ga-PSMA PET/CT on the treatment decision was assessed. Patients with oligometastatic (≤5 lesions) PC underwent radiotherapy (RT), with the extent of the RT area and dose escalation being based on PET positivity.

Results

Suspicious lesions were detected in 24/45 (53.3 %) patients. In 62.5 % of patients, lesions were only detected by 68Ga-PSMA PET. Treatment was changed in 19/45 (42.2 %) patients, e.g., extending SRT to metastases (9/19), administering dose escalation in patients with morphological local recurrence (6/19), or replacing SRT by systemic therapy (2/19). 38/45 (84.4 %) followed the treatment recommendation, with data on clinical follow-up being available in 21 patients treated with SRT. All but one showed biochemical response (mean PSA decline 78 ± 19 %) within a mean follow-up of 8.12 ± 5.23 months.

Conclusions

\(^{68}\)Ga-PSMA PET/CT impacts treatment planning in more than 40 % of patients scheduled to undergo SRT. Future prospective studies are needed to confirm this significant therapeutic impact on patients prior to SRT.
KW  - prostate cancer
KW  - salvage radiotherapy
KW  - PSMA
KW  - PET/CT
KW  - recurrence
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147798
VL  - 6
IS  - 78
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Werner, Rudolf A.
A1  - Bluemel, Christina
A1  - Lueckerath, Katharina
A1  - Muegge, Dirk O.
A1  - Strate, Alexander
A1  - Haenscheid, Heribert
A1  - Schirbel, Andreas
A1  - Allen-Auerbach, Martin S.
A1  - Bundschuh, Ralph A.
A1  - Buck, Andreas K.
A1  - Herrmann, Ken
T1  - Prediction of clinically relevant hyperkalemia in patients treated with peptide receptor radionuclide therapy
JF  - EJNMMI Research
N2  - Background
Peptide receptor radionuclide therapy (PRRT) is applied in patients with advanced neuroendocrine tumors. Co-infused amino acids (AA) should prevent nephrotoxicity. The aims of this study were to correlate the incidence of AA-induced hyperkalemia (HK) (≥5.0 mmol/l) and to identify predictors of AA-induced severe HK (>6.0).

Methods
In 38 patients, standard activity of \(^{177}Lu\)-labelled somatostatin analogs was administered. Pre-therapeutic kidney function was assessed by renal scintigraphy and laboratory tests. For kidney protection, AA was co-infused. Biochemical parameters (potassium, glomerular filtration rate, creatinine, blood urea nitrogen (BUN), sodium, phosphate, chloride, and lactate dehydrogenase (LDH)) were obtained prior to 4 and 24 h after the AA infusion. Incidence of HK (≥5.0) was correlated with pre-therapeutic kidney function and serum parameters. Formulas for the prediction of severe hyperkalemia (>6.0) were computed and prospectively validated.

Results
At 4 h, HK (≥5.0) was present in 94.7% with severe HK (>6.0) in 36.1%. Values normalized after 24 h in 84.2%. Pre-therapeutic kidney function did not correlate with the incidence of severe HK.

Increases in K+ were significantly correlated with decreases in phosphate (r = −0.444, p < 0.005) and increases in BUN (r = 0.313, p = 0.056). A baseline BUN of >28 mg/dl had a sensitivity of 84.6% and a specificity of 60.0% (AUC = 0.75) in predicting severe HK of >6.0 (phosphate, AUC = 0.37).

Computing of five standard serum parameters (potassium, BUN, sodium, phosphate, LDH) resulted in a sensitivity of 88.9% and a specificity of 79.3% for the prediction of severe HK >6.0 (accuracy = 81.6%).

Conclusions
A combination of serum parameters predicted prospectively the occurrence of relevant HK with an accuracy of 81.6% underlining its potential utility for identifying ‘high-risk’ patients prone to PRRT.
KW  - amino acids
KW  - kidney function
KW  - hyperkalemia
KW  - PRRT
KW  - NET
KW  - MAG3
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124963
VL  - 4
IS  - 74
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Beckl, Melanie
A1  - Dierks, Alexander
A1  - Schirbel, Andreas
A1  - Krebs, Markus
A1  - Buck, Andreas
A1  - Kübler, Hubert
A1  - Lapa, Constantin
A1  - Seitz, Anna Katharina
T1  - Detection Rate of \(^{68}\)Ga-PSMA Ligand PET/CT in Patients with Recurrent Prostate Cancer and Androgen Deprivation Therapy
JF  - Biomedicines
N2  - Prostate-specific membrane antigen (PSMA) ligand PET/CT enables the localization of tumor lesions in patients with recurrent prostate cancer, but it is unclear whether androgen deprivation therapy (ADT) influences diagnostic accuracy. The aim of this study was to evaluate the effect of ADT on the detection rate of \(^{68}\)Ga-PSMA ligand PET/CT. Thus, 399 patients with initial radical prostatectomy and 68Ga-PSMA ligand PET/CT during PSA relapse were retrospectively evaluated. Propensity score matching was used to create two balanced groups of 62 subjects who either did or did not receive ADT within six months before imaging. All \(^{68}\)Ga-PSMA ligand PET/CT were evaluated visually and with semiquantitative measures. The detection rate of tumor recurrence was significantly higher in the group with ADT (88.7% vs. 72.6%, p = 0.02) and improved with increasing PSA-levels in both groups. In subjects with pathological PET/CT and ADT, whole-body total lesion PSMA (p < 0.01) and PSMA-derived tumor volume (p < 0.01) were significantly higher than in those without ADT. More PSMA-positive lesions and higher PSMA-derived volumetric parameters in patients with ADT suggest that a better detection rate is related to a (biologically) more advanced disease stage. Due to high detection rates in patients with PSA-levels < 2 ng/mL, the withdrawal of ADT before PSMA ligand PET/CT cannot be recommended.
KW  - 68Ga-PSMA ligand PET/CT
KW  - androgen deprivation therapy
KW  - detection rate
KW  - recurrent prostate cancer
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219301
SN  - 2227-9059
VL  - 8
IS  - 11
ER  - 
TY  - JOUR
A1  - Lückerath, Katharina
A1  - Lapa, Constantin
A1  - Spahmann, Annika
A1  - Jörg, Gerhard
A1  - Samnick, Samuel
A1  - Rosenwald, Andreas
A1  - Einsele, Herrmann
A1  - Knop, Stefan
A1  - Buck, Andreas
T1  - Targeting Paraprotein  Biosynthesis for Non-Invasive Characterization of Myeloma Biology
N2  - Purpose

Multiple myeloma is a hematologic malignancy originating from clonal plasma cells. Despite effective therapies, outcomes are highly variable suggesting marked disease heterogeneity. The role of functional imaging for therapeutic management of myeloma, such as positron emission tomography with 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG-PET), remains to be determined. Although some studies already suggested a prognostic value of 18F-FDG-PET, more specific tracers addressing hallmarks of myeloma biology, e.g. paraprotein biosynthesis, are needed. This study evaluated the amino acid tracers L-methyl-[11C]-methionine (11C-MET) and [18F]-fluoroethyl-L-tyrosine (18F-Fet) for their potential to image myeloma and to characterize tumor heterogeneity.

Experimental Design

To study the utility of 11C-MET, 18F-Fet and 18F-FDG for myeloma imaging, time activity curves were compared in various human myeloma cell lines (INA-6, MM1.S, OPM-2) and correlated to cell-biological characteristics, such as marker gene expression and immunoglobulin levels. Likewise, patient-derived CD138+ plasma cells were characterized regarding uptake and biomedical features.

Results

Using myeloma cell lines and patient-derived CD138+ plasma cells, we found that the relative uptake of 11C-MET exceeds that of 18F-FDG 1.5- to 5-fold and that of 18F-Fet 7- to 20-fold. Importantly, 11C-MET uptake significantly differed between cell types associated with worse prognosis (e.g. t(4;14) in OPM-2 cells) and indolent ones and correlated with intracellular immunoglobulin light chain and cell surface CD138 and CXCR4 levels. Direct comparison of radiotracer uptake in primary samples further validated the superiority of 11C-MET.

Conclusion

These data suggest that 11C-MET might be a versatile biomarker for myeloma superior to routine functional imaging with 18F-FDG regarding diagnosis, risk stratification, prognosis and discrimination of tumor subtypes.
KW  - Myelomas
KW  - Antibodies
KW  - Positron emission tomography
KW  - Myeloma cells
KW  - cell staining
KW  - lesions
KW  - biosynthesis
KW  - bone marrow cells
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111319
ER  - 
TY  - JOUR
A1  - Buder, Kristina
A1  - Lapa, Constantin
A1  - Kreissl, Michael C.
A1  - Schirbel, Andreas
A1  - Herrmann, Ken
A1  - Schnack, Alexander
A1  - Bröcker, Eva-Bettina
A1  - Goebeler, Matthias
A1  - Buck, Andreas K.
A1  - Becker, Jürgen C.
T1  - "Somatostatin receptor  expression in Merkel cell carcinoma as target for molecular imaging"
N2  - Background

Merkel cell carcinoma (MCC) is a rare cutaneous neoplasm with increasing incidence, aggressive behavior and poor prognosis. Somatostatin receptors (SSTR) are expressed in MCC and represent a potential target for both imaging and treatment.

Methods

To non-invasively assess SSTR expression in MCC using PET and the radiotracers [68Ga]DOTA-D-Phe1-Tyr3-octreotide (DOTATOC) or -octreotate (DOTATATE) as surrogate for tumor burden. In 24 patients with histologically proven MCC SSTR-PET was performed and compared to results of computed tomography (CT).

Results

SSTR-PET detected primary and metastatic MCC lesions. On a patient-based analysis, sensitivity of SSTR-PET was 73% for nodal metastases, 100% for bone, and 67% for soft-tissue metastases, respectively. Notably, brain metastases were initially detected by SSTR-PET in 2 patients, whereas liver and lung metastases were diagnosed exclusively by CT. SSTR-PET showed concordance to CT results in 20 out of 24 patients. Four patients (17%) were up-staged due to SSTR-PET and patient management was changed in 3 patients (13%).

Conclusion

SSTR-PET showed high sensitivity for imaging bone, soft tissue and brain metastases, and particularly in combination with CT had a significant impact on clinical stage and patient management.
KW  - Merkel cell carcinoma
KW  - Molecular imaging
KW  - Somatostatin receptor expression
KW  - Positron emission tomography
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110326
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Lapa, Constantin
A1  - Bluemel, Christina
A1  - Lückerath, Katharina
A1  - Schirbel, Andreas
A1  - Strate, Alexander
A1  - Buck, Andreas K.
A1  - Herrmann, Ken
T1  - Influence of the amount of co-infused amino acids on post-therapeutic potassium levels in peptide receptor radionuclide therapy
N2  - Background

Peptide receptor radionuclide therapy (PRRT) is routinely used for advanced or metastasized neuroendocrine tumours (NET). To prevent nephrotoxicity, positively charged amino acids (AA) are co-infused. The aim of this study was to correlate the risk for therapy-related hyperkalaemia with the total amount of AA infused.

Methods

Twenty-two patients undergoing PRRT with standard activities of 177Lu-DOTATATE/-TOC were monitored during two following treatment cycles with co-infusion of 75 and 50 g of AA (L-arginine and L-lysine), respectively. Mean serum levels of potassium and other parameters (glomerular filtration rate [GFR], creatinine, blood urea nitrogen [BUN], phosphate, chloride, lactate dehydrogenase) prior to, 4 h and 24 h after AA infusion were compared.

Results

Self-limiting hyperkalaemia (>5.0 mmol/l) resolving after 24 h occurred in 91% (20/22) of patients in both protocols. Potassium levels, BUN, creatinine, GFR, phosphate, chloride and LDH showed a similar range at 4 h after co-infusion of 75 or 50 g of AA, respectively (p > 0.05). Only GFR and creatinine levels at 24 h varied significantly between the two co-infusion protocols (p < 0.05).

Conclusions

Hyperkalaemia is a frequent side effect of AA infusion in PRRT. Varying the dose of co-infused amino acids did not impact on the incidence and severity of hyperkalaemia.
KW  - NET
KW  - PRRT
KW  - Hyperkalaemia
KW  - Arginine
KW  - Lysine
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110617
ER  - 
TY  - JOUR
A1  - Kosmala, Aleksander
A1  - Serfling, Sebastian E.
A1  - Dreher, Niklas
A1  - Lindner, Thomas
A1  - Schirbel, Andreas
A1  - Lapa, Constantin
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Weich, Alexander
A1  - Werner, Rudolf A.
T1  - Associations between normal organs and tumor burden in patients imaged with fibroblast activation protein inhibitor-directed positron emission tomography
JF  - Cancers
N2  - (1) Background: We aimed to quantitatively investigate [\(^{68}\)Ga]Ga-FAPI-04 uptake in normal organs and to assess a relationship with the extent of FAPI-avid tumor burden. (2) Methods: In this single-center retrospective analysis, thirty-four patients with solid cancers underwent a total of 40 [\(^{68}\)Ga]Ga-FAPI-04 PET/CT scans. Mean standardized uptake values (SUV\(_{mean}\)) for normal organs were established by placing volumes of interest (VOIs) in the heart, liver, spleen, pancreas, kidneys, and bone marrow. Total tumor burden was determined by manual segmentation of tumor lesions with increased uptake. For tumor burden, quantitative assessment included maximum SUV (SUV\(_{max}\)), tumor volume (TV), and fractional tumor activity (FTA = TV × SUV\(_{mean}\)). Associations between uptake in normal organs and tumor burden were investigated by applying Spearman's rank correlation coefficient. (3) Results: Median SUV\(_{mean}\) values were 2.15 in the pancreas (range, 1.05–9.91), 1.42 in the right (range, 0.57–3.06) and 1.41 in the left kidney (range, 0.73–2.97), 1.2 in the heart (range, 0.46–2.59), 0.86 in the spleen (range, 0.55–1.58), 0.65 in the liver (range, 0.31–2.11), and 0.57 in the bone marrow (range, 0.26–0.94). We observed a trend towards significance for uptake in the myocardium and tumor-derived SUV\(_{max}\) (ρ = 0.29, p = 0.07) and TV (ρ = −0.30, p = 0.06). No significant correlation was achieved for any of the other organs: SUV\(_{max}\) (ρ ≤ 0.1, p ≥ 0.42), TV (ρ ≤ 0.11, p ≥ 0.43), and FTA (ρ ≤ 0.14, p ≥ 0.38). In a sub-analysis exclusively investigating patients with high tumor burden, significant correlations of myocardial uptake with tumor SUV\(_{max}\) (ρ = 0.44; p = 0.03) and tumor-derived FTA with liver uptake (ρ = 0.47; p = 0.02) were recorded. (4) Conclusions: In this proof-of-concept study, quantification of [\(^{68}\)Ga]Ga-FAPI-04 PET showed no significant correlation between normal organs and tumor burden, except for a trend in the myocardium. Those preliminary findings may trigger future studies to determine possible implications for treatment with radioactive FAP-targeted drugs, as higher tumor load or uptake may not lead to decreased doses in the majority of normal organs.
KW  - PET
KW  - [\(^{68}\)Ga]Ga-FAPI
KW  - theranostics
KW  - radioligand therapy
KW  - fibroblast activation protein
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-275154
SN  - 2072-6694
VL  - 14
IS  - 11
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Herrmann, Ken
A1  - Schirbel, Andreas
A1  - Hänscheid, Heribert
A1  - Lückerath, Katharina
A1  - Schottelius, Margret
A1  - Kircher, Malte
A1  - Werner, Rudolf A.
A1  - Schreder, Martin
A1  - Samnick, Samuel
A1  - Kropf, Saskia
A1  - Knop, Stefan
A1  - Buck, Andreas K.
A1  - Einsele, Hermann
A1  - Wester, Hans-Juergen
A1  - Kortüm, K. Martin
T1  - CXCR4-directed endoradiotherapy induces high response rates in extramedullary relapsed multiple myeloma
JF  - Theranostics
N2  - C-X-C-motif chemokine receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer. We have recently reported promising first-in-man experience with CXCR4-directed endoradiotherapy (ERT) in multiple myeloma (MM).

Eight heavily pretreated MM patients underwent a total of 10 ERT cycles (7 patients with 1 cycle and a single patient with 3 cycles). ERT was administered in combination with chemotherapy and autologous stem cell support. End points were occurrence and timing of adverse events, progression-free and overall survival.

ERT was overall well tolerated without any unexpected acute adverse events or changes in vital signs. With absorbed tumor doses >30-70 Gy in intra- or extramedullary lesions, significant anti-myeloma activity was observed with 1 patient achieving complete remission and 5/8 partial remission. Directly after ERT major infectious complications were seen in one patient who died from sepsis 22 days after ERT, another patient with high tumor burden experienced lethal tumor lysis syndrome. Median progression-free survival was 54 days (range, 13-175), median overall survival was 223 days (range, 13-313). During follow-up (6 patients available), one patient died from infectious complications, 2/8 from disease progression, the remaining 3/8 patients are still alive.

CXCR4-directed ERT was well-tolerated and exerted anti-myeloma activity even at very advanced stage MM with presence of extramedullary disease. Further assessment of this novel treatment option is highly warranted.
KW  - medicine
KW  - multiple myeloma
KW  - PET
KW  - CXCR4
KW  - theranostics
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172095
VL  - 7
IS  - 6
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Schreder, Martin
A1  - Schirbel, Andreas
A1  - Samnick, Samuel
A1  - Kortüm, Klaus Martin
A1  - Herrmann, Ken
A1  - Kropf, Saskia
A1  - Einsele, Herrmann
A1  - Buck, Andreas K.
A1  - Wester, Hans-Jürgen
A1  - Knop, Stefan
A1  - Lückerath, Katharina
T1  - [\(^{68}\)Ga]Pentixafor-PET/CT for imaging of chemokine receptor CXCR4 expression in multiple myeloma - comparison to [\(^{18}\)F]FDG and laboratory values
JF  - Theranostics
N2  - Chemokine (C-X-C motif) receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer including multiple myeloma (MM). Proof-of-concept of CXCR4-directed radionuclide therapy in MM has recently been reported. This study assessed the diagnostic performance of the CXCR4-directed radiotracer [\(^{68}\)Ga]Pentixafor in MM and a potential role for stratifying patients to CXCR4-directed therapies.

Thirty-five patients with MM underwent [\(^{68}\)Ga]Pentixafor-PET/CT for evaluation of eligibility for endoradiotherapy. In 19/35 cases, [\(^{18}\)F]FDG-PET/CT for correlation was available. Scans were compared on a patient and on a lesion basis. Tracer uptake was correlated with standard clinical parameters of disease activity.

[\(^{68}\)Ga]Pentixafor-PET detected CXCR4-positive disease in 23/35 subjects (66%). CXCR4-positivity at PET was independent from myeloma subtypes, cytogenetics or any serological parameters and turned out as a negative prognostic factor. In the 19 patients in whom a comparison to [\(^{18}\)F]FDG was available, [\(^{68}\)Ga]Pentixafor-PET detected more lesions in 4/19 (21%) subjects, [\(^{18}\)F]FDG proved superior in 7/19 (37%). In the remaining 8/19 (42%) patients, both tracers detected an equal number of lesions. [\(^{18}\)F]FDG-PET positivity correlated with [\(^{68}\)Ga]Pentixafor-PET positivity (p=0.018).

[\(^{68}\)Ga]Pentixafor-PET provides further evidence that CXCR4 expression frequently occurs in advanced multiple myeloma, representing a negative prognostic factor and a potential target for myeloma specific treatment. However, selecting patients for CXCR4 directed therapies and prognostic stratification seem to be more relevant clinical applications for this novel imaging modality, rather than diagnostic imaging of myeloma.
KW  - medicine
KW  - multiple myeloma
KW  - FDG
KW  - molecular imaging
KW  - CXCR4
KW  - PET
KW  - radionuclide therapy
KW  - theranostics
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172106
VL  - 7
IS  - 1
ER  - 
TY  - JOUR
A1  - Zhou, Xiang
A1  - Dierks, Alexander
A1  - Kertels, Olivia
A1  - Kircher, Malte
A1  - Schirbel, Andreas
A1  - Samnick, Samuel
A1  - Buck, Andreas K.
A1  - Knorz, Sebastian
A1  - Böckle, David
A1  - Scheller, Lukas
A1  - Messerschmidt, Janin
A1  - Barakat, Mohammad
A1  - Kortüm, K. Martin
A1  - Rasche, Leo
A1  - Einsele, Hermann
A1  - Lapa, Constantin
T1  - 18F-FDG, 11C-Methionine, and 68Ga-Pentixafor PET/CT in patients with smoldering multiple myeloma: imaging pattern and clinical features
JF  - Cancers
N2  - This study aimed to explore the correlation between imaging patterns and clinical features in patients with smoldering multiple myeloma (SMM) who simultaneously underwent 18F-FDG, 11C-Methionine, and 68Ga-Pentixafor positron emission tomography/computed tomography (PET/CT). We retrieved and analyzed clinical characteristics and PET imaging data of 10 patients with SMM. We found a significant correlation between bone marrow (BM) plasma cell (PC) infiltration and mean standardized uptake values (SUV\(_{mean}\)) of lumbar vertebrae L2-L4 on 11C-Methionine PET/CT scans (r = 0.676, p = 0.031) and 68Ga-Pentixafor PET/CT scans (r = 0.839, p = 0.002). However, there was no significant correlation between BM involvement and SUV\(_{mean}\) of lumbar vertebrae L2-L4 on 18F-FDG PET/CT scans (r = 0.558, p = 0.093). Similarly, mean target-to-background ratios (TBR\(_{mean}\)) of lumbar vertebrae L2-L4 also correlated with bone marrow plasma cell (BMPC) infiltration in 11C-Methionine PET/CT (r = 0.789, p = 0.007) and 68Ga-Pentixafor PET/CT (r = 0.724, p = 0.018) PET/CT. In contrast, we did not observe a significant correlation between BMPC infiltration rate and TBR\(_{mean}\) in 18F-FDG PET/CT (r = 0.355, p = 0.313). Additionally, on 11C-Methionine PET/CT scans, we found a significant correlation between BMPC infiltration and TBR\(_{max}\) of lumbar vertebrae L2-L4 (r = 0.642, p = 0.045). In conclusion, 11C-Methionine and 68Ga-Pentixafor PET/CT demonstrate higher sensitivity than 18F-FDG PET/CT in detecting BM involvement in SMM.
KW  - 18F-FDG PET/CT
KW  - 11C-Methionine PET/CT
KW  - 68Ga-Pentixafor PET/CT
KW  - smoldering myeloma
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211240
SN  - 2072-6694
VL  - 12
IS  - 8
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Heinrich, Marieke
A1  - Seitz, Anna Katharina
A1  - Brumberg, Joachim
A1  - Sokolakis, Ioannis
A1  - Kalogirou, Charis
A1  - Schirbel, Andreas
A1  - Kübler, Hubert
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Krebs, Markus
T1  - Metabolic Tumour Volume from PSMA PET/CT Scans of Prostate Cancer Patients during Chemotherapy — Do Different Software Solutions Deliver Comparable Results?
JF  - Journal of Clinical Medicine
N2  - (1) Background: Prostate-specific membrane antigen (PSMA)-derived tumour volume (PSMA-TV) and total lesion PSMA (TL-PSMA) from PSMA PET/CT scans are promising biomarkers for assessing treatment response in prostate cancer (PCa). Currently, it is unclear whether different software tools for assessing PSMA-TV and TL-PSMA produce comparable results. (2) Methods: \(^{68}\)Ga-PSMA PET/CT scans from n = 21 patients with castration-resistant PCa (CRPC) receiving chemotherapy were identified from our single-centre database. PSMA-TV and TL-PSMA were calculated with Syngo.via (Siemens) as well as the freely available Beth Israel plugin for FIJI (Fiji Is Just ImageJ) before and after chemotherapy. While statistical comparability was illustrated and quantified via Bland-Altman diagrams, the clinical agreement was estimated by matching PSMA-TV, TL-PSMA and relative changes of both variables during chemotherapy with changes in serum PSA (ΔPSA) and PERCIST (Positron Emission Response Criteria in Solid Tumors). (3) Results: Comparing absolute PSMA-TV and TL-PSMA as well as Bland–Altman plotting revealed a good statistical comparability of both software algorithms. For clinical agreement, classifying therapy response did not differ between PSMA-TV and TL-PSMA for both software solutions and showed highly positive correlations with BR. (4) Conclusions: due to the high levels of statistical and clinical agreement in our CRPC patient cohort undergoing taxane chemotherapy, comparing PSMA-TV and TL-PSMA determined by Syngo.via and FIJI appears feasible.
KW  - prostate-specific membrane antigen (PSMA)
KW  - metabolic tumour volume (MTV)
KW  - total lesion PSMA
KW  - biomarker
KW  - software
KW  - comparability
KW  - agreement
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-205893
SN  - 2077-0383
VL  - 9
IS  - 5
ER  - 
TY  - JOUR
A1  - Hänscheid, Heribert
A1  - Hartrampf, Philipp E.
A1  - Schirbel, Andreas
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
T1  - Intraindividual comparison of [\(^{177}\)Lu]Lu-DOTA-EB-TATE and [\(^{177}\)Lu]Lu-DOTA-TOC
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Purpose
The radiolabelled somatostatin analogue [\(^{177}\)Lu]Lu-DOTA-EB-TATE binds to albumin via Evans blue, thereby increasing the residence time in the blood and potentially allowing more therapeutic agent to be absorbed into the target tissue during peptide receptor radionuclide therapy. It was tested in selected patients whether the substance is superior to [\(^{177}\)Lu]Lu-DOTA-TOC.
Methods
Activity kinetics in organs and tumours after [\(^{177}\)Lu]Lu-DOTA-EB-TATE and [\(^{177}\)Lu]Lu-DOTA-TOC were compared intraindividually in five patients with progressive somatostatin receptor-positive disease scheduled for radionuclide therapy.
Resuluts
In comparison to [\(^{177}\)Lu]Lu-DOTA-TOC, tumour doses per administered activity were higher for [\(^{177}\)Lu]Lu-DOTA-EB-TATE in 4 of 5 patients (median ratio: 1.7; range: 0.9 to 3.9), kidney doses (median ratio: 3.2; range: 1.6 to 9.8) as well as spleen doses (median ratio: 4.7; range 1.2 to 6.2) in all patients, and liver doses in 3 of 4 evaluable patients (median ratio: 4.0; range: 0.7 to 4.9). The tumour to critical organs absorbed dose ratios were higher after [\(^{177}\)Lu]Lu-DOTA-TOC in 4 of 5 patients.
Conclusions
Prior to a treatment with [\(^{177}\)Lu]Lu-DOTA-EB-TATE, it should be assessed individually whether the compound is superior to established substances.
KW  - intraindividual comparison
KW  - DOTA-EB-TATE
KW  - somatostatin receptor
KW  - evans blue
KW  - biokinetics
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265470
SN  - 1619-7089
VL  - 48
IS  - 8
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Kircher, Stefan
A1  - Higuchi, Takahiro
A1  - Kircher, Malte
A1  - Schirbel, Andreas
A1  - Wester, Hans-Jürgen
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
T1  - CXCR4-directed imaging in solid tumors
JF  - Frontiers in Oncology
N2  - Despite histological evidence in various solid tumor entities, available experience with CXCR4-directed diagnostics and endoradiotherapy mainly focuses on hematologic diseases. With the goal of expanding the application of CXCR4 theranostics to solid tumors, we aimed to elucidate the feasibility of CXCR4-targeted imaging in a variety of such neoplasms.
Methods: Nineteen patients with newly diagnosed, treatment-naïve solid tumors including pancreatic adenocarcinoma or neuroendocrine tumor, cholangiocarcinoma, hepatocellular carcinoma, renal cell carcinoma, ovarian cancer, and prostate cancer underwent [\(^{68}\)Ga]Pentixafor PET/CT. CXCR4-mediated uptake was assessed both visually and semi-quantitatively by evaluation of maximum standardized uptake values (SUV\(_{max}\)) of both primary tumors and metastases. With physiologic liver uptake as reference, tumor-to-background ratios (TBR) were calculated. [\(^{68}\)Ga]Pentixafor findings were further compared to immunohistochemistry and [\(^{18}\)F]FDG PET/CT.
Results: On [\(^{68}\)Ga]Pentixafor PET/CT, 10/19 (52.6%) primary tumors were visually detectable with a median SUVmax of 5.4 (range, 1.7–16.0) and a median TBR of 2.6 (range, 0.8–7.4), respectively. The highest level of radiotracer uptake was identified in a patient with cholangiocarcinoma (SUVmax, 16.0; TBR, 7.4). The relatively low uptake on [\(^{68}\)Ga]Pentixafor was also noted in metastases, exhibiting a median SUVmax of 4.5 (range, 2.3–8.8; TBR, 1.7; range, 1.0–4.1). A good correlation between uptake on [\(^{68}\)Ga]Pentixafor and histological derived CXCR4 expression was noted (R = 0.62, P < 0.05). In the 3 patients in whom [\(^{18}\)F]FDG PET/CT was available, [\(^{68}\)Ga]Pentixafor exhibited lower uptake in all lesions.
Conclusions: In this cohort of newly diagnosed, treatment-naïve patients with solid malignancies, CXCR4 expression as detected by [\(^{68}\)Ga]Pentixafor-PET/CT and immunohistochemistry was rather moderate. Thus, CXCR4-directed imaging may not play a major role in the management of solid tumors in the majority of patients.
KW  - CXCR4
KW  - [68Ga]Pentixafor
KW  - theranostics
KW  - solid tumors
KW  - chemokine receptor
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195678
SN  - 2234-943X
VL  - 9
IS  - 770
ER  - 
TY  - JOUR
A1  - Breun, Maria
A1  - Monoranu, Camelia M.
A1  - Kessler, Almuth F.
A1  - Matthies, Cordula
A1  - Löhr, Mario
A1  - Hagemann, Carsten
A1  - Schirbel, Andreas
A1  - Rowe, Steven P.
A1  - Pomper, Martin G.
A1  - Buck, Andreas K.
A1  - Wester, Hans-Jürgen
A1  - Ernestus, Ralf-Ingo
A1  - Lapa, Constantin
T1  - [\(^{68}\)Ga]-Pentixafor PET/CT for CXCR4-mediated imaging of vestibular schwannomas
JF  - Frontiers in Oncology
N2  - We have recently demonstrated CXCR4 overexpression in vestibular schwannomas (VS). This study investigated the feasibility of CXCR4-directed positron emission tomography/computed tomography (PET/CT) imaging of VS using the radiolabeled chemokine ligand [\(^{68}\)Ga]Pentixafor.

Methods: 4 patients with 6 primarily diagnosed or pre-treated/observed VS were enrolled. All subjects underwent [\(^{68}\)Ga]Pentixafor PET/CT prior to surgical resection. Images were analyzed visually and semi-quantitatively for CXCR4 expression including calculation of tumor-to-background ratios (TBR). Immunohistochemistry served as standard of reference in three patients.

Results: [\(^{68}\)Ga]Pentixafor PET/CT was visually positive in all cases. SUV\(_{mean}\) and SUV\(_{max}\) were 3.0 ± 0.3 and 3.8 ± 0.4 and TBR\(_{mean}\) and TBR\(_{max}\) were 4.0 ± 1.4 and 5.0 ± 1.7, respectively. Histological analysis confirmed CXCR4 expression in tumors.

Conclusion: Non-invasive imaging of CXCR4 expression using [\(^{68}\)Ga]Pentixafor PET/CT of VS is feasible and could prove useful for in vivo assessment of CXCR4 expression.
KW  - vestibular schwannoma
KW  - CXCR4
KW  - PET/CT
KW  - molecular imaging
KW  - Pentixafor
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201863
VL  - 9
IS  - 503
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Kircher, Malte
A1  - Hänscheid, Heribert
A1  - Schirbel, Andreas
A1  - Grigoleit, Götz Ulrich
A1  - Klinker, Erdwine
A1  - Böck, Markus
A1  - Samnick, Samuel
A1  - Pelzer, Theo
A1  - Buck, Andreas K
T1  - Peptide receptor radionuclide therapy as a new tool in treatment-refractory sarcoidosis - initial experience in two patients
JF  - Theranostics
N2  - Sarcoidosis is a multisystem granulomatous disorder of unknown etiology that can involve virtually all organ systems. Whereas most patients present without symptoms, progressive and disabling organ failure can occur in up to 10% of subjects. Somatostatin receptor (SSTR)-directed peptide receptor radionuclide therapy (PRRT) has recently received market authorization for treatment of SSTR-positive neuroendocrine tumors.

Methods: 
We describe the first case series comprising two patients with refractory multi-organ involvement of sarcoidosis who received 4 cycles of PRRT.

Results: 
PRRT was well-tolerated without any acute adverse effects. No relevant toxicities could be recorded during follow-up. Therapy resulted in partial response accompanied by a pronounced reduction in pain (patient #1) and stable disease regarding morphology as well as disease activity (patient #2), respectively.

Conclusion: 
Peptide receptor radionuclide therapy in sarcoidosis is feasible and might be a new valuable tool in patients with otherwise treatment-refractory disease. Given the long experience with and good tolerability of PRRT, further evaluation of this new treatment option for otherwise treatment-refractory sarcoidosis in larger patient cohorts is warranted.
KW  - peptide receptor
KW  - PRRT
KW  - sarcoidosis
KW  - somatostatin receptors
KW  - radionuclide therapy
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158983
VL  - 8
IS  - 3
ER  - 
TY  - JOUR
A1  - Aster, Hans-Christoph
A1  - Romanos, Marcel
A1  - Walitza, Susanne
A1  - Gerlach, Manfred
A1  - Mühlberger, Andreas
A1  - Rizzo, Albert
A1  - Andreatta, Marta
A1  - Hasenauer, Natalie
A1  - Hartrampf, Philipp E.
A1  - Nerlich, Kai
A1  - Reiners, Christoph
A1  - Lorenz, Reinhard
A1  - Buck, Andreas K.
A1  - Deserno, Lorenz
T1  - Responsivity of the striatal dopamine system to methylphenidate — A within-subject I-123-β-CIT-SPECT study in male children and adolescents with attention-deficit/hyperactivity disorder
JF  - Frontiers in Psychiatry
N2  - Background:
Methylphenidate (MPH) is the first-line pharmacological treatment of attention-deficit/hyperactivity disorder (ADHD). MPH binds to the dopamine (DA) transporter (DAT), which has high density in the striatum. Assessments of the striatal dopamine transporter by single positron emission computed tomography (SPECT) in childhood and adolescent patients are rare but can provide insight on how the effects of MPH affect DAT availability. The aim of our within-subject study was to investigate the effect of MPH on DAT availability and how responsivity to MPH in DAT availability is linked to clinical symptoms and cognitive functioning.


Methods
Thirteen adolescent male patients (9–16 years) with a diagnosis of ADHD according to the DSM-IV and long-term stimulant medication (for at least 6 months) with MPH were assessed twice within 7 days using SPECT after application of I-123-β-CIT to examine DAT binding potential (DAT BP). SPECT measures took place in an on- and off-MPH status balanced for order across participants. A virtual reality continuous performance test was performed at each time point. Further clinical symptoms were assessed for baseline off-MPH.


Results
On-MPH status was associated with a highly significant change (−29.9%) of striatal DAT BP as compared to off-MPH (t = −4.12, p = 0.002). A more pronounced change in striatal DAT BP was associated with higher off-MPH attentional and externalizing symptom ratings (Pearson r = 0.68, p = 0.01). Striatal DAT BP off-MPH, but not on-MPH, was associated with higher symptom ratings (Pearson r = 0.56, p = 0.04).


Conclusion
Our findings corroborate previous reports from mainly adult samples that MPH changes striatal DAT BP availability and suggest higher off-MPH DAT BP, likely reflecting low baseline DA levels, as a marker of symptom severity.
KW  - methylphenidate
KW  - attention deficit/hyperactivity disorder (ADHD)
KW  - striatum
KW  - single photon emission computed tomography (SPECT)
KW  - responsivity
KW  - caudate nucleus
KW  - dopamine transporter (DAT)
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270862
SN  - 1664-0640
VL  - 13
ER  - 
TY  - JOUR
A1  - Heinze, Britta
A1  - Schirbel, Andreas
A1  - Nannen, Lukas
A1  - Michelmann, David
A1  - Hartrampf, Philipp E.
A1  - Bluemel, Christina
A1  - Schneider, Magdalena
A1  - Herrmann, Ken
A1  - Haenscheid, Heribert
A1  - Fassnacht, Martin
A1  - Buck, Andreas K.
A1  - Hahner, Stefanie
T1  - Novel CYP11B-ligand [\(^{123/131}\)I]IMAZA as promising theranostic tool for adrenocortical tumors: comprehensive preclinical characterization and first clinical experience
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Purpose
Adrenal tumors represent a diagnostic and therapeutic challenge. Promising results have been obtained through targeting the cytochrome P450 enzymes CYP11B1 and CYP11B2 for molecular imaging, and [\(^{123/131}\)I]iodometomidate ([\(^{123/131}\)I]IMTO) has even been successfully introduced as a theranostic agent. As this radiopharmaceutical shows rapid metabolic inactivation, we aimed at developing new improved tracers.
Methods
Several IMTO derivatives were newly designed by replacing the unstable methyl ester by different carboxylic esters or amides. The inhibition of aldosterone and cortisol synthesis was tested in different adrenocortical cell lines. The corresponding radiolabeled compounds were assessed regarding their stability, in vitro cell uptake, in vivo biodistribution in mice, and their binding specificity to cryosections of human adrenocortical and non-adrenocortical tissue. Furthermore, a first investigation was performed in patients with known metastatic adrenal cancer using both [\(^{123}\)I]IMTO and the most promising compound (R)-1-[1-(4-[\(^{123/}\)I]iodophenyl)ethyl]-1H-imidazole-5-carboxylic acid azetidinylamide ([\(^{123}\)I]IMAZA) for scintigraphy. Subsequently, a first endoradiotherapy with [\(^{131}\)I]IMAZA in one of these patients was performed.
Results
We identified three analogues to IMTO with high-affinity binding to the target enzymes and comparable or higher metabolic stability and very high and specific accumulation in adrenocortical cells in vitro and in vivo. Labeled IMAZA exhibited superior pharmacokinetic and imaging properties compared to IMTO in mice and 3 patients, too. An endoradiotherapy with [\(^{131}\)I]IMAZA induced a 21-month progression-free interval in a patient with rapidly progressing ACC prior this therapy.
Conclusion
We developed the new radiopharmaceutical [\(^{123/131}\)I]IMAZA with superior properties compared to the reference compound IMTO and promising first experiences in humans.
KW  - CYP11B enzymes
KW  - adrenal incidentaloma
KW  - adrenocortical carcinoma
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265606
SN  - 1619-7089
VL  - 49
IS  - 1
ER  - 
TY  - JOUR
A1  - Lenschow, Christina
A1  - Wennmann, Andreas
A1  - Hendricks, Anne
A1  - Germer, Christoph-Thomas
A1  - Fassnacht, Martin
A1  - Buck, Andreas
A1  - Werner, Rudolf A.
A1  - Plassmeier, Lars
A1  - Schlegel, Nicolas
T1  - Questionable value of [\(^{99m}\)Tc]-sestamibi scintigraphy in patients with pHPT and negative ultrasound
JF  - Langenbeck’s Archives of Surgery
N2  - Purpose
A successful focused surgical approach in primary hyperparathyroidism (pHPT) relies on accurate preoperative localization of the parathyroid adenoma (PA). Most often, ultrasound is followed by [\(^{99m}\)Tc]-sestamibi scintigraphy, but the value of this approach is disputed. Here, we evaluated the diagnostic approach in patients with surgically treated pHPT in our center with the aim to further refine preoperative diagnostic procedures.

Methods
A single-center retrospective analysis of patients with pHPT from 01/2005 to 08/2021 was carried out followed by evaluation of the preoperative imaging modalities to localize PA. The localization of the PA had to be confirmed intraoperatively by the fresh frozen section and significant dropping of the intraoperative parathyroid hormone (PTH) levels.

Results
From 658 patients diagnosed with pHPT, 30 patients were excluded from the analysis because of surgery for recurrent or persistent disease. Median age of patients was 58.0 (13–93) years and 71% were female. Neck ultrasound was carried out in 91.7% and localized a PA in 76.6%. In 23.4% (135/576) of the patients, preoperative neck ultrasound did not detect a PA. In this group, [\(^{99m}\)Tc]-sestamibi correctly identified PA in only 25.4% of patients. In contrast, in the same cohort, the use of [\(^{11}\)C]-methionine or [\(^{11}\)C]-choline PET resulted in the correct identification of PA in 79.4% of patients (OR 13.23; 95% CI 5.24–33.56).

Conclusion
[\(^{11}\)C]-Methionine or [\(^{11}\)C]-choline PET/CT are superior second-line imaging methods to select patients for a focused surgical approach when previous ultrasound failed to identify PA.
KW  - primary hyperparathyroidism
KW  - parathyroid adenoma
KW  - [99mTc]-Sestamibi scan
KW  - [11C]-Methionine
KW  - [11C]-Choline PET/CT
KW  - focused surgical approach
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-323926
VL  - 407
IS  - 8
ER  - 
TY  - JOUR
A1  - Serfling, Sebastian E.
A1  - Lapa, Constantin
A1  - Dreher, Niklas
A1  - Hartrampf, Philipp E.
A1  - Rowe, Steven P.
A1  - Higuchi, Takahiro
A1  - Schirbel, Andreas
A1  - Weich, Alexander
A1  - Hahner, Stefanie
A1  - Fassnacht, Martin
A1  - Buck, Andreas K.
A1  - Werner, Rudolf A.
T1  - Impact of tumor burden on normal organ distribution in patients imaged with CXCR4-targeted [\(^{68}\)Ga]Ga-PentixaFor PET/CT
JF  - Molecular Imaging and Biology
N2  - Background
CXCR4-directed positron emission tomography/computed tomography (PET/CT) has been used as a diagnostic tool in patients with solid tumors. We aimed to determine a potential correlation between tumor burden and radiotracer accumulation in normal organs.

Methods
Ninety patients with histologically proven solid cancers underwent CXCR4-targeted [\(^{68}\)Ga]Ga-PentixaFor PET/CT. Volumes of interest (VOIs) were placed in normal organs (heart, liver, spleen, bone marrow, and kidneys) and tumor lesions. Mean standardized uptake values (SUV\(_{mean}\)) for normal organs were determined. For CXCR4-positive tumor burden, maximum SUV (SUV\(_{max}\)), tumor volume (TV), and fractional tumor activity (FTA, defined as SUV\(_{mean}\) x TV), were calculated. We used a Spearman's rank correlation coefficient (ρ) to derive correlative indices between normal organ uptake and tumor burden.

Results
Median SUV\(_{mean}\) in unaffected organs was 5.2 for the spleen (range, 2.44 – 10.55), 3.27 for the kidneys (range, 1.52 – 17.4), followed by bone marrow (1.76, range, 0.84 – 3.98), heart (1.66, range, 0.88 – 2.89), and liver (1.28, range, 0.73 – 2.45). No significant correlation between SUV\(_{max}\) in tumor lesions (ρ ≤ 0.189, P ≥ 0.07), TV (ρ ≥ -0.204, P ≥ 0.06) or FTA (ρ ≥ -0.142, P ≥ 0.18) with the investigated organs was found.

Conclusions
In patients with solid tumors imaged with [\(^{68}\)Ga]Ga-PentixaFor PET/CT, no relevant tumor sink effect was noted. This observation may be of relevance for therapies with radioactive and non-radioactive CXCR4-directed drugs, as with increasing tumor burden, the dose to normal organs may remain unchanged.
KW  - CXCR4
KW  - C-X-C motif chemokine receptor 4
KW  - PET
KW  - [68Ga]PentixaFor
KW  - [177Lu]/[90Y]PentixaTher
KW  - theranostics
KW  - endoradiotherapy
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324622
VL  - 24
IS  - 4
ER  - 
TY  - JOUR
A1  - Lambertini, Alessandro
A1  - Hartrampf, Philipp E.
A1  - Higuchi, Takahiro
A1  - Serfling, Sebastian E.
A1  - Meybohm, Patrick
A1  - Schirbel, Andreas
A1  - Buck, Andreas K.
A1  - Werner, Rudolf A.
T1  - CXCR4-targeted molecular imaging after severe SARS-Cov-2 infection
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - No abstract available.
KW  - CXCR4-targeting
KW  - SARS-CoV-2
KW  - COVID-19
KW  - molecular imaging
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324619
VL  - 50
IS  - 1
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Seitz, Anna Katharina
A1  - Weinzierl, Franz-Xaver
A1  - Serfling, Sebastian E.
A1  - Schirbel, Andreas
A1  - Rowe, Steven P.
A1  - Kübler, Hubert
A1  - Buck, Andreas K.
A1  - Werner, Rudolf A.
T1  - Baseline clinical characteristics predict overall survival in patients undergoing radioligand therapy with [\(^{177}\)Lu]Lu-PSMA I&T during long-term follow-up
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Background
Radioligand therapy (RLT) with \(^{177}\)Lu-labeled prostate-specific membrane antigen (PSMA) ligands is associated with prolonged overall survival (OS) in patients with advanced, metastatic castration-resistant prostate cancer (mCRPC). A substantial number of patients, however, are prone to treatment failure. We aimed to determine clinical baseline characteristics to predict OS in patients receiving [\(^{177}\)Lu]Lu-PSMA I&T RLT in a long-term follow-up.

Materials and methods
Ninety-two mCRPC patients treated with [\(^{177}\)Lu]Lu-PSMA I&T with a follow-up of at least 18 months were retrospectively identified. Multivariable Cox regression analyses were performed for various baseline characteristics, including laboratory values, Gleason score, age, prior therapies, and time interval between initial diagnosis and first treatment cycle (interval\(_{Diagnosis-RLT}\), per 12 months). Cutoff values for significant predictors were determined using receiver operating characteristic (ROC) analysis. ROC-derived thresholds were then applied to Kaplan–Meier analyses.

Results
Baseline C-reactive protein (CRP; hazard ratio [HR], 1.10, 95% CI 1.02–1.18; P = 0.01), lactate dehydrogenase (LDH; HR, 1.07, 95% CI 1.01–1.11; P = 0.01), aspartate aminotransferase (AST; HR, 1.16, 95% CI 1.06–1.26; P = 0.001), and interval\(_{Diagnosis-RLT}\) (HR, 0.95, 95% CI 0.91–0.99; P = 0.02) were identified as independent prognostic factors for OS. The following respective ROC-based thresholds were determined: CRP, 0.98 mg/dl (area under the curve [AUC], 0.80); LDH, 276.5 U/l (AUC, 0.83); AST, 26.95 U/l (AUC, 0.73); and interval\(_{Diagnosis-RLT}\), 43.5 months (AUC, 0.68; P < 0.01, respectively). Respective Kaplan–Meier analyses demonstrated a significantly longer median OS of patients with lower CRP, lower LDH, and lower AST, as well as prolonged interval\(_{Diagnosis-RLT}\) (P ≤ 0.01, respectively).

Conclusion
In mCRPC patients treated with [\(^{177}\)Lu]Lu-PSMA I&T, baseline CRP, LDH, AST, and time interval until RLT initiation (thereby reflecting a possible indicator for tumor aggressiveness) are independently associated with survival. Our findings are in line with previous findings on [\(^{177}\)Lu]Lu-PSMA-617, and we believe that these clinical baseline characteristics may support the nuclear medicine specialist to identify long-term survivors.
KW  - PSMA
KW  - prostate cancer
KW  - [177Lu]Lu-PSMA I&T
KW  - radioligand therapy
KW  - overall survival
KW  - prediction
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324573
VL  - 49
IS  - 12
ER  - 
TY  - JOUR
A1  - Buck, Andreas K.
A1  - Serfling, Sebastian E.
A1  - Lindner, Thomas
A1  - Hänscheid, Heribert
A1  - Schirbel, Andreas
A1  - Hahner, Stefanie
A1  - Fassnacht, Martin
A1  - Einsele, Hermann
A1  - Werner, Rudolf A.
T1  - CXCR4-targeted theranostics in oncology
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - A growing body of literature reports on the upregulation of C-X-C motif chemokine receptor 4 (CXCR4) in a variety of cancer entities, rendering this receptor as suitable target for molecular imaging and endoradiotherapy in a theranostic setting. For instance, the CXCR4-targeting positron emission tomography (PET) agent [\(^{68}\)Ga]PentixaFor has been proven useful for a comprehensive assessment of the current status quo of solid tumors, including adrenocortical carcinoma or small-cell lung cancer. In addition, [\(^{68}\)Ga]PentixaFor has also provided an excellent readout for hematological malignancies, such as multiple myeloma, marginal zone lymphoma, or mantle cell lymphoma. PET-based quantification of the CXCR4 capacities in vivo allows for selecting candidates that would be suitable for treatment using the theranostic equivalent [\(^{177}\)Lu]/[\(^{90}\)Y]PentixaTher. This CXCR4-directed theranostic concept has been used as a conditioning regimen prior to hematopoietic stem cell transplantation and to achieve sufficient anti-lymphoma/-tumor activity in particular for malignant tissues that are highly sensitive to radiation, such as the hematological system. Increasing the safety margin, pretherapeutic dosimetry is routinely performed to determine the optimal activity to enhance therapeutic efficacy and to reduce off-target adverse events. The present review will provide an overview of current applications for CXCR4-directed molecular imaging and will introduce the CXCR4-targeted theranostic concept for advanced hematological malignancies.
KW  - CXCR4
KW  - theranostics
KW  - C-X-C motif chemokine receptor 4
KW  - [68Ga]PentixaFor
KW  - [177Lu]PentixaTher
KW  - [90Y]PentixaTher
KW  - endoradiotherapy
KW  - adrenocortical carcinoma
KW  - multiple myeloma
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324545
VL  - 49
IS  - 12
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Weinzierl, Franz-Xaver
A1  - Buck, Andreas K.
A1  - Rowe, Steven P.
A1  - Higuchi, Takahiro
A1  - Seitz, Anna Katharina
A1  - Kübler, Hubert
A1  - Schirbel, Andreas
A1  - Essler, Markus
A1  - Bundschuh, Ralph A.
A1  - Werner, Rudolf A.
T1  - Matched-pair analysis of [\(^{177}\)Lu]Lu-PSMA I&T and [\(^{177}\)Lu]Lu-PSMA-617 in patients with metastatic castration-resistant prostate cancer
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Background
Labelled with lutetium-177, the urea-based small molecules PSMA I&T and PSMA-617 are the two agents most frequently used for radioligand therapy (RLT) in patients with advanced metastatic castration-resistant and prostate-specific membrane antigen (PSMA) expressing prostate cancer (mCRPC). In this matched-pair analysis, we aimed to compare the toxicity and efficacy of both agents for PSMA-directed RLT.

Materials and methods
A total of 110 mCRPC patients from two centres were accrued, 55 individuals treated with [\(^{177}\)Lu]Lu-PSMA I&T, and a matched cohort of 55 patients treated with [\(^{177}\)Lu]Lu-PSMA-617. Matching criteria included age at the first cycle, Gleason score, prostate-specific antigen (PSA) values, and previous taxane-based chemotherapy. Using common terminology criteria for adverse events (CTCAE v. 5.0), toxicity profiles were investigated (including bone marrow and renal toxicity). Overall survival (OS) between both groups was compared.

Results
Toxicity assessment revealed grade III anaemia in a single patient (1.8%) for [\(^{177}\)Lu]Lu-PSMA I&T and five (9.1%) for [\(^{177}\)Lu]Lu-PSMA-617. In addition, one (1.9%) grade III thrombopenia for [\(^{177}\)Lu]Lu-PSMA-617 was recorded. Apart from that, no other grade III/IV toxicities were present. A median OS of 12 months for patients treated with [\(^{177}\)Lu]Lu-PSMA I&T did not differ significantly when compared to patients treated with [\(^{177}\)Lu]Lu-PSMA-617 (median OS, 13 months; P = 0.89).

Conclusion
In this matched-pair analysis of patients receiving one of the two agents most frequently applied for PSMA RLT, the rate of clinically relevant toxicities was low for both compounds. In addition, no relevant differences for OS were observed.
KW  - PSMA I&T
KW  - PSMA-617
KW  - prostate-specific membrane antigen
KW  - prostate cancer
KW  - radioligand therapy
KW  - matched pair
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324581
VL  - 49
IS  - 9
ER  - 
TY  - JOUR
A1  - Linz, Christian
A1  - Brands, Roman C.
A1  - Kertels, Olivia
A1  - Dierks, Alexander
A1  - Brumberg, Joachim
A1  - Gerhard-Hartmann, Elena
A1  - Hartmann, Stefan
A1  - Schirbel, Andreas
A1  - Serfling, Sebastian
A1  - Zhi, Yingjun
A1  - Buck, Andreas K.
A1  - Kübler, Alexander
A1  - Hohm, Julian
A1  - Lapa, Constantin
A1  - Kircher, Malte
T1  - Targeting fibroblast activation protein in newly diagnosed squamous cell carcinoma of the oral cavity – initial experience and comparison to [\(^{18}\)F]FDG PET/CT and MRI
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Purpose
While [\(^{18}\)F]-fluorodeoxyglucose ([\(^{18}\)F]FDG) is the standard for positron emission tomography/computed tomography (PET/CT) imaging of oral squamous cell carcinoma (OSCC), diagnostic specificity is hampered by uptake in inflammatory cells such as neutrophils or macrophages. Recently, molecular imaging probes targeting fibroblast activation protein α (FAP), which is overexpressed in a variety of cancer-associated fibroblasts, have become available and might constitute a feasible alternative to FDG PET/CT.

Methods
Ten consecutive, treatment-naïve patients (8 males, 2 females; mean age, 62 ± 9 years) with biopsy-proven OSCC underwent both whole-body [\(^{18}\)F]FDG and [\(^{68}\)Ga]FAPI-04 (FAP-directed) PET/CT for primary staging prior to tumor resection and cervical lymph node dissection. Detection of the primary tumor, as well as the presence and number of lymph node and distant metastases was analysed. Intensity of tracer accumulation was assessed by means of maximum (SUV\(_{max}\)) and peak (SUV\(_{peak}\) standardized uptake values. Histological work-up including immunohistochemical staining for FAP served as standard of reference.

Results
[\(^{18}\)F]FDG and FAP-directed PET/CT detected all primary tumors with a SUVmax of 25.5 ± 13.2 (FDG) and 20.5 ± 6.4 (FAP-directed) and a SUVpeak of 16.1 ± 10.3 ([\(^{18}\)F]FDG) and 13.8 ± 3.9 (FAP-directed), respectively. Regarding cervical lymph node metastases, FAP-directed PET/CT demonstrated comparable sensitivity (81.3% vs. 87.5%; P = 0.32) and specificity (93.3% vs. 81.3%; P = 0.16) to [\(^{18}\)F]FDG PET/CT. FAP expression on the cell surface of cancer-associated fibroblasts in both primary lesions as well as lymph nodes metastases was confirmed in all samples.

Conclusion
FAP-directed PET/CT in OSCC seems feasible. Future research to investigate its potential to improve patient staging is highly warranted.
KW  - molecular imaging
KW  - fibroblast activation protein
KW  - head and neck cancer
KW  - PET
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-307246
SN  - 1619-7070
SN  - 1619-7089
VL  - 48
IS  - 12
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Küsters, Sebastian
A1  - Al-Momani, Ehab
A1  - Marotta, Giorgio
A1  - Cosgrove, Kelly P.
A1  - van Dyck, Christopher H.
A1  - Herrmann, Ken
A1  - Homola, György A.
A1  - Pezzoli, Gianni
A1  - Buck, Andreas K.
A1  - Volkmann, Jens
A1  - Samnick, Samuel
A1  - Isaias, Ioannis U.
T1  - Cholinergic activity and levodopa-induced dyskinesia: a multitracer molecular imaging study
JF  - Annals of Clinical and Translational Neurology
N2  - Objective: To investigate the association between levodopa‐induced dyskinesias and striatal cholinergic activity in patients with Parkinson's disease.
Methods: This study included 13 Parkinson's disease patients with peak‐of‐dose levodopa‐induced dyskinesias, 12 nondyskinetic patients, and 12 healthy controls. Participants underwent 5‐[\(^{123}\)I]iodo‐3‐[2(S)‐2‐azetidinylmethoxy]pyridine single‐photon emission computed tomography, a marker of nicotinic acetylcholine receptors, [\(^{123}\)I]N‐ω‐fluoropropyl‐2β‐carbomethoxy‐3β‐(4‐iodophenyl)nortropane single‐photon emission computed tomography, to measure dopamine reuptake transporter density and 2‐[\(^{18}\)F]fluoro‐2‐deoxyglucose positron emission tomography to assess regional cerebral metabolic activity. Striatal binding potentials, uptake values at basal ganglia structures, and correlations with clinical variables were analyzed.
Results: Density of nicotinic acetylcholine receptors in the caudate nucleus of dyskinetic subjects was similar to that of healthy controls and significantly higher to that of nondyskinetic patients, in particular, contralaterally to the clinically most affected side.
Interpretation: Our findings support the hypothesis that the expression of dyskinesia may be related to cholinergic neuronal excitability in a dopaminergic‐depleted striatum. Cholinergic signaling would play a role in maintaining striatal dopaminergic responsiveness, possibly defining disease phenotype and progression.
KW  - levodopa-induced dyskinesia
KW  - cholinergic activity
KW  - Parkinson’s disease
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170406
VL  - 4
IS  - 9
ER  - 
TY  - JOUR
A1  - Werner, Rudolf
A1  - Schmid, Jan-Stefan
A1  - Higuchi, Takahiro
A1  - Javadi, Mehrbod S.
A1  - Rowe, Steven P.
A1  - Märkl, Bruno
A1  - Aulmann, Christoph
A1  - Fassnacht, Martin
A1  - Kroiß, Matthias
A1  - Reiners, Christoph
A1  - Buck, Andreas
A1  - Kreissl, Michael
A1  - Lapa, Constantin
T1  - Predictive value of \(^{18}\)F-FDG PET in patients with advanced medullary thyroid carcinoma treated with vandetanib
JF  - Journal of Nuclear Medicine
N2  - Introduction: Therapeutic options in advanced medullary thyroid carcinoma (MTC) have markedly improved since the introduction of tyrosine kinase inhibitors (TKI). We
aimed to assess the role of metabolic imaging using 2-deoxy-2-(\(^{18}\)F)fluoro-D-glucose (\(^{18}\)F-FDG) positron emission tomography/computed tomography (PET/CT) shortly before and 3 months after initiation of TKI treatment. 
Methods: Eighteen patients with advanced and progressive MTC scheduled for vandetanib treatment underwent baseline \(^{18}\)F-FDG PET/CT prior to and 3 months after TKI treatment initiation. During follow-up, CT scans were performed every 3 months and analyzed according to Response Evaluation Criteria In Solid Tumors (RECIST). The predictive value for estimating progression-free (PFS) and overall survival (OS) was examined by investigating \(^{18}\)F-FDG mean/maximum standardized uptake values (SUVmean/max) of the metabolically most active lesion as well as by analyzing clinical parameters (tumor marker doubling times {calcitonin, carcinoembryonic antigen (CEA)}, prior therapies, RET (rearranged during transfection) mutational status, and disease type).
Results: Within a median follow-up of 5.2 years, 9 patients experienced disease progression after a median time interval of 2.1y whereas the remainder had ongoing disease control (n=5 partial response and n=4 stable disease). Eight of the 9 patients with progressive disease died from MTC after a median of 3.5y after TKI initiation.
Pre-therapeutic SUVmean >4.0 predicted a significantly shorter PFS (PFS: 1.9y vs. 5.2y; p=0.04). Furthermore, sustained high 18F-FDG uptake at 3 months with a SUVmean>2.8 tended to portend an unfavorable prognosis with a PFS of 1.9y (vs. 3.5y; p=0.3). Prolonged CEA doubling times were significantly correlated with longer PFS (r=0.7) and OS (r=0.76, p<0.01, respectively). None of the other clinical parameters had prognostic significance. 
Conclusions: Pre-therapeutic \(^{18}\)F-FDG PET/CT holds prognostic information in patients with advanced MTC scheduled for treatment with the TKI vandetanib. Low tumor metabolism of SUVmean < 4.0 prior to treatment predicts longer progression-free survival.
KW  - positron emission tomography
KW  - Medullärer Schilddrüsenkrebs
KW  - Positronen-Emissions-Tomografie
KW  - medullary thyroid carcinoma
KW  - tyrosine kinase inhibitor
KW  - vandetanib
KW  - 2- deoxy-2-(18F)fluoro-D-glucose
KW  - 18F-FDG
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161256
SN  - 0161-5505
N1  - This research was originally published in JNM. Rudolf A. Werner, Jan-Stefan Schmid, Takahiro Higuchi, Mehrbod S. Javadi, Steven P. Rowe, Bruno Märkl, Christoph Aulmann, Martin Fassnacht, Matthias Kroiss, Christoph Reiners, Andreas K. Buck, Michael C. Kreissl, Constantin Lapa. Predictive value of 18F-FDG PET in patients with advanced medullary thyroid carcinoma treated with vandetanib. J Nucl Med. May 1, 2018;vol. 59 no. 5: 756-761. © SNMMI.
ER  - 
TY  - JOUR
A1  - Werner, Rudolf
A1  - Solnes, Lilja
A1  - Javadi, Mehrbod
A1  - Weich, Alexander
A1  - Gorin, Michael
A1  - Pienta, Kenneth
A1  - Higuchi, Takahiro
A1  - Buck, Andreas
A1  - Pomper, Martin
A1  - Rowe, Steven
A1  - Lapa, Constantin
T1  - SSTR-RADS Version 1.0 as a Reporting System for SSTR-PET Imaging and Selection of Potential PRRT Candidates: A Proposed Standardization Framework
JF  - Journal of Nuclear Medicine
N2  - Reliable standards and criteria for somatostatin receptor (SSTR) positron emission tomography (PET) are still lacking. We herein propose a structured reporting system on a 5-point scale for SSTR-PET imaging, titled SSTR-RADS version 1.0, which might serve as a standardized assessment for both diagnosis and treatment planning in neuroendocrine tumors (NET). SSTR-RADS could guide the imaging specialist in interpreting SSTR-PET scans, facilitate communication with the referring clinician so that appropriate work-up for equivocal findings is pursued, and serve as a reliable tool for patient selection for planned Peptide Receptor Radionuclide Therapy.
KW  - Radionuclide Therapy
KW  - Standardisierung
KW  - Positronen-Emissions-Tomografie
KW  - 68Ga-DOTATATE/-TOC
KW  - Gastrointestinal
KW  - Neuroendocrine
KW  - Neuroendocrine Tumor
KW  - Oncology
KW  - GI
KW  - PET
KW  - PET/CT
KW  - PRRT
KW  - RADS
KW  - SSTR
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161298
SN  - 0161-5505
N1  - This  research  was  originally  published  in  JNM. Rudolf  A. Werner, Lilja  B. Solnes, Mehrbod Som  Javadi, Alexander  Weich, Michael A. Gorin, Kenneth J. Pienta, Takahiro  Higuchi, Andreas K. Buck, Martin G. Pomper, Steven P. Rowe, Constantin Lapa. SSTR-RADS Version 1.0 as   a Reporting System for SSTR-PET Imaging and Selection of Potential PRRT Candidates: A Proposed Standardization Framework. J. Nucl. Med. July 1, 2018, vol. 59, no. 7, 1085-1091. © SNMMI
ER  - 
TY  - CHAP
A1  - Werner, Rudolf A.
A1  - Marcus, Charles
A1  - Sheikhbahaei, Sara
A1  - Higuchi, Takahiro
A1  - Solnes, Lilja B.
A1  - Rowe, Steven P.
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
T1  - Diagnostic Accuracy of Visual Assessment of an Initial DaT-Scan in Comparison to a Fully Automatic Semiquantitative Method
T2  - Journal of Nuclear Medicine
N2  - No abstract available.
KW  - Parkinson-Krankheit
KW  - SPECT
KW  - Parkinson
KW  - Parkinson Disease
KW  - DaTscan
KW  - Ioflupane
KW  - molecular imaging
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162208
UR  - http://jnm.snmjournals.org/content/59/supplement_1/626.abstract
SN  - 0161-5505
N1  - This research was originally published in JNM. Rudolf A. Werner, Charles Marcus, Sara Sheikhbahaei, Takahiro Higuchi, Lilja B. Solnes, Steven P. Rowe, Andreas K. Buck, Constantin Lapa, Mehrbod S. Javadi. Diagnostic Accuracy of Visual Assessment of an Initial DaT-Scan in Comparison to a Fully Automatic Semiquantitative Method. J Nucl Med. May 1, 2018; vol. 59 no. supplement 1:626. © SNMMI.
VL  - 59
IS  - Supplement No. 1
SP  - 626
ER  - 
TY  - CHAP
A1  - Werner, Rudolf A.
A1  - Marcus, Charles
A1  - Sheikhbahaei, Sara
A1  - Higuchi, Takahiro
A1  - Solnes, Lilja B.
A1  - Rowe, Steven P.
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
T1  - The Impact of Ageing on Dopamine Transporter Imaging
T2  - Journal of Nuclear Medicine
N2  - No abstract available.
KW  - Parkinson-Krankheit
KW  - Parkinson
KW  - Parkinson Disease
KW  - DaTscan
KW  - Ioflupane
KW  - SPECT
KW  - molecular imaging
KW  - ageing
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-162213
UR  - http://jnm.snmjournals.org/content/59/supplement_1/1646.abstract
SN  - 0161-5505
N1  - This research was originally published in JNM. Rudolf A. Werner, Charles Marcus, Sara Sheikhbahaei, Takahiro Higuchi, Lilja B. Solnes, Steven P. Rowe, Andreas K. Buck, Constantin Lapa, Mehrbod S. Javadi. The Impact of Ageing on Dopamine Transporter Imaging. J Nucl Med. May 1, 2018; vol. 59 no. supplement 1:1646. © SNMMI.
VL  - 59
IS  - Supplement No 1
SP  - 1646
ER  - 
TY  - INPR
A1  - Werner, Rudolf A.
A1  - Ilhan, Harun
A1  - Lehner, Sebastian
A1  - Papp, László
A1  - Zsótér, Norbert
A1  - Schatka, Imke
A1  - Muegge, Dirk O.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Bartenstein, Peter
A1  - Bengel, Frank
A1  - Essler, Markus
A1  - Lapa, Constantin
A1  - Bundschuh, Ralph A.
T1  - Pre-therapy Somatostatin-Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy
T2  - Molecular Imaging and Biology
N2  - Purpose: Early identification of aggressive disease could improve decision-support in pancreatic neuroendocrine tumor (pNET) patients prior to peptide receptor radionuclide therapy (PRRT). The prognostic value of intratumoral textural features (TF) determined by baseline somatostatin receptor (SSTR)-PET before PRRT was analyzed.
Procedures: 31 patients with G1/G2 pNET were enrolled (G2, n=23/31). Prior to PRRT with [\(^{177}\)Lu]DOTATATE (mean, 3.6 cycles), baseline SSTR-PET/CT was performed. By segmentation of 162 (median per patient, 5) metastases, intratumoral TF were computed. The impact of conventional PET parameters  (SUV\(_{mean/max}\)), imaging-based TF as well as clinical parameters (Ki67, CgA) for prediction of both progression-free (PFS) and overall survival (OS) after PRRT was evaluated.
Results: Within a median follow-up of 3.7y, tumor progression was detected in 21 patients (median, 1.5y) and 13/31 deceased (median, 1.9y). In ROC analysis, the TF Entropy, reflecting derangement on a voxel-by-voxel level, demonstrated predictive capability for OS (cutoff=6.7, AUC=0.71, p=0.02). Of note, increasing Entropy could predict a longer survival (>6.7, OS=2.5y, 17/31), whereas less voxel-based derangement portended inferior outcome (<6.7, OS=1.9y, 14/31). These findings were supported in a G2 subanalysis (>6.9, OS=2.8y, 9/23 vs. <6.9, OS=1.9y, 14/23). Kaplan-Meier analysis revealed a significant distinction between high- and low-risk groups using Entropy (n=31, p<0.05). For those patients below the ROC-derived threshold, the relative risk of death after PRRT was 2.73 (n=31, p=0.04). Ki67 was negatively associated with PFS (p=0.002); however, SUVmean/max failed in prognostication (n.s.).
Conclusions: In contrast to conventional PET parameters, assessment of intratumoral heterogeneity demonstrated superior prognostic performance in pNET patients undergoing PRRT. This novel PET-based strategy of outcome prediction prior to PRRT might be useful for patient risk stratification.
KW  - Pancreas
KW  - Positronen-Emissions-Tomografie
KW  - PET
KW  - neuroendocrine tumor
KW  - tumor heterogeneity
KW  - [68Ga]
KW  - [177Lu]-DOTATATE/-DOTATOC
KW  - PET/CT
KW  - SSTR
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164624
UR  - https://link.springer.com/article/10.1007/s11307-018-1252-5
SN  - 1536-1632
N1  - This is a post-peer-review, pre-copyedit version of an article published in Molecular Imaging and Biology. The final authenticated version is available online at: http://dx.doi.org/s11307-018-1252-5
N1  - Die finale Version dieses Artikels steht unter https://doi.org/10.1007/s11307-018-1252-5 bzw. http://nbn-resolving.org/urn:nbn:de:bvb:20-opus-167168 open access zur Verfügung.
ER  - 
TY  - CHAP
A1  - Werner, Rudolf
A1  - Higuchi, Takahiro
A1  - Muegge, Dirk
A1  - Javadi, Mehrbod S.
A1  - Märkl, Bruno
A1  - Aulmann, Christoph
A1  - Buck, Andreas K.
A1  - Fassnacht, Martin
A1  - Lapa, Constantin
A1  - Kreissl, Michael C.
T1  - Predictive value of FDG-PET in patients with advanced medullary thyroid cancer undergoing vandetanib treatment
T2  - Journal of Nuclear Medicine
N2  - Introduction: The prognosis of medullary thyroid carcinoma (MTC) is poor using common chemotherapeutic approaches. However, during the last years encouraging results of recently introduced tyrosine kinase inhibitors (TKI) such as vandetanib have been published. In this study we aimed to correlate the results of \(^{18}\)F-fluorodeoxyglucose ([\(^{18}\)F]FDG) positron emission tomography (PET) imaging with treatment outcome.

Methods: Eighteen patients after thyroidectomy with recurrent/advanced MTC lesions receiving vandetanib (300 mg orally/day) could be analysed. A baseline \(^{18}\)F-FDG PET prior to and a follow-up \(^{18}\)F-FDG PET 3 months after TKI initiation were performed. During follow-up, tumor progression was assessed every 3 months including computed tomography according to RECIST. Progression-free survival (PFS) was correlated with the maximum standardized uptake value of \(^{18}\)F-FDG in lymph nodes (SUV(LN)max) or visceral metastases (SUV(MTS)max) as well as with clinical parameters using ROC analysis.

Results: Within median 3.6 years of follow-up, 9 patients showed disease progression at median 8.5 months after TKI initiation. An elevated glucose consumption assessed by baseline \(^{18}\)F-FDG PET (SUV(LN)max > 7.25) could predict a shorter PFS (2 y) with an accuracy of 76.5% (SUV(LN)max <7.25, 4.3 y; p=0.03). Accordingly, preserved tumor metabolism in the follow-up PET (SUV(MTS)max >2.7) also demonstrated an unfavorable prognosis (accuracy, 85.7%). On the other hand, none of the clinical parameters reached significance in response prediction.

Conclusions: In patients with advanced and progressive MTC, tumors with higher metabolic activity at baseline are more aggressive and more prone to progression as reflected by a shorter PFS; they should be monitored more closely. Preserved glucose consumption 3 months after treatment initiation was also related to poorer prognosis.
KW  - 18F-FDG
KW  - vandetanib
KW  - TKI
KW  - PET
KW  - positron emission tomography
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161147
UR  - http://jnm.snmjournals.org/content/58/supplement_1/169
SN  - 0161-5505
N1  - This  research  was  originally  published  in  JNM. 
Rudolf  A.  Werner,  Takahiro  Higuchi, Dirk O. Muegge, Mehrbod S. Javadi, B. Märkl, C. Aulmann, Andreas K. Buck, Martin Fassnacht,  Constantin  Lapa, Michael  C.  Kreissl. 
Predictive  value  of  FDG-PET  in patients with advanced medullary thyroid cancer undergoing vandetanib treatment. J Nucl Med. May 1, 2017; vol. 58 no. supplement 1:169. © SNMMI.
VL  - 58
IS  - no. supplement 1
ER  - 
TY  - CHAP
A1  - Werner, Rudolf
A1  - Lapa, Constantin
A1  - Buck, Andreas
A1  - Lassmann, Michael
A1  - Hänscheid, Heribert
T1  - Less is sometimes more – Accurate Dose Mapping after Endoradiotherapy with  \(^{177}\)Lu-DOTATATE/-TOC by One-Single Measurement after 96 h
T2  - Journal of Nuclear Medicine
N2  - No abstract available.
KW  - Neuroendocrine Tumor
KW  - theranostics
KW  - 177Lu-DOTATATE
KW  - 177Lu-DOTATOC
KW  - PRRT
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161168
UR  - http://jnm.snmjournals.org/content/58/supplement_1/247.abstract
SN  - 0161-5505
N1  - This research was originally published in JNM. Werner R.A., Lapa C., Buck A.K., Lassmann M., Hänscheid H.Less is sometimes more – Accurate Dose Mapping after Endoradiotherapy with 177Lu-DOTATATE/-TOC by One-Single Measurement after 96 h. J Nucl Med May 1, 2017 vol. 58 no. supplement 1:247. © SNMMI
VL  - 58
IS  - No. Supplement 1
PB  - Society of Nuclear Medicine and Molecular Imaging
ER  - 
TY  - INPR
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
A1  - Bundschuh, Lena
A1  - Fanti, Stefano
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Weich, A.
A1  - Pienta, Kenneth J.
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Herrmann, Ken
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
T1  - Novel Structured Reporting Systems for Theranostic Radiotracers
T2  - Journal of Nuclear Medicine
N2  - Standardized reporting is more and more routinely implemented in clinical practice and such structured reports have a major impact on a large variety of medical fields, e.g. laboratory medicine, pathology, and, recently, radiology. Notably, the field of nuclear medicine is constantly evolving, as novel radiotracers for numerous clinical applications are developed. Thus, framework systems for standardized reporting in this field may a) increase clinical acceptance of new radiotracers, b) allow for inter- and intra-center comparisons for quality assurance, and c) may be used in (global) multi-center studies to ensure comparable results and enable efficient data abstraction. In the last two years, several standardized framework systems for positron emission tomography (PET) radiotracers with potential theranostic applications have been proposed. These include systems for prostate-specific membrane antigen (PSMA)-targeted PET agents for the diagnosis and treatment of prostate cancer (PCa) and somatostatin receptor (SSTR)-targeted PET agents for the diagnosis and treatment of neuroendocrine neoplasias. In the present review, those standardized framework systems for PSMA- and SSTR-targeted PET will be briefly introduced followed by an overview of their advantages and limitations. In addition, potential applications will be defined, approaches to validate such concepts will be proposed, and future perspectives will be discussed.
KW  - standardized reporting
KW  - Positronen-Emissions-Tomografie
KW  - prostate cancer
KW  - neuroendocrine neoplasia
KW  - 68Ga-DOTATATE
KW  - 68Ga-DOTATOC
KW  - 68Ga-DOTANOC
KW  - somatostatin receptor
KW  - SSTR
KW  - prostate-specific membrane antigen
KW  - PSMA
KW  - RADS
KW  - PSMA-RADS
KW  - SSTR-RADS
KW  - MI-RADS
KW  - PROMISE
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-174629
SN  - 0161-5505
N1  - This research was originally published in JNM. Authors: Rudolf A. Werner, Ralph A. Bundschuh, Lena Bundschuh, Stefano Fanti, Mehrbod S. Javadi, Takahiro Higuchi, A. Weich, Kenneth J. Pienta, Andreas K. Buck, Martin G. Pomper, Michael A. Gorin, Ken Herrmann, Constantin Lapa, Steven P. Rowe. Novel Structured Reporting Systems for Theranostic Radiotracers. J Nucl Med May 1, 2019 vol. 60 no. 5 577-584 © SNMMI.
ER  - 
TY  - JOUR
A1  - Lückerath, Katharina
A1  - Lapa, Constantin
A1  - Albert, Christa
A1  - Herrmann, Ken
A1  - Jörg, Gerhard
A1  - Samnick, Samuel
A1  - Einsele, Herrmann
A1  - Knop, Stefan
A1  - Buck, Andreas K.
T1  - \(^{11}\)C-Methionine-PET: a novel and sensitive tool for monitoring of early response to treatment in multiple myeloma
JF  - Oncotarget
N2  - Multiple myeloma (MM) remains an essentially incurable hematologic malignancy. However, new treatment modalities and novel drugs have been introduced and thus additional tools for therapy monitoring are increasingly needed. Therefore, we evaluated the radiotracers \(^{11}\)C-Methionine (paraprotein-biosynthesis) and \(^{18}\)F-FDG (glucose-utilization) for monitoring response to anti-myeloma-therapy and outcome prediction. Influence of proteasome-inhibition on radiotracer-uptake of different MM cell-lines and patient-derived CD138\(^{+}\) plasma cells was analyzed and related to tumor-biology. Mice xenotransplanted with MM. 1S tumors underwent MET- and FDG-\(\mu\)PET. Tumor-to-background ratios before and after 24 h, 8 and 15 days treatment with bortezomib were correlated to survival. Treatment reduced both MET and FDG uptake; changes in tracer-retention correlated with a switch from high to low CD138-expression. In xenotransplanted mice, MET-uptake significantly decreased by 30-79% as early as 24 h after bortezomib injection. No significant differences were detected thus early with FDG. This finding was confirmed in patient-derived MM cells. Importantly, early reduction of MET-but not FDG-uptake correlated with improved survival and reduced tumor burden in mice. Our results suggest that MET is superior to FDG in very early assessment of response to anti-myeloma-therapy. Early changes in MET-uptake have predictive potential regarding response and survival. MET-PET holds promise to individualize therapies in MM in future.
KW  - positron emission tomography
KW  - imaging techniques
KW  - experience
KW  - \(^{11}\)C-Methionine-PET
KW  - treatment response
KW  - molecular imaging
KW  - multiple myeloma
KW  - management
KW  - \(^{18}\)F-FDG PET/CT
KW  - bone disease
KW  - stem-cell transplantation
KW  - esophagogastric junction
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148688
VL  - 6
IS  - 10
ER  - 
TY  - INPR
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
A1  - Bundschuh, Lena
A1  - Javadi, Mehrbod S.
A1  - Leal, Jeffrey P.
A1  - Higuchi, Takahiro
A1  - Pienta, Kenneth J.
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
T1  - Interobserver Agreement for the Standardized Reporting System PSMA-RADS 1.0 on \(^{18}\)F-DCFPyL PET/CT Imaging
T2  - Journal of Nuclear Medicine
N2  - Objectives: Recently, the standardized reporting and data system for prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging studies, termed PSMA-RADS version 1.0, was introduced. We aimed to determine the interobserver agreement for applying PSMA-RADS to imaging interpretation of 18F-DCFPyL PET examinations in a prospective setting mimicking the typical clinical work-flow at a prostate cancer referral center. 
Methods: Four readers (two experienced readers (ER, > 3 years of PSMA-targeted PET interpretation experience) and two inexperienced readers (IR, < 1 year of experience)), who had all read the initial publication on PSMA-RADS 1.0, assessed 50 18F-DCFPyL PET/computed tomography (CT) studies independently. Per scan, a maximum of 5 target lesions were selected by the observers and a PSMA-RADS score for every target lesion was recorded. No specific pre-existing conditions were placed on the selection of the target lesions, although PSMA-RADS 1.0 suggests that readers focus on the most highly avid or largest lesions. An overall scan impression based on PSMA-RADS was indicated and interobserver agreement rates on a target lesion-based, on an organ-based, and on an overall PSMA-RADS score-based level were computed.
Results: The number of target lesions identified by each observer were as follows: ER 1, 123; ER 2, 134; IR 1, 123; and IR 2, 120. Among those selected target lesions, 125 were chosen by at least two individual observers (all four readers selected the same target lesion in 58/125 (46.4%) instances, three readers in 40/125 (32%) and two observers in 27/125 (21.6%) instances). The interobserver agreement for PSMA-RADS scoring among identical target lesions was good (intraclass correlation coefficient (ICC) for four, three and two identical target lesions, ≥0.60, respectively). For lymph nodes, an excellent interobserver agreement was derived (ICC=0.79). The interobserver agreement for an overall scan impression based on PSMA-RADS was also excellent (ICC=0.84), with a significant difference for ER (ICC=0.97) vs. IR (ICC=0.74, P=0.005).
Conclusions: PSMA-RADS demonstrates a high concordance rate in this study, even among readers with different levels of experience. This suggests that PSMA-RADS can be effectively used for communication with clinicians and can be implemented in the collection of data for large prospective trials.
KW  - 18F-DCFPyL
KW  - Positronen-Emissions-Tomografie
KW  - PSMA-RADS
KW  - interreader
KW  - interobserver
KW  - PSMA
KW  - prostate cancer
KW  - RADS
KW  - reporting and data system
KW  - PET
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167788
SN  - 0161-5505
N1  - This research was originally published in JNM. Rudolf A. Werner, Ralph A. Bundschuh, Lena Bundschuh, Mehrbod S. Javadi, Jeffrey P. Leal, Takahiro Higuchi, Kenneth J. Pienta, Andreas K. Buck, Martin G. Pomper, Michael A. Gorin, Constantin Lapa and Steven P. Rowe. Interobserver Agreement for the Standardized Reporting System PSMA-RADS 1.0 on 18F-DCFPyL PET/CT Imaging. J Nucl Med 2018;59:1857-1864 © SNMMI.
ER  - 
TY  - JOUR
A1  - Israel, Ina
A1  - Ohsiek, Andrea
A1  - Al-Momani, Ehab
A1  - Albert-Weissenberger, Christiane
A1  - Stetter, Christian
A1  - Mencl, Stine
A1  - Buck, Andreas K.
A1  - Kleinschnitz, Christoph
A1  - Samnick, Samuel
A1  - Sirén, Anna-Leena
T1  - Combined [\(^{18}\)F]DPA-714 micro-positron emission tomography and autoradiography imaging of microglia activation after closed head injury in mice
JF  - Journal of Neuroinflammation
N2  - Background
Traumatic brain injury (TBI) is a major cause of death and disability. Neuroinflammation contributes to acute damage after TBI and modulates long-term evolution of degenerative and regenerative responses to injury. The aim of the present study was to evaluate the relationship of microglia activation to trauma severity, brain energy metabolism, and cellular reactions to injury in a mouse closed head injury model using combined in vivo PET imaging, ex vivo autoradiography, and immunohistochemistry.

Methods
A weight-drop closed head injury model was used to produce a mixed diffuse and focal TBI or a purely diffuse mild TBI (mTBI) in C57BL6 mice. Lesion severity was determined by evaluating histological damage and functional outcome using a standardized neuroscore (NSS), gliosis, and axonal injury by immunohistochemistry. Repeated intra-individual in vivo μPET imaging with the specific 18-kDa translocator protein (TSPO) radioligand [\(^{18}\)F]DPA-714 was performed on day 1, 7, and 16 and [\(^{18}\)F]FDG-μPET imaging for energy metabolism on days 2–5 after trauma using freshly synthesized radiotracers. Immediately after [\(^{18}\)F]DPA-714-μPET imaging on days 7 and 16, cellular identity of the [\(^{18}\)F]DPA-714 uptake was confirmed by exposing freshly cut cryosections to film autoradiography and successive immunostaining with antibodies against the microglia/macrophage marker IBA-1.

Results
Functional outcome correlated with focal brain lesions, gliosis, and axonal injury. [\(^{18}\)F]DPA-714-μPET showed increased radiotracer uptake in focal brain lesions on days 7 and 16 after TBI and correlated with reduced cerebral [\(^{18}\)F]FDG uptake on days 2–5, with functional outcome and number of IBA-1 positive cells on day 7. In autoradiography, [\(^{18}\)F]DPA-714 uptake co-localized with areas of IBA1-positive staining and correlated strongly with both NSS and the number of IBA1-positive cells, gliosis, and axonal injury. After mTBI, numbers of IBA-1 positive cells with microglial morphology increased in both brain hemispheres; however, uptake of [\(^{18}\)F]DPA-714 was not increased in autoradiography or in μPET imaging.

Conclusions
[\(^{18}\)F]DPA-714 uptake in μPET/autoradiography correlates with trauma severity, brain metabolic deficits, and microglia activation after closed head TBI.
KW  - neuroinflammation
KW  - TBI
KW  - immunohistochemistry
KW  - weight drop
KW  - PET
KW  - diffuse
KW  - focal
KW  - TSPO
KW  - autoradiography
KW  - IBA-1
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146606
VL  - 13
IS  - 140
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Beykan, Seval
A1  - Higuchi, Takahiro
A1  - Lückerath, Katharina
A1  - Weich, Alexander
A1  - Scheurlen, Michael
A1  - Bluemel, Christina
A1  - Herrmann, Ken
A1  - Buck, Andreas K.
A1  - Lassmann, Michael
A1  - Lapa, Constantin
A1  - Hänscheid, Heribert
T1  - The impact of \(^{177}\)Lu-octreotide therapy on \(^{99m}\)Tc-MAG3 clearance is not predictive for late nephropathy
JF  - Oncotarget
N2  - Peptide Receptor Radionuclide Therapy (PRRT) for the treatment of neuroendocrine tumors may lead to kidney deterioration. This study aimed to evaluate the suitability of \(^{99m}\)Tc-mercaptoacetyltriglycine (\(^{99m}\)Tc-MAG3) clearance for the early detection of PRRT-induced changes on tubular extraction (TE). TE rate (TER) was measured prior to 128 PRRT cycles (7.6±0.4 GBq \(^{177}\)Lu-octreotate/octreotide each) in 32 patients. TER reduction during PRRT was corrected for age-related decrease and analyzed for the potential to predict loss of glomerular filtration (GF). The GF rate (GFR) as measure for renal function was derived from serum creatinine. The mean TER was 234 ± 53 ml/min/1.73 m² before PRRT (baseline) and 221 ± 45 ml/min/1.73 m² after a median follow-up of 370 days. The age-corrected decrease (mean: -3%, range: -27% to +19%) did not reach significance (p=0.09) but significantly correlated with the baseline TER (Spearman p=-0.62, p<0.001). Patients with low baseline TER showed an improved TER after PRRT, high decreases were only observed in individuals with high baseline TER. Pre-therapeutic TER data were inferior to plasma creatinine-derived GFR estimates in predicting late nephropathy. TER assessed by \(^{99m}\)Tc-MAG3­clearance prior to and during PRRT is not suitable as early predictor of renal injury and an increased risk for late nephropathy.
KW  - renal scintigraphy
KW  - neuroendocrine tumor
KW  - 177Lu
KW  - MAG3
KW  - PRRT
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177318
VL  - 7
IS  - 27
ER  - 
TY  - JOUR
A1  - Herrmann, Ken
A1  - Buck, Andreas K.
A1  - Schuster, Tibor
A1  - Abbrederis, Kathrin
A1  - Blümel, Christina
A1  - Santi, Ivan
A1  - Rudelius, Martina
A1  - Wester, Hans-Jürgen
A1  - Peschel, Christian
A1  - Schwaiger, Markus
A1  - Dechow, Tobias
A1  - Keller, Ulrich
T1  - Week one FLT-PET response predicts complete remission to R-CHOP and survival in DLBCL
JF  - Oncotarget
N2  - Despite improved survival in the Rituximab (R) era, a considerable number of patients with diffuse large B-cell lymphoma (DLBCL) ultimately die from the disease. Functional imaging using [18F]fluorodeoxyglucose-PET is suggested for assessment of residual viable tumor very early during treatment but is compromised by non-specific tracer retention in inflammatory lesions. The PET tracer [18F]fluorodeoxythymidine (FLT) as surrogate marker of tumor proliferation may overcome this limitation. We present results of a prospective clinical study testing FLT-PET as superior and early predictor of response to chemotherapy and outcome in DLBCL. 54 patients underwent FLT-PET prior to and one week after the start of R-CHOP chemotherapy. Repetitive FLT-PET imaging was readily implemented into the diagnostic work-up. Our data demonstrate that the reduction of FLT standard uptake valuemean (SUVmean) and SUVmax one week after chemotherapy was significantly higher in patients achieving complete response (CR, n=48; non-CR, n=6; p<0.006). Martingale-residual and Cox proportional hazard analyses showed a significant monotonous decrease of mortality risk with increasing change in SUV. Consistent with these results, early FLT-PET response showed relevant discriminative ability in predicting CR. In conclusion, very early FLT-PET in the course of R-CHOP chemotherapy is feasible and enables identification of patients at risk for treatment failure.
KW  - [18F]Fluorodeoxythymidine
KW  - FLT-PET
KW  - positron emission tomography
KW  - DLBCL
KW  - lymphoma
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120659
SN  - 1949-2553
VL  - 5
IS  - 12
ER  - 
TY  - JOUR
A1  - Wondergem, Marielle J.
A1  - Herrmann, Ken
A1  - Syrbu, Sergei
A1  - Zijlstra, Josée M.
A1  - Hoetjes, Nikie
A1  - Hoekstra, Otto S.
A1  - Cillessen, Saskia A. G. M.
A1  - Moesbergen, Laura M.
A1  - Buck, Andreas K.
A1  - Vose, Julie M.
A1  - Juweid, Malik E.
T1  - 18 F-fluorothymidine uptake in follicular lymphoma and error-prone DNA repair
JF  - EJNMMI Research
N2  - BACKGROUND:
We observed a disproportional 18 F-fluorothymidine (F-FLT) uptake in follicular lymphoma (FL) relative to its low cell proliferation. We tested the hypothesis that the 'excess' uptake of 18 F-FLT in FL is related to error-prone DNA repair and investigated whether this also contributes to 18 F-FLT uptake in diffuse large B cell lymphoma (DLBCL).
METHODS:
We performed immunohistochemical stainings to assess the pure DNA replication marker MIB-1 as well as markers of both DNA replication and repair like PCNA, TK-1 and RPA1 on lymph node biopsies of 27 FLs and 35 DLBCLs. In 7 FL and 15 DLBCL patients, 18 F-FLT-PET had been performed.
RESULTS:
18 F-FLT uptake was lower in FL than in DLBCL (median SUVmax 5.7 vs. 8.9, p = 0,004), but the ratio of 18 F-FLT-SUVmax to percentage of MIB-1 positive cells was significantly higher in FL compared with DLBCL (p = 0.001). The median percentage of MIB-1 positive cells was 10% (range, 10% to 20%) in FL and 70% (40% to 80%) in DLBCL. In contrast, the median percentages of PCNA, TK-1 and RPA1 positive cells were 90% (range, 80 to 100), 90% (80 to 100) and 100% (80 to 100) in FL versus 90% (60 to 100), 90% (60 to 100) and 100% (80 to 100) in DLBCL, respectively.
CONCLUSIONS:
This is the first demonstration of a striking discordance between 18 F-FLT uptake in FL and tumour cell proliferation. High expression of DNA replication and repair markers compared with the pure proliferation marker MIB-1 in FL suggests that this discordance might be due to error-prone DNA repair. While DNA repair-related 18 F-FLT uptake considerably contributes to 18 F-FLT uptake in FL, its contribution to 18 F-FLT uptake in highly proliferative DLBCL is small. This apparently high contribution of DNA repair to the 18 F-FLT signal in FL may hamper studies where 18 F-FLT is used to assess response to cytostatic therapy or to distinguish between FL and transformed lymphoma.
KW  - 18-F-fluorothymidine uptake
KW  - positron emission tomography
KW  - follicular lymphoma
KW  - non-Hodgkin's lymphoma
KW  - DNA repair
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-121233
VL  - 4
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Linsenmann, Thomas
A1  - Lückerath, Katharina
A1  - Samnick, Samuel
A1  - Herrmann, Ken
A1  - Stoffer, Carolin
A1  - Ernestus, Ralf-Ingo
A1  - Buck, Andreas K.
A1  - Löhr, Mario
A1  - Monoranu, Camelia-Maria
T1  - Tumor-Associated Macrophages in Glioblastoma Multiforme—A Suitable Target for Somatostatin Receptor-Based Imaging and Therapy?
JF  - PLoS One
N2  - Background
Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. Tumor-associated macrophages (TAM) have been shown to promote malignant growth and to correlate with poor prognosis. [1,4,7,10-tetraazacyclododecane-NN′,N″,N′″-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) labeled with Gallium-68 selectively binds to somatostatin receptor 2A (SSTR2A) which is specifically expressed and up-regulated in activated macrophages. On the other hand, the role of SSTR2A expression on the cell surface of glioma cells has not been fully elucidated yet. The aim of this study was to non-invasively assess SSTR2A expression of both glioma cells as well as macrophages in GBM.

Methods
15 samples of patient-derived GBM were stained immunohistochemically for macrophage infiltration (CD68), proliferative activity (Ki67) as well as expression of SSTR2A. Anti-CD45 staining was performed to distinguish between resident microglia and tumor-infiltrating macrophages. In a subcohort, positron emission tomography (PET) imaging using \(^{68}Ga-DOTATATE\) was performed and the semiquantitatively evaluated tracer uptake was compared to the results of immunohistochemistry.

Results
The amount of microglia/macrophages ranged from <10% to >50% in the tumor samples with the vast majority being resident microglial cells. A strong SSTR2A immunostaining was observed in endothelial cells of proliferating vessels, in neurons and neuropile. Only faint immunostaining was identified on isolated microglial and tumor cells. Somatostatin receptor imaging revealed areas of increased tracer accumulation in every patient. However, retention of the tracer did not correlate with immunohistochemical staining patterns.

Conclusion
SSTR2A seems not to be overexpressed in GBM samples tested, neither on the cell surface of resident microglia or infiltrating macrophages, nor on the surface of tumor cells. These data suggest that somatostatin receptor directed imaging and treatment strategies are less promising in GBM.
KW  - glioma
KW  - positron emission tomography
KW  - glioblastoma multiforme
KW  - macrophages
KW  - somatostatin
KW  - microglial cells
KW  - immunostaining
KW  - magnetic resonance imaging
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125498
VL  - 10
IS  - 3
ER  - 
TY  - JOUR
A1  - Isaias, Ioannis Ugo
A1  - Spiegel, Jörg
A1  - Brumberg, Joachim
A1  - Cosgrove, Kelly P.
A1  - Marotta, Giorgio
A1  - Oishi, Naoya
A1  - Higuchi, Takahiro
A1  - Küsters, Sebastian
A1  - Schiller, Markus
A1  - Dillmann, Ulrich
A1  - van Dyck, Christopher H.
A1  - Buck, Andreas
A1  - Herrmann, Ken
A1  - Schloegl, Susanne
A1  - Volkmann, Jens
A1  - Lassmann, Michael
A1  - Fassbender, Klaus
A1  - Lorenz, Reinhard
A1  - Samnick, Samuel
T1  - Nicotinic acetylcholine receptor density in cognitively intact subjects at an early stage of Parkinson's disease
JF  - Frontiers in Aging Neuroscience
N2  - We investigated in vivo brain nicotinic acetylcholine receptor (nAChR) distribution in cognitively intact subjects with Parkinson's disease (PD) at an early stage of the disease. Fourteen patients and 13 healthy subjects were imaged with single photon emission computed tomography and the radiotracer 5-[(123)I]iodo-3-[2(S)-2-azetidinylmethoxy]pyridine ([(123)I]5IA). Patients were selected according to several criteria, including short duration of motor signs (<7 years) and normal scores at an extensive neuropsychological evaluation. In PD patients, nAChR density was significantly higher in the putamen, the insular cortex and the supplementary motor area and lower in the caudate nucleus, the orbitofrontal cortex, and the middle temporal gyrus. Disease duration positively correlated with nAChR density in the putamen ipsilateral (ρ = 0.56, p < 0.05) but not contralateral (ρ = 0.49, p = 0.07) to the clinically most affected hemibody. We observed, for the first time in vivo, higher nAChR density in brain regions of the motor and limbic basal ganglia circuits of subjects with PD. Our findings support the notion of an up-regulated cholinergic activity at the striatal and possibly cortical level in cognitively intact PD patients at an early stage of disease.
KW  - nicotinic receptors
KW  - Parkinson disease
KW  - 5IA-SPECT
KW  - dopamine acetylcholine
KW  - cognitive decline
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119351
VL  - 6
ER  - 
TY  - JOUR
A1  - Herrmann, Ken
A1  - Queiroz, Marcelo
A1  - Huellner, Martin W.
A1  - Barbosa, Felipe de Galiza
A1  - Buck, Andreas
A1  - Schaefer, Niklaus
A1  - Stolzman, Paul
A1  - Veit-Haibach, Patrick
T1  - Diagnostic performance of FDG-PET/MRI and WB-DW-MRI in the evaluation of lymphoma: a prospective comparison to standard FDG-PET/CT
JF  - BMC Cancer
N2  - Background: Use of FDG-PET/CT for staging and restaging of lymphoma patients is widely incorporated into current practice guidelines. Our aim was to prospectively evaluate the diagnostic performance of FDG-PET/MRI and WB-DW-MRI compared with FDG-FDG-PET/CT using a tri-modality PET/CT-MRI system. 
Methods: From 04/12 to 01/14, a total of 82 FDG-PET/CT examinations including an additional scientific MRI on a tri-modality setup were performed in 61 patients. FDG-PET/CT, FDG-PET/MRI, and WB-DW-MRI were independently analyzed. A lesion with a mean ADC below a threshold of 1.2 x 10\(^{-3}\) mm\(^2\)/s was defined as positive for restricted diffusion. FDG-PET/CT and FDG-PET/MRI were evaluated for the detection of lesions corresponding to lymphoma manifestations according to the German Hodgkin Study Group. Imaging findings were validated by biopsy (n = 21), by follow-up imaging comprising CT, FDG-PET/CT, and/or FDG-PET/MRI (n = 32), or clinically (n = 25) (mean follow-up: 9.1 months). 
Results: FDG-PET/MRI and FDG-PET/CT accurately detected 188 lesions in 27 patients. Another 54 examinations in 35 patients were negative. WB-DW-MRI detected 524 lesions, of which 125 (66.5 % of the aforementioned 188 lesions) were true positive. Among the 188 lesions positive for lymphoma, FDG-PET/MRI detected all 170 instances of nodal disease and also all 18 extranodal lymphoma manifestations; by comparison, WB-DW-MRI characterized 115 (67.6 %) and 10 (55.6 %) lesions as positive for nodal and extranodal disease, respectively. FDG-PET/MRI was superior to WB-DW-MRI in detecting lymphoma manifestations in patients included for staging (113 vs. 73), for restaging (75 vs. 52), for evaluation of high-(127 vs. 81) and low-grade lymphomas (61 vs. 46), and for definition of Ann Arbor stage (WB-DW-MRI resulted in upstaging in 60 cases, including 45 patients free of disease, and downstaging in 4). 
Conclusion: Our results indicate that FDG-PET/CT and FDG-PET/MRI probably have a similar performance in the clinical work-up of lymphomas. The performance of WB-DW-MRI was generally inferior to that of both FDG-PET-based methods but the technique might be used in specific scenarios, e.g., in low-grade lymphomas and during surveillance.
KW  - response evaluation
KW  - FDG-PET/MRI
KW  - FDG-PET/CT
KW  - FDG
KW  - WB-DW-MRI
KW  - whole-body
KW  - involvement
KW  - coefficient
KW  - lymphoma
KW  - B-cell lymphoma
KW  - diffusion weighted MRI
KW  - whole body MRI
KW  - Hodgkin-lymphoma
KW  - 1st International Workshop
KW  - malignant lymphoma
KW  - initial experience
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-136039
VL  - 15
IS  - 1002
ER  - 
TY  - JOUR
A1  - Graf, Nicolas
A1  - Li, Zhoulei
A1  - Herrmann, Ken
A1  - Weh, Daniel
A1  - Aichler, Michaela
A1  - Slawska, Jolanta
A1  - Walch, Axel
A1  - Peschel, Christian
A1  - Schwaiger, Markus
A1  - Buck, Andreas K.
A1  - Dechow, Tobias
A1  - Keller, Ulrich
T1  - Positron emission tomographic monitoring of dual phosphatidylinositol-3-kinase and mTOR inhibition in anaplastic large cell lymphoma
JF  - Oncotargets and Therapy
N2  - Background: Dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibition offers an attractive therapeutic strategy in anaplastic large cell lymphoma depending on oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) signaling. We tested the efficacy of a novel dual PI3K/mTOR inhibitor, NVP-BGT226 (BGT226), in two anaplastic large cell lymphoma cell lines in vitro and in vivo and performed an early response evaluation with positron emission tomography (PET) imaging using the standard tracer, 2-deoxy-2-[F-18] fluoro-D-glucose (FDG) and the thymidine analog, 3'-deoxy-3'-[F-18] fluorothymidine (FLT). 
Methods: The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling. FDG-PET and FLT-PET were performed in immunodeficient mice bearing either SU-DHL-1 or Karpas299 xenografts at baseline and 7 days after initiation of treatment with BGT226. Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects. 
Results: SU-DHL-1 cells showed sensitivity to BGT226 in vitro, with cell cycle arrest in G0/G1 phase and an IC50 in the low nanomolar range, in contrast with Karpas299 cells, which were mainly resistant to BGT226. In vivo, both FDG-PET and FLT-PET discriminated sensitive from resistant lymphoma, as indicated by a significant reduction of tumor-to-background ratios on day 7 in treated SU-DHL-1 lymphoma-bearing animals compared with the control group, but not in animals with Karpas299 xenografts. Imaging results correlated with a marked decrease in the proliferation marker Ki67, and a slight increase in the apoptotic marker, cleaved caspase 3, as revealed by immunostaining of explanted lymphoma tissue. 
Conclusion: Dual PI3K/mTOR inhibition using BGT226 is effective in ALK-positive anaplastic large cell lymphoma and can be monitored with both FDG-PET and FLT-PET early on in the course of therapy.
KW  - mammalian target of rapamycin
KW  - phosphatidylinositol-3-kinase
KW  - lymphoma
KW  - early response
KW  - NVP-BGT226
KW  - non-hodgkins-lymphoma
KW  - signaling pathway
KW  - FDG-PET
KW  - in-vivo
KW  - target
KW  - tumor
KW  - imaging proliferation
KW  - inhibition
KW  - positron emission tomography
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117915
VL  - 7
ER  - 
TY  - JOUR
A1  - Lückerath, Katharina
A1  - Lapa, Constantin
A1  - Malzahn, Uwe
A1  - Samnick, Samuel
A1  - Einsele, Herrmann
A1  - Buck, Andreas K.
A1  - Herrmann, Ken
A1  - Knop, Stefan
T1  - 18FDG-PET/CT for prognostic stratification of patients with multiple myeloma relapse after stem cell transplantation
N2  - The aim of this study was to investigate the prognostic value of 18F-fluoro-deoxyglucose positron emission tomography–computed tomography (18F-FDG-PET/CT) in 37 patients with a history of multiple myeloma (MM) and suspected or confirmed recurrence after stem cell transplantation (SCT). All patients had been heavily pre-treated. Time to progression (TTP) and overall survival (OS) were correlated to a number of different PET-derived as well as clinical parameters. Impact on patient management was assessed.

Absence of FDG-avid MM foci was a positive prognostic factor for both TTP and OS (p<0.01). Presence of >10 focal lesions correlated with both TTP (p<0.01) and OS (p<0.05). Interestingly, presence of >10 lesions in the appendicular skeleton proved to have the strongest association with disease progression. Intensity of glucose uptake and presence of extramedullary disease were associated with shorter TTP (p=0.037 and p=0.049, respectively). Manifestations in soft tissue structures turned out to be a strong negative predictor for both, TTP and OS (p<0.01, respectively). PET resulted in a change of management in 30% of patients.

Our data underline the prognostic value of 18F-FDG-PET/CT in MM patients also in the setting of post-SCT relapse. PET/CT has a significant impact on patient management.
KW  - 18FDG-PET/CT
KW  - Multiple myeloma
KW  - molecular imaging
KW  - FDG-PET/CT
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113107
ER  - 
TY  - JOUR
A1  - Lassmann, Michael
A1  - Preylowski, Veronika
A1  - Schlögl, Susanne
A1  - Schoenahl, Frédéric
A1  - Jörg, Gerhard
A1  - Samnick, Samuel
A1  - Buck, Andreas K.
T1  - Is the Image Quality of I-124-PET Impaired by an Automatic Correction of Prompt Gammas?
JF  - PLoS ONE
N2  - Objectives

The aim of this study is to evaluate the quality of I-124 PET images with and without prompt gamma compensation (PGC) by comparing the recovery coefficients (RC), the signal to noise ratios (SNR) and the contrast to F-18 and Ga-68. Furthermore, the influence of the PGC on the quantification and image quality is evaluated.

Methods

For measuring the image quality the NEMA NU2-2001 PET/SPECT-Phantom was used containing 6 spheres with a diameter between 10 mm and 37 mm placed in water with different levels of background activity. Each sphere was filled with the same activity concentration measured by an independently cross-calibrated dose calibrator. The “hot” sources were acquired with a full 3D PET/CT (Biograph mCT®, Siemens Medical USA). Acquisition times were 2 min for F-18 and Ga-68, and 10 min for I-124. For reconstruction an OSEM algorithm was applied. For I-124 the images were reconstructed with and without PGC. For the calculation of the RCs the activity concentrations in each sphere were determined; in addition, the influence of the background correction was studied.

Results

The RCs of Ga-68 are the smallest (79%). I-124 reaches similar RCs (87% with PGC, 84% without PGC) as F-18 (84%). showing that the quantification of I-124 images is similar to F-18 and slightly better than Ga-68. With background activity the contrast of the I-124 PGC images is similar to Ga-68 and F-18 scans. There was lower background activity in the I-124 images without PGC, which probably originates from an overcorrection of the scatter contribution. Consequently, the contrast without PGC was much higher than with PGC. As a consequence PGC should be used for I-124.

Conclusions

For I-124 there is only a slight influence on the quantification depending on the use of the PGC. However, there are considerable differences with respect to I-124 image quality.
KW  - cancer treatment
KW  - health care
KW  - isotopes
KW  - photons
KW  - positron emission tomography
KW  - signal to noise ratio
KW  - super ultraviolet
KW  - thyroid carcinomas
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96863
ER  - 
TY  - JOUR
A1  - Weich, Alexander
A1  - Werner, Rudolf A.
A1  - Buck, Andreas K.
A1  - Hartrampf, Philipp E.
A1  - Serfling, Sebastian E.
A1  - Scheurlen, Michael
A1  - Wester, Hans-Jürgen
A1  - Meining, Alexander
A1  - Kircher, Stefan
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
A1  - Kircher, Malte
T1  - CXCR4-Directed PET/CT in Patients with Newly Diagnosed Neuroendocrine Carcinomas
JF  - Diagnostics
N2  - We aimed to elucidate the diagnostic potential of the C-X-C motif chemokine receptor 4 (CXCR4)-directed positron emission tomography (PET) tracer \(^{68}\)Ga-Pentixafor in patients with poorly differentiated neuroendocrine carcinomas (NEC), relative to the established reference standard \(^{18}\)F-FDG PET/computed tomography (CT). In our database, we retrospectively identified 11 treatment-naïve patients with histologically proven NEC, who underwent \(^{18}\)F-FDG and CXCR4-directed PET/CT for staging and therapy planning. The images were analyzed on a per-patient and per-lesion basis and compared to immunohistochemical staining (IHC) of CXCR4 from PET-guided biopsies. \(^{68}\)Ga-Pentixafor visualized tumor lesions in 10/11 subjects, while \(^{18}\)F-FDG revealed sites of disease in all 11 patients. Although weak to moderate CXCR4 expression could be corroborated by IHC in 10/11 cases, \(^{18}\)F-FDG PET/CT detected significantly more tumor lesions (102 vs. 42; total lesions, n = 107; p < 0.001). Semi-quantitative analysis revealed markedly higher 18F-FDG uptake as compared to \(^{68}\)Ga-Pentixafor (maximum and mean standardized uptake values (SUV) and tumor-to-background ratios (TBR) of cancerous lesions, SUVmax: 12.8 ± 9.8 vs. 5.2 ± 3.7; SUVmean: 7.4 ± 5.4 vs. 3.1 ± 3.2, p < 0.001; and, TBR 7.2 ± 7.9 vs. 3.4 ± 3.0, p < 0.001). Non-invasive imaging of CXCR4 expression in NEC is inferior to the reference standard \(^{18}\)F-FDG PET/CT.
KW  - CXCR4
KW  - NET
KW  - NEC
KW  - <sup>68</sup>Ga-Pentixafor
KW  - <sup>18</sup>F-FDG
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234231
SN  - 2075-4418
VL  - 11
IS  - 4
ER  - 
TY  - JOUR
A1  - Li, Xiang
A1  - Samnick, Samuel
A1  - Lapa, Constantin
A1  - Israel, Ina
A1  - Buck, Andreas K.
A1  - Kreissl, Michael C.
A1  - Bauer, Wolfgang
T1  - 68Ga-DOTATATE PET/CT for the detection of inflammation of large arteries: correlation with18F-FDG, calcium burden and risk factors
N2  - Background: Ga-[1,4,7,10-tetraazacyclododecane-N,N0,N00,N000-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) positron emission tomography (PET) is commonly used for the visualization of somatostatin receptor (SSTR)-positive neuroendocrine tumors. SSTR is also known to be expressed on macrophages, which play a major role in inflammatory processes in the walls of coronary arteries and large vessels. Therefore, imaging SSTR expression has the potential to visualize vulnerable plaques. We assessed 68Ga-DOTATATE accumulation in large vessels in comparison to 18F-2-fluorodeoxyglucose (FDG) uptake, calcified plaques (CPs), and cardiovascular risk factors. Methods: Sixteen consecutive patients with neuroendocrine tumors or thyroid cancer underwent both 68Ga-DOTATATE and 18F-FDG PET/CT for staging or restaging purposes. Detailed clinical data, including common cardiovascular risk factors, were recorded. For a separate assessment, they were divided into a high-risk and a low-risk group. In each patient, we calculated the maximum target-to-background ratio (TBR) of eight arterial segments. The correlation of the TBRmean of both tracers with risk factors including plaque burden was assessed. Results: The mean TBR of 68Ga-DOTATATE in all large arteries correlated significantly with the presence of CPs (r = 0.52; p < 0.05), hypertension (r = 0.60; p < 0.05), age (r = 0.56; p < 0.05), and uptake of 18F-FDG (r = 0.64; p < 0.01). There was one significant correlation between 18F-FDG uptake and hypertension (0.58; p < 0.05). Out of the 37 sites with the highest focal 68Ga-DOTATATE uptake, 16 (43.2%) also had focal 18F-FDG uptake. Of 39 sites with the highest 18F-FDG uptake, only 11 (28.2%) had a colocalized 68Ga-DOTATATE accumulation. Conclusions: In this series of cancer patients, we found a stronger association of increased 68Ga-DOTATATE uptake with known risk factors of cardiovascular disease as compared to 18F-FDG, suggesting a potential role for plaque imaging in large arteries. Strikingly, we found that focal uptake of 68Ga-DOTATATE and 18F-FDG does not colocalize in a significant number of lesions.
KW  - Medizin
KW  - Atherosclerotic plaque
KW  - 68Ga-DOTATATE
KW  - Somatostatin receptor
KW  - Cardiovascular risk factors
KW  - Macrophage
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76231
ER  - 
TY  - JOUR
A1  - Rasche, Leo
A1  - Kumar, Manoj
A1  - Gershner, Grant
A1  - Samant, Rohan
A1  - Van Hemert, Rudy
A1  - Heidemeier, Anke
A1  - Lapa, Constantin
A1  - Bley, Thorsten
A1  - Buck, Andreas
A1  - McDonald, James
A1  - Hillengass, Jens
A1  - Epstein, Joshua
A1  - Thanendrarajan, Sharmilan
A1  - Schinke, Carolina
A1  - van Rhee, Frits
A1  - Zangari, Maurizio
A1  - Barlogie, Bart
A1  - Davies, Faith E.
A1  - Morgan, Gareth J.
A1  - Weinhold, Niels
T1  - Lack of Spleen Signal on Diffusion Weighted MRI is associated with High Tumor Burden and Poor Prognosis in Multiple Myeloma: A Link to Extramedullary Hematopoiesis?
JF  - Theranostics
N2  - Due to the low frequency of abnormalities affecting the spleen, this organ is often overlooked during radiological examinations. Here, we report on the unexpected finding, that the spleen signal on diffusion-weighted MRI (DW-MRI) is associated with clinical parameters in patients with plasma cell dyscrasias. Methods: We investigated the spleen signal on DW-MRI together with clinical and molecular parameters in 295 transplant-eligible newly diagnosed Multiple Myeloma (NDMM) patients and in 72 cases with monoclonal gammopathy of undetermined significance (MGUS). Results: Usually, the spleen is the abdominal organ with the highest intensities on DW-MRI. Yet, significant signal loss on DW-MRI images was seen in 71 of 295 (24%) NDMM patients. This phenomenon was associated with the level of bone marrow plasmacytosis (P=1x10(-10)) and International Staging System 3 (P=0.0001) but not with gain(1q), and del(17p) or plasma cell gene signatures. The signal was preserved in 72 individuals with monoclonal gammopathy of undetermined significance and generally re-appeared in MM patients responding to treatment, suggesting that lack of signal reflects increased tumor burden. While absence of spleen signal in MM patients with high risk disease defined a subgroup with very poor outcome, re-appearance of the spleen signal after autologous stem cell transplantation was seen in patients with improved outcome. Our preliminary observation suggests that extramedullary hematopoiesis in the spleen is a factor that modifies the DW-MRI signal of this organ. Conclusions: The DW-MRI spleen signal is a promising marker for tumor load and provides prognostic information in MM.
KW  - multiple myeloma
KW  - diffusion weighted mri
KW  - spleen
KW  - tumor burden
KW  - high risk
KW  - extramedullary hematopoiesis
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224982
VL  - 9
IS  - 16
ER  - 
TY  - JOUR
A1  - Kreissl, Michael C.
A1  - Hänscheid, Heribert
A1  - Löhr, Mario
A1  - Verburg, Frederik A.
A1  - Schiller, Markus
A1  - Lassmann, Michael
A1  - Reiners, Christoph
A1  - Samnick, Samuel S.
A1  - Buck, Andreas K.
A1  - Flentje, Michael
A1  - Sweeney, Reinhart A.
T1  - Combination of peptide receptor radionuclide therapy with fractionated external beam radiotherapy for treatment of advanced symptomatic meningioma
N2  - Background: External beam radiotherapy (EBRT) is the treatment of choice for irresectable meningioma. Due to the strong expression of somatostatin receptors, peptide receptor radionuclide therapy (PRRT) has been used in advanced cases. We assessed the feasibility and tolerability of a combination of both treatment modalities in advanced symptomatic meningioma. Methods: 10 patients with irresectable meningioma were treated with PRRT (177Lu-DOTA0,Tyr3 octreotate or - DOTA0,Tyr3 octreotide) followed by external beam radiotherapy (EBRT). EBRT performed after PRRT was continued over 5–6 weeks in IMRT technique (median dose: 53.0 Gy). All patients were assessed morphologically and by positron emission tomography (PET) before therapy and were restaged after 3–6 months. Side effects were evaluated according to CTCAE 4.0. Results: Median tumor dose achieved by PRRT was 7.2 Gy. During PRRT and EBRT, no side effects>CTCAE grade 2 were noted. All patients reported stabilization or improvement of tumor-associated symptoms, no morphologic tumor progression was observed in MR-imaging (median follow-up: 13.4 months). The median pre-therapeutic SUVmax in the meningiomas was 14.2 (range: 4.3–68.7). All patients with a second PET after combined PRRT + EBRT showed an increase in SUVmax (median: 37%; range: 15%–46%) to a median value of 23.7 (range: 8.0–119.0; 7 patients) while PET-estimated volume generally decreased to 81 ± 21% of the initial volume. Conclusions: The combination of PRRT and EBRT is feasible and well tolerated. This approach represents an attractive strategy for the treatment of recurring or progressive symptomatic meningioma, which should be further evaluated.
KW  - Medizin
KW  - PRRT
KW  - Peptide receptor radionuclide therapy
KW  - Meningioma
KW  - Radiotherapy
KW  - EBRT
KW  - Combination
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75540
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Weinzierl, Franz-Xaver
A1  - Seitz, Anna Katharina
A1  - Kübler, Hubert
A1  - Essler, Markus
A1  - Buck, Andreas K.
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
T1  - Any decline in prostate-specific antigen levels identifies survivors scheduled for prostate-specific membrane antigen-directed radioligand therapy
JF  - The Prostate
N2  - Background
Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) is increasingly incorporated in the therapeutic algorithm of patients with metastatic castration-resistant prostate cancer (mCRPC). We aimed to elucidate the predictive performance of early biochemical response for overall survival (OS).
Materials and Methods
In this bicentric analysis, we included 184 mCRPC patients treated with \(^{177}\)Lu-PSMA RLT. Response to treatment was defined as decrease in prostate-specific antigen (PSA) levels 8 weeks after the first cycle of RLT (any decline or >50% according to Prostate Cancer Working Group 3). OS of responders and nonresponders was then compared using Kaplan–Meier curves and log-rank comparison.
Results
A total of 114/184 patients (62.0%) showed any PSA decline (PSA response >50%, 55/184 [29.9%]). For individuals exhibiting a PSA decline >50%, OS of 19 months was significantly longer relative to nonresponders (13 months; hazard ratio of death [HR] = 0.64, 95% confidence interval [95% CI] = 0.44–0.93; p = 0.02). However, the difference was even more pronounced for any PSA decline, with an OS of 19 months in responders, but only 8 months in nonresponders (HR = 0.39, 95% CI = 0.25–0.60; p < 0.001).
Conclusions
In mCRPC patients scheduled for RLT, early biochemical response was tightly linked to prolonged survival, irrespective of the magnitude of PSA decline. As such, even in patients with PSA decrease of less than 50%, RLT should be continued.
KW  - prostate cancer
KW  - theranostics
KW  - PSMA‐617
KW  - PSA response
KW  - PSMA I&T
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318766
VL  - 82
IS  - 14
SP  - 1406
EP  - 1412
ER  - 
TY  - JOUR
A1  - Lenschow, Christina
A1  - Fuss, Carmina Teresa
A1  - Kircher, Stefan
A1  - Buck, Andreas
A1  - Kickuth, Ralph
A1  - Reibetanz, Joachim
A1  - Wiegering, Armin
A1  - Stenzinger, Albrecht
A1  - Hübschmann, Daniel
A1  - Germer, Christoph Thomas
A1  - Fassnacht, Martin
A1  - Fröhling, Stefan
A1  - Schlegel, Nicolas
A1  - Kroiss, Matthias
T1  - Case Report: Abdominal Lymph Node Metastases of Parathyroid Carcinoma: Diagnostic Workup, Molecular Diagnosis, and Clinical Management
JF  - Frontiers in Endocrinology
N2  - Parathyroid carcinoma (PC) is an orphan malignancy accounting for only ~1% of all cases with primary hyperparathyroidism. The localization of recurrent PC is of critical importance and can be exceedingly difficult to diagnose and sometimes futile when common sites of recurrence in the neck and chest cannot be confirmed. Here, we present the diagnostic workup, molecular analysis and multimodal therapy of a 46-year old woman with the extraordinary manifestation of abdominal lymph node metastases 12 years after primary diagnosis of PC. The patient was referred to our endocrine tumor center in 2016 with the aim to localize the tumor causative of symptomatic biochemical recurrence. In view of the extensive previous workup we decided to perform [18F]FDG-PET-CT. A pathological lymph node in the liver hilus showed slightly increased FDG-uptake and hence was suspected as site of recurrence. Selective venous sampling confirmed increased parathyroid hormone concentration in liver veins. Abdominal lymph node metastasis was resected and histopathological examination confirmed PC. Within four months, the patient experienced biochemical recurrence and based on high tumor mutational burden detected in the surgical specimen by whole exome sequencing the patient received immunotherapy with pembrolizumab that led to a biochemical response. Subsequent to disease progression repeated abdominal lymph node resection was performed in 10/2018, 01/2019 and in 01/2020. Up to now (12/2020) the patient is biochemically free of disease. In conclusion, a multimodal diagnostic approach and therapy in an interdisciplinary setting is needed for patients with rare endocrine tumors. Molecular analyses may inform additional treatment options including checkpoint inhibitors such as pembrolizumab.
KW  - parathyroid carcinoma
KW  - abdominal lymph node metastases
KW  - molecular diagnostics
KW  - repeated surgery
KW  - [18F]FDG-PET-CT
KW  - immune check inhibitor
KW  - pembrolizumab
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-233362
SN  - 1664-2392
VL  - 12
ER  - 
TY  - JOUR
A1  - Hendricks, Anne
A1  - Lenschow, Christina
A1  - Kroiss, Matthias
A1  - Buck, Andreas
A1  - Kickuth, Ralph
A1  - Germer, Christoph-Thomas
A1  - Schlegel, Nicolas
T1  - Evaluation of diagnostic efficacy for localization of parathyroid adenoma in patients with primary hyperparathyroidism undergoing repeat surgery
JF  - Langenbeck's Archives of Surgery
N2  - Purpose
Repeat surgery in patients with primary hyperparathyroidism (pHPT) is associated with an increased risk of complications and failure. This stresses the need for optimized strategies to accurately localize a parathyroid adenoma before repeat surgery is performed. However, evidence on the extent of required diagnostics for a structured approach is sparse.
Methods
A retrospective single-center evaluation of 28 patients with an indication for surgery due to pHPT and previous thyroid or parathyroid surgery was performed. Diagnostic workup, surgical approach, and outcome in terms of complications and successful removement of parathyroid adenoma with biochemical cure were evaluated.
Results
Neck ultrasound, sestamibi scintigraphy, C11-methionine PET-CT, and selective parathyroid hormone venous sampling, but not MRI imaging, effectively detected the presence of a parathyroid adenoma with high positive predictive values. Biochemical cure was revealed by normalization of calcium and parathormone levels 24-48h after surgery and was achieved in 26/28 patients (92.9%) with an overall low rate of complications. Concordant localization by at least two diagnostic modalities enabled focused surgery with success rates of 100%, whereas inconclusive localization significantly increased the rate of bilateral explorations and significantly reduced the rate of biochemical cure to 80%.
Conclusion
These findings suggest that two concordant diagnostic modalities are sufficient to accurately localize parathyroid adenoma before repeat surgery for pHPT. In cases of poor localization, extended diagnostic procedures are warranted to enhance surgical success rates. We suggest an algorithm for better orientation when repeat surgery is intended in patients with pHPT.
KW  - Primary hyperparathyroidism (pHPT)
KW  - preoperative localization
KW  - repeat surgery
KW  - diagnostics
KW  - imaging
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267520
SN  - 1435-2451
VL  - 406
IS  - 5
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Sheikhbahaei, Sara
A1  - Jones, Krystyna M.
A1  - Javadi, Mehrbod S.
A1  - Solnes, Lilja B.
A1  - Ross, Ashley E.
A1  - Allaf, Mohamad E.
A1  - Pienta, Kenneth J.
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Gorin, Micheal A.
A1  - Rowe, Steven P.
T1  - Patterns of uptake of prostate-specific membrane antigen (PSMA)-targeted \(^{18}\)F-DCFPyL in peripheral ganglia
JF  - Annals of Nuclear Medicine
N2  - Objective: Radiotracers targeting prostate-specific membrane antigen (PSMA) have increasingly been recognized as showing uptake in a number of normal structures, anatomic variants, and non-prostate-cancer pathologies. We aimed to explore the frequency and degree of uptake in peripheral ganglia in patients undergoing PET with the PSMA-targeted agent \(^{18}\)F-DCFPyL. 
Methods: A total of 98 patients who underwent \(^{18}\)F-DCFPyL PET/CT imaging were retrospectively analyzed. This included 76 men with prostate cancer (PCa) and 22 patients with renal cell carcinoma (RCC; 13 men, 9 women). Scans were evaluated for uptake in the cervical, stellate, celiac, lumbar and sacral ganglia. Maximum standardized uptake value corrected to body weight (SUV\(_{max}\)), and maximum standardized uptake value corrected to lean body mass (SUL\(_{max}\)) were recorded for all ganglia with visible uptake above background. Ganglia-to-background ratios were calculated by dividing the SUV\(_{max}\) and SUL\(_{max}\) values by the mean uptake in the ascending aorta (Aortamean) and the right gluteus muscle (Gluteusmean). 
Results: Overall, 95 of 98 (96.9%) patients demonstrated uptake in at least one of the evaluated peripheral ganglia. With regard to the PCa cohort, the most frequent sites of radiotracer accumulation were lumbar ganglia (55/76, 72.4%), followed by the cervical ganglia (51/76, 67.1%). Bilateral uptake was found in the majority of cases [lumbar 44/55 (80%) and cervical 30/51 (58.8%)]. Additionally, discernible radiotracer uptake was recorded in 50/76 (65.8%) of the analyzed stellate ganglia and in 45/76 (59.2%) of the celiac ganglia, whereas only 5/76 (6.6%) of the sacral ganglia demonstrated \(^{18}\)F-DCFPyL accumulation. Similar findings were observed for patients with RCC, with the most frequent locations of radiotracer uptake in both the lumbar (20/22, 90.9%) and cervical ganglia (19/ 22, 86.4%). No laterality preference was found in mean PSMA-ligand uptake for either the PCa or RCC cohorts. 
Conclusion: As PSMA-targeted agents become more widely disseminated, the patterns of uptake in structures that are not directly relevant to patients’ cancers must be understood. This is the first systematic evaluation of the uptake of \(^{18}\)F-DCFPyL in ganglia demonstrating a general trend with a descending frequency of radiotracer accumulation in lumbar, cervical, stellate, celiac, and sacral ganglia. The underlying biology that leads to variability of PSMA-targeted radiotracers in peripheral ganglia is not currently understood, but may provide opportunities for future research.
KW  - 18F-DCFPL
KW  - Positronen-Emissions-Tomografie
KW  - Prostata
KW  - PSMA
KW  - Ganglia
KW  - Pitfall
KW  - PET
KW  - Tracer
KW  - Radiotracer
KW  - Imaging pitfalls
KW  - Prostate Cancer
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166971
SN  - 0914-7187
VL  - 31
IS  - 9
ER  - 
TY  - INPR
A1  - Werner, Rudolf A.
A1  - Andree, Christian
A1  - Javadi, Mehrbod S.
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Rowe, Steven P.
A1  - Pienta, Kenneth J.
T1  - A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging
T2  - Urology - The Gold Journal
N2  - No abstract available.
KW  - 18F-DCFPyL
KW  - Virchow Node
KW  - PSMA-PET
KW  - Virchow Node
KW  - Positron Emission Tomography
KW  - Prostate Cancer
KW  - PET
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161103
SN  - 0090-4295
N1  - This is the accepted manuscript of Rudolf Werner, Christian Andree, Mehrbod S. Javadi, Constantin Lapa, Andreas K. Buck, Takahiro Higuchi, Martin G. Pomper, Michael A.Gorin, Steven P.Rowe, Kenneth J. Pienta: A Voice From the Past: Re-Discovering the Virchow Node with PSMA-Targeted 18F-DCFPyL PET Imaging. Published in Urology 117(2018), p. 18-21. https://doi.org/10.1016/j.urology.2018.03.030
N1  - Die finale Version dieses Artikels steht unter https://doi.org/10.1016/j.urology.2018.03.030 oder https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-164632 open access zur Verfügung.
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Andree, Christian
A1  - Javadi, Mehrbod S.
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Rowe, Steven P.
A1  - Pienta, Kenneth J.
T1  - A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging
JF  - Urology - The Gold Journal
N2  - No abstract available.
KW  - 18F-DCFPyL
KW  - PET
KW  - PSMA-PET
KW  - Positron Emission Tomography
KW  - Prostate Cancer
KW  - Virchow Node
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164632
SN  - 0090-4295
VL  - 117
ER  - 
TY  - JOUR
A1  - Eissler, Cristoph
A1  - Werner, Rudolf A.
A1  - Arias-Loza, Paula
A1  - Nose, Naoko
A1  - Chen, Xinyu
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
T1  - The number of frames on ECG-gated \(^{18}\)F-FDG small animal PET has a significant impact on LV systolic and diastolic functional parameters
JF  - Molecular Imaging
N2  - Objectives. This study is aimed at investigating the impact of frame numbers in preclinical electrocardiogram- (ECG-) gated \(^{18}\)F-fluorodeoxyglucose (\(^{18}\)F-FDG) positron emission tomography (PET) on systolic and diastolic left ventricular (LV) parameters in rats. Methods. \(^{18}\)F-FDG PET imaging using a dedicated small animal PET system with list mode data acquisition and continuous ECG recording was performed in diabetic and control rats. The list-mode data was sorted and reconstructed with different numbers of frames (4, 8, 12, and 16) per cardiac cycle into tomographic images. Using an automatic ventricular edge detection software, left ventricular (LV) functional parameters, including ejection fraction (EF), end-diastolic (EDV), and end-systolic volume (ESV), were calculated. Diastolic variables (time to peak filling (TPF), first third mean filling rate (1/3 FR), and peak filling rate (PFR)) were also assessed. Results. Significant differences in multiple parameters were observed among the reconstructions with different frames per cardiac cycle. EDV significantly increased by numbers of frames (353.8 & PLUSMN; 57.7 mu l*, 380.8 & PLUSMN; 57.2 mu l*, 398.0 & PLUSMN; 63.1 mu l*, and 444.8 & PLUSMN; 75.3 mu l at 4, 8, 12, and 16 frames, respectively; *P < 0.0001 vs. 16 frames), while systolic (EF) and diastolic (TPF, 1/3 FR and PFR) parameters were not significantly different between 12 and 16 frames. In addition, significant differences between diabetic and control animals in 1/3 FR and PFR in 16 frames per cardiac cycle were observed (P < 0.005), but not for 4, 8, and 12 frames. Conclusions. Using ECG-gated PET in rats, measurements of cardiac function are significantly affected by the frames per cardiac cycle. Therefore, if you are going to compare those functional parameters, a consistent number of frames should be used.
KW  - Myocardial-perfusion SPECT
KW  - left-ventricular function
KW  - ejection fraction
KW  - MRI
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265778
VL  - 2021
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Ilhan, Harun
A1  - Lehner, Sebastian
A1  - Papp, László
A1  - Zsótér, Norbert
A1  - Schatka, Imke
A1  - Muegge, Dirk O.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Bartenstein, Peter
A1  - Bengel, Frank
A1  - Essler, Markus
A1  - Lapa, Constantin
A1  - Bundschuh, Ralph A.
T1  - Pre-therapy Somatostatin-Receptor-Based Heterogeneity Predicts Overall Survival in Pancreatic Neuroendocrine Tumor Patients Undergoing Peptide Receptor Radionuclide Therapy
JF  - Molecular Imaging and Biology
N2  - Purpose: Early identification of aggressive disease could improve decision-support in pancreatic neuroendocrine tumor (pNET) patients prior to peptide receptor radionuclide therapy (PRRT). The prognostic value of intratumoral textural features (TF) determined by baseline somatostatin receptor (SSTR)-PET before PRRT was analyzed.
Procedures: 31 patients with G1/G2 pNET were enrolled (G2, n=23/31). Prior to PRRT with [\(^{177}\)Lu]DOTATATE (mean, 3.6 cycles), baseline SSTR-PET/CT was performed. By segmentation of 162 (median per patient, 5) metastases, intratumoral TF were computed. The impact of conventional PET parameters  (SUV\(_{mean/max}\)), imaging-based TF as well as clinical parameters (Ki67, CgA) for prediction of both progression-free (PFS) and overall survival (OS) after PRRT was evaluated.
Results: Within a median follow-up of 3.7y, tumor progression was detected in 21 patients (median, 1.5y) and 13/31 deceased (median, 1.9y). In ROC analysis, the TF Entropy, reflecting derangement on a voxel-by-voxel level, demonstrated predictive capability for OS (cutoff=6.7, AUC=0.71, p=0.02). Of note, increasing Entropy could predict a longer survival (>6.7, OS=2.5y, 17/31), whereas less voxel-based derangement portended inferior outcome (<6.7, OS=1.9y, 14/31). These findings were supported in a G2 subanalysis (>6.9, OS=2.8y, 9/23 vs. <6.9, OS=1.9y, 14/23). Kaplan-Meier analysis revealed a significant distinction between high- and low-risk groups using Entropy (n=31, p<0.05). For those patients below the ROC-derived threshold, the relative risk of death after PRRT was 2.73 (n=31, p=0.04). Ki67 was negatively associated with PFS (p=0.002); however, SUVmean/max failed in prognostication (n.s.).
Conclusions: In contrast to conventional PET parameters, assessment of intratumoral heterogeneity demonstrated superior prognostic performance in pNET patients undergoing PRRT. This novel PET-based strategy of outcome prediction prior to PRRT might be useful for patient risk stratification.
KW  - tumor heterogeneity
KW  - Positronen-Emissions-Tomografie
KW  - PET
KW  - PET/CT
KW  - pancreas
KW  - SSTR
KW  - [177Lu]-DOTATATE/-DOTATOC
KW  - [68Ga]
KW  - neuroendocrine tumor
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167168
SN  - 1536-1632
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
A1  - Bundschuh, Lena
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Weich, Alexander
A1  - Sheikhbahaei, Sara
A1  - Pienta, Kenneth J.
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
T1  - MI-RADS: Molecular Imaging Reporting and Data Systems – A Generalizable Framework for Targeted Radiotracers with Theranostic Implications
JF  - Annals of Nuclear Medicine
N2  - Both prostate-specific membrane antigen (PSMA)- and somatostatin receptor (SSTR)-targeted positron emission tomography (PET) imaging agents for staging and restaging of prostate carcinoma or neuroendocrine tumors, respectively, are seeing rapidly expanding use. In addition to diagnostic applications, both classes of radiotracers can be used to triage patients for theranostic endoradiotherapy. While interpreting PSMA- or SSTR-targeted PET/computed tomography (CT) scans, the reader has to be aware of certain pitfalls. Adding to the complexity of the interpretation of those imaging agents, both normal biodistribution, and also false-positive and -negative findings differ between PSMA- and SSTR-targeted PET radiotracers. Herein summarized under the umbrella term molecular imaging reporting and data systems (MI-RADS), two novel RADS classifications for PSMA- and SSTR-targeted PET imaging are described (PSMA- and SSTR-RADS). Both framework systems may contribute to increase the level of a reader’s confidence and to navigate the imaging interpreter through indeterminate lesions, so that appropriate workup for equivocal findings can be pursued. Notably, PSMA- and SSTR-RADS are structured in a reciprocal fashion, i.e. if the reader is familiar with one system, the other system can readily be applied as well. In the present review we will discuss the most common pitfalls on PSMA- and SSTR-targeted PET/CT, briefly introduce PSMA- and SSTR-RADS, and define a future role of the umbrella framework MI-RADS compared to other harmonization systems.
KW  - PET
KW  - Positronen-Emissions-Tomografie
KW  - prostate cancer
KW  - neuroendocrine tumor
KW  - prostate-specific membrane antigen (PSMA)
KW  - somatostatin receptor (SSTR)
KW  - positron emission tomography
KW  - theranostics
KW  - standardization
KW  - RADS
KW  - reporting and data systems
KW  - personalized medicine
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166995
SN  - 0914-7187
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Bundschuh, Ralph A.
A1  - Higuchi, Takahiro
A1  - Javadi, Mehrbod S.
A1  - Rowe, Steven P.
A1  - Zsótér, Norbert
A1  - Kroiss, Matthias
A1  - Fassnacht, Martin
A1  - Buck, Andreas K.
A1  - Kreissl, Michael C.
A1  - Lapa, Constantin
T1  - Volumetric and Texture Analysis of Pretherapeutic \(^{18}\)F-FDG PET can Predict Overall Survival in Medullary Thyroid Cancer Patients Treated with Vandetanib
JF  - Endocrine
N2  - Purpose: The metabolically most active lesion in 2-deoxy-2-(\(^{18}\)F)fluoro-D-glucose (\(^{18}\)F-FDG) PET/CT can predict progression-free survival (PFS) in patients with medullary thyroid carcinoma (MTC) starting treatment with the tyrosine kinase inhibitor (TKI) vandetanib. However, this metric failed in overall survival (OS) prediction. In the present proof of concept study, we aimed to explore the prognostic value of intratumoral textural features (TF) as well as volumetric parameters (total lesion glycolysis, TLG) derived by pre-therapeutic \(^{18}\)F-FDG PET. 
Methods: Eighteen patients with progressive MTC underwent baseline \(^{18}\)F-FDG PET/CT prior to and 3 months after vandetanib initiation. By manual segmentation of the tumor burden at baseline and follow-up PET, intratumoral TF and TLG were computed. The ability of TLG, imaging-based TF, and clinical parameters (including age, tumor marker doubling times, prior therapies and RET (rearranged during transfection) mutational status) for prediction of both PFS and OS were evaluated. 
Results: The TF Complexity and the volumetric parameter TLG obtained at baseline prior to TKI initiation successfully differentiated between low- and high-risk patients. Complexity allocated 10/18 patients to the high-risk group with an OS of 3.3y (vs. low-risk group, OS=5.3y, 8/18, AUC=0.78, P=0.03). Baseline TLG designated 11/18 patients to the high-risk group (OS=3.5y vs. low-risk group, OS=5y, 7/18, AUC=0.83, P=0.005). The Hazard Ratio for cancer-related death was 6.1 for Complexity (TLG, 9.5). Among investigated clinical parameters, the age at initiation of TKI treatment reached significance for PFS prediction (P=0.02, OS, n.s.). 
Conclusions: The TF Complexity and the volumetric parameter TLG are both independent parameters for OS prediction.
KW  - personalized medicine
KW  - Positronen-Emissions-Tomografie
KW  - medullary thyroid carcinoma
KW  - tyrosine kinase inhibitor
KW  - TKI
KW  - vandetanib
KW  - 18F-FDG
KW  - positron emission tomography
KW  - 2-deoxy-2-(18F)fluoro-D-glucose
KW  - PET
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167910
SN  - 1355-008X
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Weich, Alexander
A1  - Kircher, Malte
A1  - Solnes, Lilja B.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Rowe, Steven
A1  - Lapa, Constantin
T1  - The theranostic promise for neuroendocrine tumors in the late 2010s – Where do we stand, where do we go?
JF  - Theranostics
N2  - More than 25 years after the first peptide receptor radionuclide therapy (PRRT), the concept of somatostatin receptor (SSTR)-directed imaging and therapy for neuroendocrine tumors (NET) is seeing rapidly increasing use. To maximize the full potential of its theranostic promise, efforts in recent years have expanded recommendations in current guidelines and included the evaluation of novel theranostic radiotracers for imaging and treatment of NET. Moreover, the introduction of standardized reporting framework systems may harmonize PET reading, address pitfalls in interpreting SSTR-PET/CT scans and guide the treating physician in selecting PRRT candidates. Notably, the concept of PRRT has also been applied beyond oncology, e.g. for treatment of inflammatory conditions like sarcoidosis. Future perspectives may include the efficacy evaluation of PRRT compared to other common treatment options for NET, novel strategies for closer monitoring of potential side effects, the introduction of novel radiotracers with beneficial pharmacodynamic and kinetic properties or the use of supervised machine learning approaches for outcome prediction. This article reviews how the SSTR-directed theranostic concept is currently applied and also reflects on recent developments that hold promise for the future of theranostics in this context.
KW  - theranostics
KW  - Positronen-Emissions-Tomografie
KW  - PRRT
KW  - somatostatin receptor
KW  - peptide receptor radionuclide therapy
KW  - neuroendocrine tumor
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170264
VL  - 8
IS  - 22
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Lückerath, Katharina
A1  - Kleinlein, Irene
A1  - Monoranu, Camelia Maria
A1  - Linsenmann, Thomas
A1  - Kessler, Almuth F.
A1  - Rudelius, Martina
A1  - Kropf, Saskia
A1  - Buck, Andreas K.
A1  - Ernestus, Ralf-Ingo
A1  - Wester, Hans-Jürgen
A1  - Löhr, Mario
A1  - Herrmann, Ken
T1  - \(^{68}\)Ga-Pentixafor-PET/CT for Imaging of Chemokine Receptor 4 Expression in Glioblastoma
JF  - Theranostics
N2  - Chemokine receptor-4 (CXCR4) has been reported to be overexpressed in glioblastoma (GBM) and to be associated with poor survival. This study investigated the feasibility of non-invasive CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using the radiolabelled chemokine receptor ligand \(^{68}\)Ga-Pentixafor.
15 patients with clinical suspicion on primary or recurrent glioblastoma (13 primary, 2 recurrent tumors) underwent \(^{68}\)Ga-Pentixafor-PET/CT for assessment of CXCR4 expression prior to surgery. O-(2-\(^{18}\)F-fluoroethyl)-L-tyrosine (\(^{18}\)F-FET) PET/CT images were available in 11/15 cases and were compared visually and semi-quantitatively (SUV\(_{max}\), SUV\(_{mean}\)). Tumor-to-background ratios (TBR) were calculated for both PET probes. \(^{68}\)Ga-Pentixafor-PET/CT results were also compared to histological CXCR4 expression on neuronavigated surgical samples.
\(^{68}\)Ga-Pentixafor-PET/CT was visually positive in 13/15 cases with SUV\(_{mean}\) and SUV\(_{max}\) of 3.0±1.5 and 3.9±2.0 respectively. Respective values for \(^{18}\)F-FET were 4.4±2.0 (SUV\(_{mean}\)) and 5.3±2.3 (SUV\(_{max}\)). TBR for SUV\(_{mean}\) and SUV\(_{max}\) were higher for \(^{68}\)Ga-Pentixafor than for \(^{18}\)F-FET (SUV\(_{mean}\) 154.0±90.7 vs. 4.1±1.3; SUV\(_{max}\) 70.3±44.0 and 3.8±1.2, p<0.01), respectively. Histological analysis confirmed CXCR4 expression in tumor areas with high \(^{68}\)Ga-Pentixafor uptake; regions of the same tumor without apparent \(^{68}\)Ga-Pentixafor uptake showed no or low receptor expression.
In this pilot study, \(^{68}\)Ga-Pentixafor retention has been observed in the vast majority of glioblastoma lesions and served as readout for non-invasive determination of CXCR4 expression. Given the paramount importance of the CXCR4/SDF-1 axis in tumor biology, \(^{68}\)Ga-Pentixafor-PET/CT might prove a useful tool for sensitive, non-invasive in-vivo quantification of CXCR4 as well as selection of patients who might benefit from CXCR4-directed therapy.
KW  - imaging
KW  - chemokine receptor-4
KW  - glioblastoma
KW  - positron emission tomography/computed tomography
KW  - \(^{68}\)Ga-Pentixafor
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168174
VL  - 6
IS  - 3
ER  - 
TY  - JOUR
A1  - Fecher, David
A1  - Hofmann, Elisabeth
A1  - Buck, Andreas
A1  - Bundschuh, Ralph
A1  - Nietzer, Sarah
A1  - Dandekar, Gudrun
A1  - Walles, Thorsten
A1  - Walles, Heike
A1  - Lückerath, Katharina
A1  - Steinke, Maria
T1  - Human Organotypic Lung Tumor Models: Suitable For Preclinical \(^{18}\)F-FDG PET-Imaging
JF  - PLoS ONE
N2  - Development of predictable in vitro tumor models is a challenging task due to the enormous complexity of tumors in vivo. The closer the resemblance of these models to human tumor characteristics, the more suitable they are for drug-development and –testing. In the present study, we generated a complex 3D lung tumor test system based on acellular rat lungs. A decellularization protocol was established preserving the architecture, important ECM components and the basement membrane of the lung. Human lung tumor cells cultured on the scaffold formed cluster and exhibited an up-regulation of the carcinoma-associated marker mucin1 as well as a reduced proliferation rate compared to respective 2D culture. Additionally, employing functional imaging with 2-deoxy-2-[\(^{18}\)F]fluoro-D-glucose positron emission tomography (FDG-PET) these tumor cell cluster could be detected and tracked over time. This approach allowed monitoring of a targeted tyrosine kinase inhibitor treatment in the in vitro lung tumor model non-destructively. Surprisingly, FDG-PET assessment of single tumor cell cluster on the same scaffold exhibited differences in their response to therapy, indicating heterogeneity in the lung tumor model. In conclusion, our complex lung tumor test system features important characteristics of tumors and its microenvironment and allows monitoring of tumor growth and -metabolism in combination with functional imaging. In longitudinal studies, new therapeutic approaches and their long-term effects can be evaluated to adapt treatment regimes in future.
KW  - lung and intrathoracic tumors
KW  - trachea
KW  - adenocarcinoma of the lung
KW  - cancer treatment
KW  - secondary lung tumors
KW  - pulmonary imaging
KW  - extracellular matrix
KW  - collagens
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-179678
VL  - 11
IS  - 8
ER  - 
TY  - JOUR
A1  - Morales-Lozano, Maria I.
A1  - Viering, Oliver
A1  - Samnick, Samuel
A1  - Rodriguez-Otero, Paula
A1  - Buck, Andreas K.
A1  - Marcos-Jubilar, Maria
A1  - Rasche, Leo
A1  - Prieto, Elena
A1  - Kortüm, K. Martin
A1  - San-Miguel, Jesus
A1  - Garcia-Velloso, Maria J.
A1  - Lapa, Constantin
T1  - \(^{18}\)F-FDG and \(^{11}\)C-methionine PET/CT in newly diagnosed multiple myeloma patients: comparison of volume-based PET biomarkers
JF  - Cancers
N2  - \(^{11}\)C-methionine (\(^{11}\)C-MET) is a new positron emission tomography (PET) tracer for the assessment of disease activity in multiple myeloma (MM) patients, with preliminary data suggesting higher sensitivity and specificity than \(^{18}\)F-fluorodeoxyglucose (\(^{18}\)F-FDG). However, the value of tumor burden biomarkers has yet to be investigated. Our goals were to corroborate the superiority of \(^{11}\)C-MET for MM staging and to compare its suitability for the assessment of metabolic tumor burden biomarkers in comparison to \(^{18}\)F-FDG. Twenty-two patients with newly diagnosed, treatment-naïve symptomatic MM who had undergone \(^{11}\)C-MET and \(^{18}\)F-FDG PET/CT were evaluated. Standardized uptake values (SUV) were determined and compared with total metabolic tumor volume (TMTV) for both tracers: total lesion glycolysis (TLG) and total lesion \(^{11}\)C-MET uptake (TLMU). PET-derived values were compared to Revised International Staging System (R-ISS), cytogenetic, and serologic MM markers such as M component, beta 2 microglobulin (B2M), serum free light chains (FLC), albumin, and lactate dehydrogenase (LDH). In 11 patients (50%), \(^{11}\)C-MET detected more focal lesions (FL) than FDG (p < 0.01). SUVmax, SUVmean, SUVpeak, TMTV, and TLMU were also significantly higher in \(^{11}\)C-MET than in \(^{18}\)F-FDG (p < 0.05, respectively). \(^{11}\)C-MET PET biomarkers had a better correlation with tumor burden (bone marrow plasma cell infiltration, M component; p < 0.05 versus p = n.s. respectively). This pilot study suggests that \(^{11}\)C-MET PET/CT is a more sensitive marker for the assessment of myeloma tumor burden than \(^{18}\)F-FDG. Its implications for prognosis evaluation need further investigation.
KW  - multiple myeloma
KW  - methionine
KW  - total lesion glycolysis (TLG)
KW  - metabolic tumor volume (MTV)
KW  - total lesion methionine uptake (TLMU)
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203686
SN  - 2072-6694
VL  - 12
IS  - 4
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Derlin, Thorsten
A1  - Lapa, Constantin
A1  - Sheikbahaei, Sara
A1  - Higuchi, Takahiro
A1  - Giesel, Frederik L.
A1  - Behr, Spencer
A1  - Drzezga, Alexander
A1  - Kimura, Hiroyuki
A1  - Buck, Andreas K.
A1  - Bengel, Frank M.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Rowe, Steven P.
T1  - \(^{18}\)F-labeled, PSMA-targeted radiotracers: leveraging the advantages of radiofluorination for prostate cancer molecular imaging
JF  - Theranostics
N2  - Prostate-specific membrane antigen (PSMA)-targeted PET imaging for prostate cancer with \(^{68}\)Ga-labeled compounds has rapidly become adopted as part of routine clinical care in many parts of the world. However, recent years have witnessed the start of a shift from \(^{68}\)Ga- to \(^{18}\)F-labeled PSMA-targeted compounds. The latter imaging agents have several key advantages, which may lay the groundwork for an even more widespread adoption into the clinic. First, facilitated delivery from distant suppliers expands the availability of PET radiopharmaceuticals in smaller hospitals operating a PET center but lacking the patient volume to justify an onsite \(^{68}\)Ge/\(^{68}\)Ga generator. Thus, such an approach meets the increasing demand for PSMA-targeted PET imaging in areas with lower population density and may even lead to cost-savings compared to in-house production. Moreover, \(^{18}\)F-labeled radiotracers have a higher positron yield and lower positron energy, which in turn decreases image noise, improves contrast resolution, and maximizes the likelihood of detecting subtle lesions. In addition, the longer half-life of 110 min allows for improved delayed imaging protocols and flexibility in study design, which may further increase diagnostic accuracy. Moreover, such compounds can be distributed to sites which are not allowed to produce radiotracers on-site due to regulatory issues or to centers without access to a cyclotron. In light of these advantageous characteristics, \(^{18}\)F-labeled PSMA-targeted PET radiotracers may play an important role in both optimizing this transformative imaging modality and making it widely available. We have aimed to provide a concise overview of emerging \(^{18}\)F-labeled PSMA-targeted radiotracers undergoing active clinical development. Given the wide array of available radiotracers, comparative studies are needed to firmly establish the role of the available \(^{18}\)F-labeled compounds in the field of molecular PCa imaging, preferably in different clinical scenarios.
KW  - Radiofluorine
KW  - prostate-specific membrane antigen
KW  - prostate cancer
KW  - \(^{18}\)F
KW  - PSMA
KW  - \(^{68}\)Ga
KW  - theranostics
KW  - radioligand therapy
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202559
SN  - 1838-7640
VL  - 10
IS  - 1
ER  - 
TY  - JOUR
A1  - Lapa, Constantin
A1  - Garcia-Velloso, Maria J.
A1  - Lückerath, Katharina
A1  - Samnick, Samuel
A1  - Schreder, Martin
A1  - Otero, Paula Rodriguez
A1  - Schmid, Jan-Stefan
A1  - Herrmann, Ken
A1  - Knop, Stefan
A1  - Buck, Andreas K.
A1  - Einsele, Hermann
A1  - San-Miguel, Jesus
A1  - Kortüm, Klaus Martin
T1  - \(^{11}\)C-methionine-PET in multiple myeloma: a combined study from two different institutions
JF  - Theranostics
N2  - \(^{11}\)C-methionine (MET) has recently emerged as an accurate marker of tumor burden and disease activity in patients with multiple myeloma (MM). This dual-center study aimed at further corroboration of the superiority of MET as positron emission tomography (PET) tracer for staging and re-staging MM, as compared to \(^{18}\)F-2`-deoxy-2`-fluoro-D-glucose (FDG).
78 patients with a history of solitary plasmacytoma (n=4), smoldering MM (SMM, n=5), and symptomatic MM (n=69) underwent both MET- and FDG-PET/computed tomography (CT) at the University Centers of Würzburg, Germany and Navarra, Spain. Scans were compared on a patient and on a lesion basis. Inter-reader agreement was also evaluated. In 2 patients, tumor biopsies for verification of discordant imaging results were available.
MET-PET detected focal lesions (FL) in 59/78 subjects (75.6%), whereas FDG-PET/CT showed lesions in only 47 patients (60.3%; p<0.01), accordingly disease activity would have been missed in 12 patients. Directed biopsies of discordant results confirmed MET-PET/CT results in both cases.
MET depicted more FL in 44 patients (56.4%; p<0.01), whereas in two patients (2/78), FDG proved superior. In the remainder (41.0%, 32/78), both tracers yielded comparable results. Inter-reader agreement for MET was higher than for FDG (κ = 0.82 vs κ = 0.72).
This study demonstrates higher sensitivity of MET in comparison to standard FDG to detect intra- and extramedullary MM including histologic evidence of FDG-negative, viable disease exclusively detectable by MET-PET/CT. MET holds the potential to replace FDG as functional imaging standard for staging and re-staging of MM.
KW  - medicine
KW  - PET/CT
KW  - \(^{11}\)C-methionine
KW  - multiple myeloma
KW  - FDG
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172038
VL  - 7
IS  - 11
ER  - 
TY  - JOUR
A1  - Mihatsch, Patrick W.
A1  - Beissert, Matthias
A1  - Pomper, Martin G.
A1  - Bley, Thorsten A.
A1  - Seitz, Anna K.
A1  - Kübler, Hubert
A1  - Buck, Andreas K.
A1  - Rowe, Steven P.
A1  - Serfling, Sebastian E.
A1  - Hartrampf, Philipp E.
A1  - Werner, Rudolf A.
T1  - Changing threshold-based segmentation has no relevant impact on semi-quantification in the context of structured reporting for PSMA-PET/CT
JF  - Cancers
N2  - Prostate-specific membrane antigen (PSMA)-directed positron emission tomography/computed tomography (PET/CT) is increasingly utilized for staging of men with prostate cancer (PC). To increase interpretive certainty, the standardized PSMA reporting and data system (RADS) has been proposed. Using PSMA-RADS, we characterized lesions in 18 patients imaged with \(^{18}\)F-PSMA-1007 PET/CT for primary staging and determined the stability of semi-quantitative parameters. Six hundred twenty-three lesions were categorized according to PSMA-RADS and manually segmented. In this context, PSMA-RADS-3A (soft-tissue) or -3B (bone) lesions are defined as being indeterminate for the presence of PC. For PMSA-RADS-4 and -5 lesions; however, PC is highly likely or almost certainly present [with further distinction based on absence (PSMA-RADS-4) or presence (PSMA-RADS-5) of correlative findings on CT]. Standardized uptake values (SUV\(_{max}\), SUV\(_{peak}\), SUV\(_{mean}\)) were recorded, and volumetric parameters [PSMA-derived tumor volume (PSMA-TV); total lesion PSMA (TL-PSMA)] were determined using different maximum intensity thresholds (MIT) (40 vs. 45 vs. 50%). SUV\(_{max}\) was significantly higher in PSMA-RADS-5 lesions compared to all other PSMA-RADS categories (p ≤ 0.0322). In particular, the clinically challenging PSMA-RADS-3A lesions showed significantly lower SUV\(_{max}\) and SUV\(_{peak}\) compared to the entire PSMA-RADS-4 or -5 cohort (p < 0.0001), while for PSMA-RADS-3B this only applies when compared to the entire PSMA-RADS-5 cohort (p < 0.0001), but not to the PSMA-RADS-4 cohort (SUV\(_{max}\), p = 0.07; SUV\(_{peak}\), p = 0.08). SUV\(_{mean}\) (p = 0.30) and TL-PSMA (p = 0.16) in PSMA-RADS-5 lesions were not influenced by changing the MIT, while PSMA-TV showed significant differences when comparing 40 vs. 50% MIT (p = 0.0066), which was driven by lymph nodes (p = 0.0239), but not bone lesions (p = 0.15). SUV\(_{max}\) was significantly higher in PSMA-RADS-5 lesions compared to all other PSMA-RADS categories in \(^{18}\)F-PSMA-1007 PET/CT. As such, the latter parameter may assist the interpreting molecular imaging specialist in assigning the correct PSMA-RADS score to sites of disease, thereby increasing diagnostic certainty. In addition, changes of the MIT in PSMA-RADS-5 lesions had no significant impact on SUV\(_{mean}\) and TL-PSMA in contrast to PSMA-TV.
KW  - \(^{18}\)F-PSMA-1007
KW  - PET/CT
KW  - staging
KW  - prostate cancer
KW  - standardized reporting system
KW  - PSMA-RADS
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-254782
SN  - 2072-6694
VL  - 14
IS  - 2
ER  - 
TY  - JOUR
A1  - Fröhlich, Matthias
A1  - Serfling, Sebastian
A1  - Higuchi, Takahiro
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Schmalzing, Marc
A1  - Tony, Hans-Peter
A1  - Gernert, Michael
A1  - Strunz, Patrick-Pascal
A1  - Portegys, Jan
A1  - Schwaneck, Eva-Christina
A1  - Gadeholt, Ottar
A1  - Weich, Alexander
A1  - Buck, Andreas K.
A1  - Bley, Thorsten A.
A1  - Guggenberger, Konstanze V.
A1  - Werner, Rudolf A.
T1  - Whole-Body [\(^{18}\)F]FDG PET/CT Can Alter Diagnosis in Patients with Suspected Rheumatic Disease
JF  - Diagnostics
N2  - The 2-deoxy-d-[\(^{18}\)F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) is widely utilized to assess the vascular and articular inflammatory burden of patients with a suspected diagnosis of rheumatic disease. We aimed to elucidate the impact of [\(^{18}\)F]FDG PET/CT on change in initially suspected diagnosis in patients at the time of the scan. Thirty-four patients, who had undergone [\(^{18}\)F]FDG PET/CT, were enrolled and the initially suspected diagnosis prior to [18F]FDG PET/CT was compared to the final diagnosis. In addition, a semi-quantitative analysis including vessel wall-to-liver (VLR) and joint-to-liver (JLR) ratios was also conducted. Prior to [\(^{18}\)F]FDG PET/CT, 22/34 (64.7%) of patients did not have an established diagnosis, whereas in 7/34 (20.6%), polymyalgia rheumatica (PMR) was suspected, and in 5/34 (14.7%), giant cell arteritis (GCA) was suspected by the referring rheumatologists. After [\(^{18}\)F]FDG PET/CT, the diagnosis was GCA in 19/34 (55.9%), combined GCA and PMR (GCA + PMR) in 9/34 (26.5%) and PMR in the remaining 6/34 (17.6%). As such, [\(^{18}\)F]FDG PET/CT altered suspected diagnosis in 28/34 (82.4%), including in all unclear cases. VLR of patients whose final diagnosis was GCA tended to be significantly higher when compared to VLR in PMR (GCA, 1.01 ± 0.08 (95%CI, 0.95–1.1) vs. PMR, 0.92 ± 0.1 (95%CI, 0.85–0.99), p = 0.07), but not when compared to PMR + GCA (1.04 ± 0.14 (95%CI, 0.95–1.13), p = 1). JLR of individuals finally diagnosed with PMR (0.94 ± 0.16, (95%CI, 0.83–1.06)), however, was significantly increased relative to JLR in GCA (0.58 ± 0.04 (95%CI, 0.55–0.61)) and GCA + PMR (0.64 ± 0.09 (95%CI, 0.57–0.71); p < 0.0001, respectively). In individuals with a suspected diagnosis of rheumatic disease, an inflammatory-directed [\(^{18}\)F]FDG PET/CT can alter diagnosis in the majority of the cases, particularly in subjects who were referred because of diagnostic uncertainty. Semi-quantitative assessment may be helpful in establishing a final diagnosis of PMR, supporting the notion that a quantitative whole-body read-out may be useful in unclear cases.
KW  - giant cell arteritis
KW  - GCA
KW  - [18F]FDG PET/CT
KW  - vasculature
KW  - inflammation
KW  - polymyalgia rheumatica
KW  - PMR
KW  - vasculitis
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250227
SN  - 2075-4418
VL  - 11
IS  - 11
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Krebs, Markus
A1  - Peter, Lea
A1  - Heinrich, Marieke
A1  - Ruffing, Julia
A1  - Kalogirou, Charis
A1  - Weinke, Maximilian
A1  - Brumberg, Joachim
A1  - Kübler, Hubert
A1  - Buck, Andreas K.
A1  - Werner, Rudolf A.
A1  - Seitz, Anna Katharina
T1  - Reduced segmentation of lesions is comparable to whole-body segmentation for response assessment by PSMA PET/CT: initial experience with the keyhole approach
JF  - Biology
N2  - Simple Summary
The calculation of PSMA-positive tumor volume (PSMA-TV) of the whole body from PSMA PET scans for response evaluation remains a time-consuming procedure. We hypothesized that it may be possible to quantify changes in PSMA-TV by considering only a limited number of representative tumor lesions. Changes in the whole-body PSMA-TV of 65 patients were comparable to the changes in PSMA-TV after including only the ten largest lesions. Moreover, changes in PSMA-TV correlated well with changes in PSA levels, as did the changes in PSMA-TV with the reduced number of lesions. We conclude that a response assessment using PSMA-TV with a reduced number of lesions is feasible and could lead to a simplified process for evaluating PSMA PET/CT.
        
        
Abstract
(1) Background: Prostate-specific membrane antigen (PSMA) positron emission tomography (PET)-derived parameters, such as the commonly used standardized uptake value (SUV) and PSMA-positive tumor volume (PSMA-TV), have been proposed for response assessment in metastatic prostate cancer (PCa) patients. However, the calculation of whole-body PSMA-TV remains a time-consuming procedure. We hypothesized that it may be possible to quantify changes in PSMA-TV by considering only a limited number of representative lesions. (2) Methods: Sixty-five patients classified into different disease stages were assessed by PSMA PET/CT for staging and restaging after therapy. Whole-body PSMA-TV and whole-body SUV\(_{max}\) were calculated. We then repeated this calculation only including the five or ten hottest or largest lesions. The corresponding serum levels of prostate-specific antigen (PSA) were also determined. The derived delta between baseline and follow-up values provided the following parameters: ΔSUV\(_{maxall}\), ΔSUV\(_{max10}\), ΔSUV\(_{max5}\), ΔPSMA-TV\(_{all}\), ΔPSMA-TV\(_{10}\), ΔPSMA-TV\(_{5}\), ΔPSA. Finally, we compared the findings from our whole-body segmentation with the results from our keyhole approach (focusing on a limited number of lesions) and correlated all values with the biochemical response (ΔPSA). (3) Results: Among patients with metastatic hormone-sensitive PCa (mHSPC), none showed a relevant deviation for ΔSUV\(_{max10}\)/ΔSUV\(_{max5}\) or ΔPSMA-TV\(_{10}\)/ΔPSMA-TV\(_{5}\) compared to ΔSUV\(_{maxall}\) and ΔPSMA-TV\(_{all}\). For patients treated with taxanes, up to 6/21 (28.6%) showed clinically relevant deviations between ΔSUV\(_{maxall}\) and ΔSUV\(_{max10}\) or ΔSUV\(_{max5}\), but only up to 2/21 (9.5%) patients showed clinically relevant deviations between ΔPSMA-TV\(_{all}\) and ΔPSMA-TV\(_{10}\) or ΔPSMA-TV\(_{5}\). For patients treated with radioligand therapy (RLT), up to 5/28 (17.9%) showed clinically relevant deviations between ΔSUV\(_{maxall}\) and ΔSUV\(_{max10}\) or ΔSUV\(_{max5}\), but only 1/28 (3.6%) patients showed clinically relevant deviations between ΔPSMA-TV\(_{all}\) and ΔPSMA-TV\(_{10}\) or ΔPSMA-TV\(_{5}\). The highest correlations with ΔPSA were found for ΔPSMA-TV\(_{all}\) (r ≥ 0.59, p ≤ 0.01), followed by ΔPSMA-TV\(_{10}\) (r ≥ 0.57, p ≤ 0.01) and ΔPSMA-TV\(_{5}\) (r ≥ 0.53, p ≤ 0.02) in all cohorts. ΔPSA only correlated with ΔSUV\(_{maxall}\) (r = 0.60, p = 0.02) and with ΔSUV\(_{max10}\) (r = 0.53, p = 0.03) in the mHSPC cohort, as well as with ΔSUV\(_{maxall}\) (r = 0.51, p = 0.01) in the RLT cohort. (4) Conclusion: Response assessment using PSMA-TV with a reduced number of lesions is feasible, and may allow for a simplified evaluation process for PSMA PET/CT.
KW  - PET/CT
KW  - PSMA-TV
KW  - SUV
KW  - prostate cancer
KW  - taxane
KW  - radioligand therapy
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-271191
SN  - 2079-7737
VL  - 11
IS  - 5
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Marcus, Charles
A1  - Sheikhbahaei, Sara
A1  - Solnes, Lilja B.
A1  - Leal, Jeffrey P.
A1  - Du, Yong
A1  - Rowe, Steven P.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Javadi, Mehrbod S.
T1  - Visual and Semiquantitative Accuracy in Clinical Baseline 123I-Ioflupane SPECT/CT Imaging
JF  - Clinical Nuclear Medicine
N2  - PURPOSE:
We aimed to (a) elucidate the concordance of visual assessment of an initial I-ioflupane scan by a human interpreter with comparison to results using a fully automatic semiquantitative method and (b) to assess the accuracy compared to follow-up (f/u) diagnosis established by movement disorder specialists.

METHODS:
An initial I-ioflupane scan was performed in 382 patients with clinically uncertain Parkinsonian syndrome. An experienced reader performed a visual evaluation of all scans independently. The findings of the visual read were compared with semiquantitative evaluation. In addition, available f/u clinical diagnosis (serving as a reference standard) was compared with results of the human read and the software.

RESULTS:
When comparing the semiquantitative method with the visual assessment, discordance could be found in 25 (6.5%) of 382 of the cases for the experienced reader (ĸ = 0.868). The human observer indicated region of interest misalignment as the main reason for discordance. With neurology f/u serving as reference, the results of the reader revealed a slightly higher accuracy rate (87.7%, ĸ = 0.75) compared to semiquantification (86.2%, ĸ = 0.719, P < 0.001, respectively). No significant difference in the diagnostic performance of the visual read versus software-based assessment was found.

CONCLUSIONS:
In comparison with a fully automatic semiquantitative method in I-ioflupane interpretation, human assessment obtained an almost perfect agreement rate. However, compared to clinical established diagnosis serving as a reference, visual read seemed to be slightly more accurate as a solely software-based quantitative assessment.
KW  - Single-Photon-Emissions-Computertomographie
KW  - SPECT
KW  - Parkinson’s disease
KW  - Parkinsonism
KW  - DaTscan
KW  - 123I-Ioflupane
KW  - SPECT
KW  - SPECT/CT
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168181
SN  - 1536-0229
VL  - 44
IS  - 1
ER  - 
TY  - JOUR
A1  - Zhou, Xiang
A1  - Dierks, Alexander
A1  - Kertels, Olivia
A1  - Samnick, Samuel
A1  - Kircher, Malte
A1  - Buck, Andreas K.
A1  - Haertle, Larissa
A1  - Knorz, Sebastian
A1  - Böckle, David
A1  - Scheller, Lukas
A1  - Messerschmidt, Janin
A1  - Barakat, Mohammad
A1  - Truger, Marietta
A1  - Haferlach, Claudia
A1  - Einsele, Hermann
A1  - Rasche, Leo
A1  - Kortüm, K. Martin
A1  - Lapa, Constantin
T1  - The link between cytogenetics/genomics and imaging patterns of relapse and progression in patients with relapsed/refractory multiple myeloma: a pilot study utilizing 18F-FDG PET/CT
JF  - Cancers
N2  - Utilizing 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT), we performed this pilot study to evaluate the link between cytogenetic/genomic markers and imaging patterns in relapsed/refractory (RR) multiple myeloma (MM). We retrospectively analyzed data of 24 patients with RRMM who were treated at our institution between November 2018 and February 2020. At the last relapse/progression, patients had been treated with a median of three (range 1–10) lines of therapy. Six (25%) patients showed FDG avid extramedullary disease without adjacency to bone. We observed significantly higher maximum standardized uptake values (SUV\(_{max}\)) in patients harboring del(17p) compared with those without del(17p) (p = 0.025). Moreover, a high SUV\(_{max}\) of >15 indicated significantly shortened progression-free survival (PFS) (p = 0.01) and overall survival (OS) (p = 0.0002). One female patient exhibited biallelic TP53 alteration, i.e., deletion and mutation, in whom an extremely high SUV\(_{max}\) of 37.88 was observed. In summary, this pilot study suggested a link between del(17p)/TP53 alteration and high SUV\(_{max}\) on 18F-FDG PET/CT in RRMM patients. Further investigations are highly warranted at this point.
KW  - radiogenomics
KW  - 18F-FDG PET/CT
KW  - multiple myeloma
KW  - relapse
KW  - progression
KW  - pattern
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211157
SN  - 2072-6694
VL  - 12
IS  - 9
ER  - 
TY  - JOUR
A1  - Hoffmann, Jan V.
A1  - Janssen, Jan P.
A1  - Kanno, Takayuki
A1  - Shibutani, Takayuki
A1  - Onoguchi, Masahisa
A1  - Lapa, Constantin
A1  - Grunz, Jan-Peter
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
T1  - Performance evaluation of fifth-generation ultra-high-resolution SPECT system with two stationary detectors and multi-pinhole imaging
JF  - EJNMMI Physics
N2  - Background 
Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT\(^+\)). 

Methods 
The new U-SPECT5-E with two stationary detectors was used for acquiring data with \(^{99m}\)Tc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT\(^+\) for comparison. 

Results 
Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT\(^+\). In the visually analysed sections of the reconstructed mini Derenzo phantoms, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT\(^+\)) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60 to 1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR. 

Conclusions 
While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup.
KW  - small-animal imaging
KW  - SPECT
KW  - mouse
KW  - ollimator
KW  - post-reconstruction filtering
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230361
VL  - 7
ER  - 
TY  - JOUR
A1  - Janssen, Jan P.
A1  - Hoffmann, Jan V.
A1  - Kanno, Takayuki
A1  - Nose, Naoko
A1  - Grunz, Jan-Peter
A1  - Onoguchi, Masahisa
A1  - Chen, Xinyu
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Higuchi, Takahiro
T1  - Capabilities of multi-pinhole SPECT with two stationary detectors for in vivo rat imaging
JF  - Scientific Reports
N2  - We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available \(^{99m}\)Tc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with \(^{99m}\)Tc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with similar to 100 MBq [\(^{99m}\)TcTc-MIBI or similar to 150 MBq [\(^{99m}\)Tc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1="very poor" to 5="very good". Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.
KW  - small animal SPECT
KW  - HMDP hydroxymethylene diphosphonate
KW  - skeletal
KW  - quality
KW  - scanner
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230616
VL  - 10
ER  - 
TY  - JOUR
A1  - Werner, Rudolf
A1  - Hänscheid, Heribert
A1  - Leal, Jeffrey P.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Lodge, Martin A.
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
T1  - Impact of Tumor Burden on Quantitative [\(^{68}\)Ga]DOTATOC Biodistribution
JF  - Molecular Imaging and Biology
N2  - Purpose: As has been previously reported, the somatostatin receptor (SSTR) imaging agent [\(^{68}\)Ga]-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe(1)-Tyr(3)-octreotate ([\(^{68}\)Ga]DOTATATE) demonstrates lower uptake in normal organs in patients with a high neuroendocrine tumor (NET) burden. Given the higher SSTR affinity of [\(^{68}\)Ga]DOTATATE, we aimed to quantitatively investigate the biodistribution of [\(^{68}\)Ga]-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe(1)-Tyr(3)-octreotide ([68Ga]DOTATOC) to determine a potential correlation between uptake in normal organs and NET burden.
Procedures: Of the 44 included patients, 36/44 (82%) patients demonstrated suspicious radiotracer uptake on [\(^{68}\)Ga]DOTATOC positron emission tomography (PET)/x-ray computed tomography (CT). Volumes of Interest (VOIs) were defined for tumor lesions and normal organs (spleen, liver, kidneys, adrenals). Mean body weight corrected standardized uptake value (SUV\(_{mean}\)) for normal organs was assessed and was used to calculate the corresponding mean specific activity uptake (Upt: fraction of injected activity per kg of tissue). For the entire tumor burden, SUV\(_{mean}\), maximum standardized uptake value (SUV\(_{max}\)), and the total mass (TBM) was calculated and the decay corrected tumor fractional uptake (TBU) was assessed. A Spearman’s rank correlation coefficient was used to determine the correlations between normal organ uptake and tumor burden. 
Results: The median SUV\(_{mean}\) was 18.7 for the spleen (kidneys, 9.2; adrenals, 6.8; liver, 5.6). For tumor burden, the median values were SUV\(_{mean}\) 6.9, SUV\(_{max}\) 35.5, TBM 42.6g, and TBU 1.2%. With increasing volume of distribution, represented by lean body mass and body surface area (BSA), Upt decreased in kidneys, liver, and adrenal glands and SUV\(_{mean}\) increased in the spleen. Correlation improved only for both kidneys and adrenals when the influence of the tumor uptake on the activity available for organ uptake was taken into account by the factor 1/(1-TBU). TBU was neither predictive for SUV\(_{mean}\) nor for Upt in any of the organs. The distribution of organ Upt vs. BSA/(1-TBU) were not different for patients with minor TBU (<3%) vs. higher TBU (>7%), indicating that the correlations observed in the present study are explainable by the body size effect. High tumor mass and uptake mitigated against G1 NET. 
Conclusions: There is no significant impact on normal organ biodistribution with increasing tumor burden on [\(^{68}\)Ga]DOTATOC PET/CT. Potential implications include increased normal organ dose with [\(^{177}\)Lu-DOTA]\(^0\)-D-Phe\(^1\)-Tyr\(^3\)-Octreotide and decreased absolute lesion detection with [\(^{68}\)Ga]DOTATOC in high NET burden.
KW  - somatostatin receptor
KW  - Positronen-Emissions-Tomografie
KW  - quantification
KW  - [68Ga]DOTATOC
KW  - neuroendocrine tumor
KW  - SSTR-PET
KW  - theranostics
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170280
ER  - 
TY  - JOUR
A1  - Tamihardja, Jörg
A1  - Zehner, Leonie
A1  - Hartrampf, Philipp E.
A1  - Cirsi, Sinan
A1  - Wegener, Sonja
A1  - Buck, Andreas K.
A1  - Flentje, Michael
A1  - Polat, Bülent
T1  - Dose-escalated salvage radiotherapy for macroscopic local recurrence of prostate cancer in the prostate-specific membrane antigen positron emission tomography era
JF  - Cancers
N2  - Simple Summary
Prostate cancer often relapses after initial radical prostatectomy, and salvage radiotherapy offers a second chance of cure for relapsed patients. Modern imaging techniques, especially prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT), enable radiation oncologists to target radiotherapy at the involved sites of disease. In a group of patients, PSMA PET/CT imaging can detect a macroscopic local recurrence with or without locoregional lymph node metastasis. In these cases, an escalation of the radiotherapy dose is often considered for controlling the visible tumor mass. As the evidence for dose-escalated salvage radiotherapy for macroscopic recurrent prostate cancer after PSMA PET/CT imaging is still limited, we address this topic in the current analysis. We found that the outcome of patients with dose-escalated salvage radiotherapy for macroscopic prostate cancer recurrence is encouragingly favorable, while the toxicity is very limited.  
        
Abstract
Background: The purpose of this study was to access the oncological outcome of prostate-specific membrane antigen positron emission tomography (PSMA PET/CT)-guided salvage radiotherapy (SRT) for localized macroscopic prostate cancer recurrence. Methods: Between February 2010 and June 2021, 367 patients received SRT after radical prostatectomy. Out of the 367 screened patients, 111 patients were staged by PSMA PET/CT before SRT. A total of 59 out of these 111 (53.2%) patients were treated for PSMA PET-positive macroscopic prostatic fossa recurrence. Dose-escalated SRT was applied with a simultaneous integrated boost at a median prescribed dose of 69.3 Gy (IQR 69.3–72.6 Gy). The oncological outcome was investigated using Kaplan-Meier and Cox regression analyses. The genitourinary (GU)/gastrointestinal (GI) toxicity evaluation utilized Common Toxicity Criteria for Adverse Events (version 5.0). Results: The median follow-up was 38.2 months. The three-year biochemical progression-free survival rate was 89.1% (95% CI: 81.1–97.8%) and the three-year metastasis-free survival rate reached 96.2% (95% CI: 91.2–100.0%). The cumulative three-year late grade 3 GU toxicity rate was 3.4%. No late grade 3 GI toxicity occurred. Conclusions: Dose-escalated PSMA PET/CT-guided salvage radiotherapy for macroscopic prostatic fossa recurrence resulted in favorable survival and toxicity rates.
KW  - prostate cancer
KW  - salvage radiotherapy
KW  - macroscopic recurrence
KW  - PSMA PET/CT
KW  - simultaneous integrated boost
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290302
SN  - 2072-6694
VL  - 14
IS  - 19
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Petritsch, Bernhard
A1  - Buck, Andreas K.
A1  - Serfling, Sebastian E.
T1  - Pitfalls in PSMA-PET/CT: Intensive bone-marrow uptake in a case with polycythaemia vera
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - No abstract available.
KW  - bone-marrow
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235608
SN  - 1619-7070
VL  - 48
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Habacha, Bilêl
A1  - Lütje, Susanne
A1  - Bundschuh, Lena
A1  - Higuchi, Takahiro
A1  - Hartrampf, Philipp
A1  - Serfling, Sebastian E.
A1  - Derlin, Thorsten
A1  - Lapa, Constantin
A1  - Buck, Andreas K.
A1  - Essler, Markus
A1  - Pienta, Kenneth J.
A1  - Eisenberger, Mario A.
A1  - Markowski, Mark C.
A1  - Shinehouse, Laura
A1  - AbdAllah, Rehab
A1  - Salavati, Ali
A1  - Lodge, Martin A.
A1  - Pomper, Martin G.
A1  - Gorin, Michael A.
A1  - Bundschuh, Ralph A.
A1  - Rowe, Steven P.
T1  - High SUVs Have More Robust Repeatability in Patients with Metastatic Prostate Cancer: Results from a Prospective Test-Retest Cohort Imaged with \(^{18}\)F-DCFPyL
JF  - Molecular Imaging
N2  - No abstract available.
KW  - SUV
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300748
VL  - 2022
ER  - 
TY  - JOUR
A1  - Chen, Xinyu
A1  - Kudo, Takashi
A1  - Lapa, Constantin
A1  - Buck, Andreas
A1  - Higuchi, Takahiro
T1  - Recent advances in radiotracers targeting norepinephrine transporter: structural development and radiolabeling improvements
JF  - Journal of Neural Transmission
N2  - The norepinephrine transporter (NET) is a major target for the evaluation of the cardiac sympathetic nerve system in patients with heart failure and Parkinson's disease. It is also used in the therapeutic applications against certain types of neuroendocrine tumors, as exemplified by the clinically used \(^{123/131}\)I-MIBG as theranostic single-photon emission computed tomography (SPECT) agent. With the development of more advanced positron emission tomography (PET) technology, more radiotracers targeting NET have been reported, with superior temporal and spatial resolutions, along with the possibility of functional and kinetic analysis. More recently, fluorine-18-labelled NET tracers have drawn increasing attentions from researchers, due to their longer radiological half-life relative to carbon-11 (110 min vs. 20 min), reduced dependence on on-site cyclotrons, and flexibility in the design of novel tracer structures. In the heart, certain NET tracers provide integral diagnostic information on sympathetic innervation and the nerve status. In the central nervous system, such radiotracers can reveal NET distribution and density in pathological conditions. Most radiotracers targeting cardiac NET-function for the cardiac application consistent of derivatives of either norepinephrine or MIBG with its benzylguanidine core structure, e.g. \(^{11}\)C-HED and \(^{18}\)F-LMI1195. In contrast, all NET tracers used in central nervous system applications are derived from clinically used antidepressants. Lastly, possible applications of NET as selective tracers over organic cation transporters (OCTs) in the kidneys and other organs controlled by sympathetic nervous system will also be discussed.
KW  - norepinephrine transporter
KW  - benzylguanidine
KW  - phenethylguanidine
KW  - antidepressant
KW  - organic cation transporter
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241148
VL  - 127
ER  - 
TY  - JOUR
A1  - Buck, Andreas
A1  - Decristoforo, Clemens
T1  - Highlights lecture EANM 2015: the search for nuclear medicine's superheroes
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - The EANM 2015 Annual Congress, held from October 10th to 14th in Hamburg, Germany, was outstanding in many respects. With 5550 participants, this was by far the largest European congress concerning nuclear medicine. More than 1750 scientific presentations were submitted, with more than 250 abstracts from young scientists, indicating that the future success of our discipline is fuelled by a high number of young individuals becoming involved in a multitude of scientific activities. Significant improvements have been made in molecular imaging of cancer, particularly in prostate cancer. PSMA-directed PET/CT appears to become a new gold standard for staging and restaging purposes. Novel tumour specific compounds have shown their potential for target identification also in other solid neoplasms and further our understanding of tumour biology and heterogeneity. In addition, a variety of nuclear imaging techniques guiding surgical interventions have been introduced. A particular focus of the congress was put on targeted, radionuclide based therapies. Novel theranostic concepts addressing also tumour entities with high incidence rates such as prostate cancer, melanoma, and lymphoma, have shown effective anti-tumour activity. Strategies have been presented to improve further already established therapeutic regimens such as somatostatin receptor based radio receptor therapy for treating advanced neuroendocrine tumours. Significant contributions were presented also in the neurosciences track. An increasing number of target structures of high interest in neurology and psychiatry are now available for PET and SPECT imaging, facilitating specific imaging of different subtypes of dementia and movement disorders as well as neuroinflammation. Major contributions in the cardiovascular track focused on further optimization of cardiac perfusion imaging by reducing radiation exposure, reducing scanning time, and improving motion correction. Besides coronary artery disease, many contributions focused on cardiac inflammation, cardiac sarcoidosis, and specific imaging of large vessel vasculitis. The physics and instrumentation track included many highlights such as novel, high resolution scanners. The most noteworthy news and developments of this meeting were summarized in the highlights lecture. Only 55 scientific contributions were mentioned, and hence they represent only a brief summary, which is outlined in this article. For a more detailed view, all presentations can be accessed by the online version of the European Journal of Nuclear Medicine and Molecular Imaging (Volume 42, Supplement 1).
KW  - Conjugate arc therapy
KW  - Phase-II
KW  - 18F-FDG PET/CT
KW  - Highlights Lecture
KW  - Molecular Imaging
KW  - Prostate-cancer
KW  - Radionuclide therapy
KW  - Myocardial perfusion
KW  - Preclinical evaluation
KW  - Targeted therapy
KW  - Thyroid cancer
KW  - SPECT
KW  - 2015
KW  - EANM
KW  - Hamburg
KW  - Physics and instrumentation
KW  - Radiopharmacy
KW  - Oncology
KW  - Radionuclide Therapy
KW  - Cardiology
KW  - Neurosciences
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-187613
VL  - 43
IS  - 10
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Lapa, Constantin
A1  - Serfling, Sebastian E.
A1  - Buck, Andreas K.
A1  - Seitz, Anna Katharina
A1  - Meyer, Philipp T.
A1  - Ruf, Juri
A1  - Michalski, Kerstin
T1  - Development of Discordant Hypermetabolic Prostate Cancer Lesions in the Course of [\(^{177}\)Lu]PSMA Radioligand Therapy and Their Possible Influence on Patient Outcome
JF  - Cancers
N2  - Simple Summary
Discordant FDG-positive but PSMA-negative (FDG+/PSMA−) metastases constitute a negative prognostic marker of overall survival in patients undergoing PSMA radioligand therapy (RLT). The aim of this analysis was to investigate the prognostic implications of new FDG+/PSMA− lesions, which occur during or after PSMA RLT. In a retrospective bicentric analysis of 32 patients undergoing PSMA RLT and follow-up dual tracer staging with PSMA and FDG PET/CT, FDG+/PSMA− lesions occurred in a limited number of patients. However, the presence of FDG+/PSMA− lesions appears not to have a significant impact on the OS, but further studies are needed to establish the clinical relevance of such lesions.

Abstract
Introduction: Positron emission tomography/computer tomography (PET/CT) targeting the prostate-specific membrane antigen (PSMA) is crucial for the assessment of adequate PSMA expression in patients with metastatic castration-resistant prostate cancer (mCRPC) prior to PSMA radioligand therapy (PSMA RLT). Moreover, initial dual tracer staging using combined PSMA and [\(^{18}\)F]fluorodeoxyglucose (FDG) PET/CT provides relevant information, since discordant FDG-positive but PSMA-negative (FDG+/PSMA−) lesions constitute a negative prognostic marker of overall survival (OS) after PSMA RLT. However, little is known about the prognostic implications of dual tracer imaging for restaging at follow-up. The aim of this analysis was to investigate the prognostic implications of new FDG+/PSMA− lesions during or after PSMA RLT. Methods: This bicentric analysis included 32 patients with mCRPC who underwent both FDG and PSMA PET/CT imaging after two or four cycles of PSMA RLT. Patients with FDG+/PSMA− lesions prior to PSMA RLT were not considered. The presence of FDG+/PSMA− lesions was assessed with follow-up dual tracer imaging of patients after two or four cycles of PSMA RLT. Patients with at least one new FDG+/PSMA− lesion were compared to patients without any FDG+/PSMA− lesions at the respective time points. A log-rank analysis was used to assess the difference in OS between subgroups. Results: After two cycles of PSMA RLT, four of 32 patients (13%) had FDG+/PSMA− metastases. No significant difference in OS was observed (p = 0.807), as compared to patients without FDG+/PSMA− lesions. Follow-up dual tracer imaging after the 4th cycle of PSMA RLT was available in 18 patients. Of these, four patients presented with FDG+/PSMA− findings (n = 2 already after two cycles). After the fourth cycle of PSMA RLT, no significant difference in OS was observed between patients with and without FDG+/PSMA− lesions (p = 0.442). Conclusion: This study shows that FDG+/PSMA− lesions develop in a limited number of patients undergoing PSMA RLT. Further studies are needed to establish the clinical relevance of such lesions.
KW  - PSMA
KW  - FDG
KW  - PET/CT
KW  - prostate cancer
KW  - radioligand therapy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-245168
SN  - 2072-6694
VL  - 13
IS  - 17
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Weinzierl, Franz-Xaver
A1  - Serfling, Sebastian E.
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
A1  - Higuchi, Takahiro
A1  - Seitz, Anna Katharina
A1  - Kübler, Hubert
A1  - Buck, Andreas K.
A1  - Werner, Rudolf A.
T1  - Hematotoxicity and nephrotoxicity in prostate cancer patients undergoing radioligand therapy with [\(^{177}\)Lu]Lu-PSMA I&T
JF  - Cancers
N2  - (1) Background: Prostate-specific membrane antigen (PSMA)-directed radioligand therapy (RLT) has shown remarkable results in patients with advanced prostate cancer. We aimed to evaluate the toxicity profile of the PSMA ligand [\(^{177}\)Lu]Lu-PSMA I&T. (2) Methods: 49 patients with metastatic, castration-resistant prostate cancer treated with at least three cycles of [\(^{177}\)Lu]Lu-PSMA I&T were evaluated. Prior to and after RLT, we compared leukocytes, hemoglobin, platelet counts, and renal functional parameters (creatinine, eGFR, n = 49; [\(^{99m}\)Tc]-MAG3-derived tubular extraction rate (TER), n = 42). Adverse events were classified according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 and KDIGO Society. To identify predictive factors, we used Spearman's rank correlation coefficient. (3) Results: A substantial fraction of the patients already showed impaired renal function and reduced leukocyte counts at baseline. Under RLT, 11/49 (22%) patients presented with nephrotoxicity CTCAE I or II according to creatinine, but 33/49 (67%) according to eGFR. Only 5/42 (13%) showed reduced TER, defined as <70% of the age-adjusted mean normal values. Of all renal functional parameters, absolute changes of only 2% were recorded. CTCAE-based re-categorization was infrequent, with creatinine worsening from I to II in 2/49 (4.1%; GFR, 1/49 (2%)). Similar results were recorded for KDIGO (G2 to G3a, 1/49 (2%); G3a to G3b, 2/49 (4.1%)). After three cycles, follow-up eGFR correlated negatively with age (r = −0.40, p = 0.005) and the eGFR change with Gleason score (r = −0.35, p < 0.05) at baseline. Leukocytopenia CTCAE II occurred only in 1/49 (2%) (CTCAE I, 20/49 (41%)) and CTCAE I thrombocytopenia in 7/49 (14%), with an absolute decrease of 15.2% and 16.6% for leukocyte and platelet counts. Anemia CTCAE II occurred in 10/49 (20%) (CTCAE I, 36/49 (73%)) with a decrease in hemoglobin of 4.7%. (4) Conclusions: After PSMA-targeted therapy using [\(^{177}\)Lu]Lu-PSMA I&T, no severe (CTCAE III/IV) toxicities occurred, thereby demonstrating that serious adverse renal or hematological events are unlikely to be a frequent phenomenon with this agent.
KW  - PSMA
KW  - radioligand therapy
KW  - RLT
KW  - \(^{177}\)Lu
KW  - nephrotoxicity
KW  - hematotoxicity
KW  - CTCAE
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-254825
SN  - 2072-6694
VL  - 14
IS  - 3
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Kuzkina, Anastasia
A1  - Lapa, Constantin
A1  - Mammadova, Sona
A1  - Buck, Andreas
A1  - Volkmann, Jens
A1  - Sommer, Claudia
A1  - Isaias, Ioannis U.
A1  - Doppler, Kathrin
T1  - Dermal and cardiac autonomic fiber involvement in Parkinson's disease and multiple system atrophy
JF  - Neurobiology of Disease
N2  - Pathological aggregates of alpha-synuclein in peripheral dermal nerve fibers can be detected in patients with idiopathic Parkinson's disease and multiple system atrophy. This study combines skin biopsy staining for p-alpha-synuclein depositions and radionuclide imaging of the heart with [\(^{123}\)I]-metaiodobenzylguanidine to explore peripheral denervation in both diseases. To this purpose, 42 patients with a clinical diagnosis of Parkinson's disease or multiple system atrophy were enrolled. All patients underwent a standardized clinical workup including neurological evaluation, neurography, and blood samples. Skin biopsies were obtained from the distal and proximal leg, back, and neck for immunofluorescence double labeling with anti-p-alpha-synuclein and anti-PGP9.5. All patients underwent myocardial [\(^{123}\)I]-metaiodobenzylguanidine scintigraphy. Dermal p-alpha-synuclein was observed in 47.6% of Parkinson's disease patients and was mainly found in autonomic structures. 81.0% of multiple system atrophy patients had deposits with most of cases in somatosensory fibers. The [\(^{123}\)I]-metaiodobenzylguanidine heart-to-mediastinum ratio was lower in Parkinson's disease than in multiple system atrophy patients (1.94 +/- 0.63 vs. 2.91 +/- 0.96; p < 0.0001). Irrespective of the diagnosis, uptake was lower in patients with than without p-alpha-synuclein in autonomic structures (1.42 +/- 0.51 vs. 2.74 +/- 0.83; p < 0.0001). Rare cases of Parkinson's disease with p-alpha-synuclein in somatosensory fibers and multiple system atrophy patients with deposits in autonomic structures or both fiber types presented with clinically overlapping features. In conclusion, this study suggests that alpha-synuclein contributes to peripheral neurodegeneration and mediates the impairment of cardiac sympathetic neurons in patients with synucleinopathies. Furthermore, it indicates that Parkinson's disease and multiple system atrophy share pathophysiologic mechanisms of peripheral nervous system dysfunction with a clinical overlap.
KW  - peripheral nervous system
KW  - Parkinson's disease
KW  - skin biopsy
KW  - MIBG scintigraphy
KW  - multiple system atrophy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260061
VL  - 153
ER  - 
TY  - JOUR
A1  - Marquardt, André
A1  - Hartrampf, Philipp
A1  - Kollmannsberger, Philip
A1  - Solimando, Antonio G.
A1  - Meierjohann, Svenja
A1  - Kübler, Hubert
A1  - Bargou, Ralf
A1  - Schilling, Bastian
A1  - Serfling, Sebastian E.
A1  - Buck, Andreas
A1  - Werner, Rudolf A.
A1  - Lapa, Constantin
A1  - Krebs, Markus
T1  - Predicting microenvironment in CXCR4- and FAP-positive solid tumors — a pan-cancer machine learning workflow for theranostic target structures
JF  - Cancers
N2  - (1) Background: C-X-C Motif Chemokine Receptor 4 (CXCR4) and Fibroblast Activation Protein Alpha (FAP) are promising theranostic targets. However, it is unclear whether CXCR4 and FAP positivity mark distinct microenvironments, especially in solid tumors. (2) Methods: Using Random Forest (RF) analysis, we searched for entity-independent mRNA and microRNA signatures related to CXCR4 and FAP overexpression in our pan-cancer cohort from The Cancer Genome Atlas (TCGA) database —  representing n = 9242 specimens from 29 tumor entities. CXCR4- and FAP-positive samples were assessed via StringDB cluster analysis, EnrichR, Metascape, and Gene Set Enrichment Analysis (GSEA). Findings were validated via correlation analyses in n = 1541 tumor samples. TIMER2.0 analyzed the association of CXCR4 / FAP expression and infiltration levels of immune-related cells. (3) Results: We identified entity-independent CXCR4 and FAP gene signatures representative for the majority of solid cancers. While CXCR4 positivity marked an immune-related microenvironment, FAP overexpression highlighted an angiogenesis-associated niche. TIMER2.0 analysis confirmed characteristic infiltration levels of CD8+ cells for CXCR4-positive tumors and endothelial cells for FAP-positive tumors. (4) Conclusions: CXCR4- and FAP-directed PET imaging could provide a non-invasive decision aid for entity-agnostic treatment of microenvironment in solid malignancies. Moreover, this machine learning workflow can easily be transferred towards other theranostic targets.
KW  - machine learning
KW  - tumor microenvironment
KW  - immune infiltration
KW  - angiogenesis
KW  - mRNA
KW  - miRNA
KW  - transcriptome
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-305036
SN  - 2072-6694
VL  - 15
IS  - 2
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Sayehli, Cyrus
A1  - Hänscheid, Heribert
A1  - Higuchi, Takahiro
A1  - Serfling, Sebastian E.
A1  - Fassnacht, Martin
A1  - Goebeler, Maria-Elisabeth
A1  - Buck, Andreas K.
A1  - Kroiss, Matthias
T1  - Successful combination of selpercatinib and radioiodine after pretherapeutic dose estimation in RET-altered thyroid carcinoma
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - No abstract available.
KW  - papillary thyroid carcinoma (PTC)
KW  - selpercatinib
KW  - radioiodine
KW  - combination
KW  - thyroid carcinoma (TC)
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324435
VL  - 50
IS  - 6
ER  - 
TY  - JOUR
A1  - Weich, Alexander
A1  - Higuchi, Takahiro
A1  - Bundschuh, Ralph A.
A1  - Lapa, Constantin
A1  - Serfling, Sebastian E.
A1  - Rowe, Steven P.
A1  - Pomper, Martin G.
A1  - Herrmann, Ken
A1  - Buck, Andreas K.
A1  - Derlin, Thorsten
A1  - Werner, Rudolf A.
T1  - Training on reporting and data system (RADS) for somatostatin-receptor targeted molecular imaging can reduce the test anxiety of inexperienced readers
JF  - Molecular Imaging and Biology
N2  - Purpose
For somatostatin receptor (SSTR)-positron emission tomography/computed tomography (PET/CT), a standardized framework termed SSTR-reporting and data system (RADS) has been proposed. We aimed to elucidate the impact of a RADS-focused training on reader’s anxiety to report on SSTR-PET/CT, the motivational beliefs in learning such a system, whether it increases reader’s confidence, and its implementation in clinical routine.

Procedures
A 3-day training course focusing on SSTR-RADS was conducted. Self-report questionnaires were handed out prior to the course (Pre) and thereafter (Post). The impact of the training on the following categories was evaluated: (1) test anxiety to report on SSTR-PET/CT, (2) motivational beliefs, (3) increase in reader’s confidence, and (4) clinical implementation. To assess the effect size of the course, Cohen’s d was calculated (small, d = 0.20; large effect, d = 0.80).

Results
Of 22 participants, Pre and Post were returned by 21/22 (95.5%). In total, 14/21 (66.7%) were considered inexperienced (IR, < 1 year experience in reading SSTR-PET/CTs) and 7/21 (33.3%) as experienced readers (ER, > 1 year). Applying SSTR-RADS, a large decrease in anxiety to report on SSTR-PET/CT was noted for IR (d =  − 0.74, P = 0.02), but not for ER (d = 0.11, P = 0.78). For the other three categories motivational beliefs, reader’s confidence, and clinical implementation, agreement rates were already high prior to the training and persisted throughout the course (P ≥ 0.21).

Conclusions
A framework-focused reader training can reduce anxiety to report on SSTR-PET/CTs, in particular for inexperienced readers. This may allow for a more widespread adoption of this system, e.g., in multicenter trials for better intra- and interindividual comparison of scan results.
KW  - PET/CT
KW  - neuroendocrine tumor
KW  - PRRT
KW  - peptide receptor radionuclide therapy
KW  - reporting and data system
KW  - SSTR-RADS
KW  - RADS
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324645
VL  - 24
IS  - 4
ER  - 
TY  - JOUR
A1  - Göring, Lukas
A1  - Schumann, Sarah
A1  - Müller, Jessica
A1  - Buck, Andreas K.
A1  - Port, Matthias
A1  - Lassmann, Michael
A1  - Scherthan, Harry
A1  - Eberlein, Uta
T1  - Repair of a-particle-induced DNA damage in peripheral blood mononuclear cells after internal ex vivo irradiation with \(^{223}\)Ra
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Purpose
As α-emitters for radiopharmaceutical therapies are administered systemically by intravenous injection, blood will be irradiated by α-particles that induce clustered DNA double-strand breaks (DSBs). Here, we investigated the induction and repair of DSB damage in peripheral blood mononuclear cells (PBMCs) as a function of the absorbed dose to the blood following internal ex vivo irradiation with [\(^{223}\)Ra]RaCl2.

Methods
Blood samples of ten volunteers were irradiated by adding [\(^{223}\)Ra]RaCl2 solution with different activity concentrations resulting in absorbed doses to the blood of 3 mGy, 25 mGy, 50 mGy and 100 mGy. PBMCs were isolated, divided in three parts and either fixed directly (d-samples) or after 4 h or 24 h culture. After immunostaining, the induced γ-H2AX α-tracks were counted. The time-dependent decrease in α-track frequency was described with a model assuming a repair rate R and a fraction of non-repairable damage Q.

Results
For 25 mGy, 50 mGy and 100 mGy, the numbers of α-tracks were significantly increased compared to baseline at all time points. Compared to the corresponding d-samples, the α-track frequency decreased significantly after 4 h and after 24 h. The repair rates R were (0.24 ± 0.05) h−1 for 25 mGy, (0.16 ± 0.04) h−1 for 50 mGy and (0.13 ± 0.02) h−1 for 100 mGy, suggesting faster repair at lower absorbed doses, while Q-values were similar.

Conclusion
The results obtained suggest that induction and repair of the DSB damage depend on the absorbed dose to the blood. Repair rates were similar to what has been observed for irradiation with low linear energy transfer.
KW  - DSB damage
KW  - irradiation
KW  - α-Particle
KW  - γ-H2AX
KW  - repair
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324557
VL  - 49
IS  - 12
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Bundschuh, Ralph A.
A1  - Weinzierl, Franz-Xaver
A1  - Serfling, Sebastian E.
A1  - Kosmala, Aleksander
A1  - Seitz, Anna Katharina
A1  - Kübler, Hubert
A1  - Buck, Andreas K.
A1  - Essler, Markus
A1  - Werner, Rudolf A.
T1  - mCRPC patients with PSA fluctuations under radioligand therapy have comparable survival benefits relative to patients with sustained PSA decrease
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Introduction
In men with metastatic castration-resistant prostate cancer (mCRPC) scheduled for prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT), biochemical response is assessed based on repeated measurements of prostate-specific antigen (PSA) levels. We aimed to determine overall survival (OS) in patients experiencing sustained PSA increase, decrease, or fluctuations during therapy.

Materials and methods
In this bicentric study, we included 176 mCRPC patients treated with PSMA-directed RLT. PSA levels were determined using blood samples prior to the first RLT and on the admission days for the following cycles. We calculated relative changes in PSA levels compared to baseline. Kaplan–Meier curves as well as log-rank test were used to compare OS of different subgroups, including patients with sustained PSA increase, decrease, or fluctuations (defined as change after initial decrease or increase after the first cycle).

Results
Sixty-one out of one hundred seventy-six (34.7%) patients showed a sustained increase and 86/176 (48.8%) a sustained decrease in PSA levels. PSA fluctuations were observed in the remaining 29/176 (16.5%). In this subgroup, 22/29 experienced initial PSA decrease followed by an increase (7/29, initial increase followed by a decrease). Median OS of patients with sustained decrease in PSA levels was significantly longer when compared to patients with sustained increase of PSA levels (19 vs. 8 months; HR 0.35, 95% CI 0.22–0.56; P < 0.001). Patients with PSA fluctuations showed a significantly longer median OS compared to patients with sustained increase of PSA levels (18 vs. 8 months; HR 0.49, 95% CI 0.30–0.80; P < 0.01), but no significant difference relative to men with sustained PSA decrease (18 vs. 19 months; HR 1.4, 95% CI 0.78–2.49; P = 0.20). In addition, in men experiencing PSA fluctuations, median OS did not differ significantly between patients with initial decrease or initial increase of tumor marker levels (16 vs. 18 months; HR 1.2, 95% CI 0.38–4.05; P = 0.68).

Conclusion
Initial increase or decrease of PSA levels is sustained in the majority of patients undergoing RLT. Sustained PSA decrease was linked to prolonged survival and men with PSA fluctuations under treatment experienced comparable survival benefits. As such, transient tumor marker oscillations under RLT should rather not lead to treatment discontinuation, especially in the absence of radiological progression.
KW  - radioligand therapy
KW  - late response
KW  - flare phenomenon
KW  - PSA
KW  - prostate cancer
KW  - PSMA
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324562
VL  - 49
IS  - 13
ER  - 
TY  - JOUR
A1  - Giesel, Frederik L.
A1  - Kratochwil, Clemens
A1  - Schlittenhardt, Joel
A1  - Dendl, Katharina
A1  - Eiber, Matthias
A1  - Staudinger, Fabian
A1  - Kessler, Lukas
A1  - Fendler, Wolfgang P.
A1  - Lindner, Thomas
A1  - Koerber, Stefan A.
A1  - Cardinale, Jens
A1  - Sennung, David
A1  - Roehrich, Manuel
A1  - Debus, Juergen
A1  - Sathekge, Mike
A1  - Haberkorn, Uwe
A1  - Calais, Jeremie
A1  - Serfling, Sebastian
A1  - Buck, Andreas L.
T1  - Head-to-head intra-individual comparison of biodistribution and tumor uptake of \(^{68}\)Ga-FAPI and \(^{18}\)F-FDG PET/CT in cancer patients
JF  - European Journal of Nuclear Medicine and Molecular Imaging
N2  - Purpose
FAPI ligands (fibroblast activation protein inhibitor), a novel class of radiotracers for PET/CT imaging, demonstrated in previous studies rapid and high tumor uptake. The purpose of this study is the head-to-head intra-individual comparison of \(^{68}\)Ga-FAPI versus standard-of-care \(^{18}\)F-FDG in PET/CT in organ biodistribution and tumor uptake in patients with various cancers.

Material and Methods
This international retrospective multicenter analysis included PET/CT data from 71 patients from 6 centers who underwent both \(^{68}\)Ga-FAPI and \(^{18}\)F-FDG PET/CT within a median time interval of 10 days (range 1–89 days). Volumes of interest (VOIs) were manually drawn in normal organs and tumor lesions to quantify tracer uptake by SUVmax and SUVmean. Furthermore, tumor-to-background ratios (TBR) were generated (SUVmax tumor/ SUVmax organ).

Results
A total of 71 patients were studied of, which 28 were female and 43 male (median age 60). In 41 of 71 patients, the primary tumor was present. Forty-three of 71 patients exhibited 162 metastatic lesions. \(^{68}\)Ga-FAPI uptake in primary tumors and metastases was comparable to 18F-FDG in most cases. The SUVmax was significantly lower for \(^{68}\)Ga-FAPI than \(^{18}\)F-FDG in background tissues such as the brain, oral mucosa, myocardium, blood pool, liver, pancreas, and colon. Thus, \(^{68}\)Ga-FAPI TBRs were significantly higher than 18F-FDG TBRs in some sites, including liver and bone metastases.

Conclusion
Quantitative tumor uptake is comparable between \(^{68}\)Ga-FAPI and \(^{18}\)F-FDG, but lower background uptake in most normal organs results in equal or higher TBRs for \(^{68}\)Ga-FAPI. Thus, \(^{68}\)Ga-FAPI PET/CT may yield improved diagnostic information in various cancers and especially in tumor locations with high physiological \(^{18}\)F-FDG uptake.
KW  - FAPI PET/CT
KW  - FDG PET/CT
KW  - cancer-associated fibroblast
KW  - various cancer diseases
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-307252
SN  - 1619-7070
SN  - 1619-7089
VL  - 48
IS  - 13
ER  -