TY - JOUR
A1 - Lapa, Constantin
A1 - Reiter, Theresa
A1 - Kircher, Malte
A1 - Schirbel, Andreas
A1 - Werner, Rudolf A.
A1 - Pelzer, Theo
A1 - Pizarro, Carmen
A1 - Skowasch, Dirk
A1 - Thomas, Lena
A1 - Schlesinger-Irsch, Ulrike
A1 - Thomas, Daniel
A1 - Bundschuh, Ralph A.
A1 - Bauer, Wolfgang R.
A1 - Gartner, Florian C.
T1 - Somatostatin receptor based PET/CT in patients with the suspicion of cardiac sarcoidosis: an initial comparison to cardiac MRI
JF - Oncotarget
N2 - Diagnosis of cardiac sarcoidosis is often challenging. Whereas cardiac magnetic resonance imaging (CMR) and positron emission tomography/computed tomography (PET/CT) with \(^{18}\)F-fluorodeoxyglucose (FDG) are most commonly used to evaluate patients, PET/CT using radiolabeled somatostatin receptor (SSTR) ligands for visualization of inflammation might represent a more specific alternative. This study aimed to investigate the feasibility of SSTR–PET/CT for detecting cardiac sarcoidosis in comparison to CMR.
15 patients (6 males, 9 females) with sarcoidosis and suspicion on cardiac involvement underwent SSTR-PET/CT imaging and CMR. Images were visually scored. The AHA 17-segment model of the left myocardium was used for localization and comparison of inflamed myocardium for both imaging modalities. In semi-quantitative analysis, mean (SUV\(_{mean}\)) and maximum standardized uptake values (SUV\(_{max}\)) of affected myocardium were calculated and compared with both remote myocardium and left ventricular (LV) cavity.
SSTR-PET was positive in 7/15, CMR in 10/15 patients. Of the 3 CMR+/PET- subjects, one patient with minor involvement (<25% of wall thickness in CMR) was missed by PET. The remaining two CMR+/PET- patients displayed no adverse cardiac events during follow-up.
In the 17-segment model, PET/CT yielded 27 and CMR 29 positive segments. Overall concordance of the 2 modalities was 96.1% (245/255 segments analyzed). SUV\(_{mean}\) and SUV\(_{max}\) in inflamed areas were 2.0±1.2 and 2.6±1.2, respectively. The lesion-to-remote myocardium and lesion-to-LV cavity ratios were 1.8±0.2 and 1.9±0.2 for SUV\(_{mean}\) and 2.0±0.3 and 1.7±0.3 for SUV\(_{max}\), respectively.
Detection of cardiac sarcoidosis by SSTR-PET/CT is feasible. Our data warrant further analysis in larger prospective series.
KW - sarcoidosis
KW - PET
KW - SSTR
KW - somatostatin receptor
KW - DOTATOC
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175423
VL - 7
IS - 47
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 - 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 - 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 - Kläsner, Benjamin
A1 - Buchmann, Niels
A1 - Gempt, Jens
A1 - Ringel, Florian
A1 - Lapa, Constantin
A1 - Krause, Bernd Joachim
T1 - Early [\(^{18}\)F]FET-PET in Gliomas after Surgical Resection: Comparison with MRI and Histopathology
JF - PLoS One
N2 - Background The precise definition of the post-operative resection status in high-grade gliomas (HGG) is crucial for further management. We aimed to assess the feasibility of assessment of the resection status with early post-operative positron emission tomography (PET) using [\(^{18}\)F]O-(2-[\(^{18}\)F]-fluoroethyl)-L-tyrosine ([\(^{18}\)F]FET). Methods 25 patients with the suspicion of primary HGG were enrolled. All patients underwent preoperative [\(^{18}\)F]FET-PET and magnetic resonance imaging (MRI). Intra-operatively, resection status was assessed using 5-aminolevulinic acid (5-ALA). Imaging was repeated within 72h after neurosurgery. Post-operative [\(^{18}\)F]FET-PET was compared with MRI, intra-operative assessment and clinical follow-up. Results [\(^{18}\)F]FET-PET, MRI and intra-operative assessment consistently revealed complete resection in 12/25 (48%) patients and incomplete resection in 6/25 cases (24%). In 7 patients, PET revealed discordant findings. One patient was re-resected. 3/7 experienced tumor recurrence, 3/7 died shortly after brain surgery. Conclusion Early assessment of the resection status in HGG with [\(^{18}\)F]FET-PET seems to be feasible.
KW - glioblastoma multiforme
KW - brain tumors
KW - C-11-methionine pet
KW - positron-emission-tomography
KW - improves
KW - survival
KW - delineation
KW - radiotherapy
KW - methionine pet
KW - cerebral gliomas
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-139549
VL - 10
IS - 10
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 - 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 - 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 - 68Ga-Pentixafor
KW - 18F-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 -