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  - Werner, Rudolf A.
A1  - Ordonez, Alvaro A.
A1  - Sanchez-Bautista, Julian
A1  - Marcus, Charles
A1  - Lapa, Constantin
A1  - Rowe, Steven P.
A1  - Pomper, Martin G.
A1  - Leal, Jeffrey P.
A1  - Lodge, Martin A.
A1  - Javadi, Mehrbod S.
A1  - Jain, Sanjay K.
A1  - Higuchi, Takahiro
T1  - Novel functional renal PET imaging with 18F-FDS in human subjects
JF  - Clinical Nuclear Medicine
N2  - The novel PET probe 2-deoxy-2-18F-fluoro-D-sorbitol (18F-FDS) has demonstrated favorable renal kinetics in animals. We aimed to elucidate its imaging properties in two human volunteers. 18F-FDS was produced by a simple one-step reduction from 18F-FDG. On dynamic renal PET, the cortex was delineated and activity gradually transited in the parenchyma, followed by radiotracer excretion. No adverse effects were reported. Given the higher spatiotemporal resolution of PET relative to conventional scintigraphy, 18F-FDS PET offers a more thorough evaluation of human renal kinetics. Due to its simple production from 18F-FDG, 18F-FDS is virtually available at any PET facility with radiochemistry infrastructure.
KW  - 2-deoxy-2-18F-fluoro-D-sorbitol
KW  - Positronen-Emissions-Tomografie
KW  - 18F-FDS
KW  - renal imaging
KW  - Positron-Emission Tomography
KW  - split renal function
KW  - kidney
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-174634
SN  - 0363-9762
VL  - 44
IS  - 5
ER  - 
TY  - JOUR
A1  - Khatri, Wajahat
A1  - Chung, Hyun Woo
A1  - Werner, Rudolf A.
A1  - Leal, Jeffrey P.
A1  - Pienta, Kenneth J.
A1  - Lodge, Martin A.
A1  - Gorin, Michael A.
A1  - Pomper, Martin G.
A1  - Rowe, Steven P.
T1  - Effect of point-spread function reconstruction for indeterminate PSMA-RADS-3A lesions on PSMA-targeted PET imaging of men with prostate cancer
JF  - Diagnostics
N2  - Purpose: Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) is emerging as an important modality for imaging patients with prostate cancer (PCa). As with any imaging modality, indeterminate findings will arise. The PSMA reporting and data system (PSMA-RADS) version 1.0 codifies indeterminate soft tissue findings with the PSMA-RADS-3A moniker. We investigated the role of point-spread function (PSF) reconstructions on categorization of PSMA-RADS-3A lesions. Methods: This was a post hoc analysis of an institutional review board approved prospective trial. Around 60 min after the administration of 333 MBq (9 mCi) of PSMA-targeted \(^{18}\)F-DCFPyL, patients underwent PET/computed tomography (CT) acquisitions from the mid-thighs to the skull vertex. The PET data were reconstructed with and without PSF. Scans were categorized according to PSMA-RADS version 1.0, and all PSMA-RADS-3A lesions on non-PSF images were re-evaluated to determine if any could be re-categorized as PSMA-RADS-4. The maximum standardized uptake values (SUVs) of the lesions, mean SUVs of blood pool, and the ratios of those values were determined. Results: A total of 171 PSMA-RADS-3A lesions were identified in 30 patients for whom both PSF reconstructions and cross-sectional imaging follow-up were available. A total of 13/171 (7.6%) were re-categorized as PSMA-RADS-4 lesions with PSF reconstructions. A total of 112/171 (65.5%) were found on follow-up to be true positive for PCa, with all 13 of the re-categorized lesions being true positive on follow-up. The lesions that were re-categorized trended towards having higher SUV\(_{max}\)-lesion and SUV\(_{max}\)-lesion/SUV\(_{mean}\)-blood-pool metrics, although these relationships were not statistically significant. Conclusions: The use of PSF reconstructions for \(^{18}\)F-DCFPyL PET can allow the appropriate re-categorization of a small number of indeterminate PSMA-RADS-3A soft tissue lesions as more definitive PSMA-RADS-4 lesions. The routine use of PSF reconstructions for PSMA-targeted PET may be of value at those sites that utilize this technology.
KW  - prostate-specific membrane antigen
KW  - reporting and data system
KW  - positron emission tomography
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236528
SN  - 2075-4418
VL  - 11
IS  - 4
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  -