% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Heilinger:1038069, author = {Heilinger, Jan and Roth, Katrin Sabine and Weis, Henning and Fink, Antonis and Weindler, Jasmin and Dietlein, Felix and Krapf, Philipp and Schomäcker, Klaus and Neumaier, Bernd and Dietlein, Markus and Drzezga, Alexander and Kobe, Carsten}, title = {{D}o you know your {PSMA}-tracer? {V}ariability in the biodistribution of different {PSMA} ligands and its potential impact on defining {PSMA}-positivity prior to {PSMA}-targeted therapy}, journal = {EJNMMI Research}, volume = {15}, number = {1}, issn = {2191-219X}, address = {Heidelberg}, publisher = {Springer}, reportid = {FZJ-2025-01118}, pages = {4}, year = {2025}, abstract = {Background In clinical practice, several radiopharmaceuticals are used for PSMA-PET imaging, each with distinctbiodistribution patterns. This may impact treatment decisions and outcomes, as eligibility for PSMA-directedradioligand therapy is usually assessed by comparing tumoral uptake to normal liver uptake as a reference. In thisstudy, we aimed to compare tracer uptake intraindividually in various reference regions including liver, parotid glandand spleen as well as the respective tumor-to-background ratios (TBR) of different 18F-labeled PSMA ligands to today’sstandard radiopharmaceutical 68Ga-PSMA-11 in a series of patients with biochemical recurrence of prostate cancerwho underwent a dual PSMA-PET examination as part of an individualized diagnostic approach.Results Differences in background activity among different PSMA-PET tracers lead to variations in tumor-tobackgroundratios (TBR). In [18F]F-DCFPyL-PET, TBR with the liver as the reference organ (TBRliver) was comparableto [68Ga]Ga-PSMA-11-PET, while [18F]F-PSMA-1007-PET and [18F]F-JK-PSMA-7-PET showed significantly lower values.Using the parotid gland as the reference (TBRparotidgland), [18F]F-DCFPyL-PET exhibited significantly higher values,whereas [18F]F-PSMA-1007-PET and [18F]F-JK-PSMA-7-PET were comparable. For the spleen (TBRspleen), [18F]F-JK-PSMA-7-PET was comparable, but [18F]F-DCFPyL-PET and [18F]F-PSMA-1007-PET showed significantly higher and lowervalues, respectively. An additional Bland-Altman analyses revealed low bias for [18F]F-DCFPyL-PET in TBRparotidgland,whereas significant differences in TBRliver and TBRspleen for the other tracers resulted in higher bias.Conclusion Different PSMA-PET tracers exhibit distinct biodistribution patterns, leading to variations in tumor-tobackgroundratios (TBR) in reference organs such as the liver, parotid gland, and spleen. Patient selection for PSMA-directed radioligand therapy is currently based on a semiquantitative approach using the liver as a reference regionin [68Ga]Ga-PSMA-11-PET. Thus, the use of alternative [18F]-labeled tracers may result in under- or overestimation of apatient’s suitability for therapy. This highlights the importance of a comprehensive understanding of the differencesin tracer-specific uptake behavior for accurate decisions regarding PSMA-expression levels. However, as the patientcohort in this study is at earlier disease stages, the generalizability of these findings to later-stage patients remainsunclear and requires further investigation.}, cin = {INM-5 / INM-2}, ddc = {610}, cid = {I:(DE-Juel1)INM-5-20090406 / I:(DE-Juel1)INM-2-20090406}, pnm = {5253 - Neuroimaging (POF4-525)}, pid = {G:(DE-HGF)POF4-5253}, typ = {PUB:(DE-HGF)16}, pubmed = {39792324}, UT = {WOS:001394361800001}, doi = {10.1186/s13550-024-01190-7}, url = {https://juser.fz-juelich.de/record/1038069}, }