@article {Kuten527, author = {Jonathan Kuten and Ibrahim Fahoum and Ziv Savin and Ofer Shamni and Gilad Gitstein and Dov Hershkovitz and Nicola J. Mabjeesh and Ofer Yossepowitch and Eyal Mishani and Einat Even-Sapir}, title = {Head-to-Head Comparison of 68Ga-PSMA-11 with 18F-PSMA-1007 PET/CT in Staging Prostate Cancer Using Histopathology and Immunohistochemical Analysis as a Reference Standard}, volume = {61}, number = {4}, pages = {527--532}, year = {2020}, doi = {10.2967/jnumed.119.234187}, publisher = {Society of Nuclear Medicine}, abstract = {18F-PSMA-1007 is a novel prostate-specific membrane antigen (PSMA){\textendash}based radiopharmaceutical for imaging prostate cancer (PCa). The aim of this study was to compare the diagnostic accuracy of 18F-PSMA-1007 with 68Ga-PSMA-11 PET/CT in the same patients presenting with newly diagnosed intermediate- or high-risk PCa. Methods: Sixteen patients with intermediate- or high-risk PCa underwent 18F-PSMA-1007 and 68Ga-PSMA-11 PET/CT within 15 d. PET findings were compared between the 2 radiotracers and with reference-standard pathologic specimens obtained from radical prostatectomy. The Cohen κ-coefficient was used to assess the concordance between 18F-PSMA-1007 and 68Ga-PSMA-11 for detection of intraprostatic lesions. The McNemar test was used to assess agreement between intraprostatic PET/CT findings and histopathologic findings. Sensitivity, specificity, positive predictive value, and negative predictive value were reported for each radiotracer. SUVmax was measured for all lesions, and tumor-to-background activity was calculated. Areas under receiver-operating-characteristic curves were calculated for discriminating diseased from nondiseased prostate segments, and optimal SUV cutoffs were calculated using the Youden index for each radiotracer. Results: PSMA-avid lesions in the prostate were identified in all 16 patients with an almost perfect concordance between the 2 tracers (κ ranged from 0.871 to 1). Aside from the dominant intraprostatic lesion, similarly detected by both radiotracers, a second less intense positive focus was detected in 4 patients only with 18F-PSMA-1007. Three of these secondary foci were confirmed as Gleason grade 3 lesions, whereas the fourth was shown on pathologic examination to represent chronic prostatitis. Conclusion: This pilot study showed that both 18F-PSMA-1007 and 68Ga-PSMA-11 identify all dominant prostatic lesions in patients with intermediate- or high-risk PCa at staging. 18F-PSMA-1007, however, may detect additional low-grade lesions of limited clinical relevance.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/61/4/527}, eprint = {https://jnm.snmjournals.org/content/61/4/527.full.pdf}, journal = {Journal of Nuclear Medicine} }