RT Journal Article SR Electronic T1 18F-rhPSMA-7 PET for the Detection of Biochemical Recurrence of Prostate Cancer After Curative-Intent Radiation Therapy: A Bicentric Retrospective Study JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1208 OP 1214 DO 10.2967/jnumed.121.262861 VO 63 IS 8 A1 Harun Ilhan A1 Markus Kroenke A1 Alexander Wurzer A1 Marcus Unterrainer A1 Matthias Heck A1 Claus Belka A1 Karina Knorr A1 Thomas Langbein A1 Isabel Rauscher A1 Nina-Sophie Schmidt-Hegemann A1 Kilian Schiller A1 Peter Bartenstein A1 Hans-Jürgen Wester A1 Matthias Eiber YR 2022 UL http://jnm.snmjournals.org/content/63/8/1208.abstract AB This bicentric, retrospective analysis investigated the efficacy of PET/CT with a novel theranostic prostate-specific membrane antigen (PSMA)--targeting ligand, 18F-rhPSMA-7, in patients with biochemical recurrence (BCR) of prostate cancer after curative-intent primary radiotherapy. Methods: Datasets from patients with BCR of prostate cancer after external-beam radiation therapy or brachytherapy who underwent 18F-rhPSMA-7 PET/CT at either Technical University Munich or Ludwig-Maximilians-University Munich were retrospectively reviewed by experienced nuclear medicine physicians and radiologists at both centers. The median injected activity was 299 MBq (range, 204–420 MBq), and the median uptake time was 77 min (range, 46–120 min). All lesions suggestive of recurrent prostate cancer were noted. Detection rates were correlated with patients’ prostate-specific antigen (PSA) level, primary Gleason score, and prior use of androgen-deprivation therapy (ADT). Results: Ninety-seven patients were included (65 at Technical University Munich and 32 at Ludwig-Maximilians-University Munich). The median prescan PSA was 4.19 ng/mL (range, 0.1–159 ng/mL). The primary Gleason score was ≤6 in 19 patients, 7 in 25, ≥8 in 33, and unknown in 20. Thirty patients received ADT in the 6 mo preceding PET/CT. 18F-rhPSMA-7 identified lesions in 91 of 97 (94%) patients. Detection rates stratified by PSA were 88% (22/25), 97% (30/31), 90% (19/21), and 100% (20/20) for a PSA of <2, 2–<5, 5–<10, and ≥10 ng/mL, respectively. Detection rates in the subgroup of patients not meeting the Phoenix criteria for BCR were 80% (4/5), 90% (9/10), 100% (4/4), and 83% (5/6) for a PSA of <0.5, 0.5–<1, 1–<1.5, and 1.5–2 ng/mL, respectively. There were no significant differences in detection rates between patients with and without prior ADT (100% vs. 91%, P = 0.173) or patients with a Gleason score of ≤7 and a Gleason score of ≥8 (98% vs. 91%, P = 0.316).18F-rhPSMA-7 revealed local recurrence in 80% (78/97); pelvic lymph node metastases in 38% (37/97); retroperitoneal and supradiaphragmatic lymph node metastases in 9% (9/97) and 4% (4/97), respectively; bone metastases in 27% (26/97); and visceral metastases in 3% (3/97). In the subgroup of patients with a PSA of <2 ng/mL above nadir, local recurrence occurred in 76% (19/25) and pelvic lymph node metastases in 36% (9/25). Conclusion: 18F-rhPSMA-7 PET/CT demonstrates high detection rates in prostate cancer patients with BCR after primary radiation therapy, even at low PSA values. Its diagnostic efficacy is comparable to published data for other PSMA ligands.