(18)F-rhPSMA-7 PET for the Detection of Biochemical Recurrence of Prostate Cancer After Radical Prostatectomy.

18F-labeled prostate-specific membrane antigen (PSMA) PET tracers are increasingly used in preference to 68Ga-PSMA-11 for restaging biochemical recurrence (BCR) of prostate cancer. They are associated with longer half-lives, larger-scale production, and lower positron range than their 68Ga-labeled counterparts. Here, we describe the efficacy of an 18F-labeled radiohybrid PSMA, rhPSMA-7, a novel theranostic PSMA-targeting agent for imaging BCR of prostate cancer. Methods: Datasets from 261 consecutive patients with noncastrate BCR after radical prostatectomy who underwent 18F-rhPSMA-7 PET/CT at our institution between June 2017 and March 2018 were reviewed retrospectively. All lesions suspected of being recurrent prostate cancer were recorded. The detection rate for sites of presumed recurrence was correlated with patients' prostate-specific antigen (PSA) level, primary Gleason score, and prior therapy (androgen deprivation therapy and external-beam radiation therapy). Results: The 261 patients had a median PSA level of 0.96 ng/mL (range, 0.01-400 ng/mL). The median injected activity of 18F-rhPSMA-7 was 336 MBq, with a median uptake time of 76 min. In total, 211 patients (81%) showed pathologic findings on 18F-rhPSMA-7 PET/CT. The detection rates were 71% (42/59), 86% (44/51), 86% (42/49), and 95% (76/80) at PSA levels of 0.2 to <0.5 ng/mL, 0.5 to <1 ng/mL, 1 to <2 ng/mL, and ≥2 ng/mL, respectively. In 32% patients (7/22) with a PSA of less than 0.2 ng/mL, suggestive lesions were present. 18F-rhPSMA-7 PET/CT revealed local recurrence in 43% of patients (113). Lymph node metastases were present in the pelvis in 42% of patients (110), in the retroperitoneum in 17% (45), and in a supradiaphragmatic location in 8.0% (21). Bone and visceral metastases were detected in 21% (54) and 3.8% (10), respectively. Detection efficacy was not influenced by prior external-beam radiation therapy (79.1% vs. 82.1%, P = 0.55), androgen deprivation therapy within the 6 mo preceding imaging (80.6% vs. 80.9%, P = 0.54), or primary Gleason score (77.9% for ≤7 vs. 82.6% for ≥8, P = 0.38). Conclusion:18F-rhPSMA-7 PET/CT offers high detection rates in early BCR after radical prostatectomy, especially among patients with low PSA values.

Eiber M ，Kroenke M ，Wurzer A ，Ulbrich L ，Jooß L ，Maurer T ，Horn T ，Schiller K ，Langbein T ，Buschner G ，Wester HJ ，Weber W ... -  《-》

(18)F-rhPSMA-7 PET for the Detection of Biochemical Recurrence of Prostate Cancer After Curative-Intent Radiation Therapy: A Bicentric Retrospective Study.

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.

Ilhan H ，Kroenke M ，Wurzer A ，Unterrainer M ，Heck M ，Belka C ，Knorr K ，Langbein T ，Rauscher I ，Schmidt-Hegemann NS ，Schiller K ，Bartenstein P ，Wester HJ ，Eiber M ... -  《-》

Detection Efficacy of (18)F-PSMA-1007 PET/CT in 251 Patients with Biochemical Recurrence of Prostate Cancer After Radical Prostatectomy.

Prostate-specific membrane antigen (PSMA)-targeted PET imaging recently emerged as a new method for the staging and restaging of prostate cancer. Most published studies investigated the diagnostic potential of 68Ga-labeled PSMA agents that are excreted renally. 18F-PSMA-1007 is a novel PSMA ligand that has excellent preclinical characteristics and that is only minimally excreted by the urinary tract, a potential advantage for pelvic imaging. The aim of this study was to investigate the diagnostic efficacy of 18F-PSMA-1007 for biochemical recurrence (BCR) after radical prostatectomy. Methods: From 3 academic centers, 251 patients with BCR after radical prostatectomy were evaluated in a retrospective analysis. Patients who had received second-line androgen deprivation therapy (ADT) or chemotherapy were excluded, but prior first-line ADT exposure was allowed. The median prostate-specific antigen (PSA) level was 1.2 ng/mL (range, 0.2-228 ng/mL). All patients underwent PSMA PET/CT at 92 ± 26 min after injection of 301 ± 46 MBq of 18F-PSMA-1007. The rate of detection of presumed recurrence sites was correlated with the PSA level and original primary Gleason score. A comparison to a subset of patients treated previously with ADT was undertaken. Results: Of the 251 patients, 204 (81.3%) had evidence of recurrence on 18F-PSMA-1007 PET/CT. The detection rates were 94.0% (79/84), 90.9% (50/55), 74.5% (35/47), and 61.5% (40/65) for PSA levels of greater than or equal to 2, 1 to less than 2, 0.5 to less than 1, and 0.2 to less than 0.5 ng/mL, respectively. 18F-PSMA-1007 PET/CT revealed local recurrence in 24.7% of patients (n = 62). Lymph node metastases were present in the pelvis in 40.6% of patients (n = 102), in the retroperitoneum in 19.5% of patients (n = 49), and in supradiaphragmatic locations in 12.0% of patients (n = 30). Bone and visceral metastases were detected in 40.2% of patients (n = 101) and in 3.6% of patients (n = 9), respectively. In tumors with higher Gleason scores (≤7 vs. ≥8), detection efficacy trended higher (76.3% vs. 86.7%) but was not statistically significant (P = 0.32). However, detection efficacy was higher in patients who had received ADT (91.7% vs. 78.0%) within 6 mo before imaging (P = 0.0179). Conclusion:18F-PSMA-1007 PET/CT offers high detection rates for BCR after radical prostatectomy that are comparable to or better than those published for 68Ga-labeled PSMA ligands.

Giesel FL ，Knorr K ，Spohn F ，Will L ，Maurer T ，Flechsig P ，Neels O ，Schiller K ，Amaral H ，Weber WA ，Haberkorn U ，Schwaiger M ，Kratochwil C ，Choyke P ，Kramer V ，Kopka K ，Eiber M ... -  《-》

Histologically Confirmed Diagnostic Efficacy of (18)F-rhPSMA-7 PET for N-Staging of Patients with Primary High-Risk Prostate Cancer.

18F-rhPSMA-7 (radiohybrid prostate-specific membrane antigen [PSMA]) is a novel ligand for PET imaging. Here, we present data from a retrospective analysis using PET/CT and PET/MRI examinations to investigate the efficacy of 18F-rhPSMA-7 PET for primary N-staging of patients with prostate cancer (PC) compared with morphologic imaging (CT or MRI) and validated by histopathology. Methods: Data from 58 patients with high-risk PC (according to the D'Amico criteria) who were staged with 18F-rhPSMA-7 PET/CT or PET/MRI at our institution between July 2017 and June 2018 were reviewed. The patients had a median prescan prostate-specific antigen value of 12.2 ng/mL (range, 1.2-81.6 ng/mL). The median injected activity of 18F-rhPSMA-7 was 327 MBq (range, 132-410 MBq), with a median uptake time of 79.5 min (range, 60-153 min). All patients underwent subsequent radical prostatectomy and extended pelvic lymph node dissection. The presence of lymph node metastases was determined by an experienced reader independently for both the PET and the morphologic datasets using a template-based analysis on a 5-point scale. Patient-level and template-based results were both compared with histopathologic findings. Results: Lymph node metastases were present in 18 patients (31.0%) and were located in 52 of 375 templates (13.9%). Receiver-operating-characteristic analyses showed 18F-rhPSMA-7 PET to perform significantly better than morphologic imaging on both patient-based and template-based analyses (areas under curve, 0.858 vs. 0.649 [P = 0.012] and 0.765 vs. 0.589 [P < 0.001], respectively). On patient-based analyses, the sensitivity, specificity, and accuracy of 18F-rhPSMA-7 PET were 72.2%, 92.5%, and 86.2%, respectively, and those of morphologic imaging were 50.0%, 72.5%, and 65.5%, respectively. On template-based analyses, the sensitivity, specificity, and accuracy of 18F-rhPSMA-7 PET were 53.8%, 96.9%, and 90.9%, respectively, and those of morphologic imaging were 9.6%, 95.0%, and 83.2%, respectively. Conclusion:18F-rhPSMA-7 PET is superior to morphologic imaging for N-staging of high-risk primary PC. The efficacy of 18F-rhPSMA-7 is similar to published data for 68Ga-PSMA-11.

Kroenke M ，Wurzer A ，Schwamborn K ，Ulbrich L ，Jooß L ，Maurer T ，Horn T ，Rauscher I ，Haller B ，Herz M ，Wester HJ ，Weber WA ，Eiber M ... -  《-》

More advantages in detecting bone and soft tissue metastases from prostate cancer using (18)F-PSMA PET/CT.

Pianou NK ，Stavrou PZ ，Vlontzou E ，Rondogianni P ，Exarhos DN ，Datseris IE ... -  《Hellenic Journal of Nuclear Medicine》