(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 ... -  《-》

(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 ... -  《-》

Positive Predictive Value and Correct Detection Rate of (18)F-rhPSMA-7 PET in Biochemically Recurrent Prostate Cancer Validated by Composite Reference Standard.

The objective of this retrospective study was to assess the detection rate (DR), positive predictive value (PPV), and correct detection rate (CDR) of 18F-rhPSMA-7 PET/CT in biochemical recurrence (BCR) of prostate cancer (PCa) after radical prostatectomy (RP) using composite validation. Methods:18F-rhPSMA-7 PET/CT scans of patients with BCR between July 2017 and June 2018 were retrospectively reviewed. All suspicious lesions were recorded. The reference standard was histopathology or combinations of histopathology, imaging, or prostate-specific antigen (PSA) follow up, defined as composite reference standard. DR was calculated as the proportion of PSMA PET-positive patients to all patients independent of the reference standard, whereas the CDR was the percentage of patients who had at least 1 true-positive PSMA PET lesion localized that corresponded with the reference standard. The PPV was defined as the proportion of patients who had true-positive to all positive findings. The correlation between DR and patient characteristics was evaluated. Results: A total of 532 patients with a median PSA level of 0.97 ng/mL (interquartile range: 0.41-2.46 ng/mL) were included. Of these, 162 patients had composite follow-up at a median duration of 5.6 mo (range: 1.1-14.2 mo). The proportion of patients who had no lesion visualized on PET/CT, localized disease, and any distant metastases (M1) were 20%, 43%, and 37%, respectively. PET DR among all patients was 80%. On a per-patient basis, the PPV of 18F-rhPSMA-7 PET/CT in the composite cohort was 88%, and the CDR was 70%. The PPV in the histopathology-proven cohort was 91%, and the CDR in this subgroup was 73%. In patients with PSA levels ≥ 1 ng/mL the DR and PPV were 90% and 91%, respectively, resulting in a CDR of 82%. In patients with PSA levels < 1 ng/mL, the DR and PPV were 69% and 85%, respectively, resulting in a CDR of 59%. There was a significant positive correlation between 18F-rhPSMA-7 PET/CT detection efficacy and stratified PSA levels (P = 0.005), as well as PSA nadir after prostatectomy (P < 0.001). Conclusion:18F-rhPSMA-7 PET/CT offers high PPV in BCR after RP. Its CDR is dependent on the prescan PSA value with excellent CDR in patients with PSA ≥ 1 ng/mL.

Chantadisai M ，Buschner G ，Krönke M ，Rauscher I ，Langbein T ，Nekolla SG ，Schiller K ，Heck MM ，Maurer T ，Wurzer A ，Wester HJ ，D'Alessandria C ，Weber W ，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》

Detection Efficacy of Hybrid (68)Ga-PSMA Ligand PET/CT in Prostate Cancer Patients with Biochemical Recurrence After Primary Radiation Therapy Defined by Phoenix Criteria.

The aim of this retrospective study was to evaluate the detection rate of Glu-NH-CO-NH-Lys-(Ahx)-[68Ga(HBED-CC)] (68Ga-PSMA ligand; PSMA is prostate-specific membrane antigen) PET/CT in patients with biochemical recurrent prostate cancer defined by Phoenix criteria after external-beam radiotherapy or brachytherapy as primary treatment. Methods: One hundred eighteen patients with a median prostate-specific antigen (PSA) of 6.4 ng/mL (range, 2.2-158.4 ng/mL; interquartile range, 4.2-10.2 ng/mL) were finally eligible for this retrospective analysis. Seventy-seven and 41 patients had been treated by external-beam radiotherapy or brachytherapy, respectively. Of the 118 patients, 45 were receiving androgen-deprivation therapy (ADT) within at least 6 mo before the PET/CT. The detection rates were stratified by PSA. The influence of primary Gleason score and ADT was assessed. Relationships between SUV and clinical as well as pathologic features in patients with positive findings were analyzed using univariate and multivariable linear regression models. Results: One hundred seven of 118 patients (90.7%) showed pathologic findings indicative for tumor recurrence in 68Ga-PSMA ligand PET/CT. The detection rates were 81.8% (36/44), 95.3% (41/43), and 96.8% (30/31) for PSA of 2 to <5, 5 to <10, and ≥10 ng/mL, respectively (P = 0.0377). 68Ga-PSMA ligand PET/CT indicated local recurrence in 68 of 107 patients (63.5%), distant lesions in 64 of 107 patients (59.8%), and local recurrence as well as distant lesions in 25 of 107 patients (23.4%). The detection rate was significantly higher in patients with ADT (97.7%) versus without ADT (86.3%, P = 0.0381), but independent from primary Gleason score ≥ 8 (92.0%) versus ≤ 7 (90.2%, P = 0.6346). SUVmax and SUVmean were significantly associated with PSA and ADT (P = 0.018 and 0.004 for SUVmax, respectively; P = 0.025 and 0.007 for SUVmean, respectively). Conclusion:68Ga-PSMA ligand PET/CT demonstrates high detection rates in patients with biochemical recurrence of prostate cancer after primary radiation therapy. The detection rate was positively associated to increasing PSA as well as concomitant ADT. 68Ga-PSMA ligand PET/CT enables discrimination of local versus metastatic disease and thus might have a crucial impact on further clinical management. A major limitation of this study is the lack of histopathologic proof in most patients.

Einspieler I ，Rauscher I ，Düwel C ，Krönke M ，Rischpler C ，Habl G ，Dewes S ，Ott A ，Wester HJ ，Schwaiger M ，Maurer T ，Eiber M ... -  《-》