Recently, prostate-specific membrane antigen (PSMA) targeted PET-imaging has emerged as new method of staging and restaging of prostate cancer. Most published studies have investigated the diagnostic potential of Ga-labeled PSMA-agents which are excreted renally. [F]PSMA-1007 is a novel PSMA-ligand with excellent preclinical characteristics which 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 [F]PSMA-1007 in biochemical recurrence (BCR) after radical prostatectomy (RP). 251 patients from three academic centers with BCR after radical prostatectomy were evaluated in a retrospective analysis. Patients who had received second line androgen deprivation therapy and/or chemotherapy were excluded, however prior first line ADT exposure was allowed. The median PSA-level was 1.2 ng/ml (range: 0.2-228 ng/mL). All patients underwent a PSMA-PET/CT after injection of 301±46 MBq [F]PSMA-1007 at 92±26 min post injection. The detection rate of presumed recurrence sites was correlated with PSA-level and original primary Gleason score. A comparison to a subset of patients treated previously with androgen deprivation therapy (ADT) was undertaken. 204 of 251 patients (81.3%) patients had evidence of recurrence on [F]PSMA-1007 PET/CT. The detection rates were 94.1% (79/84), 90.1% (50/55), 74.5% (35/47) and 61.5% (40/65) for PSA-levels of ≥2, 1-<2, 0.5-<1 and 0.2-<0.5ng/mL, respectively. [F]PSMA-1007 PET/CT revealed local recurrence in 43.7% (62) of patients. Lymph node metastases were present in the pelvis in 40.6% (102), in the retroperitoneum in 19.5% (49) and in supradiaphragmatic locations in 12.0% (30) of patients. Bone and visceral metastases were detected in 40.2% (101) and 3.6% (9) patients. In higher Gleason score tumors (≤7vs.≥8) detection efficacy trended higher (76.3% vs. 86.7%) but was not statistically significant ( = 0.32). However, detection efficacy was higher in patients who had previously been on ADT (91.7% vs. 78.0%) within 6 months prior to imaging ( = 0.0179). [F]PSMA-1007 PET/CT offers high detection rates in BCR after radical prostatectomy which is comparable to or better than that published for Ga-labelled PSMA-ligands.

18 F-labeled prostate-specific membrane antigen (PSMA)-ligand PET has several principal advantages over 68 Ga-PSMA-11. The purpose of this retrospective study was to evaluate the frequency of non-tumor-related uptake and the detection efficacy comparing 68 Ga-PSMA-11 PET/CT and 18 F-PSMA-1007 PET/CT in recurrent prostate cancer (PC) patients. Methods: The study included 102 patients with biochemically recurrent PC after radical prostatectomy undergoing 18 F-PSMA-1007 PET/CT imaging. On the basis of various clinical variables, patients with corresponding 68 Ga-PSMA-11 PET/CT scans were matched. All PET/CT scans (n 5 204) were reviewed by 1 nuclear medicine physician. First, all PET-positive lesions were noted. Then, lesions suspected of being recurrent PC were differentiated from lesions attributed to a benign origin on the basis of known pitfalls and information from CT. For each region, the SUV max of the lesion with the highest PSMA-ligand uptake was noted. Detection rates were determined, and SUV max was compared separately for 68 Ga-PSMA-11 and 18 F-PSMA-1007. Results: In total, 18 F-PSMA-1007 PET and 68 Ga-PSMA-11 PET revealed 369 and 178 PSMA-ligand-positive lesions, respectively. 18 F-PSMA-1007 PET revealed approximately 5 times more lesions attributed to a benign origin than did 68 Ga-PSMA-11 PET (245 vs. 52 lesions, respectively). The benign lesions most frequently observed were ganglia, unspecific lymph node, and bone lesions, at a rate of 43%, 31%, and 24% for 18 F-PSMA-1007 PET and 29%, 42%, and 27% for 68 Ga-PSMA-11 PET, respectively. The SUV max of lesions attributed to a benign origin was significantly higher (P , 0.0001) for 18 F-PSMA-1007 PET. Further, a similar number of lesions was attributed to recurrent PC (124/369 for 18 F-PSMA-1007 PET and 126/178 for 68 Ga-PSMA-11 PET). Conclusion: The number of lesions with increased PSMA-ligand uptake attributed to a benign origin is considerably higher for 18 F-PSMA-1007 PET than for 68 Ga-PSMA-11 PET. This finding indicates the need for sophisticated reader training emphasizing known pitfalls and reporting within the clinical context.

Ga-PSMA-PET imaging showed a high clinical impact on staging and RT management in patients with biochemically recurrent PC, even at low serum PSA levels. With 43% changes in staging and 59% in radiotherapy planning Ga-PSMA-PET could lead to an indispensable tool in guiding radiation treatment in recurrent PC.

BackgroundThe impact of local tumor ablative therapy in oligometastasized prostate cancer (PC) is still under debate. To gain data for this approach, we evaluated oligometastasized PC patients receiving stereotactic body radiotherapy (SBRT) to bone metastases.MethodsIn this retrospective study, 15 oligometastasized PC patients with a total of 20 bone metastases were evaluated regarding biochemical progression-free survival (PSA-PFS), time to initiation of ADT, and local control rate (LCR). Three patients received concomitant androgen deprivation therapy (ADT).ResultsThe median follow-up after RT was 22.5 months (range 7.0–53.7 months). The median PSA-PFS was 6.9 months (range 1.1–28.4 months). All patients showing a decrease of PSA level after RT of at least factor 10 reveal a PSA-PFS of >12 months. Median PSA-PFS of this sub-group was 23.1 months (range 12.1–28.4 months). Local PFS (LPFS) after 2 years was 100%. One patient developed a local failure after 28.4 months. Median distant PFS (DPFS) was 7.36 months (range 1.74–54.34 months). The time to initiation of ADT in patients treated without ADT was 9.3 months (range 2.6–36.1 months). In all patients, the time to intensification of systemic therapy or the time to initiation of ADT increased from 9.3 to 12.3 months (range 2.6–36.1 months). Gleason-Score, ADT or the localization of metastasis had no impact on PFS or time to intensification of systemic therapy. No SBRT related acute or late toxicities were observed.ConclusionOur study shows that SBRT of bone metastases is a highly effective therapy with an excellent risk-benefit profile. However, PFS was limited due to a high distant failure rate implying the difficulty for patient selection for this oligometastatic concept. SBRT offers high local cancer control rates in bone oligometastases of PC and should be evaluated with the aim of curation or to delay modification of systemic treatment.