Enhancing PSMA-uptake with androgen deprivation therapy - a new way to detect prostate cancer metastases?

ABSTRACT Purpose: 68Ga-PSMA PET/CT imaging is a promising modality for the staging of recurrent prostate cancer (PCa). Current evidence suggests limited diagnostic value of the 68Ga-PSMA PET/CT in PSA-levels ≤0.3ng/mL. Experimental data have demonstrated an increase in PSMA-expression in PCa metastases by androgen deprivation in vitro. The aim of the current study was to investigate a possible enhancing effect of PSMA with low-dose androgen deprivation in patients with BCR and low PSA-levels. Materials and Methods: Five patients with PCa and BCR, following radical prostatectomy, underwent 68Ga-PSMA PET/CT. A consecutive 68Ga-PSMA PET/CT was performed 6 to 11 days after injection of 80mg of Degarelix (Firmagon®). We recorded PSA and testosterone serum-levels and changes of PSMA-uptake in 68Ga-PSMA PET/CT images. Results: Median PSA prior 68Ga-PSMA PET/CT was 0.27ng/mL. All patients had a decrease in testosterone serum levels from median 2.95μg/l to 0.16μg/l following Degarelix injection. We observed an increase in the standardized uptake value (SUV) in PSMA-positive lymphogenous and osseous lesions in two patients following androgen deprivation. In another two patients, no PSMA positive signals were detected in either the first or the second scan. Conclusion: Our preliminary results of this feasibility assessment indicate a possible enhancing effect of PSMA-imaging induced by low-dose ADT. Despite several limitations and the small number of patients, this could be a new approach to improve staging by 68Ga-PSMA PET/CT in PCa patients with BCR after primary therapy. Further prospective studies with larger number of patients are needed to validate our findings.

During twenty years of Cisplatin-based therapy the face of nonseminomatous testicular germ cell tumors is still changing: an evaluation of presentation, management, predictive factors and survival

Purpose: To assess the changing presentation and treatment of nonseminomatous testicular germ cell tumors (NSGCT) and to investigate predictive factors for the status of metastasis at diagnosis and on relapse and death. Materials and Methods: Retrospective record review of 147 patients that underwent inguinal orchiectomy from 1987-2007. Follow-up data was available for 102 patients (median follow-up: 80 months (0-243); 96 patients alive). Results: Mean patients age increased (p = 0.015) and more patients were diagnosed in clinical stage I (CSI) (p = 0.040). The fraction of yolk sac (YS) elements inclined (p = 0.030) and pT2 tumors increased (p < 0.001). Retroperitoneal lymph node dissection (RPLND) declined whereas more patients were treated with chemotherapy (p < 0.001; p = 0.004). There was an increase in relapse free (RFS) and cancer specific survival (CSS) due to an improvement in patients with disseminated disease (p = 0.014; p < 0.001). The presence of YS and teratoma elements showed a reduction in the odds ratio (OR) for metastasis at diagnosis (p = 0.002, OR: 0.262; p = 0.009, OR: 0.428) whereas higher pT-stage was associated to their presence (p = 0.039). Patients with disseminated disease (CS > I) showed a declined CSS compared to CSI patients (p = 0.055). The presence of YS elements was associated to an improved RFS (p = 0.038). Conclusions: In our single institution study the face of NSGCT markedly changed over 20 years even after the introduction of Cisplatin-based chemotherapy. These changes were accompanied by an improvement in RFS and CSS. When dealing with NSGCT patients such observations now and in the future should be taken into account. .