Clinical outcome of PSMA-guided radiotherapy for patients with oligorecurrent prostate cancer
Stefan A. Koerber, Katharina Sprute, Clemens Kratochwil, Erik Winter, Matthias F. Haefner, Sonja Katayama, Ingmar Schlampp, Klaus Herfarth, Klaus Kopka, Ali Afshar‐Oromieh, Stefanie Zschaebitz, Tim Holland‐Letz, Peter L. Choyke, Dirk Jaeger, Markus Hohenfellner, Uwe Haberkorn, Jürgen Debus, Frederik L. Giesel
Abstract
PURPOSE: First-line treatment of patients with recurrent, metastatic prostate cancer involves hormone therapy with or without additional systemic therapies. Prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) allows the detection of oligometastatic disease that may be amenable to image-guided radiotherapy. The current study classifies the type and localization of metastases and the clinical outcome of PSMA-PET/CT-guided radiotherapy to selected metastases. MATERIALS AND METHODS: Between 2011 and 2019, 86 patients with recurrent, oligometastatic prostate carcinoma were identified by PSMA-PET/CT and were treated with image-guided radiotherapy of their metastases. Sites of relapse were characterized, and the primary endpoint overall survival (OS), biochemical progression-free survival (bPFS), and androgen deprivation therapy (ADT)-free survival were tabulated. RESULTS: In total, 37% of the metastases were bone metastases, 48% were pelvic nodal metastases, and 15% were nodal metastases outside of the pelvis. After PSMA-guided radiotherapy, a biochemical response was detected in 83% of the cohort. A statistically significant decrease in the standard uptake value (SUV) was seen in irradiated metastases. After a median follow-up of 26 months, the 3-year OS and bPFS were 84% and 55%, respectively. The median time of ADT-free survival was 13.5 months. A better clinical outcome was observed for patients receiving concomitant ADT or more than 24 fractions of radiation. CONCLUSION: PSMA-guided radiotherapy is a promising therapeutic approach with excellent infield control for men with oligorecurrent prostate carcinoma. However, prospective, randomized trials are necessary to determine if this approach confers a survival advantage.