To assess the outcome of radiotherapy (RT) to all PSMA ligand positive metastases for patients with castrate-resistant prostate cancer (mCRPC).
A total of 42 patients developed oligometastatic mCRPC and received PSMA PET-guided RT of all metastases. The main outcome parameters were biochemical progression-free survival (bPFS), and second-line systemic treatment free survival (SST-FS).
A total of 141 PSMA ligand-positive metastases were irradiated. The median follow-up time was 39.0 months (12-58 months). During the follow-up five out of 42 (11.9%) patients died of progressive mPCa. Five out of 42 (11.9%) patients showed no biochemical responses and presented with a PSA level ≥10% of the baseline PSA at first PSA level measurement after RT and were classified as non-responders. The median PSA level before RT was 4.79 ng/mL (range, 0.4-46.1), which decreased significantly to a median PSA nadir level of 0.39 ng/mL (range, <0.07-32.8; p=0.002). The median PSA level at biochemical progression after PSMA ligand-based RT was 2.75 ng/mL (range, 0.27-53.0; p=0.24) and was not significantly different (p=0.29) from the median PSA level (4.79 ng/mL, range, 0.4-46.1) before the PSMA ligand-based RT. The median bPFS was 12.0 months after PSMA ligand PET-based RT (95% CI, 11.2-15.8) and the median SST-FS was 15.0 months (95% CI, 14.0-21.5).
In well-informed and closely followed-up patients, PSMA PET-guided RT represents a viable treatment option for patients with oligometastatic mCRPC to delay further systemic therapies.
Frontiers in oncology. 2021 Apr 19*** epublish ***
Christoph Henkenberens, Thorsten Derlin, Frank Bengel, Tobias L Ross, Markus A Kuczyk, Frank A Giordano, Gustavo R Sarria, Leonard Christopher Schmeel, Hans Christiansen, Christoph A J von Klot
Department of Radiotherapy and Special Oncology, Hannover Medical School, Hannover, Germany., Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany., Department of Urology and Urologic Oncology, Hannover Medical School, Hannover, Germany., Department of Radiation Oncology, University Hospital Bonn, Bonn, Germany.