¹⁷⁷Lu-PSMA With Olaparib Radiosensitization Potentiates Response and Toxicity in Extensive Castration-Resistant Metastatic Prostate cancer

A patient with widespread intensely prostate-specific membrane antigen–expressing, BRCA gene mutation–positive bone metastases at the time of prostate cancer diagnosis had progressed on multiple lines of standard therapy. He received ¹⁷⁷Lu–prostate-specific membrane antigen 8.5 GBq augmented by a short course of olaparib radiosensitization and achieved 90% decrease in serum PSA level after a single treatment. His tumor response was much better than expected by predictive dosimetry. However, his marrow radiotoxicity was worse than anticipated and required hospitalization. This suggests radiosensitizing agents to be a double-edged sword that must be carefully considered and balanced during activity prescription.