Additional Local Therapy for Liver Metastases in Patients with Metastatic Castration-Resistant Prostate Cancer Receiving Systemic PSMA-Targeted Therapy

The aim of this study was to evaluate the efficacy of Lu-prostate-specific membrane antigen (PSMA)-617 ( Lu-PSMA) and selective internal radiation therapy (SIRT) for the treatment of liver metastases of castration-resistant prostate cancer. Safety and survival of patients with metastatic castration-resistant prostate cancer and liver metastases assigned to Lu-PSMA alone ( = 31) or in combination with SIRT ( = 5) were retrospectively analyzed. Additionally, a subgroup ( = 10) was analyzed using morphologic and molecular response criteria. Median estimated survival was 5.7 mo for Lu-PSMA alone and 8.4 mo for combined sequential Lu-PSMA and SIRT. Lu-PSMA achieved discordant therapy responses with both regressive and progressive liver metastases in the same patient (best vs. worst responding metastases per patient: -35% vs. +63% diameter change; < 0.05). SIRT was superior to Lu-PSMA for the treatment of liver metastases (0% vs. 56% progression). The combination of Lu-PSMA and SIRT is efficient and feasible for the treatment of advanced prostate cancer. Lu-PSMA alone seems to have limited response rates in the treatment of liver metastases.