This is an open-label, non-controlled, non-randomized study to assess the safety and measure image-based absorbed dose of 177Lu-EB-PSMA-617 in patients with metastatic castration-resistant prostate cancer (mCRPC) who will undergo radioliagnd therapy using 177Lu-EB-PSMA-617. All patients underwent whole-body 68Ga-PSMA PET/CT for selection and accepted intravenous injection with single dose 0.80-1.1 GBq (21.5-30 mCi) of 177Lu-EB-PSMA-617 within one week, then monitored at 2, 24, 72, 120 and 168 h after 177Lu-EB-PSMA617 administration with serial whole body planar and SPECT/CT imaging.

Prostate cancer is the most frequent malignant tumor in men worldwide. Prostate-specific membrane antigen (PSMA), is a surface molecule specifically expressed by prostate tumors which was shown to be a valid target for radiotherapy. 177Lu-PSMA-617, a urea-based compound, provide an effective target for the treatment of metastatic castration-resistant prostate cancer. However, a major problem in the therapeutic use of 177Lu-PSMA-617 has been its short half-life and fast rate of clearance. This study was designed to investigate the safety, dosimetry and preliminary effects of 177Lu-EB-PSMA-617 in patients with metastatic castration-resistant prostate cancer.

Inclusion Criteria:

• All the patients had progressive metastatic castration-resistant prostate cancer that did not respond to androgen-suppression therapy and/or systemic chemotherapy. Distant metastases with high PSMA expression were confirmed on 68Ga-PSMA PET/CT within one week before the injection of 177Lu-EB-PSMA-617.

Exclusion Criteria:

• The exclusion criteria were a serum creatinine level of more than 150 μmol per liter, a hemoglobin level of less than 10.0 g/dl, a white-cell count of less than 4.0× 109/L, a platelet count of less than 100 × 109/L, a total bilirubin level of more than 3 times the upper limit of the normal range and a serum albumin level of more than 3.0 g per deciliter, cardiac insufficiency including carcinoid heart valve disease, a severe allergy or hypersensitivity to radiographic contrast material, claustrophobia, and pregnancy or breastfeeding.