Diagnostic performance of 18F-DCFPyL PET/CT for the initial staging of intermediate and high risk prostate cancer patients

479 Purpose: The aim of this study was to evaluate the performance of 18F-DCFPyL PET/CT for initial staging of intermediate and high-risk prostate cancer (PC) patients. Methods: A total of42 intermediate and high risk PC patients were subjected to 18F-DCFPyL PET/CT for initial staging between September 2017 and June 2019 after the sign of written informed consent. 18F-DCFPyL was produced on-cite in Shanghai Xinhua Hospital. The multi parameter MRI (mp-MRI) and whole-body bone scan (BS) were done within 2 weeks before the 18F-DCFPyL PET/CT. The sensitivity (SEN), specificity (SPE), positive prognostic value (PPV), negative prognostic value (NPV) and accuracy (ACU) of 18F-DCFPyL PET/CT for initial staging was evaluate. Results were compared to findings on mp-MRI and BS. Results: 1. In 42 PC patients for initial staging, 23 patients had received radical prostatectomy and their pathological results were obtained. Among them, 7 cases were verified T2 and 16 cases were verified T3 or T4. The SEN, SPE, PPV, NPV and ACU of 18F-DCFPyL PET/CT in diagnosing T stage was 100%, 75.0%, 88.2%, 100% and 91.3% respectively. By pelvic mp-MRI, it was 60.0%, 87.5%, 90.0%, 46.2% and 65.2% respectively. 2. It was verified by the pathological results that there were 19 regional lymph nodes were metastatic within 218 resected regional lymph nodes among 23 patients who were received pelvic lymph node dissection. The SEN, SPE, PPV, NPV and ACU of 18F-DCFPyL PET/CT in diagnosing regional lymph node metastasis was 89.5%, 98.0%, 81.0%, 99.0% and 97.2% respectively. By pelvic mp-MRI, it was 42.1%, 100%, 100%, 94.8% and 95.0% respectively. 3. Among 42 PC patients, 16 cases were found to be bone metastatic with 64 bone lesions totally. The SEN, SPE, PPV, NPV and ACU of 18F-DCFPyL PET/CT in diagnosing bone metastasis was 100%, 96.2%, 94.1%, 100% and 97.6% respectively. By BS, it was 75%, 88.5%, 80%, 85.2% and 83.3% respectively. 4. Initial staging was up-staged in 12 cases (28.6%) and down-staged in 3 cases (7.1%) by 18F-DCFPyL PET/CT in 42 cases of intermediate and high risk PC. Conclusions: 18F-DCFPyL PET/CT has higher sensitivity and accuracy than conventional imaging in the initial staging of the intermediate and high risk PC patients and change the staging by conventional imaging (CI). Thus, it may improve the therapeutic planning of the PC patients.