Evaluation of Biochemically Recurrent Prostate Cancer Using the Prostate Imaging for Recurrence Reporting Systems

Motivation: PI-RR assessment is not universally validated and has not yet been extensively studied for diagnostic accuracy and interreader variability. Goal(s): To evaluate the performance of PI-RR for detecting local recurrence in PCa patients with BCR after radiation therapy (RT) or radical prostatectomy (RP). Approach: 110 patients who underwent MRI and FDG PET/CT were included. A group of four radiologists with varying experience was recruited for recurrence evaluation. Results: With a PI-RR of 3 as a cutoff, the AUCs ranged from 0.56 to 0.83 after RT and 0.73 to 0.90 after RP across the four readers. The ICC values were 0.54 and 0.68, respectively. Impact: PI-RR may serve as a clinical guide to improve the management of recurrent PCa by achieving good diagnostic performance and interreader agreement.