Validation of PI-RADS version 2 in transition zone lesions for the detection of prostate cancer
© RSNA, 2018. Purpose: To determine the association between Prostate Imaging Reporting and Data System (PI-RADS) version 2 scores and prostate cancer (PCa) in a cohort of patients undergoing biopsy of transition zone (TZ) lesions. Materials and Methods: A total of 634 TZ lesions in 457 patients were identified from a prospectively maintained database of consecutive patients undergoing prostate magnetic resonance imaging. Prostate lesions were retrospectively categorized with the PI-RADS version 2 system by two readers in consensus who were blinded to histopathologic findings. The proportion of cancer detection for all PCa and for clinically important PCa (Gleason score 3+4) for each PI-RADS version 2 category was determined. The performance of PI-RADS version 2 in cancer detection was evaluated. Results: For PI-RADS category 2 lesions, the overall proportion of cancers was 4% (one of 25), without any clinically important cancer. For PI-RADS category 3, 4, and 5 lesions, the overall proportion of cancers was 22.2% (78 of 352), 39.1% (43 of 110), and 87.8% (129 of 147), respectively, and the proportion of clinically important cancers was 11.1% (39 of 352), 29.1% (32 of 110), and 77.6% (114 of 147), respectively. Higher PI-RADS version 2 scores were associated with increasing likelihood of the presence of clinically important PCa (P , .001). Differences were found in the percentage of cancers in the PI-RADS category between PI-RADS 3 and those upgraded to PI-RADS 4 based on diffusion-weighted imaging for clinically important cancers (proportion for clinically important cancers for PI-RADS 3 and PI-RADS 3+1 were 11.1% [39 of 352] and 30.8% [28 of 91], respectively; P < .001). Conclusion: Higher PI-RADS version 2 scores are associated with a higher proportion of clinically important cancers in the TZ. PIRADS category 2 lesions rarely yield PCa, and their presence does not justify targeted biopsy.
Thai, J., Narayanan, H., George, A., Siddiqui, M., Shah, P., Mertan, F., Merino, M., Pinto, P., Choyke, P., Wood, B., & Turkbey, B. (2018). Validation of PI-RADS version 2 in transition zone lesions for the detection of prostate cancer. Radiology, 288 (2). http://dx.doi.org/10.1148/radiol.2018170425