Reevaluatıng Pı-rads 3 Lesıons Upgraded to 4: The Emergence of a New Subgroup?

Objectives The study aims to evaluate PI-RADS 4 lesions, including those with primary diffusion restriction (diffusion-weighted imaging score 4) and those upgraded from PI-RADS 3 due to positive dynamic contrast-enhanced findings, and to compare outcomes between these groups while also assessing cancer detection rates and prostatitis between upgraded cases and PI-RADS 3 lesions. Methods In this single-center cohort study, peripheral zone lesions classified as PI-RADS 3 and 4 by multiparametric magnetic resonance imaging (MRI) and biopsied via MRI/Transrectal ultrasound-guided targeted biopsy were analyzed. Results Of 420 peripheral zone lesions from 272 patients, 202 were PI-RADS 3, 81 PI-RADS 3 + 1, and 137 PI-RADS 4. Cancer detection rates significantly differed between PI-RADS 3 + 1 and PI-RADS 4 (38.3% vs 73% for overall cancer; 6.2% vs 30.7% for clinically significant cancer, p < 0.001). PI-RADS 3 + 1 lesions had significantly higher cancer detection rates than PI-RADS 3 lesions (38.3% vs 19.8%, p = 0.001). Prostatitis was significantly more prevalent in PI-RADS 3 (34.7%) and PI-RADS 3 + 1 (29.6%) than in PI-RADS 4 (10.9%) lesions (p < 0.001). Conclusion PI-RADS 3 + 1 lesions show significantly different cancer detection rates from both PI-RADS 3 and 4, suggesting they should be managed as a distinct entity. Higher prevalence of prostatitis in PI-RADS 3 + 1 lesions indicates that clinical evaluation for inflammatory conditions may help reduce unnecessary biopsies in this subgroup. Advances in Knowledge PI-RADS 3 + 1 lesions show higher cancer detection than PI-RADS 3 but lower than PI-RADS 4, and are more frequently associated with prostatitis than PI-RADS 4. These findings support individualized management to avoid unnecessary biopsies.