Prostate Cancer Staging MRI: Prospective Value of Structured Reports With Defined Extraprostatic Extension Grading System

Objective: – Accurate preoperative staging of extraprostatic extension (EPE) in prostate cancer using prostate MRI is essential for treatment planning but remains variable in practice. We evaluate the diagnostic accuracy and reporting clarity of a structured MRI reporting template and compare its performance with prior similar systems and subjective staging reports. Materials and Methods: – In this retrospective study, 621 consecutive men who underwent 3T prostate MRI before radical prostatectomy between 2013 and 2021 were evaluated. Of these, 183 prospectively interpreted MRI reports utilized a structured staging template incorporating a 7-point EPE scoring system based on a previously published model, modified to include additional intermediate-length capsular abutment categories. The remaining 438 reports used subjective staging. Report clarity was analyzed for the inclusion of EPE assessment and likelihood. Radical prostatectomy histopathology served as the reference standard. Diagnostic accuracy for EPE detection was assessed using the area under the receiver operating characteristic curve (AUC), and report clarity was analyzed for inclusion of EPE assessment and likelihood. Results: – Structured reports were significantly more likely than subjective reports to describe EPE likelihood [100% vs. 52%, (P < 0.001)]. The structured EPE template yielded progressively higher positive predictive value with higher scores, in line with corresponding standardized verbal assessments of EPE probability, yielding an EPE prediction AUC of 0.76 (95% CI: 0.69-0.83). Conclusions: – Structured prostate MRI reports prospectively interpreted using a structured EPE grading system significantly enhanced staging communication clarity over subjective interpretations. The structured template maintained predictable diagnostic accuracy similar to prior retrospective studies. Structured staging report templates can be successfully integrated into clinical practice and improve interdisciplinary communication, offering a scalable and reproducible approach to standardizing prostate MRI staging.