External validation of inter-reader reliability of the Prostate Imaging after Focal Ablation (PI-FAB) scoring system following focal cryoablation and focal high-intensity focused ultrasound
摘要
The efficacy of focal therapy (FT) has improved with the use of multiparametric MRI (mpMRI) for lesion identification, though standardized mpMRI reporting post-FT is lacking. The Prostate Imaging after Focal Ablation (PI-FAB) scoring system was recently introduced to standardize mpMRI interpretation for local recurrence post-FT. This study evaluates the diagnostic performance and inter-reader reliability of PI-FAB following cryoablation and high-intensity focused ultrasound (HIFU) modalities.
Materials and methodsThis retrospective, single-institution study included all patients treated with FT from 2007 to 2023 with available follow-up mpMRI and subsequent prostate biopsy. Three fellowship-trained radiologists scored these images using the PI-FAB system. The primary objective was inter-reader agreeability of PI-FAB scores, and the secondary objective assessed performance metrics, including sensitivity, specificity, positive predictive and negative predictive value.
Results91 patients with 113 mpMRI exams (95 post-cryotherapy; 18 post-HIFU) were reviewed. There was substantial agreement between the readers (Fleiss’ Kappa (κ): 0.71, p < 0.001; Gwet AC2: 0.70, p < 0.03). A PI-FAB score 3 had a significant ability to rule-in csPCa with high specificity (88%, 86%, and 93% per reader, respectively), and PI-FAB score 1 had high sensitivity to rule out csPCa (88%, 78%, and 84% per reader, respectively) in surveillance imaging (14–16 months median follow-up).
ConclusionsOur study suggests that the PI-FAB scoring system can be effectively used to evaluate mpMRI recurrence post-FT, with substantial inter-reader reliability and high specificity for predicting in-field clinically significant prostate cancer recurrence post-cryotherapy and HIFU. Larger, multi-institutional studies are essential to confirm PI-FAB’s utility in clinical practice.
Key Points