To evaluate the diagnostic performance of the Prostate Imaging after Focal Ablation (PI-FAB) score on multiparametric MRI in combination with volume-adjusted PSA density (vaPSA-D, derived from volumetrically assessed residual vital prostate tissue) for detecting in-field recurrence after HIFU ablation of localized prostate cancer.
In this retrospective single-center study, 117 men treated with HIFU underwent follow-up mpMRI and prostate biopsies at 6 (n = 99), 12 (n = 74), and 36 (n = 52) months. PI-FAB scores and vaPSA-D were assessed independently. Diagnostic performance was evaluated using biopsy-based histopathology as the reference standard.
PI-FAB demonstrated good diagnostic performance, particularly at 36 months (AUC 0.92). vaPSA-D showed increasing accuracy over time (AUC 0.64, 0.82, 0.84 at 6, 12, and 36 months; overall 0.78), outperforming PI-FAB at 12 months. Integrating vaPSA-D into PI-FAB subgroups significantly enhanced recurrence assessment: PI-FAB 1: sensitivity/specificity 75%/79% (threshold 0.14 ng/ml); PI-FAB ≥ 2: sensitivity/specificity 65%/85% (0.18 ng/ml); PI-FAB 3: sensitivity/specificity 67%/90% (0.18 ng/ml).
Both PI-FAB and vaPSA-D provide reliable recurrence assessment after HIFU, with complementary strengths: PI-FAB performs best at later follow-up stages, whereas vaPSA-D maintains high sensitivity throughout. Their combined application offers the most accurate evaluation of post-HIFU recurrence and may help reduce unnecessary biopsies.
European journal of radiology open. 2026 Jun 25*** epublish ***
Clara Elsner, Antonia M Pausch, Toni Rabadi, Tabea Borde, Niels J Rupp, Daniel Eberli, Ashkan Mortezavi, Priska Heinz, Ulrike Held, Andreas M Hötker
Diagnostic and Interventional Radiology, University Hospital Zurich, Rämistrasse 100, Zurich 8091, Switzerland., Department of Pathology and Molecular Pathology, University Hospital Zurich, Schmelzbergstrasse 12, Zurich 8091, Switzerland., Department of Urology, University Hospital Zurich, Frauenklinikstrasse 10, Zurich 8091, Switzerland., Epidemiology, Biostatistics and Prevention Institute (EBPI), Department of Biostatistics, University of Zurich, Hirschengraben 84, Zurich 8001, Switzerland.