Focal therapy (FT) for intermediate-risk, clinically localized unifocal prostate cancer (PCa) offers a tissue-sparing alternative to radical treatment with fewer adverse effects. However, post-FT surveillance remains challenging due to difficulty distinguishing fibrosis from residual tumor on multiparametric MRI (mpMRI). The PI-FAB and TARGET scoring systems were proposed to improve detection of clinically significant PCa (cs-PCa) recurrence. This study compares their diagnostic performance and real-world validation.
We retrospectively reviewed 111 men treated with FT (HIFU or cryotherapy) between 2019 and 2023, 31 of which met criteria for analysis with post-FT mpMRI and targeted/systematic prostate biopsies. Post-treatment mpMRI were scored using PI-FAB and TARGET systems. The primary outcome was detection of in-field cs-PCa (Grade Group ≥ 2) recurrence on biopsy. Diagnostic accuracy, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), was calculated for each scoring system.
The mean age was 67 years; 75% received HIFU and 25% cryotherapy. Eight men (26%) had cs-PCa on post-treatment biopsy, with 5 (16%) in-field recurrences. The PI-FAB and TARGET systems showed modest accuracy for in-field cs-PCa with AUCs of 0.66 and 0.62, respectively. Sensitivity was 60% (PI-FAB) and 40% (TARGET), specificity was 73% and 85%, PPV was 30% and 33%, and NPV was 90% and 88%, respectively.
The PI-FAB and TARGET mpMRI scoring systems demonstrate limited sensitivity but high NPV in detecting in-field cs-PCa recurrence after FT. These results highlight the limitations of current mpMRI interpretation protocols post-FT and the need for improved surveillance tools to guide biopsy decisions.
Clinical genitourinary cancer. 2026 Feb 18 [Epub ahead of print]
Denzel Zhu, Kamil Malshy, Zijing Cheng, Kaela Mali, Michael Shen, Jathin Bandari, Gary M Hollenberg, Eric P Weinberg, Thomas P Frye
Department of Urology, University of Rochester Medical Center, Rochester, NY., University of Rochester School of Medicine and Dentistry, Rochester, NY., Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY., Department of Urology, University of Rochester Medical Center, Rochester, NY. Electronic address: .