The Use of PI-FAB Score in Evaluating mpMRI After Focal Ablation of Prostate Cancer: Is It Reliable? Inter-Reader Agreement in a Tertiary Care Referral University Hospital
by
, , , , , ,
Elena Bertelli
1,*,†
,
Michele Vizzi
1,†
,
Martina Legato
1,
Rossella Nicoletti
2,
Sebastiano Paolucci
3,
Ron Ruzga
1,
Simona Giovannelli
1,
Francesco Sessa
2,
Sergio Serni
2,4,
Lorenzo Masieri
2,4,
Riccardo Campi
2,4,
Emanuele Neri
5,
Simone Agostini
1 and
Vittorio Miele
1 1
Department of Radiology, Careggi University Hospital, Largo Brambilla 3, 50134 Florence, Italy
2
Unit of Urological Minimally Invasive, Robotic Surgery and Kidney Transplantation, Careggi University Hospital, Largo Brambilla 3, 50134 Florence, Italy
3
Department of Health Physics, Careggi University Hospital, Largo Brambilla 3, 50134 Florence, Italy
4
Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
5
Academic Radiology, Department of Translational Research, University of Pisa, Via Roma, 67, 56126 Pisa, Italy
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Cancers 2025, 17(6), 1031; https://doi.org/10.3390/cancers17061031
Submission received: 12 February 2025
/
Revised: 15 March 2025
/
Accepted: 18 March 2025
/
Published: 20 March 2025
(This article belongs to the Special Issue Molecular Imaging in Oncology: Recent Advances)
Simple Summary
Focal therapies are very promising techniques for prostate cancer treatment, but their use in post-therapy MRI assessment, both in image acquisition and reporting, requires standardization. Prostate Imaging after Focal Ablation (PI-FAB) scoring, first described in May 2023, is a new scoring system for interpreting prostate multiparametric magnetic resonance imaging (mpMRI) results after focal therapies. The aim of our study was to assess the inter-reader agreement of PI-FAB scores among radiologists in a single large cohort of patients treated with focal therapy (in particular, high intensity focused ultrasound, HIFU) in a tertiary care referral University Hospital. To our knowledge, only two studies have evaluated the inter-reader agreement of PI-FAB scoring so far. In our experience, this new score significantly improves the inter-reader agreement of radiologists with different levels of experience. Furthermore, HIFU seems to be a very promising tool for the treatment of selected prostate cancer patients.
Abstract
Background/Purpose: to assess the inter-reader agreement of the PIFAB (Prostate Imaging after Focal Ablation) score, a new MRI-based standardized system for evaluating post-focal therapy prostate mpMRI, among radiologists in a single large cohort of patients treated with focal therapy (HIFU) in a tertiary care referral University Hospital. Methods: In total, 68 consecutive patients who underwent HIFU were included in this single-center retrospective observational study. A total of 109 post-HIFU follow-up mpMRIs were evaluated by three radiologists with varying levels of experience (12, 8, and 3 years, respectively). All patients underwent their first follow-up mpMRI at 6 months post-treatment, with 30 patients receiving additional evaluations at 18 months and 11 at 30 months. Results: The patients had a mean age of 70.6 ± 8.31 years, a mean pre-treatment PSA (prostate-specific antigen) of 7.85 ± 1.21 ng/mL, and a mean post-treatment PSA of 4.64 ± 4.2 ng/mL. The inter-reader agreement for PI-FAB among the three radiologists showed a Gwet’s AC2 value of 0.941 (95% confidence interval: 0.904–0.978, p < 0.0001). For the most experienced radiologist, at the 6-month follow-up 64 (94.14%) patients were scored as PI-FAB 1, 1 (1.47%) as PI-FAB 2, and 3 (4.41%) as PI-FAB 3. At the 18-month and 30-month follow-ups all patients were scored as PI-FAB 1 (no suspicion of recurrence). Conclusions: Our study demonstrates excellent inter-reader agreement among radiologists with varying levels of experience, confirming that the PI-FAB score is highly reproducible when evaluating post-treatment mpMRI scans. The low rate of PI-FAB 2 and PI-FAB 3 lesions observed at the first follow-up, coupled with the absence of significant recurrence in subsequent evaluations, suggests that HIFU is a reliable technique for prostate cancer treatment in selected patients.
Keywords:
PI-FAB; focal therapy; HIFU; prostate cancer; mpMRI
