MRI accuracy for recurrence after partial gland ablation with HIFU for localized prostate cancer. A systematic review and meta-analysis

Background

Prostate cancer remains the most frequently diagnosed cancer among men. High-Intensity Focused Ultrasound (HIFU) has emerged as a thermal ablative technique for partial-gland-ablation (PGA), aiming to minimize collateral damage while maximizing tumor control. Monitoring after HIFU PGA relies on serial PSA testing, multiparametric-MRI, and biopsies. The diagnostic accuracy of MRI for clinically-significant cancer(csPCa) recurrence is challenging.

Objective

This systematic review and meta-analysis aim to evaluate the accuracy of MRI in detecting early recurrence of localized prostate cancer following HIFU PGA.

Methods

Adhering to PRISMA guidelines, a comprehensive literature search was conducted until May 8^th 2024 using MEDLINE and Scopus. The inclusion criteria encompassed randomized controlled trials and cohort studies involving men diagnosed with localized prostate cancer who had as primary treatment HIFU PGA. The primary outcome measures included the sensitivity, specificity, positive-predictive value (PPV), and negative-predictive value (NPV) of MRI for csPCa(ISUP ≥ 2) based on biopsy results. We pooled data from studies with sufficient csPCa and csPCa-free patients (≥5) post HIFU for statistical analysis.

Results

Fifteen studies meet the inclusion criteria, encompassing 1093 patients and 12 studies were eligible for meta-analysis. MRI sensitivity in detecting clinically-significant prostate cancer (csPCa) recurrence post HIFU PGA varied widely (0–89%), with a pooled sensitivity of 0.52 (95% CI:0.36–0.68). Specificity ranged from 44% to 100%, with a pooled specificity of 0.81 (95% CI:0.68–0.91). The pooled NPV was 0.82 (95% CI:0.72–0.90), and the pooled PPV was 0.50 (95% CI:0.35–0.65). Three studies reported in-field diagnostic performance with sensitivities ranging from 0.42 to 0.80 and specificities from 0.45 to 0.97.

Conclusion

MRI accuracy for clinically-significant recurrence after partial gland ablation with HIFU for localized prostate cancer shows low diagnostic performance in the treated lobe with pooled sensitivity of 0.52 (95% CI:0.36–0.68) and specificity of 0.81 (95% CI:0.68–0.91). Limits of this review include the low number of studies reporting about site of recurrence in or out of the treated lobe.