Routine prostate biopsies not needed after cryotherapy if surveillance MRI is normal

Area of Science:

• Urology
• Oncology
• Radiology

Background:

• Ablative focal therapy (AFT) is an option for intermediate-risk prostate cancer (PCa).
• Post-treatment surveillance strategies, including MRI and biopsy, are crucial for monitoring recurrence.
• Distinguishing between MRI-visible (MRIv) and MRI-invisible (MRIi) cancers is important for risk stratification.

Purpose of the Study:

• To compare the detection rate and pathological features of MRIv versus MRIi prostate cancers.
• To evaluate the clinical significance of detected cancers after AFT.
• To assess the impact of MRI findings on surveillance strategies.

Main Methods:

• Retrospective analysis of 305 men undergoing primary partial gland cryoablation (PPGCA) for intermediate-risk PCa.
• Inclusion criteria: MRI PI-RADS 2-5, unilateral intermediate-risk disease, no gross extraprostatic extension, no contralateral significant disease, and ≥6 months follow-up.
• MRI performed at 6, 24, 42, and 60 months; biopsy indicated by evolving criteria; Gleason pattern 4 (GP4) defined clinically significant PCa recurrence (csPCaR).

Main Results:

• Of 665 post-treatment MRIs, 13.1% were positive for csPCaR.
• Clinically significant PCa detection rate (csPCaDR) was 43.5% for positive MRI and 10.6% for negative MRI.
• Median GP4 length was 2.6 mm for MRIv vs 0.6 mm for MRIi csPCaR (P=0.08).
• MRIi csPCaRs were more likely to be managed with continued active surveillance (44% vs 14% for MRIv, P=0.03).

Conclusions:

• MRI-invisible cancers after PPGCA are less likely to be clinically significant.
• Avoiding biopsies in most negative MRI cases can safely reduce surveillance costs and morbidity.
• This approach supports a more tailored surveillance strategy post-focal therapy.