Surveillance after prostate focal therapy

Introduction: Long-term outcomes from large cohorts are not yet available upon which to base recommended follow-up protocols after prostate focal therapy. This is an updated summary of a 2015 SIU-ICUD review of the best available current evidence and expert consensus on guidelines for surveillance after prostate focal therapy.

Methods: We performed a systematic search of the PubMed, Cochrane and Embase databases to identify studies where primary prostate focal therapy was performed to treat prostate cancer.

Results: Multiparametric magnetic resonance imaging (mpMRI) should be performed at 3-6 months, 12-24 months and at 5 years after focal therapy. Targeted biopsy of the treated zone should be performed at 3-6 months and fusion biopsy of any suspicious lesion seen on mpMRI. Additionally, a systematic biopsy should be performed at 12-24 months and again at 5 years. In histological diagnosis, characteristic changes of each treatment modality should be noted and in indeterminate situations various immunohistochemical molecular markers can be helpful. Small volume 3 + 3 (Prognostic grade group [PGG] 1) or very small volume (< 0.2 cc or < 7 mm diameter) 3 + 4 (PGG 2) are acceptable in the treated zone at longitudinal follow-up. Significant volumes of 3 + 4 (PGG 2) or more within the treated zone should be treated. Any clinically significant cancer subsequently arising within the non-treated zone should be treated and handled in the same way as any de novo prostate cancer. Patients should be counseled regarding whole-gland and focal approaches to treating these new foci where appropriate. One or two well-delineated foci of significant cancer can be ablated to keep the patient in the 'active surveillance pool'. More extensive disease should be treated with traditional whole-gland techniques.

Conclusion: Focal therapy remains a nascent field largely comprising single center cohorts with little long-term data. Our current post-focal therapy surveillance consensus recommendations represent the synthesis of the best available evidence as well as expert opinion. Further work is necessary to define the most oncologically safe and cost-effective way of following patients after focal therapy.