Focal Therapy for Prostate Cancer: Available Technologies, Patient Selection, Follow-Up Protocols and Reported Outcomes.

Abstract

The first description of focal therapy (FT) for prostate cancer was by Gary Onik when he described the use of hemigland cryoablation. Currently, focal therapy is performed using different energy modalities: (1) Cryotherapy, (2) irreversible electroporation, (3) high-intensity focused ultrasound, (4) transurethral ultrasound ablation, (5) focal laser therapy, (6) bipolar radiofrequency ablation and (7) photodynamic therapy. Intermediate-risk prostate cancer with an index lesion seen on prostate magnetic resonance imaging, with negative or low-grade cancer on systematic biopsies is appropriate candidate for focal therapy. Currently, most follow-up protocols include prostate-specific antigen (PSA) measurement every three months during the first year and every six months thereafter, conducting multiparametric magnetic resonance imaging (mpMRI) scans at six months, twelve months, and then annually, as well as performing targeted biopsies of the ablation zone along with systematic biopsies between six to twelve months post-treatment. In general, FT rarely results in significant morbidity and appears to have a minimal effect on quality of life, however long-term oncological outcomes require further assessment. The heterogeneity in technologies, patient selection criteria, follow-up protocols and lack of high-level evidence for focal therapy present the biggest challenges in recommending this treatment modality as a standard management option for selecting patients. The aim of this article is to discuss the challenges surrounding patient selection and to review the different focal therapy modalities and follow-up strategies after treatment.