Prostate cancer is the most prevalent form of cancer in men in Western countries. Currently, owing to a lack of reliable techniques for prostate cancer imaging, treatment options are often restricted to radical treatments, which carry significant risks of permanent side-effects, such as incontinence or impotence and bowel issues. Therefore, focal therapy in prostates has been proposed as an alternative. Magin et al. [1] started in 1980 with thermal destruction of the canine prostate by high-intensity microwaves. Since then, a variety of focal ablation techniques have been introduced to the minimal invasive treatment of prostate cancer. These techniques include focal brachytherapy, cryoablation, high-intensity focused ultrasound (HIFU), laser ablation therapy, radiofrequency ablation, photodynamic therapy (PDT) and irreversible electroporation (IRE). The different ablation mechanisms are explained in Fig. 1. In all of the aforementioned therapies, there is a scarcity of long-term data on the efficacy and on metastasis-free, prostate cancer-specific or overall survival. The quality of the evidence is low to moderate, with no study yielding a level of evidence higher than 2b [2& ]. However, whole-gland cryosurgery has been accepted as a true therapeutic alternative by the guidelines of the American Urological Association (AUA), despite this lack of high-level evidence from prospective randomized trials to support the role of cryosurgery over the other therapeutic options [3]. This is caused by the acceptable health-related quality of life outcomes and low costs compared with alternative local treatment options and because of the short-term PSA relapse-free survival outcomes after whole-gland cryoablation [4]. HIFU is considered an experimental treatment by the AUA and has potentially the same therapeutic efficacy as established surgical and nonsurgical options, as the additional advantage of reduced therapy-associated morbidity [5]. No other focal treatment is considered as a therapeutic or experimental alternative so the major unanswered question remains: What is still needed to make focal therapy an accepted segment of standard therapy?
