Focal brachytherapy for selected low-risk prostate cancers: A pilot study

PurposeTo evaluate the feasibility and the early toxicity of focal brachytherapy in highly selected localized prostate cancer patients.Methods and MaterialsTwenty-one patients underwent a focal brachytherapy between February 2010 and March 2012, representing 3.7% of the cases treated by our group during this period. Patient selection was based on (at least) two series of prostate biopsies and a high-resolution MRI. Only patients with very limited and localized tumors, according to strict criteria, were selected for the procedure. The technique used a real-time procedure with the implantation of free ¹²⁵I seeds and dynamic dose calculation. The prescribed dose for the focal volume was 145 Gy.ResultsThe treated volume corresponded to a mean value of 34% of the total prostatic volume (range, 20–48%). For the focal volume, the mean D₉₀ and V₁₀₀ was 183.2 Gy (range, 176–188 Gy) and 99.3% (range, 98.8–100%), respectively. The technique was performed in an hour and a half. When compared with a previous cohort treated by whole-prostate brachytherapy, urinary toxicity (International Prostate Symptom Score) was borderline reduced (p = 0.04) at 6 months only, whereas the recovery of the International Index of Erectile Function 5 was better (p = 0.014). The International Continence Score was nil in almost all cases as well as rectal toxicity.ConclusionFocal treatment by brachytherapy is easily feasible with little acute toxicity. Further investigation is needed to assess the results in terms of tumor control and long-term toxicity.