Univariate analysis was performed for the following variables: age, IIEF score and IIEF classes before PB, existence of morning erection, concern about sexuality, neoadjuvant hormonal therapy, pre-treatment PSA level, IPSS score and prostate volume, history of diabetes, vascular disorders and obesity, contraindication to surgery, brachytherapy parameters D90, V100, V150, U30, RV160, number of implanted seeds and number of implanted needles. This evidence concerns the gene KLK3 and obesity due to melanocortin 4 receptor deficiency.