Hemi-Ablative Prostate Brachytherapy

This clinical study will evaluate side effects, quality of life and cancer control in patients with prostate cancer diagnosed on only one side of the prostate gland. The diagnosis of unilateral prostate cancer will be made by means of a prostate transperineal template biopsy (TTB) and multiparametric magnetic resonance imaging (mpMRI). Patients will be treated with low dose rate brachytherapy, using permanent iodine seed implants.Treatment will be limited to the side of the gland where the cancer has been diagnosed and is therefore called "focal" brachytherapy. Prostate brachytherapy is usually applied to the whole prostate gland. After whole gland prostate brachytherapy urinary, bowel and sexual function may be affected. In this focal approach, the side effects will be evaluated by means of patient questionnaires.These will be repeated at various intervals after treatment.The results will be compared to the same questionnaires responded by patients who have undergone whole gland brachytherapy.Therefore an assessment can be made whether focal therapy produces fewer side effects than whole gland brachytherapy.The observation period will last for two years after treatment. A biopsy and mpMRI will be repeated after two years to evaluate prostate cancer control.