Men newly diagnosed with low volume oligometastatic prostate cancer defined as fewer than 5 bone metastases and/or non regional lymph node involvement who agree to treatment of the primary cancer with radiation will be randomized between standard moderately hypofractionated external radiotherapy (5500 centiGray/20 fractions as per Stampede trial) and one of 3 alternatives: stereotactic body radiotherapy (SABR) to deliver 36 Gy/5 fractions, or low dose rate Iodine 125 permanent seed implant or a single high dose rate temporary implant. The trial will take place in 4 regional cancer centers of British Columbia Cancer Agency, with each center choosing their preferred alternative to 5500/20. To achieve 4 equally sized treatment arms, each randomization is weighted 3:1 for 42 patients in each arm and 168 total accrual. The primary endpoint is urinary quality of life as assessed by the International Prostate Symptom Score (IPSS) . As the typical acute symptoms from each of these radiation modalities has a unique time course, assessments are done at 6 different points during the first 2 years. Secondary endpoints are global quality of life as assessed by Expanded Prostate Cancer Index (EPIC) urinary, bowel and sexual scores, progression free survival, overall survival and cost effectiveness.
