i. Up to 5 metastatic sites ii. ≤ 4 tumours within any given organ system, excluding brain and liver (e.g. up to 4 bone metastases, or 4 lung metastases) iii. All sites of disease must be amenable to SBRT with no history of the metastases being irradiated; iv. In the case of a suspicious lesion in an unusual location such as lung or thoracic lymph nodes (without other abdominal lymph nodes), a biopsy should confirm prostate cancer origin.