In other studies where shorter and more intense courses of radiation have been given using similar high-precision techniques, the side effects of treatment have indeed been no worse than the usual techniques. Over the last 7 years, Sunnybrook researchers have treated over three hundred prostate cancer patients on various research protocols with SABR. In those protocols, patients received 5 SBRT treatments over 29 days and this is currently being compared to 5 SBRT treatments over 11 days in an ongoing randomized study. In the United States, several groups have investigated the 5 SBRT approach in 11 days or less and early findings suggest a good tolerance.