RecruitingPhase 1Radiation therapyUltra-fractionated Radiotherapy for Rectal CancerThe rationale of this clinical trial is to assess the feasibility of selective non-operative management for locally advanced rectal cancer using dose-escalated ultra-fractionated short course radiation therapy interdigitated with chemotherapy. We believe delivering short course radiotherapy over a prolonged interval, at escalated doses and with concurrent chemotherapy may be feasible and allow for improved clinical response.