RecruitingPhase 2Radiation therapyMR-Adaptive Radiation Therapy for Anal Cancer With EScalated-Treatment in a Risk-Optimized ApproachThe proposed study is a phase II, single arm, open-label trial of MR-guided radiation therapy (RT) with risk stratified RT dose selection in patients with anal cancer. Based on previous data, a risk adaptive treatment approached is proposed in 4 groups: Low risk, standard risk, intermediate risk, and high risk. Human papillomavirus (HPV) DNA will be analyzed to identify novel biomarkers that predict chemoradiotherapy (CRT) response and toxicity.