Ultra-fractionated Radiotherapy for Rectal Cancer

This study is testing an ultra-fractionated radiation approach for rectal cancer — meaning the radiation is given in many small doses spread over a longer period of time, rather than in fewer larger doses. Researchers want to see if this approach is safer and equally effective at treating locally advanced rectal cancer. **You may be eligible if you:** - Are 18 years of age or older - Have been diagnosed with rectal adenocarcinoma (rectal cancer) - Have locally advanced disease (T3–T4 and/or lymph node involvement) - Have not received any prior treatment for rectal cancer - Are in adequate health (ECOG performance status 0–2) - Have acceptable blood counts and organ function **You may NOT be eligible if you:** - Have received prior treatment for rectal cancer - Have very poor organ or bone marrow function - Are not able to tolerate the proposed treatment plan Talk to your doctor to see if this trial is right for you.