Standard Dose Versus High Dose of Radiotherapy in Rectal Preservation With Chemo-radiotherapy in Rectal Cancer Patients

This study is testing whether a higher dose of radiation combined with chemotherapy can allow some rectal cancer patients to avoid surgery entirely — preserving the rectum. It compares a standard radiation dose to a higher dose, both given alongside chemotherapy (capecitabine). **You may be eligible if...** - You are 18 or older - You have rectal cancer (adenocarcinoma) confirmed by biopsy - The tumor is in the lower part of the rectum and measures no more than 4.5 cm across on MRI - Surgery has been recommended as a treatment option by a multidisciplinary team - Your blood counts, liver, and kidney function are adequate - You are not pregnant **You may NOT be eligible if...** - You have already had surgery or local treatment for this cancer - The cancer has spread to other parts of the body - You have had pelvic radiation before - You have had another cancer in the past 5 years (except non-melanoma skin cancer) - You are pregnant or breastfeeding - You already have a colostomy or ileostomy Talk to your doctor to see if this trial is right for you.