In this study, we used TomoTherapy® for treatment, which has potential advantages for rectal cancer patients, such as confirmation of the exact shape and location of a colorectal tumor, and decreased treatment-related side effects by minimizing damage to nearby healthy tissue. De Ridder et al. 27 first reported the efficacy of helical TomoTherapy® (23 fractions of 2 Gy within 5 weeks) on rectal cancer, with which only one patient developed grade 3, and this modality might decrease gastrointestinal toxicity.