Online Adaptive Radiation Therapy for Rectal Cancer

A Prospective Study to Evaluate Online Adaptive Radiotherapy in Rectal Cancer

In the present study, the investigators will evaluate the efficacy, toxicities, and of online adaptive radiation therapy (ART) for patients with rectal cancer treated with neoadjuvant chemoradiotherapy.

Inclusion Criteria:

1. ≥18 years old;
2. Diagnose with rectal cancer;
3. T3-T4 or N+, and no distant metastasis
4. Neoadjuvant chemoradiotherapy intended;
5. Surgery is expected after neoadjuvant therapy;
6. ECOG score 0-2, expected to lie in the treatment bed for at least half an hour;

Exclusion Criteria:

1. With contraindications to rectal MRI;
2. Received surgery, radiotherapy or chemotherapy for rectal cancer;
3. History of pelvic radiotherapy.