Organ Preservation Following Enverolimab-based Total Neoadjuvant Therapy for Locally Advanced Very Low Rectal Cancer

After reaching a cumulative radiotherapy dose of 25Gy in the entire pelvic cavity (PTV1), the treatment field was subsequently narrowed to solely focus on the primary tumor (PTV2), with a total dose of 35Gy administered. All patients will undergo fractionated radiotherapy, following a regimen of 7Gy per fraction, delivered every 3 weeks for five cycles.

Drug: Oxaliplatin,130mg/m2，ivgtt，d1,for 6 cycles. Drug: Capecitabine,1000mg/m2，po，bid，d1-14, for 6 cycles.

Envafolimab is administered by subcutaneous injection. The recommended dose is 300 mg per 3 weeks (Q3W) for 6 cycles.

Local full-thickness resection is employed for patients with clinical complete response (cCR) or near-clinical complete response (ncCR) following TNT.