SIB-RT Combined With CAPOX and PD-1 for High-Risk Rectal Cancer

The biological effective dose of short-course radiotherapy is relatively lower compared to long-course radiotherapy, which may lead to an increased local recurrence rate in patients with mid to low rectal cancer who are at high risk of locally advanced disease due to insufficient radiation dose. Combining short-course radiotherapy with simultaneous integrated boost (SIB) and immunotherapy-chemo regimens could potentially further enhance tumor regression and improve local control, providing a promising treatment option for high-risk locally advanced rectal cancer patients. Therefore, this clinical trial aims to explore the safety and effectiveness of a short-course SIB radiotherapy regimen combined with immunotherapy and chemotherapy as neoadjuvant treatment for locally advanced rectal cancer, based on short-course radiotherapy combined with chemotherapy and immunotherapy.