Radiotherapy Combined QL1706, TAS-102 and Bevacizumab in mCRC

Inclusion Criteria: * Aged 18 to 75 years . * Histologically confirmed unresectable colorectal adenocarcinoma. * Patients must have received at least one prior line of oxaliplatin-, irinotecan-, or 5-FU-based therapy with documented progression or intolerance. * Documented KRAS and BRAF mutation status (mutant or wild-type) must be available. * Palliative radiotherapy targeting primary or metastatic lesions is planned. * At least one measurable lesion per RECIST v1.1 exists. * ECOG score of 0-1 and life expectancy ≥12 weeks. * Adequate bone marrow, hepatic, and renal function must be demonstrated. * Fertile patients commit to using effective contraception during and for 6 months post-treatment. Exclusion Criteria: * History of Grade ≥3 immune-related adverse events (irAEs) from prior immunotherapy deemed contraindications for retreatment. * Radiation or systemic anticancer therapy within 14 days prior to first study treatment. * Active CNS metastases and/or leptomeningeal disease (LMD). Symptomatic interstitial lung disease (ILD), active pneumonitis, uncontrolled infections, or non-healing wounds/fistulae. * Intestinal perforation risks: active diverticulitis, intra-abdominal abscess, GI obstruction, or cancer-related peritoneal carcinomatosis. * Uncontrolled or symptomatic serous cavity effusions (pleural, ascites, pericardial). * Uncontrolled cardiovascular/cerebrovascular diseases. * Medical/social conditions that may compromise study results or lead to premature termination per investigator judgment.