Standard Systemic Therapy Combined With High/Low-dose Radiotherapy Plus Toripalimab for Metastatic Colorectal Cancer

"First-line standard systemic therapies in cohort A include: FOLFOX/XELOX+ bevacizumab, FOLFOX/XELOX+cetuximab (KRAS/NRAS/BRAF WT and left-sided tumors only), FOLFIRINOX+ bevacizumab.~Second-line standard systemic therapies in cohort B include: FOLFOX/XELOX+ bevacizumab, FOLFOX/XELOX+cetuximab (KRAS/NRAS/BRAF WT), FOLFIRI/irinotecan+raltitrexed/irinotecan/+bevacizumab, FOLFIRI/irinotecan+raltitrexed/irinotecan/+cetuximab (KRAS/NRAS/BRAF WT), based on the previous first-line chemotherapy and adverse events.~Toripalimab will be given at 240 mg q3w. Radiotherapy regimes include 4-8 fractions of 4-12Gy via SABR or hypofractionated radiotherapy (HFRT) and 5 fractions of 0.5-2Gy via LDRT"