RecruitingDrug trialCadonilimab Combined With Fruquintinib and SBRT as Athird-line and Posterior Line Treatment in Patients With MSS CRCAn assessment of 6-month progression-free survival in patients with mCRC with third-line and postline metastatic colorectal cancer in combination with cardonilizumab and fuquinitinib and SBRT compared with fuquinitinib monotherapy