RecruitingPhase 2Drug trialLarge Fraction Radiation Therapy Combined With Lenalidomide, and Glofitamab in Refractory Relapsed DLBCLTo prospectively evaluate the efficacy and safety of large fraction radiation therapy combined with granulocyte-macrophage colony-stimulating factor, lenalidomide, and glofitamab monoclonal antibody in the treatment of refractory relapsed diffuse large B-cell lymphoma patients