Large Fraction Radiation Therapy Combined With Lenalidomide, and Glofitamab in Refractory Relapsed DLBCL

This study is testing a combination of high-dose targeted radiation (given in fewer, larger doses), plus two cancer drugs — lenalidomide (an immune-boosting pill) and glofitamab (a type of immunotherapy) — for people with a type of aggressive blood cancer called diffuse large B-cell lymphoma (DLBCL) that has come back or stopped responding to treatment. **You may be eligible if...** - You are 18 or older with a confirmed diagnosis of DLBCL - Your cancer has relapsed or did not respond to at least one prior treatment - You have not previously received a type of drug called a bispecific antibody - You are reasonably active and expected to live more than 3 months - Your heart, liver, and kidney function are within acceptable ranges **You may NOT be eligible if...** - You have previously received bispecific antibody therapy - Your cancer has spread to the brain in a way that cannot be treated - Your overall health or organ function is too poor to tolerate treatment - You have certain other serious medical conditions Talk to your doctor to see if this trial is right for you.