Salvage Radiation Treatment for Primary Refractory Diffuse Large B-cell Lymphoma After Chimeric Antigen Receptor (CAR) T-cell Therapy: A Case Report.

BACKGROUND Treatment of refractory/relapsing diffuse large B cell (R/R DLBCL) lymphoma remains a challenge. Radiation therapy (RT) has versatile roles in R/R DLBCL treatment: it can be used in the peri-transplant setting for transplant-eligible candidates, or as a salvage or palliation therapy depending on the extent of the disease in transplant-ineligible patients. The introduction of chimeric antigen receptor (CAR) T-cell therapy has changed the landscape of R/R DLBCL. RT has been used as a bridging therapy to CAR T-cell therapy in order to control disease progression during its manufacturing period. However, optimal RT and CAR T-cell therapy integration is still unknown. Salvage strategies for R/R DLBCL post-CAR T-cell therapy have been little studied. CASE REPORT Here, we present a case of primary refractory DLBCL with residual disease post-CAR T-cell therapy successfully treated with salvage RT. CONCLUSION Radiotherapy could be an effective salvage strategy for R/R DLBCL post-CAR T-cell therapy. Exact mechanisms await exploring.