Survival outcomes of dogs with multicentric lymphoma treated with sequential half-body radiotherapy and L-CHOP without maintenance chemotherapy.

Adding LDR half-body radiotherapy to L-CHOP nearly doubles progression-free and overall survival in dogs with multicentric lymphoma.

This retrospective case-control study evaluated whether combining L-CHOP chemotherapy with low-dose-rate sequential half-body radiotherapy (LDR-HBRT, 6 Gy at 8–14 cGy/min) improves outcomes in dogs with intermediate- to high-grade multicentric lymphoma compared to a standard 6-month L-CHOP protocol alone without maintenance chemotherapy. Seventy-five dogs in the L-CHOP-LDR-HBRT group were compared to 115 controls. The combination protocol produced significantly longer median progression-free survival (PFS: 532 days vs. 296 days) and overall survival (OS: 752 days vs. 457 days), both statistically significant (P < .0001). A notable finding was that delays in delivering caudal half-body irradiation negatively impacted both PFS and OS, underscoring the importance of treatment timing. Adverse event data, available for 30 of the HBRT-treated dogs, revealed that most toxicities were low-grade. Grade 3–4 toxicities occurred in only 4.5% of all administered treatments, and only one dog required hospitalization following HBRT. Dose reductions and treatment delays occurred in 39 and 74 instances, respectively, across the 28-week protocol. The authors conclude that incorporating LDR-HBRT into L-CHOP protocols—without adding maintenance chemotherapy—may substantially extend remission and survival in dogs with multicentric lymphoma, while maintaining a predominantly mild and manageable toxicity profile. These findings support further prospective investigation of HBRT as a component of canine lymphoma treatment.

This summary was distilled by AI and may occasionally misinterpret data. Confirm critical details with the primary literature before clinical application.