Sequential Low-Dose Rate Half-Body Irradiation and Chemotherapy for the Treatment of Canine Multicentric Lymphoma

Abstract

Abstract Background Sequential half-body irradiation (HBI) combined with chemotherapy is feasible in treating canine lymphoma, but prolonged interradiation intervals may affect efficacy. A 2-week interradiation interval is possible in most dogs receiving low-dose rate irradiation (LDRI) protocols at 6 Gy dose levels. Hypothesis LDRI incorporated into a cyclophosphamide, doxorubicin, vincritine, and prednisone (CHOP)-based chemotherapy protocol is effective for the treatment of lymphoma in dogs. Animals Thirty-eight client-owned animals diagnosed with multicentric lymphoma. Methods Retrospective study evaluating the efficacy and prognostic factors for the treatment of canine lymphoma with sequential HBI and chemotherapy. Results The median 1st remission was 410 days (95% confidence interval [CI] 241–803 days). The 1-, 2-, and 3-year 1st remission rates were 54, 42, and 31%. The median overall survival was 684 days (95% CI 334–1,223 days). The 1-, 2-, and 3-year survival rates were 66, 47, and 44%. Conclusions and Clinical Relevance Results of this study suggest that treatment intensification by a 2-week interradiation treatment interval coupled with interradiation chemotherapy is an effective treatment for dogs with lymphoma.