Three-dimensional conformal radiation therapy for inoperable massive hepatocellular carcinoma in six dogs.

Abstract

OBJECTIVES: To evaluate the activity and tolerability of three-dimensional conformal radiation therapy (3D-CRT) in dogs with massive hepatocellular carcinoma. MATERIALS AND METHODS: Six dogs with massive hepatocellular carcinoma that were ineligible for surgical resection or with owners who declined surgical resection, and underwent 3D-CRT were retrospectively reviewed. 6 to 10 Gy per fraction was prescribed at isocentre of planning target volume to a total dose of 18 to 42 Gy with 1 to 2 fractions per week for a total of 3 to 7 fractions. Follow-up examinations included physical examination, contrast-enhanced CT scan and blood analysis (complete blood count, electrolytes and serum biochemical panel). RESULTS: The median follow-up time after 3D-CRT was 534 (range, 281 to 1057) days. An objective response was observed in five of six cases. Radiation-induced liver disease developed in one dog but was asymptomatic and reversible. Toxicity was not noted in any other dog. CLINICAL SIGNIFICANCE: 3D-CRT appears to be a viable treatment option for dogs with inoperable massive hepatocellular carcinoma.