Radiation therapy for oral melanoma in dogs: A retrospective study

ABSTRACT: Our retrospective study evaluated the survival of 24 dogs with unresectable malignant melanoma treated with radiation therapy. Fifteen dogs were treated with radiation therapy (RT) and chemotherapy (CT), five with surgery followed by RT and CT, three with palliative RT, and one with electrochemotherapy associated with RT. All dogs were treated with an orthovoltage Stabilipan I. The protocol used was three or four weekly fractions of 8 Gy. Carboplatin was administered every 21 days, a total of four times. Five percent of dogs were classified as having stage I melanoma, 17% as stage II, 50% as stage III, and 17% as stage IV. Sixty-four percent had a partial response to treatment, 29% achieved complete remission, and 7% remained in a stable disease state. The mean survival time was 390 days for stage I, 286 days for stage II, 159 days for stage III, and 90 days for stage IV. We concluded that radiation therapy can be considered a viable alternative for the palliative treatment of canine oral melanoma.