Radiation therapy for advanced canine nasal planum squamous cell carcinoma: case report

ABSTRACT This case report describes the outcome of treatment of dogs with advanced (deeply invasive) nasal planum squamous cell carcinomas with palliative or definitive radiation therapy. All dogs were diagnosed with nasal planum squamous cell carcinoma by histopathology, and their owners declined aggressive surgery. Dogs were treated with a cobalt-60 unit, definitive-intent radiation protocol consisting of 15 daily fractions (Monday-Friday) of 2.8 Gy, and palliative radiation protocol consisting of 4 fractions of 8 Gy performed once a week. Three dogs had T3 tumors and three had T4 tumors according to the WHO staging system. Two dogs had tumor complete remission and four had tumor partial remission. Survival time of dogs submitted to radiation therapy was 95-417 days. Radiation acute side effects involved only mild epilation and cutaneous erythema in palliative protocols, and moist desquamation, epilation, mild rhinitis and oral mucositis in definitive-intent RT. Radiation therapy, especially palliative protocols, can be a treatment option for nasal planum squamous cell carcinoma in dogs, when the owner declines aggressive surgery. It may contribute to partial or complete tumor remission and better patient quality of life, even at advanced stages, leading to mild side effects.