Clinical Presentation of Frontal Sinus Squamous Cell Carcinoma in the Dog and Response to Treatment With Radiation Therapy in Eight Dogs

ABSTRACT

Primary frontal sinus squamous cell carcinoma (PFSSCC) represents a rare disease in dogs, and there is a general paucity of information in the current veterinary literature regarding its presentation and response to radiation therapy.

The objective of this retrospective observational study was to describe a series of dogs diagnosed with PFSSCC and report their response to radiation therapy.

Medical records of dogs with a diagnosis of PFSSCC were reviewed. Data collected included signalment, presenting complaint, clinicopathologic and diagnostic imaging findings, treatment, therapeutic response, and date of death or last follow‐up.

Eight cases of PFSSCC in dogs were treated with radiation therapy at the authors' institution. Three of these dogs were treated with coarse‐fractionated radiation therapy. One dog was euthanized due to an unrelated cause 36 months after completing the radiation therapy. The second and third dogs survived 18 and 3 months, respectively, from the end of treatment to death due to PFSCC. Five further dogs were treated with a more fractionated protocol (Monday–Wednesday–Friday schedule). The median survival time for all patients was 7.5 months (range 2–36 months).

Despite the small number of cases and variation in the radiation protocols used, the treatment outcomes in these eight dogs suggest that radiation therapy is potentially a viable treatment option for dogs with PFSSCC and that coarse fractionation might be an appropriate approach if more finely fractionated protocols are not possible.