Radiation therapy
for fibrosarcoma
in pets — Florida.

Surgery and radiation, working together.

Fibrosarcomas are defined by their infiltrative growth pattern — microscopic tumor extensions reach well beyond what the surgeon can see or feel. This is why even an apparently complete resection may leave microscopic disease, and why adjuvant radiation is often recommended. Radiation treats the microscopic disease that may remain after surgery.

In dogs, fibrosarcoma most frequently arises in the oral cavity — gingiva, hard palate, and maxilla — where the proximity to bone makes complete resection particularly challenging. Subcutaneous and extremity fibrosarcomas also occur. In cats, oral fibrosarcoma is less common than SCC, but injection-site fibrosarcoma (vaccine-associated sarcoma) is a well-recognized and highly aggressive entity treated with a specialized surgical + radiation approach.

Adjuvant vs. definitive radiation

Adjuvant radiation therapy — delivered after surgery — is the standard approach when resection is performed but margins are narrow or incomplete. This is the most common scenario for oral fibrosarcoma. Definitive radiation therapy is used as the primary treatment when surgery is not feasible due to tumor size, location, or the pet's overall health. Both achieve meaningful local control.

CT is essential before any treatment decision

CT imaging defines the true extent of fibrosarcoma — bone involvement, vascular proximity, regional lymph node status, and the feasibility of surgical resection. This information directly shapes the radiation field and the treatment plan. Dr. DiBernardi reviews all imaging personally and coordinates with the surgical team when combined therapy is planned.