Concurrent irradiation and intratumoral chemotherapy with cisplatin for treatment of a fibrosarcoma in a blue and gold macaw (Ara ararauna)

A myxoid fibrosarcoma in the wing of a blue and gold macaw (Ara ararauna) was treated with radiation therapy and intratumoral chemotherapy with cisplatin. The tumor was treated with a radiation dose of 40 Gy delivered during 22 days on an alternate-day schedule of 4 Gy/fraction and 3 chemotherapy treatments given once weekly at a dose of 0.3 mg of cisplatin per cm³ of tissue. Treatment was effective, and adverse effects were not noted clinically. Complete tumor remission was observed within 2 months after treatment completion, and the remission lasted 15 months until the macaw died of an unrelated cause. A cumulative effect of repeated intratumoral administrations on plasma concentrations of cisplatin was not observed during the course of treatment, although only trough levels were measured. Cisplatin-related systemic toxicities monitored by complete blood count and serum biochemical analysis were not found. Acute local reactions including edema and necrosis of the skin were self-limiting. Treatment complications included a decreased range of motion of the involved carpus. This may have resulted from radiation-induced fibrosis and bony fusion associated with bone remodeling. Results provide preliminary evidence that concurrent irradiation and intralesional chemotherapy may be an effective treatment for unresectable tumors in birds.