Phase II evaluation of high dose accelerated radiotherapy for anaplastic thyroid carcinoma

Anaplastic thyroid cancer responds poorly to conventional radiotherapy and prognosis in the absence of effective chemotherapy is dismal. The median survival following diagnosis is only 4 months and the majority of patients die with uncontrolled local disease. This study describes the use of accelerated radiotherapy aiming to improve local response in patients with anaplastic thyroid carcinoma. Toxicity was assessed prospectively.

Seventeen patients with anaplastic thyroid carcinoma were treated and assessed for both outcome and treatment toxicity. Eight further patients with primary carcinomas arising in the neck were also treated with this protocol but were assessed for treatment toxicity only. Patients were treated twice daily, 5 days a week, to a total dose of 60.8 Gy in 32 fractions over 20-24 days in two or three phases.

Three patients with anaplastic carcinoma demonstrated a complete clinical response and seven patients achieved a partial response. Five patients had stable disease and two patients died before radiotherapy was completed. Toxicity from oesophagitis and dysphagia was high with 10 patients requiring intravenous fluids or nasogastric tube feeding.

This approach improved the response rate to radiotherapy but toxicity was unacceptable. A modified accelerated radiotherapy protocol is being explored.