Radition Therpay Control of Nine Patients with Malignant Thymoma

Malignant thymoma is a relatively rare condition and a review of the literature reveals approximately 100 reported cases. Only a small percentage of these have been treated with megavoltage radiation therapy; therefore, it is difficult to find the necessary information to establish a proper time-dose relationship for treatment. This report deals with the radiation therapy and survival data concerning nine patients treated for malignant thymoma during a ten year period at the Medical University of South Carolina. Megavoltage irradiation in the dose range of 3500-4800 rads was employed in all patients. All gross tumor was completely resected in only three patients, two had a biopsy only, and the remaining four had subtotal resections. Local tumor control has been 100% with the average follow-up being 5.5 years and a minimum of 30 months. Three patients are dead; one from intercurrent disease, one from myasthenia gravis, and one from radiation injury to the spinal cord. One patient is alive with metastatic disease controlled by chemotherapy. The technique of radiation therapy is outlined, as well as suggested treatment policy.