[Radiotherapy of invasive thymoma--an experience of Veterans General Hospital-Taipei (1980-1987)].

Forty four patients with the diagnosis of invasive thymoma were reviewed. The male to female ratio was 1.44:1, and the median age was 42. Thirty nine percent of the patients were associated with myasthenia gravis. Surgical management involved a complete resection in 28 cases and thoracotomy with biopsy or partial resection in 13 cases. All patients received radiotherapy. The 5-year actuarial survival was 57%. Myasthenia gravis did not adversely affect the survival. The patients who underwent complete resection had better survival than those who had residual tumor before radiotherapy (5-year actuarial survival 75% vs 33%). Five cases developed recurrence outside the radiation treatment field. In order to avoid marginal recurrence after radiotherapy, we recommended low dose irradiation (1500-2000 cGy) to the involved hemithorax, followed by a boost to the primary site up to a total dose of 5000 cGy. For the patients who had gross disseminated disease in the pleural cavity, combination of chemotherapy and radiotherapy should be considered.