[Treatment of invasive thymoma using low dose and extended-field irradiation including hemi-thorax or whole-thorax]

The records of 10 patients treated for invasive thymoma with low-dose and extended-field irradiation including hemi-thorax or whole-thorax are reviewed. Six patients were in stage III. They were treated with up to 15 Gy hemi-thorax irradiation which was followed by shrinkage of the radiation field after removal of tumor. Five of them have lived 4 to 10 years, while one remaining patient died of uncertain cause. Four patients had stage IVa thymoma. Two patients in an earlier stage were treated with irradiation alone; whole-thorax irradiation of up to 20 Gy followed by local irradiation. Those two patients, however, developed severe pulmonary infection secondary to irradiation pneumonitis. Furthermore, local relapse was observed in one patient who died of respiratory insufficiency after 6 years. In the remaining 2 patients in stage IVa, intensive chemotherapy was administered before whole-thorax irradiation of up to 15 Gy. One of these patients is alive with no evidence of recurrence for 5 years, while the other died of a disease not related to thymoma. These facts indicate that whole-thorax irradiation combined with chemotherapy may be of value in preventing local relapse with stage IVa thymoma.