摘要
Objective To determine the effect of postoperative radiotherapy on stage Ⅰ thymoma.Methods Twenty nine patients with stage I thymoma younger than 65 years, treated between August 1981 and January 1996 were included in this study. All patients were randomly assigned into two groups: surgery alone (13 patients) and surgery with postoperative radiotherapy (16). Staging was based on the surgical and pathologic criteria that the tumor had a complete capsule and without capsular invasion microscopically. Adjuvant radiotherapy was started within 4 weeks after surgery. Megavolage radiation, using the isocentric technique, was administered through an anterior field and/or two anterior oblique wedge fields. For the patients with lymphocytic predominant type, the dose was 50 Gy in 25 daily fractions for 5 weeks; for the patients with epithelial cell type or mixed type, the dose was 60 Gy in 30 daily fractions for 6 weeks. The survival rates were estimated by the Kaplan Meier method.Results There was no recurrence and metastasis in either group. No acute and late radiological injuries were found among the patients receiving radiotherapy postoperatively. The 5 year and 10 year survivals were both 92% for the patients treated by surgery alone. However, the survival rates for patients who received radiotherapy were both 88%. There was no difference in the survivals in these two groups. Of the 3 died patients, 1 died of myasthenia gravis and 2 of intercurrent illness. No significant correlation was found between myasthenia gravis and radiotherapy.Conclusions Postoperative radiotherapy is unnecessary for the patients with stage Ⅰ thymoma. No relation is found between radiotherapy and myasthenia gravis.
Objective To determine the effect of postoperative radiotherapy on stage Ⅰ thymoma.Methods Twenty nine patients with stage I thymoma younger than 65 years, treated between August 1981 and January 1996 were included in this study. All patients were randomly assigned into two groups: surgery alone (13 patients) and surgery with postoperative radiotherapy (16). Staging was based on the surgical and pathologic criteria that the tumor had a complete capsule and without capsular invasion microscopically. Adjuvant radiotherapy was started within 4 weeks after surgery. Megavolage radiation, using the isocentric technique, was administered through an anterior field and/or two anterior oblique wedge fields. For the patients with lymphocytic predominant type, the dose was 50 Gy in 25 daily fractions for 5 weeks; for the patients with epithelial cell type or mixed type, the dose was 60 Gy in 30 daily fractions for 6 weeks. The survival rates were estimated by the Kaplan Meier method.Results There was no recurrence and metastasis in either group. No acute and late radiological injuries were found among the patients receiving radiotherapy postoperatively. The 5 year and 10 year survivals were both 92% for the patients treated by surgery alone. However, the survival rates for patients who received radiotherapy were both 88%. There was no difference in the survivals in these two groups. Of the 3 died patients, 1 died of myasthenia gravis and 2 of intercurrent illness. No significant correlation was found between myasthenia gravis and radiotherapy.Conclusions Postoperative radiotherapy is unnecessary for the patients with stage Ⅰ thymoma. No relation is found between radiotherapy and myasthenia gravis.
