Ⅲ期胸腺癌放疗范围的初步探讨

Optional field size of radiotherapy through analysis 35 patients with stage Ⅲ thymic carcinoma

目的初步探讨胸腺癌的放疗范围。方法35例Ⅲ期胸腺癌中，男22例，女13例，中位年龄53．7岁。鳞癌16例，分化差癌9例，不能分型10例。20例手术治疗，12例接受2个周期以上含铂类为主的化疗。34例接受放疗，按放疗范围分为局部照射组（瘤床或原发灶外放2 cm）和扩大照射组（全纵隔全心包加或不加锁骨上区），其中19例为局部照射，15例为扩大照射。除扩大照射组累及重要血管稍多外，两组其他临床特征相似。结果全组中位生存时间44个月，5、10年总生存率分别为45%、35%。接受完整切除和不完整切除及未手术的5、10年生存率分别为100%、100%和56%、39%及11%、11%（P=0．028）。只侵犯了周围组织的10年生存率为53%，而重要血管受侵者无5年生存（P=0．000）。接受局部照射和扩大照射者疗效相似，5、10年生存率分别为49%、34%和34%、34%（P=0．647）。局部照射组有3例放射性心包炎，而扩大照射组除2例放射性心包炎外，还有3例放射性肺炎。局部照射组和扩大照射组治疗失败分别为10、3例，但8例失败部位不在扩大照射的范围内。再程治疗的中位生存时间为14．2个月。结论手术性质和肿瘤侵犯范围是影响Ⅲ期胸腺癌生存的重要因素。给予全纵隔全心包的扩大放疗，预后无明显改善。对转移复发者应给予积极的再程治疗。

Objective Through analysis of 35 patients with stage Ⅲ thymic carcinoma to study the optional field size of radiotherapy. Methods From Sept. 1963 to July 2003, thirty-five patients with Masaoka＇s stage Ⅲ thymic carcinoma were analyzed retrospectively, with 22 males and 13 females, median age 53.7 yeas. Twenty patients were treated by surgery, and 12 patients were given chemotherapy （median cycle of 4 cycles）. There were 34 patients given radiotherapy, with a median dose of 60 Gy. According to the field size, 19 patients were treated with local field（including the tumor with 2 cm margin）, 15 patients with extended field（including the whole mediastinum and pericardium, with or without the supraclavicular area）. Results The overall survival rate of 5- and 10-year was 45% and 35%, respectively, with median survival time of 44 months. The 5- and 10-year survival rate in patients with total, partial resection, and without resection was 100% and 100%, 56% and 39%, 11% and 11%, respectively（P =0.028）. The 10-year overall survival rate was 53% in patients without invasion of the neighboring tissues. It was zero with invasion of the great vessels. The 5- and 10-year survival rate in patients with local radiation fields and extended fields was 49% ,34% and 34%, 34% （P = 0. 647 ）, with median time of 42 months and 44 months, respectively. The difference between the two radiotherapy groups was in significant （ P = 0.645 ）. Three patients developed radiation pneumonitis in the local radiation. Three patients had irradiation pericarditis in the local field group, 2 patients had irradiation pericarditis and 3 patients radiation pneumonitis in the extended field group. Conclusions The most important prognostic factors of staging Ⅲ thymic carcinoma was whether it is resectable and the invasion of great vessels. Extended irradiation with the whole pericardium, the whole mediastinum, with or without the supraclavicular area may improve the local control, but not the overall survival. The salvage treatment of patients who failured should energetically be carried out.