鼻咽癌立体定向适形放疗后张口困难的观测与分析

The observation and analysis of the radiation-reduced trimus in nasopharyngeal carcinoma patients treated with stereotactic radiotherapy

目的:分析立体定向适形放疗颞合关节和咀嚼肌群受照剂量与发生张口困难的关系。方法:61例鼻咽癌患者接受立体定向适形放疗,照射靶区为鼻咽肿瘤、鼻咽区、咽旁间隙和颈部淋巴区,靶区处于95%剂量曲线内,总剂量30-42Gy/10-14次.20-30天。颞合关节和咀嚼肌群处于50%-60%的剂量曲线内。放疗前及放疗后6个月、1年、2年和3年分别用直尺测量患者门齿距。结果:全组1年局控率95.08%(58/61),1、2、3年累积生存率为95.08%(58/61)、93.22%(57/61)、90.16%(55/61)。颞合关节和咀嚼肌群剂量15.79Gy-30.95Gy(19.21±4.56)。Ⅰ-Ⅱ级张口困难发生率4.91%(3/61),未观察到Ⅲ级和Ⅳ级张口困难。相关性检验表明颞合关节和咀嚼肌群剂量与张口困难之间无相关性。结论:立体定向适形放疗技术使颞合关节和咀嚼肌群受照剂量显著下降,放疗后张口困难发生率显著降低。

Objective： To analyze the relationship of radiation - reduced trimus and the stereotactic radiation （SRT） dose of temporomandibular joint and the masseter group in nasopharyngeal carcinoma （NPC）. Methods： Sixty one naive NPC patients were treated with SRT,and the target, which included area around the nasopharynx, space around the parapharyngeal and the area of neck lymph node,were surrounded by 95% isodose curve and by 30 - 42Gy/10 - 14f ＊ 20 - 30days. The temporomandibular joint and the masseter group were surrounded by 50% - 60% isodose curve ,and its radiation dose were 15.79Gy -30.95Gy（ 19.21±4.56）. The distance between 2 dens incisivus medialis （DDIM） was measured before radiotherapy and 6 months, 1 year, 2 years, and 3 years later respectively. Results： The overall 1 - , 2 - , and 3 - year survival rates were 96.56% ,93.33% and 92.06% respectively . The radiation dose to temporomandibular joint were 15.79Gy - 30.95Gy （ 19.21± 4.56 ）. Three （4.91%） patients suffered from grade Ⅰ - Ⅱ trimus after SRT,and no patient had grade Ⅲ - Ⅳ trimus. Conclusion： SRT can free the temporomandibular joint from high dose radiation. The risk of radiation - induced severe temporomandibular joint damage , and trimus in NPC patients after SRT is significantly low.