不同放射治疗方式致鼻咽癌患者腮腺功能损伤的研究

目的评价不同放射治疗方式对鼻咽癌患者腮腺功能的损伤状况。方法常规分割（CF）组175例,总量70Gy;后程加速超分割放射治疗（LCAF）组63例,先用CF照射36—40Gy,再用LCAF照射35～40Gy,总量75Gy;调强适形放射治疗（IMRT）组142例,处方剂量72Gy。放射治疗期间观察急性放射性腮腺炎发生情况,2年后测定腮腺静止性分泌功能。结果IMRT组的腮腺受照射剂量远远低于其他两组。CF组、LCAF组和IMRT组急性放射性腮腺炎发生率分别为23．4％、41．3％和20．4％,差异有统计学意义（P〈0．05）。2年后,CF组、LCAF组和IMRT组腮腺分泌功能下降率分别为81．7％、81．0％和69．7％,差异有统计学意义（P〈0．05）。结论不同放射治疗方式对鼻咽癌患者的腮腺功能损伤程度不同,IMRT有利于覆盖肿瘤靶区,并使邻近敏感器官获得有效分割,使腮腺功能得到较好保护。

Parotid dysfunction after various methods of radiotherapy for nasopharyngeal carcinoma

OBJECTIVE: To evaluate the radiation induced parotid dysfunction in nasopharyngeal carcinoma (NPC) patients who had received different methods of radiotherapy. METHODS: From January 1996 to January 2000, 380 NPC patients were divided into conventional fraction (CF-175 patients), late-course accelerated hyperfractionation (LCAF-63 patients) and intensity modulated radiation therapy (IMRT-142 patients) groups. Conventional radiotherapy was given with a total dose of 70 Gy. Patients in the LCAF group were treated with the same fractionation as CF group until the dose of 36 - 40 Gy, then followed by LCAF radiotherapy to a total dose of 75 Gy. IMRT in the form of full-course was given to a total dose of 72 Gy. Acute parotiditis was observed during the treatment. The parotid secretory function was examined 2 years after radiotherapy. RESULTS: The dose of parotid in IMRT was much lower than those in the other 2 groups. Extreme damage rates of parotid secretory function in CF, LCAF and IMRT groups were 81.7%, 81.0% and 69.7% (P < 0.05); acute parotiditis rates were 23.4%, 20.4% and 41.3% respectively, with the differences among the 3 groups significant (P < 0.05). CONCLUSION: The radiation parotid functional damage differs in the various methods of radiotherapy. IMRT, being able to improve the tumor target coverage and spare the adjacent critical structures, is indicated for NPC.