摘要目的：观察胸部肿瘤放射治疗期间应用N-乙酰半胱氨酸（NAC）对放射性肺损伤的保护作用。方法86例胸部肿瘤患者接受常规放射放疗，随机分成两组，设放疗＋N-乙酰半胱氨酸组（RT＋N）和单纯放疗组（ RT），两组通过胸部CT进行放疗后观察，严重程度按RTOG放射性肺炎分级标准进行观察，放疗前和放疗4周后每2周观测血浆转化生长因子（TGF-β1），白介素1（IL-1）、白介素4（IL-4）、肿瘤坏死因子（TNF）指标，在放疗8周结束后终止观察。结果86例患者放疗3个月，RT＋N组放射性肺炎≥2级者占23．3％而RT组≥2级者占53．5％。 RT＋N组放射性肺炎发生率低于RT组，两组差异有统计学意义（P＜0．01）；6、9、12个月时，肺纤维化的发生率（RT＋N）组为28．4％、25．4％、22．4％；RT组分别为58．4％、54.4％、52．4％，两组比较差异有统计学意义（ P＜0．05）。 TGF-β1、IL-1、IL-4、TNF水平，在放疗期间及8周后，RT组明显高于RT＋N组。结论 N-乙酰半胱氨酸在胸部肿瘤患者放射治疗时能够减少急慢性放射性肺损伤的发生率，同时也能降低TGF-β1、IL-1、IL-4、TNF的含量与表达。

abstractsObjective To observe the protective effect of N-NAC on radiation-induced lung injury. Methods 86 cases of thoracic neoplasm patients were chosen and randomly divided into two groups,group RT +N(n =43)and group RT(n =43).Two groups were observed by CT after radiotherapy.Acute and chronical toxicities were graded by RTOG.TGF-β1,IL-1,IL-4,TNF were observed before and after the radiotherapy.Results After 3 monthsof radiotherapy,RTOG≥2 was 23.4%(RT +N),while RTOG≥2 was 53.1%(RT).there was significant differencebetween the two groups(P <0.01).At 6,9 and 12 months,fibrosis was present in 28.4%,25.4%,22.4% receivingRT vs 58.4%,54.4%,52.4% receiving RT +N,there was significant difference between the two groups(P <0.05).TGF-β1,IL-1,IL-4,TNF were observed which showed that The RT +N were lower than RT.Conclusion N-NAC can reduce incidence rate of lung injury in radiotherapy,and can reduce the content and the release of TGF-β1,IL-1,IL-4,TNF.