改进鼻咽癌外照射技术的前瞻性临床研究

A clinical trial in improving external irradiation technique for nasopharyngeal carcinoma

目的：前瞻性地观察改进鼻咽癌外照射技术对临床治疗疗效的影响。方法：从1992年3月至1995年6月，124例初治鼻咽癌病人按T、N、M分层配对分为改进方案治疗组(先面颈联合野照射40～45Gy，后用面颈分野照射至根治量或预防量，采用低熔点挡块技术)或常规方案治疗组(全程放疗均采用面颈分野)进行治疗，然后比较两组的近远期疗效及其正常组织的早发和晚发放射反应。结果：放疗后2～3月的CT检查显示改进方案治疗组原发灶完全消退率(58.06％)高于常规方案治疗组(30.64％)(P<0.05)，而改进方案治疗组口腔粘膜和胃肠早发放射反应轻于常规方案治疗组(P<0.05)。远期随访显示改进方案治疗组1、3和5年总的生存率、无瘤生存率和无局部区域复发率均高于常规方案治疗组(P<0.05)，且改进方案治疗组的后组颅神经放射损伤率(4.8％)低于常规方案治疗组(16.1％)(P<0.05)。结论：与常规方案相比，改进方案提高了鼻咽癌的局部区域控制率，提高了病人的生存率和生存质量，值得推广应用。

Objective： To improve the external irradiation technique for nasopharyngeal carcinoma. Methods： From Mar.1992 to Jun.1995, 124 patients with pathologically confirmed nasopharyngeal carcinoma(stageⅡ ～ Ⅳ a) and without any kind of anti tumor treatment previously, were randomly assigned into the investigation group(initially using two lateral faciocervial photon fields to 40～ 45 Gy/20～ 22 fractions in 4～ 4.5 weeks, followed by two lateral facial photon fields or plus a anterior facial field to 26～ 30 Gy/13～ 15 fractions in 2～ 3 weeks, utilizing cerrobend block) and conventional group (using two or three facial fields and anterior posterior and opposal lateral cervical fields to same dose). The short and long term clinical outcome, acute and late radiation sequelae were observed. Results： After 2～ 3 months following radiation therapy, CT scans revealed that complete remission rate (58.06％ ) of primary lesion in investigation group was higher than that(30.64％ ) in conventional group(P=0.002),and the acute radiation reaction of oral cavity and GI in investigation group was milder than that in conventional group(P< 0.05). The 1 ,3 and 5 year overall survival rates in investigation group and conventional group were 96.88％ , 77.59％ , 70.84％ and 87.50％ ,59.43％ ,55.47％ , respectively (P=0.025). The 1 , 3 and 5 year disease free survival rates in investigation group and conventional group were 83.87％ ,67.10％ ,60.03％ and 74.19％ ,50.69％ ,46.47％ , respectively (P=0.045). The 1 ,3 and 5 year localregional failure free rates in investigation group and conventional group were 90.32％ ,79.45％ ,71.08％ and 83.06％ , 61.14％ , 56.05％ respectively (P=0.037). While the 1 ,3 and 5 year free distant metastasis in investigation group and conventional group were 87.10％ , 73.55％ , 73.55％ and 87.10％ , 74.63％ , 74.63％ respectively (P=0.988). The radiation injury rates of IX, X, XI and/or XII cranial nerves were lower in investigation group (4.8％ ) than that in conventional group (16.1％ ) (P=0.04). Conclusions： Compared with conventional irradiation technique, the improving external irradiation technique may elevate localregional control rate, the survival rate and life quality of patients with nasopharyngeal carcinoma.