20年来鼻咽癌放射治疗疗效全面提高的原因分析

目的探讨２０年来鼻咽癌（ＮＰＣ）放射治疗技术的变革和其疗效变化的关系。方法选职在确定靶区和野界定位及放射治疗技术上各有代表性的１９７１年组１４２例。１９７６年组２０１例和１９９１年组２３２例全部初治的ＮＰＣ病人，对比其长期疗效和后遗症情况。１９９１年组全部用ＣＴ确定靶区和野界定位。７０年代２个组皆用面颈分野技术，并以耳前野为主野，１９７６年组加用全颈前切线野；１９９１年组改以面颈联合野为主野，并停用或减少上颈前切线野的剂量，颈淋巴结的剂量以电子束补足。１９９１年组的原发灶和颈淋巴结剂量分别提高约１５％和１７％。结果１９９１年组的各项长期疗效指标均明显优于７０年代的２个组，而后遗症发生率未上升。１９９１年组的寿命表达５年总生存率、无癌生存率、局部控制率和无远地转移率分别为７４．５％，５６．１％，８７．９％和８２．６％。结论应用ＣＴ及面颈联合野和合理提高剂量可改善ＮＰＣ放射治疗疗效。

Reasons of improvment the radiotherapy results for nasopharyngeal carcinoma during the past 20 years

Objective To evaluate the improvenment of radiotherapeutic techniques between 1971 to 1991 and their influence on the outcome of radiotherapy for nasopharyngeal carcinoma(NPC). Methods A total of 575 cases of NPC, including 142 cases in 1971, 201 cases in 1976 and 232 cases in 1991 who received radiotherapy in our hospital were analyzed to compare the long term treatment results of each of these groups. Determination of target volume and delineation of Portal boundaries were dased on CT scan in all patients in the 1991 group. Radiation technique: In the two 1970s groups, Primary tumor and cervical lymphadenopethy were irradiated separately, with the pre-auricular portal as the main portal. In the 1976 group, A whole neck anterior tangential portal was sddded for cervical lymphadenopathy, In 1991,the joint facio-cervical portal began to be used as the main portal in almost all(97%) patients and the dose of the upper neck anterior tangential portal was reduced or no longer used altogether. Instead, electronic beam was adopted for boosting in the posterior cervical area. Radiation dose for the primary tumor and cervical lymphadenopathy in the 1991 group was increased by 15% and 17% than the two 1970s groups. Results The long term results in the 1991 group were better than the two 1970s groups without raising the morbidity of radiation complication. For the 1991 group, life-table's five year overall survival rate was 74.5%;diseasefree survival rate 56.1%;local control rate 87.9%;distant-metastasis-free survival rate 82.6%. Conclusions Application of CT scan, adoption of joint facio-cervical portal, and reasonabe increase in radiation dose have bettered the radiotherapy results of NPC in the past 20 years.