食管癌后程加速超分割照射剂量学研究

A dose study of the late course accelerated hyperfractionation radiotherapy for esophageal carcinoma

目的探讨食管癌后程加速超分割照射剂量并观察两组的近期疗效、局部控制率、放疗耐受性及副反应,并随访其长期生存率。方法采用随机抽签法将100例食管癌随机均分为60 Gy组和75 Gy组。60 Gy组前3周采用常规分割照射,第4周起改用超分割照射(1.5 Gy/次,2次/d,2次间隔6 h,10次/周),DT60 Gy分35次,5周完成。75 Gy组照射方法完全相同,前3周常规分割,第4周起改用超分割照射,DT75 Gy,分45次,6周完成。结果两组近期疗效无差别,75 Gy组无C级。1、3、5年局部控制率60 Gy组分别为86%、42%3、2%,75 Gy组分别为88%、52%、48%;13、、5年生存率60 Gy组分别为86%、40%2、8%,75 Gy组分别为72%、34%、16%;两组比较均无差别。中位生存期60 Gy组25个月,75 Gy组19个月。75 Gy组重度放射性食管炎明显高于60 Gy组(28%∶10%,P=0.022),但75 Gy组与60 Gy组死亡原因无差别。结论食管癌后程加速超分割照射不宜追求高剂量,在照射野及照射技术不变的情况下增加剂量,副反应加大。在考虑增加照射剂量时应充分考虑肺及其他正常组织的受照体积及受照剂量。

Objective To discuss the optimal radiation dose in the treatment of the late course accelerated hyperfractionation （LCAH） radiotherapy for esophageal carcinoma by using two different treatment doses, focusing on the difference of the short term results, local control rates, treatment tolerance and long term survival rates between the two groups. Methods One hundred patients with esophageal carcinoma were randomly divided by the envelope method into two groups ： the 60 Gy group and the 75 Gy group. Patients in 60 Gy group received conventional fraction radiation for the first 3 weeks, and then hyperfractionation radiation （ 1.5 Gy per fraction, two fractions a day with 6 hour interval, 10 fractions per week） to the total dose of 60 Gy/35 fractions/5 weeks. The radiation schedule of the 75 Gy group was the same as the 60 Gy group： conventional fractionation of radiation for the first 3 weeks and then hyperfractionation radiation for the rest 3 weeks to the total dose of 75 Gy/45 fractions/6 weeks. Results There was no significant difference between the two groups in short term results. The 1-, 3-, 5-year local control rates were 86% ,42% ,32% in 60 Gy group and 88%, 52%, 48% in 75 Gy group, respectively. The 1-,3-,5-year survival rates were 86%, 40%, 28% in 60 Gy group and 72%, 34%, 16% in 75 Gy group ,with no significant difference （ P = 0.283）. The median survival time was 25 months for the 60 Gy group and 19 months for the 75 Gy group . Patients suffered from heavy radiation-induced esophagitis in the 75 Gy group were significantly more than those in the 60 Gy group （28% vs 10%, P = 0.022）. But it was similar for patients who died of side effects in the two groups. Conclusions It is not suitable to pursue high dose in treating esophageal carcinoma with late course accelerated hyperfractionation radiotherapy as high incidence of side effects are unadvoidable if the dose is increased without changing the radiation fields and techniques. When escalating the dose to the esophagus, the radiated lung volume as well as the other normal tissues should be first subjected to meticulous and careful consideration.