Clinical Research Of Hypofractionated Three-dimensional Conformal Radiation Therapy In Non-small Cell Lung Cancer

Objective:The purpose of this study is to analyze the effect of hypofractionated three-dimensional conformal radiation therapy for non-small cell lung cancer, and evaluate the short efficacy, long term survival and adverse effects.Methods:From January2001to December2006, the clinical datas of127cases underwent three-dimensional conformal radiation therapy were retrospectively analyzed. Among them,54received hypo-fractionated three-dimensional conformal radiation therapy(HF group),73were given conventional fractionated three-dimensional conformal irradiation (CF group).HF group:30of which first treated by conventional separation radiotherapy to the dose4000-5000cGy, later treated by hypo-fractionated radiatherapy,300-400cGy a time, once every other day, total prescribe dose6000-7l00cGy, BED7250-8730cGy, and24of which treated by hypo-fractionated radiatherapy,250-500cGy a time, once a day or every other day, total prescribe dose4400-7250cGy, BED6160-9062.5cGy.The median BED in HF group was7950cGy. CF group:1.8-2Gy per fraction,5fractions per week, total prescribe dose5000-7000cGy, BED6000-8400cGy, median BED was7000cGy. The short efficacy, survival outcome and radiation-induced pulmonary injury in both groups were analyzed.Result:1.The overall response rate (CR+PR) was70.87%, composed of27complete response (CR),63partial response (PR), and those of them in HF group and CF group were81.48%,18,26and63.01%,9,37, respectively. The effective rate of HF group was superior to CF group (P=0.015).2. For the whole group, the1-year,3-year and5-year overall survival (OS) rates were67.1%,26.6%,13.5%, respectively. The median survival time (MST) was22months. The l-year,3-year,5-year OS rates and MST in HF group were67.8%,35.6%,23.2%,24months, and those of the CF group were66.4%,19.0%,5.6%,20months, respectively. There were no statistically significant differences existed between HF group and CF group(x2=3.291, P=0.070). Stratified analysis by TNM clinical stage showed that, in early stage(stage I and stage Ⅱ), the OS of HF group was superior to CF group (%2=4.154, P=0.042), but in stage III and stage IV, there was no statistical difference(x2=0.096, P=0.757). Stratified analysis by tumor volume showed that, when the tumor volume was≤90cm3the OS of HF group was superior to CF group ((2=6.242, P=0.012), but in larger tumor volume(>90cm3),there was no statistical difference(x2=0.000, P=0.985).3. The results of univariate and multivariate analyses revealed that tumor volume, BED, chemotherapy were the independent prognostic factors for OS in NSCLC(P<0.05), smaller tumor volume, the improvement of biological effective dose, and radiotherapy combined with chemotherapy may have some advantages in improving survival.4. The incidence of grade greater or equal to2radiation-induced pneumonitis was40.16%(51/127) for the whole group,37.04%(20/54) for the HF group, and42.47%(31/73) for the CF group. The overall lung fibrosis rate was17.32%(22/127),18.52%(10/54) in HF group, and16.44%(12/73) in CF group. No significant differences were noted in the aspects of radiation pneumonia and lung fibrosis between the two groups(P<0.05).Conclusion:Compared with conventional fractionated irradiation, hypofractionated radiation therapy can be shorten the treatment time, increase the gains ratio of radiotherapy, and improve short efficacy. In early stage and small tumor volume of NSCLC the OS was higher, but the radiation toxicity did not increase.There were no significant differences in OS and radio-pulmonary injury for localy advanced NSCLC.