Meta-Analysis of the Effect of Clinical Target Volume for Three Dimensional Conformal Radiotherapy for the Treatment of Esophageal Carcinoma

Objective To evaluate the clinical efficacy and toxicities of the three-dimensional conformal radiotherapy for esophageal carcinoma by analyzing the different clinical target volume. Methods An electronic search was performered in American medical literature index （MEDLINE）, China national knowledge infrastructure（CNKI） digital library, China biomedicine literature database（CBM） and Chinese science and technology periodical database （VlP）. The trials were collected and evaluated according to the inclusion and exclusion criteria. The meta-analysis was performed for the results of homogeneous studies by RevMan 5.1.6 software. Results The meta-analysis included 5 trials. A total of 405 patients were included in the analysis. There was no statistically significant difference in 1-year survival rate between the experimental group and the control group with RR 1.05, 95%CI （0.65,1.71）, P=0.83; the similar results also were found in 1-year locoregional control rate with RR 0.92, 95%CI （0.57, 1.50）, P=0.75; However the radioactive pneumonia, radiation esophagitis for the two groups had statistical significant difference with RR 1.79, 95%CI （1.14,2.82）, P=0.01 and RR 1.98, 95%CI （1.11,3.51）, P=0.02, respectively. Conclusion Compared with control group, the experimental group based on large radiation field did not improve 1-year survival rate and 1-year locoregional control rate of patients, but increased higher incidence of radioactive pneumonia and radiation esophagitis in patients. In the radiotherapy of esophageal carcinoma, the results of this study including few cases that needs a larger sample, multi-center randomized controlled trials to be evidenced.