Non-conventional radiotherapy versus conventional radiotherapy for inoperable non-small-cell lung cancer: A meta-analysis of randomized clinical trials

Background: The aim of this study was to evaluate the efficacy and safety of non-conventional radiotherapy versus conventional radiotherapy for inoperable non-small-cell lung cancer and to conduct a meta-analysis to compare these two methods of radiotherapy for inoperable NSCLC.

Methods: We included randomized controlled trials, which were compared with non-conventional radiotherapy with or without concurrent chemotherapy versus conventional radiotherapy with or without concurrent chemotherapy.

Results: Meta-analysis of 13 randomized controlled trials with a total of 2206 patients showed that the non-conventional radiotherapy group could significantly improve the objective response rate (OR 1.68, 95% confidence intervals (CI) 1.19-2.37) and overall survival of up to 1-year (OR 1.30, 95% CI 1.09-1.54), 2-year (OR 1.41, 95% CI 1.17-1.70), 3-year (OR 1.55, 95% CI 1.24-1.94), 4-year (OR 1.60, 95% CI 1.20-2.15), 5-year (OR 1.63, 95% CI 1.11-2.38); and local control rate in 1-year (OR 1.35, 95% CI 1.09-1.68), 2-year (OR 1.57, 95% CI 1.23-1.99), 3-year (OR 1.45, 95% CI 1.10-1.91) compared with the conventional radiotherapy group. With regard to the side effects, non-conventional radiotherapy was more likely to result in level III and IV radioactive esophagitis (OR 1.64, 95% CI 1.09-2.46), but there was no significant difference in the incidence of radioactive pneumonitis (OR 0.96, 95% CI 0.67-1.39). In the subgroup analysis we found late course accelerated hyperfractionated radiotherapy (LCHRT) could obviously improve 1-year OS (OR 2.29, 95% CI 1.29-4.06), 2-year OS (OR 4.22, 95% CI 2.03-8.77), 3-year OS (OR 2.49, 95% CI 1.24-5.02) and Objective response rate (OR 2.38, 95% CI 1.17-4.83). However, hyperfractionated radiotherapy (HRT) and accelerated hyperfractionated radiotherapy (AHRT) could not improve 1-, 2-, 3-year OS or OR compared with conventional fractionation radiotherapy.

Conclusions: Our findings indicate that NCRT could improve OR, reduce the risk of death by 1-5 years, and significantly increase level III and IV radioactive esophagitis incidence. The late course accelerated hyperfractionated radiotherapy (LCAHRT) group seemed to improve compared with the AHRT and conventional radiotherapy (CRT) groups.