The clinical effects of low-dose splenic irradiation combined with chest three-dimensional conformal radiotherapy on patients with locally advanced non-small-cell lung cancer: a randomized clinical trial

OBJECTIVE The objective of this study was to explore the clinical effects of low-dose splenic irradiation on locally advanced non-small-cell lung cancer (NSCLC) patients. METHODS Thirty-eight patients with stage III NSCLC were randomly divided into a control group and a combined treatment group. The control group only received chest three-dimensional conformal radiotherapy, while the combined treatment group received low-dose splenic irradiation followed by chest three-dimensional conformal radiotherapy after 6 hours. T lymphocyte subsets of the blood cells were tested before, during, and after treatment once a week. The side effects induced by radiation were observed, and a follow-up was done to observe the survival statistics. RESULTS The ratio differences in CD4(+) cells, CD8(+) cells, and CD4(+)/CD8(+) before and after treatment were not statistically significant (P>0.05) in both the groups. The immune indexes were also not statistically significant (P>0.05) before and after radiotherapy in the combined treatment group. However, the numbers of CD4(+) cells and CD4(+)/CD8(+) ratios before radiotherapy were higher than after radiotherapy in the control group. There were no differences in the incidence of radiation toxicities between the two groups; however, the incidence of grade III or IV radiation toxicities was lower, and the dose at which the radiation toxicities appeared was higher in the combined treatment group. The total response rate was 63.16% (12/19) in the combined treatment group vs 42.11% (8/19) in the control group. The median 2-year progression-free survival (15 months in the combined treatment group vs 10 months in the control group) was statistically significant (P<0.05). The median 2-year overall survival (17.1 months in the combined treatment group vs 15.8 months in the control group) was not statistically significant (P>0.05). CONCLUSION Low-dose radiation can alleviate the radiation toxicities, improve the short-term efficacy of radiotherapy, and improve the survival of locally advanced NSCLC patients.