Volumetric-modulated arc therapy as an alternative to intensity-modulated radiotherapy for primary tumors of advanced non–small-cell lung cancer: A multicenter retrospective analysis based on propensity score matching

Abstract

Purpose: To investigate the effect of volumetric-modulated arc therapy (VMAT) versus intensity-modulated radiotherapy (IMRT) for advanced non–small-cell lung cancer (NSCLC). 
 Methods: Cases in which the primary tumors were treated with IMRT or VMAT as initial intervention in stages III and IV NSCLC patients from September 2008 to March 2020 were retrospectively analyzed. Propensity Score Matching (PSM) was used to assess the efficacy and toxicity of the two radiotherapy techniques. 
 Results: A total of 637 patients were included, out of which 483 cases were treated with IMRT, while 154 received VMAT. A total of 308 patients were selected after PSM. Patients who were having acute radiation esophagitis and pneumonia treated with VMAT had a lower percentage than those treated with IMRT (p < 0.05) before PSM. However, there was no significant difference in grades 3 - 4 toxicity (χ2 = 2.77, p = 0.096). There were also no significant differences in the primary endpoints between the two groups after PSM (p > 0.05), while for secondary endpoints, all lung V5, and V20, mean lung dose and heart V30, heart V40, mean heart dose in all patients and stage N2 patients in VMAT after PSM were significantly lower than those of IMRT (p < 0.05). 
 Conclusion: Radiation therapy of A-NSCLC primary tumors using VMAT and IMRT seem to produce similar efficacy. The volume parameters of normal tissues and organs is significantly lower in VMAT, especially in patients with stage N2. Therefore, VMAT may be more beneficial for reducing radiation damage in normal tissues and organs.