Outcomes between intensity-modulated radiation therapy versus 3D-conformal in early stage glottic cancer

Background: The purpose of this study is to evaluate practice patterns and outcomes between intensity-modulated radiation therapy (IMRT) and 3D-conformal radiation (3D-CRT) in early stage glottic cancer. Methods: The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database was used to identify and compare patient and disease profiles, mortality, and toxicity in patients with T1-2 larynx cancer undergoing definitive radiation (RT). Results: A total of 1520 patients underwent definitive radiation with 3D-CRT (n = 1309) or IMRT (n = 211). Non-white race, those with a Charlson Comorbidity Index ≥2, T2 disease, and those treated at community practices were more likely to undergo IMRT. Rates of IMRT increased from 2006 to 2015, while relative rates of 3D-CRT decreased. Two-year CSS was superior with 3D-CRT (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.22–0.65; p < 0.001). There was no difference in OS between 3D-CRT and IMRT (p = 0.119). Conclusions: Patients receiving 3D-CRT had improved CSS compared to IMRT with no difference in OS.