Comparative Effectiveness of Intensity-Modulated Versus 3D Conformal Radiation Therapy Among Medicare Patients with Stage III Lung Cancer

Introduction: The clinical benefit of intensity-modulated radiation therapy (IMRT) compared to 3D conformal radiation (3D-RT) has not been well established for locally advanced non-small-cell lung cancer (NSCLC). Methods: Using SEER-Medicare, we identified Medicare beneficiaries diagnosed with stage III NSCLC who received potentially curative (>= 25 fractions) thoracic IMRT or 3D-RT from 2002-2009. Overall survival and number of hospital days within 90 days of radiation were analyzed using Cox proportional hazard and negative binomial regression models, respectively. Propensity score adjustment was used to control for clinical and demographic variables associated with outcomes. Results: IMRT comprised an increasing proportion of conformal thoracic radiation for NSCLC, rising from 3.0% in 2002 to 26.8% in 2009. Use of IMRT varied significantly by year of diagnosis, facility type, and geographic region and was more likely to be used among patients receiving chemotherapy or with higher comorbidity scores. Among patients receiving potentially curative treatment, there was no difference in overall survival (propensity adj HR .99, p = 0.83) or number of hospital days in the 90 days following radiation start (propensity adj HR 1.15, p = 0.23). Conclusions: When radiation is used to treat locally advanced NSCLC, IMRT is increasingly preferred to 3D-RT. However, among patients receiving potentially curative radiation there was no significant difference in overall survival or time spent hospitalized following treatment.