Purpose: To compare brachytherapy to external beam radiation therapy (EBRT) with respect to overall survival (OS) and disease-specific survival (DSS) among NSCLC patients undergoing limited surgical resection.
Methods: All cases of T1-4 N0 M0 NSCLC undergoing limited resection and either brachytherapy or EBRT diagnosed between 2004 and 2014 were extracted from the Surveillance, Epidemiology, and End Results database. Chi-square test and Fisher's exact analysis were used to analyze categorical variables while Student's t-test was used to analyze continuous variables. Univariate analysis to assess for differences in survival with respect to covariates was performed with the log-rank test. Multivariable analysis was performed with Cox proportional hazards regression models among the entire cohort and after sub-stratification by T stage.
Results: Among 543 patients, 471 underwent EBRT and 72 underwent brachytherapy. Brachytherapy demonstrated improved OS and DSS on univariate analysis as compared to EBRT (p < 0.05). Cox regression also demonstrated improved OS and DSS with brachytherapy (HR 0.604; 95% CI [0.380; 0.961] and HR 0.524; 95% CI [0.303; 0.908], respectively). Sub-cohort analysis demonstrated significant improvement in survival only among patients with T1 disease with similar survival between brachytherapy and EBRT among higher stage disease.
Conclusions: Patients undergoing brachytherapy for T1-T4, N0, M0 NSCLC demonstrated at least similar survival as compared to those undergoing EBRT among patients undergoing limited resection. Improved survival was demonstrated among patients with T1 disease.
Keywords: Brachytherapy; Lung; SEER; Sublobar.