The impact of pre-radiotherapy surgical intervention on radiation-induced lung injury

Abstract

7274 Background: To assess the impact of thoracic surgical intervention prior to RT on the later development of symptomatic RT-associated lung injury. Methods: From 1991–2003, 251 patients with lung cancer were enrolled on a prospective study to assess RT-induced lung injury. All patients received 3D-planned external beam RT at Duke. 184 patients with >6 month follow-up were eligible for this analysis. 58 patients (32%) had surgical intervention (thoracotomy without resection, wedge resection, lobectomy, and pneumonectomy) prior to RT. The rates of grade ≥2 symptomatic pneumonitis in patient subgroups, based on the type of pre-RT surgery, were computed and compared via Fishers Exact Test. To consider the confounding factor of irradiated lung volume, patient subgroups were further defined based on the mean lung dose. Thus, within a defined range of mean lung doses, the rates of pneumonitis in the different surgical groups were compared. Results: See Table. In the lobectomy group, the pneumonitis rates in patients with right and left sided tumors were 1/9 and 6/14, respectively (p= 0.18).Conclusions: For patients undergoing surgical intervention, the incidence of pneumonitis appears highest in the lobectomy group; especially for left-sided lesions. The rate of pneumonitis appears lowest in patients with a prior pnemonectomy, likely due to their lower mean lung doses. Additional work is needed to better understand the impact of pre-RT surgery on the later development of symptomatic radiation pneumonitis. Supported by NIH R01 Grant CA69579. Thanks to UNC for PLUNC software. No significant financial relationships to disclose.