The effects of tangential radiotherapy on lung clearance in breast cancer patients.

Abstract

The aim of this study was to investigate the effects of tangential radiotherapy (RT) on lung clearance in the patients with breast cancer by using (99m)Tc-DTPA aerosol scintigraphy. Thirty-three female patients [non-smoker: 20, ex-smoker: 13] performed surgery and systemic chemotherapy for breast carcinoma [47+/-13 years] were included in the study. All patients underwent (99m)Tc-DTPA aerosol scintigraphy prior to RT (pre RT), midway through RT (mid RT) and after RT (post RT). Total dose was 50 Gy in modified radical mastectomy and 60 Gy in lumpectomy (2 Gy/fraction). Posterior dynamic images of lungs were obtained immediately after the inhalation of (99m)Tc-DTPA aerosol. Pulmonary function tests were normal in three measurements for all cases. In the ex-smokers, there was no significant difference among pre RT, mid RT and post RT clearance values in both lungs. Pre RT lung clearance in non-smoker group did not differ from that in ex-smokers. However, the lung clearance for non-smoker group showed significantly increase following RT. In this study, we observed that tangential radiotherapy caused an increase in the lung clearance in the cases of non-smokers even in non-irradiated lung, and that the effect of RT on lung clearance was closely depended on smoking habit before RT.