Breast irradiation The effects of tangential radiotherapy on lung clearance in breast cancer patients * Dog ˘angu ¨n Yu ¨ksel a, * , Serdar Su ¨renko ¨k b , Seyfettin Ilgan c , Emel O ¨ ztu ¨rk c , Yu ¨cel Pak d a Department of Nuclear Medicine, Medical Faculty, Pamukkale University, Denizli, Turkey, b Department of Radiation Oncology, and c Department of Nuclear Medicine, Gu ¨lhane Military Medical Faculty, Ankara, Turkey, d Department of Radiation Oncology, Gazi University Medical Faculty, Ankara, Turkey Abstract Purpose: 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. Material and methods: Thirty-three female patients [non-smoker: 20, ex-smoker: 13] performed surgery and systemic chemotherapy for breast carcinoma [47G13 years] were included in the study. All patients underwent 99m Tc-DTPA aerosol scintigraphy prior to RT (preRT), midway through RT (midRT) and after RT (postRT). 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. Results: Pulmonary function tests were normal in three measurements for all cases. In the ex-smokers, there was no significant difference among preRT, midRT and postRT clearance values in both lungs. PreRT 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. Conclusion: 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. q 2005 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 77 (2005) 262–266. Keywords: 99m Tc-DTPA; Aerosol scintigraphy; Lung clearance; Radiation pneumonitis; Breast cancer; Radiotherapy; Smoking habits Tangential radiotherapy is an accepted treatment modality for breast cancer. However, radiation induced lung injury is a complication of this treatment [10,16]. The lung injury may progress to pneumonitis or fibrosis some- times [7,8]. The one of early changes in the lungs following radiotherapy is the alteration in the lung clearance [1,17,18]. It has been reported that impaired lung clearance values precede clinical and radiological findings of pneumo- nitis [11,18]. Technetium-99m labeled diethylenetriamine- pentaacetic acid ( 99m Tc-DTPA) aerosol scintigraphy is a sensitive and noninvasive method for evaluation of changes in lung clearance rate after radiotherapy [15,17–19]. The prolonged 99m Tc-DTPA clearance was observed after irradiation of hemithorax with single dose of 20 Gy [17]. On the other hand, there are few studies about changes in pulmonary clearance rate induced by tangential radiotherapy in subjects with breast carcinoma [5,9,14,18]. These studies generally did not focus the effects of different factors such as chemotherapy, surgery and smoking habits on lung clearance. In this study, our aim was to investigate the possible effects of tangential radiotherapy and of different variables such as radiation dose, chemotherapy, tamoxifen and smoking habit on the alteration of lung clearance in patients with breast cancer by using 99m Tc-DTPA aerosol scintigraphy. Material and methods Patients Thirty-three female patients (mean age: 47G13 years; range: 27–84 years) operated for breast carcinoma were enrolled in this study. Eligibility criteria were as follows: no clinical evidence of past or present lung disease such as tuberculosis, pneumonia, and having normal pulmonary function tests and chest radiography. All patients gave the informed consent. 0167-8140/$ - see front matter q 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.radonc.2005.10.013 * This study was presented orally in the 5th International Congress of Nuclear Oncology, Kus ¸adası, Turkey. Radiotherapy and Oncology 77 (2005) 262–266 www.thegreenjournal.com