219PPneumonitis and fibrosis after breast cancer radiation

Abstract Background Breast cancer(BC) radiation therapy(RT) reduce local recurrence, BC mortality and improves overall survival, but may induce lung damage ranging from radiological changes only to respiratory failure. Lung toxicity may present as radiation pneumonitis (RP) 3-6 months after treatment and radiation fibrosis (RF) after 6-12 months. The aim of the study is to describe the occurrence of RP and RT after conventional RT and examine their potential predictors. Methods 250 patients were entered in a prospective cohort study from February 2007 to October2008. All patients received standard postoperative 3D conformal radiation therapy (2 Gy x 25) for BC. Pulmonary High Resolution Computer Tomography and clinical examinations were performed before RT and 3, 6 and 12 months after radiation treatment. Smoking habits were reported by patients. Estimated lung dosevolums (V20, V30, D25) were retrieved from the doseplan system(Oncentra). Patient- and treatment-related factors were registered by oncologists at start. Evaluation of RP and RF were performed by a radiologist according to NCÍs CTCAE (version 3.0 ). Predictors of RP and RF were evaluated by univariate and multivariable logistic regression. Patient reported outcomes were measured using EORTC QLQ-C30. Results The occurence of RP 3 months after radiation therapy was 76.6% and RF 12 months after treatment was 90.5 %. 17.5% had symptomatic RP and 17.1% symptomatic RF, mainly as grade 1. In We identified correlation between mastectomy and symptomatic RP (OR = 2.41 p