Clinical research The analysis of prognostic factors affecting post-radiation acute reaction after conformal radiotherapy for non-small cell lung cancer Michał Spych1,2, Leszek Gottwald3, Małgorzata Klonowicz2, Michał Biegała4, Robert Bibik2, Jacek Fijuth1,2 1Radiotherapy Department, Chair of Oncology, Medical University of Lodz, Poland 2Teleradiotherapy Department, Regional Centre of Oncology, Copernicus Memorial Hospital, Lodz, Poland 3Palliative Care Unit, Chair of Oncology, Medical University of Lodz, Poland 4Medical Physics Department, Regional Centre of Oncology, Copernicus Memorial Hospital, Lodz, Poland Submitted: 27 October 2008 Accepted: 10 September 2009 Arch Med Sci 2010; 6, 5: 756-763 DOI: 10.5114/aoms.2010.17092 Copyright © 2010 Termedia & Banach A b s t r a c t Introduction: The aim was to evaluate the risk of acute side effects in the lung after 3-dimensional conformal radiotherapy (3D-CRT) in patients treated for non- small cell lung cancer (NSCLC). An attempt was made to single out clinical factors and factors related to treatment technique which may induce acute post- radiation pneumonitis. Material and methods: The analysis concerned 34 consecutive patients who underwent radical radiation therapy for NSCLC. Intensity of early toxicity was evaluated using modified RTOG/EORTC toxicity score. The endpoint for this analysis was the occurrence of radiation pneumonitis of grade 2 or higher. Factors related to treatment techniques were included in the statistical analysis. Results: Fifty-three percent of patients included in the study suffered from acute post-radiation pneumonitis. The results of the study revealed the existence of lung tissue sensitivity to low doses of ionizing radiation. The multivariate analysis showed that total lung volume receiving a low dose of 10 Gy increased the risk of post-radiation pneumonitis (p = 0.01). Conclusions: Acute post-radiation pneumonitis was a relevant clinical problem in patients who underwent radical radiotherapy for non-small cell lung cancer. The lung volume receiving a dose of 10 Gy was the most important dosimetric factor which influenced the post-radiation acute pneumonitis. Key words: NSCLC, conformal radiotherapy, post-radiation pneumonitis. Introduction The goal of radiotherapy is to cure cancer locally without excessive toxicity. The optimal way to achieve this goal is to precisely deliver an irradiation dose to the target volume, and no or a minimal dose to the uninvolved normal tissues and structures (organs at risk). Numerous studies suggest that higher irradiation dose results in better disease-free survival. In many tumours, such as carcinoma of the uterine cervix, prostate, and lung cancer, higher local control is correlated with increased survival. Complete surgical resection is the most effective initial treatment for patients with early stage non-small cell lung cancer (NSCLC). Local relapses Corresponding author: Michał Spych, MD, PhD Radiotherapy Department Chair of Oncology Medical University of Lodz Paderewskiego 4 93-509 Lodz, Poland Phone: +48 42 689 55 51 Fax: +48 42 689 55 52 E-mail: spychmichal@o2.pl