Hemogas analysis was performed with blood sampling from the radial arteria or omeral arteria and analysed with the ABL 520 blood selleck products gas analyzer system. The PaO2,ST (i.e. standard) was standardized to a PaCO2 of 40 mmHg from the PaO2 and PaCO2 values and corrected for the effect of hyperventilation [20]. The evaluation of pulmonary functionary was performed on 38 patients (one patient refused post-radiotherapy PFTs and one-year post-radiotherapy CT). Nine patients

were, or had been in the past, smokers. Toxicity Radiation toxicity was evaluated daily during therapy, once a week for one month after radiotherapy completion, every 3 months for the first year and from then on every six months. The National Cancer Institute Common Toxicity Criteria, version 2, was used to assess the acute toxicity [21]. The SOMA/LENT

scoring system was used for the assessment of late sequelae [22]. The National Cancer Institute Common Toxicity GS-1101 mouse Criteria, version 4, was used to assess the lung toxicity based on pulmonary function tests [23]. CT scan evaluation In order to evaluate density of omolateral lung, a chest CT scan (with the patient in the same treatment position) was planned about one year post-radiotherapy. Out of 39 patients, 38 underwent chest CT scans before (1 patient refused one-year post-radiotherapy CT and post-radiotherapy PFTs). A radiologist with specific experience (blinded to the side of irradiation) was asked to assess differences between the two lungs and to score CT- lung alteration according to Nishioka et al. [24] scoring system, summarized as follows. Grade 0: no significant changes in the radiation fields; Grade 1: only pleural thickening is seen in the radiation fields; Grade 2 pulmonary changes (plaque-like or heterogeneous Reverse transcriptase density) are seen in less than 50% area of the radiation fields; Grade 3: pulmonary changes are seen in more than 50% area of the radiation fields. We also evaluated the radiation induced

pulmonary density changes by a modified Wennemberg et al. [25] CT-based method. The CT scan performed before radiotherapy for treatment planning and the one-year follow-up CT scan were considered. On both sets two levels were examined: CT slices corresponding to the isocenter and the boost area. For lung evaluation, regions of interest of about 1 cm diameter immediately below the thoracic wall were drawn in the irradiated and non irradiated lung and in the pre-radiotherapy and post-radiotherapy (1 year after) CT scan. The mean density and the standard deviation within the area of interest were calculated by TPS tools. Density was evaluated in Hounsfield Units (HU) representing the mean attenuation of the tissue examined, in a scale where -1000 and 0 are the air and the water density values, respectively.