Risk Factors Of Radiation Pneumonitis In The Patients With Non-Small Cell Lung Cancer Treated By Concomitant Chemoradiation Therapy: Tog/Trod Lung Cancer Study Group

To evaluate the clinical and DVH parameters that increase radiation pneumonitis in Turkish locally advanced NSCLC patients treated by concomitant chemoradiation therapy from nationwide multicentric data analyses. Records of the 202/255 eligible patients from 7 different centers of Turkey were retrospectively reviewed. Age, gender, performance status, body weight, stage, tumor localization, tumor size, histology, chemotherapy scheme, smoking status, comorbid diseases, radiation therapy technique, and some DVH parameters (CTV, PTV, V5, V10, V20, and MLD) were reanalyzed. RTOG/EORTC pulmonary toxicity score was used for pneumonitis grading. X2 test was performed for statistical analyses. Median follow-up was 13 months (5-77). Ninety percent of the patients were male and median age was 60 years (31-83). 14 patients were T1, 60 T2, 60 T3 and 66 were T4 tumor. 71% of the patients had epidermoid carcinoma. Platinum derives were used for the 65% of the patients. 127 patients were treated by conformal radiation therapy and 75 were irradiated by IMRT and the median radiation therapy dose was 61.2Gy (45-66.6). There were 69 patients with grade I, 69 patients with grade II, 14 patients with grade III, 1patient with grade IV and 1 grade V pneumonitis. Median time to pneumonitis after treatment was 3 months (1-12). Cigarette smoking patients (P=0.001), patients treated with cisplatinum+etoposide (P16.5Gy (P=0.002), V10>45% (P=0.003) and V20>30% (P=0.011) had statistically more risk of radiation pneumonitis. The patients who had MLD>16.5Gy pneumonitis risk was increased by 3.3 times and V20>30%, it was increased by 3.6 times. No other factors were found to be a significant risk factor for pneumonitis. In Turkish patients with NSCLC, we could not find relationship between any host-disease factor and pneumonitis risk except smoking. The most significant factors for radiation pneumonitis were found to be MLD>16.5Gy and V20>30%.