The analysis of prognostic factors affecting post-radiation acute reaction after conformal radiotherapy for non-small cell lung cancer 0 1 0 2 3 No. of patients 3 15 7 9 34 0.00% 2.94% 5.88% 0.00% 8.82% 11.76% 11.76% 17.65% 2.94% 44.12% 2.94% 0.00% 17.65% 0.00% 20.59% 5.88% 5.88% 8.82% 5.88% 26.47% in the tumour bed and regional lymph nodes or distant metastases are the mechanism of relapse after curative resection [1, 2]. Radiation therapy is the primary treatment for NSCLC, either as adjuvant treatment after surgery or as radical treatment in patients with locoregional advanced, inoperable tumour. It was reported that high radiation doses were correlated with improvement of local control [3-5]. Radiation-induced pulmonary injury is one of the most common and serious complications in patients who receive high-dose radiation therapy for non-small cell lung cancer. The use of three- dimensional conformal radiotherapy allows for improved target volume coverage as well as better ability to spare normal lung tissue. Nevertheless, the percentage of patients who experience post- radiation pneumonitis fluctuates between 6% and 49% [6-20]. Several clinical factors as well as specific dose-volume histogram (DVH) parameters have been reported as risk factors for radiotherapy- related lung injury in NSCLC patients. Poor performance status, concurrent smoking, age, low haemoglobin concentration, concurrent chemo- therapy, history of chronic obstructive pulmonary disease (COPD), and poor pulmonary function before radiotherapy have been reported as common clinical factors related to post-radiation lung injury [17, 21-24]. Many studies have reported that the percentage volume of lung receiving more than some defined threshold dose and mean lung dose (MLD) are predictive factors for post-radiation acute lung toxicity. Most reported results in the literature are inconsistent. In this study we tried to express our opinion in the discussion. We herein report our study results of radiation-induced lung toxicity in a group of 34 patients with NSCLC, treated using three-dimensional conformal techniques. The aim of this study was to evaluate the risk of acute side effects in the lung after 3D-CRT in patients treated for 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 From September 2004 to March 2006, 34 consecutive patients were enrolled in a prospective study to evaluate pulmonary toxicity following 3D-CRT. They were treated in the Radiotherapy Department, Chair of Oncology of Medical University of Lodz. There were 25 males and 9 females in this group. The male : female ratio was 2.7 : 1. Patient’s age was in the range 48-81 years (mean 63.4 years; standard deviation [SD] 8.4; median 63.0 years; 95% confidence interval [95% CI] 60.7-66.0). The clinical stage evaluation, and qualification of patients for radiation therapy were established after conducting medical Arch Med Sci 5, October / 2010 757 examination, chest x-ray film in antero-posterior and lateral projection, chest computed tomography study, abdominal ultrasonography and bron- choscopy. The tumour size (the largest diameter defined in millimetres, measured in the chest computed tomography study) was in the range 20-85 mm (mean 45.3 ±18 mm; median 40.0 mm; 95% CI 39.7-50.8). In most cases, patients who were qualified for radical radiotherapy were in clinical stage III: frequency of stage IIIa and IIIb was 41% and 29% respectively. Seven patients (5 in clinical stage II and 2 in clinical stage I lung cancer) were disqualified from surgery because of other coexisting medical contraindications. Three patients in the analysed group (1 in clinical stage II and 2 in clinical stage I) did not consent to surgery. Clinical stage distribution according to TNM classification is presented in Table I. The haemoglobin concentration before treat- ment fluctuated between 10.3 g/dl and 15.9 g/dl (mean 13.3 ±1.51 g/dl; median 13.3 g/dl; 95% CI 12.5- 13.7). In the analysed group, patients’ performance status was evaluated using the Karnofsky Performance Scale (KPS). All patients were in very good or good general condition. There were 4 (12%) patients with 100% KPS. Sixteen (47%) and 14 (41%) patients were classified respectively as 90% and 80% KPS. Twenty-five (73.6%) patients underwent chemotherapy with a platinum-based regimen before radiation therapy. Twenty-one (61.8%) patients received cisplatin in a dose of 100 mg/m2 with etoposide 100-120 mg/m2 every 21 days. Four (11.8%) patients received cisplatin in monotherapy. The number of chemotherapy courses ranged between 2 and 5 (median 3.8 courses). In every case the diagnosis of non-small cell lung cancer was confirmed in histopathology examination. In the analysed group squamous cell carcinoma was diagnosed in 21 (61.8%) patients. Adenocarcinoma was recognized in 5 (14.7%) patients. The same Table I. Clinical stage according to TNM classification T/N N0 N1 N2 N3 patients 20.59% 20.59% 50.00% 8.82% 100.00% T1 T2 T3 T4 No. of 0 4 1 2 7 1 4 0 2 7 2 6 6 3 17