[Factors predicting radiation toxicity in the treatment of three-dimensional conformal radiotherapy for lung cancer].

BACKGROUND: The lung and esophagus are always damaged during radiation on thoracic tumors to a certain extent. This study is to report the incidence of radiation pneumonitis and radiation esophagitis and to analyze the factors as predictors of radiation toxicity in the treatment of three-dimensional conformal radiotherapy (3DCRT) for lung cancer. METHODS: Between March 1999 and September 2003, 112 lung cancer patients treated with 3DCRT were reviewed at this Hospital. This population consisted of 87 men and 25 women, including 97 cases of non-small cell lung cancer and 15 of small cell lung cancer. The median age was 64 years old. Radiotherapy was delivered at 2Gy fraction, 5 fractions per week. The median total dose was 60Gy. RESULTS: Grade 2 or more acute radiation pneumonitis developed in 7.1% (8/112) of patients while grade 2 or more late radiation pneumonitis appeared in 1.8% (2/112) of patients. Acute radiation esophagitis was observed in 8.9% (10/112) of patients with grade 2. No clinical and physical factor was relative to acute radiation pneumonitis by univariate and multivariate analysis. In the entire population, the univariate analysis revealed that many parameters (pre-treatment weight loss more than 5%, chemotherapy and concurrent chemotherapy) were significantly associated with acute radiation esophagitis. Multivariate analysis revealed that pre-treatment weight loss more than 5% was the most important risk factor for acute radiation esophagitis (P= 0.016). CONCLUSIONS: No clinical and physical factor is relative to acute radiation pneumonitis and pre-treatment weight loss more than 5% is the most important risk factor for acute radiation esophagitis in this study.