비소세포성폐암의 동시 항암방사선치료 후 방사선폐렴 발생 인자에 대한 연구

Abstract

PURPOSE: To retrospectively evaluate the risk of radiation pneumonitis (RP) after 3-dimensional conformal radiotherapy (3D-CRT) with concurrent chemotherapy in locally advanced non-small cell lung cancer. METHODS: One hundred twenty-eight patients underwent fractionated 3D-CRT. Median dose of 66 Gy (range, 60-72 Gy) was delivered in 33 fractions (range, 28-39) over 6.5 weeks. All patients were treated with curative intent and received concurrent chemotherapy. Induction and consolidation chemotherapy was delivered in 10 and 9 patients, respectively. RP was graded by Radiation Therapy Oncology Group criteria. The association of RP and dose-volumetric parameters were analyzed using the chi-square test and the logistic regression analysis. The normal tissue complication probability (NTCP) was derived using the Lyman-Kutcher-Burman model. RESULTS: Of 128 patients, 68 (53.1%) experienced RP; 15 (11.7%) developed RP of grade 1; 22 (17.2%), grade 2; 27 (21.1%), grade 3; 2 (1.6%), grade 4; and 2 (1.6%), grade 5. Age, gender, performance status, smoking history, underlying lung disease, tumor location, and forced expiratory volume in 1 sec were not significantly associated with severe RP (grade 3 or greater). Univariate analysis revealed that mean lung dose (MLD), V5, V10, V20, V30, V40 and NTCP significantly correlated with severe RP. In multivariate analysis, NTCP was the most significant factor associated with severe RP (P<0.001). MLDs of 9, 14 and 18 Gy corresponded to NTCPs of 10%, 20% and 30%, respectively. CONCLUSIONS: NTCP is a useful predictor of severe RP after 3D-CRT with concurrent chemotherapy.