유방암환자의 전유방절제술 후 표준치료기법과 세기조절 방사선치료기법에 관한 비교연구

Abstract

Purpose: To tried to find better plan between intensity modulated radiation therapy plan and the standard plan from the breast cancer patients who took a modified radical mastectomy. When the planning target volume include chest wall, supraclavicular nodes, and internal mammary nodes, a significant volume of the heart and the ipsilateral lung may received high radiation doses, which may result in late complications. The value of intensity modulated radiation therapy to avoid the heart and ipsilateral lung dose was studied. Materials and methods: Chest wall, supraclavicular nodes, and internal mammary nodes, and normal tissues were contoured for 10 patients previously treated with the radiation therapy after the modified radical mastectomy for the breast cancer. With eleven- beam, intensity modulated radiation therapy plans were developed and compared with standard plans. Conformity index, homogeneity index and doses to normal tissues were compared. Results: Intensity modulated radiation therapy plans were significantly improved homogeneity (1.11 vs. 2.47), conformity (0.99 vs. 0.54), volum of the heart receiving more than 30 Gy (V30-heart) (4.6% vs. 16.96%), and volume of lung receiving more than 20 Gy (V20-lung) (22% vs. 27%) in left breast cancer patients. And intensity modulated radiation therapy plans were improved homogeneity (1.11 vs.3.35), conformity (0.99 vs. 0.5), and volume of lung receiving more than 20 Gy (V20-lung) (27% vs. 28%) in right breast cancer patients also. Conclusions: Intensity modulated radiation therapy plan was better for the breast cancer patients with the modified radical mastectomy. The heart and the ipsilateral lung volume receiving high doses were decreased, except the low dose regions.