Clinical Application Of Equivalent Uniform Dose In IMRT Breast Cancer Therapy

Purpose: to investigate wether intensity-modulated radiotherapy (IMRT) optimized using theequivalent uniform dose(EUD),can increse the safe dose to tumors and more perfect dosedistribution,as well as reduse the dose to other organs at risk(OAR),compared with IMRT optimizedusing Dose-volume-Hisgram(DVH).Methods:100patients who surfered from lung cancer and100patients who surfered from left-beastcancer were selected into experiment. then10patients of experiment were enrolled.After scan with GE high-speed and large-aperture CT simulator, the images were sent to ADACtreatment planning system through LAN. according ICRU62,doctor outlines the PTV、CTV andOARS. Such as lungs、heart、spinal cord. then physictist gives two plans, one was optimased with DVand the other was optimased with EUD (tips: these two plans should have the same energy、samederect of incidence、same prescription).after the optimazation was finished.DVHs can used as aevalued tools, dose distribution, max dose, mean dose were compared between this two plans.Results from the DVHs and dose distribution, we can see,in plans of non-small cell lung cancer, plansbased on DV and plans base on EUD. the PTV95%of prescription were97%and96%,respectively.the maximun dose (D1%) of both two plans are68Gy,mindose are55Gy.the average dose were58Gy;the minnimun dose in spinal cord were43Gy both of them. for the whole lung, the difference ofthem was large. with the average dose of lung was15Gy and12Gy,espeacively.18%and14%of V30in whole lung and15%and12%of V20.In left-breast cancer, there was no difference in CI and HI. butin the plan bas ed on EUD. difference in V40of heart, varies was large. and the V40decreased4%and6%of average dose.Conclusion compared with DV, the IMRT plan based on EUD can protect the OARs better. it candecreases the dose distribution. Thus it can reduce the complications of radiotherapy significant...