Comparison Of Left Breast Modified Radical Operation After Three Dimensional Conformal Intensity Modulated Radiotherapy And Electron Beam Radiotherapy Planning Dosimetry

Objective:The dose distribution of left breast modified radical resection of comparative advantage after three dimensional conformal IMRT and conventional electron beam radiotherapy plan and the insufficiency, provide the necessary clinical basis for radical operation of breast cancer after radiotherapy in clinical work, choose an appropriate plan.Methods:Randomly selected in 2013 October ~2014 year in June admitted to hospital for treatment of 50 cases of modified radical mastectomy of breast cancer patients after the left side, 50 cases of left breast cancer patients after operation all use CT positioning in CT image outline of the chest wall, internal mammary area, the heart and ipsilateral lung and contralateral breast. Each patient using three dimensional treatment planning system design of conventional electronic line plan and three-dimensional conformal compared IMRT plan, prescription dose was 50Gy/25 times of chest wall. Using the dose volume histogram(DVH) to compare the difference of the two dosimetry.Results:Three dimensional conformal PTV volume percentage of adjustable accept >95% prescription dose radiotherapy planning target area(VD95%), and the conformal index(CI), homogeneity index(HI) significantly outperforms the electronic line plan,but VD105%, VD110% than the conventional electron line plan low, had statistical differences(P<0.05). Heart tissue to accept more than 30 Gy dose irradiation of the three dimensional conformal and intensity-modulated plan and electronic line plan heart percentage of heart volume(V30), average dose in patients with pulmonary(Dmean) no significant difference(P>0.05). Three dimensional conformal and intensity-modulated plan heart V40, ipsilateral lung V20, double lung V20 was significantly lower than that of the electronic line plan, but the heart of Dmean,ipsilateral lung V5, lung Dmean higher than the electronic line plan. To dose contrast side breast, electronic line planning technology of contralateral breast basically no irradiation dose, three dimensional conformal and intensity-modulated plan of contralateral breast Dmean:(1.39 + 0.55) Gy. V1(%):(14.48 + 87.05)%。Conclusion:Using three-dimensional conformal intensity modulated radiotherapy and electron beam radiotherapy plan dosimetric comparison radical resection of left breast cancer, three dimensional conformal intensity modulated radiotherapy can better improve the homogeneity of dose distribution of target, more conformal, can reflect the tumor the advantages of individual treatment, reduce the lung and heart irradiated volume and dose, to some extent reduce the radiation damage caused by radiotherapy in patients at the same time, make the patient clinical benefit maximum.