Dosimetry Study Of Static IMRT、VMAT And Tomotherapy Radiotherapies Plans For Patients With Upper-thoracic Esophageal Carcinoma

[Objective] To compare the difference of Dosimetry Stady of sIMRT (static intensity modulated radiotherapy), VMAT (volumetric modulated arc therapy) and TomoTherapy plans for patients with upper-thoracic esophageal carcinoma.[Method]6 patients with upper-thoracic esophageal carcinoma were theated by static IMRT of 7fields、VMAT with a single arc and TomoTherapy of common modulate intensity. The difference of exposure dose between target area and critical organs was compared by the maximal dose of plan target volume, the minimal dose of plan target volume, the mean dose of plan target volume, V95, Heterogeneity Index and Conformity index. To compare the different dosimetry of OARs. To campare the different duration of treatment delivery time and monitor units.[Results]1.The TomoTherapy plans were the best,yet sIMRT plans were the worst on V95、CI and HI of targets.2.The protect to OARs is better in TomoTherapy plans than Static IMRT plans.In TomoTherapy plans spinal cord has much lower Dmax and the data has statistics difference.When tomoTherapy plans have lower volume in lung in V20、V30 and higher volume in V5、V10, the data has not statistics difference.3.The treatment delivery time of VMAT is lower than Static IMRT and TomoTherapy,and the data has statistics difference.[Conclusion]Three types of plans can all achieve the clinical dosimetric demands, but TomoTherapy has the best performance on V95、CI and HI. V MAT is most efficient regarding the delivery time and total MUs.