Study On IMRT, 3DCRT And Conventional Irradiation In Dosimetry Of Esophageal Cancer Radiotherapy

Objective: The aim of this study is to evaluate different radiotherapy plannings of esophageal cancer radiotherapy with 3D-treatment planning system, to compare sliding window IMRT,MIMiC-IMRT, 3DCRT, and conventional irradiation planning in dose of target volume and protection of normal important tissues, and to obtain which technique is better and selecting reasonable treatment methods for esophageal cancer .Methods: For the 10 esophageal cancer patients seven plannings were done with Eclipse 3D-treatment system and Peakcock treatment system。Every plan should satisfy the criteria of≥95% of the prescription dose in PTV.The differences of normal tissue dose were compared with DVH.Result: (1) The disadvantage of the conventional irradiation is the dose in PTV and CTV not enough. (2) When conventional irradiation technique was used for esophgeal cancer, the fields must be enlarge to meet the criteria of≥95% of the prescription dose in PTV. (3) 5-field 3D-CRT technique is the same as 7-field concerning the dose of heart and the dose of lung. (4) 5-field SMLC-IMRT technique is the same as 7-field concerning the dose of heart and the dose of lung. (5) CRT technique is the same as SMLC-IMRT concerning the maximum dose to the lung and lung V5,V10. The mean dose of lung and lung V20,V30 of SMLC-IMRT5 is lower than CRT ,the difference is significance(P<0.01)。(6)There were significant differences of lung V5,V10 and the mean dose of lung(all P<0.05)among the SMLC-IMRT and the MIMiC-IMRT,but the others are not significant. esophageal cance; Compared to SMLC-IMRT, 3DCRT increase the mean dose of lung;SMLC-IMRT is better to MIMiC-IMRT in lung tissue sparing...