Dosimetric Comparison Of Lung Toxicities In Patients With Upper/Mid Esophageal Cancer Treated With 3DCRT And IMRT

objective:Comparing the Radiation induced Pulmonary Injury of 3D-comformal radiation therapy and step-and-shoot IMRT by using three dimensional treatment planning system, explore the ideal radiation techniques for the treatment of upper/mid esophageal carcinoma.Methods:eight patients of upper/mid esophageal carcinoma were selected for a retrospective treatment-planning study by using ADAC system. Four different methods of radiotherapy planning were developed for each case, which were five fields 3D-CRT(CRT5),seven fields 3D-CRT(CRT7),five fields IMRT(IMRT5),seven fields IMRT(IMRT7). Assuring PTV95 reached prescription dose and assesing the lung MLD,V5,V10,V20,V30 of the different plannings by dose volume histogram(DVH). All statistics were conducted by software SPSS 11.5.Results:CRT5 plan reduced lung V10 (P=0.006) as compared to CRT7, lung V5,V20,V30 and Mean of lung have no statistical difference between them (P) 0.0083);IMRT plan has no significant difference between 5 fields and 7 fields concering the parameters of lung.the lung V20,V30,Meam of step-and-shoot IMRT is lower than 3D-CRT, while the lung V5 of 3D-CRT is lower than IMRT,the difference is significance.Conclusion:Compared to 3DCRT,IMRT reduce the mean dose of lung,V20 and V30; it is better in lung tissue sparing;when 3DCRT and IMRT technique were used,there were no difference of 5-field and 7-field technique in protection of lung tissues...