Fifty-sixth annual meeting of the American association of physicists in medicine
SU-E-T-06: A Comparison of IMRT Treatment of Esophageal Carcinoma in Elekta-Precise and Varian23EX Linac
To compare and analyze the characteristics of static intensity-modulated radiotherapy (IMRT) plans designed on Elekta and Varian Linac in different esophageal cancer(EC), exploring advantages and disadvantages of different vendor Linac, thus can be better serve for clinical.
Twenty-four patients with EC were selected, including 6 cases located in the cervical, upper, middle and the lower thorax, respectively. Two IMRT plans were generated with the Oncentra planning system: in Elekta and Varian Linac, prescription dose of 60Gy in 30 fractions to the PTV. We examined the dose-volume histogram parameters of PTV and the organs at risk (OAR) such as lungs, spinal cord and heart, and additional Monitor units(MU), treatment time, Homogeneity index(HI), Conformity index(CI) and Gamma index comparisons were performed.
All plans resulted in abundant dose coverage of PTV for EC of different locations. The doses to PTV, HI and OAR in Elekta plans were not statistically different in comparison with Varian plans, with the following exceptions: in cervical, upper and lower thoracic EC the PTV's CI, and in middle thorax EC PTV's D2, D50, V105 and PTV-average were better in Elekta plans than in Varian plans. In the cervical, upper and the middle thorax EC, treatment time were significantly decreased in Varian plans as against Elekta plans, while in the lower thoracic EC treatment time were no striking difference. MUs and gamma index were similar between the two Linac plans.
For the the middle thorax EC Varian plans is better than Elekta plans, not only in treatment time but in the PTV dose; while for the lower thorax EC Elekta plans is the first choice for better CI; for the other part of the EC usually Elekta plans can increase the CI, while Varian plans can reduce treatment time, can be selected according to the actual situation of the patient treatment.