Competitive Advantage Applying the Volume-Modulated Arc Techniques to Radiotherapy of Upper Esophageal Carcinoma
P Ma*, L Wang, N Lu, Y Xu, J Dai, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Beijing, BeijingSU-E-T-710 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
Purpose: To access if VMAT can integrate the advantages of both sIMRT and IMRT for treatment of upper esophageal carcinoma.
Methods:10 patients with upper esophageal carcinoma were randomly chosen in the retrospective study. sIMRT, IMRT and VMAT plans were generated to deliver 60 Gy in 30 fractions to the planning target volume (PTV). With the same Target and OAR dose constrains, but different beams arrangements (5,7equispaced coplanar beams and 2 complete arc) parameters generated from three different plans for each case were then compared.
Results:For all patients, PTV D2% and HI were similar between the VMAT and IMRT techniques (p > 0.05) while for VMAT CI is superior to that of IMRT. Compared with IMRT and sIMRT, the mean dose de-livered and regions receiving a 20Gy radiation dose were reduced for lungs in VMAT (p < 0.05). For the latter Lung V20 and mean lung dose were reduced by 13% and 3%, respectively. MU was significantly reduced by 27% in VMAT comparing with that of IMRT. VMAT had better PTV coverage and OARs sparing than sIMRT, however mean dose to normal tissue is larger.
Conclusion: In VMAT for patients with upper esophageal carcinoma, using of VMAT significantly reduces the radiation MU and dose to the lungs compared with IMRT, and consequently saves the treatment time as same as sIMRT while reducing the incidence of radiation pneumonitis.