Investigation of the feasibility of using kilovoltage cone-beam CT for accuracy dose calculation in esophageal cancer radiotherapy
WANG Jun-qi*, XU Zhi-yong, HU Wei-gang, Wu Zhao-xia, LI Long-gen, YANG Huan-jun
*Department of Radiation Oncology, Cancer Hospital of Fudan University;Department of Oncology, Shanghai Medical College of Fudan University;Shanghai 200032, China Corresponding author:XU Zhi-yong, Email:xzyong12@vip.sina.com
Abstract：Objective To investigate the dose calculation accuracy and feasibility of using kilovoltage cone-beam CT (KVCBCT) for esophageal cancer radiotherapy. Methods Hounsfield unit (HU) values and profile along the horizontal line of Catphan600 phantom in KVCBCT images acquired on Trilogy linear accelerator were compared to those in the planning CT. The KVCBCT value-density calibration curve was established. The intensity modulated radiotherapy plans were created on the planning CT images and copied to KVCBCT images．The dose distribution was recalculated by means of the KVCBCT value-density calibration curve in the treatment planning system. The dosimetric comparisons were performed between the KVCBCT and planning CT plans on the phantom and 10 patients with esophageal cancer. Results The KVCBCT value was stable with a maximum variation of 1.6%, and there was no significant time trend. CT value profiles showed good agreement within 1% variation except the peripheral regions. The dosimetric differences were less than 1.33% and 3.65% for the phantom case and the patient ones, respectively. The dose distribution comparison was also in good agreements. Conclusions The accurate dose calculation based on KVCBCT for esophageal cancer is feasible. The KVCBCT images can be used for monitoring the dosimetric changes during the treatment.
WANG Jun-qi*,XU Zhi-yong,HU Wei-gang et al. Investigation of the feasibility of using kilovoltage cone-beam CT for accuracy dose calculation in esophageal cancer radiotherapy[J]. Chinese Journal of Radiation Oncology, 2012, 21(5): 455-459.
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2012, Vol. 21 
