Abstract

Info

Title:: Comparison of cone beam computed tomography calibrations based on soft tissue grey value and implanted markers in image-guided radiotherapy for bladder cancer

Author(s):: TIAN Long1; XI Qiang1; ZHAO Xin1; LIU Yuexia2; ZHANG Zunhao3; 1. the First Affiliated Hospital of Hebei North University, Zhangjiakou 075000, China; 2. Zhangjiakou Educational College, Zhangjiakou 075000, China; 3. the First Hospital of Hebei Medical University, Shijiazhuang 050000, China

Keywords:: ; Keywords: bladder cancer; cone beam computed tomography; image-guided radiotherapy therapy; soft tissue grey value; implanted markers

Abstract:: Abstract: Objective The X-ray volume imaging system of cone beam computed tomography can perform various ways of calibration. This study aims to evaluate and compare the accuracy of calibrations based on soft tissue grey value and bladder implanted markers. Methods All the patients receiving radiotherapy guided by cone beam computed tomography images were divided into two groups, namely experimental group (automatic calibration based on soft tissue grey value) and reference group (manual calibration based on bladder implanted markers). After the accuracy of implanted markers was confirmed, we compared the differences between two calibration methods in three-dimensional spatial vectors and left-right, superior-inferior, anterior-posterior directions. Results The mean differences between two calibration methods in three-dimensional spatial vectors and left-right, superior-inferior, anterior-posterior directions were 0.65, 0.03，0.45 and 1.67 cm, respectively. Conclusion In the image-guided radiotherapy for bladder cancer, the accuracy of automatic calibration based on soft tissue grey value is lower than that of the manual calibration based on bladder implanted markers. Avoiding implanted markers, new image calculations and analysis methods are the future development trends.