基于螺旋断层放疗摆位误差的外放边界研究

Study on the margin of PTV based on the setup error of helical tomotherapy

选取基于螺旋断层放射治疗的219例肺癌、食管癌和乳腺癌患者的摆位误差数据,分析摆位误差在患者左、右、进、出、腹、背6个方向的对称性,并对3种肿瘤在6个方向的摆位误差发生频率、误差发生率及摆位误差平均值进行差异性分析,研究根据x,y,z方向计算靶区外放边界的合理性。分析结果表明,摆位误差具有同轴异向的不对称性,基于6个方向计算的外放边界更加精准。

Select the setup errors of 219 patients with lung cancer,esophageal cancer and breast cancer based on helical tomotherapy(HT),analyze their symmetry in the six directions of left,right,in,out,abdomen,back,analyze the difference of the frequency,incidence rate of deviation and average value of setup errors of three kinds of tumors in six directions,and study whether the calculation of the margin from the CTV to the PTV based on the three directions of x,y,z is reasonable.The results of analysis indicate that the asymmetry of coaxial and anisotropy.Therefore,helical tomotherapy for chest tumors is more accurate to calculate the margin from six directions.