PDF(Pubmed)
Abstract：
This study employed a commercial software velocity to perform deformable registration and dose calculation on deformed CT images, aiming to assess the accuracy of dose delivery during the radiotherapy for lung cancers. A total of 20 patients with lung cancer were enrolled in this study. Adaptive CT (ACT) was generated by deformed the planning CT (pCT) to the CBCT of initial radiotherapy fraction, followed by contour propagation and dose recalculation. There was not significant difference between volumes of GTV and CTV calculated from the ACT and pCT. However, significant differences in dice similarity coefficient (DSC) and coverage ratio (CR) between GTV and CTV were observed, with lower values for GTV volumes below 15 cc. The mean differences in dose corresponding to 95% of the GTV, GTV-P, CTV, and CTV-P between ACT and pCT were - 0.32%, 4.52%, 2.17%, and 4.71%, respectively. For the dose corresponding to 99%, the discrepancies were - 0.18%, 8.35%, 1.92%, and 24.96%, respectively. These differences in dose primarily appeared at the edges of the target areas. Notably, a significant enhancement of dose corresponding to 1 cc for spinal cord was observed in ACT, compared with pCT. There was no statistical difference in the mean dose of lungs and heart. In general, for lung cancer patients, anatomical motion may result in both CTV and GTV moving outside the original irradiation region. The dose difference within the original target area was small, but the difference in the planning target area was considerable.
摘要：
本研究采用商业软件速度对变形CT图像进行可变形配准和剂量计算，旨在评估肺癌放疗期间剂量递送的准确性。本研究共纳入20例肺癌患者。通过将计划CT（pCT）变形为初始放疗分数的CBCT来生成自适应CT（ACT）。其次是轮廓传播和剂量重新计算。根据ACT和pCT计算的GTV和CTV的体积之间没有显着差异。然而,GTV和CTV的骰子相似系数(DSC)和覆盖率(CR)存在显著差异,GTV音量低于15cc的值较低。剂量的平均差异对应于95%的GTV，GTV-P,CTV,ACT和pCT之间的CTV-P为-0.32%，4.52%,2.17%，和4.71%，分别。对于对应于99%的剂量，差异为-0.18%，8.35%，1.92%,和24.96%，分别。这些剂量差异主要出现在目标区域的边缘。值得注意的是,在ACT中观察到对应于1cc的脊髓剂量的显着增加，与pCT相比。肺和心脏的平均剂量没有统计学差异。总的来说,对于肺癌患者来说，解剖运动可能导致CTV和GTV移动到原始照射区域之外。原始目标区域内的剂量差异很小，但是规划目标区域的差异很大。
