鼻咽癌患者计划靶区六维与三维误差校正的比较

文献信息

中文摘要

引言： 在放射治疗过程中，患者可能会出现定位误差，这会影响照射体积并导致正常组织接受不必要的辐射剂量。对于接受放射治疗的患者，校正摆位误差至关重要；然而，在鼻咽癌中，六维（6D）校正是否优于传统三维（3D）校正仍不清楚。因此，本研究的目的是比较鼻咽癌患者三维与六维锥形束计算机断层扫描（CBCT）校正之间的计划靶区（PTV）覆盖情况。
方法： 我们回顾性纳入了30例接受图像引导放射治疗的鼻咽癌患者。分别在1、3和5周时，基于骨骼结构将CBCT图像与CT模拟图像配准后进行3D和6D校正。在3D和6D校正后，计算达到处方剂量70、63和56 Gy的PTV体积百分比，并使用重复测量方差分析进行统计学比较。
结果： 结果显示，3D和6D校正后，靶区体积覆盖率分别为：70 Gy时为94.1%±4.3%和95.4%±3.4%，63 Gy时为94.4%±2.6%和95.3%±2.4%，56 Gy时为92.1%±7.7%和95.6%±5.4%。两种校正方法在56 Gy时的体积覆盖方面存在显著差异。此外，3D和6D校正后，脊髓的平均最大剂量百分比分别为5.9%±8.0%和3.3%±6.2%，脑干分别为1.8%±8.5%和2.7%±6.0%；然而，两种校正方法之间未观察到显著差异。
结论： 我们得出结论，在鼻咽癌患者中，CBCT图像的6D校正比3D校正实现了更好的靶肿瘤体积剂量覆盖。

英文摘要

INTRODUCTION: During radiation therapy, patients may experience positioning errors that can affect the irradiated volume and result in unnecessary radiation doses to normal tissues. Correcting for setup errors is essential for patients undergoing radiation therapy; however, it remains unclear whether six-dimensional (6D) correction is superior to conventional three-dimensional (3D) correction in nasopharyngeal cancer. Therefore, the purpose of this study was to compare the planning target volume (PTV) coverage between 3D and 6D cone-beam computed tomography (CBCT) corrections for patients with nasopharyngeal carcinoma.
METHODS: We retrospectively enrolled 30 patients with nasopharyngeal cancer who underwent image-guided radiation therapy. The 3D and 6D corrections were performed using CBCT images registered to CT simulation images based on skeletal structures at 1, 3, and 5 weeks, respectively. The volume percentages of the PTV achieving the prescribed dose of 70, 63, and 56 Gy were calculated after both 3D and 6D corrections and were statistically compared using a repeated measures analysis of variance test.
RESULTS: The results showed that the percentage coverage of the target volume was 94.1% ± 4.3% and 95.4% ± 3.4% for 70 Gy, 94.4% ± 2.6% and 95.3% ± 2.4% for 63 Gy, and 92.1% ± 7.7% and 95.6% ± 5.4% for 56 Gy after 3D and 6D corrections, respectively. A significant difference was noted in the volume coverage for 56 Gy between the two correction methods. Additionally, the average maximum dose percentages after 3D and 6D corrections were 5.9% ± 8.0% and 3.3% ± 6.2% for the spinal cord, and 1.8% ± 8.5% and 2.7% ± 6.0% for the brain stem, respectively; however, no significant difference was observed between the two correction methods.
CONCLUSION: We conclude that 6D correction for CBCT images achieved better dose coverage of the target tumour volume than 3D correction in patients with nasopharyngeal carcinoma.