| 局部晚期食管鳞癌放疗的实际剂量分布误差追踪评价 |
| |
| 引用本文： | 刘懿梅,,彭应林,邱波,李绮雯,张俊,刘慧,邓小武,吴德华.局部晚期食管鳞癌放疗的实际剂量分布误差追踪评价[J].中国医学物理学杂志,2021,0(12):1453-1459. |
| |
| 作者姓名： | 刘懿梅 彭应林 邱波 李绮雯 张俊 刘慧 邓小武 吴德华 |
| |
| 作者单位： | 1.南方医科大学南方医院放疗科， 广东 广州 510515； 2.中山大学肿瘤防治中心/华南肿瘤学国家重点实验室/肿瘤医学协同创新中心， 广东 广州 510060 |
| |
| 摘 要： | 【摘要】目的:通过重复扫描模拟CT图像评估局部晚期食管鳞癌放疗过程中因摆位误差、呼吸运动和解剖结构位移等引起的靶区和危及器官剂量变化，探讨食管癌自适应放疗的需求。方法:共入组行放疗的局部晚期食管鳞癌患者13例，其中7例接受调强放疗，6例接受三维适形放疗，处方剂量均为PTV1:64 Gy/32 F，PTV2:46 Gy/23 F。第5、10、15、20、25次治疗结束后，对患者重新行模拟CT扫描并勾画靶区和危及器官，计算治疗计划在重复CT图像上的剂量分布。通过形变配准方法对治疗剂量进行追踪累加，得到治疗的实际累积剂量分布，并与原始计划进行剂量学比较。结果:PTV1和PTV2的处方剂量覆盖率随着放疗的进行均有不同程度的下降，双肺Dmean和脊髓D1 cc均有明显增加。至治疗结束时，PTV1 和PTV2的V95%平均下降了-2.73%±2.82%和-1.88%±1.44%（P<0.05）。其中有2例PTV1的V95%下降超过-5%，最大偏差达到-9.16%。双肺Dmean和脊髓D1 cc实际受照剂量分别从（17.90±2.78） Gy和（47.04±3.21） Gy增加至（18.27±3.18） Gy和（49.02±3.96） Gy，分别增加了1.84%±3.83%和4.25%±5.72%，其中脊髓D1 cc的变化具有统计学意义（P<0.05），脊髓D1 cc发生偏差大于3%和5%的病例数分别为6例和5例。心脏Dmean变化不明显。结论:在局部晚期食管鳞癌患者放疗过程中，计划靶区的处方剂量覆盖率有所降低，超50%病例的肺和脊髓受照剂量增加，疗程中的剂量评估和在第10次治疗后实施自适应放疗可能会有临床获益。
|
| 关 键 词： | 局部晚期食管鳞癌 自适应放疗 靶区覆盖率 剂量偏差比 |
Tracking and evaluation of actual dose distribution errors in radiotherapy for locally advanced esophageal squamous cell carcinoma |
| |
| LIU Yimei,,PENG Yinglin,QIU Bo,LI Qiwen,ZHANG Jun,LIU Hui,DENG Xiaowu,WU Dehua.Tracking and evaluation of actual dose distribution errors in radiotherapy for locally advanced esophageal squamous cell carcinoma[J].Chinese Journal of Medical Physics,2021,0(12):1453-1459. |
| |
| Authors: | LIU Yimei PENG Yinglin QIU Bo LI Qiwen ZHANG Jun LIU Hui DENG Xiaowu WU Dehua |
| |
| Affiliation: | 1. Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China 2. Sun Yat-sen University Cancer Center/State Key Laboratory of Oncology in South China/Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China |
| |
| Abstract: | Abstract: Objective To evaluate dosimetric changes of target areas and organs-at-risk caused by positioning error, respiratory movement and anatomical structure displacement during radiotherapy for locally advanced esophageal squamous cell carcinoma using simulated CT images obtained by repeated scanning, and to explore the demands of adaptive radiotherapy for esophageal cancer. Methods Thirteen patients with locally advanced esophageal squamous cell carcinoma were enrolled, including 7 treated with intensity-modulated radiotherapy and 6 receiving three-dimensional conformal radiotherapy. The prescribed doses to PTV1 and PTV2 were 64 Gy/32 F and 46 Gy/23F, respectively. Simulated CT scanning was repeated at the end of the 5th, 10th, 15th, 20th and 25th treatments, and the target area and organs-at-risk were delineated, and the dose profile of treatment plan was calculated in the repeated CT image. The treated dose (Dtreated) was tracked and accumulated by deformation registration method for obtaining the actual accumulated dose profile which was then compared with that in the original plan (Dplanned). Results Along with radiotherapy, the prescribed dose coverage rates of PTV1 and PTV2 were decreased accordingly, while the Dmean to lungs and the D1cc to spinal cord were increased significantly. At the end of treatment, the V95% of PTV1 and PTV2 were decreased by -2.73%±2.82% and -1.88%±1.44%, respectively (P<0.05). There were 2 cases in which the V95% of PTV1 had a decrease more than 5%, with a maximum deviation of -9.16%. The Dmean to lungs and the D1 cc to spinal cord in treatment practice were increased from (17.90±2.78) Gy and (47.04±3.21) Gy to (18.27±3.18) Gy and (49.02±3.96) Gy, respectively, increasing by 1.84%±3.83% and 4.25%±5.72%, respectively, and the difference in the D1 cc to spinal cord was statistically significant (P<0.05). The number of cases with spinal cord D1 cc deviations greater than 3% and 5% was 6 and 5, respectively. The change in the Dmean to the heart was trivial. Conclusion During radiotherapy for locally advanced esophageal squamous cell carcinoma, the prescribed dose coverage rate of target area is decreased, and the radiation doses to lungs and spinal cord are increased in more than 50% cases. Dose evaluation during the course of treatment and the implementation of adaptive radiotherapy at the end of the 10th treatment may have clinical benefits. |
| |
| Keywords: | Keywords: locally advanced esophageal squamous cell carcinoma adaptive radiotherapy target coverage dose deviation ratio |
|
| 点击此处可从《中国医学物理学杂志》浏览原始摘要信息 |
|
点击此处可从《中国医学物理学杂志》下载全文 |
|
