不同全脑全脊髓放射治疗方式剂量学比较及摆位误差的影响

发布时间：2018-06-26 19:29

本文选题：全脑全脊髓照射 + 剂量分布　；参考：《广西医科大学》2013年硕士论文

【摘要】：目的比较不同全脑全脊髓放射治疗(craniospinal irradiation, CSI)方式剂量分布的差异及摆位误差对靶区剂量的影响,以探究最佳的CSI方式。方法在接受过CSI的9例病人图像上分别完成传统二维(传统2D)、通过子野调整剂量分布的二维(子野2D)、三维(3D)、调强(IMRT)及电子线(Electron)的CSI计划,比较不同计划间靶区剂量及危及器官受照剂量。记录患者每周1次的摆位误差值,观察摆位误差造成的靶区剂量差异。分别以6MV-X及15MV-X射线能量完成传统2D及子野2D计划,比较不同射线能量下靶区及危及器官的剂量分布。结果①不同计划方式全脑靶区剂量分布大致相同(P0.05)；②IMRT可以显著降低靶区高量(Vi07%),提高靶区适形度(CI),其次为3D(P0.05)；除Electron外,其余各组在靶区最小剂量(Dmin)、平均剂量(Dmean)、靶区覆盖度(V95%)及剂量均一性(DHI)无显著差异(P0.05)；传统2D靶区最大剂量(Dmax)最高(P0.05)；③Electron靶区Dmin、V95%、DHI、CI均小于其余各组(P0.05)；Electron脊髓深度4.5cm者, V107%、DHI、CI与传统2D、子野2D类似(P0.05)；Dmin、V95%略低(P0.05)；④IMRT与Electron能明显降低正常器官10Gy以上剂量,3D仅次之；Electron具有最小的5Gy剂量体积；⑤引入摆位误差后,子野2D及3D靶区剂量与原计划差别小于其余各组。⑥15MV-X靶区剂量分布略优于6MV-X,同时可降低全身V110%、V120%及V130%；但危及器官接受剂量高于6MV-X(P0.05)。结论综合考虑靶区剂量分布、正常器官保护及摆位误差的影响,可选择3D或IMRT行CSI；对于脊髓深度4.5cm者也可选择电子线照射。6MV-X可靶区达到临床满意的情况下更好地保护危及器官。
[Abstract]:Objective to compare the difference of dose distribution in different whole brain and spinal cord radiotherapy modes and the effect of positioning error on the dose of target area in order to explore the best (craniospinal irradiation, mode. Methods the CSI programs of traditional 2D, 3D, IMRT and Electron were performed on 9 patients with CSI. The dose of target area and organ exposure were compared between different plans. The difference of target dose caused by the error of pendulum was recorded once a week. The conventional 2D and subfield 2D projects were completed with 6MV-X and 15MV-X energy, respectively. The dose distributions of target region and endangered organs were compared under different radiation energies. Results (1) the dose distribution of the whole brain target area in different planning methods was approximately the same (P0.05). IMRT significantly decreased the target area high (Vi07%), increased the target area conformability (CI), followed by 3D (P0.05), except Electron, the dose distribution of the whole brain target area was similar (P0.05). There was no significant difference in minimum dose (Dmin), mean dose (Dmean), coverage (V95%) and dose uniformity (DHI) between the other groups (P0.05), and the highest maximum dose (Dmax) in traditional 2D target (P0.05) was lower than that in other groups (P0.05). In patients with electron spinal cord depth 4.5cm, V107 DHICI was similar to the traditional 2D, and the subfield 2D was similar (P0.05). (P05) Dmin4IMRT and Electron could significantly reduce the dose of normal organs above 10 Gy and the electron had the smallest dose volume of 5 Gy after introducing the pendulum error. The difference of 2D and 3D target dose between subfield and original plan was less than that of other groups. 615MV-X target dose distribution was slightly better than 6MV-X, at the same time, V110V 120% and V130 were decreased, but the acceptance dose of endangerment organs was higher than 6MV-X (P0.05). Conclusion considering the effects of target dose distribution, normal organ protection and pendulum error, 3D or IMRT can be used for CSI. For the patients with deep spinal cord 4.5cm, the electron ray irradiation. 6MV-X could better protect the injured organs if the target area reached clinical satisfaction.
【学位授予单位】：广西医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R730.55

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