螺旋断层治疗机实施剂量重建和剂量引导放疗的研究

Clinical Implementation of Dose Reconstruction and Dose-Guided Intensity Modulated Radiotherapy for Helical Tomotherapy

目的通过螺旋断层治疗系统MVCT确定实现实际剂量重建的可行性,并探讨其剂量引导放疗过程。方法利用螺旋断层治疗系统自适应软件,将一例鼻咽癌患者治疗过程中在线MVCT图像实施剂量计算,获得实际剂量与计划剂量的差异范围和程度的分布图,勾画实际超量或欠量区域,在后续分次放疗中对该区域进行剂量调整。结果患者位置移动所导致的实际剂量与计划剂量的差异可以通过ξ分布图直观地反映出来,勾画图中超量或欠量区域,在进行再计划后可对后续分次放疗的剂量分布进行调整,以实现剂量引导放疗。结论螺旋断层治疗机能够成功完成实际分次和累积剂量重建,能用于剂量引导的自适应放疗。

Objective To implement dose reconstruction and dose-guided intensity modulated radiotherapy for helical tomotherapy. Methods Dose reconstruction was implemented on adaptive helical tomotherapy with the online melgavotage CT（MVCT） imaging from a patient with nasopharyngeal cancer. The differences of isodose line between actual and planned deposition were analysised in 3D distribution,on which the hot spot and cold spot were lined. The dose delivered to these areas was modulated in later fractions to keep the planned requirement. Results The differences between actual and planned isodose line were shown on the ~ image visually. The modulation to the hot spot and cold spot in later fraction corrected the incorrectly delivered dose to achieve the requirement of primary plan. Conclutions The dose reconstruction and dose-guided intensity modulated radiotherapy can be implemented in adaptive helical tomotherapy.