头颈部肿瘤螺旋断层调强放疗行或不行图像引导靶区和危及器官的照射剂量比较

目的:评价图像引导在头颈部肿瘤患者调强放疗过程中的作用。方法:12例头颈部肿瘤患者运用TomoTherapy系统治疗，计算患者行或不行图像引导情况下靶区和危及器官照射剂量，分析剂量差异。结果:头颈部肿瘤患者实施螺旋断层放疗，治疗前不行图像引导，脊髓最大剂量较行图像引导的情况下升高约1.09%，GTV、PTV D95、D98有所降低，降低的幅度分别GTV:1.79%、2.19%，PTV:2.37%、2.15%。行或不行图像引导，GTV、PTV D2、下颌骨剂量、双侧腮腺剂量无明显差异。结论:头颈部肿瘤患者放疗时行或不行图像引导，靶区和危及器官照射剂量存在差异，但差异很小，不必每次放疗前行图像引导。对于脊髓受量接近最大剂量限制阈值，建议每次放疗前进行图像引导。

Comparison of radiation dose in target and OAR with IGRT and non-IGRT approach for head and neck cancers treated with TomoTherapy

Objective:To study the value of IGRT in head and neck cancers with TomoTherapy system.Methods:Twelve patients with head and neck cancers were treated with TomoTherapy,calculate the radiation dose of the target and the OAR with IGRT and non-IGRT approach,aiming to analyze the dose difference.Results:Compared with the IGRT,GTV's D95,D98 reduced by 1.79%,2.19%(P=0.04,0.02),respectively;PTV's D95,D98 decreased by 2.37%,2.15%(P=0.02,0.00),respectively in non-IGRT;the Dmax of spinal cord increased by 1.09% than the IGRT (P=0.03).There was no statistically significant difference between the two scenarios (GTV's,PTV's D2,Dmax,Dmean of mandible and parotid gland).Conclusion:In the analyzed group,the radiation dose to the targets and the OAR does not differ significantly between an IGRT and a non-IGRT approach.For patients treated with dose close to the tolerance dose of the spinal cord,we recommend daily IGRT.