头颈部肿瘤螺旋断层放疗颈部剂量优化的研究

Neck Dose Optimization Study of Spiral Tomotherapy for Head and Neck Tumors

目的探讨头颈部肿瘤螺旋断层放疗中降低颈部照射剂量的可行性研究。方法选取20例对头颈部肿瘤实施螺旋断层放射治疗计划的患者,采用两种不同的优化方法设计放疗计划:正常组:靶区与危及器官(包括脊髓与两侧腮腺)采用常用方式进行剂量优化;优化组:在正常组优化基础上增加一个颈部的剂量限制参数,对皮肤进行优化。通过参数比较两组优化方法的剂量学与机器跳数差异。结果两组计划靶区的剂量参数比较无明显差异,危及器官差异无统计学意义,但优化组的皮肤剂量的V10、V20、V30、V40以及V50明显降低,且优化组的机器跳数(Mu)也明显减少。结论在头颈部肿瘤螺旋断层放疗中,对颈部剂量设置参数限制的优化方式,可以明显降低颈部的剂量,提高治疗效率。

Objective To explore the feasibility study of reducing neck radiation dose in spiral tomotherapy of head and neck tumors.Methods The paper chose 20 of cases head and neck tumor patients with spiral tomographic radiotherapy scheme,and designed radiotherapy plans with two different optimization methods,normal group:dose of target areas and risky organs(including spinal cord and parotid glands)were optimized in common ways;optimized group:on the basis of normal groups,added neck dose limiting parameter for skin optimization.Difference in dosimetry and machine hops of two optimization methods were compared by parameters.Results There was no significant difference in dose parameters of planned target areas between two groups,the dose parameters of risky organs were not statistically different.However,skin doses of optimized group V10,V20,V30,V40 and V50 were significantly reduced,and machine hops numbers of optimized group(Mu)were significantly reduced.Conclusion In spiral tomographic radiotherapy of head and neck tumors,optimization method of setting parameter limits for neck dose can reduce neck dose and improve treatment effect significantly.