中晚期宫颈癌图像引导放射治疗的剂量学研究

Dosimetric Study of Image-Guided Radiotherapy for Advanced Cervical Cancer

摘要: 目的：探讨中晚期宫颈癌5野、7野、9野3种图像引导放射治疗计划的靶区和危及器官的剂量学差异。方法：选取本院47例局部晚期宫颈癌患者，经定位、CT扫描及靶区勾画后，分别设计5野、7野、9野IGRT计划。分析靶区的剂量学参数、均匀性和适形性指数，以及危及器官的剂量学参数。结果：5野计划中PTV的HI和CI明显劣于7野和9野，5野计划中直肠的V₃₀、V₄₀，膀胱的V₂₀、V₄₀，左侧股骨头的V₄₀、V₅₀和右侧股骨头的V₃₀、V₄₀、V₅₀明显高于7野和9野计划，差异均有统计学意义。而7野和9野计划间靶区和危及器官剂量参数相近，差异无明显统计学意义。结论：在权衡靶区和危及器官的剂量学参数要求方面，7野图像引导放射治疗计划可以作为中晚期宫颈癌临床首选的治疗计划。

Abstract: Objective: To compare the dosimetric differences of target areas and organs at risk among three image-guided radiotherapy plans for advanced cervical cancer. Methods: Forty-seven patients with advanced cervical cancer in our hospital were selected. 5-field, 7-field and 9-field IGRT plans were designed after localization, CT scan and target area delineation. The dose parameters, uniformity and conformity index of target area, and dosimetric parameters of organs at risk were analyzed. Results: The HI and CI of PTV in 5-field plan were significantly inferior to those in 7-field and 9-field plans. Moreover, the V₃₀, V₄₀ of rectum, V₂₀ and V₄₀ of bladder, V₄₀, V₅₀ of left femoral head and V₃₀, V₄₀ and V₅₀ of right femoral head in 5-field plan were significantly higher than those in 7-field plan and 9-field plan, and the difference was statistically significant. There was no significant difference in target and organ at risk dose parameters between the 7-field and 9-field plans. Conclusion: In terms of weighing the dosimetric parameters of target area and organs at risk, 7-field image-guided radiotherapy plan can be the first choice for the treatment of advanced cervical cancer.