倒U型负压真空垫联合热塑膜固定技术在直肠癌放疗中的临床应用

Clinical Application of Inverted U-shaped Vacuum Pad Combined with Thermoplastic Film Fixation in Rectal Cancer Radiothera

目的:探讨倒U型负压真空垫联合热塑膜固定技术在直肠癌放疗过程中的临床应用价值及误差分析。方法:回顾性分析2017年1月—2022年10月在新乡医学院第一附属医院进行放疗的48例直肠癌患者的临床资料,按倒U型负压真空垫联合热塑膜固定和常规热塑膜固定两种方法进行分组,每组各24例。观察组患者选择倒U型负压真空垫联合热塑膜固定,采用俯卧位;对照组患者选择常规热塑膜固定,采取仰卧位。应用放疗计划系统比较两组患者计划靶区,对危及器官膀胱、小肠、股骨头、脊髓剂量学进行分析,比较两组患者的摆位误差及随诊复发率。结果:两组患者靶区的Dmean、D95、照射体积、均匀性指数(HI)、适形性指数(CI)及危及器官的脊髓与股骨头的剂量比较,差异无统计学意义(t=0.167、0.967、1.196、1.169、0.411,P>0.05);观察组小肠、膀胱的接受照射体积、Dmean、V40明显低于对照组,差异有统计学意义(t=-5.387、-10.910、-19.850、-23.140、-17.730、-18.220,P<0.05);观察组Y轴(头—脚)的摆位误差明显小于对照组,差异有统计学意义(t=-8.634,P<0.05);对两组患者术后1、2、3年进行随访,复发率比较,差异无统计学意义(χ^(2)=1.021、0.167、0.137,P>0.05)。结论:在直肠癌的放疗过程中,倒U型负压真空垫联合热塑膜固定技术能保证放疗疗效,还可降低小肠、膀胱的受量,同时能减小Y轴(头—脚)方向摆位误差。

Objective:To explore the clinical application value and error analysis of inverted U-shaped vacuum pad combined with thermoplastic film fixation technology in rectal cancer radiotherapy.Methods:48 patients with rectal cancer after operation were randomly divided into two groups.The patients in the observation group were fixed with inverted U-shaped negative pressure vacuum pad and thermoplastic film,while the patients in the control group were fixed with conventional thermoplastic film.Radiotherapy planning system was used to compare the dosimetric analysis of planned target area and endangered organs of bladder,small intestine,femoral head and spinal cord between the two groups.Comparison of placement error and follow-up recurrence rate between the two groups were conducted.Results:There was no significant difference in Dmean,D95,irradiation volume,homogeneity index(HI),conformal index(CI)of PTV between the two groups,as well as the dose of spinal cord and femoral head endangering organs(t=0.167,0.967,1.196,1.169,0.411;P>0.05).The irradiation volume,Dmean and V40 of small intestine and bladder in the observation group were significantly lower than those in the control group(t=-5.387,-10.910,-19.850,-23.140,-17.730,-18.220;P<0.05).The placement error of Y-axis(head-foot)in the observation group was significantly smaller than that in the control group,with statistically significant difference(t=-8.634,P<0.05).There was no statistically significant difference between the two groups in the recurrence rate of patients in 1,2 and 3 years of follow-up(χ^(2)=1.021,0.167,0.137;P>0.05).Conclusion:In the process of radiotherapy for rectal cancer,the inverted U-shaped negative pressure vacuum pad combined with thermoplastic film fixation technology can ensure the radiotherapy effect,reduce the amount of small intestine and bladder,and reduce the positioning error in the Y axis(head foot)direction.