胸段食管癌应用调强适形放疗与简化调强适形放疗的剂量学对比

Dosimetric Comparison of Intensity Modulated Conformal Radiotherapy and Simplified Intensity Modulated Conformal Radiotherapy for Thoracic Esophageal Cancer

目的比较胸段食管癌应用调强适形放疗(IMRT)与简化调强适形放疗(sIMRT)的剂量学参数。方法选择该院2018年2—12月收治的胸段食管癌患者80例。所有放疗计划均在Pinnacle治疗计划系统中完成设计,每位患者均设计IMRT和sIMRT两套放疗计划。比较两种计划中靶区剂量参数、危及组织器官剂量参数、机器跳数和子野数目等的差异。结果sIMRT计划的靶区近似最大剂量(D5%)、平均剂量(Dmean)和均匀性指数(HI)均显著小于IMRT计划,而靶区近似最小剂量(D95%)和适形度指数(CI)均显著大于IMRT计划(P<0.05)。两种计划各危及组织器官的剂量学参数比较,差异无统计学意义(P>0.05)。sIMRT计划的机器跳数(423.11±72.40)MU显著少于IMRT计划(498.50±68.92)MU(t=6.746,P<0.05)。结论对于胸段食管癌患者,5野照射的sIMRT计划和IMRT计划的靶区剂量参数均可满足临床要求,IMRT计划具有一定优势,但在危及组织器官的保护方面,两种计划未发现明显差异,因此,在不会给放疗效果带来显著影响的情况下,可优先选择sIMRT计划。

Objective To compare the dosimetric parameters of IMRT and sIMRT for thoracic esophageal cancer.Methods Eighty patients with thoracic esophageal cancer admitted to the hospital from February 2018 to December 2018 were selected.All radiotherapy plans are designed in the Pinnacle treatment planning system,and each patient was designed with two sets of IMRT and sIMRT.Compare the difference in target area dose parameters,endangered tissue and organ dose parameters,machine hops and number of subtields in the two plans.Results The approximate maximum dose(D5%),average dose(Dmean)and uniformity index(HI)of the target area of the sIMRT plan were significantly smaller than those of the IMRT plan,while the approximate minimum dose(D95%)and conformity index(CI)of the target area Both were significantly larger than the IMRT plan(P<0.05).Comparing the dosimetric parameters of the tissues and organs of the two plans,the differences were not statistically significant(P>0.05).The number of machine hops of sIMRT plan(423.11±72.40)MU was significantly less than that of IMRT plan(498.50±68.92)MU(t=6.746,P<0.05).Conclusion For patients with thoracic esophageal cancer,the target dose parameters of the 5-field sIMRT plan and the IMRT plan can meet the clinical requirements.The IMRT plan has certain advantages,but there is no obvious difference between the two plans in terms of protection of tissues and organs.Therefore,the sIMRT plan can be given priority when it does not significantly affect the effectiveness of radiotherapy.