磁共振弥散加权成像及表观弥散系数在鼻咽癌颅底放疗中的应用价值

The application value of magnetic resonance diffusionweighted imaging and apparent diffusion coefficient in skull base radiotherapy for nasopharyngeal carcinoma

目的 磁共振成像(MRI)的弥散加权成像(DWI)技术与表观弥散系数(ADC)在鼻咽癌(NPC)颅底放疗中的应用价值。方法 回顾性分析2017年1月至2020年1月于本院接受颅底放射治疗的103例NPC患者的临床资料,根据患者靶区勾画方式的不同分为MRI组(n=52)与CT组(n=51),MRI组与CT组患者分别利用常规CT技术与MRI的DWI、ADC技术刻画靶区,并根据对应靶区进行颅底放疗。比较两组平均靶区体积、均质性指数(HI)、适形度指数(CI)及正常组织照射剂量。结果 MRI组平均靶区体积、HI、CI值均小于CT组,差异有统计学意义(P<0.05);两组左右眼球、左视神经、脊髓、视交叉照射剂量比较差异无统计学意义,MRI组右视神经、脑干照射剂量均小于CT组,差异有统计学意义(P<0.05)。结论 利用MRI的DWI、ADC技术可提高NPC患者颅底放疗靶区剂量均质性与适形度,减少正常组织照射剂量与不必要照射体积。

Objective To evaluate the value of diffusion weighted imaging(DWI) and apparent diffusion coefficient(ADC) of magnetic resonance imaging(MRI) in skull base radiotherapy of nasopharyngeal carcinoma(NPC). Methods The clinical data of 103 NPC patients who received skull base radiotherapy in our hospital from January2017 to January 2020 were retrospectively analyzed. The patients were divided into MRI group(n=52) and CT group(n=51) according to the different ways of drawing the target area. The patients in MRI group and CT group used conventional CT technology and MRI DWI and ADC technology to depict the target area, and received skull base radiotherapy according to the corresponding target area. The average target volume, homogeneity index(HI), conformal index(CI) and normal tissue irradiation dose were compared between the two groups. Results The average target volume, HI and CI in MRI group were less than those in CT group, and the difference was statistically significant(P<0.05);there was no significant difference in the dose of left and right eyeballs, left optic nerve, spinal cord and optic cross irradiation between the two groups. The dose of right optic nerve and brain stem irradiation in MRI group was less than that in CT group, and the difference was statistically significant(P<0.05). Conclusion DWI and ADC techniques of MRI can improve the dose uniformity and conformability of the target area of skull base radiotherapy in NPC patients, and reduce the radiation dose and unnecessary radiation volume of normal tissues.