鼻咽癌乏氧区MRI影像组学特征分析

Analysis of MRI radiomic features of hypoxic area in nasopharyngeal carcinoma patients

目的分析鼻咽癌乏氧区MR图像中影像组学特征,为乏氧区识别和分析提供参考.方法回顾分析32例初诊鼻咽癌患者18F-FMISO-PET图像和短期内获得的MRI T1、T2、T1+图像.在MR图像勾画GTV,以4 h的PET图像为依据勾画乏氧区域(GTV-H),将GTV减乏氧区定义为非乏氧区(GTV-NH).提取GTV-H与GTV-NH影像组学特征,比较二者影像组学特征在不同MRI序列图像中差异.结果GTV-H平均值为(10.92±11.02)cm3,GTV-NH平均值为(7.21±5.70)cm3.GTV-H与GTV-NH在MRI-T1中的灰度强度中全域最小值(ID-GM)获得的最大变化率为46%(P<0.05、AUC>0.7、约登系数>0.5);在MRI-T2中的灰度游程矩阵长游程因子(LRE)、长游程高灰度因子(LRHGLE)、长游程低灰度因子(LRLGLE)平均变化率达136%(P<0.05、AUC>0.7、约登系数>0.5);在MRI-T1+中的ID-GM、LRE、LRHGLE、HRLGLE变化率>90%(P<0.05、AUC>0.7、约登系数>0.5).结论MRI部分影像组学特征可客观反映鼻咽癌肿瘤靶区乏氧区域,量化和追踪这些特征变化有利于对鼻咽癌乏氧区域的识别.

Objective To analyze the magnetic resonance imaging(MRI)radiomic performance of hypoxic area in nasopharyngeal carcinoma patients,aiming to provide a reference for identification and analysis of hypoxic area.Methods The MRI-T1,MRI-T2,MRI-T1+and PET/CT images of 32 patients initially diagnosed with nasopharyngeal carcinoma were retrospectively analyzed.The gross tumor volume(GTV)of nasopharynx was countoured and the hypoxic areas(GTV-H)were identified by 18F-FMISO-PET images.The non-hypoxic areas(GTV-NH)were defined as the rest of areas removed GTV-H from GTV.The radiomic features of GTV-H and GTV-NH were extracted and compared.Results The average volume of GTV-H and GTV-NH was(10.92±11.02)cm3 and(7.21±5.70)cm3,respectively.The maximum rate of change was 46%for intensity direct-global min(ID-GM)on MRI-T1(P<0.05,AUC>0.7 and Youden index>0.5).The average rate of change was 136%for long run emphasis(LRE),long run high gray level emphasis(LRHGLE)and long run low gray level emphasis(LRLGLE)on MRI-T2(P<0.05,AUC>0.7 and Youden index>0.5).The high change rates was greater than 90%on MRI-T1+(P<0.05,AUC>0.7 and Youden index>0.5)for ID-GM,LRE,LRHGLE and LRLGLE.Conclusions The hypoxic area of tumor target can be reflected by MRI radiomics on T1/T2/T1+.Quantifying and tracking the variations of these features can bring benefit to recognize the hypoxic area of nasopharyngeal carcinoma tumor target.