Cruz-Hernández Eddiel, Mahmood Usman, Golia Pernicka Jennifer S, Paroder Viktoriya, Petkovska Iva, Gollub Marc J, Shia Jinru, Ganesh Karuna, Bates David D B
Ponce Health Sciences University, Ponce, Puerto Rico.
Department of Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Quant Imaging Med Surg. 2021 May;11(5):2085-2092. doi: 10.21037/qims-20-917.
To evaluate quantitative iodine parameters from the arterial phase dual-energy computed tomography (DECT) scans as an imaging biomarker for tumor grade (TG), mitotic index (MI), and Ki-67 proliferation index of hepatic metastases from neuroendocrine tumors (NETs) of the gastrointestinal (GI) tract. Imaging biomarkers have the potential to provide relevant clinical information about pathologic processes beyond lesion morphology. NETs are a group of rare, heterogeneous neoplasms classified by World Health Organization (WHO) TG, which is derived from MI and Ki-67 proliferation index. Imaging biomarkers for these pathologic features and TG may be useful.
Between January 2014 and April 2019, 73 unique patients with hepatic metastases from NET of the GI tract underwent DECT of the abdomen with an arterial phase were analyzed after exclusions. Using GSIViewer software (GE Healthcare, Madison, Wisconsin), elliptical regions of interest (ROIs) were placed over selected hepatic metastases by a fellowship trained abdominal radiologist. Quantitative iodine concentration (IC) data was extracted from the lesion ROIs, and the normalized IC (lesion IC/aorta IC) and relative IC (lesion IC/liver IC) for each liver were calculated. Spearman correlation was calculated for lesion mean IC, normalized IC, and relative IC to both Ki-67 proliferation and mitotic indices. Student's t-test was performed to compare lesion mean IC, normalized IC and relative IC between WHO TGs.
There was very weak correlation between both normalized IC and relative IC for both Ki-67 proliferation and mitotic indices. A significant difference was not observed between normalized IC and relative IC to distinguish metastases from G1 and G2/3 tumors.
Our study finds limited potential for quantitative parameters from DECT to distinguish neuroendocrine hepatic metastases by WHO TG, as well as limited potential as an imaging biomarker for Ki-67 proliferation and mitotic indices in this setting. Our findings of a lack of correlation between Ki-67 and quantitative iodine parameters stands in contrast to existing literature that reports positive correlations for these parameters in the rectum and stomach.
评估动脉期双能计算机断层扫描（DECT）图像中的定量碘参数，将其作为胃肠道神经内分泌肿瘤（NETs）肝转移瘤的肿瘤分级（TG）、有丝分裂指数（MI）和Ki-67增殖指数的成像生物标志物。成像生物标志物有可能提供有关病变形态以外病理过程的相关临床信息。NETs是一组罕见的异质性肿瘤，由世界卫生组织（WHO）根据TG进行分类，TG源自MI和Ki-67增殖指数。针对这些病理特征和TG的成像生物标志物可能会有所帮助。
2014年1月至2019年4月期间，对73例胃肠道NETs肝转移的独特患者进行了腹部动脉期DECT检查，排除后进行分析。由接受过专项培训的腹部放射科医生使用GSIViewer软件（通用电气医疗集团，威斯康星州麦迪逊），在选定的肝转移瘤上放置椭圆形感兴趣区（ROIs）。从病变ROIs中提取定量碘浓度（IC）数据，并计算每个肝脏的标准化IC（病变IC/主动脉IC）和相对IC（病变IC/肝脏IC）。计算病变平均IC、标准化IC和相对IC与Ki-67增殖指数和有丝分裂指数的Spearman相关性。采用学生t检验比较WHO各TG组之间的病变平均IC、标准化IC和相对IC。
标准化IC和相对IC与Ki-67增殖指数和有丝分裂指数之间的相关性都非常弱。在区分G1和G2/3肿瘤转移方面，标准化IC和相对IC之间未观察到显著差异。
我们的研究发现，DECT的定量参数在通过WHO TG区分神经内分泌肝转移瘤方面潜力有限，在此情况下作为Ki-67增殖和有丝分裂指数的成像生物标志物的潜力也有限。我们发现Ki-67与定量碘参数之间缺乏相关性，这与现有文献报道的这些参数在直肠和胃中呈正相关形成对比。
