直肠癌化疗前后的 MRI 分期：弥散成像在评估直肠周围浸润中的作用。

Primary and post-chemoradiotherapy staging using MRI in rectal cancer: the role of diffusion imaging in the assessment of perirectal infiltration.

机构信息

Clinical Sciences Department, Faculty of Medicine, University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe, s/n. 35016, Las Palmas de Gran Canaria, Spain.

Department of General Surgery, Complejo Hospitalario Universitario Insular Materno-Infantil, Av. Marítima, s/n. 35016, Las Palmas de Gran Canaria, Spain.

出版信息

Abdom Radiol (NY). 2019 Nov;44(11):3674-3682. doi: 10.1007/s00261-019-02139-4.

DOI:10.1007/s00261-019-02139-4

PMID:31332499

Abstract

PURPOSE

To analyze changes in MRI diagnostic accuracy in main rectal tumor (T) evaluation resulting from the use of diffusion-weighted imaging (DWI), according to the degree of experience of the radiologist.

METHODS

This is a cross-sectional study of a database including one hundred 1.5 T MRI records (2011-2016) from patients with biopsy-proven rectal cancer, including primary staging and post-chemoradiotherapy follow-up. All cases were individually blindedly reviewed by ten radiologists: three experienced in rectal cancer, three specialized in other areas, and four residents. Each case was assessed twice to detect perirectal infiltration: first, evaluating just high-resolution T2-weighted sequences (HRT2w); second, evaluation of DWI plus HRT2w sequences. Results were pooled by experience, calculating accuracy (area under ROC curve), sensitivity and specificity, predictive values, likelihood ratios, and overstaging/understaging. Histology of surgical specimens provided the reference standard.

RESULTS

DWI significantly improved specificity by experienced radiologists in primary staging (63.2% to 75.9%) and, to a lesser extent, positive likelihood ratio (2.06 to 2.87); minimal changes were observed post-chemoradiotherapy, with a slight decrease of accuracy (0.657 to 0.626). Inexperienced radiologists showed a similar pattern, but with slight enhancement post-chemoradiotherapy (accuracy 0.604 to 0.621). Residents experienced small changes, with increased sensitivity/decreased specificity in both primary (69% to 72%/67.2% to 64.7%) and post-chemoradiotherapy (68.1% to 73.6%/47.3% to 44.6%) staging.

CONCLUSIONS

Adding DWI to HRT2w significantly improved specificity for the detection of perirectal infiltration at primary staging by experienced radiologists and also by inexperienced ones, although to a lesser extent. In the post-neoadjuvant treatment subgroup, only minimal changes were observed.

摘要

目的

分析扩散加权成像（DWI）在直肠主肿瘤（T）评估中的应用对磁共振成像（MRI）诊断准确性的影响，根据放射科医生的经验程度进行分析。

方法

这是一项回顾性数据库研究，纳入了 100 例经活检证实的直肠癌患者 1.5 T MRI 记录（2011-2016 年），包括原发分期和放化疗后随访。所有病例均由 10 名放射科医生进行个体盲法复查：3 名具有直肠癌诊治经验，3 名专业领域为其他，4 名为住院医师。每位医生对每个病例进行两次评估，以检测直肠周围浸润：第一次评估仅使用高分辨率 T2 加权序列（HRT2w）；第二次评估使用 DWI 加 HRT2w 序列。根据经验对结果进行汇总，计算准确性（ROC 曲线下面积）、敏感度、特异度、预测值、似然比和过分期/分期不足。手术标本的组织学检查为参考标准。

结果

在原发分期中，DWI 显著提高了有经验放射科医生的特异性（63.2%至 75.9%），阳性似然比也略有升高（2.06 至 2.87）；放化疗后，其特异性有轻微改善，准确性略有下降（0.657 至 0.626）。无经验放射科医生也表现出类似模式，但放化疗后稍有改善（准确性 0.604 至 0.621）。住院医师的变化较小，原发期（69%至 72%/67.2%至 64.7%）和放化疗后（68.1%至 73.6%/47.3%至 44.6%）的敏感性增加，特异性降低。