Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital Minden, Ruhr University Bochum, Hans-Nolte-Str. 1, Minden 32429, Germany.
Department of Pathology, Johannes Wesling University Hospital Minden, Ruhr University Bochum, Hans-Nolte-Str. 1, Minden 32429, Germany.
Acad Radiol. 2024 Sep;31(9):3620-3626. doi: 10.1016/j.acra.2024.02.006. Epub 2024 Feb 28.
Common computed tomography (CT) investigation plays a limited role in characterizing and assessing the response of rectal cancer (RC) to neoadjuvant radiochemotherapy (NARC). Photon counting computed tomography (PCCT) improves the imaging quality and can provide multiparametric spectral image information including iodine concentration (IC). Our purpose was to analyze associations between IC and histopathology in RC and to evaluate the role of IC in response prediction to NARC.
Overall, 41 patients were included into the study, 14 women and 27 men, mean age, 65.5 years. PCCT in a portal venous phase of the abdomen was performed. In every case, a polygonal region of interest (ROI) was manually drawn on iodine maps. Normalized IC (NIC) was also calculated. Tumor stage, grade, lymphovascular invasion, circumferential resection margin, and tumor markers were analyzed. Tumor regression grade (absence/presence of tumor cells) after NARC was analyzed. NIC values in groups were compared to Mann-Whitney-U tests. Sensitivity, specificity, and area under the curve values were calculated. Intraclass correlation coefficient (ICC) was calculated.
ICC was 0.93, 95%CI= (0.88; 0.96). Tumors with lymphovascular invasion showed higher NIC values in comparison to those without (p = 0.04). Tumors with response grade 2-4 showed higher pretreatment NIC values in comparison to lesions with response grade 0-1 (p = 0.01). A NIC value of 0.36 and higher can predict response grade 2-4 (sensitivity, 73.9%; specificity, 91.7%; area under the curve, 0.85).
NIC values showed an excellent interreader agreement in RC. NIC can predict treatment response to NARC.
常规计算机断层扫描（CT）在直肠肿瘤（RC）的特征描述和评估新辅助放化疗（NARC）的疗效方面作用有限。光子计数 CT（PCCT）可改善成像质量，并提供碘浓度（IC）等多参数光谱图像信息。本研究旨在分析 RC 中 IC 与组织病理学之间的相关性，并评估 IC 在预测 NARC 治疗反应中的作用。
共纳入 41 例患者，包括 14 名女性和 27 名男性，平均年龄为 65.5 岁。所有患者均行腹部门静脉期 PCCT 检查。在每个病例中，手动在碘图上绘制多边形感兴趣区（ROI）。还计算了归一化 IC（NIC）。分析了肿瘤分期、分级、血管淋巴管侵犯、环周切缘和肿瘤标志物。分析了 NARC 后肿瘤的消退分级（有无肿瘤细胞）。采用 Mann-Whitney-U 检验比较各组的 NIC 值。计算了灵敏度、特异性和曲线下面积（AUC）值。计算了组内相关系数（ICC）。
ICC 为 0.93，95%CI=（0.88；0.96）。与无血管淋巴管侵犯的肿瘤相比，有血管淋巴管侵犯的肿瘤的 NIC 值更高（p=0.04）。与消退分级 0-1 的病变相比，消退分级 2-4 的肿瘤的预处理 NIC 值更高（p=0.01）。NIC 值大于 0.36 可以预测消退分级 2-4（灵敏度为 73.9%，特异性为 91.7%，AUC 为 0.85）。
RC 中 NIC 值的观察者间一致性较好。NIC 可预测 NARC 治疗反应。
