Department of Diagnostic Radiology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
Department of Radiology, Research Hospital, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
Eur Radiol. 2022 Jan;32(1):163-173. doi: 10.1007/s00330-021-08105-3. Epub 2021 Jun 16.
To evaluate the effect of emphysema on tumor diameter measured on preoperative computed tomography (CT) images versus pathological specimens.
We investigated patients who underwent primary lung cancer surgery: 55 patients (57 tumors) with severe emphysema and 57 patients (57 tumors) without emphysema. The tumor diameters measured in the postoperative pathological specimens were compared with those measured on the axial CT images and on multiplanar reconstruction (MPR) CT images by two independent radiologists; a subgroup analysis according to tumor size was also performed. A paired or unpaired t test was performed, depending on the tested subjects.
In the emphysema group, the mean axial CT diameter was significantly smaller than the mean pathological diameter (p = 0.025/0.001 for reader 1/2), whereas in the non-emphysema group, the mean axial CT diameter was not significantly different from the pathological one for both readers. The difference between CT axial diameter and pathological diameter (= CT diameter - pathological diameter) was significantly smaller (i.e., had a stronger tendency toward underestimation on radiological measurements) in the emphysema group compared with the non-emphysema group (p = 0.014/0.008 for reader 1/2), and the difference was significantly smaller in tumors sized > 30 mm than tumors sized ≤ 20 mm in both groups.
Tumor size is significantly smaller on preoperative CT in patients with severe emphysema compared to patients without emphysema, especially in the case of large tumors. MPR measurement using the widest of three dimensions should be used to select T-stage for patients with severe emphysema.
• The presence of emphysema affects the accuracy of tumor size measurements on CT. • Compared to patients without emphysema, the tumor size in severe emphysema patients tends to be measured smaller in preoperative CT than the pathological specimen. • This trend is more evident when large tumors are measured on axial CT images alone.
评估术前 CT 图像上肺气肿对肿瘤直径测量的影响与病理标本的相关性。
我们对接受原发性肺癌手术的患者进行了研究：55 例（57 个肿瘤）严重肺气肿患者和 57 例（57 个肿瘤）无肺气肿患者。由两位独立的放射科医生比较术后病理标本上测量的肿瘤直径与轴向 CT 图像和多平面重建（MPR）CT 图像上测量的肿瘤直径；根据肿瘤大小进行了亚组分析。根据测试对象，采用配对或非配对 t 检验。
在肺气肿组中，轴向 CT 平均直径明显小于平均病理直径（读者 1/2 分别为 p = 0.025/0.001），而在非肺气肿组中，两位读者的轴向 CT 平均直径与病理直径均无显著差异。肺气肿组 CT 轴直径与病理直径的差值（即影像学测量的低估程度）明显小于非肺气肿组（读者 1/2 分别为 p = 0.014/0.008），且在两组中，直径大于 30mm 的肿瘤比直径小于等于 20mm 的肿瘤差值更小。
与无肺气肿患者相比，严重肺气肿患者术前 CT 上肿瘤的大小明显较小，尤其是在大肿瘤的情况下。对于严重肺气肿患者，应使用三个维度中最宽的 MPR 测量值来选择 T 分期。
• 肺气肿的存在会影响 CT 上肿瘤大小测量的准确性。• 与无肺气肿患者相比，在严重肺气肿患者中，术前 CT 上的肿瘤大小比病理标本上的肿瘤测量值更小。• 当单独使用轴向 CT 图像测量大肿瘤时，这种趋势更为明显。
