Zhang Bo-Wei, Zhang Yu, Ye Jian-Ding, Qiang Jin-Wei
Department of Radiology, Jinshan Hospital & Shanghai Medical College, Fudan University, Shanghai, China.
Department of Radiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.
Quant Imaging Med Surg. 2021 Jan;11(1):204-214. doi: 10.21037/qims-19-998.
Lung cancer is a major cause of death, and adenocarcinoma is the most common histologic subtype. Precise diagnosis and treatment of invasive adenocarcinoma (IAC) can substantially improve the survival of patients. However, early-stage adenocarcinomas frequently appear as subsolid nodules (SSN) on computed tomography (CT), and the optimal cut-off CT value for differentiating the invasiveness of SSNs in emphysematous patients is unclear.
High-resolution CT targeted scans of 187 pulmonary SSNs in 175 patients with emphysema as confirmed by surgery and histology were retrospectively reviewed. The mean CT value, the relative CT (rCT) values of 1 (nodule CT value - lung CT value), and 2 (nodule CT value/lung CT value), and the size of the SSNs were measured and calculated. The differentiating performance of the CT values between pre-invasive and invasive tumors was evaluated using a receiver operating characteristic (ROC) curve.
Significant differences were found in the rCT values of 1 and 2 among pure ground-glass nodules (GGNs) with different levels of invasiveness, in the rCT values of 1 and 2 for the ground-glass component (GGC) and the mean CT value of the solid component (SC) of part-solid nodules (PSNs) between minimally invasive adenocarcinoma (MIA) and IAC (all P<<0.05). The size was significantly different among pure GGNs with different invasiveness (P<0.05). The cut-off rCT values of 1, 2 and nodule size for differentiating between pre-invasive and invasive pure GGNs were 293.82 [sensitivity 58.0%, specificity 94.7%; area under the curve (AUC) 0.783], 0.68 (sensitivity 89.5%, specificity 58.0%, AUC 0.742) and 1.10 cm (sensitivity 74.0%, specificity 79.0%, AUC 0.796), respectively. The AUCs of combining rCT values 1 and 2 with the size of nodule were 0.795 (sensitivity 62.5%, specificity 89.5%) and 0.845 (sensitivity 71.6%, specificity 89.5%) respectively. There were no significant differences in the mean CT values between pure GGNs with different levels of invasiveness and between the GGC of PSNs of MIA and IAC.
In patients with emphysema, the rCT values are more useful than the mean CT values for differentiating between SSNs with different invasiveness and can be valuable for patient management.
肺癌是主要的死亡原因，腺癌是最常见的组织学亚型。侵袭性腺癌（IAC）的精确诊断和治疗可显著提高患者生存率。然而，早期腺癌在计算机断层扫描（CT）上常表现为亚实性结节（SSN），对于区分肺气肿患者SSN侵袭性的最佳CT阈值尚不清楚。
回顾性分析175例经手术和组织学证实为肺气肿患者的187个肺部SSN的高分辨率CT靶向扫描结果。测量并计算平均CT值、相对CT（rCT）值[1（结节CT值-肺CT值）和2（结节CT值/肺CT值）]以及SSN的大小。采用受试者工作特征（ROC）曲线评估CT值在浸润前和浸润性肿瘤之间的鉴别性能。
不同侵袭程度的纯磨玻璃结节（GGN）之间的rCT值1和2、微浸润腺癌（MIA）与IAC之间部分实性结节（PSN）的磨玻璃成分（GGC）的rCT值1和2以及实性成分（SC）的平均CT值存在显著差异（均P<<0.05）。不同侵袭程度的纯GGN之间大小有显著差异（P<0.05）。区分浸润前和浸润性纯GGN的rCT值1、2及结节大小的截断值分别为293.82[灵敏度58.0%，特异度94.7%；曲线下面积（AUC）0.783]、0.68（灵敏度89.5%，特异度58.0%，AUC 0.742）和1.10 cm（灵敏度74.0%，特异度79.0%，AUC 0.796）。rCT值1和2与结节大小联合的AUC分别为0.795（灵敏度62.5%，特异度89.5%）和0.845（灵敏度71.6%，特异度89.5%）。不同侵袭程度的纯GGN之间以及MIA与IAC的PSN的GGC之间的平均CT值无显著差异。
在肺气肿患者中，rCT值在区分不同侵袭性的SSN方面比平均CT值更有用，对患者管理有重要价值。
