Background: Recently, the detectable rate of ground-glass opacity (GGO ) was significantly increased, a appropriate diagnosis before clinic treatment tends to be important for patients with GGO lesions. The aim of this study is to validate the ability of the mean computed tomography (m-CT) value to predict tumor invasiveness, and compared with other measurements such as Max CT value, GGO size, solid size of GGO and C/T ratio (consolid/tumor ratio, C/T) to find out the best measurement to predict tumor invasiveness.
Methods: A retrospective study was conducted of 129 patients who recieved lobectomy and were pathological confirmed as atypical adenomatous pyperplasia (AAH) or clinical stage Ia lung cance in our center between January 2012 and December 2013. Of those 129 patients, the number of patients of AAH, AIS, AIS and invasive adenocarcinoma were 43, 26, 17 and 43, respectively. We defined AAH and AIS as noninvasive cancer (NC), MIA and invasive adenocarcinoma were categorized as invasive cancer(IC). We used receiver operating characteristic (ROC) curve analysis to compare the ability to predict tumor invasiveness between m-CT value, consolidation/tumor ratio, tumor size and solid size of tumor. Multiple logistic regression analyses were performed to determine the independent variables for prediction of pathologic more invasive lung cancer.
Results: 129 patients were enrolled in our study (59 male and 70 female), the patients were a median age of (62.0±8.6) years (range, 44 to 82 years). The two groups were similar in terms of age, sex, differentiation (P>0.05). ROC curve analysis was performed to determine the appropriate cutoff value and area under the cure (AUC). The cutoff value of solid tumor size, tumor size, C/T ratio, m-CT value and Max CT value were 9.4 mm, 15.3 mm, 47.5%, -469.0 HU and -35.0 HU, respectively. The AUC of those variate were 0.89, 0.79, 0.82, 0.90, 0.85, respectively. When compared the clinical and radiologic data between two groups, we found the IC group was strongly associated with a high m-CT value, high Max CT value, high C/T ratio and large tumor size. Gender, solid tumor size, tumor size, C/T ratio, m-CT value and MaxCT value were selected factor for multivariate analysis, when using the preoperatively determined variables to predict the tumor invasiveness, revealed that tumor size, C/T ratio, m-CT value and Max CT value were independent predictive factors of IC.
Conclusions: The musurements of Max CT value, GGO size, solid size of GGO and C/T ratio were significantly correlated with tumor invasiveness, and the evaluation of m-CT value is most useful musurement in predicting more invasive lung cancer.
背景与目的 近年来，肺部磨玻璃结节（ground-glass opacity, GGO）的检出率逐年升高，预测GGO的恶性程度对临床治疗至关重要。本研究旨在评价m-CT值（mean computed tomography value, m-CT）在预测早期肺癌和癌前病变恶性程度中的价值，并将m-CT值与MaxCT值（Max computed tomography value, MaxCT）、GGO直径、GGO实性成分直径及C/T比值（consolid/tumor ratio, C/T）对比，得出最佳影像学评价指标。方法 回顾性分析中国科学技术大学附属第一医院胸外科2012年1月-2013年12月接受肺切除手术并有病理证实的肺GGO患者129例，其中非典型腺瘤样增生（atypical adenomatous pyperplasia, AAH）43例、原位腺癌（adenocarcinoma in situ, AIS）26例、微浸润腺癌（minimally invasive adenocarcinoma, MIA）17例、腺癌43例。将AAH和AIS归为非浸润（noninvasive cancer, NC）组，69例，MIA和腺癌归为浸润（invasive cancer, IC）组，共60例。通过绘制受试者工作曲线得出实性成分大小、肿瘤大小、C/T比值、m-CT值和Max CT值的cutoff值和曲线下面积，再通过单因素和多因素分析临床资料和CT参与与GGO恶性程度的相关性。结果 本研究共入组了129例患者，其中男性59例，女性70例，平均年龄（62.0±8.6）岁。两组患者在性别、年龄、分化程度方面没有差异无统计学意义（P>0.05）。通过绘制患者的实性成分大小、肿瘤大小、C/T比值、m-CT值和Max CT值的ROC曲线发现，上述指标的cutoff值分别为：9.4 mm、15.3 mm、47.5%、-469.0 HU和-35.0 HU，对应的AUC分别为：0.89、0.79、0.82、0.90、0.85，m-CT值的曲线下面积最大，对预测GGO恶性程度效果最佳。单因素和多因素分析发现，肿瘤大小、C/T比值、m-CT值和Max CT值均与GGO恶性程度有较强的相关性。结论 GGO大小、GGO中实性成分大小、Max CT值、m-CT值、C/T比值与GGO的恶性程度均有一定的相关性。m-CT值预测纯GGO的恶性程度的准确性相对最高，而对于混合密度的GGO病变，需要结合m-CT值、Max CT值及GGO大小来综合评估。 .
Keywords: Lung neoplams; ROC curve; Tomography; X-Ray computed.