Objectives: Low dose computed tomography (LDCT) is the best method for early diagnosis of lung cancer. Even though it has been widely used in clinic, the selection of screening objects and the management scheme of pulmonary nodules are still not unified among research institutions. This study aims to evaluate the effect of LDCT in detection effect and follow-up process for pulmonary nodules in asymptomatic participants.
Methods: A total of 1 600 asymptomatic participants (37 to 82 years old), who came from Yantian District People's Hospital, Southern University of Science and Technology, received LDCT. The lung nodules were categorized into positive nodules and semi-positive nodules, and according to the density of positive nodules they were categorized into 4 types: solid nodules (SN), partial solid nodules (pSN), pure ground glass nodules (pGGN), and pleural nodules (PN). The number, detection rate, imaging findings, follow-up change of lung nodules, and the postoperative pathological results of positive nodules were recorded and analyzed.
Results: Lung nodules were found in 221 cases by LDCT. The total detection rate of lung nodule was 13.8% (221/1 600), and the detection rate in positive nodules was 4.9% (79/1 600). The detected nodules were mainly single (173 cases), solid (133 cases) and semi-positive nodules (142 cases). Most of nodules (177 cases) had no change in the follow-up process. The enlargement and/or increased density of nodules (5 cases) were lung cancer. Pathological results were obtained in 10 cases, 8 cases were malignant (1 small cell lung cancer and 7 adenocarcinomas), 2 cases were benign (cryptococcal infection and alveolar epithelial dysplasia). The detection rate of lung cancer was 0.5% (8/1 600), and the proportion of early lung cancer was 75% (6/8).
Conclusions: LDCT screening can identify and increase the detection rate in the early lung cancer, which is an effective screening method. It is safe and feasible to take regular follow-up and re-examination for nodules with diameter less than 5 mm. When the size and or density of nodule increases, it indicates the malignant prognosis of the nodule and timely clinical intervention is needed.
目的: 低剂量计算机体层摄影(low-dose computed tomography，LDCT)是目前肺癌早期诊断的较好的检查方法，虽在临床上已经得到了广泛应用，但筛查对象的选择及肺结节的管理方案在各研究机构间仍不统一。本研究探讨LDCT在无症状体检者中检出肺结节的效果及肺结节的随访流程。方法: 1 600例南方科技大学盐田区人民医院37~82岁无症状体检者接受LDCT筛查，筛查出的肺结节分成阳性结节、半阳性结节；再将阳性结节根据密度不同分为实性结节、部分实性结节、纯磨玻璃结节和胸膜结节，记录不同类型肺结节的检出数、影像表现、随访过程的变化情况，统计阳性结节术后的病理结果。结果: LDCT筛查共检出肺结节221例，检出率为13.8%；其中阳性结节79例，检出率为4.9%。检出的结节以单发(173例)、实性(133例)、半阳性结节(142例)为主，结节随访过程无变化者(177例)居多，结节增大和或密度增高(5例)均为肺癌。术后随访取得病理结果10例，8例为肺癌(1例小细胞肺癌和7例腺癌)，另外2例为良性病变(隐球菌感染和肺泡上皮不典型增生)。肺癌检出率为0.5%(8/1 600)，早期肺癌所占比例为75%(6/8)。结论: 采用LDCT对无症状体检者进行筛查有助于肺癌的早期发现，并能提高早期肺癌的检出率，是一种有效的筛查手段。对直径小于5 mm结节采取定期随访复查是安全可行的，结节增大和/或密度增高提示结节恶性转归，临床上需要进行及时的干预。.
Keywords: low-dose computed tomography; lung cancer; screening.