Background: Since the popularization of computed tomography (CT) technology, the detection rate of pulmonary ground glass nodules (GGNs) with imaging follow-up as the main management method has increased significantly. The purpose of this study is to quantitatively analyze the changes of pulmonary GGNs during the follow-up process with three-dimensional reconstruction technology, explore the natural progression of pulmonary GGNs, and provide effective basis for clinical guidance for patients to conduct reasonable management of nodules.
Methods: A total of 115 cases of pulmonary GGNs with regular follow-up in the Combined Outpatient Department of Zhoushan Hospital from March 2015 to November 2022 were enrolled. Quantitative imaging features of nodules were extracted by semi-automatic segmentation of 3D Slicer software to evaluate the growth of nodules and clinical intervention during follow-up.
Results: The average baseline age of the patients was (56.9±10.1) yr. The mean follow-up time was (48.8±18.9) months. The two-dimensional diameter of baseline CT scan was (7.9±2.9) mm, and the maximum three-dimensional diameter was (10.1±3.4) mm. The two-dimensional diameter of the last CT scan was (9.9±4.7) mm, and the maximum three-dimensional diameter was (11.4±5.1) mm. A total of 27 cases (23.5%) showed an increase during follow-up, with a median volume doubling time of 822 days and a median mass doubling time of 1,007 days. 32 cases were surgically resected, including 6 cases of invasive adenocarcinoma (IAC), 16 cases of minimally invasive adenocarcinoma (MIA), 8 cases of adenocarcinoma in situ (AIS) and 2 cases of atypical adenomatous hyperplasia (AAH). Five nodules underwent surgical intervention due to the progression of two-dimensional diameter, which was pathologically confirmed as pre-invasive lesions, but their three-dimensional maximum diameter showed no significant change. Nodular morphology, lobulated sign, spiculated sign and vacuole signs all promoted the growth of nodules in univariate analysis. There were significant differences in age, baseline diameter, mean CT value, median CT value, 10% and 90% percentile CT number between the growth group and the stable group (P<0.05). Multivariate Logistic regression analysis showed that age and average CT value were risk factors for nodule growth (P<0.05). Receiver-operating characteristic (ROC) curve analysis results indicated that the age ≥63 years old, the baseline three-dimensional maximum diameter ≥9.2 mm, and the average CT value ≥-507.8 HU were more likely to accelerate the growth of GGNs. The maximum three-dimensional diameter ≥14.4 mm and the average CT value ≥-495.7 HU may be a higher malignant probability.
Conclusions: GGNs show an inert growth process, and the use of three-dimensional measurements during follow-up is of greater significance. For persistent glass grinding nodules ≥63 years old, the baseline three-dimensional maximum diameter ≥9.2 mm, and the average CT value ≥-507.8 HU are more likely to increase. However, most nodules still have good prognosis after progression, and long-term follow-up is safe.
【中文题目：基于三维重建技术的肺磨玻璃结节生长规律研究】 【中文摘要：背景与目的 自计算机断层扫描（computed tomography, CT）技术普及以来，影像学随访为主要管理方法的磨玻璃结节（ground glass nodules, GGNs）检出率明显增加，本研究旨在应用三维重建技术定量分析GGNs随访过程中的变化情况，探索GGNs自然进展规律，为临床指导患者合理地进行结节管理提供有效依据。方法 纳入2015年3月-2022年11月舟山医院肺结节联合门诊中规律随访的GGNs患者共115例。利用3D Slicer软件半自动分割提取结节的定量影像学特征，评估随访过程中的结节增长情况及临床干预情况。结果 患者平均基线年龄为（56.9±10.1）岁；平均随访时间为（48.8±18.9）个月。CT二维直径为（7.9±2.9）mm，三维最大径为（10.1±3.4）mm。末次CT扫描二维直径为（9.9±4.7）mm，三维最大径为（11.4±5.1）mm。共27例（23.5%）随访期间出现增长，中位体积倍增时间为822 d，中位质量倍增时间为1,007 d。手术切除32例，其中6例浸润性腺癌（invasive adenocarcinoma, IAC），16例微浸润腺癌（minimally invasive adenocarcinoma, MIA），8例原位腺癌（adenocarcinoma in situ, AIS），2例非典型腺瘤样增生（atypical adenomatous hyperplasia, AAH）。5例结节因二维直径显示进展而行手术干预，病理证实为浸润前病变，但其三维最大径提示无明显变化。单因素分析结果显示形态不规则、边缘欠光整，具有分叶、毛刺、空泡征均为促进结节增长的因素；增长组与稳定组年龄、基线直径和平均CT值、中位CT值、10%位数CT值、90%位数CT值差异具有统计学意义（P<0.05）。多因素Logistic回归分析结果表明年龄和平均CT值是影响结节增长的危险因素（P<0.05）。受试者工作特征（receiver-operating characteristic, ROC）曲线分析结果提示年龄≥63岁、基线三维最大径≥9.2 mm、平均CT值≥-507.8 HU的GGNs出现增长的可能性更大；三维最大径≥14.4 mm、平均CT值≥-495.7 HU时恶性概率更高。结论 GGNs呈惰性生长过程，随访过程中应用三维测量值意义更大，对于持续存在的GGNs年龄≥63岁、基线三维最大径≥9.2 mm、平均CT值≥-507.8 HU出现增长的可能性更大，但多数结节出现进展后仍预后良好，长期随访是安全的。 】 【中文关键词：肺磨玻璃结节；计算机断层扫描；随访；三维重建】.
Keywords: Computed tomography; Follow-up; Pulmonary ground glass nodules; Three-dimensional reconstruction.