The growth feature and its diagnostic value for benign and malignant pulmonary nodules met in routine clinical practice

Abstract

Background: Growth rate is an independent risk factor for lung cancer in screened pulmonary nodules.This study aimed to clarify growth characteristics of pulmonary nodules in routine clinical practice and examine whether volume doubling time (VDT) can predict the malignancy of these nodules. Methods: We retrospectively enrolled patients with 5-30-mm-sized pulmonary nodules that had been surgically resected after a follow-up of at least 3 months. Two follow-up computed tomography (CT) images with similar thickness and long interval were obtained. Then, three-dimensional (3D) manual segmentation for all nodules was performed on two follow-up CT scans. Subsequently, VDT was calculated for nodules with a change in volume of at least 25%. Results: Overall, 305 pulmonary nodules in 305 patients (men, 36.7%; median age, 57) were included. The mean increased diameter, mass, and volume of benign (n=86) and malignant (n=219) nodules were 0.09 vs.2.37 mm, 0.10 vs. 0.66 g, and 32.74 vs. 1,871.28 mm3, respectively (P<0.05). In total, 24 of 86 benign nodules (28%, 18 grew and 6 shrank) and 121 of 219 malignant nodules (55%, 114 grew and 7 shrank) changed over time. The median VDTs of growing benign and malignant nodules were 389 and 526 days, respectively, (P=0.18), and the area under the receiver operating characteristic (ROC) curve was 0.67 (0.55-0.78), with a sensitivity and specificity of 69% and 58%, respectively. The median VDT for growing nodules was 339 days for inflammatory pseudotumors, 226 days for granulomas, 640 days for benign tumors, 1,541 days for enlarged lymph nodes, 762 days for adenocarcinoma in situ, 954 days for microinvasive adenocarcinoma, 534 days for invasive adenocarcinoma, and 118 days for squamous cell carcinoma. Conclusions: In routine clinical practice, many malignant nodules could grow slowly or even remain stable over time. Regarding growing nodules, the diagnostic value of VDT was limited.

Preoperative Changes of Lung Nodule on Computed Tomography and Their Relationship With Pathological Outcomes

“…A plenty of previous researches ( 10 , 13 , 24 , 25 ) have clarified that there are different growth patterns in lung cancer, among which some are stable whereas the others grow at fairly steady increments or demonstrated periods of accelerated growth. We presumed it a different case to talk about an increase in size and growth, and there might be other factors apart from growth that would show significant relevance with nodule malignancy and furthermore malignant grading.…”

“…In current practice, lung nodules identified by CT are managed according to the widely accepted guidelines that heavily rely on nodule size (4,(6)(7)(8)(9). While recently researchers found that growth rate of nodules (10) and solid portions (11,12) were also the risk factors of lung cancer, Lindell R. M. et al clarified different growing patterns of lung nodules that were then diagnosed as lung cancer at last (13). These indicated that regarding to nodule malignancy, it was far from enough for judgment with only the consideration of nodule size.…”

Solitary Pulmonary Inflammatory Nodule: CT Features and Pathological Findings

“…However, after studying the pathological findings, it revealed that types I and III SPINs may not grow significantly due to significant fibrous tissue proliferation and hyaline change. Thus, follow-up could provide more information for the likely diagnosis because most of malignant solid nodules will increase in size and/or density, 31 and such information should be added in an affected patient’s flowchart for discriminating SPINs from cancerous nodules.…”

Diameter versus volumetry: a narrative review on current recommendations to measure and monitor screening detected lung nodules

“…Growth of a PN refers to an increase in size between two given CT examinations. Nodule growth rate is considered an independent risk factor for LC in screen-detected PN, allegedly the strongest predictor of risk (77). The optimal prediction of the likelihood of LC is granted by longitudinal assessment of VDT (33).…”

“…Malignant PN tend to grow rapidly (VDT <400 days) but there are not strict rules. Benign PN might indeed show a rapid growth (VDT <400 days) as well as malignant ones might grow slowly (VDT >400 days) or even remain stable for a considerable period of time (77).…”