Diameter thresholds for pure ground-glass pulmonary nodules at low-dose CT screening: Chinese experience

Q: How did changing the diameter threshold affect sensitivity and specificity?

Increasing the threshold from 5 mm to 8 mm improved specificity and positive predictive value but reduced sensitivity. Raising further from 8 mm decreased sensitivity while slightly increasing specificity and PPV.

Q: Why is the 8 mm threshold considered more useful clinically in this study?

Decision curve analysis indicated that the predictive model using an 8 mm threshold had greater clinical utility than models using other thresholds, while AUC patterns showed comparable category performance at 8 mm.

Sep 23, 2026

Uploaded by Oliver

Limited research has examined diameter thresholds for detecting malignant pure ground-glass lung nodules (pGGNs) using low-dose CT screening in the Chinese population. A retrospective Guangzhou Lung-Care study retrieved average transverse diameter, location, histopathology, nodule frequency, and follow-up intervals. Diagnostic performance across 5–10 mm thresholds was assessed with AUC, decision curve analysis, sensitivity, and specificity. Malignancies were grouped into MIA+IA, AAH+AIS+MIA+IA, and IA-only. Results showed improved specificity and PPV up to 8 mm with acceptable sensitivity trade-offs, and decision curve analysis supported the 8 mm model.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages10

Reading Time25 min

AccessFree to download

ABSTRACT

Background

Materials and methods

Thresholds and diagnostic evaluation

Results

Performance trends across thresholds

Conclusions

Trial registration

Lung cancer Original research Diameter thresholds for pure ground-glass pulmonary nodules at low-dose CT screening: Chinese experience Wenjun Ye , 1,2 Wenhai Fu, 1 Caichen Li, 1 Jianfu Li, 1 Shan Xiong, 1 Bo Cheng, 1 Bin Xu,3 Qixia Wang,4 Yi Feng , 1 Peiling Chen , 1 Jianxing He , 1 Wenhua Liang 1,2 ► Additional supplemental material is published online only. To view, please visit the journal online ([https://doi](https://doi). org/10.1136/thorax-2024- 221642) . For numbered affiliations see end of article. Correspondence to Professor Jianxing He; drjianxing. he@gmail.com and Dr Wenhua Liang; [liangwh1987@163.com](liangwh1987@163.com) WY, WF and CL contributed equally. WY, WF and CL are joint first authors. JH and WL are joint senior authors. Received 5 March 2024 Accepted 27 October 2024 © Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. To cite: Ye W, Fu W, Li C, et al. Thorax Epub ahead of print: [please include Day Month Year] . doi:10 . 1136/ thorax-2024-221642 ABSTRACT Background Limited research exists on screening thresholds for low-dose CT in detecting malignant pure ground-glass lung nodules (pGGNs) in the Chinese population. Materials and methods A retrospective analysis of the Guangzhou Lung-Care programme was conducted, retrieving average transverse diameter, location, histopathology, frequency and follow-up intervals. Diagnostic performances for ’lung cancers’were evaluated using areas under the curve (AUCs), decision curve analysis (DCA), sensitivities and specificities, with thresholds ranging from 5 mm to 10 mm. We divide malignant pGGNs into three groups: (1) minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA),(2) atypical adenomatous hyperplasia (AAH) and adenocarcinoma in situ (AIS) and MIA and IA and (3) IA-only. Results In ’MIA+IA’, increasing the threshold from 5 mm to 8 mm improved specificity (60 .97% to 88.85%, p<0 .001) and positive predictive values (PPVs; 5.87% to 14.88%, p<0 .001), but decreased sensitivity (94 .44% to 75 . 56%, p<0 .001) . Further raising threshold from 8 mm reduced sensitivity (75 . 56% to 60.00%, p<0 .001), while slightly increasing specificity (88 .85% to 93 .47%, p<0 .001) and PPVs (14 .88% to 19. 15%, p<0 .001) . Increasing threshold from 5 mm to 7 mm enhanced the AUC for ’MIA+IA’ (from 0.711 to 0.829),’AAH+AIS+MIA+IA’ (from 0.748 to 0 .804) and’IA-only’(from 0.783 to 0 .833) . At 8 mm, the AUCs for these categories were similar. However, increasing the threshold from 7 mm to 10 mm resulted in reduced AUCs for ’MIA+IA’ (0 .829 to 0. 767),’AAH+AIS+MIA+IA’(0 .804 to 0 . 744) and ’IA-only’(0 .833 to 0 .800) . DCA reveals that the 8 mm predictive model demonstrates greater clinical utility compared with models with other thresholds. Conclusions Increasing the diameter threshold for positive results for pGGNs, up to 8 mm could enhance diagnostic performance. Trial registration number NCT04938804 . INTRODUCTION The advent of low-dose CT (LDCT) has significantly increased the detection of pure groundglass nodules (pGGNs) in regions like China.1–3 These pGGNs, which may be transient or evolve | WHAT IS ALREADY KNOWN ON THIS TOPIC
⇒ Prior studies, including the National Lung Screening Trial, the International Lung Screening Trial, the Early Lung Cancer Action Project (ELCAP), and extensions like New York-ELCAP and International-ELCAP, as well as the NELSON trial, have primarily focused on semi-solid and solid nodules. This research emphasis has led to a lack of specific early screening cohorts for pure ground-glass nodules, a gap this paper seeks to address by exploring diameter thresholds in low-dose CT (LDCT) screenings.
WHAT THIS STUDY ADDS | | --- | | ⇒ Raising the diameter threshold for identifying malignant pure ground-glass nodules (pGGNs) from 5 mm to 8 mm LDCT scans improves diagnostic specificity and po

FAQs

What population and study design were used to evaluate CT diameter thresholds for pGGNs?

A retrospective analysis of the Guangzhou Lung-Care programme was conducted, using retrieved nodule measurements, histopathology, frequency, and follow-up intervals to assess diagnostic performance.

How did changing the diameter threshold affect sensitivity and specificity?

Increasing the threshold from 5 mm to 8 mm improved specificity and positive predictive value but reduced sensitivity. Raising further from 8 mm decreased sensitivity while slightly increasing specificity and PPV.

Why is the 8 mm threshold considered more useful clinically in this study?

Decision curve analysis indicated that the predictive model using an 8 mm threshold had greater clinical utility than models using other thresholds, while AUC patterns showed comparable category performance at 8 mm.

Sep 23, 2026

Uploaded by Oliver