WCLC 2025 - Posters & ePosters-EP.04.12 Outcome of Lung RADS Category 4 in Lung Cancer Screening Population at Tertiary Hospital, Single Center Study

EP.04.12 Outcome of Lung RADS Category 4 in Lung Cancer Screening Population at Tertiary Hospital, Single Center Study

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This single-center study conducted at a tertiary hospital in Korea assessed outcomes of Lung-RADS Category 4 lesions detected in a lung cancer screening population using low-dose CT scans over 14 months. Among 2,374 screened individuals (male predominant, 4.5:1 ratio), distribution of Lung-RADS categories was: Category 1 (37.5%), 2 (49.4%), 3 (6.6%), and combined Category 4 subgroups (4A, 4B, 4X) accounting for 6.4%.<br /><br />Follow-up of 140 Category 4 nodules showed that 6.4% (9 cases) were confirmed as lung cancer: 2.1% in 4A, 3.6% in 4B, and 1 case in 4X. Most lesions were solid (134) or part-solid nodules; atypical cysts with ground-glass nodules were less common. Imaging features such as fuzzy margins and transient ground-glass opacities particularly in subsolid nodules (frequent in 4A) posed diagnostic challenges, indicating the importance of considering nodule shape alongside size and density for malignancy risk stratification.<br /><br />Significant concurrent findings included interstitial lung abnormalities (ILA) in 47 patients, emphysema in 24, and coronary calcification of varying severity in 68. Notably, prior tuberculosis infection appeared in 89 of 153 patients with Category 3 lesions, with active tuberculosis in 6 cases. Lung cancer diagnosis in Category 3 nodules was 5.9% during follow-up.<br /><br />The study underscores the role of Lung-RADS, particularly Category 4, in identifying high-risk nodules requiring timely follow-up, and validates management guidelines including revised Lung-RADS v2022 recommendations for subcategories and infectious findings. Limitations include single-center design, limited sample size, and loss to follow-up in 13 cases. Further research incorporating morphological parameters is suggested to enhance differentiation between benign and malignant nodules, improving screening efficacy in lung cancer early detection.

Asset Subtitle

Soo-Youn Ham

Meta Tag

Speaker Soo-Youn Ham

Topic Screening and Early Detection

Keywords

Lung-RADS

lung cancer screening

low-dose CT

Category 4 nodules

lung cancer diagnosis

subsolid nodules

interstitial lung abnormalities

emphysema

tuberculosis infection

lung nodule management