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Updated: Mar 17, 2026

Lung CT Segmentation to Identify Consolidations and Ground Glass Areas for Quantitative Assesment of SARS-CoV Pneumonia
Published on: December 19, 2020
Long-term Outcomes of Patients With Ground-Glass Opacities Detected Using CT Scanning
Shigeki Sawada1, Natsumi Yamashita2, Ryujiro Sugimoto1
1Department of Thoracic Surgery, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan.
Background:
The long-term outcomes of follow-up care for ground-glass opacity (GGO) lesions need to be clarified.
Methods:
Between 2000 and 2005, a total of 226 patients with pure or mixed GGO lesions ≤ 3 cm in size were registered. The CT findings and changes in the findings during the follow-up period and the outcomes of the 226 patients were subsequently reviewed.
Results:
Overall, 124 patients underwent resections, 57 did not receive follow-up examinations after 68 months because of stable disease or disease reduction, and 45 are continuing to receive follow-up examinations. Thirty-nine patients exhibited tumor growth during the follow-up period. Among the patients with a ratio of the diameter of consolidation relative to the tumor diameter (CTR) > 0, all cases with tumor growth were identified within 3 years; meanwhile, > 3 years were required to identify tumor growth in 16% of the patients with a CTR of 0. Aggressive cancer occurred in 4% of patients with a CTR of 0 and in 70% of patients with a CTR > 25%. Aggressive cancer was observed in 46% of the patients whose CTR increased during the follow-up period and in 8% of the patients whose tumors increased in size.
Conclusions:
A higher CTR and an increase in CTR during follow-up were associated with invasive cancer. A follow-up period of 3 years is considered to be adequate for judging tumor growth in patients with a CTR > 0, whereas a longer follow-up period might be needed for patients with a CTR of 0.
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