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Updated: Sep 21, 2025

Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy
Published on: June 7, 2015
CT Findings and Treatment Outcomes of Ground-Glass Opacity Predominant Lung Cancer After Stereotactic Body
Naoto Mikami1, Atsuya Takeda2, Aya Hashimoto3
1Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan; Department of Respiratory Medicine, Ofuna Chuo Hospital, Kamakura, Kanagawa, Japan.
Background:
Stereotactic body radiotherapy (SBRT) has been rapidly evolving and increasingly performed in patients with ground-glass opacity (GGO) predominant lung cancer (GGOp-LC).
Purpose:
To evaluate early-phase CT findings of GGOp-LC after SBRT.
Materials And Methods:
Patients with GGOp-LC staged as cTis-2bN0M0 treated with SBRT were retrospectively identified. The CT images were analyzed using radiologists' interpretation and CT-density histograms. Long-term treatment outcomes were also assessed.
Results:
This study evaluated 126 patients with 133 cases of GGOp-LC, comprising GGOp-LC with pure GGO (pureGGO-LC) (n = 31) and part-solid tumors (partsolid-LC) (n = 102). The median follow-up duration was 64.3 months (range, 10.8-178.9 months). Most GGOp-LC cases were interpreted as stable disease at 1 and 3 months after SBRT (96% [125/130] and 85% [62/73], respectively). However, the solid component was often interpreted as progressive disease (42% [34/82] and 60% [29/48], respectively). The GGO component was interpreted as denser in 47% (61/130) and 86% (63/73) of cases, respectively. For 25 evaluable pureGGO-LC cases at 3 months, the median tumor density values increased over time (P < .001). For 48 evaluable partsolid-LC cases at 3 months, the median areas of CT-density ≥ -160 HU increased over time (P < .001). The 5-year overall survival for GGOp-LC patients was 78.0%. No local or regional recurrence were observed.
Conclusion:
Clinical outcomes of SBRT for GGOp-LC were excellent, without local or regional recurrence. In the interpretation of early-phase follow-up CT scans of GGOp-LC after SBRT, it should be noted that most GGOp-LC remains stable disease, solid component increases in size, and GGO component is denser.

