Case Study: Late Emergence of Ablation Margin Following CT-Guided Microwave Ablation of a Solid Lung Nodule

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CT-guided thermal ablation requires a circumferential increased-attenuation margin of 5–10 mm beyond the tumor as an intraprocedural endpoint.
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In a case study, a solid lung nodule showed no increased-attenuation margin immediately after microwave ablation despite adequate energy delivery.
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Imaging 30.5 hours post-ablation revealed a delayed margin and consolidation, indicating that absence of the margin does not always imply underablation.
4

The absence of the guideline-defined margin during the standard observation window raises questions about management and frequency in solid nodules.
5

Consensus guidelines define the ablation zone broadly, allowing for various attenuation patterns, not strictly adhering to the radiologic definition of ground-glass opacity.

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