Radiation-Induced Lung Calcification: A Potential Mimic of Cancer Recurrence

Thoracic radiation therapy can cause radiation pneumonitis (1–6 months post-RT) → fibrosis → dystrophic calcification. These calcified foci appear on CT as dense nodules or linear densities, potentially mimicking metastatic disease or recurrence.

Key Points

• Calcification is a benign sequela of radiation injury.
• Stable or slowly evolving appearance favors benignity.
• PET-CT, serial imaging, and clinical correlation differentiate from malignancy.
• Multidisciplinary tumor board review recommended for ambiguous findings.