Evaluation of Radiation Dose Effect on Lung Function Using Iodine Maps Derived From Dual-Energy Computed Tomography

Area of Science:

• Radiology and Imaging
• Pulmonary Medicine
• Radiation Oncology

Background:

• Dual-energy computed tomography (DECT) is being explored for evaluating organ function post-radiation therapy (RT).
• Assessing longitudinal changes in lung perfusion is crucial for understanding RT effects.

Purpose of the Study:

• To assess longitudinal changes in lung perfusion using DECT-derived iodine maps.
• To evaluate these changes in lung cancer patients treated with conventional or stereotactic RT.

Main Methods:

• 48 lung cancer patients underwent contrast-enhanced DECT before and after RT.
• Iodine maps were generated, and normalized functional responses (NFR) were calculated based on radiation dose.
• Mixed model and Pearson correlation analyses assessed relationships between dose, NFR, and pulmonary function tests (PFT).

Main Results:

• Normalized functional response (NFR) showed a linear correlation with radiation dose (P < .001).
• Time elapsed post-RT also correlated with NFR (P = .029), but not in the stereotactic RT subgroup.
• NFR did not correlate with changes in pulmonary function tests (PFT).

Conclusions:

• DECT-derived iodine maps offer a promising method for evaluating radiation effects on lung function.
• This technique may help detect subclinical changes in lung perfusion after RT.