OXFORD — Researchers at Oxford tested a new SPECT/CT imaging approach using the molecular imaging agent ⁹⁹ᵐTc-maraciclatide that can accurately differentiate inflammation from fibrosis in interstitial lung disease (ILD) patients. All 15 participants in the study—five with idiopathic pulmonary fibrosis, five with fibrotic hypersensitivity pneumonitis, and five healthy controls—underwent ⁹⁹ᵐTc-maraciclatide SPECT/CT imaging.
The imaging agent visualizes the formation of new blood vessels, a hallmark of inflammatory disease. Nuclear medicine physicians and thoracic radiologists analyzed the scans using radiological patterns, standardized uptake values, and target-to-background ratios. Healthy controls showed minimal tracer uptake in the lungs, while both ILD patient groups demonstrated distinct uptake of the tracer. The target-to-background ratio was numerically higher in the lung disease cohorts compared to the healthy controls.
Current imaging techniques can depict structural changes related to fibrosis but lack a reliable, non-invasive method to identify active inflammation. The new approach addresses this gap by targeting biological processes linked to inflammation rather than anatomy alone. Interstitial lung disease encompasses more than 200 distinct lung conditions, affects approximately 650,000 people in the United States, and results in an estimated 25,000 to 30,000 deaths annually.
“Being able to differentiate the fibrotic and inflammation stages of ILD is not just beneficial to inform treatment decisions, but also for the development of new therapies,” said Druin Burch, a consultant physician. “This approach has the potential to unlock a wide range of anti-inflammatory drugs for ILD.”
The U.S. Food and Drug Administration has granted ⁹⁹ᵐTc-maraciclatide Fast Track designation for imaging interstitial lung disease. A Phase 3 study in a larger patient population is required before the imaging approach can be used outside the research setting. If a Phase 3 trial begins soon, the technique could become available to patients within two years of its initiation.