Los Angeles -- A new SPECT/CT imaging approach can
accurately differentiate inflammation from fibrosis in interstitial lung disease
(ILD) patients, according to new research presented at the Society of Nuclear
Medicine and Molecular Imaging 2026 Annual Meeting. This molecular imaging
technique has the potential to determine which patients would benefit from
anti-inflammatory treatments and which would likely only experience harmful
side effects.
ILD includes more than 200 different types of lung conditions,
and affects approximately 650,000 people in the United States, resulting in an
estimated 25,000 to 30,000 deaths per year. Differentiating between fibrotic
scarring and inflammation stages of disease is critical so that physicians can
determine what treatment is best for the patient.
"We saw during the Covid-19 pandemic -- when all patients with
the infection had inflammation that anti-inflammatory treatments were highly
effective," said Druin Burch, consultant physician at John Radcliffe Hospital
in Oxford, United Kingdom. "While current imaging techniques can provide a
structural view of fibrosis in the lungs, there is no reliable, non-invasive
way to identify inflammation. A tool that could detect inflammation in ILD
patients could help pinpoint those most likely to respond to anti-inflammatory
therapy."
Researchers investigated the molecular imaging agent ⁹⁹ᵐTc-maraciclatide, which visualizes the formation of
new blood vessels a cardinal feature of inflammatory disease. A total of 15
patients, five with idiopathic pulmonary fibrosis, five with fibrotic
hypersensitivity pneumonitis, and five healthy controls, underwent ⁹⁹ᵐTc-maraciclatide SPECT/CT. Nuclear medicine
physicians and thoracic radiologists classified the images based on
radiological patterns, standardized uptake values, and target-to-background
ratios.
The healthy controls showed minimal
tracer uptake in the lungs, whereas both groups of patients with ILD
demonstrated distinct uptake. The target-to-background ratio was also numerically
higher in the lung disease cohorts compared to the healthy
controls.
"Being able to differentiate the fibrotic and inflammation
stages of ILD is not just beneficial to inform treatment decisions, but also
for the development new therapies," said Burch. "This approach has the
potential to unlock a wide range of anti-inflammatory drugs for
ILD."
A Phase 3 study in a larger patient population is required
before this imaging approach can be used outside the research setting. As ⁹⁹ᵐTc‑maraciclatide has received FDA Fast Track
designation for imaging ILD, it could become available to patients within two
years of initiating a Phase 3 trial.