CHEST Guidelines-Polarization-Sensitive-Optical-Coherence-Tomograph

Polarization-Sensitive-Optical-Coherence-Tomograph

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This study examines the use of polarization-sensitive optical coherence tomography (PS-OCT) for detecting airway smooth muscle (ASM) in patients with severe asthma treated by bronchial thermoplasty (BT). Asthma involves chronic inflammation and airway remodeling (AR), characterized by thickening of ASM. BT is an endoscopic treatment aimed at reducing ASM to alleviate asthma symptoms in severe cases. Traditional assessment methods for AR involve invasive airway biopsies, but PS-OCT presents a minimally invasive alternative. PS-OCT generates high-resolution cross-sectional images and utilizes tissue birefringence for ASM detection and quantification.<br /><br />In a pilot study, PS-OCT was used to visualize and measure ASM in patients enrolled in the TASMA trial, which investigates BT's efficacy in severe asthma. PS-OCT imaging was conducted on the right lower lobe and untreated middle lobe of three patients six months post-BT. In one case, imaging also occurred pre-BT. No adverse events arose from the imaging process, suggesting it is safe and feasible.<br /><br />Analysis revealed that PS-OCT could detect ASM reduction after BT, correlating with biopsy results. A significant linear correlation between ASM content measured by PS-OCT and in biopsies was established, demonstrating PS-OCT's accuracy for assessing ASM mass. The study also provided 3D reconstructions of ASM changes pre- and post-BT, highlighting reduction in proximal airway areas most affected by BT.<br /><br />The study concludes that PS-OCT is a promising tool for assessing ASM in patients with severe asthma, although further validation in larger patient cohorts is necessary. This method offers a new, less invasive approach to evaluating ASM changes and the effectiveness of BT in treating airway remodeling in asthma.

Keywords

polarization-sensitive optical coherence tomography

PS-OCT

airway smooth muscle

ASM

severe asthma

bronchial thermoplasty

airway remodeling

TASMA trial

minimally invasive