Use of hyperpolarized helium-3 MRI to assess response to ivacaftor treatment in patients with cystic fibrosis

Abstract

BackgroundThis pilot study evaluated the effect of short- and long-term ivacaftor treatment on hyperpolarized 3He-magnetic resonance imaging (MRI)–defined ventilation defects in patients with cystic fibrosis aged ≥12years with a G551D-CFTR mutation. MethodsPart A (single-blind) comprised 4weeks of ivacaftor treatment; Part B (open-label) comprised 48weeks of treatment. The primary outcome was change from baseline in total ventilation defect (TVD; total defect volume:total lung volume ratio). ResultsMean change in TVD ranged from −8.2% (p=0.0547) to −12.8% (p=0.0078) in Part A (n=8) and −6.3% (p=0.1953) to −9.0% (p=0.0547) in Part B (n=8) as assessed by human reader and computer algorithm, respectively. ConclusionsTVD responded to ivacaftor therapy. 3He-MRI provides an individual quantification of disease burden that may be able to detect aspects of the disease missed by population-based spirometry metrics. Assessments by human reader and computer algorithm exhibit similar trends, but the latter appears more sensitive.www.clinicaltrials.gov identifier: NCT01161537