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

BACKGROUND: He-magnetic resonance imaging (MRI)-defined ventilation defects in patients with cystic fibrosis aged ≥12years with a G551D-CFTR mutation. METHODS: Part 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). RESULTS: Mean 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. CONCLUSIONS: He-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.