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

Background: This pilot study evaluated the effect of short-and long-term ivacaftor treatment on hyperpolarized He-3-magnetic resonance imaging (MRI) defined ventilation defects in patients with cystic fibrosis aged >= 12 years with a G551D-CFTR mutation. Methods: Part A (single-blind) comprised 4 weeks of ivacafior treatment; Part B (open-label) comprised 48 weeks 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: TVD responded to ivacaftor therapy. He-3-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. (C) 2016 The Authors. Published by Elsevier B.V. on behalf of European Cystic Fibrosis Society.