論文No1805
Quantitative high-resolution computed tomography fibrosis score: performance characteristics in idiopathic pulmonary fibrosis
Stephen M. Humphries, Jeffrey J. Swigris, Kevin K. Brown, Matthew Strand, Qi Gong, John S. Sundy, Ganesh Raghu, Marvin I. Schwarz, Kevin R. Flaherty, Rohit Sood, Thomas G. O'Riordan, David A. Lynch
European Respiratory Journal 52 (3) 1801384; DOI: 10.1183/13993003.01384-2018 Published 17 September 2018
＜背景＞
特発性肺線維症(IPF)患者において、高解像度CT(HRCT)による肺線維化の測定を
data-driven texture analysis(DTA)の最小臨床重要相違(MCID)で評価した。
＜方法＞
ベースラインと54-60週のHRCTデータのある２つの介入臨床試験のIPF患者141名の解析である。
DTAスコアはCTから計算し、強制肺活量(FVC)、拡散能、6分間歩行テスト、SGRQスコアとの関連を検討した。
DTAの信頼度、検証、反応性を調べた。アンカーおよび分布法によりMCIDを評価した。
＜結果＞
DTAは一見安定している患者でフォローアップ時点でアンカー変数で許容できる信頼性があった。
DTAスコアと他の臨床検査値のベースラインの相関は中等度から弱かった。
DTAスコアの変化と他のパラメータの変化との相関には、
中等度から弱い許容できる反応性が認められた。
FVCをアンカーとすると、MCIDは3.4%と計算された。
＜感想＞
肺線維化の程度をHRCTのデジタル解析で定量化することは信頼性が高く、
3.4%増加すると臨床的に重要な変化になったようです。
We evaluated performance characteristics and estimated the minimal clinically important difference (MCID) of data-driven texture analysis (DTA), a high-resolution computed tomography (HRCT)-derived measurement of lung fibrosis, in subjects with idiopathic pulmonary fibrosis (IPF).
The study population included 141 subjects with IPF from two interventional clinical trials who had both baseline and nominal 54- or 60-week follow-up HRCT. DTA scores were computed and compared with forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide, distance covered during a 6-min walk test and St George's Respiratory Questionnaire scores to assess the method's reliability, validity and responsiveness. Anchor- and distribution-based methods were used to estimate its MCID.
DTA had acceptable reliability in subjects appearing stable according to anchor variables at follow-up. Correlations between the DTA score and other clinical measurements at baseline were moderate to weak and in the hypothesised directions. Acceptable responsiveness was demonstrated by moderate to weak correlations (in the directions hypothesised) between changes in the DTA score and changes in other parameters. Using FVC as an anchor, MCID was estimated to be 3.4%.
Quantification of lung fibrosis extent on HRCT using DTA is reliable, valid and responsive, and an increase of ∼3.4% represents a clinically important change.