Rationale
Despite evidence demonstrating a prognostic role for computed tomography (CT) scans in idiopathic pulmonary fibrosis (IPF), image-based biomarkers are not routinely used in clinical practice or trials.
Objectives
To develop automated imaging biomarkers using deep learning–based segmentation of CT scans.
Methods
We developed segmentation processes for four anatomical biomarkers, which were applied to a unique cohort of treatment-naive patients with IPF enrolled in the PROFILE (Prospective Observation of Fibrosis in the Lung Clinical Endpoints) study and tested against a further United Kingdom cohort. The relationships among CT biomarkers, lung function, disease progression, and mortality were assessed.
Measurements and Main Results
Data from 446 PROFILE patients were analyzed. Median follow-up duration was 39.1 months (interquartile range, 18.1–66.4 mo), with a cumulative incidence of death of 277 (62.1%) over 5 years. Segmentation was successful on 97.8% of all scans, across multiple imaging vendors, at slice thicknesses of 0.5–5 mm. Of four segmentations, lung volume showed the strongest correlation with FVC (
r
= 0.82;
P
< 0.001). Lung, vascular, and fibrosis volumes were consistently associated across cohorts with differential 5-year survival, which persisted after adjustment for baseline gender, age, and physiology score. Lower lung volume (hazard ratio [HR], 0.98 [95% confidence interval (CI), 0.96–0.99];
P
= 0.001), increased vascular volume (HR, 1.30 [95% CI, 1.12–1.51];
P
= 0.001), and increased fibrosis volume (HR, 1.17 [95% CI, 1.12–1.22];
P
< 0.001) were associated with reduced 2-year progression-free survival in the pooled PROFILE cohort. Longitudinally, decreasing lung volume (HR, 3.41 [95% CI, 1.36–8.54];
P
= 0.009) and increasing fibrosis volume (HR, 2.23 [95% CI, 1.22–4.08];
P
= 0.009) were associated with differential survival.
Conclusions
Automated models can rapidly segment IPF CT scans, providing prognostic near and long-term information, which could be used in routine clinical practice or as key trial endpoints.
