Purpose or Case Report: Children’s interstitial lung diseases (chILD) comprise a large spectrum of rare diffuse lung disorders, with a subset of patients developing chronic fibrosing lung disease. While imaging criteria for lung fibrosis are established for adults and correlate with prognosis and outcome, there are limited data on imaging for diagnosis, prognosis, and outcomes in children with fibrotic lung disease. To fill this gap, a group of ILD specialists aimed to define the imaging features for diagnosis of lung fibrosis for a forthcoming randomized trial of nintedanib versus placebo in pediatric patients with fibrosing ILD (1199-0337; NCT04093024).
Methods & Materials: Imaging criteria for diagnosis of adult pulmonary fibrosis were reviewed by an international panel of radiologists and pulmonologists with experience in ILD and clinical trial application. High-resolution computed tomography (HRCT) scans from chILD cases with suspected fibrosis were reviewed and the adult imaging criteria adapted based on the characteristics observed. The resulting imaging criteria for lung fibrosis in chILD were agreed by expert consensus. In a case study, data driven texture analysis software (Humphries, Radiol 2017) was used to quantify the imaging criteria and changes over time on four longitudinal chest CT scans in a child with a genetic mutation of SFTPC.
Results: Study eligibility will be determined based on documented evidence of fibrotic lung disease by centrally confirmed HRCT. To qualify, patients need two longitudinal CT scans with at least two of: reticular abnormality, traction bronchiectasis, honeycombing, architectural distortion, or cystic abnormality. For patients with previous findings of fibrosis on lung biopsy, a single chest CT with either reticular abnormality, honeycombing, traction bronchiectasis, or architectural distortion will be sufficient. Ground glass opacity can be present but does not qualify as one of the fibrotic criteria. Findings from the case-study based on these imaging criteria appeared to show increased fibrosis over time.
Conclusions: Criteria for diagnosis of chronic fibrosing ILD in pediatric patients have been defined for evaluation in clinical trials. Case-study evaluation of changes over time suggests these criteria may also be useful to evaluate treatment response. Qualitative and quantitative methods will be used to assess fibrotic changes on chest CT in a sub-study of the planned clinical trial of nintedanib in children with lung fibrosis.