Multicentre chest computed tomography standardisation in children and adolescents with cystic fibrosis: the way forward

Abstract

Progressive cystic fibrosis (CF) lung disease is the main cause of mortality in CF patients. CF lung disease starts in early childhood. With current standards of care, respiratory function remains largely normal in children and more sensitive outcome measures are needed to monitor early CF lung disease. Chest CT is currently the most sensitive imaging modality to monitor pulmonary structural changes in children and adolescents with CF. To quantify structural lung disease reliably among multiple centres, standardisation of chest CT protocols is needed. SCIFI CF (Standardised Chest Imaging Framework for Interventions and Personalised Medicine in CF) was founded to characterise chest CT image quality and radiation doses among 16 participating European CF centres in 10 different countries. We aimed to optimise CT protocols in children and adolescents among several CF centres. A large variety was found in CT protocols, image quality and radiation dose usage among the centres. However, the performance of all CT scanners was found to be very similar, when taking spatial resolution and radiation dose into account. We conclude that multicentre standardisation of chest CT in children and adolescents with CF can be achieved for future clinical trials.

Chest imaging in cystic fibrosis studies: What counts, and can be counted?

“…To date, over 20 observers have been trained in the Erasmus MC LungAnalysis Core Laboratory using the CF-CT method. It has been used in multiple studies to validate chest CT as an outcome (6, 17–20). An advantage of scoring systems like CF-CT is that the lung volume level during CT acquisition is not very critical for the magnitude of the scores (21) (22).…”

“…More recently, the Airway-Artery (AA) method was developed for the sensitive and automated analysis of all visible airway artery pairs. It is likely that this system eventually will take over the scoring of airway abnormalities (Kuo and colleagues, 2016, work in press and other under review).…”

“…For these children, scans acquired at a volume level near functional residual volume are less sensitive, compared to inspiratory scans for the detection of airway disease. Equally important factors to consider include radiation dose, pitch, reconstruction kernels, and slice thickness; all of which are known to influence image quality(17) and can be accounted for in prospective studies.…”

“…To track disease over time, ideally the same volume and CT protocol should be used when follow up CTs are compared to baseline CTs. Recent work highlights the importance of standardization in multicenter studies using CT(17). In addition to previously mentioned longitudinal validation studies, assessment of standardization techniques are also needed for MRI.…”

“…Given the current findings on standardization for each modality, CT and MRI markers may be feasible for Phase III and single center Phase II studies, respectively. There is now a CTN-TDN task force, composing guidelines that will further harmonize study protocol recommendations, complimenting existing efforts in the European Union that have been published (17) and are under review for CT. Similar efforts have recently been initiated for MRI.…”