Digital Tomosynthesis Effectively Estimates Structural Lung Disease in Cystic Fibrosis

Digital tomosynthesis (DTS) of the chest, a modality developed on the basis of the same technique used in conventional radiography, offers effective quantitative estimation of structural lung disease in patients with cystic fibrosis (CF), according to study results published in Radiation Protection Dosimetry.

A team of researchers from Sweden and Norway included 31 patients from a CF center who were undergoing routine surveillance in this observational study between 2011 and 2017. Participants underwent computed tomography (CT) as well as DTS as part of their routine triannual follow-up. Modality-specific scoring systems were used to assess the extent of disease. Additionally, pulmonary function tests (PFTs) were performed. Overall, the study included 186 examinations at baseline and follow-up using DTS, CT, and PFTs.

In the overall patient population, the median duration from baseline to follow-up examination was 3.0 years. At baseline, the median effective doses for DTS and CT were 0.14 mSv and 2.68 mSv, respectively. In the follow-up examinations, the median effective doses were 0.13 mSv for DTS and 1.42 mSv for CT.

The baseline and follow-up Spearman’s rank correlation coefficients between total scores for DTS and CT were 0.89 and 0.86, respectively (P <.01). Intermodality correlation was also considered very strong for subscores of bronchiectasis (r=0.82-0.92; P <.01) and bronchial wall-thickening (r=0.82-0.87; P <.01). The interobserver reliability was also considered high for total score (α=0.83; 95% CI, 0.76-0.89), bronchiectasis (α= 0.93; 95% CI, 0.89-0.96), and mucus plugging (α=0.85; 0.74-0.93) in DTS.

According to the investigators, using modality-specific scoring systems with observers that possessed expert knowledge of these scoring system may have limited the generalizability of the findings across observers who lack such expertise. Additionally, the study was limited by its single-center design.

Based on their findings, the investigators concluded that “DTS might be an easy accessible, low dose alternative to standard CT in imaging of patients with CF.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Meltzer C, Gilljam M, Vikgren J, et al. Quantification of pulmonary pathology in cystic fibrosis—comparison between digital chest tomosynthesis and computed tomography. Radiat Prot Dosimetry. Published online March 4, 2021.  doi:10.1093/rpd/ncab017