The quantitative assessment of interstitial lung disease with positron emission tomography scanning in systemic sclerosis patients

Rheumatology (Oxford). 2020 Jun 1;59(6):1407-1415. doi: 10.1093/rheumatology/kez483.


Objectives: The reversibility of interstitial lung disease (ILD) in SSc is difficult to assess by current diagnostic modalities and there is clinical need for imaging techniques that allow for treatment stratification and monitoring. 18F-Fluorodeoxyglucose (FDG) PET/CT scanning may be of interest for this purpose by detection of metabolic activity in lung tissue. This study aimed to investigate the potential role of 18F-FDG PET/CT scanning for the quantitative assessment of SSc-related active ILD.

Methods: 18F-FDG PET/CT scans and high resolution CT scans of eight SSc patients, including five with ILD, were analysed. For comparison, reference groups were included: eight SLE patients and four primary Sjögren's syndrome (pSS) patients, all without ILD. A total of 22 regions of interest were drawn in each patient at apical, medial and dorsobasal lung levels. 18F-FDG uptake was measured as mean standardized uptake value (SUVmean) in each region of interest. Subsequently, basal/apical (B/A) and medial/apical (M/A) ratios were calculated at patient level (B/A-p and M/A-p) and at tissue level (B/A-t and M/A-t).

Results: SUVmean values in dorsobasal ROIs and B/A-p ratios were increased in SSc with ILD compared with SSc without ILD (P = 0.04 and P = 0.07, respectively), SLE (P = 0.003 and P = 0.002, respectively) and pSS (P = 0.03 and P = 0.02, respectively). Increased uptake in the dorsobasal lungs and increased B/A-t ratios corresponded to both ground glass and reticulation on high resolution CT.

Conclusion: Semi-quantitative assessment of 18F-FDG PET/CT is able to distinguish ILD from non-affected lung tissue in SSc, suggesting that it may be used as a new biomarker for SSc-ILD disease activity.

Keywords: 18F-FDG PET/CT; Systemic sclerosis; interstitial lung disease; lung fibrosis; positron emission tomography.

MeSH terms

  • Adult
  • Aged
  • Case-Control Studies
  • Female
  • Fluorodeoxyglucose F18*
  • Humans
  • Lung / diagnostic imaging
  • Lung Diseases, Interstitial / diagnostic imaging*
  • Lung Diseases, Interstitial / etiology
  • Male
  • Middle Aged
  • Positron Emission Tomography Computed Tomography / methods
  • Positron Emission Tomography Computed Tomography / statistics & numerical data*
  • Positron-Emission Tomography / methods
  • Positron-Emission Tomography / statistics & numerical data*
  • Radiopharmaceuticals*
  • Retrospective Studies
  • Scleroderma, Systemic / complications
  • Scleroderma, Systemic / diagnostic imaging*
  • Sjogren's Syndrome / diagnostic imaging


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18