18F-FDG positron emission tomography scanning in systemic sclerosis-associated interstitial lung disease: a pilot study

Arsène Mékinian,Noémie Le Gouellec,Vincent Sobanski,Martine Remy-Jardin,Eric Hachulla,Emmanuel Ledoult,Michael Soussan,Maxime Morelle,David Launay,Hélène Béhal,Damien Huglo,Clio Baillet

doi:10.1186/s13075-021-02460-8

Abstract

BackgroundInterstitial lung disease is a common complication of systemic sclerosis (SSc-ILD), and it remains difficult to accurately predict its course. Progressing ILD could be more metabolically active, suggesting that the 18F-FDG tracer could be a tool in the managing of SSc-ILD.MethodsIn our center, SSc patients and controls (non-Hodgkin lymphoma cured after first-line regimen) who had received a PET/CT were screened retrospectively. The FDG uptake (visual intensity, pattern, SUVmax) was systematically recorded in > 30 regions of interest (ROIs) linked to SSc in a blind reviewing by 2 independent nuclear medicine physicians using a standardized form.ResultsAmong the 545 SSc patients followed up in our center, 36, including 22 SSc-ILDs, had a PET/CT, whose indication was cancer screening in most cases. The mean ± SD age was 57.9 ± 13.0 years with 20/36 females. Fourteen patients had a disease duration of less than 2 years. A third had anti-centromere antibodies and 27.8% had anti-topoisomerase antibodies. Pulmonary FDG uptakes were higher in SSc patients than in controls (n = 89), especially in those with ILD compared with those without ILD. Pulmonary FDG uptakes were positively correlated with the ILD severity (fibrosis extent, %FVC, and %DLCO). No significant difference was found in the FDG uptakes from extrathoracic ROIs. Progressing SSc-ILDs within the 2 years after PET/CT (n = 9) had significant higher pulmonary FDG uptakes at baseline than stable SSc-ILDs (n = 13).ConclusionPET/CT could be a useful tool in the assessment of the severity and the prediction of pulmonary function outcome of SSc-ILD.

Highlights

Interstitial lung disease is a common complication of systemic sclerosis (SSc-ILD), and it remains difficult to accurately predict its course
The initiation of immunosuppressants for SScILD is usually recommended and more efficient in patients with active and/or progressing ILD, currently evaluated by the extension observed in high-resolution computed scans (HRCTs) and the deterioration in pulmonary function tests (PFTs; i.e., forced vital capacity [Forced vital capacity (FVC)] and diffusing capacity for the lung of carbon monoxide [DLCO]) [12]
We provided a detailed description of Positron emission tomography (PET)/CT findings, and they support that this tool could be useful in SSc, especially in SSc-ILD

Summary

Introduction

Interstitial lung disease is a common complication of systemic sclerosis (SSc-ILD), and it remains difficult to accurately predict its course. Interstitial lung disease (ILD) is a frequent complication in systemic sclerosis (SSc) [1, 2]. It is the first cause of death attributable to SSc [3, 4]. Managing SSc-ILD is challenging because of the great heterogeneity of its courses, which can be stable or slowly or quickly deteriorating [6,7,8], and the modest benefit of immunosuppressants [9,10,11,12]. Tools and biomarkers must be developed to assess ILD activity and the predictors of ILD progression and treatment response to optimize the decision-making [18, 19] in an era where, beyond immunosuppressants, new antifibrotic treatments, for example, nintedanib, are or will be available [20]

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Results

Conclusion