¹⁸F-FDG Uptake in Less Affected Lung Field Provides Prognostic Stratification in Patients with Interstitial Lung Disease

Abstract

This study evaluated the clinical significance of 18 F-FDG PET/CT in patients with interstitial lung disease (ILD), by investigating the relationships between 18 F-FDG PET/CT parameters and clinical indicators and by evaluating the prognostic implications of 18 F-FDG PET/CT results. Methods: Ninety patients (51 men, 39 women; mean age, 55.4 y; age range, 26-78 y) with ILD who underwent 18 F-FDG PET/CT were retrospectively analyzed. SUV mean was defined as the mean SUV of the less-affected lung field, SUV TF as adjusted SUV mean using tissue fraction (TF), and CT mean as the mean attenuation of the corresponding region of interest on highresolution CT. SUV mean , SUV TF , and CT mean were compared in the 90 ILD patients and in 15 age-and sex-matched controls. Correlations of SUV max , SUV mean , SUV TF , and CT mean with clinical indicators, including estimated percentage of forced vital capacity (%FVC), estimated percentage of diffusion capacity of the lungs for carbon monoxide (%DLco), sialylated carbohydrate antigen Krebs von den Lungen-6 (KL-6), surfactant protein D (SP-D), C-reactive protein (CRP), lactate dehydrogenase (LDH), and ILD-sex-agephysiology (GAP) index, were evaluated using the Spearman rank correlation test and the Tukey-Kramer test. A Cox proportional hazards model was used for univariate and multivariate analyses of factors associated with lung transplantation-free survival. Results: SUV mean , SUV TF , and CT mean were significantly higher in ILD patients than in healthy controls, except for CT mean in patients with a nonusual interstitial pneumonia pattern. SUV mean and CT mean were significantly correlated with %FVC, %DLco, KL-6, and SP-D; SUV TF was significantly correlated with %DLco, KL-6, SP-D, and LDH; and SUV max was weakly correlated with KL-6 and CRP. Univariate analysis showed that SUV mean , SUV TF , sex, %FVC, %DLco, KL-6, and ILD-GAP index were significantly prognostic of lung transplantationfree survival; and multivariate analysis showed that SUV mean and ILD-GAP index were independently prognostic of lung transplantationfree survival. A higher SUV mean indicated a poorer prognosis, especially in patients with moderate risk based on ILD-GAP index. Conclusion: SUV mean was significantly but moderately correlated with clinical indicators, providing independent prognostic information in patients with ILD. 18 F-FDG PET/CT may be helpful for monitoring and risk stratification of ILD patients.

18F-FDG accumulation in less-affected lung area predicts postoperative interstitial lung disease acute exacerbation in lung cancer: A case control study

“…As in previously reports (18,19), both SUV mean and SUV TF in the less-affected lung fields of NSCLC patients with ILD were significantly higher than in those patients without ILD. These results suggest that accumulation of 18 F-FDG in less-affected lung fields may reflect inflammatory conditions in the pulmonary interstitium, which cannot be visually detected with conventional HRCT.…”

“…All patients underwent enhanced or un-enhanced chest HRCT by 64-row helical mode using 320-row multidetector CT scanners (Aquilion ONE, Canon Medical Systems, Otawara, Tochigi, Japan) or 16-row helical scan mode (Sensation Cardiac, Siemens, Munich, Germany) within 3 months after 18 as the highest SUV in ILD lesion (18,19). SUV tissue fraction (TF) was analyzed to adjust for metabolic condition, regardless of differences in the degree of region-based aeration (26,27).…”

Assessment of 18F-FDG uptake in idiopathic pulmonary fibrosis: influence of lung density changes

“…The aim of this study was to evaluate the prognostic value of [18F]-FDG PET/CT in IPF patients. Contrary to previous studies evaluating the usefulness of [18F]-FDG PET/CT in IPF (Meissner et al, 2006;Lee et al, 2014;Justet et al, 2017;Umeda et al, 2015;Win et al, 2018;Nobashi et al, 2016), SUV and derived parameters were corrected for lung density in the present study. We hypothesized that correction for lung density is important since lung density increases with the development of fibrotic tissue, leading to reduced lung volumes and to higher tissue/air ratios compared to normal lung.…”

Absence of early metabolic response assessed by 18F-FDG PET-CT after initiation of antifibrotic drugs in IPF patients.

“…Value of metabolic evaluation by [18F]-FDG PET/CT has been studied in IPF patients [4][5][6][7][8][9]. An increased in lung uptake of [18F]-FDG is present in IPF lungs [4,5] and SUV and other derived parameters have some prognostic value in these patients [6][7][8][9]. Two antifibrotics are currently available for the treatment of IPF patients, pirfenidone and nintedanib, which were approved in Europe in 2011 and 2015, respectively [16,17].…”

“…An increase in lung uptake of [18F]-FDG was observed in areas of reticular/honeycombing and ground-glass opacity on high-resolution CT (HRCT) [4] as well as in areas of normal pulmonary parenchyma [5]. Recent studies have also evaluated the prognostic value of the standardized uptake value (SUV) and other derived parameters in IPF patients [6][7][8][9]. Moreover Justet and colleagues demonstrated that SUVmean and SUVmax were correlated with the severity of the lung involvement as measured by a decline in forced vital capacity (FVC) and lung diffusion capacity for carbon monoxide (DLCO) and increased GAP score [8].…”