Idiopathic Pulmonary Fibrosis and Diffuse Parenchymal Lung Disease: Implications from Initial Experience with¹⁸F-FDG PET/CT

Abstract

The purpose of this study was to evaluate integrated 18 F-FDG PET/CT in patients with idiopathic pulmonary fibrosis (IPF) and diffuse parenchymal lung disease (DPLD). Methods: Thirty-six consecutive patients (31 men and 5 women; mean age 6 SD, 68.7 6 9.4 y) with IPF (n 5 18) or other forms of DPLD (n 5 18) were recruited for PET/CT and high-resolution CT (HRCT), acquired on the same instrument. The maximal pulmonary 18 F-FDG metabolism was measured as a standardized uptake value (SUV max ). At this site, the predominant lung parenchyma HRCT pattern was defined for each patient: ground-glass or reticulation/honeycombing. Patients underwent a global health assessment and pulmonary function tests. Results: Raised pulmonary 18 F-FDG metabolism in 36 of 36 patients was observed. The parenchymal pattern on HRCT at the site of maximal 18 F-FDG metabolism was predominantly ground-glass (7/36), reticulation/ honeycombing (26/36), and mixed (3/36). The mean SUV max in patients with ground-glass and mixed patterns was 2.0 6 0.4, and in reticulation/honeycombing it was 3.0 6 1.0 (MannWhitney U test, P 5 0.007). The mean SUV max in patients with IPF was 2.9 6 1.1, and in other DPLD it was 2.7 6 0.9 (MannWhitney U test, P 5 0.862). The mean mediastinal lymph node SUV max (2.7 6 1.3) correlated with pulmonary SUV max (r 5 0.63, P , 0.001). Pulmonary 18 F-FDG uptake correlated with the global health score (r 5 0.50, P 5 0.004), forced vital capacity (r 5 0.41, P 5 0.014), and transfer factor (r 5 0.37, P 5 0.042). Conclusion: Increased pulmonary 18 F-FDG metabolism in all patients with IPF and other forms of DPLD was observed. Pulmonary 18 F-FDG uptake predicts measurements of health and lung physiology in these patients. 18 F-FDG metabolism was higher when the site of maximal uptake corresponded to areas of reticulation/honeycomb on HRCT than to those with ground-glass patterns.

Ionizing radiation induces myofibroblast differentiation via lactate dehydrogenase

“…with high-resolution positron emission tomography/computerized tomography, indicating that areas of fibrosis have increased glucose uptake (12). Increased glucose uptake can contribute to accelerated growth and proliferation, a characteristic that is also consistent with fibroblasts from fibrotic lung tissue (16,29).…”

Preclinical SPECT/CT Imaging of αvβ6 Integrins for Molecular Stratification of Idiopathic Pulmonary Fibrosis

“…The 111 In-DTPA-A20FMDV2 is known to bind to human avb6 integrins in vitro and in vivo (30,31) and 111 In-labeled peptides are widely used in clinical practice. Moreover, 18 F-A20FMDV2 has been used in vivo for successful PET imaging of avb6 on human xenografts (30), and PET/CT scans have previously been obtained for IPF patients (22,23). Thus, SPECT/CT or PET/CT with radiolabeled A20FMDV2 can offer valuable new imaging modalities for stratifying patients with IPF, although at the present time SPECT is more widely available and less costly than PET imaging.…”

“…Initial studies have used PET tracers including 18 F-FDG and 68 Ga-labeled somatostatin analogs that bind the somatostatin receptor (21,22). Pulmonary uptake of both these radiotracers is increased in IPF patients, and lung 18 F-FDG levels have been related to disease severity (23). Although there are some preclinical data demonstrating a role for somatostatin receptors in IPF (24), neither of these tracers targets well-validated pathways implicated in IPF.…”

Cancer cells metabolically "fertilize" the tumor microenvironment with hydrogen peroxide, driving the Warburg effect

“…[14][15][16][17][18][19][20][21] Here, we show that cancer-associated fibroblasts have the largest increases in glucose uptake, secondary to mitochondrial dysfunction. Thus, PET scanning with 2-[…”

“…[14][15][16][17][18][19][20][21] Similarly, PET is also now used to detect inflammation 78 that is due to both infectious diseases, such as fever of unknown origin (FUO) and bacteremic foci, [79][80][81] and non-infectious diseases, such as graft rejection in liver and renal transplants. [82][83][84][85] We have recently shown that inflammatory cytokines induce autophagy in cancer-associated fibroblasts, consistent with a shift toward aerobic glycolysis under inflammatory conditions.…”