sup 18^F-Fluorodeoxyglucose positron emission tomography pulmonary imaging in idiopathic pulmonary fibrosis is reproducible: implications for future clinical trials

• Published in: European journal of nuclear medicine and molecular imaging Vol. 39; no. 3; p. 521
• Main Authors: Win, Thida, Lambrou, Tryphon, Hutton, Brian F, Kayani, Irfan, Screaton, Nicholas J, Porter, Joanna C, Maher, Toby M, Endozo, Raymondo, Shortman, Robert I, Lukey, Pauline, Groves, Ashley M
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.03.2012
• Subjects: Lung diseases; Metabolism; Nuclear medicine; Tomography
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-011-1986-7

Noninvasive markers of disease activity in patients with idiopathic pulmonary fibrosis (IPF) are lacking. We performed this study to investigate the reproducibility of pulmonary ^sup 18^F-FDG PET/CT in patients with IPF. The study group comprised 13 patients (11 men, 2 women; mean age 71.1±9.9 years) with IPF recruited for two thoracic ^sup 18^F-FDG PET/CT studies performed within 2 weeks of each other. All patients were diagnosed with IPF in consensus at multidisciplinary meetings as a result of typical clinical, high-resolution CT and pulmonary function test features. Three methods for evaluating pulmonary ^sup 18^F-FDG uptake were used. The maximal ^sup 18^F-FDG pulmonary uptake (SUVmax) in the lungs was determined using manual region-of-interest placement. An ^sup 18^F-FDG uptake intensity histogram was automatically constructed from segmented lungs to evaluate the distribution of SUVs. Finally, mean SUV was determined for volumes-of-interest in pulmonary regions with interstitial lung changes identified on CT scans. Processing included correction for tissue fraction effects. Bland-Altman analysis was performed and interclass correlation coefficients (ICC) were determined to assess the reproducibility between the first and second PET scans, as well as the level of intraobserver and interobserver agreement. The mean time between the two scans was 6.3±4.3 days. The interscan ICCs for pulmonary SUVmax analysis and mean SUV corrected for tissue fraction effects were 0.90 and 0.91, respectively. Intensity histograms were different in only 1 of the 13 paired studies. Intraobserver agreement was also excellent (0.80 and 0.85, respectively). Some bias was observed between observers, suggesting that serial studies would benefit from analysis by the same observer. This study demonstrated that there is excellent short-term reproducibility in pulmonary ^sup 18^F-FDG uptake in patients with IPF.[PUBLICATION ABSTRACT]