J Nucl Med. 2007; 48 (Supplement 2):291P
General Clinical Specialties: Pulmonary
Mean standardized uptake values (SUV) by normal lung and liver tissue: A quantitative 18F-FDG PET study in relation to age
1 Nuclear Medicine, SUNY Buffalo, Buffalo, New York
Objectives: To help establish normal reference values for PET oncology studies of the thorax and abdomen, this retrospective study was undertaken to define normal SUVs for both liver and lung tissue, with attention given to the age of the patient. Although FDG uptake in breast tissue has been studied in relation to age, there have been no known studies to examine if FDG uptake within normal lung or liver varied with age in relation to age of the patient. Methods: Retrospective analysis of hand drawn region of interest measurements taken from the lower and mid lung fields in the axial plane were studied in relation to age for 109 cases (injected FDG dose:370 MBq; scanner : Positron HZL ) Mean SUV for the lung were plotted in relation to age in years; right and left lung SUV values were averaged to generate one value per patient per study. Liver mean SUV measurements were taken from normal appearing right lobe of the liver in 139 cases, and graphed in relation to age. Results: The average mean SUV from normal lung tissue was 0.45 (n=109) with no significant correlation to age found in this group where most patients were between 40 and 85 years. A weighted average calculation including the data from two previously published studies from other labs show the average mean SUV of normal lung parenchyma to be 0.52 (n=279). In contrast to the lung parenchyma, normal appearing liver had a higher and more heterogeneous pattern of uptake with the average mean SUV equaling 1.55 (n=139). Normal lung to normal liver mean SUV values averaged 0.27 (n=99). No significant correlation was seen between age age and normal liver FDG uptake was noted. When including the mean liver SUVs from three other published cases from different labs, a weighted average for normal liver SUV was found to be 2.16 for an aggregate total of 389 cases. Conclusions: Between the ages of 40 and 85, no definite correlation between age and normal FDG uptake was seen within the liver or lung, where mean SUVs measured 1.55 and 0.45 respectively. More research is needed on age related changes for FDG uptake at all ages in other organs, as this not only helps establish normative values for age appropriate PET scan interpretation but also may give some insight into the biology of aging.