Incidence and Risk Factors for Brown Adipose Tissue Uptake in PET Imaging in Pediatric Patients.

Abstract

Positron emission tomography (PET) scans are used in disease diagnosis and evaluation for pediatric oncology patients. Brown adipose tissue (BAT) 18 F-fluorodeoxyglucose-PET uptake is reported in 35% to 47% of pediatric patients. Several risk factors may be associated with BAT uptake. The aim was to determine the incidence and risk factors for BAT in pediatric patients using a consensus-based system and a novel grading scale. A total of 285 PET scans in 154 patients were retrospectively reviewed for the presence of BAT from September 2015 through December 2016. A consensus review was done by 2 radiologists, who graded BAT on a 0 to 3 scale and assessed its impact on PET interpretation. The presence of moderate to severe BAT occurred in 11% of PET scans, and 6% of PETs had limited interpretation. Hodgkin lymphoma (n=53) patients had a 3.62-fold increased odds of moderate or severe BAT and a 6.59-fold increased odds of limited interpretation on PET imaging. The incidence of BAT was low but impacted radiologic interpretation when present. Further studies with a larger group of Hodgkin lymphoma patients are needed to explore the risk factors associated with moderate or severe BAT.