Effect of Propranolol on 18F-Fluorodeoxyglucose Uptake in Brown Adipose Tissue in Children and Young Adults with Neoplastic Diseases.

Abstract

To evaluate the effectiveness of propranolol at mitigating FDG uptake in brown adipose tissue (BAT) of pediatric patients with known or suspected malignancies. PET/CT scans of 3 cohorts of patients treated from 2005 to 2017 were scored for the presence of FDG uptake by BAT at 7 sites: right or left neck/supraclavicular area, right or left axilla, mediastinum, posterior thorax, and abdomen/pelvis. Uptake was scored as follows: 0, none; 1, mild uptake < liver; 2, moderate uptake = liver; and 3, intense uptake > liver. Group 1 consisted of 323 patients (630 scans) who had no specific preparation to mitigate FDG uptake by BAT. Group 2 consisted of 345 patients (705 scans) who underwent only warming in an uptake room with a fixed temperature at 24°C. Group 3 consisted of 622 patients (1457 scans) who underwent warming. In group 3, patients 8years and older, 471 patients (1114 scans), were also pre-medicated with oral propranolol 60min before injection of FDG. Generalized estimation equation, using the logit link method, was used to model the relationship between the incidence of BAT score > 0, in any site, as a function of age, sex, seasonal effect, and body surface area (BSA). In patients aged 8years or older, the incidence of BAT uptake was 35-44% and declined to 15% with propranolol. BAT was most frequent in the neck (26%), axilla (18%), posterior thorax (18%), mediastinum (14%), and abdomen/pelvis (8%); BAT was less common in warm months (p = 0.001). No substantial benefit was shown with pre-injection warming alone. No significant effect was found for age, sex, or BSA separately. When BAT uptake was present, it was usually intense. Propranolol preparation minimizes FDG uptake by BAT and should be considered routine for pediatric FDG PET/CT cancer-related protocols in children, adolescents, and young adults.