RESUMO
OBJECTIVE: The objective of our study was to determine whether the depiction of brown adipose tissue (BAT) in PET/CT studies of pediatric patients with lymphoma is related to disease status. MATERIALS AND METHODS: The PET/CT studies of 31 pediatric patients (17 boys and 14 girls) with Hodgkin or non-Hodgkin lymphoma were reviewed, and the prevalence of metabolically active BAT at diagnosis and the prevalence of BAT when there was no evidence of disease were compared. RESULTS: The percentage of PET/CT studies depicting BAT was greater when there was no evidence of disease than at diagnosis (10% vs 77%, respectively; p < 0.001). The McNemar test indicated a strong inverse correlation between the presence of disease and the presence of BAT (p < 0.001). This correlation was noted when all subjects were examined together and when subjects with Hodgkin lymphoma and those with non-Hodgkin lymphoma were analyzed separately (p < 0.001 and < 0.05, respectively). When baseline and follow-up PET/CT scans for all patients were analyzed for the presence of BAT using conditional logistic regression, both the season when the study was performed and disease status independently predicted BAT: The winter months positively predicted BAT and the presence of lymphoma was negatively correlated with the depiction of BAT on PET/CT. Age, sex, treatment, and weight did not provide additional information when added to the model. CONCLUSION: The knowledge that BAT is a predictor of disease status should contribute to the correct analysis of PET/CT studies in children with lymphoma.