Low-dose oral propranolol could reduce brown adipose tissue F-18 FDG uptake in patients undergoing PET scans

Clin Nucl Med. 2007 May;32(5):351-7. doi: 10.1097/01.rlu.0000259570.69163.04.


Fluorine-18 fluoro-2-deoxy-D-glucose (FDG) uptake in brown adipose tissue (BAT) may generate FDG-PET scan misinterpretation. Recent studies have shown reduced FDG uptake in BAT in rats treated with high doses of the beta-blocker propranolol. The aim of this observational study was to present a cohort of patients with high FDG uptake in BAT who underwent a second scan after receiving a low dose of propranolol, to determine whether the use of this premedication could improve the diagnostic confidence of FDG-PET scans by inhibition FDG uptake in BAT, and also whether administration of this drug affects tracer uptake in tumors.

Methods: Twenty-six cancer patients, presenting with increased BAT FDG uptake, were selected prospectively. On a different day, patients were given propranolol 20 mg orally 60 minutes prior to FDG administration 185-277.5 MBq (5-7.5 mCi) and were scanned again. Basal and postpropranolol BAT SUVmax, and tumor SUVmax (when present) were measured.

Results: Mean basal BAT SUVmax was 5.52+/-2.3. Mean postpropranolol SUVmax was 1.39+/-0.42 (P<0.0001). In 11 patients, the basal mean tumor SUVmax was 8.07+/-6.4, and 7.88+/-5.9 in postpropranolol scans (P=0.53). Nine patients showed mediastinal FDG uptake in the basal scan, affecting image interpretation. This was not observed in postpropranolol scans. No adverse effects due to propranolol were encountered.

Conclusions: In this patient cohort, there was significant reduction of FDG uptake in BAT following propranolol administration, allowing for adequate interpretation of FDG-PET and software-fused FDG-PET with CT images, particularly in the mediastinal area, without affecting tumor tracer uptake.

MeSH terms

  • Adipose Tissue / drug effects*
  • Adipose Tissue / pathology*
  • Administration, Oral
  • Adolescent
  • Adrenergic beta-Antagonists / administration & dosage*
  • Adult
  • Cohort Studies
  • Drug Interactions*
  • Female
  • Fluorodeoxyglucose F18 / pharmacokinetics*
  • Humans
  • Male
  • Middle Aged
  • Neoplasms / diagnostic imaging
  • Neoplasms / drug therapy*
  • Neoplasms / pathology*
  • Positron-Emission Tomography / instrumentation*
  • Positron-Emission Tomography / methods*
  • Propranolol / administration & dosage*


  • Adrenergic beta-Antagonists
  • Fluorodeoxyglucose F18
  • Propranolol