Incidental FDG-Avid Focuses in Palatine Tonsils on PET/CT

Laryngoscope. 2022 Dec;132(12):2370-2378. doi: 10.1002/lary.30081. Epub 2022 Feb 28.

Abstract

Objectives: The management of incidental findings of FDG-avid tonsils on PET/CT (IFT) is unclear. We aimed to explore the prevalence of malignancy in IFT, identify risk factors for malignancy, and calculate optimal cutoffs of maximum standardized uptake values (SUVmax ) to discriminate between benign and malignant lesions.

Methods: All patients who were tonsillectomized at our institution because of IFT from October 2011 to December 2020 were included. Patients undergoing PET/CT due to suspected tonsillar disease or cancer of unknown primary were excluded.

Results: In total, 77 patients were included, of which 11 (14%) of them had IFT malignancy. Dysphagia (p = 0.019) and alcohol abuse (p = 0.035) were associated with malignancy. Absolute SUVmax cutoff (≥9: sensitivity 100%; specificity 53%) was superior to SUVmax side-to-side ratio (≥1.5: sensitivity 64%; specificity 70%) to discriminate between benign and malignant lesions.

Conclusion: We recommend tonsillectomy for patients with IFT displaying SUVmax ≥ 9.0, ratio ≥ 1.5, or symptoms or findings suggesting malignancy.

Level of evidence: 3 Laryngoscope, 132:2370-2378, 2022.

Keywords: FDG-PET/CT; cancer; incidental; malignancy; tonsil.

MeSH terms

  • Fluorodeoxyglucose F18
  • Humans
  • Incidental Findings
  • Palatine Tonsil / diagnostic imaging
  • Positron Emission Tomography Computed Tomography*
  • Positron-Emission Tomography
  • Radiopharmaceuticals
  • Tonsillectomy*

Substances

  • Fluorodeoxyglucose F18
  • Radiopharmaceuticals