Beware of False-Positive FDG PET/CT Interpretations for Presacral Recurrent Rectal Cancer

Clin Nucl Med. 2019 May;44(5):e342-e344. doi: 10.1097/RLU.0000000000002545.

Abstract

FDG PET/CT is considered an accurate method for the detection of recurrent rectal cancer in the pelvis. Excess presacral soft tissue is found in up to half of patients after (chemo)radiation and surgery for rectal cancer, and usually represents fibrosis that is metabolically inactive. However, presacral soft tissue that is FDG avid is generally considered suspicious for recurrent cancer. Nevertheless, FDG avidity in the presacral space not uncommonly proves to be due to benign inflammatory changes, and additional MRI may be diagnostically useful, as demonstrated in the presented 2 cases.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • False Positive Reactions
  • Fluorodeoxyglucose F18
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / diagnostic imaging*
  • Positron Emission Tomography Computed Tomography*
  • Radiopharmaceuticals
  • Rectal Neoplasms / diagnosis
  • Rectal Neoplasms / diagnostic imaging*

Substances

  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18