Orbital Metastasis: A Rare but Typical Location of Small Intestine Neuroendocrine Tumor on 18F-FDOPA PET/CT

Clin Nucl Med. 2022 Aug 1;47(8):717-718. doi: 10.1097/RLU.0000000000004137. Epub 2022 Mar 30.

Abstract

Orbital foci of increased uptake are sometimes visualized on 18F-FDOPA PET/CT, but the literature remains poor as to their nature. The orbit is indeed a rare site of metastatic involvement. Given this low probability of metastatic location, the question of an incidental benign finding may arise. We reviewed all 18F-FDOPA PET/CT examinations performed at our institution between January 2015 and May 2021: 4/149 patients presented at least 1 orbital focus of increased uptake, all of them presented a metastatic small intestine neuroendocrine tumor. Somatostatin receptor expression was confirmed using 68Ga-DOTATOC PET/CT supporting the hypothesis of genuine metastases.

MeSH terms

  • Dihydroxyphenylalanine / analogs & derivatives
  • Humans
  • Intestinal Neoplasms* / diagnostic imaging
  • Intestine, Small / diagnostic imaging
  • Intestine, Small / pathology
  • Neuroendocrine Tumors* / diagnostic imaging
  • Neuroendocrine Tumors* / pathology
  • Positron Emission Tomography Computed Tomography

Substances

  • fluorodopa F 18
  • Dihydroxyphenylalanine