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

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.