Image fusion analysis of 99m Tc-HYNIC-octreotide scintigraphy and CT/MRI in patients with thyroid-associated orbitopathy: the importance of the lacrimal gland

Eur J Nucl Med Mol Imaging. 2003 Aug;30(8):1155-9. doi: 10.1007/s00259-003-1207-0. Epub 2003 Jun 13.

Abstract

The aim of this study was to describe the anatomical structures that show uptake of the somatostatin analogue octreotide in patients with thyroid-associated orbitopathy (TAO). The study population comprised a series of 20 TAO patients attending the out-patient thyroid clinic and 12 patients presenting head or neck tumours. Scintigraphy was carried out with our newly developed tracer, technetium-99m labelled EDDA-HYNIC-TOC ((99m)Tc-TOC). Morphological imaging was done with either magnetic resonance imaging or X-ray computed tomography without contrast medium. Both imaging procedures were done within an interval of 3-4 weeks. For the image fusion procedure, specific external reference markers were used for each imaging modality. The markers were screwed onto a reference frame, which was held in place via a vacuum-fixed mouthpiece. The anatomical structure showing tracer uptake that was most frequently recognised was the lacrimal gland, followed by the retronasal area, cervical lymph structures, salivary glands, the anterior insertion points of the extra-ocular muscles and discrete areas of the neck extensor muscles. The lacrimal gland and the retronasal area showed the highest and most frequent uptake of (99m)Tc-TOC in TAO patients, whereas such uptake did not occur in the retrobulbar space. In spite of knowledge of these results of image fusion, no changes in the involved structures could be detected on morphological imaging. It is concluded that binding of (99m)Tc-TOC is more frequently localised to the anterior compartment of the eye and to the neck. The previously used term "orbital" uptake should be abandoned and replaced by a descriptive term relating to the anatomically recognised structure showing tracer accumulation, i.e. the lacrimal gland. The uptake of octreotide by lymphoid and salivary glands opens a new field of investigation related to the physiology of somatostatin.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Validation Study

MeSH terms

  • Algorithms*
  • Graves Disease / diagnosis
  • Graves Disease / diagnostic imaging*
  • Graves Disease / metabolism
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Lacrimal Apparatus / diagnostic imaging*
  • Lacrimal Apparatus / metabolism
  • Lymph Nodes / diagnostic imaging
  • Lymph Nodes / metabolism
  • Magnetic Resonance Imaging / methods
  • Nasal Cavity / diagnostic imaging
  • Nasal Cavity / metabolism
  • Neck
  • Octreotide / analogs & derivatives*
  • Octreotide / pharmacokinetics*
  • Orbital Diseases
  • Organotechnetium Compounds / pharmacokinetics*
  • Radionuclide Imaging
  • Radiopharmaceuticals / pharmacokinetics
  • Salivary Glands / diagnostic imaging
  • Salivary Glands / metabolism
  • Subtraction Technique*
  • Tissue Distribution
  • Tomography, X-Ray Computed / methods

Substances

  • Organotechnetium Compounds
  • Radiopharmaceuticals
  • technetium Tc 99m hydrazinonicotinyl-Tyr(3)-octreotide
  • Octreotide