SPECT/CT in hyperparathyroidism

Abstract

Hybrid SPECT/CT imaging is playing an increasingly important role in nuclear medicine in several oncological and non-oncological fields. This review presents a literature survey on the use of SPECT/CT as an adjunct to parathyroid scintigraphy in patients with hyperparathyroidism (HPT), highlighting the certainties and the controversies that have so far emerged in this regard. SPECT/CT, providing both functional and anatomical data, has proved to be superior to conventional planar parathyroid scintigraphy and to SPECT for the precise localization and characterization of areas of marked uptake of radiotracers (MIBI or tetrofosmin) corresponding to abnormal parathyroid glands, thus facilitating their surgical treatment. The major benefits of SPECT/CT have been observed in patients with ectopic adenomas, mainly in the mediastinum, and in those with previous neck surgery. In some studies, SPECT/ CT has also demonstrated a higher sensitivity than conventional planar or SPECT scans particularly in the detection of low-weight parathyroid adenomas and in the presence of concomitant nodular goiter. In other studies, SPECT/CT has also been found to be more specific, with the anatomical data provided by the CT component shown to be of help in correctly categorizing MIBI-avid non-parathyroid lesions. No definitive conclusions on the clinical value of SPECT/CT in patients with secondary HPT and multiglandular disease can be done due to the small number of studies thus far conducted, but the current available data nevertheless seem to suggest that hybrid imaging is able to detect a significantly higher number of hyperplastic glands than planar scanning can.

The role of combined techniques of scintigraphy and SPECT/CT in the diagnosis of primary hyperparathyroidism

“…These disadvantages consist of the fast clearance of Techentium sestamibi and low sensitivity for localizing parathyroid lesions or differentiating thyroid nodules from parathyroid lesions. [7] A negative parathyroid scan does not exclude the diagnosis of hyperparathyroidism. [1,5,9]…”

“…Case reports of combined imaging techniques were first reported in the early 2000s, localizing ectopic mediastinal parathyroid adenomas, leading to a minimally-invasive surgical approach. [7,10]…”

“…The addition of CT to SPECT allows precise topographic detection of the lesions, including the relations to the thyroid, trachea, esophagus, muscles, and blood vessels. [7]…”

New scintigraphic methods for parathyroid imaging

“…Pre-operative imaging consists of a combination of planar scintigraphy with parallel-hole or pinhole collimator scintigraphy with single (or dual) isotope dynamic 99m Tc-sestamibi(/ 99m TcO 4 ) scintigraphy with SPECT/CT and ultrasonography, which provide up to now the best accuracy and is critical for successful minimal invasive surgery aiming to lower morbidity and complication rate [1][2][3][4][5]. Lately, there have been advances in nuclear medicine methods for parathyroid imaging, which will focus thereafter on:…”

“…Jusqu'à maintenant, l'imagerie préopératoire par scintigraphie dynamique avec collimateurs à trous parallèles ou pinhole sur simple ou double isotope 9m Tc-sestamibi(/ 99m TcO4) avec tomographie par émission monophotonique couplée à la tomodensitométrie (TEMP/TDM) en combinaison avec l'échographie fournissaient la meilleure approche et permettaient de diminuer le taux de complications et de morbidités dans la chirurgie minimale invasive [1][2][3][4][5]. Récemment, certains progrès ont eu lieu en médecine nucléaire pour l'imagerie des glandes parathyroïdes, selon les méthodes détaillées ci-après et qui peuvent être divisées en :…”