SPECT/CT in hyperparathyroidism

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.