Konventionelle nuklearmedizinische Bildgebung bei Hyperparathyreoidismus

Abstract

For the assessment of hyperparathyroidism besides cervical ultrasound, 99 mTc-Sestamibi (MIBI) imaging is being used on a routine basis in nuclear medicine practice. MIBI is a positively charged complex, which is bound in mitochondria rich parathyroidal tissue and shows a reduced washout as compared to normal thyroid tissue. This characteristic is used during dual-phase imaging by acquiring early and late images. In order to better localize adenomas, especially if they are ectopic, it is helpful to combine planar imaging with cross-sectional (-hybrid) imaging using SPECT or SPECT/CT. With this approach, in combination with ultrasound the sensitivity for adenomas is known to be over 80 % up to 100 %. For multiglandular involvement or hyperplasia, a significantly lower detection rate is known, which, however, can be improved by a combination of planar and tomografic imaging. To what extend medication can influence the results of MIBI imaging is not well known. Glucocorticoids and calcium channel antagonist might have a negative influence on the uptake of MIBI. Another potential influencing factor could be the presence of P-glykoprotein in some adenomas, leading to a faster efflux of MIBI out of the adenoma cells and consecutively a lower detection rate.