Radio-guided Parathyreoidektomie: Erfolgreiche intraoperative Lokalisationsdiagnostik bei primärem und rezidivierendem Hyperparathyreoidismus mit 99 mTc-MIBI

Abstract

The intraoperative use of a gamma probe detector is highly effective in identifying parathyroid adenomas in pHPT and recurrent HPT and supports minimally invasive techniques.

High cardiac background activity limits 99mTc-MIBI radioguided surgery in aortopulmonary window parathyroid adenomas

“…Numerous application protocols regarding RGS have been reported, with injected radioactivity ranging from 37 to 740 MBq 99m Tc-MIBI. Concerning the time interval between application and scanning, protocols are rather similar with tracer injection around the start of surgery, which usually results in an interval of about 30 to 90 minutes [1-4,22]. Administration of 370 MBq is probably most common [2,4].…”

“…Concerning the time interval between application and scanning, protocols are rather similar with tracer injection around the start of surgery, which usually results in an interval of about 30 to 90 minutes [1-4,22]. Administration of 370 MBq is probably most common [2,4]. This protocol seems to be the best compromise regarding detection accuracy and radiation protection of the personnel.…”

“…Most of the protocols in the neck are using a 20% cut-off. Based on that criterion, surgery is considered successful when radioactivity of the removed specimen is more than 20% higher than that of the surrounding (thyroid) tissue [4,13,14]. …”

“…in the mediastinum) [1-4]. Potential benefits of RGS are (a) better identification of pathological parathyroid tissue by intraoperative detection of regions with highest tracer uptake and (b) control of cure by comparison of the ex vivo radioactivity over the removed tissue and in vivo activity within the resection area [5-7].…”

“…99m Tc-MIBI, a tracer that was originally developed for myocardial scintigraphy, has however physiological uptake in the myocardium as well as uptake in many thyroid nodules including thyroid cancer [9,11]. For reliable discrimination in cervical PHPT surgery, a ratio between thyroid tissue and parathyroid adenoma of at least 1:1.3-1.5 has been suggested [4,12,13]. After removal of the parathyroid adenoma, an ex vivo radioactivity counting rate over the adenoma of more than 20% compared to the thyroid background [4,13,14] and the surgical bed is considered to be a credible criterion for successful excision [13].…”