Parathyroid Scintigraphy - European Association of Nuclear Medicine

Table 1. Steps in minimally invasive radioguided surgery (MIRS) of parathyroid adenomas using
the low 99m Tc-sestamibi dose protocol developed in our centre
Blood samples are drawn from a peripheral vein both before commencing surgery and 10 min
following the removal of the parathyroid adenoma to measure intra-operative QPTH levels
37 MBq of 99m Tc-sestamibi is injected in the operating theatre 10 min before the start of
surgery
Prior to surgical incision, the patient’s neck is scanned with an 11-mm collimated probe to
localise the site with the highest count rate, corresponding to the cutaneous projection of
the parathyroid adenoma
A transverse midline neck access (approximately 1 cm above the sternal notch) is preferred
because conversion to BNE is easily obtained if necessary
An 11-mm collimated probe is repeatedly inserted through a 2-cm skin incision, guiding the
surgeon to the maximum count rate area corresponding to the parathyroid adenoma
In some patients with a parathyroid adenoma located deep in the neck, ligature of the middle
thyroid vein and of the inferior thyroid artery is required
Radioactivity of the parathyroid adenoma, thyroid gland and background is measured with
the probe
Radioactivity is measured ex vivo to confirm successful removal of parathyroid tissue
Radioactivity of the empty operation site is checked to evaluate the completeness of parathyroid
tissue removal
Tissue ratios are calculated (P/B, P/T etc.)
QPTH, quick parathyroid hormone; BNE, bilateral neck exploration; P/B, parathyroid to background
ratio; P/T, parathyroid to thyroid ratio