Sestamibi Parathyroid Scan

• It’s a nuclear scan to localize parathyroid adenomas.
• Tc99m-sestamibi is absorbed faster by a hyperfunctioning parathyroid gland
• Allows the surgeon to remove the one gland of the 4 parathyroids which is hyperfunctioning – minimally invasive parathyroidectomy.
• Sestamibi scan only detects only about 70% of HPT lesions.  So don’t discard the diagnosis of HPT when the sestamibi scan is negative.
• Hyperparathyroidism is the excess of parathyroid hormone (PTH) in the blood stream.  Primary hyperparathyroidism (Primary HPT) has lab values of high calcium and high PTH.  Secondary hyperparathyroidism has lab values of low calcium and high PTH.  Most common cause of secondary HPT is chronic renal failure.  (treatment is possibly renal transplantation).
• Sestamibi scan is to detect parathyroid hyperfunctioning which then is a cause of primary HPT.