What is Minimally invasive radio guided parathyroidectomy ?
Minimally invasive radio guided parathyroidectomy (MIRP) is a second alternative to conventional parathyroidectomy and involves 99m technetium sestamibi scanning the morning of the surgery. An incision is made; either a unilateral or a bilateral neck exploration is performed; and abnormal parathyroid(s) are removed. A small, hand-held gamma probe is then used to measure the ex vivo radioactive counts of the excised parathyroid to determine whether the gland is hyperfunctioning. If the radioactive counts of the excised parathyroid are ≧ 20% higher than the counts in the operative bed, then the gland is presumed to be an adenoma. Contrary to common perception, the gamma probe is not typically used to localize the abnormal parathyroid. This is because the thyroid gland also takes up sestamibi, so the high radioactive counts of the thyroid obscure the ability to use the probe to discern the location of the parathyroid. Although this technique can be useful in confirming that an excised parathyroid is hyperfunctioning, it does not rule out the possibility of additional hyperfunctioning glands. Either all four parathyroids must be evaluated or an ioPTH assay should be used to exclude the possibility of multiglandular disease (15%).