On a Technetium 99 Sestamibi nuclear scan, a radioactive marker is placed in the sternal notch. The distance between the marker and the parathyroid adenoma is measured on the scan and the skin is marked accordingly. This method is not very accurate, however, it gives the surgeon a good estimate of the location of the adenoma with respect to the sternal notch or the clavicular head. It is particularly useful for the removal of superior parathyroids.