A sestamibi scan is a nuclear medicine procedure done for patients with disorders of the parathyroid glands. It is not a diagnostic study or a confirmatory test for the presence of hyperparathyroidism. It is rather done to distinguish or localize the affected gland in a patient already diagnosed with the disease.
Parathyroid glands are four small glands located in the neck and behind the thyroid gland. These glands regulate the level of calcium in the blood for the proper functioning of muscles and nerves. The parathyroid glands normally monitor the amount of calcium circulating in the blood and when the calcium level goes down, the glands release the parathyroid hormones (PTH), which stimulate the bones to produce more calcium.
Hyperparathyroidism is the major disease affecting these glands. It causes over activity of the glands, often resulting in increased blood calcium level. This is mostly due to the presence of a tumor or cancer in one or more of the glands. Symptoms usually present as fatigue, osteoporosis or weakening of the bones, bone pain, irritability, and depression. Affected individuals may also manifest with decrease sexual drive, recurrent headaches, high blood pressure, and kidney stones.
Endocrinologists are doctors who treat patients with hormone imbalances. They frequently diagnose patients with hyperparathyroidism by doing a thorough physical examination, and with the aid of blood tests and other diagnostic procedures. Treatment may include the use of medications and sometimes, surgery for the removal of the affected gland. When removal of the gland is needed, a sestamibi scan is usually performed before the surgery in order to determine the location of the diseased parathyroid gland.
It generally takes less than three hours to do the sestamibi scan procedure. Twenty minutes prior to the procedure, a patient is sometimes given lemon juice in order to decrease saliva production. During the procedure, a radioactive dye called technecium99 (Tc-99) is injected into the vein of the patient. An overactive parathyroid gland often absorbs this dye, and this can be seen in the images taken during the procedure. Surgeons, doctors who perform operations, can then set a schedule for the removal of the affected gland by using a minimally invasive procedure.
The sestamibi scan is a relatively safe and accurate procedure. Unlike other iodine-based procedures, the Tc-99 sestamibi scan produces no adverse reaction or allergies. After the procedure, the patient does not need to be isolated from other people because the radioactive dye used was very mild.