An octreotide scan is a medical imaging study conducted to look for signs of carcinoid tumors, tumors involving endocrine cells, in the body. In this test, the patient is injected with a small amount of a radioactive tracer material and several sets of images are taken to follow the tracer through the body, using a camera sensitive to radiation. The images are read to determine if cancer is present and collect information about the cancer if it is. This information will be used in the development of a treatment plan for the patient's condition.
Carcinoid tumors are particularly dangerous because in addition to causing localized tumor symptoms, they can also release hormones into the body, causing an issue known as carcinoid syndrome. This occurs when the patient's hormone levels become disrupted and the patient starts to experience a constellation of symptoms like weight gain or loss, nausea, skin changes, and so forth in response to the skewed levels of hormones.
In an octreotide scan, the patient reports to a nuclear medicine center for an injection by a technician. The technician usually goes over the patient history to check for any risk factors that might make the test unsafe. After the injection, patients may leave or wait in the center until the tracer has had a chance to circulate, so the first set of images can be taken. Up to two additional image sets may be acquired during an octreotide scan. A radiologist reviews the pictures, looking for clusters indicative of carcinoid cells.
The tracer used, radioactive octreotide, is designed to tag tumor cells in the body while leaving other kinds of cells alone. Bright patches on the scan indicate the presence of the tracer and using multiple sets of scans allows people to see how quickly the tracer accumulated in different locations. They can also follow the movement of the material through the body, looking for abnormalities in the way it circulates and diffuses through the body's tissues. The patient will express the material through the kidneys and should not experience complications as a result of the test.
Before an octreotide scan, patients may be advised to drink lots of water. This will help them flush the tracer when the test is over. Patients who are pregnant or breastfeeding should discuss safety with their obstetricians or pediatricians before proceeding with an octreotide scan. Generally, breastfeeding mothers can feed their infants before the test, express and discard milk once after the test for safety, and then resume a regular feeding schedule.