MIBG (meta-iodobenzylguanidine) scans help locate and diagnose certain types of tumors in the body. MIBG is a substance that gathers in some tumors, particularly neuroblastoma tumors. When MIBG is combined with radioactive iodine (tracer), it provides a way to identify primary and metastatic (spread) disease. MIBG scans are helpful for locating both bone and soft tissue tumors.
The test is performed by injecting a small amount of radioactive dye (tracer) through an IV. Pictures are then taken under a scanner that is similar to a CT scan. The scans may occur 24, 48, or 72 hours after the tracer is given. Doctors are looking for bright spots on the scan, these indicate cancer cells.
An MIBG scan does not hurt, but it may be difficult or uncomfortable for a child to lie still for the test. Young children may be given a sedative to help them lie still for the entire test. A special medicine is given to protect the thyroid gland from the radioactive substance in the tracer.