Because gallium is chemically similar to iron, it binds to molecules in cells the same way iron does. Since iron also binds to tumors, inflammatory proteins and the cell walls of bacteria, the detection of the radioactive decay in a gamma ray camera will outline such structures in the body.
Several symptoms point to a gallium scan being an appropriate procedure:
- A fever with no known origin
- Lung inflammation in an immunocompromised patient
- When sarcoidosis or tuberculosis is suspected or being treated
- Where osteomyelitis of the vertebrae is suspected
- In cases where the lungs have been affected by a toxic drug
- In patients with very low white blood cell counts