A positron emission tomography (PET) scan is a special type of medical imaging test. It uses a radioactive drug (sometimes called an imaging agent, tracer, ligand or radiopharmaceutical) to help locate and visualise certain diseases in the body. PET imaging can also be used to monitor how a patient is responding to treatment.
Techniques such as X-ray computed tomography (CT) or magnetic resonance imaging (MRI) are used provide information about the structure or anatomy of the body and its organs. In contrast, PET imaging is used to look at how the body’s cells are functioning. PET imaging agents have the ability to bind to cell surface receptors or be taken up by cellular transporters, providing information about the physiology of cells. A change in physiology may indicate disease long before any anatomical changes are seen. PET imaging is normally combined with one of the anatomical imaging techniques mentioned above, such as PET/CT or PET-MRI, to assist in defining the locations of PET ‘hot spots’ in the body.
The most widely used PET tracer is fluoro deoxy-glucose (FDG) a form of sugar which is taken up by cells as a source of energy. FDG is used extensively in cancer imaging to search for metastases or to monitor response to certain therapies. However FDG does not work well in some tumor types, such as prostate and brain cancer. To overcome this challenge, doctors and scientists are developing other PET imaging agents. One such compound is fluciclovine F 18, a synthetic amino acid which has been developed for PET imaging of cancers where other PET imaging agents such as FDG are of limited use. Blue Earth Diagnostics’ first PET imaging agent, Axumin (fluciclovine F18) is approved in the USA and in Europe for the imaging of men with recurrent prostate cancer.