The number of radiopharmaceuticals in clinical use is rapidly growing, thus allowing the medical community better access to detail information on the characteristics of the different types of tumours.
A radiopharmaceutical can be seen as an entity made up of a radionuclide and a vehicle molecule with high affinity – or binding power – for a tissue or a specific function of a human organ. It may also comprise only the radioisotope itself if it shows suitable biological properties.
Radiopharmaceuticals are used to produce images of organs or tissues of interest, a process that is called scintigraphy. A type of medical device known as gamma camera is able to detect the gamma rays emitted by the radioisotope. It generates in a non-invasive manner images that reflect the function of the organ or tissue under investigation.
The most widely used radioisotope in diagnostic nuclear medicine is technetium-99m. It can be attached to several specific molecules, allowing the diagnosis of many diseases, including certain types of cancers. For instance, technetium-99m-MDP (methylene diphosphonate) is widely used to detect bone metastasis associated with cancer.
