Radiopharmaceuticals, also known as radionuclides, are radioactive drugs that are injected into veins and travel to cancerous cells.
By measuring the behavior of the radiopharmaceutical in the body during a nuclear scan, the doctor can assess and diagnose various conditions, such as tumors, abscesses, hematomas, organ enlargement, or cysts. A nuclear scan may also be used to assess organ function and blood circulation.
The areas where the radiopharmaceutical collects in greater amounts are called "hot spots." The areas that do not absorb the radiopharmaceutical and appear less bright on the scanned image are referred to as "cold spots."