Citation, DOI & article data
Radiopharmaceuticals are drugs that are bound to radioactive substances. The pharmaceutically active portion determines the activity that will be measured and the radioactive portion emits radiation that can be measured by the scanner.
A number of radiopharmaceuticals are used in human imaging. They share the physical characteristic of emitting radiation of various kinds. In some cases the emitted particles are detected either directly or indirectly by specialized equipment (e.g. SPECT, PET, gamma camera, etc.) to generate imaging. In other cases, the agent is used to have a tissue effect locally.
Properties of an ideal radiopharmaceutical:
short physical half life time
eliminated from the body with an effective half life time approximately equaling the examination time to prevent subsequent exposure to the body
gamma rays emitted should be monoenergetic (~150KeV)
high specific activity
localize largely and quickly at the target site
decay into a more stable daughter nucleus
easily and effectively attached to the chemical compound at room temperature
cheap per patient dose
can be easily produced or kept at the hospital site
The radioactivity of radiopharmaceuticals are commonly measured by using miliCurie (mCi) and megaBecquerel (MBq) where 1mCi is equivalent to 37MBq 1.
- 1. Measurement units. Human Health Campus. International Atomic Energy Agency (IAEA)