In this video, Dr. Atul Verma, Head Dept. of Nuclear Medicine, Fortis Hospital, New Delhi, will talk on how long does the radiation stays in the body He explains that the radiation depends on the radiotraces, depending on the half-life of these radiotraces. Isotopes have different half-lives. For example, thallium has a half-life of 73 hours. Generally it is checked accordingly to the radiation exposure to the patient. When the half-life is of short duration, then the drug can be injected more. Dr. Atul will explain these with examples.