The risks associated with low-level exposure to radiation are still not fully understood but as a general rule, the amount of exposure is kept “As Low As Reasonably Practicable” (ALARP), so that the least amount of radiation is used to achieve results that are still accurate.

Sometimes, patients undergoing nuclear medicine procedures require special preparation beforehand if accurate results are to be achieved. For example, certain medications may need to be stopped or a certain diet may need to be followed. Advice is usually provided by the nuclear medicine team about exactly which patient preparations may be required prior to a scan.The effective radiation dose varies according to the type of study performed. The dose may therefore vary from less than or similar to that of a person’s every day environmental background dose, to a dose that far exceeds it. Similarly, the dose may be less than, similar to or higher than the dose received during a pelvic or abdominal computed tomography (CT) scan.

For patients undergoing a nuclear medicine analysis, the radiation is generally administered internally. The radiopharmaceutical agent is given to the patient orally or intravenously, as opposed to the application of external beams seen in radiotherapy. The radiopharmaceutical used emits ionizing radiation as it passes through the specific organs or tissues it is attracted to. This targeted radiation only travels a short distance, meaning damage to healthy neighbouring tissues or organs is minimized. Usually, these therapies are performed on an outpatient basis and most patients can go home after therapy.