Q: Radiation safety of the accompanying family members or other hospital workers?
A: (林昆儒醫師)
Generally speaking, the radiation exposure to the family or other hospital workers is much less than workers in the nuclear medicine department (i.e. less than 100 exposures per year.) Accordingly, the exposure dose should be less than 1mSv per year, which is negligible.However, as the case in mobile phones: though there is no evidence that it is harmful, it is suggested to keep the talks as short as possible. In the same way, it is suggested to drink more water to excrete the radionuclides out of the body, to avoid contacts with infants for extended periods of time. These suggestions are not mandatory, and there is no known dangers to others if violating these measures. There was no regulatory requirements for patients receiving diagnostic nuclear medicine procedures thoruought the world, because these patients pose no danger to others.
As the technology advances, there are now radiation detection devices at airports, crematories, and radiation oncology departments in the hospital, to prevent terroristic attacks or to detect radioactive steels. These detectors may give off alarms if patients just receiving nuclear medicine procedures walk through it. Telling the guards that the patient just having nuclear medicine procedures should clarify the situation.

Q: The radiation dose of nuclear medicine procedures?
A: (林昆儒醫師)
The radiation dose from the PET scan is about 5-10 mSv. To better localize the lesions and provide attenuation correction, CT is utilized, and the total dose from PET/CT is 23.7~26.4 mSv. The radiation dose from the CT part is 54~81% of the total dose. If using low-dose CT protocol, the CT dose can be as low as less than 5 mSv, and the total dose will be between 6.35~9.48 mSv.As for other diagnostic nuclear medicine procedures, the radiation dose is mostly below 5 mSv. The doses from thallium scan and gallium scan are higher, 20 mSv and 30 mSv respectively.