Nuclear Medicine – Radiation Doses

Nuclear medicine is a medical science that involves the application of radioactive substances for diagnostic and treatment purposes. Nuclear medicine uses a very small amounts of radioactive materials called radiotracers, which are taken internally, for example, intravenously or orally. Then, external detectors (gamma cameras) capture and form images from the radiation emitted by the radiotracers. Sometimes the radioactive drug can be used in the treatment itself: an example is the treatment of thyroid disease with I-131. Nuclear medicine imaging is unlike a diagnostic X-ray, where external radiation is passed through the body to form an image. It also provides unique information that often cannot be obtained using other imaging procedures.

Average effective dose for most nuclear medicine procedures varies between 0.3 and 20 mSv. The common bone scan with 600 MBq of technetium-99m has an effective dose of approximately 3.5 mSv. These doses can be compared with the average annual effective dose from background radiation of about 3 mSv.

In the following points we try to express enormous ranges of radiation exposure as well as a few doses from medical sources.

  • 1 µSv – Eating one banana
  • 1 µSv – Extremity (hand, foot, etc.) X-ray
  • 5 µSv – Dental X-ray
  • 10 µSv – Average daily dose received from natural background
  • 40 µSv – A 5-hour airplane flight
  • 100 µSv – Chest X-ray
  • 600 µSv – mammogram
  • 1 000 µSv – Dose limit for individual members of the public, total effective dose per annum
  • 3 650 µSv – Average yearly dose received from natural background
  • 5 800 µSv – Chest CT scan
  • 10 000 µSv – Average yearly dose received from natural background in Ramsar, Iran
  • 20 000 µSv – single full-body CT scan
  • 80 000 µSv – The annual local dose to localized spots at the bifurcations of segmental bronchi in the lungs caused by smoking cigarettes (1.5 packs/day).
  • 175 000 µSv – Annual dose from natural radiation on a monazite beach near Guarapari, Brazil.
  • 5 000 000 µSv – Dose that kills a human with a 50% risk within 30 days (LD50/30), if the dose is received over a very short duration.

As can be seen, low-level doses are common for everyday life.

References:

Radiation Protection:

  1. Knoll, Glenn F., Radiation Detection and Measurement 4th Edition, Wiley, 8/2010. ISBN-13: 978-0470131480.
  2. Stabin, Michael G., Radiation Protection and Dosimetry: An Introduction to Health Physics, Springer, 10/2010. ISBN-13: 978-1441923912.
  3. Martin, James E., Physics for Radiation Protection 3rd Edition, Wiley-VCH, 4/2013. ISBN-13: 978-3527411764.
  4. U.S.NRC, NUCLEAR REACTOR CONCEPTS
  5. U.S. Department of Energy, Nuclear Physics and Reactor Theory. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.

Nuclear and Reactor Physics:

  1. J. R. Lamarsh, Introduction to Nuclear Reactor Theory, 2nd ed., Addison-Wesley, Reading, MA (1983).
  2. J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.
  3. W. M. Stacey, Nuclear Reactor Physics, John Wiley & Sons, 2001, ISBN: 0- 471-39127-1.
  4. Glasstone, Sesonske. Nuclear Reactor Engineering: Reactor Systems Engineering, Springer; 4th edition, 1994, ISBN: 978-0412985317
  5. W.S.C. Williams. Nuclear and Particle Physics. Clarendon Press; 1 edition, 1991, ISBN: 978-0198520467
  6. G.R.Keepin. Physics of Nuclear Kinetics. Addison-Wesley Pub. Co; 1st edition, 1965
  7. Robert Reed Burn, Introduction to Nuclear Reactor Operation, 1988.
  8. U.S. Department of Energy, Nuclear Physics and Reactor Theory. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
  9. Paul Reuss, Neutron Physics. EDP Sciences, 2008. ISBN: 978-2759800414.

See above:

Medical Exposures