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Atul Gawande's Speech - The Checklist Manifesto: How To Get Things RightCheck Dr. Atul Gawande's full speech on “The Checklist Manifesto: How To Get Things Right”. This speech was given on January 13, 2010 at UCSF Medical Grand Rounds. Dr. Gawande highlights the important role that a simple checklist can play in ensuring consistent, reliable, and high quality patient care. |
Radiation Risk Information
The following information is adapted from a presentation given by Dr. Kirk Moon, head of Radiology at California Pacific Medical Center, San Francisco, CA on May 2, 2010. Download complete presentation here.The concern about increasing radiation doses from medical imaging has been building for years due to the dramatically expanded use of medical imaging over the past 20 years. CT usage has increased approximately 10% every year for the past 10 years.
Potential Risks
Heritable genetic mutations in germ cells
- Effect not seen at doses employed in medical imaging
In utero damage to fetus
- Important risk, but special circumstance and not subject of this presentation
Acute radiation sickness
- Only seen at very high doses and in exceptional circumstances. Not discussed in this presentation.
Cancer induction
- The most important effect and the focus of this presentation
Summary of cancer risk
Females are approximately 50-80% more radiosensitive than males across all ages
Radiosensitivity decreases continually with age – young children are particularly radiosensitive
- Newborns are 3-5x more radiosensitive than 30 year olds
- 30 year olds are twice as radiosensitive as 70 year olds
Different organs have different degrees of radiosensitivity
- Brain < neck < chest/abd/pelvis
- Tissues with rapid cell turnover more radiosensitive than others
“Bottom Line”
- Doses associated with most imaging procedures are quite modest and pose little additional risk
- A limited number of procedures carry substantially higher doses than average and have a measurable added risk, even for a single procedure
- The biggest risk isn’t from single procedures but from cumulative dose
Estimated Radiation Doses
The Mean annual effective dose absorbed as “background radiation” is 3.11 mSv. LAR is the “Lifetime Associated Risk” increase of getting cancer from this dose of radiation.
Doses listed are estimates for a standard CT scanner.
| mSv | LAR | |
| CT Head (monophasic) | 2 | .02% |
| CT Stroke (CT, CTA, CTP) | 16-20 | .16% |
| CTA head* | 5 | .04% |
| CT Neck | 3 | .02% |
| CT Cervical Spine | 3.7 | .04% |
| CT Lumbar Spine | 20 | .16% |
| CT Chest (monophasic) | 7 | .06% |
| *MiniCat scan of the head | .01mSv |
Putting the Risk in Context
Receiving 20 mSv of radiation is equal to:
- Smoking 7 packs of cigarettes
- Spending 200 days breathing polluted air
- Driving 4,000 miles in a car
- Flying 25,000 miles in a jet
- Canoeing for 10 hours
- Radiation workers (including radiologists) are permitted to receive a whole body exposure of 50 mSv per year.
- Typical radiotherapy fraction = 1800-2000mSv
- Smoking cigarettes more than doubles risk of AMI (>200% added risk)
What You Can Do
- Ask Questions. Understand why you are having the test and ask your doctor about the radiation dose associated with it.
- Log your lifetime radiation exposure. This will help you and your doctor make an informed decision about the risk-benefit ratio of getting a particular test. Download radiation log here
- Look for low-dose alternatives. The Xoran MiniCat is one such example, with 10-50x less radiation than a traditional CT scanner. This new technology is an especially safe option for children. Click to visit minicat page on our site
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