Monday, September 11, 2006

PEM Flex and Radiation Exposure - still getting the test

I have received some further information that has helped me decide to go ahead with the PEM Flex test on Wednesday. Here is a very good link on radiation exposure and limits in the following link:

http://www.arpansa.gov.au/is_rad.htm

It turns out that airline pilots actually receive a fairly high dose of ionizing radiation and so do frequent flyers. I don't believe anyone realizes that airline flight even as a passenger, gives them a fairly good dose of ionizing radiation - but that level is deemed safe for the normal airline passenger. It seems the negative effects are more likely on the genes I pass on to offspring and since I don't think I will be doing that at this point, the DNA I damage is mine to keep.

So I have decided that one PEM Flex test is fine. The manufacturer is aiming to reduce the amount of radiation exposure for patients with the aim of allowing the PEM Flex test to replace the annual mammogram and I hope that they can achieve that since the PEM test is SO much more useful than mammograms.

I wanted to add this information, generously provided by the Naviscan PEM Flex manufacturer's Eastern Sales Director to me when I asked about radiation hazards:

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The National Council on Radiation Protection and Measurements gives some examples of common radiation exposures.9,10,11 Members of the general population throughout the United States receive, on average:

• 1,300 millirem per year from smoking one (1) pack of cigarettes per day;
• 650 millirem per nuclear medicine examination of the brain;
• 405 millirem per barium enema;
• 245 millirem per upper gastrointestinal tract series;
• 150 millirem per nuclear medicine examination of the lung;
• 110 millirem per computerized tomography of the head and body;
• 7.5 millirem per year to spouses of recipients of certain cardiac pacemakers;
• 6 millirem per dental x-ray;
• 5 millirem per year from foods grown on lands in which phosphate fertilizers are used;
• 4 millirem per year from highway and road construction materials;
• 1 millirem from each cross-country airline trip;
• 1 to 6 millirem per year from domestic water supplies;
• 1 millirem per year from television receivers;
• 0.5 millirem from eating one-half pound of Brazil nuts;
• 0.3 millirem per year from combustible fuels, (i.e., coal, natural gas, and liquefied petroleum);
• 0.2 millirem from drinking a quart of Gatorade™ each week; and
• 0.1 millirem per year from sleeping with one’s spouse. (sic: hehehe - that's a good one!)

When all of the different types of background and medical radiation are considered, the average member of the U.S. population typically receives a radiation dose of about 360 millirem per year. The radiation dose potential for a hypothetical physician participating in the study using the PEM Flex Solo on a patient administered 10 mCi of 18FDG, is over 450 times lower than the dose associated with typical background radiation exposures received by average members of the U.S. population by virtue of being alive.

The concept of a given amount of radiation exposure producing a particular effect is no different from that which applies to the medical administration of drugs. Just as one aspirin is unlikely to harm a patient and 300 may very likely be lethal, so too will a large amount (dose) of radiation produce serious biological consequences, while a small amount has no discernible effect.

It is also essential to recognize the importance of the rate at which the radiation dose is delivered. To continue the preceding analogy, 300 aspirins swallowed in one day may kill the patient, but 300 aspirins taken over a period of one year is unlikely to cause any personal harm. The same concept applies to radiation exposures, such as that associated with performing a study with the PEM Flex Solo on a patient administered 18FDG.
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Ok so what about the patient receiving the injection vs the physician or radiologist giving the test? That question is not really answered in the provided document although extrapolation can be made that having received the injection would be a higher dose of radiation than the physician who comes into contact with the patient. Stay tuned for the answer - if I can get it.


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