CT Scans and Cancer Risk

[nopain]

Certainly something to think about. I have had 1 CT scan and refused all others. Mine was required before the Doctor would perform a proceedure.

The frequency with which XRays are prescribed in so many Medical Fields is alarming to me. Every time I go to the dentist they want to shoot new films. I went to an Oral Surgeon for TMJ evaluation and they shot me 3 times because the Tech kept screwing up. I had a chest Xray that had to be redone because the Tech didn't size the equipment properly.

I'm not an idiot, I understand radiation and the effects. I don't need another graduate from the South County School of Medical Helpers to tell me that Xrays are "low risk" and I'm only getting as much exposure as you would get on an airline flight.

The bottom line is sometimes they are necessary, and CT Scans blast you so much harder than regular XRays or even Flouroscopy. But it's your job to weigh your own risk potential after you educate yourself.

Exactly how much radiation is too much? Because CT scans came into vogue in the 1980s and radiation-induced cancer takes roughly 20 years to develop, long-term studies of CT scans and cancer are still under way. But scientists are already anticipating future health implications. Indeed, researchers found a population of 25,000 Japanese post-atomic-bomb survivors who were exposed to roughly the same amount of radiation as two CT scans. Based in part on those studies, the Food and Drug Administration estimates that an adult's lifetime risk of developing radiation-induced cancer from a CT scan is roughly 1 in 2,000. Worse, the risk for children is even higher.

Source: http://news.yahoo.com/s/time/2008063...rousarectscans

[Roblin]

You are so right. I went to radiology school and we had a radiation rotection class we took that made me realize how dangerous radiation really is. Most doctors except for radiologists have no idea how dangerous it really is. They are not required to take a radiation protection class. CT exams and fluoroscopy exams are the worst offenders. A chest x-ray is rather low if it does not have to be repeated. It is sad but so many techs out there really don't care about repeats because they don't see the immediate effects of radiation and they figure most patients don't get that much. However a spine patient gets a bunch. The mAs is very high for a lumbar x-ray because of having to penetrate the bony structures of the spine. If one has a choice between an MRI and a CT, the MRI is the best choice because no radiation is used in an MRI. Unfortunately, the artifacts of metal implants make an MRI pretty useless at the levels of the implants. When being exposed to radiation always ask for a shield if it will not interfere with the area they are looking at. The tech should automatically shield you, but 9 out of 10 times they are too lazy to do it. I also ask for a thyroid shield if they are not shooting my neck. They look at me weird, but if you go into surgery which I used to do a lot, we all wore thyroid shields and a lead apron while using the fluoroscopy machine. I hate to think what I have ahead because of all the radiation I have had in the last few years. Unfortunately if you sign up for an FDA study it involves a lot of very frequent spinal x-rays which are relatively high in the dose of radiation you get. If someone tells you they aren't that bad, they are either ill-informed are they are lying to you. People need to watch out for themselves in the area of radiation protection because the medical field uses radiation way too freely, probably to cover their a...!
Roblin

[Maria]

The last time I was sent for a CT scan I was concerned about the amount of radiation so I asked the tech who didn't know, I asked an RN who didn't know, I asked the doctor and she told me not to worry, it wasn't that bad.

I had read somewhere that the amount of radiation from a CT scan is about 15 times that of a CXR (chest xray). I had googled a link that supposedly would give the amount of radiation with various diagnostic exams but the site didn't work.

I know the information is probably easily accessible however perhaps one of you has that information or a website that would give this information?

thanks much~ from someone who has too many xrays, CT scans and probably any other test that is bad for overall health in some way related to my long spinal trek!

[nopain]

Roblin your reply brings up an interesting point and more questions in MRI vs. CT Scan

Let’s factor out

Anxiety and Claustrophobia
Metals and how they effect MRI
Length of time of Procedure/Ability to tolerate time
Cost

What can a CT Scan Provide in terms of Diagnostic Imaging that an MRI can not?

------------------ Resources Below------------------------

This is interesting but boringly technical

http://www.mja.com.au/public/issues/...art/smart.html

Blood test to determine exposure

http://www.buffalo.edu/reporter/vol31/vol31n18/n8.html

This link is a PDF file that shows the amount of radiation from the most common tests (It's contained within the report Table 1 Page 2)

www.ccjm.org/PDFFILES/Lockwood6_06.pdf


Scary Fluoroscopy Injuries (I've had 4 of these now!!! Up to an hour long! - the procedures not the injuries - maybe those are coming down the road for me).

http://www.fda.gov/cdrh/rsnaii.html

FDA Table at the bottom of this links shows comparison of scans to how much you would receive naturally over a period of time.

"Estimates of the effective dose from a diagnostic CT procedure can vary by a factor of 10 or more depending on the type of CT procedure, patient size and the CT system and its operating technique."

The table says a Typical Lumbar CT is equivelent to what you would receive naturally in 158 days... but the worse case scenario would multiply that to 1500 days!!! Yikes!

http://www.fda.gov/cdrh/CT/risks.html


Yes it's the mighty Wikipedia the source to maybe be trusted At the bottom of this links is information on how much exposure causes what kind of symptoms.

http://en.wikipedia.org/wiki/Radiation_poisoning

Here's a way to convert Exposure Units from one to another

http://online.unitconverterpro.com/c...-exposure.html

This link wasn't working but hopefully it will lend good information when it does. It's the American Nuclear Society Radiation Dose Chart.

http://www.ans.org/pi/resources/dosechart/


Apparently there is no one definitive chart as there are so many variables from patient size and build, to the equipment being used, to the skill of the technician and the length of the procedure.

What I can say definitively is there is on one keeping track of the procedures for you. Error on the side of caution. I do everything I can to avoid Xray exposure. But when they are going to stick a needle in my neck close to my spinal cord my choice is to let them do it blind and suffer potential failure of the procedure or paralysis or just let them do it and take the radiation risk.

No good answers once again.

[mmglobal]

At one of the conferences, a doctor presented to surgeons on the risks associated with radiation for the surgeon. I don't remember the numbers, but way too many surgeons will die unnecessarily of Thyroid Cancer because of inadequate respect/precautions against radiation. (leaded glasses, appropriate shielding, checking lead aprons as they lose effectiveness and get worn out, etc...)

The number that did stick with me was, 1 minute of flouro = 2000 chest xrays.

Great topic...

Mark

[Roblin]

Yes, 1 minute of fluoro is very high. If it tells you anything there is a 5 minute warning bell on the fluoroscopy machine to warn the surgeon and it goes off every 5 minutes. According to Steven B. Dowd & Elwin R. Tilson in "Practical Radciation Protection and Applied Radiobiology" 2nd edition:
"The absorbed dose rate in the skin from the direct beam of a fluoroscopic x-ray system is typically between 0.02Gy/min and 0.05Gy/min (2 to 5 rad/min), but may be higher, depending on the mode in which the equipment is operated and the size of the patient. Even typical dose rates can result in skin injury after less than one hour of fluoroscopy. Physicians performing high-dose fluoroscopy procedures should be aware of the potential for serious, radiation induced skin injury caused by long periods of fluoroscopy during these procedures. It is important to note that the onset of these injuries is usually delayed, so that the physician cannot discern the damage by observing the patient immediately after the treatment."
Different states have different laws about fluoroscopy. Some state you have to be a licensed physician to use fluoroscopy but I live in Texas and in Texas the radiology technologists can run the fluoroscopy machines and I used it on patients while I was in school. It can be kind of scary because I knew of one tech that didn't care about patient care at all and she would never change the settings on the machine because she was too lazy and prided herself on being quick...no matter if you overradiate your patient! She was really bad about x-rays too. She didn't take time to position the patient correctly and ended up with a lot of repeats. Spine x-rays, shoulders, knees, femurs and the skull give quite a lot of radiation and you should not be having to repeat them because you are too lazy to get it right the first time. Actually, chest x-rays are rather a low dose because it is mainly air you are penetrating. You still don't want the tech to have to repeat it or not use the collimation guide that helps from scattering the x-rays. If anyone is interested I can tell a little bit about the difference in the MRI and CT scan later. Always ask the tech to shield you when possible. The most sensitive body parts to radiation are thyroid, breasts, and gonads.
Happy belated 4th to everyone...hope it has been a nice weekend!
Roblin

[Roblin]

I was also going to comment on the lead aprons. They should be hung up when not being worn but at some facilities they are just kind of tossed on a hook or on a chair. This can actually cause cracks and the apron should be x-rayed every few months to see if there are any cracks in it because if there is a crack then the person wearing it is getting the unwanted radiation but most doctors I encountered in the operating room had their own special apron that they wore and if they are half-way educated in radiation protection they check their apron and thyroid shield, and gloves on a regular basis.
Roblin

[nomorepain]

This is scary, reading all of this from the eyes of a
Prodisc US Trials patient, for the last 5yrs after my surgery
i've had 10 or so x-rays of my implants per year, i was rushed into a CT scan just 12 hours after my prodisc surgery due to uncontrolable swelling in my legs, and
another scan at 1 1/2 yrs for another health issue, and of course i have my surgical notes from my prodisc surgery
and had some time under the flouroscope & countless x-rays before surgery of my lumbar spine, hmmmm makes me think!

[dshobbies]

Too often, a new medical miracle comes along... only to find some years later the consequences suffered as a result.

Back in the '40s and '50s, many babies, especially premies were put into full incubators without eye protection. Though babies were saved th pure oxygen caused blindness. In the '50s another common practice was to irradiate tonsils as opposed to removing them. The health problems this caused are too numerous to mention.

Even when the consequenses are known, we often must choose the better of two evils. I never realized the connection between health care and politics!!!!

Radiology allows doctors an insight they wouldn't otherwise have. To the patient, is it worth the risk? A difficult question to answer for most... you're damned both ways.

However, with cancer so prevalant these days, would we know if the cancer was caused by x-rays or the radioactive waste/rain that has become a part of our lives or just plain chance?

The price we pay for living better than previous generations.... to be continued in 20 years.

[chasswen]

well that was very well said dshobbies. keep up the great reply s as that one just pain rocked.
chuck