Radiation in CT scans, x-ray/radiographies and PET scans (III): what to do if my doctor recommends one

This is the last of a series of 3 posts describing:

1. The value and cost/harm of medical tests involving radiation, purely from a scientific perspective.
2. Other factors affecting the prescription of these tests.
3. What to do if a doctor recommends such a test. This post.

CT/PET scans are a good thing, when they are necessary. So, the key is to find out if they are really necessary FOR THE PATIENT (not for the doctor). Without intending to give any kind of medical advice or advice on how you should talk to your doctor (disclaimer!!) these are some of the things I would keep in mind:

1. Tell the doctor if you took any other CT previously. They may be able to reuse those.
2. Ask to explain the risks of not taking the CT.
3. If they ask for a CT with contrast, ask them if they can make first the one without and based on the result, think of doing the one with contrast, or viceversa. Basically, the contrast CT is a full new scan, doubling the radiation...
4. Ask why the doctor is recommending this test given ALL the symptoms. It should NOT be prescribed as a routine or screening test (unless that is what you want... like some asymptomatic people will do a full body scan "just in case").
5. Ask them to do all other less harming tests before this one, if there is no emergency/rush. For instance, an MRI is usually a good replacement (watch out with the argument that it is not, more on that below). Also, you could have the possibility of treating the first suspect illness and see what happens. If symptoms persist, then you may have to move to a CT (or MRI...).
6. You may want to ask for a second opinion. People may not think of that for a CT, but would you do it if they recommend opening you to check if something is wrong inside you? Yes, looks that the two are not comparable, but go through your numbers, check the increased probability of inducing a cancer and then decide if a 2nd opinion is worth...
7. As explained, other kind of scans, like x-ray or mammograms do have much lower levels of radiation. Concerns arise by the cumulative effects of these over the years, specially when used as prevention. These are certainly harder to discern but I would look at policies, not only local but foreign. For instance, it is common practice to have dental x-rays done yearly in US, as insurance covers it, but is it something that you really need, even if free? A US dentist may say so, but somehow, in Europe, this is not done at all.
8. If you got the time, take your time on the discussion. You are the one about to get radiated! And leave few days after the talk to think about, research, consider alternatives, etc... For instance, you may want to check into alternative tests, like the possibility of using an MRI.

Please, read this with common sense. You should not delay the diagnosis of a life threatening condition for a one in a thousand probability of inducing a cancer. Also, if you have been diagnosed with cancer, something like a PET to find secondary sites of a metastasis may well justify the much smaller risk of a future cancer. Nevertheless, if you reach the hospital with all the symptoms of a kidney stone and a previous history of kidney stones, you may want to waive the CT scan that most of US hospitals ERs will suggest doing and see how you feel next day... Bottom line, as I started, imaging tests involving radiation are very useful tools and there are many doctors out there using them in the benefit of patients, but there are many too being prescribed routinely, defensively, or out of ignorance...

Good luck and I hope the posts were helpful

Radiation in CT scans, x-ray/radiographies and PET scans (II): the socio-economic environment

This is the second of a series of 3 posts describing:

1. The value and cost/harm of medical tests involving radiation, purely from a scientific perspective.
2. Other factors affecting the prescription of these tests. This post.
3. What to do if a doctor recommends such a test.

One would think that prescribing a medical test should depend only on the scientific trade-offs. Unfortunately there is a pile of evidence pointing to this not being the case, and that other reasons like economic as well as social play a strong influence on such prescriptions. The following is mostly center in US and few of these reasons may not apply to other regions with, for instance, different healthcare systems.

One can find a good introduction in these two articles:

http://articles.latimes.com/2008/sep/07/science/sci-ctscan7
http://seattletimes.nwsource.com/html/businesstechnology/2011478296_apusradiationscansfda.html

Basically:

1. If you Google hard enough, you can find forums where doctors admit prescribing CTs to cover their ass. You can't blame only doctors for that, as the US society as a whole is prone to sue doctors, so, naturally doctors practice defensive medicine.
2. Patients are also guilty of looking for fast medicine/results. Imaging certainly can help to shorten the diagnosis (like it could do cutting you wide open) but patients just don't think or don't know the effects.
3. Doctors themselves are not the most knowledgeable out there on radiation and its effects/risks.
4. Imaging is a good source of income for the medical establishment.
5. The big imaging instrument manufacturers (GE, Philips, Siemens and Toshiba mainly) do want to sell as many of these machines as possible and apparently in some cases do practice borderline marketing.
6. Patients rely on the doctor (or the system?) warning them ahead of any risks. Unfortunately, patients do not understand that the warnings are NOT for the patients but to cover the medical establishment against law suits should something wrong happen. The awful beauty of radiation based imaging tests is that its effects can usually only be seen after many years and with no conclusive way to trace them back to the original test. As such, many hospitals, doctors, etc... do no see any reason to warn patients about these risks as they very likely will not be found guilty of a future cancer, and warning the patient may create delays, discussions, or ultimately the patient opposition to such a test. If you think this is an exaggeration, you should wonder why although in some places the consent form for a CT scan may include radiation risks (http://www.medscape.com/viewarticle/542613) on many more (see http://www.mibmri.com/ct_scan_consent_form.html or the Medical City Hospital in Dallas, which I happen to know from first hand) this may be limited to the contrast risks, which are on the same order or lower than the radiation risks.  The effects from the contrast are immediate while the effect from the radiation would take decades to manifest. 

Notice that, for instance, a different health system, like the public one where doctors get paid no matter what they prescribe and where the government is actually pressured to save costs (as taxes are paying for the tests) will create protocols where the test has to be strongly justified.

So, after all this information, what can a patient do to know if the test in needed or not? Please see the 3rd post for some suggestions...

Radiation in CT scans, x-ray/radiographies and PET scans (I): the scientific view

This is the first of a series of 3 posts describing:

1. The value and cost/harm of medical tests involving radiation, purely from a scientific perspective. This post.
2. Other factors affecting the prescription of these tests.
3. What to do if a doctor recommends such a test.

So, let's center this post around the scientific facts. The following table lists typical radiation levels for some of these imaging tests as well as other sources of radiation. Notice that these include mainly x-ray, CT, PET and variations of these. MRI and ultrasound do NOT use ionizing radiation and are considered, in principle, safe:

1. Natural background: 2.4mSv/year
2. Air travel crew: 3mSv/year 
3. Radiation worker federal limit: 50mSv/year
4. Dental radiography: 0.01mSv
5. Chest radiography: 0.1mSv
6. Mammography: 0.7mSv
7. PET/SPECT : 7mSv 
8. Chess CT: 8mSv
9. Pelvic/abdomen CT: 10mSv
10. CT Angiography: 15mSv
11. 50% of cases die in 30 days: 3Sv

Notice that:

1. Just by living, we do get a decent level of radiation (see #1)
2. That there is a very wide range between tests. For instance, a pelvic CT radiation is like 100 chest x-rays (this number is actually probably conservative).

Question comes on the relation between radiation dose and cancer. The following link can provide some guidance:
http://www.xrayrisk.com/calculator/calculator.php

Notice that:

1. Risk factors are extrapolations/guesses.
2. A ballpark is about 0.1% increase in cancer risk for a 10mSv exposure of a 30 year old person.
3. The younger the higher the risk.
4. Risk is additive. The more tests you get in your lifetime, the higher the cancer risk.

The actual dose of the test can vary even for the same test. For CT, to exactly compute the dose from a given test (once the test is done and the data of the test obtained from the radiologist), one can follow this example:
http://answers.google.com/answers/threadview/id/742075.html

So, the above would give us the "cost", the "risk" of performing such a test, but what are the benefits? In this context, we all have heard the expression "the benefits outweigh the risks". There are many conditions out there and talking about the benefits or the need of medical imaging would be plain impossible, but basically, one could say that the bigger the radiation the test carries, the better the image and the bigger the benefits, with a CT or a PET scan providing beautiful images and information. Notice that pure information does not imply need for the test. We may already know the reason for the disease (from some other diagnosis) and all what the test would do would be to confirm the diagnosis. Or we could take the path of treating the likely disease without 100% confirmation from a CT scan, and if that solves the problem, then just move on (saving with this approach the radiation and cancer risk). Ultimately, it is for the doctor to explain the benefits and alternatives of such test to the patient and for the patient to decide (see the 3rd post on this topic).

Let's move on now to other factors that may not be necessarily explained by the doctor and that do affect the prescription of imaging tests, at least in US.

Update (3/23/2013). I got across this alert from the Joint Commission  on this topic. May be useful reading...

Patientslikeme.com

Working couple of years back in the symptoms of my own illness at the time, I missed many tools that I would have certainly loved to have to find the data I needed, specially when one thinks in the times of the Internet: Free access to journal papers (of research partially paid by MY taxes), forums with good tools to search/screen through the answers, good symptoms search tools, tools to track my symptoms and any other factors and see how those correlated to my evolution or that of other similar patients, etc...

Eventually I managed to cure myself (after repeated failures of my PCP), by covering with ingenuity and hard work for some of the lack of those tools, and along the way, I thought it would be good to create those tools for many other patients. This may look like a very altruistic/philanthropic goal, but ultimately, let's be honest, I or somebody I care about would be benefiting from it in the long run, when illness strikes again.

So, while I was cooking some of those tools/sites, I failed to find a site called patientslikeme.com, till my friend, just yesterday, mentioned it to me. I was hit again by the "duh, I am late again" feeling, but at the same time, I thought that better that somebody does something instead of me thinking about it. I even looked at it with more sympathy when I read about the story of the founder, who came up with this project while fighting his brother's ALS. More here:
http://www.patientslikeme.com/about

So, just signed up and here are just quick thoughts, not so much on the tools/interface/etc (where I do have my opinions) but on the spirit of the site. Honestly, I am a bit disappointed. They do say up front (good that they don't hide that) that they are a for-profit organization. Question is at what expense, if any. Their first core value is: "putting patients first". That sounds exactly what I would have in mind for mine, so, great! So, they don't sacrifice the advance of science, a cure for those patients, etc... in order to make money, right? Errrrr... Well, not really. That's actually not what they mean for that sentence and the detailed explanation can be found here:
http://www.patientslikeme.com/help/faq/Corporate#c_corevalues

"Simply stated, this means "Patients First."  You, our patients, trust us with your most valued health information. We honor that trust, and we are dedicated to advancing the knowledge of your conditions with the information you share."

Not bad, but will they give it 100%? Not really. An example of it can be seen in their research policy:
http://patientslikeme_research.s3.amazonaws.com/Research%20Policy%20May2009.pdf

One of their assets is their patients. Yes! Patients are an asset to them. The information patients disclose is an asset too. And patientslikeme.com will no offer it for free to everybody out there. It is not about protecting patient privacy. They actually will sell it to the buyer. It is about protecting their pockets. If a professor doing a study in MS would like to run a short questionnaire or few test through 100 patients to further advance his research, he can't do that, without permission AND payment: "Please note that we do not have a patient referral service which is free of charge".

Anyhow, do not want to be too harsh on the site. I want to check few more things and I also understand that sites require money to run. Money brings also quality. But "for profit" is just not what I had in mind in this case... I got to think what I would do instead, though... I'll leave for another post thoughts on healthcare financing, but so I am not misunderstood, I do not necessarily look down on anybody that with the current society makes as much money as possible out of sick people... although I do hope for a change in society.