The latest news about CT scan abuse and the subsequent excessive radiation exposure to the public is very disturbing. A recent issue of the Archives of Internal Medicine features 2 articles describing their findings in regard to the use and possible misuse of CT x-rays. There is no point in my regurgitating the details of the two articles. The reader can study the articles without my noisy input.
What I would like to point out is that this is a case of faulty administrative control over the exposure of patients to hazardous energy. Who is the gatekeeper for access to a CT scan- the primary care doc or a consulting radiologist? If it is the primary care doc, is he/she up to speed on the exposure/dose details? Does the primary care doc know the dose and variability in radiation exposure for a given workup? Does the dose vary with the model of CT scanner? How much resolution is really necessary, anyway? Does half the dose give half the resolution, or is there some other law relating transmitted energy to resolution?
Maybe the gatekeeper should be the radiologist. The radiologist should be able to calculate a radiation dose and speak knowledgeably about the details of the risk. But should the radiologist be in a position to second guess the primary care doc? Does anybody provide feedback to the primary care doc as to the wisdom of a given CT scan? Doesn’t sound like that would work very well.
So, who is really the gatekeeper in regard to the merits of any given CT scan given to the patient? But more importantly, how the hell can it transpire that radiation exposures are far higher than anybody apparently realized??? Radiation technology and radiation biology are mature sciences now. And presumably, radiologists are trained to pay attention to these kinds of details.
Where the HELL were the radiologists when these instances of excessive exposure were accumulating?? Isn’t that why we train them … to provide expertise in the use of ionizing radiation in medicine?? Were they busy? Did they have something else to do besides monitoring the use of radiation on actual patients?
Could it be that people in the CT business are more captivated by the industrial light and magic of imagery and special effects rather than the grubby details of dosimetry?
Lamentations on Chemistry 
Hmm. Last year I had a stress fracture of the sacrum from running. The doc needed an mri to diagnose the damn thing.
Then he said this was an uncommon stress fracture and he wanted to know why and eliminate the possibility of cancer in the area and ordered a CT.
Risk/benefit analysis – If he had found cancer I’d be singing praises of the CT. Now, I wonder about its risks – though I’d place them at pretty damn small and the benefit if he had found something as significantly higher.
That said, the commentary on regional variation of dosage indicates that radiologists – among the laziest (oops that just slipped out) and highest paid of specialties – need to set the standards of care with these instruments more tightly.
Reminds me of the old fitting of shoes with x-rays, a little. Just less extreme. I wonder if any epidemiologists have aimed any studies at that corner of our history.
thanks for the eye opening link, Gauss!
Cost/Benefit issues are always present with radiation exposure. I have no problem with the use of x-rays or other radiation in general. What shocks me is the lack of oversight this area seems to have had.
I wonder if the technology and data manipulation capacity is just so dazzling and so facile that the keepers of this magic have lost their fear of it? Of course, a CT instrument that is not in operation is not paying its way. If you’re a hammer, everything looks like a nail.
Radiation is very abstract, relying on statistics for correlation, and the biological effects are delayed. Perhaps this is a normal result of a potentially hazardous technology becoming “normal”.
We forget all of the beagles, soldiers, downwinders, uranium miners, and Rongelap islanders who unwittingly provided knowledge of radiation effects. The operators of CT systems have no excuse.
http://www.rmiembassyus.org/Nuclear%20Issues.htm
Management is about process not product. Everybody perfectly enforced and perfectly followed the rules. Productivity bonuses for everybody! Anybody demanding the rules must be changed is thereby proven incompetent to comment – and must be discharged for cause/insubordination.
The equipment’s services are ungodly expensive billed to patients. Of course it works properly! The accusations are unfounded for the errors cannot occur,
http://courses.cs.vt.edu/cs3604/lib/Therac_25/Therac_1.html
http://en.wikipedia.org/wiki/Therac-25
I think it is worth noting, as a medical professional, that radiologists do not directly oversee image acquisition. This is a job for technologists. The radiologist interprets examinations and, yes, makes suggestions on how the images should be acquired. However, the radiologist cannot ultimately be held responsible for mistakes that are made exclusively by technologists. If you are looking for your gatekeeper of radiation control, look no further than the person pushing the button. I am of the camp of those wishing to see tighter federal oversight in areas like CT radiation dose control. It is ridiculous that this technology has thus far gone unregulated.
This sounds like an example of the silo effect, with radiologists and technologists operating in separate camps. Somebody must take responsibility for radiation safety. It seems to me that at least some resonsibility must track back through the channel of people professionally trained in the clinical use of radiation.
Obviously, the person pushing the button must have a safety mentality and enough depth of knowledge to detect off-normal circumstances. But just how much descretion does a technologist have, anyway? And, realistically, what happens to techs who question the the judgement of those princely few who have MD behind their names?
It seems odd to me that radiologists do not directly supervise the administration of hazardous energy to people who are ill. How could it be that radiologists have become so distanced from the pragmatics of their field? Shouldn’t we expect a bit more “hands on” action by these folks?
When an order for an x-ray or other tool of nuclear medicine arrives at the clinic, is there an actual physician present to sign off on dose calculations? What administrative controls are in place? Does the computer software controlling the instrument have any annunciators that require verification of the settings befor the exposure is made?
If they are too busy interpreting the results, could it be that there are too few radiologists? Is the point of the licensing board to control the quality or the quantity or practitioners? Call me cynical, but it seems like there is artificial scarcity in this market.
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It has been 6 1/2 years since writing this post and much has changed for me in regard to my questions about CT scans and radiation dosing. Having undergone intensive radiation treatment for throat and prostate cancer, parts of my body have received large doses of x-radiation. I have received sizeable doses from two 18F-Deoxyglucose and one technetium pet scans as well. During this time I asked the health physics guy about the matter of logging accumulated radiation dose and the answer was “No, that is not done. The harm of radiation is much less dangerous than the cancerous lesions that were targeted.” My head and neck oncologist at Anschutz estimated that the chances of acquiring a cancer from the neck radiation to be ca. 1 %. This is a substantially lower risk than the cancer itself and in my judgement, an acceptable risk.
Modern Intensity Modulated Radiotherapy (IMRT) equipment is capable of delivering maximum dose to the target volume while minimizing dose to surrounding tissue. These accelerators have built in CT scanning equipment that allow for precise positioning of the patient in the beam, beam intensity modulation for variable energy delivery, and have lead leaf collimators that constantly shape the beam as it circles the target for optimum deposition of energy.
https://www.varian.com/oncology/solutions/radiotherapy
The major hits to body parts from the neck radiation were the loss of 2 molars from chronic dry mouth, loss/distortion of taste, and loss of thyroid function. But these are things a fellow can easily live with so no complaints here.