Whole Body Scanning Using Computed Tomography (CT)
You may have noticed media
advertisements from companies offering whole body CT scanning. This is a
procedure that is meant to provide the public with early detection of cancer
and other diseases. Facilities offering these CT scanning exams are regulated
by the Department of Health and inspected periodically. The Radiation Rules
and Regulations in Washington (WAC 246-225) require an order or prescription
for any diagnostic x-ray exam, including all CT scanning procedures. We
therefore require all CT scanning facilities to have a licensed practitioner
on site to comply with this rule, i.e., to interact with each
customer/patient, and to “prescribe” the CT exam. The facility must have a
physician, a radiologist, an ARNP (advanced Registered Nurse Practitioner), a PA (Physician’s Assistant), or any other licensed practitioner of
the healing arts whose scope of practice allows them to prescribe x-ray exams.
Attention should be given, however, to the fact that the CT exam is one in
which the dose to the patient is very high, potentially 1000 times more than a
chest x-ray, and therefore is a health issue that requires careful consideration
by the patient. Many state health departments across the United States are
taking steps to ensure appropriate use of these CT scanners. To further help
you understand our concerns, we have
provided answers to some common questions about whole body CT scanning
(see below).
In addition, the Food and Drug Administration (FDA)
has also issued a
position on this topic at their website.
Self-referred
Walk-in CT “Screening” in Washington State
June 2002
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What is meant by the word “screening” with regard to
x-ray
examinations?
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What is a CT scanner?
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Are there CT scanners in operation at other facilities?
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What questions should I ask if I go in for one of these CT scans?
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Why should I be concerned about having a CT scan done?
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How much radiation dose do I get from a CT scan?
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What are other examples of x-ray screening?
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What do professional organizations and the federal government have to
say about this?
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Are other states restricting use of these walk-in CT businesses?
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What is Washington doing?
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What are the Washington State regulations regarding x-ray screening?
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How many “screening”
CT facilities do we have in Washington?
What is meant by the word “screening” with regard to
x-ray
examinations?
Screening
is defined for these purposes as taking x-rays on people without a licensed
practitioner (i.e., doctor, dentist, etc.) first examining the patient and
prescribing the x-ray. Screening implies looking for disease in an
asymptomatic population, in other words, testing people who have no health
complaints or reasons to think they need health care. Many years ago,
this was common when clinics across the country parked mobile units outside
shopping malls, inviting people in, without seeing a doctor first, to get a
chest x-ray. This was eventually made illegal in state
regulations. You cannot go to a clinic or hospital and demand an
x-ray of yourself. A licensed practitioner of the healing arts (MD, DO,
DC, DDS, DMD, ARNP, PA, etc.) must order each x-ray.
What is a CT scanner?
It is
a machine that emits a narrow beam of x-ray which passes through the patient's
body and which is then stopped by an array of detectors. A
then
computer then creates a cross-sectional or “body slice” image on a screen.
The image can be magnified, enhanced, darkened, lightened, and also printed or
saved on a disk. The x-ray tube and the detectors are arranged in a
doughnut-shaped housing so that they are directly opposite each other, but
free to move as a unit in a 360-degree arc.
Are there CT scanners in operation at other facilities?
Yes.
There are 140 CT scanners in Washington. Many hospitals have had CT scanners
for years and they are used for many different parts of the body, but
typically the head and the trunk.
What questions should I ask if I go in for one of these CT scans?
You
should ensure that you are first seen by a licensed practitioner and discuss
with him or her the reasons for having the CT examination done, e.g., health
concerns, pain, etc. Ask how much dose you will be getting from the CT exam
(do not accept a comparison to “days in the sunshine,” a flight across
country, a chest x-ray, etc.). Ask if the technologist is a Registered
Technologist (“RT”) certified by the State Department of Health.
Why should I be concerned about having a CT scan done?
You
may not want to pursue having a “screening” CT done. (We shall continue to
call them “screening CTs” even though it is technically NOT screening if a
practitioner is prescribing the scan.) The reason is that very little evidence
exists to demonstrate a value of these exams to walk-in or “self-referred”
people; in other words, it is
rare that disease is found in people who have no adverse signs or indications.
Thus, the cost and the risk of the radiation exposure outweigh the benefit.
How much radiation dose do I get from a CT scan?
The
dose from a CT exam is very much higher than other common x-ray exams. For
example, an x-ray of the head such as a sinus film or a dental cephalometric
film generally exposes the patient to about 20 to 100 millirads, whereas a CT
of the head gives the patient a dose of around 5000 millirads.
What are other examples of
x-ray screening?
Another
x-ray exam that is increasing in popularity is the bone densitometry exam, or DEXA scan. This is a very, very low exposure
x-ray of the finger or heel or
trunk, designed only to measure the density of the bone it passes through, and
therefore not much x-ray dose is required. Some facilities have applied for
permission from the State Health Officer to conduct these “screenings” on
a select population subject to bone fractures, i.e., the elderly. This is done
without first seeing a physician, but it is a select population, a very low
exposure, and the facilities have obtained permission to do so.
What do professional organizations and the federal government have to
say about
this?
The
American College of Radiology (a national organization of radiologists) has
issued a statement suggesting that full-body scans could lead to findings that
could be misinterpreted, cause unneeded follow-up exams or treatments, and
waste patients’ money. The
federal Food and Drug Administration (FDA) enforces performance standards upon
the manufacturers of CT machines, but it is up to the states to regulate the
use of x-ray machines. Nevertheless, the FDA has questioned the use of CT
scanners for walk-in patients.
Are other states restricting use of these walk-in CT businesses?
Yes. Most states have regulations similar to Washington regarding prohibition
against screening. Other states are also raising this issue and requiring
businesses that wish to operate these CT screening facilities to have written
physician’s orders on every person who wants a scan done.
What is Washington doing?
We are
requiring them to have a licensed practitioner on site at every facility. They
cannot simply open a business with a CT scanner and
simply employ a cashier and a technologist, for example. They must have
a licensed practitioner (a Physician’s Assistant, a radiologist or another
physician specialty) present when customers walk in. We cannot, however,
dictate how extensive the examination and interview need be, before the scan
is taken, since that would be interfering with the practice of medicine. It
may be quite a cursory “examination,” but that is out of our control.
What are the Washington State regulations regarding
x-ray screening?
WAC
246-225-020 prohibits x-ray exposures without an order by a licensed
practitioner. Screening can, however, be conducted under approval of the State
Health Officer after submission of adequate answers to 14 questions found in
that WAC. These questions address the issues of appropriate population,
specific disease, frequency of testing, handling results, and duration of the
whole screening program.
How many “screening”
CT facilities do we have in Washington?
We
have 8 facilities in Washington doing CT “screening.”
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