Last December we received a letter from a mother who had just read
an article which warned that young girls undergoing x-ray should
wear protective breast shields. She wanted to know where she could
buy these shields for her daughter. The question made us realize
that there are many misunderstandings about the x-ray process. To
broaden our knowledge, we interviewed Dr. Joseph P. Dutkowsky, Assistant
Professor of Orthopedic Surgery and Pediatrics at the University
Q: Dr. Dutkowsky, let's begin at the beginning. Who first discovered
x-rays and why were they given that name?
A: The German physicist Wilhelm K. Roentgen discovered them way
back in 1895. During one of his experiments, he noticed that radiation
not only penetrated through the skin so he could see deeper structures
like bone tissues, but it also produced phosphorescence or light.
Because he didn't really know what these mysterious rays were, he
named them "X" rays. Today, we know that x- radiation
is all around us-in the atmosphere, in the ground beneath our feet,
and even in our own bodies. We're all radioactive, you know. And
it has nothing to do with what we eat or drink-it's just the way
the good Lord put us together.
Q: Since our readers are interested in scoliosis x-rays, would
you tell us how much radiation is produced by a scoliosis x-ray
compared with other sources of radiation.
A: To answer that question, let's first talk about how radiation
is measured. The standard unit of radiation is called a "rad."
For measurement purposes, we usually divide a rad into thousandths,
which we call "millirads." In other words, 1/l000th of
a rad equals one millirad. Now, to put that into perspective, consider
a few figures:
Q: That's fascinating, but what about the radiation from a scoliosis
- If you stayed outdoors all year round in New York City, you'd get
90 millirads of radiation.
- If you stayed in a brick building 24 hours a day for a year in New
York City, you'd get 140 millirads.
- If you live outside the fence of a nuclear power plant, the U.S.
government would allow you to get 125 millirads per quarter, or
500 millirads per year.
- If you have a dental x-ray, you'd get 1,000 millirads.
A: If a young girl has a scoliosis x-ray exam, comprised of one
PA (posterior- anterior view, or back to front) x-ray plus one lateral
(side view) x-ray, and assuming preventive measures have been taken
to protect her breasts, her breast tissue would receive a total
of 10 millirads.
Q: Clearly, the amount of radiation from one scoliosis x-ray
isn't very much. But as everyone knows, x-radiation can alter tissue
and destroy it. So what preventive measures do doctors use to avoid
A: The first preventive measure is to avoid x-radiation whenever
possible. How do we do that? Well, during the course of treatment,
a doctor may use a scoliometer or other non-imaging method to monitor
the patient's curve. Unfortunately, though, devices like the Scoliometer
cannot give us exact information about a curvature; only an x-ray
can provide us with an extremely accurate picture of a curvature.
And in certain instances, when the patient is seen for the first
time and shows signs of scoliosis, or later on if his or her curve
has progressed, a doctor may need to x- ray the patient in order
to determine the precise nature and degree of the curve.
Q: In those instances when an x-ray cannot be avoided, what
do doctors do to lessen a patient's exposure to radiation?
A: First, let me tell you what doctors have done in the past several
years. To begin with, they have increased and standardized the distance
of the patient from the x-ray machine. Patients now stand six feet
from the machine, which automatically cuts down x-radiation exposure.
Secondly, they've reversed the position of the patient who must
have standing x-rays. Instead of having patients face the machine,
which allowed x-radiation to enter sensitive breast tissue first,
we now turn them around so their backs face the machine. By doing
this, the spine and ribs absorb much of the radiation before it
reaches the breast.
Q: What else can be done?
A: Doctors use a variety of lead shields that block roughly 99 percent
of the radiation generated via an x-ray machine. For young girls,
whose breast tissue is the most sensitive to radiation, we use breast
shields. Made of lead and covered with heavy cloth, the shield looks
a lot like an apron and covers the breast area during x-radiation.
When necessary, we also use lead shields that protect the female's
pelvic region where reproductive organs are located. For young boys,
we use lead shields for the gonadal area. In addition, all modern
x-ray machines have lead shields built right into them so that a
narrow x-ray beam is produced minimizing exposure.
Q: Since today's x-ray machines already contain lead shields
for protection against radiation, is it necessary to use the breast
and/or gonadal shields as well?
A: By using the lead aprons for breasts and/or gonads, you're adding
another measure of safety. At most scoliosis clinics, using these
aprons is a standard procedure.
Q: We've heard about something called "rare earth screens."
What are they and what do they do?
A: I'm glad you brought that up, cause that's a way that we lessen
x-radiation exposure. Placed on each side an x-ray film, rare earth
screens produce more light; you can use fewer x-rays to get the
same picture. For that reason, all scoliosis clinics today should
use rare earth screens.
Q: Even with all the preventive measures now being used, particularly
those that protect sensitive breast tissue, what is the risk of
breast cancer in young girls who've had scoliosis x-ray exams?
A: We've made a lot of progress in that area, too. In 1979, Dr.
Clyde Nash did a study indicating that the typical female adolescent
with scoliosis would undergo 22 x-ray exams during the course of
treatment. Due to those x-rays, he estimated the risk of breast
cancer would increase 110 percent . In my most recent study, which
takes into account the many preventive measures which I've already
mentioned, we've found that the risk has been lowered to .22 percent,
or roughly a fourth of one percent. In other words, assuming that
22 radiographic examinations are performed over the course of scoliosis
treatment-a greater number of x-rays than one would routinely receive
today-our findings reveal that the increased relative risk of breast
cancer is roughly two breast cancers per million women examined
per year beginning at age 35. That's an extremely small number considering
that the risk of a woman getting breast cancer in her lifetime in
the United States is one out of eleven.
Q: Even though your figures are relatively reassuring, we all
want to try to protect ourselves from radiation as much as possible.
Any other recommendations?
A: When patients have to have an x- ray, they should ask questions
about the equipment and procedures. Remember, patients have the
right to demand any or all of the preventive measures I've mentioned.
I believe that the patient's body is ultimately his or her responsibility.
The more you know about the care you're getting, the more informed
and comfortable you'll be, and that helps doctors do their jobs.
Most if not all scoliosis clinics will be using the procedures I've
mentioned, but it never hurts to ask questions to reassure yourself.
You'll feel better about what's being done.
Q: What about the future? Are other devices in the works?
A: The best "replacement" technology will probably be
magnetic resonance imaging or MRI; it doesn't use any radiation
at all to get a picture of the inside of the human body. Simply
explained, it's a magnetic device that's used with a computer to
provide exquisitely detailed images. If scientists can figure out
how to make it less expensive, more available, and faster at developing
images, I suspect it eventually will be the ultimate tool.
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