Growth in dental use of CT machines raises radiation exposures dramatically
by Alex Roslin
The Georgia Straight
August 14, 2013
CAROLE-ANNE STANWAY HAD lived
with blinding headaches for 17 years before she decided enough was enough.
The grandmother of five in Kelowna
finally asked her doctor for an MRI to see what was wrong. He refused to give
her a referral, saying the headaches were just from tension. He had put her on
Tylenol 3 and antidepressants, but those hadn’t helped.
Stanway got an MRI done privately
anyway, at a cost of $2,700. The result: she had three meningiomas, a type of
brain tumour.
The good news was the tumours weren’t
cancerous. The bad news was the specialist didn’t want to remove them unless
they became cancerous because of the risk of brain damage.
Stanway put up with the headaches for
five more years until, in 2002, they and other health problems forced her to
stop working as an assistant in a medical office. She’s been on disability
leave ever since.
Buffet of Pain Drugs
Buffet of Pain Drugs
She has been prescribed a buffet of
pain drugs, which, along with noninsured medical procedures and travel to see
specialists, have drained her savings. The drugs reduced the pain for a while,
but her body quickly got used to them. Then they didn’t help anymore.
She stopped taking the pain meds five
years ago after they started to cause her kidney problems. Some of the drugs
also gave her severe nausea. But she’s still on the antidepressants. “Chronic
pain is difficult to deal with otherwise,” she said in a phone interview from
her apartment.
A few months ago, her eyes started
moving uncontrollably while she was reading, likely a side effect of
meningioma, which can cause optic problems.
Stanway said doctors don’t know what
caused her meningiomas, but she thinks dental X-rays are a possible culprit. “I
had a lot of dental work done when I was younger. As children, we received a
lot of radiation.”
In a study in the journal Cancer last
year, 1,433 people with meningioma were found to be two times more likely to
have had a “bitewing” dental X-ray as those without the illness. Those who
reported having a panorex scanning dental X-ray (which gives a two-dimensional
panoramic view of the mouth) before age 10 were 4.9 times more likely to have
meningioma.
Meningioma is the most common form of
primary brain tumour (tumours that start in the brain). Women get it more than
twice as often as men.
Other studies have linked dental
X-rays to thyroid cancer, breast cancer (in women who hadn’t worn a shielded
apron), saliva-gland tumours, and glioma (a cancerous type of brain and spinal
tumour).
Pregnant women who got a dental X-ray
were three times more likely to deliver a low-birth-weight baby (weighing less
than 2.5 kilograms), according to a 2004 study in the Journal of the
American Medical Association.
Dental X-rays are the most common way
Americans are exposed to human-made radiation, the 2012 Cancer study
said.
Yet despite growing awareness about
the risks of X-rays, radiation in many dental offices is actually rising.
That’s thanks to the explosive growth of 3-D cone-beam CT (computed tomography)
machines, which give off up to 60 times the radiation of a conventional dental
X-ray.
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