By Dr. W. Gifford Jones
February 4, 2007
Last week I reported on a study conducted by Peter Gotzsche (Stop Lying To Women About mammography), a leading Danish researcher. His study claimed there's no convincing evidence that annual mammograms decrease the risk of dying from breast cancer. But can repeated exposure to radiation cause breast cancer?
28 years ago I reported a shocking discovery. Some x-ray machines were exposing patients up to 60 X the amount of radiation necessary for some procedures. X-ray equipment was often old, others rarely calculated for radiation exposure, and some technologists were incompetent. This column did not win me friends. But it resulted in a crack down by the government.
However, regulation of equipment still didn't teach radiologists enough to know you don't mess around with nuclear engineers. A few years ago a nuclear engineer told me a story. He had asked a technologist how much radiation he was receiving from back x-rays. The reply, "the same as you would get from a two hour plane trip". Later, the engineer calculated it would take 1,120 plane trips to equal the amount he had received from these x-rays.
Nor did the radiologist know the answer. Later he called and said the exposure was 2.8 roentgens. Yet this nuclear engineer was only allowed exposure to 0.1 roentgens a year at the nuclear plant where he worked. Again he calculated it would require 28 years in the plant to receive the same dose as the exposure at the clinic.
I'm no nuclear engineer, but I recently felt similar frustration. I called several hospitals, talked to technicians and radiologists and asked "How much radiation do women receive from the average mammogram?"
I got tired of hearing, "It's the same amount as you would get from a Caribbean vacation". Or "It's a new machine and I don't know". Then when I asked what was the dose from their old machine, again "I don't know". I also called several hospitals and mammography units requesting specific data. Only two called back, providing scant and inadequate information.
Joel E Grey, an expert on radiation and formerly at the Mayo Clinic, says it's a mistake to compare a day in the sun at the beach to the penetrating photons of x-rays.
Dr. John Gofman, a well-known critic of excessive radiation exposure says, "the serious effects from minimal radiation doses are not imaginary, they are real."
Today's mammography technology is regulated to expose the breast to 0.2 roentgens. In 1972 one report estimated the older equipment delivered from 10 to 35 roentgens to the breast! This is why Dr. Gofman believes that 75 percent of today's breast cancers are due to excessive radiation doses in the past. Others contend this is nonsense.
Remember, radiation is like an elephant, it never forgets. Every roentgen you receive including dental, bone and other x-rays is added to the overall amount.
It is not the purpose of this or the previous column to persuade women not to have mammograms. Rather, it's to ensure women are informed patients about this routine procedure, and for everyone to guard against needless radiation. It can be done.
Remember, if you're patient most aches and pains get better with time. And never say to your doctor, "Can't you take an x-ray?" This is the same as waving a red flag in front of a bull. You will get one.
Beware of defensive x-rays. If a doctor believes the ankle isn't broken he often orders an x-ray anyway for fear of being sued for missing the diagnosis. Tell your doctor you don't want a defensive film done and be willing to sign that you assume this responsibility.
Find a dentist who uses good judgment in taking x-rays. We all need x-rays now and then. But get a second opinion if full mouth films are ordered every year.
Remember that procedures such as fluoroscopy and CT scans result in much larger doses of radiation than single ones.
The Health Department should provide everyone with a radiation card so dosage can be documented each time an x-ray is done. If radiologists don't know the exact dose they must find out. Surely this is the least patients can expect. I think it's reasonable to say this would save more lives than Canada's gun registry.
W. Gifford-Jones M.D is the pen name of Dr. Ken Walker graduate of Harvard. Dr. Walker's website is: Docgiff.com
My book, �90 + How I Got There� can be obtained by sending $19.95 to:
Giff Holdings, 525 Balliol St, Unit # 6,Toronto, Ontario, M4S 1E1Pre-2008 articles by Gifford Jones