Part 1. The Key Action
The news from this book is good news. Knowing that the major cause of a serious disease is preventable represents an enormous step toward controlling the number of cases of the disease.
There is simply no doubt that past irradiation of breasts accounts for a large share of recent, current, and future breast-cancer in the USA (and almost certainly, in Europe). Some people will prefer to debate the exact size of the share (when exactitude is impossible), rather than to help eliminate unnecessary amounts of current and future breast-irradiation.
The exact share for which ionizing radiation is responsible will be irrelevant to people who care about preventing this disease. Can people really argue that preventive action is worthwhile if radiation's share is 75 %, but not worthwhile if the share is 50 % ? Indeed, could people argue against action if radiation's share were 25 % ?
The list of certainties at the end of Chapter 41 means that every action which reduces unnecessary breast-irradiation is guaranteed to prevent a share of future breast-cancers which would otherwise occur. We doubt very much that the same statement can be made today about any other focus of action.Part 2. Target: Unnecessarily High Frequencies and Doses
The target of eliminating unnecessarily high frequencies and doses in breast-irradiation is very different from eliminating or refusing the medical procedures themselves. Dr. Joel Gray (of the Mayo Clinic), who is certainly no "enemy" of radiology and nuclear medicine, acknowledged the difference in 1984 when he described offices which won't tell patients the expected radiation dose:
My feeling is that if they won't tell you, they don't know, and if they don't know, they could be among the facilities delivering a hundred times the necessary dose (Gray 1984, p.96 --- also cited in Chapter 28).
Do such horrible practices really occur in the post-1960 period? Indeed they do. The U.S. Bureau of Radiological Health did a survey, published in 1977, of x-ray doses for extremely common diagnostic procedures at hundreds of medical institutions. The variation in doses is confirmed by the data in the Variation In Dose box below
We are not currently knowledgeable about the situation in radionuclide usage.
The Fallacy Which Promotes Careless Over-Dosing
What accounts for the use at some places of radiation doses which are 5, 10, 20, or even 100 times higher than necessary? It is not difficult to measure entrance doses. And it is not difficult to eliminate unnecessarily high doses (see below). We believe the principal cause of unnecessarily high doses is the mistaken belief that there is a "safe" dose. The mistaken claim that low doses are harmless is usually followed by the mistaken claim that "repair" takes care of injury from low doses. Reporters in the major media tell us that, even today, they continue to hear these twin claims from some very influential people.
Entrance Dose in Milli-Roentgens (mR) Number Examination of Mean Standard Highest Lowest Institutions value Deviation Dose Dose *
1,433 Chest PA 23 29 2,300 3 126 Skull LAT 270 343 2,700 13 491 K.U.B. or 562 341 2,900 22 Abdomen AP 95 Retrograde 594 282 1,400 93 Pyelogram AP 52 Thoracic Spine AP 690 585 3,200 64 210 Cervical Spine AP 228 299 2,600 7 634 Lumbo-Sacral 792 545 5,500 11 Spine AP 31 Full-Spine 291 150 700 50 70 Feet 210 306 2,000 29 1,408 Dental Bitewing 650 727 6,800 68 759 Dental Periapical 644 696 7,500 75
Repair of DNA damage, including single-strand breaks, most certainly does occur. Every day, more than 10,000 DNA-repairs are made in every cell. The cell copes quite well with DNA damage induced by the free radicals which, due to normal cellular activities, are chronically present. However, ionizing radiation does more to cells than producing some routine free radicals.
The particle-tracks of ionizing radiation can do what no toxic chemical agent can do: Each track can deposit abnormally large amounts of energy in very concentrated areas near or within the genetic molecules. This is not speculation --- this is fact. And because of this unique property, each track can inflict complex (non-routine) lesions which the cell is unable to repair, no matter how much time is available. Such unrepaired and misrepaired genetic lesions are not speculative --- they include well-observed radiation-induced double-strand breaks, "locally multiply damaged sites," and enduring chromosome lesions of a great variety.
Observations of enduring, radiation-induced chromosome lesions are not limited to human cells irradiated in vitro. Such observations include human cells irradiated in vivo --- for instance, in living A-bomb survivors (Kodama and colleagues 1993) and in living nuclear dockyard workers exposed very slowly to less than 5 extra rems per year (Evans 1979). Moreover, persistence of a convincing chromosome dose-response for 40 years in the A-bomb survivors (Kodama 1993) shows that not all cells, genetically damaged by radiation, are removed by failure to reproduce. Definitely not. The combined teams of RERF scientists and Lawrence Livermore National Lab scientists were quite elated to be able to demonstrate the dose-response in A-bomb survivors 40 years after the bombing.
We and others (such as John Ward and Keith Baverstock) are not saying that all radiation-induced lesions are unrepairable and misrepaired. Far from it. But we and Ward and Baverstock are saying that the fraction which is unrepairable and misrepaired accounts for the observed effects of exposure to ionizing radiation. And no matter how low the radiation dose, or how slowly it is delivered, a fraction of the radiation-induced lesions will be unrepairable or misrepaired.
This is a powerful basis for saying that "repair" can not and does not provide any safe dose (Gofman 1990, p.18-2; Ward 1991, p.385-386; Baverstock 1991, p.384). Moreover, we have shown how mainstream human evidence confirms the logic and provides proof that there is no safe dose or dose-rate with respect to radiation-induced cancer (Gofman 1990, Chapters 18-21, 32, 33).
This book reports many of the mistaken assurances, given in the past to medical patients and professionals alike, that high doses of radiation were harmless. Now, everyone agrees those assurances were mistaken. Yet today, the same sort of ignorance and wishful thinking produce the same mistaken assurances --- about low doses. Reality: There is no safe dose or dose-rate. All doses matter --- roughly in proportion to their magnitude.
Real-World Cooperation between Radiologists and Physicists
Spectacular dose-reduction in medical irradiation has been achieved --- whenever people stop buying the safe-dose fallacy and make up their minds to get medical procedures done with the least amount of radiation. This book has already described some examples:
- More than a 50-fold reduction in breast-dose, demonstrated as achievable in management of curvature of the spine (Chapter 21, Part 2).
- More than a 30-fold reduction in breast-dose from mammography, when 1970 doses are compared with current doses (Chapter 28, Part 2).
- Substantial reduction in doses from fluoroscopy, with no loss of quality in diagnostic images (Chapter 32, Part 4).
The Canadian team of radiation physicists, discussed in Chapter 32 with regard to fluoroscopy, also worked with radiologists in Ontario to reduce unnecessarily high doses from making x-ray films. The remarkable results are reported in Taylor 1979, Johns and Cunningham 1983, and Gofman/O'Connor 1985. The box below shows some of the results. Johns and Cunningham state the following, in the fourth edition of their classic book, The Physics of Radiology (1983, p.557):
We have evidence (Taylor, 1979) that the dose from diagnostic radiology can be reduced by a factor of at least 3 with a little work and by a factor of 10 or more if all conditions are optimized.
Examination Minimum Exposure Average Dose Used (mR) Used (mR) in 1979
Skull Lateral 100 265 Cervical Spine AP 90 140 Thoracic Spine AP 260 460 Chest PA 8 25 Lumbar Spine AP 180 620 Lumbar Spine Lateral 500 2,445 Abdomen AP (K.U.B.) 190 530 Intravenous Pyelogram 150 600
Kenneth Taylor and colleagues achieved their results in busy x-ray facilities with whatever equipment the facility already had. No major purchases of new equipment were involved. For example, some facilities were using an entrance-dose three times higher than necessary because of poor processing of the exposed films. In such cases, Taylor and colleagues proved that a three-fold reduction in radiation dose was achievable just by paying attention to the correct chemistry and conditions to process the exposed films. Taylor and colleagues also showed that different combinations of screen and film led to a variation in the required exposure by a factor of 6. Attention to the proper choices was another route to big reductions in dose. Most importantly, the radiologists did not perceive any decrease in the quality of the diagnostic information at lower doses.
It is a credit to the Ontario radiologists that they invited Taylor's teams into their facilities. The result is a beautiful demonstration of what cooperating physicians and physicists can achieve, when motivated.
How Much Attention to Dose Is Given by Non-Radiologic Offices?
The evidence (above) is that unnecessarily high radiation doses occur even in some offices specializing in radiology. If some of them are using doses much higher than needed, then what is happening in the offices of non-radiologists? We have shown that there is widespread use --- today --- of both x-ray and fluoroscopy machines outside of radiology offices:
- In chiropracty (Chapter 22).
- In surgery, especially cardiac procedures. Because of high radiation doses, the FDA's Center for Devices and Radiological Health issued a Public Health Advisory in September 1994 (Chapter 29).
- In offices of cardiology, urology, neurology, and other specialties (Chapter 32, Part 5).
- In intensive care units (Chapter 37, Part 2). And in hospital rooms, with use of bedside fluoroscopes.
- In offices of unspecified type. On December 9, 1990, the Associated Press reported: "In recent years, many doctors have purchased x-ray and ultrasound machines so that they can take diagnostic images in their offices" (Assoc. Press, Dec. 9, 1990). The report was based on a study by Dr. Bruce J. Hillman at the University of Arizona.
The Issue of Unnecessary Frequency
Wherever the fallacy of "safe-dose" exists, there will be a tendency to take x-rays more often than needed. And the tendency is certainly fortified by legal wrangles over insurance claims and disability claims and malpractice claims.Part 3. Two Approaches Not Recommended by Us
The thesis of this book is that breast-irradiation is a major, proven, preventable cause of breast-cancer. The evidence is overwhelming, and can not be denied even by those who will challenge the size of the share.
Therefore, we recommend against excessive deference to those who say that action on the thesis ought to be postponed --- while everyone waits for some "blue ribbon commission" to bless such action, or waits for "more studies."
The studies which establish the role of ionizing radiation in breast-cancer causation have been done. Many of them are flagged by " # " in our Reference section. If the response to paying for those studies (almost entirely with hard-earned tax-dollars) is to throw away the results and start all over again, preventable breast-cancers will surely blossom forth for many more decades. Why did anyone do the studies in the first place, if we plan not to use the information gleaned?
Many citizens will say, "Elimination of unnecessary breast-irradiation is a government function --- not something we should attempt." To such citizens, we say "Think again." There are segments of the U.S. government which continue to press hard for lenient limits on the radiation doses which may be imposed on the public by nuclear pollution. They are the main sponsors of the safe-dose fallacy. And they are far more powerful than some individuals in the FDA's Center for Devices and Radiological Health, who seem really to have protection of public health at heart.
Counting on government to do the right thing is very, very risky. Pressing the government in the right direction consumes a lot of effort --- effort which is likely to be far more effective if it is directed at the media, at the medical schools, and at the physicians who "order" breast-irradiating procedures when they do not even know the dose.Part 4. Several "Do-able" Steps, Starting Now
Whenever the topics of radiation and breast-cancer are mentioned in one breath, we find that most people expect to hear about mammography. But mammography is certainly not the focus of this book. Mammography does nothing at all to prevent breast-cancer.
Prevention is our focus. The finding of our study points directly to a key preventive action: Eliminating unnecessarily high frequencies and doses in breast-irradiation. How can readers achieve that goal?
- Suggestion One: Informing the Media
Some medical journals and most of the mass media have been perpetrating a major fallacy about the breast-cancer problem. Most commonly, they list "risk-factors" for breast-cancer without even mentioning ionizing radiation. Or sometimes they assert that there is no proven cause of breast-cancer. For example, an article on breast-cancer in Parade Magazine (September 11, 1994, at page 27) said:
Can we find the cause? One theory on the cause of breast cancer holds that environmental toxins --- both man-made and natural poisons --- are, in part, to blame. However, the proof eludes scientists. A high fat diet has been pointed to as another possible cause. Some believe that pesticides or chemicals that may be stored in the fatty tissue of meat or fish or that are otherwise ingested may be associated with increased risk. Again, no real proof.
How does it happen that a proven cause --- ionizing radiation --- is not even mentioned?
People who are organizing to prevent breast-cancer surely recognize that misinformation can kill, and that ignorant commentary on this major health problem must be challenged. For starters, we suggest that breast-cancer activists (including any who are within the medical system) adopt the goal of preventing more of such ignorant commentary, by systematically acquainting editors at all the major media with the list of certainties at the end of Chapter 41.
- Suggestion Two: Validating the Expectation of Information
Many people, men and women, have told us: "I don't feel I can challenge the doctor who pooh-poohs the hazards of radiation. Most of them tell me that x-ray exams are comparable to taking a plane trip or a sun-bath. Some physicians even seem angry about my raising the question. I'm afraid to ask whether they are sending me and my children to an x-ray place which measures the doses, or if they know the doses when they do the x-rays themselves. They get defensive. Very defensive. And so I don't know how to do the right thing for myself and my family."
The frequency of such comments tells us two things:
(a) There are some physicians who were never exposed to real education on ionizing radiation. In terms of radiation risk, airplane comparisons are valid only for a few types of x-ray exams, and sun-bath comparisons are wrong because ultra-violet radiation does not reach internal organs. Diagnostic x-rays do.
(b) There are some physicians who were never trained to recognize their obligation to serve as "ombudsperson" for patients in the medical system. We adapt the term "ombudsperson" to mean physicians who inform themselves about perils for their patients elsewhere in the medical system, before they send their patients off to learn about such perils on their own --- the hard way.
In general, patients do not refer themselves to laboratories or to radiologic facilities. Who makes the decision that Radiology Office XYZ really is the one to which patients should be referred? Who should take the responsibility for ensuring that the patients do not receive 2-fold, or even 5-to-50-fold, more than the necessary radiation dose (see Part 2, above)?
Since family physicians, internists, surgeons, pediatricians, gynecologists, orthopedists, sports and occupational medical specialists, and others, are the ones who "order" the patients to have radiation exposures (including exposures from nuclear medicine), they are the ones who have the responsibility, as a minimum duty to their patients, to boycott facilities which can not at least tell them the expected radiation dose. We remind them of Dr. Joel Gray's warning (Part 2 of this chapter):
My feeling is that if they won't tell you, they don't know, and if they don't know, they could be among the facilities delivering a hundred times the necessary dose.
In medicine, failure to know and to record the dose of every agent administered to a patient is remarkable. And recording is not done only for the purpose of billing. It is done for better care of the patients, for better operation of the facility, and for a better chance of useful research.
It is patently unfair to expect the patients to find out if the radiology facility is one which makes a marvelous effort to measure its doses and to keep them to the minimum required for obtaining useful medical information --- or whether it is not one of those. Patients are entitled to expect that the referring physicians can tell them just what they (the physicians) have done to ensure that unnecessary radiation doses are not occurring in the radiology facilities which they recommend.
Risk from One Exam vs. Aggregate Cancer-Toll from Millions of Exams
Why do the referring physicians not take the responsibility to find out? The answer can probably be traced to their medical education --- where this responsibility was probably never brought up. Some medical deans themselves may suffer from the "safe-dose" fallacy or the "same-as-an-airplane-trip" fallacy.
In reality, allowing unnecessary amounts of irradiation is harmful. The extra cancer-risk need not be high per exam in order for referring physicians to induce a very serious cancer-consequence from ordering millions of exams every year. We can believe that medical schools are doing their job on cancer-prevention when every graduate accepts the "ombudsperson" role with respect to seriously considering and minimizing doses when ordering exposures to radiation. After all, a prime rule for physicians is: "First, do no harm."
Meanwhile, advocates of breast-cancer prevention need to help patients resist intimidation when they ask about the expected breast-dose from procedures causing irradiation. Patients are not obliged to prove to the physician that they can interpret the information "correctly." In reality, the first step for patients is just to ascertain whether anyone in the medical system has bothered to know the dose, before the patients or their children are told to go take it.
Measurement of radiation entrance doses is neither difficult nor expensive, and referring physicians could even supply their patients with little self-stick "TLDs" (Thermo-Luminescent Dosimeters) as a reality-check on pre-exam dose-estimates. Indeed, about ten years ago, two radiologists in New York State tried to start a commercial service which would have enabled patients nationwide to measure their own doses during x-ray exams. They met with immense resistance from medical colleagues, and the idea collapsed.
- Suggestion Three: Meeting with Deans of Medical Schools
If women find that their physicians know virtually nothing about ionizing radiation and its role in breast-cancer causation, we would not suggest running away from them. Instead, it would be enormously more helpful if women would seek out the deans of our medical schools to discuss why training of physicians has been deficient in at least two ways:
Many graduates of medical school appear not to appreciate the proper role of physicians in preventing cancer (instead of just treating it).
Many graduates appear not to recognize their duty as "ombudsperson" for their patients within the medical system.
And the women must persevere until they achieve some meaningful action on the part of medical educators to remedy those deficiencies with regard to physicians-to-be. With regard to physicians-in-practice, they are generally required to take courses each year for "CME credits" (Continuing Medical Education). They are highly educable.
- Suggestion Four: A Cash Prize for Dose-Reduction
We are extremely impressed by the opportunities for reducing unnecessarily high levels of breast-irradiation (Part 2, above). With the exception of mammography, there is no reason to believe "It's already been achieved."
On the contrary.
- First, achievements of this nature tend to be temporary. An expert office which was a very low-dose place in 1985 can be a very high-dose place in 1995 --- if the personnel change. Keeping doses down requires continuous commitment and continuous checking by measurements.
- Second, many users of x-ray equipment operate outside of expert radiologic offices.
- Third, Kenneth Taylor and his colleagues did not think that a 3-fold reduction in typical diagnostic doses in radiologic offices was the maximum achievable. They thought that a 10-fold reduction could be achieved.
People concerned about preventing breast-cancer might think about how to establish a prize. Why not award a cash-prize to the radiologic office which develops and demonstrates exactly how to achieve a 3-fold reduction in average dose for the five procedures which presently cause the most breast-irradiation? A follow-on could be distribution of the "recipes" to every place where such procedures occur. The American College of Radiology, the Radiological Society of North America, the American Society of Radiologic Technologists, or all of them, might be approached for their ideas about this.
- Suggestion Five: Organizing Community Watchdog Groups
One of the most useful tasks, for people concerned about breast-cancer prevention, would be to form an on-going watchdog group in every community to "see to it" that radiation doses are measured (in radiologic and non-radiologic offices), that facilities can document their measurements, and that medical schools do a better job in educating past and future graduates about ionizing radiation and about their obligation to serve as "ombudspersons" for their patients with regard to radiation.
If the citizens who are concerned about breast-cancer prevention do not accept the task of watchdogs, then who will do it effectively? Not the government. Not business. Not the press.
This book has told the story of how past medical irradiation (with small contributions from natural radiation and from fall-out) has been responsible for hundreds of thousands of breast-cancers, with many more to be delivered in the future. A high priority of watchdog groups, in our opinion, should be to identify all of today's radiation exposure of breasts, and to see that every source of exposure is reduced as much as possible.
Watchdog groups can find ways to "get the job done" without imposing great costs on everyone. Taylor and co-workers have shown that large decrements in dose can be achieved (see Part 2) without large investments --- when people are motivated to do it. Watchdog groups can specialize in the motivation.
And in the friendly vigilance required.
The wisdom and virtues acquired by one generation never pass automatically to the next generation. The transfer requires "tender, loving attention." Problems, once fixed, seldom stay fixed. We are humans, after all, and it is so easy to become careless.
The Expanding Use of Radiation in Medicine
We have noted that the rates of x-ray examinations and nuclear medicine examinations, per thousand people, both have increased (Chapter 37). Is this cause for concern? In Chapter 28, Table 28-B illustrated a fundamental principle: If nearly everyone receives extra radiation, even low doses will induce a huge amount of cancer, in the aggregate. The menace is never just the size of an individual dose (in rads). It matters enormously how many people receive it (in person-rads). And the related principle is this: When large numbers of people are receiving extra radiation, very large aggregate benefits in health accrue even from small reductions in dose per exposure. So friendly vigilance can make a big difference.
Watchdogs need to think very seriously about proposed new uses of radiation (medical and other). Technology enthusiasts tend to assume that the benefits of their technology will vastly exceed their price (in health). Chapter 27, for example, shows how lucky we were that female children were getting shoes instead of sweaters fitted with the "help" of those very popular fluoroscopes. Chapter 28 shows how excessive use of mammography, without reducing the 1970 dose-levels, would have caused a breast-cancer disaster. And Chapter 31 shows how universal use of fluoroscopy in monthly "well-baby check-ups" also would have caused a breast-cancer disaster.
These "new uses" of radiation did not get fully adopted, but enough "new uses" did get adopted that we do have a breast-cancer problem today. Women and their families can depend on luck to prevent the problem from continuing in the future, or they can depend on "authorities" to provide the "tender, loving attention" --- or they can depend largely on their own watchdog abilities.
- Breast-Cancer Prevention: A Reality
In cancer-prevention, the latency period makes it impossible to equate preventive action today with observable benefits the day after tomorrow.
Nonetheless, the watchdog groups have a certainty to sustain their efforts. They can be certain that each reduction they achieve in breast-irradiation will prevent some of the future breast-cancers which would otherwise occur.
We urge all the citizens who are trying to prevent breast-cancer to make use of the knowledge that radiation is a major, proven, preventable cause of this disease.
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