Does mammography cause cancer? Interview with prof. Jerzy Walecki, a radiologist

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Electromagnetic radiation is harmful, mammography causes breast cancer, frequent ultrasound during pregnancy can harm the baby, especially when the doctor has old equipment in his office – patients scare each other. We asked prof. dr. hab. n. med. Jerzy Walecki, national consultant in the field of radiology and imaging diagnostics, chairman of the Medical Physics Committee of the Polish Academy of Sciences.

Agnieszka Sztyler-Turovsky: Professor, how is it with this radiation, should we be afraid of it or not?

Prof. dr hab. n. med. Jerzy Walecki: Do not be afraid when radiation concerns equipment controlled by Sanitary Inspection bodies and important clinical indications, i.e. situations when information about the patient’s disease and proper treatment require such diagnostics. Of course, I am talking mainly about X-rays with a wavelength of less than 100 nanometers. Long-wave radiation does not fit into the concept of ionizing radiation and there is no scientific evidence for its possible harmfulness.

Many people are afraid of even minimal doses of radiation and avoid, for example, chest X-rays, explaining: “I don’t smoke, so I don’t suspect that I may have lung cancer, and tuberculosis is not as common as it used to be.”

The chest x-ray, paradoxically, is one of the least burdensome studies. The effective dose is about 2 hundredths of a millisivert, so it corresponds to 1/120 of the annual dose obtained from natural sources. It’s three days outside, so the opinion about the harmfulness of this study cannot be taken seriously in any way. After all, we do not do it for the sake of beauty, but to detect, for example, extensive inflammation or a lesion that can be removed in time. In addition, the basis for taking e.g. a chest picture or a mammography is a referral from a doctor. And it is up to the doctor to assess what is a greater cost: whether the patient has taken a certain dose of radiation, or if the patient has not diagnosed, for example, a bone fracture, inflammatory infiltrate or a neoplastic lesion, and, as a consequence, not starting treatment.

The answer seems obvious.

Yes. I strongly emphasize: the doses of radiation that the patient takes during a single examination (I’m not talking about embryos and fetuses in the organogenesis phase) are not the ones to be afraid of. Unless someone was taking an x-ray all day long. The dose we take during one test is similar to a few days’ dose of the so-called background, that is, the dose of radiation that we would take in a few days from the atmosphere, being outdoors.

So scaring women that a mammogram repeated every two years is asking for a breast tumor is unjustified?

It is ridiculous and dangerous. Mammography performed in the so-called with the screening program [jg1] there are no threats. I am deeply convinced of this. I think the said opinion is about the older generation of mammographs. A study commissioned by the FDA (American Food and Drug Administration – ed.) Showed an incomparably greater benefit from screening cancer detection than the alleged breast cancer induction by x-ray. Moreover, there is no methodology of a population study that would allow to prove with certainty that the cancer was induced by the radiation dose taken by the patient during the study, and did not result from the statistically predicted morbidity.

This ambiguity is of concern to many patients.

Large doses of radiation are carcinogenic and there is indeed a so-called induction of tumors by doses of ionizing radiation, commonly known as x-rays, but this only happens when these doses are significant. There have been reports of cases where, after intensive radiotherapy, i.e. irradiation in the case of a bone tumor, there was a rapid relapse or even development of the tumor in the vicinity at the resection site.

And, unfortunately, for each person the dose inducing a tumor may be different?

We never fully know what factors may be the so-called trigger, that is, the trigger factor. There are indeed studies that say that having a low percentage of mammography too often may account for the appearance of cancer in a woman who was not diagnosed with cancer at the time of diagnosis. I mentioned above that these tests had a significant handicap – it is not known whether this tumor developed because the woman had had several mammograms over the last year, or if she had already had a tumor at a very early stage, and has only developed in the meantime.

There is no hard evidence that mammography caused this tumor?

Not. Therefore, limiting the performance of mammographic diagnostics, an attempt to undermine or threaten women with the danger of these tests gives dramatic results. It moves women away from preventive diagnostics. It has been proven that because of early detection, women participating in mammography screening programs have a significantly reduced risk of dying from breast cancer. If we diagnose more often, we start treatment faster.

What radiation dose does a woman expose during such an examination?

Really small, because it is about 1/6 of the annual dose taken from the atmosphere.

Except that the dose from the atmosphere is distributed throughout the body, and here it is directed only to the breasts.

Yes, but this is a pretty big area anyway, because it’s not a point-directed dose. In addition, sensitivity to ionizing radiation decreases with age. In a 60-year-old woman, for example, it is 10 times smaller than in a 30-year-old woman.

Apparently, mammography is being abandoned, it is to be replaced by magnetic resonance imaging, the examination is more expensive, but more accurate?

I think that, for now, MRI, although it has enormous advantages, because it has high sensitivity and allows for examination with the administration of a contrast agent, will not replace mammography. Because such possibilities – the use of contrast, already have a new generation of digital mammographs.

Today, MR mammography can be treated as a method of in-depth diagnostics, although the real deepening of imaging diagnostics is a biopsy.

Mammographs equipped with this option are already available in Poland?

Of course, there are fewer of them than the traditional ones, but they already are.

You mentioned the harmfulness of radiation in the case of embryos and fetuses in the phase of organogenesis. How is it with x-rays in pregnant women?

The first trimester is the most dangerous. The fetus is in the period of organogenesis, that is, in the stage of organ formation, even the dose of a single test is harmful. The organs are just being formed and in this phase they are very sensitive to radiation, although we are talking about low doses. Of course, there are strict regulations and procedures on when to perform an X-ray in a pregnant woman and what safeguards should be used. Unfortunately, we know many clinical situations where examination of a pregnant woman must be performed, for example, injuries.

What if the woman doesn’t know she’s pregnant?

If, for example, she had an X-ray of the area of ​​her kidneys or spine, and she did not know that she was pregnant, e.g. in the first two weeks, then when she realized that she was pregnant, she should report to the diagnostic facility where she was performed. picture. There are special procedures in place to deal with such cases and the woman will be informed of them. The dose taken by the zygote or the embryo is calculated and the risk to the fetus is estimated. He deals with this, among others National Center for Radiological Protection.

And how is the ultrasound examination? It is completely safe?

Yes. There are no proven side effects of the ultrasound wave, of course I am talking about the frequency and length of the wave that is used in diagnostic equipment.

Patients fear that doctors in private clinics cannot afford to buy great equipment, so they bring “scrap” from abroad, and testing with such a device may be dangerous.

I would like to reassure patients: devices in hospitals and private offices undergo technical tests once a year, which allow or not the equipment for use.

And yet it happens that in private offices we hear from doctors: “Please come to the hospital for an ultrasound, I have better equipment there”.

Yes, but the point is not that the examination using the equipment in the office will be harmful to the patient, but that the hospital may have equipment that will provide better diagnostics, e.g. a monitor with a better resolution. Just as I can say that the equipment in the hospital in which we are talking now is better than that in the hospital or office at ul. X. Technically, however, that equipment is also normal.

Since imaging tests are so harmless, maybe we should do them on our own initiative, if possible, without waiting for a refund from the National Health Fund?

It is not necessary (except for breast cancer screening) to regularly check each organ for an early lesion. For a diagnostic imaging test, there must be an indication, e.g. a suspicion of a disease in combination with e.g. risk factors such as the patient’s age, genetic load or being in a contaminated environment, for example.

Many private hospitals are beginning to offer patients the so-called packages for busy people – we go to the hospital for a day and examine us from head to toe.

I believe that there is no substitute for regular visits to the GP and the ability to see yourself and listen to your body.

Oh, it’s easy to get hypochondria then?

Unfortunately yes. However, I am not talking about hypochondria, but about a certain vigilance. Diseases really make themselves felt early on with various symptoms. When we rely on the aforementioned package, it is easy to lull our vigilance. And it may happen that, reassured by good results, we postpone thinking about our health for a year, until the next package examination is due. Meanwhile, something is starting to happen. It may happen, for example, that a man in April has excellent results of the prostate gland examination, ignores the problems on duty and in December already has an advanced shift. I must say clearly that such a package diagnostics is commendable, especially in some diseases, e.g. cardiovascular.

We know that the National Health Fund does not reimburse everything, and imposes restrictions on doctors in the issue of referrals. We are tempted not to stop at the ultrasound commissioned by us and to deepen diagnostics in commercial institutions.

I believe that such hikes based on Google knowledge are pointless, with all due respect to the Internet. I would like to emphasize that imaging techniques require the selection of methods and their coordination. Carrying out research on such a basis that something can still be done somewhere is absurd. If we have a health problem and our GP suspects something more serious, they should refer us to a specialist who knows more about a given condition; for him to decide on further diagnostics. Patients grab all the information

about where they can diagnose themselves privately, and by the way, sometimes fall prey to the clever marketing of various companies and lose money.

Is the advancement of imaging technology making the physician’s experience less relevant, or the contrary?

The medical experience is still crucial. If we assume that the diagnostic equipment meets all technical conditions, then the main element responsible for a possible diagnostic error is the doctor. Because even if, thanks to the equipment, we find out that the detected change is not half a centimeter, but three and a half millimeters, it is still crucial to describe its topography, i.e. location – to determine whether it suggests a cancer process or not. There are dozens of features that an experienced radiologist will see or not. In addition, it is crucial to propose a method that will deepen the diagnosis. The radiologist’s experience is not losing its importance, and even gains, because it has to keep up with the increasing technological possibilities.

Still no single perfect imaging technique? Each of the methods has both advantages and disadvantages?

Each method has its limitations. If, for example, we are dealing with cholelithiasis, it will be a mistake to perform magnetic resonance imaging for the patient. The method of choice is ultrasound. And when it comes to intracranial aneurysm pathology, we choose CT angiography (vein imaging with computed tomography – ed.) [Jg2], and not, for example, PET [jg3] (positron emission tomography – ed.). We have great techniques today, so the trick is to choose the right ones. An experienced radiologist should know which technique is most effective in a given pathology group.

What about an inexperienced radiologist who starts his profession?

There are several guidelines for diagnostic practice standards. These are mainly the procedures for performing tests with the use of ionizing radiation developed by a team of experts appointed by the Minister of Health. There is also a position entitled “Guidelines for Doctors Referral to Imaging Tests.” This is a translation of the guidelines of the British Royal College of Radiologists, the most important European radiological association.

As a national consultant in the field of radiology and imaging diagnostics, I deal with, inter alia, planning to equip Poland with the best diagnostic equipment. And also examining and training radiologists, because there must not be a situation where there are more great apparatuses than experts. The point is to train radiologists quickly and in a modern way, to keep up with the great possibilities of today’s equipment. The training program outside CMKP [jg4] (Medical Center for Postgraduate Education – ed.) Is carried out by individual medical universities and the Polish Medical Radiological Society. This is nearly 60 courses a year, during which we train young radiologists, among others from the issues discussed above.

What is the most problematic for radiologists today, are there, for example, organs that are particularly difficult to assess?

The pancreas is undoubtedly such an area that requires extraordinary diagnostic vigilance. Changes in this organ are usually small and when we see them they are usually in an advanced stage. It is constantly difficult to diagnose the musculoskeletal system

The diagnostics of the prostate gland is also a challenge, although more and more imaging techniques are introduced, e.g. in PET, new membrane markers have emerged. And only the compilation of tests with several techniques gives a reliable result. For example, in MRI (magnetic resonance imaging – ed.), Such multiparameter tests [jg5], which were introduced in the guidelines of the European Society of Urology under the name PIRATS, are already referred to as the standard.

In Poland, they are already available, but still not in all centers. We encounter diagnostic problems everywhere, radiology is a fascinating discipline, but difficult at the same time. Paradoxically, the introduction of new technologies and the development of the current ones lead to an increase in the recognition of certain pathologies, but there are still diseases that can be described perfectly with the aphorism “old diseases – new problems”.

Will there come a time when we only need an imaging examination and a description of an experienced radiologist and we will be able to do without a biopsy and other unpleasant, invasive examinations?

The biopsy will probably remain an in-depth diagnosis. The imaging examination shows the existence of the lesion, its extent, the existence of infiltration, and metastatic foci, but still does not decide about the histopathological nature of the lesions. Imaging methods will not replace histopathological, immunohistochemical and genetic tests. On the other hand, it is the CT or MR examination that will show, for example, an increased volume of the vascular bed in the process of neoangiogenesis, i.e. the formation of pathological vessels, which is one of the evidence of the malignancy of the lesion. All this can be seen only in a living organism, and not on the basis of a piece of tissue.

A spectacular example of the use of imaging techniques is the assessment of ischemic changes in the brain, where the assessment concerns structural changes (ischemic focus), functional changes (blood flow through the placenta [JW1] of the brain vessels), as well as methods of interventional neuroradiology for the treatment of ischemic changes.

Similarly, histopathological examination or CT or MRI will not replace the assessment of tissue metabolism in PET or the appearance of abnormal metabolites in MR spectroscopy.

Imaging techniques are part of the comprehensive assessment of most diseases and I would like to return to the previous topic: the art of clinical diagnostics is the ability to select appropriate imaging and non-imaging methods in diagnostic procedures.

With such advancement in technology and knowledge of radiologists, are there still frequent misdiagnoses?

Unfortunately, paradoxically with the development of technology, there are no less errors. There are e.g. errors with the so-called false positive diagnoses, that is, diagnoses of changes that do not exist. This high technology often generates such accurate images that the slightest changes are visible, which are not always a symptom of the disease. Errors also generate situations when, for example, the patient moves and the image is not sharp enough. They are also due to, for example, lack of sufficient knowledge or experience. I must emphasize that there would be half as many errors if referrals for research were written by the referrals reliably. If the clinician would always share his knowledge with the radiologist

For example, in the patient’s medical history and on the referral, he wrote that he was particularly concerned about a certain place in a given organ, so he asked to evaluate this organ in particular – the error usually has several authors.

Radiology is strongly related to telemedicine today?

Telemedicine has an established place in radiology. The beginnings, i.e. the transmission of research results using a digital method, date back to the 70s, when after the Skopje earthquake, X-rays were described by experts in the USA. Also from an economic point of view, the possibility of sending test results is a great method, because a server and a good monitor are enough, and you can significantly reduce the costs of doctors’ on-call duty. An examination performed at night can be immediately assessed by a doctor in another country during the day, in our terminology we call it following the sun. The times of day and night change, and another team of doctors is still working on the same task. The dangers of this method include such that if the doctor describing the examination has no contact with the clinic and does not know the details related to the patient’s entire medical history, does not know the details of the problem and its dynamics, the description is therefore much poorer, and the doctor who continues the diagnosis does not “set” the examination under such the angle at which the technician should make them. An example is the situation from a few weeks ago: a doctor from one European country described a German examination of the posterior skull structures in a six-year-old child who had a tumor of the cerebellopontine angle. The test was performed as standard, thick layers; they had to be performed twice – with and without contrast agent. This was not done because the examining physician had no online contact with the technician performing the examination, so there was no complete clinical picture.

When several years ago I was implementing the EU teleradiology program with the Department of Neurosurgery of the Polish Academy of Sciences and we were diagnosing patients from several Masovian hospitals within an hour, I could not imagine the scale of the possibilities of these disciplines. Teleradiology makes it easier for doctors, but also a routine threat. Therefore, a radiologist should always remember that his job is not to look at pictures, but very responsible clinical work. If it is not done correctly, it may be too late in a few months.

What apart from technology is the greatest achievement of imaging diagnostics, and what is its future?

A new way of thinking about imaging diagnostics. As a matter of fact, the frontier of seeing the human eye is over, but we, radiologists, apart from structural imaging, associated with X-rays, have more and more possibilities to assess the microstructural, biochemical and metabolic level of the cell. What happens, for example, at the level of metabolites, can be seen, for example, in the intensity of the spectra of certain chemical compounds. We can already assess the cell density / MRI /, or the chemical density of the tissue, for example in spectroscopy, add to this PET (positron emission tomography – ed.), Which [jg6] assesses the tissue metabolism. The future is multimodal radiology, a fusion of many methods that together will give a complete picture – from the structure of an organ to its function. This will finally bring us the appropriate diagnostic efficiency!

10 SYMPTOMS OF THE HIDDEN CANCER

Prof. dr. hab. n. med. Jerzy Walecki, national consultant in the field of radiology and diagnostic imaging, chairman of the Medical Physics Committee of the Polish Academy of Sciences.