Radiology in Breast Cancer Screening
Breast cancer affects one in 8 women in their lifetime. Although breast cancer is also seen in men, it is much less common. While the lifetime risk of developing breast cancer is 0.1% in men, this rate is 12-13% in women.
Due to the development of awareness about breast cancer, early diagnosis with screening methods and advances in treatment methods, deaths due to breast cancer show a significant decrease compared to previous years.
85% of breast cancers are seen in people who have not had a relative with breast cancer before. Therefore, the absence of this story in the family does not mean that the person will not have cancer.
Only 15% of patients with breast cancer have a relative in their family who have been diagnosed with breast cancer before. Since ovarian cancer can be inherited with genes similar to breast cancer, those with a relative with ovarian cancer in the family are at similar risk for breast cancer. For this reason, it is very important for those with a family history to consult a doctor and have regular check-ups.
The most important factor in lowering the mortality rate is the early diagnosis of breast cancer. When diagnosed early, 90-93% of patients regain their health.
Early diagnosis starts with regular control and breast examination. Radiological examinations are important imaging methods in early diagnosis.
Today, the recommended methods for early diagnosis are:
Breast self-examination at the end of the menstrual period from the age of 20 (once a month)
Clinical breast examination by a doctor from the age of 20-30 (every 1-3 years)
Clinical breast examination and mammography by a doctor from the age of 40 (annually)
Who Should Have Mammography?
Mammography is the most valuable method for radiological screening in patients with no complaints for breast cancer. Therefore, women over the age of 40 should have regular annual mammography screenings even if they do not have any complaints.
Apart from this, mammography can be performed after the age of 30-35 to aid diagnosis in patients with palpable mass, spontaneous bloody nipple discharge, spontaneous shrinkage in the nipple or breast skin, orange peel appearance on the breast skin, and similar findings.
How is mammography done?
Mammography is a method by which the radiology technician takes films of the breast from top to bottom – from inside to outside, by giving the breast to the appropriate position and using x-rays (radiation).
During the filming, a slight compression is applied to ensure that the patient does not move, the image is clearer, less radiation is given to the breast and that the breast can be thinned and better image. This compression takes only a few seconds and although it varies from person to person, it generally causes short-term and tolerable pain.
After the procedure, a total of 4 images, including 2 images of both breasts, are obtained. The images obtained are evaluated by the radiologist by projecting on a monitor or printing on films.
Who Should Mammography Evaluate?
Ideally, radiological imaging of the breast should be performed and evaluated by radiology specialists, especially those with high knowledge in this field. In the evaluation of breast imaging, it should be kept in mind that the quality of the devices, the qualified and well-trained radiology technician who will perform the imaging and position the breast properly, is very important for the correct diagnosis, as well as the experience of the doctor working in this field.
How Is Mammography Evaluated?
The radiologist first evaluates the normal breast structure on mammography images. There are milk glands, connective tissue and adipose tissue in varying proportions according to the person and age in the breast tissue. While adipose tissue is dark gray or nearly black in mammography, connective tissue and milk glands are white.
Cancer tissue is also seen in mammography as a white mass, deformation or condensation. Especially in cases where the breast tissue is more dense, it is difficult to choose the white color on a white background, so mammography is insufficient to detect cancer. This is the main reason why breast cancer cannot be detected (missed) on mammography. Therefore, in people with dense breast tissue, this examination can be supported by additional ultrasonography, 3-dimensional mammography (tomosynthesis) and breast MRI.
Why Is Mammography Indispensable?
Apart from the situations described above, one of the ways to recognize breast cancer in mammography is the detection of calcium deposits (calcification-calcification) at the cellular level.
These calcium deposits are very important for early diagnosis as they often show microscopic foci before a mass that can be detected manually or detected by ultrasonography. For the same reason, this situation makes mammography indispensable in screening, because these areas are either not visible at all or easily overlooked in ultrasonographic examination.
Is there any harm in mammography?
Since mammography is an imaging method that uses X-rays, it theoretically has some harmful effect on tissues. Compared to other imaging methods using X-rays, the radiation dose values received by the tissue during mammography are as follows:
sayfasında tablolar eksik:
|Screening Type||* Approx.dose of radiation exposure||Radiation equivalent of natural environment||** Additional lifelong risk of fatal cancer|
|Tooth x-ray||0.005 mSv||1 day||Can be neglected|
|Bone Densitometry(DEXA)||0.001 mSv||3 hours||Can be neglected|
|Mammography||0.4 mSv||7 weeks||Very low|
|Lung X-ray||0.1 mSv||10 days||Minimum|
|Spine X-ray||1.5 mSv||6 months||Very low|
|Kidney film (IVP)||3 mSv||1 year||Low|
|Brain Tomography(Cranial CT)||2-4 mSv||8-16 months||Low|
|Heart Tomography(Coronary CT)||12 mSv||4 years||Low|
|Lung Tomography(Thorax CT)||7 mSv||2 years||Low|
|İAbdominopelvic CT||20 mSv||7 years||Medium|
|These values are for a person of normal height-weight and may vary according to the structure of the person and the facility where the examination is made.
As can be seen from the table, the radiation obtained as a result of mammography is defined as one in 10-50 of computed tomography examinations, similar to direct radiography-x-ray examinations. In addition, the radiation received during a mammogram is equivalent to the natural ground radiation from the earth during 2-3 months of life on earth. According to the data of the last 30-40 years in which mammography has started to be used widely in the world, although there is no breast cancer case proved to develop due to the harmful effect of radiation given during mammography, and although this issue is still discussed in the scientific arena, a theoretical risk can be mentioned.
Apart from the harm of radiation, which is the most feared element among the people, mammography has some other undesirable effects. Among these, there are findings detected in mammography that require biopsy due to their suspicious features although they are not actually cancer, they require follow-up for benign lesions, and mammography cannot detect all cancers, as mentioned above.
As a result; Considering the loss / benefit ratio, mammography screening is considered indispensable with current scientific data. Likewise, when the data of 30-40 years of studies are evaluated, it is known that breast cancer deaths are reduced by approximately 30% by making early diagnosis thanks to mammography.
Should Mammography Be Digital?
Until the early 2000s, mammography was taken with non-digital (analog-conventional) methods, again using X-rays. The images were recorded on the receivers we call cassettes, and they were developed with a wet bath system and a film was obtained. No corrections or changes could be made to the image. The widespread use of digital systems in the early 2000s led to a move towards digital in mammography devices.
The digital system allows images to be reflected on monitors by being digitally processed after they are recorded in the cassette system using x-ray and with a different technology, and stored in digital media or as film if desired. Desired changes can be made on the images. In a study conducted in the USA in 2005, a digital mammography was shown to provide higher accuracy values and diagnostic superiority, especially in women under 50 years of age, who are or are going through menopause and with dense breast structure. Apart from this, it is known that digital mammography gives -20 less radiation to the breast tissue and obtains a better image with less breast compression compared to older analog mammographies.
When should mammography be done during your period?
Especially in women who are menstruating, it is not necessary to make an adjustment according to a certain period of the menstrual period for mammography. However, in some women, breast pain and tenderness starting a few days before menstruation and continuing in the first days of menstruation may increase the short-term pain felt during mammography. In this case, if the examination is not performed due to an urgent finding, the woman may be advised to have the mammography scan when the menstrual period is over or take a light painkiller pill a few hours before the examination.
Since it is taken before or during the menstrual period, there is no evidence supporting that breast cancer will not be seen (skipped) on mammography.
Is there any drawback in taking mammography at short intervals?
The most common reason for performing mammography at short intervals in our country is the fact that the same patients apply to different centers for diagnosis, the documents / films of the examinations are not properly kept by the patient and the doctor is not informed about this issue, and the quality of the film taken in some centers (due to factors related to the device and film bath) is not sufficient. is to be repeated. To prevent this, first of all, medical records should be filed by patients and shown to the doctor at each visit. Repeating the examination and performing an additional mammography examination due to the poor quality of the film does not cause real harm to the patient; On the contrary, delay in the diagnosis of cancer, which has been overlooked in an incomplete and inappropriate examination, may cause undesirable consequences for the patient. Apart from this, it should not be forgotten that this recommendation is always made considering the benefit-harm ratio of the patient, especially in the recommendations such as additional films and follow-up films after 6 months, which may be recommended by the radiologist.
Can Mammography Detect All Breast Cancers?
As mentioned above, mammography is insufficient to detect cancer, especially in cases where the breast tissue is more dense. This is the main reason why breast cancer cannot be detected (missed) on mammography. For this reason, in people with dense breast tissue, this examination can be supplemented with an additional ultrasonography examination or 3-dimensional mammography (tomosynthesis) method, which has been used in the last few years.
Can Breast Ultrasonography Be Used in Breast Cancer Screening?
Although breast ultrasonography is a harmless method that uses only sound waves, it is not recommended to be used alone in breast cancer screening. As mentioned above, mammography cannot detect all cancers in women with dense breast tissue, and in these cases the success rate drops to approximately 60%. In this case, in people with dense breast tissue, this examination should be supported by an additional ultrasonography examination. The main reason why ultrasonographic examinations are not used for breast cancer screening is that calcium deposits at the cellular level, which are an early symptom of breast cancer, cannot be seen by ultrasonography. In addition, ultrasonography detects many non-cancerous tissue formation that will require biopsy, causing unnecessary follow-ups and biopsies, and requiring more effort and time for the doctor to prevent it from being used for screening.