What is mammography?
Mammography is a diagnostic imaging technique that consists of the radiological examination of the breast using low energy X-rays, obtaining a radiographic image of the breast, which is used for the diagnosis of breast diseases, and in a special way, for the early detection of breast cancer, i.e. for the diagnosis of breast cancer in its early stages.
What is the mammography process?
Mammograms are performed on an outpatient basis by appropriately qualified technical personnel (radiology technicians), and will subsequently be interpreted by a radiologist who is an expert in breast pathology.
The devices used to perform mammography are called mammographs, and they are specially designed for the exclusive performance of mammograms.
To perform the mammography, the technician will place the breast on a platform of plastic material, proceeding then to compress it in an appropriate manner by means of another plate of the same material. In this way, radiographic images of the breasts will be obtained from different angles (projections), usually a cranial-caudal (horizontal) projection and an oblique-lateral projection of each breast.
Although compression of the breast can sometimes cause some pain, it is necessary to perform it to reduce the thickness of the breast, thus improving the quality of the images obtained and at the same time reducing the dose of radiation deposited in the breast tissue.
The procedure to obtain a mammogram of the breasts lasts approximately 20 minutes.
Why is this test performed?
Mammography is used for the diagnosis of breast disease, but where it plays an important role is in screening programs (early diagnosis) of breast cancer in asymptomatic women.
Early detection of breast cancer is believed to decrease mortality rates in women who undergo these screening programs.
The American College of Radiology recommends starting annual mammographic screening at age 40.
The objective of early detection programs is to diagnose small lesions, generally smaller than 1 cm in diameter.
Breast cancer screening programs will detect 6-10 breast cancers per 1,000 women at the first examination, and 2-4 cancers per 1,000 women at subsequent examinations.
In addition to its use for the early detection of breast cancer, mammography plays a very important role in the follow-up of patients who have been previously diagnosed and treated for breast cancer.
What are the benefits for the patient?
The main benefit of performing mammography is the early detection of breast cancer in asymptomatic women, which translates into a considerable reduction in breast cancer mortality rates (29-45%).
In addition, early detection of cancer allows less aggressive local treatments to be carried out, which will make it possible to preserve the breast, avoiding its amputation, with the consequent improvement in the quality of life of the patients.
What are the risks of mammography?
The main risk of mammography is the use of ionizing radiation (X-rays) and the consequent absorption of radiation dose by the breast tissue, with the potential risk of inducing breast cancer. Therefore, this potential risk should not be ignored, but it is also true that the risk must be weighed against the benefit to be gained from mammography.
The estimated risk for the occurrence of breast cancer from the use of X-rays for diagnostic purposes is very low in relation to the rate of cancers detected in early detection programs, and the benefit obtained in mortality reduction with early detection programs has already been mentioned.
There is no scientific evidence that has demonstrated that the current dose ranges administered to breast tissue during mammography induce breast cancer.