Breast imaging is no longer synonymous with mammography alone. Although mammography remains the most important of the screening tools used to detect early breast cancer or to evaluate clinical abnormalities, breast sonography, MRI, ductography, technetium sestamibi (Miraluma) imaging, and PET scanning are also used. At Breastlink we also use image-guided biopsies and needle localizations. There are a few other studies such as thermography or diaphanography which are not universally accepted as useful. This discussion will be limited to the most commonly used imaging procedures, and will ignore ones which are unproven or being investigated.
The death rate from breast cancer has been dropping since 1989. Studies show that women who obtain annual mammograms age 50 and over reduce their risk of dying from breast cancer by 35%. Recent studies suggest annual mammograms may lower the chance of dying from breast cancer in women age 40 to 50 by 25-35%. When factors such as aged are taken into account, there is a 44 % reduced risk of being diagnosed with advanced breast cancer if you have regular mammograms in your forties. Mammography could, therefore, help women in this age group by picking up cancer at an earlier stage, when it is easier to treat successfully.
One of the most important reasons is the evolution of high-quality mammography and its increased acceptance by women. Standards were established by the American College of Radiology in 1986 for performing mammography (Mammography Accreditation Program) in an attempt to educate those working in mammography and to lower the radiation dose and improve quality. This raised standards nationwide. In 1994 the FDA began to issue certification of all facilities under the Mammography Quality Standards Act (MQSA). The standards apply to the equipment, the technologist, the radiologist, processors and films, and the physicist. The result has been very positive for the consumer.
A mammogram is an x-ray of the breasts. The x-ray is made by a special machine developed specifically for breast imaging. The breast is held firmly between two plastic paddles to prevent motion, and to flatten the breast and spread out the tissue to make it easier to see small cancers. This also reduces the radiation dose. The radiation absorbed by the breast is exponentially proportional to the thickness of the breast.
Some women are fearful of the radiation from mammography. The average dose is 0.1 to 0.2 rad dose per image. If a woman had a mammogram every year of her life from age 40 to 90, she would have received only 20-40 rads. (Compare this to the radiation given to the breast if a cancer is being treated of 4000 to 5000 rads.) There are no studies that have shown this dose is harmful. In fact, some studies have proposed that small doses of radiation may actually be beneficial to living organisms. This is controversial. One doctor uses the analogy that the amount of radiation received by a patient from mammography is the same as she would receive walking naked along a beach in the middle of the day in the bright sun for 10 minutes, or the time it would take for the authorities to arrest her. The risk of any adverse effect from the radiation is far outweighed by the benefit of discovering cancer of the breast early enough to treat it and potentially save your life. However, we are always mindful of the fact we are using radiation, and always strive to keep the dose to a minimum.
The breast imaging specialist (breast imager or mammographer) is a board-certified radiologist who has limited his or her practice to breast imaging and the interpretation of screening mammograms. S/he also does diagnostic work-ups for clinical abnormalities or abnormal mammograms using ultrasound, additional x-rays and a physical exam. The radiologist works closely with the surgeons and oncologists to detect and follow cancers. S/he is involved in detecting possible spread of the cancers. The radiologist performs biopsies and other interventional procedures on the breast, such as drainages or removal of small benign tumors. As a profession radiologists are very passionate about their work. Breast imaging is one of the few areas of radiology in which radiologists can really make a difference in the lives of patients.
Interpreting mammograms has been described as one of the most difficult tasks faced by radiologists. Obviously the best equipment, film and processors, as well as highly trained technologists and radiologists, are required. At Breastlink we use the best equipment and film, and all of our facilities are staffed by highly trained specialists. In the United States there is a shortage of imagers and not all Mammography Centers are staffed with experts in breast radiology.
There are two types of mammograms: a screening mammogram and a diagnostic mammogram.
The screening mammogram is for a patient who has no complaints and who has never had breast cancer. The American Cancer Society, the American College of Radiology, the American College of Obstetrics and Gynecology, and the National Cancer Institute recommend annual screening for women beginning at age 40. Screening should begin earlier if a woman has a mother or older sibling who had breast cancer earlier than age 40. We concur with these recommendations.
The radiologist looks for asymmetry, small speculations, certain small calcifications, masses, or spiculated or stellate-appearing breast tissue. In fatty breasts the job is easier. In dense, fibrous breasts or in a younger woman’s very glandular breasts, the job is very difficult. One doctor described the process of finding cancer in a dense breast as "trying to find a polar bear in a snow storm.” I think it is even more difficult than that. A polar bear usually looks the same when you see him. Breast cancers often look different each time you see them.
Tiny shadows on a mammogram may not mean anything on their owb, but if they are new they could be significant. It is therefore extremely important for you to make sure the radiologist has your previous x-rays for comparison when he or she reads your mammogram. There are many changes which are benign. Other subtle changes from one year to the next could indicate a cancer. This would be apparent only if a comparison with previous mammograms could be made. There are few things more helpful to the radiologist than having old films.
Screening mammograms are generally read in “batches” by an expert radiologist working in a quiet, dark room without distraction. Attempting to get an immediate interpretation is discouraged unless there is an overriding emergency. It is better for you if the films are read when the radiologist is not rushed and able to concentrate fully on looking for cancer on your films. You will get a written report in about five to seven days. If you have not received a report by ten days, contact the facility. Never assume “no news is good news”.
We believe it is important to make screening mammography available to all women. We do not require a referral or a prescription from another physician. You may call us directly for an appointment. You will be given the results. If the mammogram is suspicious for malignancy, we have experts in the field to make recommendations and/or treat you. We can also help you find a family physician if you need one.
The diagnostic mammogram is an x-ray of the breast or breasts for a specific problem or an abnormal screening mammogram. You would be contacted for a diagnostic mammogram if there were shadows on the screening mammogram, which needed further evaluation. A diagnostic mammogram will also be performed if either you or your doctor finds a mass. Other reasons for a diagnostic mammogram can be a complaint of pain, or discharge, or skin changes. Up to 10% of screening mammograms require additional studies. Of these, only 8 to 10 in 100 will require biopsy. Only 20% of those biopsied with calcifications will have cancer. The diagnostic mammogram is often performed in conjunction with another imaging study, the breast ultrasound. In fact, almost invariably, if you have a palpable mass, you will obtain an ultrasound as part of the “diagnostic work-up”. When the radiologist is 98% sure that a finding is benign, and s/he does not want to put a woman through an unnecessary biopsy, s/he will call it “probably benign” and ask her to return in three to six months for repeat ultrasound or mammogram to ensure stability. In the unlikely (less than 2%) event the finding is not benign, the short wait will not have changed your chances for cure.
The most commonly used mammogram technique is the film-screen technique. The images are produced on high-contrast, low-dose x-ray film, and read by the radiologist after they have been processed. Another type of mammogram is the digital mammogram. The FDA approved this technology only a few years ago. It produces an image in a computer. The images are then read off a high-resolution computer screen by the radiologist. The advantage is that the mammograms are much faster to obtain, require no films or file rooms, have lower radiation dose, and the radiologist can manipulate the images to interpret them. The call-back rate is decreased because many questions can be answered by manipulating the images. There are no suboptimal films, since each image can be manipulated to look at dark and light tissues. The disadvantages are that digital mammograms take longer to read (each becomes almost a diagnostic mammogram), the equipment is four to five times more expensive, and the facility will have to have a machine to make film copies of the digital mammograms when they need to send records to another facility that does not have digital. A large multi-institutional study is now trying to determine if digital mammography is superior to film-screen mammography.
The breast sonogram or ultrasound is performed either by a specially trained technologist or a radiologist, or both. The study is performed using a machine that sends high-frequency sound waves into the breast, and then creates an image on a screen from the echoes. Pictures are made from selected images and saved on film. The procedure is painless. However, it is time consuming and very “operator dependent”. Ultrasound is not an accepted screening procedure, and does not take the place of mammography. It cannot see many calcifications, and would miss many of the “in situ” cancers detected with mammography. It can, however, see masses or cysts in dense breast tissue that mammography cannot see. It can usually enable us to determine whether a mass seen on a mammogram is a solid tumor or a benign cyst. It enables us to determine if a palpable “mass” is simply benign, or fibrous breast tissue (lumpy breasts), or a real mass or cyst. It can often help us decide whether a solid mass is benign or malignant. It is an extremely useful tool to use along with the mammogram. Ultrasound is also used for guidance when a biopsy or needle localization is needed.
At Breastlink, we always tell you, the patient, at the time of the diagnostic work-up what we are finding, and what we will be reporting to your physician. We never make you wait until you can get an appointment with your physician to learn the results. Our radiologists are consultants, and we are consulting for your benefit; you deserve to know the findings as soon as possible, so that you know what you need to do. This also eliminates the possibility of your doctor not seeing or receiving the report of a serious problem and never contacting you.
If we find a suspicious mass or a suspicious cluster of microcalcifications during the diagnostic work-up, we will recommend a biopsy. Today, the percutaneous biopsy under ultrasound guidance or x-ray guide stereotactic technique is most often the procedure of choice. (Stereotactic guidance is usedalmost exclusively for calcifications and ultrasound guidance for masses). The other choice would be an open surgical biopsy. The advantages of an image-guided percutaneous procedure are that it is quicker, much less expensive, leaves no scar or defect, and is as accurate as an open biopsy. If a surgeon knows before he/she does a surgical procedure that he/she is dealing with a cancer, they will get a better result need to undertake fewer procedures. If the surgeon knows beforehand that the lesion is malignant, he/she is much more likely to get the entire tumor when performing a lumpectomy.
At Breastlink, we are almost always are able to give you the opportunity to have a percutaneous biopsy at the same time as you have your diagnostic work-up, if we feel it is needed. We do not make you wait for days or weeks. Contrary to some practices, we do not force you to leave, make an appointment with your personal physician, and then get a referral back to us for the recommended biopsy. This can delay the diagnosis for weeks. We are occasionally required to wait for approval from an insurance company, but this is rare.
The ultrasound-guided biopsy is the most commonly performed percutaneous biopsy. (Approximately 80% compared to 20%, which are stereotactic biopsies.) It is done for masses or areas of shadowing which can be seen with ultrasound. Calcifications are usually biopsied using stereotactic technique. Occasionally calcifications can be seen in tumor-filled ducts, and can be biopsied under ultrasound guidance. The lesion is located with ultrasound, and, under local anesthesia, a special needle is placed in the breast. The needle will take tissue from the area of interest for the pathologist to look at under the microscope. The procedure is essentially painless and quite safe. Recovery time is minimal. It usually takes 30 minutes or less.
We use the same technology to remove small benign tumors. Papillomas and small fibroadenomas can be removed without surgery using the same techniques as for a biopsy. A small needle is inserted into the breast under local anesthetic, and the small tumor is taken out in small sections using a rotating blade and suction. The procedure leaves no scar or defect in the breast. It is done on an outpatient basis.
The stereotactic biopsy uses an x-ray machine which takes two pictures 30 degrees from each other, then a computer triangulates the exact position in the breast where the calcifications (or mass) lies. The radiologist tunes in these coordinates, and the needle is placed into the breast in the same manner as described above, using local anesthesia. Often a tiny clip is placed in the breast to mark the site where the calcifications were sampled, in case they are removed and the pathology is reported as malignant. The surgeon will then know where to go in the breast to do the definitive “lumpectomy”.
The needles in a biopsy are specially designed for biopsies. They may be automated, spring loaded, or could have a vacuum assistance, or have radio waves to assist in passing into the breast. One new device uses freezing of tissue to aid in acquiring a sample.
These procedures are usually quite painless and have extremely few complications. They are done on an outpatient basis, and they usually take less than an hour.
We have a wonderful working relationship with our dedicated pathologists. They usually get the results of the biopsies back to us within 24 hours, decreasing the anxiety for the patient (and us). Only when the pathologists are doing additional stains or tests on the specimen, might the results take longer. This quick turnaround time is not the standard in most practices.
If you have a spontaneous nipple discharge that is unilateral, clear or bloody, a ductogram (or galactogram) may be performed. The doctor places a tiny blunt tipped tube into the offending nipple duct and injects a minute amount of contrast. Mammograms are taken to visualize the ducts, and to detect tumors or lining irregularities that might be responsible for the discharge. The procedure is usually painless. If you have a spontaneous discharge, the offending duct will usually be dilated, and the cannula will almost fall into it.
A needle localization procedure is done for a patient who is going to have a surgical biopsy, or a lumpectomy. Most often it is done when the surgeon cannot feel an abnormality. In order to ensure the removal of as little tissue as possible, the abnormality is marked with a fine, hooked wire. The surgeon then cuts down to the tip of the wire and can then usually remove all the abnormal tissue. The localization can be performed using either x-rays (calcifications) or ultrasound (small, non-palpable masses), using local anesthesia. It usually takes 5-10 minutes with ultrasound, and a little longer with mammography.
Other imaging studies include nuclear medicine exams. The radiation comes from within the patient. A radioactive material is injected into a vein, and the tumor cells concentrate the compound that is radioactive. A special camera sensitive to radiation creates an image based on the radiation from different parts of the breast and body. One such test is the sestamibi study. It is usually used when the doctor thinks there may be active cancer cells in the breast and they cannot be found by other means. It is more sensitive for larger tumors. The study only is about 30% sensitive in small tumors. When positive, it has up to a 28% chance of being wrong. It occasionally misses even very large tumors. It only complements mammography and is not a replacement for it.
The PET scan uses a radioactive substance bound to a type of glucose (sugar). This is injected into a patient, and is then taken up by rapidly dividing cells (e.g. cancer cells). A picture is made with a camera outside the body. The camera sees “hot spots” which are likely to represent cancers. A cat scan can be performed simultaneously, and the images superimposed to pinpoint the sites of the increased activity. This is most often used to detect spread of a cancer to other parts of the body and to detect lymph nodes that might have tumors.
Breast MRI is covered in a separate section on this website. This is rapidly becoming the most important test in the diagnostic work-up of a patient who might have breast cancer. It is not a screening procedure. One of the disadvantages is that it is time consuming and expensive.
One of the best pro-active health-care actions you can take is to have a screening mammogram as recommended above, or as recommended by your personal physician if there are problems. Make sure the person interpreting your mammogram is a “specialist in mammography”. Ensure that the interpreting physician has your previous mammograms. Finally, make sure you know the results. Be your own advocate, and actively seek to maintain good health.
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