Mammography after Breast Conserving Treatment (BCT)
Removal of the entire breast, known as mastectomy, is one way of treating breast cancers. Most breast cancers can be just as effectively treated by breast conserving treatment (BCT) without removing the entire breast. Lumpectomy is a type of BCT and refers to removal of a cancerous lump and a narrow safety zone or margin of benign breast tissue. Lumpectomy is almost always combined with radiation treatment. Chemotherapy is often given. All of these are components of BCT.
A woman who has had BCT will need to continue having mammograms of the affected breast and of the unaffected side. Most radiologists recommend that patients have a mammogram of the treated breast six months after the completion of radiation treatment. Radiation and chemotherapy both cause changes in the skin and breast tissues that show up on the mammogram and make the examination more difficult to interpret. These changes are expected to be at a maximum at six months after the radiation is completed; the mammogram at this time establishes a new baseline for the affected breast for that woman.
Future mammograms will be compared to this exam to follow healing and check for recurrence. The next examination is then six months later when the woman is due for her yearly mammogram of both breasts. Experts differ on the best follow-up plan from this point on. Some prefer mammography of the treated breast every six months for 2-3 years; others suggest that annual mammograms are adequate. Each woman should consult her doctor for the plan that is best for her.
Mammography after breast reconstruction
Women who have undergone total, modified radical, or radical mastectomy for breast cancer need no further routine mammography of the affected side (or sides, if both breasts are removed). Mammography is continued for the unaffected breast at standard one-year intervals. This is very important, since women who have had one breast cancer are at higher risk of developing a new cancer of the other breast. One type of mastectomy that does require follow-up mammography is the subcutaneous mastectomy. In this operation, the woman retains her natural nipples and the tissue just under the skin; enough tissue is left behind to require yearly screening mammography in these patients. Any woman who is unclear of the type of mastectomy she has had should ask her physician.
Mammography is not routinely required for a breast removed by total, modified radical, or radical mastectomy and reconstructed with silicone gel or saline implants. If the patient has had subcutaneous mastectomy (discussed above), annual imaging is still needed.
After mastectomy, some women choose to have reconstruction with tissue from their own body, most often the abdomen (stomach) area. This type of reconstruction is called a TRAM flap reconstruction, which stands for Transverse Rectus Abdominus Myocutaneous flap. A patient who has had complete (not subcutaneous) mastectomy followed by TRAM flap reconstruction needs no further screening mammography on the affected side. If there is an area of the TRAM flap that is of concern on the physical examination, diagnostic mammography may occasionally be obtained. Further imaging with ultrasound or MRI may also be helpful.
Mammography after breast augmentation (enlargement) with implants
Women who have implants are a special challenge at mammography. The X-rays used for imaging the breasts cannot penetrate silicone or saline implants well enough to image the overlying or underlying breast tissue. Therefore, some breast tissue will not be seen on the mammogram, as it will be covered up by the implant.
In order to visualize as much breast tissue as possible, women with implants undergo four additional films, as well as the four standard images taken during screening mammography. In these additional X-ray pictures, called implant displacement (ID) views, the implant is pushed back against the chest wall and the breast is pulled forward over it. This allows better imaging of the forward most part of each breast. The implant displacement views are not as successful in women who have contractures (formation of hard scar tissue around the implants). They are easiest to obtain in women whose implants are placed underneath (behind) the chest muscle.
Although implant rupture can sometimes be diagnosed on the mammogram, often the ruptured implant will appear normal at mammography. Mammography does not cause implant rupture. Magnetic resonance imaging (MRI) is extremely accurate in detecting implant rupture. MRI is the imaging method of choice to evaluate the implant itself while mammography is still the best test for evaluating breast tissue.
The guidelines for screening mammography of women with implants are the same as for women without them. The number of pictures taken for each examination, however, is greater.