Radiation therapy has a number of applications in the treatment of breast cancer. It prevents cell reproduction; since cancer cells grow and divide more rapidly than normal ones, it acts to check a malignant growth. In breast cancer, radiation therapy is used most often as an adjunct to surgical treatment, especially following a segmental mastectomy. It is rarely the sole treatment for breast cancer, although it may be used alone against inflammatory breast cancer, for breast cancer so advanced that mastectomy would not be effective (Stage IV), or for patients who are too ill to undergo mastectomy or who are absolutely opposed to it. Radiation therapy also may be administered to reduce the size of a large breast tumor to make it easier to remove or to alleviate the pain caused by metastases, especially in the skeletal system.
Contrary to some thinking in the past, radiation therapy is no longer considered necessary to destroy cancer cells after a mastectomy. Instead, it is used most often following a lumpectomy. In recent years a number of radiation therapy specialists have argued that radiation therapy following removal of the breast tumor alone is as effective as the more extensive mastectomy in achieving a cure for cancer. In this approach the surgery may be an excisional biopsy, lumpectomy, or segmental mastectomy, sometimes with removal of some of the lymph nodes for staging purposes. A few days after the tumor is removed, a series of radiation treatments—usually four or five a week over a four-to-six-week period—is administered on an outpatient basis.
A total of about 5,000 rads of radiation will be directed to the breast, chest wall, and remaining lymph nodes. These treatments may be followed by a second phase of radiation therapy, consisting of a concentrated booster dose of radiation to the area where the cancer occurred. The radiation may be administered in one of two ways. In one method, several tubes are implanted into the breast to hold the radioactive iridium seeds. This is usually done under local anesthesia, although some women may request that a general anesthesia be used instead. The implants will remain in place fifty to sixty hours and will deliver about 2,000 rads directly to the surrounding tissue. The woman remains in the hospital while the implants are in place, and will be confined to her room with limited visitors to protect others against the small amounts of radiation that are released by the implants. After they are removed, there is no further exposure to the radiation and the woman usually goes home the same day.
Alternatively, a series of external radiation treatments using a concentrated electron beam may be administered. The procedure is similar to the previous radiation treatments, requiring that the woman come to the radiation therapy department daily for five to ten treatments.
Improved machinery and techniques have reduced the number of adverse effects of radiation therapy. After a few weeks of radiation therapy, most women find that their skin in the treated areas looks and feels sunburned. This redness is gradually replaced by a tanned look. Eventually the skin may become thickened, and some women find it is more sensitive while others experience a decrease in sensitivity. The breast may become smaller and firmer because the radiation stimulates development of fibrous tissue; other women find the breast is larger because of a buildup of fluid.
Since the radiation does not penetrate to the deeper internal organs, there is generally no nausea or vomiting. If these do occur, antinausea drugs can be taken. There may be a slight cough due to minor exposure of the lung to the radiation. Many women also find that the treatments leave them feeling more tired than usual, although most are able to go about their normal routine.