Understanding Radiation Therapy
Radiation therapy, also called radiotherapy, uses carefully targeted doses of high-energy radiation to kill cancer cells. Doctors use radiation therapy to treat just about every type of cancer. It does this by altering the DNA within cancer cells—preventing the cancer cells from reproducing and growing. Radiation therapy is also useful in treating some noncancerous (benign) tumors.
The goal of radiation therapy is to control cancer locally, that is, to shrink a tumor so that it will not spread to other organs. Sometimes, radiation therapy may destroy a tumor, and no other therapy is needed. Radiation may sometimes be used before surgery to shrink a tumor, or to minimize the need for invasive surgery. Sometimes, radiation therapy may be used to treat the symptoms of cancer even when cancer has progressed beyond a cure.
The term "radiation therapy" most often refers to external beam radiation therapy. During this type of radiation, the high-energy beams come from a machine outside of your body that aims the beams at a precise point in your body.
While both healthy and cancerous cells are damaged by radiation therapy, the goal of radiation therapy is to destroy as few normal, healthy cells as possible.
Radiation therapy has been used to treat cancer successfully for more than 100 years, after a German physicist discovered the powerful X-ray. Over the decades, radiation therapy has become extremely sophisticated, with radiation oncologists and the team of specialists who work with them now able to target tumors more precisely than ever. Also, advances have allowed for greater levels of intensity to smaller areas, thus minimizing damage to nearby tissues.
Different kinds of cancer have varying sensitivity to radiation, and the type and dosage of radiation you receive will be tailored to your specific cancer. While most radiation is administered externally, some radiation therapy today is internally administered. In those cases, such things are radioactive “seeds” or balloons are surgically implanted or sometimes inserted into a body cavity that is affected by cancer.
With external radiation, also known as external beam radiation therapy (EBRT), patients generally receive radiation for about 20 to 30 minutes, five days a week, for about six weeks.
To precisely “aim” radiation at the specific cancer cells that need to be targeted, your WellStar doctors may use a computed topography (CT) scan and a computer that helps target the beam. This technology is called three dimensional conformal radiation technology (3D-CRT). Your WellStar team is expert in determining whether 3D-CRT may be beneficial to you.
Other, new radiation techniques have been developed that may allow patients to receive a more intense dosage for a shorter period of time. This can allow patients to complete their full radiation regimen in a shorter time. Ask your WellStar physician if you might be a candidate for these treatments.
WellStar is a leader in the use of an advanced radiation technique known as intensity modulated radiation therapy (IMRT), an advanced form of 3D-CRT. IMRT allows your WellStar physician to precisely control the intensity of the radiation that different parts of a tumor receive. This happens through the use of computer-controlled, movable “leaves” that either aim or block beams aimed at the treatment area. The leaves are carefully adjusted according to the size, shape and location of the tumor. WellStar is a leader in the use of IMRT, which helps protect nearby, healthy cells while maximizing the treatment to cancer cells.
The size of your tumor, the type of cancer cell that you have, and other factors influence the choice of radiation therapy. Talk to your WellStar physician about options. Radiation is sometimes administered internally into or near the cancer. This is called brachytherapy. Brachytherapy allows for a higher dose of radiation over a shorter period of time. In brachytherapy, radioactive material is inserted via small wires, balloons, needles or, as in the case of prostate cancer, even seeds the size of rice grains that may be left in the body permanently. (Their radioactive properties diminish over time).
Brachytherapy is sometimes used to boost the effectiveness of external radiation, and sometimes used on its own. It has been shown to be effective in treating prostate, cervical, uterine, vaginal, and head and neck cancers. Breast cancer has its own type of brachytherapy. For breast cancer patients who have breast-conserving surgery rather than mastectomy, radiation can be administered internally for five days, twice a day. In breast brachytherapy, a small balloon is administered into the cavity where the cancer was removed. A catheter leads from the balloon to the outside of the body. The balloon is filled with saline solution. When treatment is administered, a radioactive seed is inserted into the solution. The balloon and catheter are removed at the end of the five days, and no radioactive material remains in the woman’s body after the treatment.
In rare cases, such as for thyroid cancer, radiation can be administered intravenously. In thyroid cancer, radioactive iodine is administered and naturally absorbed by the thyroid gland.
Radiation is not without side effects and complications. While most people tolerate radiation therapy relatively well, fatigue is a common symptom. Side effects of radiation therapy greatly depend on which part of your body is being exposed to radiation and how much radiation is used. You may experience no side effects, or you may experience several. Most side effects are temporary, can be controlled and generally disappear over time once treatment has ended.
||COMMON SIDE EFFECTS|
||Hair loss at treatment site (sometimes permanent), skin irritation at treatment site, fatigue|
|Head and Neck
||Dry mouth, thickened saliva, difficulty swallowing, sore throat, changes in the way food tastes, earaches, sore jaw, nausea|
||Difficulty swallowing, cough, shortness of breath|
||Nausea, vomiting, diarrhea|
||Diarrhea, bladder irritation, frequent urination, sexual dysfunction|
Some side effects may develop later. For example, in rare circumstances a new cancer (second primary cancer) that's different from the first one treated with radiation may develop years later. Ask your doctor about potential side effects, both short and long term that may occur after your treatment. Talk to your WellStar physician about these issues; he or she is always ready to talk to you about any of your concerns.