Radiation Therapy Cancer is the second leading cause of death in society surpassed only by death from heart disease. In the US in 1999, it is estimated that there would be 563,100 deaths due to cancer, more than 1,500 a day. The death rate from cancer increases with age. In the next 20-25 years persons born during the baby boom of the 40's and 50's in the United States will reach their 65th birthdays. As the majority of the population ages, the incidence of cancer rises. Once the diagnosis of cancer has been made, your doctor must determine the best course of therapy. Therapy of cancer may include:
What is Radiation Therapy
Using radiation to treat cancer dates back 100 years when the German, Dr. Roentgen first discovered X-rays. Radiation was first used on patients with superficial skin cancer. Initially, deeper lesions could not be treated since there was no effective way to control the power of the X-ray beam. Over the past few decades much progress has been made in this field. Now Radiation Therapy is one of the most effective means by which local/regional control of cancer is obtained. Radiation therapy is most often used to treat localized solid tumors, such as cancers of the skin, tongue, larynx, thyroid, brain, breast, prostate, bone, or uterine cervix. It can also be used to treat leukemia and lymphoma (cancers of the lymphatic system). More than one-half of the cancer patients in the United States will see a radiation oncologist at one point during their cancer treatment. As the population ages and the incidence of cancer rises proportionally the use of radiation therapy will be more heavily relied upon. What is a Radiation Oncologist Doctors who have special training in this field are called Radiation Oncologists. They have extensive training in the safe and proper use of radiation to treat disease. During the initial consultation, the radiation oncologist develops an individual treatment plan based on the patient's medical history, physical examination, review of laboratory tests, X-ray studies, and biopsies. The radiation oncologist monitors the patient's progress during the course of therapy and adjusts treatment to maximize killing of the cancer cells with the least possible side effects. This doctor usually works as part of a treatment team which may include the patient's personal physician, a surgeon, a medical oncologist, and nutritionist. The radiation oncologist is usually assisted by a medical radiation physicist and dosimetrist who are responsible for calculating and delivering the exact dose of radiation to the cancer tissue. Also present are radiation therapy technologists who work with equipment and assist the patients during treatment. Treatment Planning After the intial consultation, the radiation oncologist may do some special tests to pinpoint the treatment area. The radiation oncologist will work with the radiation physicist and dosimetrist to outline the target area and normal tissues in a computer to determine the best way to deliver the radiation theapy. During a process called simulation, the radiation therapist uses a special x-ray machine to determine the best area for treatment. This is called a treatment field or port. While the patient lies quietly and still on an X-ray table, the exact place on the body where the treatment will be aimed is marked. This process may take an hour or so and is not painful. To keep track of the ports, small semi-permanent or permanent marks may be applied to the skin. Treatment Schedules If the required dose of radiation was given in a single treatment, the dose would be high and would cause too many side effects. To avoid this, the total prescribed dose is administered over a course of smaller divided doses, called fractions. The number and length of each fraction is determined by the radiation oncologist.Treatments are usually given on a daily basis, five days per week for an average of 25 to 30 treatments. Weekend breaks allow normal cells time to recover. During each treatment, patient is positioned on a special table under a large machine and the radiation therapist uses the skin marks to identify the treatment port. In some special cases special shields may be placed to protect normal tissues or organs. Each external radiation therapy session takes about 15 to 30 minutes, but the actual radiation exposure is only about 1 to 5 minutes of that time. During that brief time the patient must remain as motionless as possible. You can't see or hear the radiation and receiving a radiation treatment is painless, just like having a picture taken. After each visit, the patient may resume normal daily activities and diet as tolerated. Combined Therapy Radiation therapy is often combined with surgery and chemotherapy to increase tumor destruction. Radiation therapy is frequently used after surgery to decrease the risk of local recurrences after surgery to the breast, lung, high-risk rectal cancers, and brain tumors. Preoperative radiation is sometimes used to shrink the size of a cancer to allow a less radical or disfiguring surgical procedure. In cases like these, the radiation oncologist must coordinate treatment plans with the cancer surgeon and medical oncologist. How Effective is Radiation Therapy The success rate of radiation therapy depends upon many factors such as the type of cancer being treated, how far it has spread throughout the body, and the patient's general medical condition. Obviously, a localized cancer of the type that is usually responsive to radiation has a better chance of shrinking than a widespread cancer that is resistent to radiation. When cancer has spread and can't be cured, radiation therapy may be used to decrease symptoms and make patients more comfortable. This is called palliative radiation. Symptoms such as pain, bleeding, compression of vital structures such as the brain, ulcerating skin lesions, and bone pain can often be improved with palliative radiation. Side Effects of Treatment Chemotherapy and Radiation Therapy both have the challenge of killing cancer cells without killing healthy normal tissue. This is possible due to the fact that cancer cells divide more rapidly than normal cells and these treatments tend to selectively kill rapidly dividing cells. However, all treatments kill some healthy tissue and side effects may occur. To limit side effects, radiation therapy is usually given as short burst of treatment over the course of multiple visits. Since radiation is generally used as a form of local treatment side effects are usually limited to the area being treated. To mininize skin burns, the port, or area where the radiation is given, may be used alternated with another. Often, people who receive radiation therapy experience some fatigue and decreased blood counts. Severe systemic side effects such as those seen with chemotherapy are less common. Side effects vary greatly from person to person depending on the area of treatment and the individual's tolerance. Specific side effects of treatment depends on certain factors: the total dose of radiation, the contour of the skin, the source of radiation and the size of the treatment field. These effects range from a simple minor redness/dryness of the skin (simple sunburn) to more advanced reactions where the skin becomes markedly reddened and there is peeling of the skin which becomes moist and drains. Hair loss will occur only within the treatment field. These reactions will heal in time and with treatment.
Treatment to the head and neck may include, but are not limited to, soreness of the mouth/throat, difficulty swallowing, dry mouth/altered taste which may cause loss of appetite, hoarseness and facial hair loss. There is also an increase risk of dental caries due to mouth dryness therefore care of this area and regular visits to the dentist are important to avoid complications. Treatment to the breast may include, but are not limited to, the above mentioned skin reaction and eventual mild retraction and tanning of the skin. There is also a very rare incidence of pneumonitis (inflammation of a small area of the lung under the chest wall of the treated breast) causing a dry cough and shortness of breath. This is generally treated with a short course of steroids and lasts only a short time. Treatment to the chest may include, but are not limited to, difficulty swallowing, mild nausea and dry cough. Pneumonitis may also cause a dry cough requiring treatment with a short course of steroids. Treatment to the abdomen may include, but are not limited to, nausea and abdominal cramping with or without diarrhea/frequent bowel movements. Treatment to the pelvis may include, but are not limited to, diarrhea causing rectal irritation, urinary frequency and hesitancy upon urination and impaired ability to have or maintain an erection. Long term or chronic effects of radiation also vary depending upon the area treated and the dose given to that area. These effects may include skin fibrosis (scarring), fibrosis of underlying organs, ulcer formation and rarely fistula (communication between two structures). These chronic effects may require surgery for repair. The incidence of these long term effects have significantly decreased with the many great strides made in this modality. Some of these advances include three dimensional conformal noncoplanar treatment planning, intensity modulation radiotherapy, high and low dose radioactive implants and stereotatic radiosurgery. We will be addressing these issues, as well as specific cancer sites and treatment recommendations in future updates. Self Help During Treatment It is the patient's reponsibility to keep their appointments as scheduled, cooperate with the treatment team, and report any side effects that may occur. Being treated for cancer is an overwhelming experience and many patients feel a loss of control and depression. This can be helped by realizing that what you do does make a difference. All cancer patients receiving radiation therapy need to take special care of themselves to protect their health and help the treatment succeed. Getting plenty of rest is important. Radiation therapy and other cancer treatments may cause fatigue. Patients should nap or sleep when their body tells them to rest. This is not the time for overworked hectic schedules. Good nutrition is also very important. A balanced high calorie diet may help prevent weight loss. Some patients are benefited by a nutritional consultation. The skin over the treatment area should be protected. Avoid adhesive tape over the treated area. Do not rub or scrub treated skin. Be gentle. Avoid very hot or very cold exposure and excessive sun exposure.Tight-fitting starched clothing should be avoided. Loose, soft cotton clothing is best. The doctor may prescribe a soothing lotion. Followup Examinations After the course of treatments is completed, patients are referred back to their medical doctors. However, most patients are asked to return periodically to see the radiation oncologist who can determine how well the radiation treatment worked. Follow-up times will range from once every week to once year, but they are very important. SOME COMMON MISCONCEPTIONS ABOUT RADIATION THERAPY:
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