Radiation Therapy Treatments
Radiation therapy (also called therapeutic radiology or radiation oncology) uses special kinds of energy waves or particles to fight cancer and sometimes non-cancerous diseases. Like surgery, radiation therapy is used in several ways depending on the type and location of the cancer. Certain levels of radiation work to destroy cancer cells or prevent normal or cancer cells from growing or reproducing. This treatment may provide a cure for cancer or non-cancerous diseases, control of disease, or relief of its symptoms. Radiotherapy uses high energy x-rays to destroy cancer cells. The radiation is targeted at the area affected by cancer so that it does as little harm as possible to normal cells.
Radiation therapy usually begins with these procedures:
- Initial Consultation
Once your physician considers the possibility of radiation therapy for your treatment, he/she will refer you to a radiation oncologist. The radiation oncologist is an oncologist who has special training and skills in using radiation to treat cancer and other diseases. You will have an initial office visit when the radiation oncologist reviews your history, completes a physical examination, views your x-ray studies and scans, and decides on the role of radiation therapy for treating your disease.
- Simulation Process
Following this initial visit, you will undergo a “simulation” process. The simulation allows the radiation oncologist to define the exact location and configuration of the cancer, tumor, or other growth within your body. In order to accomplish this, x-rays or scans will be taken in the radiation oncology department. Sometimes contrast is used to improve the quality of the information, for example you may be asked to swallow a contrast agent or you may be injected with one, similar to when you have a diagnostic CT scan performed. You will be placed in the treatment position, and often there will be customized “immobilization” devices such as mesh masks, headrests, or form-fit body molds to maintain your body position the same on a day to day basis. Sometimes, the area on your body that requires treatment will be marked with a tiny dot tattoo to make sure radiation is directed properly each day.
- Treatment Plan
Once the simulation process is completed, the radiation oncologist will determine your treatment plan, including the type of machine to use, the amount of radiation that is needed, and the number of treatments that will be given. Developing the treatment plan may be a complex process aided by the use of computers that recreate your “virtual anatomy” and location of your cancer or tumor. It may take several days to complete the treatment planning process.
What are the different types of radiation therapy?
Radiation therapy is given through different methods, depending on the type of disease, its location, and your general health. Often, radiation therapy is used in combination with other treatments. The following are some of the different types of radiation therapy with brief explanations of their goals:
- External radiation (external beam therapy)
With external radiation (external beam therapy), radiation is administered by a medical linear accelerator that points the radiation directly at the tumor. You will lie on an x-ray table with the same immobilization devices in place that were used in the simulation process. A specially-trained radiation therapist controls the machine. Special shields may be made to protect the tissue surrounding the treatment area, or sometimes protective devices are incorporated into the “head” of the treatment machine.
External beam radiation therapy is delivered in multiple “fractions”. Usually, treatments are delivered on a daily basis, five days per week. The duration will depend on the type of cancer and its location. At the outset, confirmatory x-rays are taken in the treatment position to confirm that the treatments have been designed properly. These are then reviewed by the radiation oncologist. Subsequently, each daily treatment requires only several minutes and you will not likely be in the treatment room any longer than 15 minutes.
Radiation treatments are painless, you feel absolutely nothing during a treatment. Although you are alone in the treatment room while the machine is turned on, you will be monitored with audio and video by the radiation therapist.
The two major types of radiation beams are photons and electrons. Both are produced by the linear accelerator. In general, photons (x-rays) travel completely through a body or tissue. Electrons penetrate to only a defined depth. Photons or electrons are chosen depending upon the location of a tumor. They may be used, in combination.
- Three-dimensional conformal radiation therapy
The use of CT scanning in the treatment simulation process permits the development of a three-dimensional treatment plan that allows the design of a complex combination of radiation beams focusing on a cancer. This is particularly useful in treating cancers that are adjacent to vital structures or near organs that are sensitive to the effects of radiation. Completion of a three-dimensional treatment plan requires CT scanning equipment, essential computer hardware and software, as well as skilled radiation oncologists and radiation dosimetrists.
- Intensity modulated radiotherapy (IMRT)
IMRT is one step further in the development of 3-D conformal radiation therapy. This is an advanced technique of dose calculation and treatment delivery that permits the advanced design of treatment fields to maximize the differential in dose delivered to tumors and normal tissues. It is especially useful in the management of prostate and head and neck cancers.
- Stereotactic radiation therapy or radio surgery
Stereotactic radiation therapy or radio surgery is a specialized form of external beam therapy. For this technique, multiple highly focused radiation beams are delivered from multiple directions with pinpoint accuracy. This form of treatment is often used for tumors or other growths within the skull, including arterio-venous malformations and acoustic neuromas. It may also be used for cancer or non-cancerous growths along the spine or even in other parts of the body. Radio surgery generally implies a single high dose or just a few high dose treatments. These treatments may be administered with a conventional medical linear accelerator or with a specially designed linear accelerator called the “CyberKnife.”
- Internal radiation (brachy therapy, implant radiation)
With internal radiation (brachy therapy, implant radiation), a high dose of radiation is given inside the body as close to a cancer as possible. The radiation device may be implanted directly into a tumour or placed into a body cavity. These techniques are commonly used for treatment of prostate, liver or gynaecological (cervix, uterus or vagina) cancers. For thyroid malignancies, radioactive iodine is injected intravenously. Some internal radiation treatments stay in the body temporarily and may require brief hospitalization other internal treatments stay in the body permanently (such as prostate “seed” implants), although the radioactive seeds lose their radiation within a short period of time. In some cases, both internal and external radiation therapies are used.
What are the most common risks and potential side effects of radiation therapy?
Radiation therapy is a painless cancer treatment, though it can cause irritation and inflammation in the tissues and organs in the path of the radiation beam. Radiation therapy may damage normal cells, in addition to the cancerous cells. This damage to the normal cells may cause side effects, which will be monitored and treated by your radiation oncologist.
As each person’s individual medical profile and diagnosis is different, so is his/her reaction to treatment. Side effects may be severe, mild, or absent. Be sure to discuss with your radiation oncologist any/all possible side effects of treatment before the treatment begins. These will be reviewed with you individually, and you will be asked to acknowledge these and sign a consent form before treatment is initiated. Some of the side effects of radiation therapy:
- Skin Irritation
Sometimes, radiation irritates the skin, especially if a cancer is close to the skin surface, causing it to become red, sore, and/or dry. For some people, skin irritation can become a troubling side effect. If you experience irritated skin during radiation treatment, consult your radiation oncologist or one of the radiation oncology nurses regarding how to treat the problem. Also, consider the following ways to protect your skin during treatment:
- Avoid sun exposure during treatment.
- Avoid exposure to extreme cold or hot temperatures, such as from an ice bag or a heating pad.
- Be gentle with the skin at all times, and use mild soaps, lotions, and other products with caution. Ask your radiation oncologist or radiation oncologist nurse for a list of recommended products and those to avoid.
- Use lukewarm water to wash the affected areas of your skin. Do not scrub the skin. Always pat the skin dry.
- Wear loose fitting clothing over the affected areas of skin.
Fatigue is a common side effect for all cancer patients. After weeks of radiation therapy, most people experience fatigue. Fatigue often resolves after treatment is completed.
Scientists have not determined the exact cause of fatigue. It may result from many factors, such as stress, pain, or a loss of sleep. Experts suggest that cancer patients with fatigue save their energy by limiting their activities. Ask friends and family to help you with certain tasks. Try to rest as much as possible. Also, including some light exercises, such as walking, into your daily routine may help you build energy.
- Hair loss (alopecia)
Hair loss may occur, but should be limited to the area being treated with radiation. For example, if you have radiation to your head you may lose hair on your scalp. However, if you are receiving radiation to your lung, you will not lose hair on your head. Hair usually grows back after treatment is finished.
If you experience hair loss on your scalp following treatment for a head or neck cancer, you may consider wearing a wig. Other people choose to wear a hat or scarf. Or you may decide that none of these options are right for you. If you choose to wear something on your head, make sure it is comfortable and does not irritate your skin.
- Blood changes
White blood cells and platelets can be affected by radiation therapy if the radiation fields include large areas of bone marrow or if you have been treated previously with chemotherapy. Your radiation oncologist will monitor blood counts during treatment to detect any problems, and he or she may choose to adjust your treatment if your blood cell counts decrease. Since blood cells fight infections and prevent bleeding, treatment may even stop for a while until the blood counts increase.
- Oral health
Radiation treatment to the head and neck area can cause dry mouth, difficulty in swallowing, cavities, gum destruction, sores in the mouth, redness and irritation, altered taste and smell sensations, and other side effects. It is important to take good care of your mouth, teeth, and throat during radiation therapy. Seeing a dentist before you start your radiation treatments can help prevent problems.
If you experience oral health problems during radiation treatment to the head or neck, talk to your radiation oncologist, radiation oncology nurse, or dentist about what you can do. Consider the following approaches to reduce your risk of side effects:
- Keeping your mouth moist. Drink water and use saliva substitutes if you have dry mouth.
- Clean your mouth regularly. Brush and floss your teeth after every meal and when you go to sleep. Make sure your toothpaste contains fluoride.
- Be careful about what you eat, as your diet affects the severity of side effects. Eat soft foods as much as you can and avoid spicy, crunchy, or sugary foods.
- Avoid mouthwashes that contain alcohol. Alcohol can cause the tissues of the mouth to become dry.
- Diarrhea, Nausea, and Vomiting
Radiation therapy to the abdomen may cause these side effects. Some patients experience nausea or an upset stomach a few hours after radiation treatment to the abdomen. Some patients find it helpful to eat a light meal a few hours prior to their treatment, while others prefer not to eat before their radiation treatment. You will need to work out a dietary plan that works best for you. Nausea may be most common during the first few days of treatment and taper down subsequently. Vomiting is uncommon and may be controlled with medications prescribed by your radiation oncologist. Diarrhea may also occur after a few weeks of radiation therapy to the abdomen or pelvis. Nausea, vomiting, and diarrhea are usually temporary side effects. You will likely not experience these side effects once your radiation treatments to the abdomen have been completed.
It is very important to maintain proper nutrition before, during, and after your radiation treatments.The main goal is to prevent weight loss.If you have nausea and vomiting, choose foods that are easy to chew, swallow, and digest, such as the following:
- Toast, crackers, and pretzels
- Cream of wheat, rice, oatmeal
- Boiled potatoes, rice, and noodles
- Skinned chicken that is baked or broiled, not fried
- Canned peaches or other soft, bland fruits and vegetables
- Clear liquids, clear carbonated beverages, apple/cranberry/grape juice, plain gelatin, Popsicles®, tea, and water
- Ice chips
- Carbonated drinks
With nausea and vomiting, try to avoid the following types of foods:
- Fatty, greasy, or fried foods
- Very sweet foods, such as candy or cookies, or cake with icing
- Spicy hot foods
- Foods with a strong odor
With nausea and vomiting, consider the following:
- Eat small amounts, often and slowly.
- Eat more of the foods that appeal to you.
- Eat in a place that is comfortable, avoiding stuffy places that are too warm or have cooking odors.
- Drink liquids a half hour before or after meals but not with your meals.
- Drink slowly or sip liquids throughout the day. Use a straw if necessary.
- Eat your food at room temperature or cooler, rather than hot.
- Do not force yourself to eat foods you normally like to eat because it may cause you to dislike them later when you feel better.
- Rest after you eats.
- For morning nausea, try eating crackers or toast before you get up.
- Wear loose fitting clothes.
- If you feel nauseated during treatment wait a couple of hours before eating.
- Keep a diary of when you feel nausea, how long it lasted, what you ate, and where you were. Your physician or nurse may need the information to help you better manage this side effect.
If you have diarrhea, consider foods such as the following:
- Yogurt and cottage cheese
- Rice, noodles, and potatoes
- Eggs (cooked until the whites are solid, not fried)
- Smooth peanut butter
- White bread
- Canned, peeled fruits, and well-cooked vegetables
- Skinned chicken or turkey, lean beef, and fish (broiled or baked, not fried)
With diarrhea, try to avoid the following types of foods:
- Fatty and fried foods
- Raw vegetables
- Fruit seeds, skins, and stringy fibers
- Vegetables high in fiber such as broccoli, corn, dried beans, cabbage, peas, and cauliflower
Some people need to avoid milk and dairy products when they have diarrhea. This is because they may not tolerate the lactose contained in these products.
- Difficulty in eating
Eating may be difficult during treatment. Radiation treatment can interfere with your body’s ability to absorb and digest food. It is also normal to lose weight during radiation therapy, but eating a balanced diet is important.
Talk to your radiation oncologist or a dietitian regarding what you should eat if you experience problems such as a loss of appetite. Patients who eat well usually cope better with treatment, both mentally and physically.
The following suggestions from the National Cancer Institute (NCI) can help if you have difficulty eating or loss of appetite even when you are feeling well with cancer:
- Eat small, frequent meals (every 1 to 2 hours).
- Eat high protein and high calorie foods (including snacks).
- Avoid foods low in calories and protein and avoid empty calories (such as soda).
- To avoid nausea and improve your appetite, do not drink liquids with your meals.
- Try to eat when you are feeling the best, no matter what time of day.
- Use meal substitutes, such as high-calorie, high-protein drinks, when you do not feel like eating.
- Try to increase your appetite through light exercise or appetite stimulants including a glass of wine or beer, if advised.
- Add extra calories and protein to food such as butter, skim milk powder, honey, or brown sugar.
- Take your medications with high-calorie fluids.
- Eat foods at room temperature.
- Avoid spicy foods or foods with strong odors