What is radiation therapy?
Radiation therapy is the treatment of disease using penetrating beams of high-energy waves called radiation. The radiation used for cancer treatment comes from special machines or from radioactive substances. Radiation therapy machines aim specific amounts of the radiation at tumors or parts of the body where there islwas disease. Radiation is sometimes given, even after tumors are removed to "sterilize" the area of cancer cells. It is added insurance that all cancer cells will be killed.
What is IMRT (Intensity Modulated Radiation Therapy)?
IMRT involves varying (or modulating) the intensity of the radiation (in this case, X-rays), being used as therapy for cancer. It is a relatively new form of radiation therapy that uses computer-generated images to plan and then deliver more tightly focused radiation beams to cancerous tumors than is possible with conventional radiotherapy. With this capability, clinicians can deliver a precise radiation dose that conforms to the shape of the tumor, while significantly reducing the amount of radiation to surrounding healthy tissues. Consequently, the technique can increase the rate of tumor control while significantly reducing adverse side effects.
Why would I want to be treated with IMRT?
IMRT is the most precise form of external radiation therapy available. It allows physicians to escalate the radiation dose to cancer cells, and in some cases, even more precisely to specific metabolically active regions within a tumor, while keeping the dose to surrounding tissues as low as possible. An analogy might be painting with a paintbrush as compared to using an airbrush and masking tape to protect outlying areas. The airbrush allows you to deposit variable amounts of paint in a
highly controlled fashion. IMRT does something similar with
radiation.
What kind of radiation is used in IMRT?
Currently, photons (X-rays) are used to deliver IMRT. The radiation is generated by a machine called a medical linear accelerator. This machine stands approximately nine feet tall, is nearly 15 feet long and can be rotated around the patient with great precision. Operationally, microwave energy, similar to that used in satellite television transmission, is used to accelerate electrons to nearly the speed of light. As they reach maximum speed they collide with a tungsten target, which in turn releases photons, or X-rays.
Does radiation therapy expose people to radioactive substances?
Many people, when they hear the word “radiation,” think immediately of radioactive substances. However, no radioactive substances are involved in the creation of X-rays or electrons by a medical linear accelerator. When a linear accelerator is switched “on,” radiation is produced and aimed directly at cancer cells. Then, like a flashlight, when the machine is switched off, there is no more radiation—none is “stored” or “transported.”
What happens when a person is treated with IMRT?
IMRT treatment involves three basic steps: diagnosis, treatment planning and delivery. As part of diagnosis, physicians generate three-dimensional diagnostic images (usually CT or MRI) of the patient’s anatomy and use these to specify the dose of radiation each area will receive. In most cases, treatment planning includes a simulation session to further localize the cancer and finalize the radiation treatment plan. Patients receive the IMRT treatment according to various schedules, usually five days a week for six or seven weeks. Each treatment takes ten to fifteen minutes.
What is the IMRT process like?
The IMRT process is similar to a typical radiation treatment, and it depends, to some extent, on a particular hospital’s approach to radiation oncology. Typically, after conducting a physical exam and a medical history review, the radiation oncologist determines an individualized course of treatment for each patient and runs the equipment that delivers the radiation.
How Long Is a Course of IMRT Treatment?
Radiation therapy usually is given five days a week for six or seven weeks. When radiation is used for palliative care, the course of treatment lasts for two to three weeks. For each radiation therapy session, the patient is in the treatment room for about 15 to 30 minutes. These types of schedules, which use small amounts of daily radiation rather than a few large doses, help protect normal body tissues in the treatment area. Weekend rest breaks allow normal cells to recover. The total dose of radiation and the number of treatments a patient needs depend on the size and location of the cancer, the type of tumor, the patient’s general health and other factors.
What Are the Effects of Treatment?
External radiation therapy does not cause a patient’s body to become radioactive. Patients need not avoid being with other people because of treatment. Even hugging, kissing, or having sexual relations with others pose no risk to them of radiation exposure.
Side effects of radiation therapy most often are related to the area that is being treated. Most side effects that occur during radiation therapy, although unpleasant, are not serious and can be controlled with medication or diet. They usually go away within a few weeks after treatment ends. With radiation treatment, some patients have no side effects at all.
Is Radiation Treatment Expensive?
Treatment of cancer with radiation can be costly. It requires very complex equipment and the services of many health care professionals. The exact cost of your radiation therapy will depend on the type and number of treatments you need.
Fortunately, Medicare and many health insurance policies cover the charges for radiation treatments. It’s a good idea to talk with your insurer and with your doctor’s office staff or the hospital business office about your policy and how expected costs will be paid.
Who is on the radiation health care team?
Radiation Oncologist- the specially trained physician who will prescribe the type and amount of treatment that is correct for you. The radiation oncologist will work closely with the other doctors and health care professionals that make up your health care team.
Radiation nurse- will help to learn about your cancer and the treatment. They can tell you how to manage side effects also. The nurse can help you to set up visits with other members of the health care team. Some radiation treatment centers may include a physician assistant, dietitian, physical therapist and/or social worker on the team of workers available to help you during your radiation.
Radiation physicist- is the person who makes sure that the equipment is working properly and that the machine delivers the right amount of radiation. The physicist will also work closely with the radiation oncologist to plan your treatment.
Dosimetrist- will work under the direction of the radiation oncologist and the physicist. They help to carry out your treatment plan by calculating the amount of radiation to be delivered to the cancer and the normal tissues that are close by.
Radiation therapist or radiation therapy technologist (RT)- is the person who will position you for the treatments and runs the machine that delivers the radiation.
How does radiation therapy work?
Cancer cells grow and divide more rapidly than many of the normal cells around them. High doses of radiation can kill cells or keep them from growing and dividing, and it has proven to be particularly effective in killing cancer cells and shrinking tumors. Although some normal cells are affected by radiation, most normal cells recover more fully from the effects of radiation than do cancer cells.
