PA radiation treatment is available for numerous forms of cancer. Radiation therapy (also called radiotherapy, X-ray therapy, or irradiation) is the use of a certain type of energy (called ionizing radiation) to kill cancer cells and shrink tumors. Radiation therapy injures or destroys cells in the area being treated (the target tissue) by damaging their genetic material, making it impossible for the cells to continue to grow and divide. Although radiation damages both cancer cells and normal cells, most normal cells can recover from the effects of radiation and function properly. The goal of radiation therapy is to damage as many cancer cells as possible, while limiting harm to nearby healthy tissue.
There are different types of radiation and different ways to deliver the radiation. For example, certain types of radiation can penetrate deeper into the body than others. In addition, some types of radiation can be very finely controlled to treat only a small area (an inch of tissue, for example) without damaging nearby tissues and organs. Other types of radiation are better for treating larger areas.?
In some cases, the goal of radiation treatment is the complete destruction of an entire tumor. In other cases, the aim is to shrink a tumor and relieve symptoms. In any case, whether it is for lymphoma cancer treatment or small cell lung cancer treatment, doctors plan treatment to spare as much healthy tissue as possible.
About half of all cancer patients receive some type of radiation therapy. Radiation therapy may be used alone or in combination with other cancer treatments, such as chemotherapy or surgery. In some cases, a patient may receive more than one type of radiation therapy.
- Radiation treatments are painless.?
- External radiation treatment does not make a person radioactive.
- Patients need to allow 30 minutes for each treatment session, although the treatment itself takes only a few minutes.
- It's important to get plenty of rest and to eat a well-balanced diet during the course of radiation therapy.
- Skin in the treated area may become sensitive and easily irritated.
- Side effects of radiation treatment are usually temporary, and vary depending on the area of the body being treated.
Types of Radiation
Radiation may come from a machine outside the body (external radiation), may be placed inside the body (internal radiation), or may use unsealed radioactive materials that go throughout the body (systemic radiation therapy). The type of radiation to be given depends on the type of cancer, its location, how far into the body the radiation will need to go, the patient's general health and medical history, whether the patient will have other types of cancer treatment, and other factors.
Most people who receive radiation therapy for cancer have external radiation. Some patients have both external and internal or systemic radiation therapy. These can be given either one after the other or at the same time.
External radiation therapy usually is given on an outpatient basis; most patients do not need to stay in the hospital. External radiation therapy is used to treat most types of cancer, including cancer of the bladder, brain, breast, cervix, larynx, lung, or prostate. In addition, external radiation may be used to relieve pain or ease other problems when cancer spreads to other parts of the body from the primary site.
Prophylactic cranial irradiation (PCI)is external radiation given to the brain when the primary cancer (for example, small cell lung cancer) has a high risk of spreading to the brain.
Intensity-modulated radiation therapy (IMRT). IMRT is a new type of 3-D conformal radiation therapy that uses radiation beams (usually X-rays) of varying intensities to deliver different doses of radiation to small areas of tissue at the same time. The technology allows for the delivery of higher doses of radiation within the tumor and lower doses to nearby healthy tissue. Some techniques deliver a higher dose of radiation to the patient each day, potentially shortening the overall treatment time and improving the success of the treatment.? IMRT may also lead to fewer side effects during treatment.
The radiation is delivered by a linear accelerator that is equipped with a multileaf collimator (a collimator helps to shape or sculpt the beams of radiation).? The equipment can be rotated around the patient so that radiation beams can be sent from the best angles.? The beams conform as closely as possible to the shape of the tumor.? Because IMRT equipment is highly specialized, not every radiation oncology center uses IMRT.
This new technology has been used at the Hughes Cancer Center for several years to treat tumors in the brain, head and neck, nasopharynx, breast, liver, lung, prostate, and uterus. PA oral cancer treatment is available with the use of IMRT; however, IMRT is not appropriate or necessary for every patient or tumor type.?
See also Hughes Cancer Center's SmartBeamTM IMRT page.
A number of refinements and techniques are in use or under study to improve the effectiveness of external radiation therapy. These are described below:
Three-dimensional (3-D) conformal radiation therapy. Traditionally, the planning of radiation treatments has been done in two dimensions (width and height). Three-dimensional (3-D) conformal radiation therapy uses computer technology to allow doctors to more precisely target a tumor with radiation beams (using width, height, and depth). Many radiation oncologists use this technique. A 3-D image of a tumor can be obtained using computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), or single photon emission computed tomography (SPECT). Using information from the image, special computer programs design radiation beams that conform to the shape of the tumor. Because the healthy tissue surrounding the tumor is largely spared by this technique, higher doses of radiation can be used to treat the cancer. Improved outcomes with 3-D conformal radiation therapy have been reported for nasopharyngeal, prostate, lung, liver, and brain cancers.
Internal radiation therapy (also called brachytherapy) uses radiation that is placed very close to or inside the tumor. The radiation source is usually sealed in a small holder called an implant. Implants may be in the form of thin wires, plastic tubes called catheters, ribbons, capsules, or seeds. The implant is put directly into the body. Internal radiation therapy may require a hospital stay.
Internal radiation is usually delivered in one of two ways, each of which is described below. Both methods use sealed implants:
- Interstitial radiation therapy is inserted into tissue at or near the tumor site. It is used to treat tumors of the head and neck, prostate, cervix, ovary, breast, and perianal and pelvic regions. Some women treated with external radiation for breast cancer receive a booster dose of radiation that may use interstitial radiation or external radiation. Growing in popularity, prostate cancer brachytherapy has proven to be a very effective treatment. In this treatment, the use of target source implants called prostate seeds make the radiation process possible.
- Intracavitary or intraluminal radiation therapy is inserted into the body with an applicator. It is commonly used in the treatment of uterine cancer. Researchers are also studying these types of internal radiation therapy for other cancers, including breast, bronchial, cervical, gallbladder, oral, rectal, tracheal, uterine, and vaginal.
For more information, see the High Dose Rate (HDR) Brachytherapy section
Systemic radiation therapy uses radioactive materials such as iodine 131 and strontium 89. The materials may be taken by mouth or injected into the body. Systemic radiation therapy is sometimes used to treat cancer of the thyroid and adult non-Hodgkin's lymphoma. Researchers are investigating agents to treat other types of cancer.
Radiation- Energy released in the form of particles or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, and medical X-rays.
Radiation fibrosis?- The formation of scar tissue as a result of radiation therapy.
Radiation nurse?- A health professional who specializes in caring for people who are receiving radiation therapy.
Radiation oncologist - A doctor who specializes in using radiation to treat cancer.
Radiation physicist - A person who makes sure that the radiation machine delivers the right amount of radiation to the correct site in the body. The physicist works with the radiation oncologist to choose the treatment schedule and dose that has the best chance of killing the most cancer cells.
Radiation surgery?- A radiation therapy technique that delivers radiation directly to the tumor while sparing the healthy tissue. Also called radiosurgery and stereotactic external beam irradiation.
Radiation therapist (RT) - A health professional who gives radiation treatment.
Radiation therapy - The use of high-energy radiation from X-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that circulates throughout the body. Also called radiotherapy.
