Understanding Radiation Therapy
Radiation therapy is one of the most common treatments for cancer, and roughly half of all cancer patients receive radiation during the course of their illness. Radiation can be used alone or in combination with other treatments such as surgery, chemotherapy, and immunotherapy.
Radiation therapy uses high-energy beams or particles to kill or damage cancer cells. It plays an important role in treating certain cancers and easing cancer symptoms, including the treatment of lung, breast, prostate, and head and neck cancers.
Although you may experience some mild side effects during treatment, radiation therapy is usually painless. Some patients may experience fatigue, sensitive skin at the treatment site, and emotional distress. When radiation is used to treat advanced-stage cancer, it may cause nausea and vomiting, especially if treatment involves the liver, brain, or gastrointestinal tract. The chance for nausea grows as the dose of radiation and the size of the treatment area increase. Unlike chemotherapy, which frequently causes hair loss, patients undergoing radiation therapy will not lose their hair unless treatment is targeted at the head.
Types of Radiation Therapy
At Southern Cancer Center, our radiation oncology team offers external radiation and internal radiation.
External beam radiation is the most common type of radiation therapy. It delivers radiation from a machine outside the body, focusing high-energy rays into the tumor. Advanced computer software regulates the beam’s size and shape, targeting the tumor while minimizing exposure to healthy tissue near the cancer cells. The machine does not touch the patient, but it can rotate around the treatment table. Treatment sessions are usually done as outpatient visits over several weeks or months.
Internal radiation, sometimes called brachytherapy, involves putting a radioactive source directly into the body. Solid radiation sources are put into seeds, ribbons, or capsules and placed inside the body, near or directly in the tumor. These implants may be permanent or temporary. Internal radiation therapy may also use a liquid radiation source given through an injection, by mouth or with an IV line into a vein to treat certain types of cancer. These drugs then travel throughout the body, attacking cancer cells.
Our radiation oncologist will work with you to determine which type of treatment is best for your diagnosis. This may include:
- Image-Guided Radiation Therapy (IGRT) combines three-dimensional images to pinpoint and treat cancerous tumors. The images allow the cancer specialists to precisely localize the tumor each time radiation therapy is administered, improving accuracy of delivery and safety by reducing radiation exposure to other areas of the. IGRT is used to treat tumors in areas of the body that are prone to movement, such as the lungs, liver, and prostate gland, as well as tumors located close to critical organs and tissues.
- Intensity-modulated radiation therapy (IMRT) is an advanced form of external radiation treatment that allows precise targeting of tumor cells using 3D planning. With IMRT, the radiation oncologist specifies the dose desired to give the tumor and the doses acceptable to the normal tissues (as low as possible). Then the computer system provides millions of alternative beam positions and the varying intensities of each beam, comparing one plan to the next until the best plan is identified.
- Stereotactic body radiotherapy (SBRT) is an advanced type of radiation therapy that delivers high doses of radiation using several beams of varying intensity aimed at a very targeted area of the body. Due to the high intensity of the radiation dose, only one to five doses are given over a single day. Three-dimensional images are used in the simulation process to direct the beams precisely while reducing radiation exposure to other areas of the body. Patients with small, well-defined tumors who cannot tolerate surgery are good candidates for SBRT.
- Stereotactic radiosurgery (SRS) is a type of stereotactic radiation therapy that can be used in place of or in conjunction with surgery for single tumors that have spread to the brain. It is given in one session, although the treatment can be repeated if necessary. There are two possible SRS treatments. In one, a machine focuses approximately 200 beams of radiation on the tumor from different angles while the patient’s head is kept in the same position. In the other version, a computer-controlled linear accelerator moves around the patient’s head to deliver radiation to the tumor from different angles.
- High-dose rate (HDR) brachytherapy delivers high-doses of radiation to the tumor area from within the body or on the surface of the skin. It is administered through an applicator tube or thin catheter that is inserted into the body or through an applicator that sits on top of the skin. This process delivers radiation for several minutes to the specific area where the cancer is located, sparing surrounding tissue. The radiation is removed from the body, unlike low-dose brachytherapy which may stay implanted.
- Low-dose rate (LDR) brachytherapy delivers radiation using a radioactive device or implant placed inside the body. The device delivers a low dose of radiation to a limited area over a period of 20 to 50 hours. It is one of the most focused, precise forms of radiation therapy and spares much of the surrounding tissue. LDR can be used to treat various cancer sites, such as prostate, uterus, or cervix.
The Treatment Process
Our staff will guide you through each step of the radiation treatment process, from initial consultation to follow-up care. These steps include:
- Consultation – At the time of consultation, the radiation oncologist will review your records, X-rays, scans and other test results and perform a physical examination. It may be decided that additional tests are needed and that will be discussed with you. The radiation oncology nurse will work closely with you and the radiation oncologist during the initial consultation. If the radiation oncologist believes that you will benefit from radiation therapy, a treatment plan will be presented to you during the consultation, based on the results of the evaluation.
- Simulation & Treatment Planning – Once you and the physician decide to move forward with the proposed radiation therapy plan, treatment planning begins. A treatment plan, which is a collection of measurements, imagery and dosing calculations, will be developed specifically for each patient so that the post-treatment results are the best that they can be. This custom-made plan is influenced by overall health, type and stage of cancer. It also takes into consideration information from other specialists. You will undergo a special CT scan called a “simulation”. The imagery and information acquired during the simulation will allow the physician to target the tumor and avoid the other organs and healthy tissues nearby. Treatment will usually take place daily over several days or weeks. To ensure that you are in the exact same position for every treatment, specialized equipment may be used to help hold you in place. Small temporary ink marks may be drawn on the skin to assist the therapists with body alignment. You will have an education session with a nurse before treatment begins. During this session, you will receive advice on self-care during treatment, proper eating habits, ways to avoid infection, skin care protection, what to report to the physician or nurse, sources of support and an overview of the clinic. Once treatment begins, you will be assessed by the nurse and physician per protocol. The nurse is often the first line of communication for our patients.
- Starting Daily Treatments – When the planning is complete, you will be treated with one or more machines that will deliver the radiation to your prescribed location. These technologies generate high energy X-rays or electrons that destroy tumor cells. Other systems are designed to deliver radiation through the use of isotopes and catheters. Radiation therapists, who are certified by the American Registry of Radiologic Technologists (ARRT), administer the daily treatment under the supervision of the radiation oncologist. They record and document treatment progress and run tests on the treatment machines daily to ensure that they are working properly. Most radiation treatments are given five times a week, Monday through Friday.
- Care During Treatment – Most people undergoing radiation treatment are able to continue with their normal activities. Some may need to adjust their level of activity temporarily during treatment if recommended. Patients are encouraged to check with their doctor before starting any exercise or fitness program during this time. Good nutrition during therapy is essential to promote healing and recovery, and your oncology care team can help determine the best approach. Patients are weighed regularly during radiation therapy to monitor health and weight loss. Patients should do their best to eat a normal, well-balanced diet with three or more regular meals. Smaller, more frequent meals and snacks may also be suggested. Patients should also consult with their doctor about the use of multivitamins and other dietary supplements. This type of information is also available through the oncology nurse.
- Follow-up Care & Ongoing Support – Once you have finished a course of treatment, follow-up care instructions will be reviewed and you will return for follow-up appointments. These may involve blood work or imaging to determine the outcome of the treatment. Due to the multidisciplinary team approach used to treat cancer patients, other physicians may also be involved in your follow-up care (i.e. medical oncologist, other specialists, surgeon, primary care physician). As with all members of Southern Cancer Center, your care team is with you from diagnosis through survivorship, and everything in between.
To learn more or to schedule an appointment, please call us at 251.625.6896.