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 Offered Through Maryland Oncology Hematology’s White Oak Cancer Center
At Maryland Oncology Hematology’s White Oak 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
The physician and staff at White Oak Cancer Center will guide you through each step of the radiation treatment process, from initial consultation to follow-up care. These steps include:
- Consultation – Your radiation oncologist will meet with you to review your records and discuss your individual care plan.
- Simulation – AO staff will perform a CT scan and administer markings on your body to map out your treatment area.
- Treatment Planning – Your radiation oncologist will then determine the exact area of your body to be treated and the amount of radiation necessary.
- Radiation Treatment – Your radiation therapy will be administered over a course of two-to-eight weeks, depending on your treatment plan.
- Follow-up care – Your AO doctor will provide details about how to care for the areas treated with radiation and any possible side effects. They will be available after your treatments have finished if you have any questions or concerns. As with all members of AO, your radiation oncologist is with you from diagnosis through survivorship, and everything in between.