What is Radiation Therapy?
Radiation therapy is the use of various forms of radiation to treat cancer. Radiation therapy works by damaging the genetic material within cancer cells and limiting their ability to successfully reproduce. Radiation therapy is local therapy which affects cells within a specific, defined area. Normal cells are also affected by radiation, but they are able to repair themselves in a way that cancer cells cannot. Radiation therapy may be used alone or in combination with other therapies such as chemotherapy, biological therapy or surgery.
What can Radiation Therapy do?
Depending on the type of cancer and how advanced it is, radiation therapy can be used for different goals:
- To cure the cancer (cancer is considered cured when the patient remains free of evidence
of cancer cells).
- To make the tumor smaller in a specific area of the body.
- To control the cancer by keeping the cancer from spreading, slowing the cancer's growth and
killing cancer cells that may have spread to other parts of the body from the original tumor.
- To relieve or palliate symptoms that the cancer may cause. Radiation therapy can be used to
shrink tumors, reduce pressure, pain and other symptoms of cancer.
How is Radiation Therapy given?
Radiation therapy can be given externally (outside the body) or internally (inside the body). Some patients have both. Radiation therapy is usually given during outpatient visits to the cancer center.
External Beam - Radiation generated externally by a linear accelerator directed to a specific area of the body. Treatment days vary between 10-42 daily treatments dependent upon diagnosis and intent of treatment. On average, treatments take about 15-20 minutes daily.
Brachytherapy - Radiation is given placing radioactive sources inside the body.
- High dose rate - involves placing radiation source into catheter from a remote afterloading machine.
- Accelerated Breast Irradiation
- Gynecologic Implants
- Low dose rate - placement of temporary or permanent radiation sources into the tumor area.
- Prostate Seed Implants
- Low Dose Gynecologic Procedures
Stereotactic Radiosurgery - A specialized type of external treatment which delivers precise high dose targeted radiation to a specific area. This type of treatment increases dose to a site while minimizing dose to normal tissue.
- SBRT - Stereotactic Body Radiation Therapy - generally 1-5 treatment. Average treatment time is 1 hour - used primarily for tumors in the lung and abdomen.
- SRS - Stereotactic Radiosurgery - generally one treatment to tumors of spine and brain.
Who is the Radiation Therapy team?
- The radiation oncologist is a doctor who specializes in using radiation to treat cancer.
- The radiation physicist makes sure the equipment is working properly and the machines deliver the right dose of radiation.
- The dosimetrist helps carry out your treatment plan prescribed by your radiation oncologist by calculating the amount of radiation to be delivered to the cancer and normal tissues that are nearby.
- The radiation therapist gives the daily radiation treatment, maintains daily records and regularly checks the treatment machines, making sure they operate correctly.
- The radiation nurse coordinates care, helps you learn about treatment and manage side effects. The nurse can also answer questions you or family members may have about your treatment.
What are the side effects of Radiation Therapy?
The brief high doses of radiation that damage or destroy cancer cells can also injure or kill normal cells. These effects of radiation on normal cells cause treatment side effects. Most side effects of radiation treatment can be reduced with help from your health care team.
- Most of the side effects of radiation therapy are located in the area being treated.
- The most common side effect of radiation therapy is fatigue.
- If you are experiencing side effects from your treatment, please let your healthcare team know. They may be able to provide strategies and therapies including: physical therapy and/or medications.
Questions to ask your doctor about Radiation Therapy:
- Why do I need radiation therapy?
- What are the benefits?
- What are the risks?
- Are there any other possible treatment methods for my type of cancer?
- What is the standard care for my type of cancer?
- Are there any clinical trials for my type of cancer? (please see clinical trials section for more information)
- How many treatments will I be given?
- What side effects can I expect from treatment?
Radiation Therapy Answers
The American Cancer Society
National Cancer Institute