Internal. External. IMRT. IGRT. What exactly is radiation therapy?
At OHC, we aggressively attack your cancer with leading-edge approaches and therapies, and we make sure you are included in your care plan discussion and understand every step of that plan. If you receive a cancer diagnosis, radiation therapy may be recommended as part of your treatment plan. You may hear terms like external versus internal, liquid versus solid, and an alphabet soup of IMRT, IGRT, CRS and SBRT. We know this can be confusing, so my OHC colleagues and I want to provide information so you understand what each is and how it may be used in your care.
Radiation therapy is a type of cancer treatment that uses high doses of radiation to kill cancer cells or stop their growth. At high doses, radiation therapy kills cancer cells or slows their growth by damaging their DNA. Cancer cells whose DNA is damaged beyond repair stop dividing or die. When the damaged cells die, they are broken down and removed by the body. Radiation therapy does not kill cancer cells right away. It takes days or weeks of treatment before DNA is damaged enough for cancer cells to die. Then, cancer cells keep dying for weeks or months after radiation therapy ends.
As noted, there are two main types of radiation therapy, external and internal. The type of radiation therapy you receive depends on several factors including:
- The type of cancer
- The size of the tumor
- The tumor’s location in the body
- How close the tumor is to normal tissues that are sensitive to radiation
- Your general health and medical history
- Whether you will have other types of cancer treatment
- Other factors, such as your age and other medical conditions
External radiation therapy
External radiation therapy comes from a machine that aims radiation at your cancer. It’s a local treatment, which means it treats a specific part of your body. For example, if you have cancer in your lung, you will have radiation only to your chest, not to your whole body.
There are many types of external beam radiation therapy, all of which share the goal of delivering the highest prescribed dose of radiation to the tumor while sparing the normal tissue around it. The types of external radiation include intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT), Tomotherapy, Stereotactic radiosurgery (SRS), and stereotactic body radiation therapy (SBRT).
Internal radiation therapy
With internal radiation therapy, a source of radiation is put inside your body. The radiation source can be solid or liquid.
Oral: the treatment travels in the blood to tissues throughout your body, seeking out and killing cancer cells. You may have liquid radiation therapy by swallowing it, through an IV inserted in a vein, or through an injection, or you may have capsules to swallow.
Solid: Internal radiation therapy with a solid source is called brachytherapy. In this type of treatment, seeds, ribbons, or capsules that contain a radiation source are placed in your body in or near the tumor. If you receive low-dose rate implants, the radiation source stays in place for 1 – 7 days. You are likely to be in the hospital during this time. Once your treatment is finished, your doctor will remove the radiation source and the catheter or applicator. If you receive high-dose rate implants, the radiation source is left in place for just 10 to 20 minutes at a time and then taken out. You may have treatment twice a day for 2 – 5 days or once a week for 2 – 5 weeks.
Sometimes radiation is used to ease symptoms. External radiation may shrink tumors to treat problems caused by the tumor, such as pain, trouble breathing or loss of bowel and bladder control. Pain from cancer that has spread to the bone can be treated with systemic radiation therapy drugs called radiopharmaceuticals.
The most important point to know about radiation therapy is that if your OHC doctor recommends it for your condition, you can rest assured they will:
- Explain in detail your cancer diagnosis and stage (the extent of the cancer)
- Develop, discuss, deliver, and direct all treatment options and a recommended treatment strategy
- Work with a multi-disciplinary care team who specialize in different areas of care and work together
- Maintain your quality of life by managing pain and other symptoms or side effects
- Discuss other non-clinical support you may need
To learn more about radiation and other treatments and services, please browse this web site or call OHC at 1-800-710-4674.
OHC (Oncology Hematology Care) has been fighting cancer on the front lines for more than three decades. We are the region’s leading experts in the treatment of nearly every form of adult cancer and complex blood disorder. OHC offers the latest medical, gynecologic and radiation therapy, and is always seeking better treatment options through participation in clinical trials. OHC is certified by the American Society for Clinical Oncology in the Quality Oncology Practice Initiative Certification Program, is an accredited Oncology Medical Home, and is one of only 179 practices nationally to be accepted into the Medicare Oncology Initiative. At its heart, our approach to cancer care is simple – to surround you with everything you need so you can focus on what matters most: beating cancer.
Sources: OHC, National Cancer Institute