Radiation therapy, or radiotherapy, uses high energy rays to treat tumors or cancer. Radiation damages the DNA of cancer cells, killing them or making it impossible for them to divide and for cancer to spread. Radiation therapy can be used alone or in combination with surgery or other treatments, such as chemotherapy. It is an option for tumors that cannot be easily accessed surgically, such as those at the base of the skull, and it can be used following surgical cancer treatment to remove remaining cancerous tissue and prevent recurrence of cancer. Sometimes radiation therapy is used as a palliative treatment to shrink tumors. Rather than cure your condition, palliative treatments treat symptoms, such as pain caused by spinal tumors and problems with eating or drinking caused by esophageal tumors.
The type of therapy you receive will depend on the size, type, and location of your tumor or cancer, as well as the sensitivity of the surrounding healthy tissue, your age, and your medical history. Radiation treatment may be delivered in two ways:
- Internally, meaning radioactive material is placed inside of your body. Brachytherapy is a commonly used method of internal radiation therapy. Using catheters or needles, radioactive seeds or pellets are placed inside the body, and over the course of several weeks or a few months, the seeds will deliver radiation. Permanent brachytherapy leaves the seeds in your body permanently without causing side effects while temporary brachytherapy removes them after a treatment session.
- Externally, using a machine that aims radiation beams outside of your body. External radiation therapy is also known as external beam radiation therapy (EBRT). There are several types of EBRT, which differ in intensity and type of beams used. EBRT can be done before surgery (preoperatively), during surgery (intraoperatively), or after surgery (post-operatively).
Before you undergo radiation therapy, a team of medical professionals, including a radiation oncologist, will work with you to determine a treatment plan. This will involve mapping the area around the tumor or cancer, determining proper positioning for treatment delivery, and determining dosage. Treatment delivery will occur in sessions over the course of several weeks or months, depending on the type and size of cancer and its location in the body, among other factors.
Although radiation therapy aims to target only cancerous cells, damage to normal healthy cells may occur. You might experience side effects from radiation during treatment or in the months and years following it. They are dependent on the areas treated and may include fatigue, nausea, vomiting, skin irritation, hair loss, memory loss, and infertility. Your oncologist will take into account the amount of radiation that different areas of your body can receive safely while determining your treatment plan.