The Basics of Radiation Therapy

Radiation therapy (also called radiotherapy) is a cancer treatment that uses very sophisticated technology to kill cancer cells. Radiation works to treat cancer through a number of biologic mechanisms, including interfering with the ability of cancers to divide and grow by affecting their genetic material.

Radiation therapy is delivered using very complex, high-tech equipment. There are two main types of radiation therapy: external beam radiation therapy (when a machine outside your body aims radiation at cancer cells) or brachytherapy (when a radiation source is placed inside your body to treat cancer cells). Radiation therapy is administered by an integrated team of health care professionals led by a Radiation Oncolgist, a physician specialized in the delivery of radiation therapy.

It is appropriate for some types of cancers to receive radiation therapy alone. For other types of cancers, radiation therapy may need to be delivered in coordination with other cancer therapies, such as surgery and/or chemotherapy.

Many people with cancer need radiation therapy. Statistics show that more than half of cancer patients receive radiation therapy.

Radiation treatments are designed to minimize radiation exposure to normal tissues. However, it is impossible to deliver therapeutic radiation doses to a patient's tumor without delivering some of that dose to normal tissues surrounding the cancer. This may result in normal tissue damage that can cause side effects. These potential side effects are managed by your Radiation Oncologist.

Radiation therapy does not kill cancer cells right away. It takes days or weeks of treatment before cancer cells start to die. Then, cancer cells keep dying for weeks or months after radiation therapy ends.

Once you have finished radiation therapy, you will need continued follow-up care with your Radiation Oncologist and other cancer care specialists. This may require a combination of physical examination, radiological studies (e.g., X-rays, CT scans, MRI scans, PET scans, etc.) and/or bloodwork. During your follow-up visits with your doctors, you will also be assessed for tolerance to cancer treatments, including management of any side effects that may have developed due to your cancer treatments.

Cancer Guide