Radiation Treatments

Nearly two thirds of patients diagnosed with cancer are treated with radiation (Physician Characteristics and Distribution in the U.S., 2010 Edition). Most patients are treated with a combination of radiation, surgery and/or chemotherapy, while some patients are treated with a single method.

Radiation treatment for cancer can be delivered in several ways, all designed to damage the DNA within cancer cells to stop tumor growth. The treatment technique used most often is external beam radiation therapy — also called radiotherapy. During radiotherapy treatment, the patient lies down on a treatment "couch", and the radiation is directed at the tumor from outside the body using a linear accelerator. Radiosurgery, a procedure that delivers larger radiation doses generally in one to five treatments, is typically delivered in the same way. With brachytherapy, radioactive material is placed in the body near tumor cells, or injected into the bloodstream.

Your radiation oncologist and clinical team will determine the most effective treatment technique for your particular case. Below, you can find basic information about what techniques are available, and how they differ from one another.

Radiation Therapy

  • Radiation therapy, or "radiotherapy," can be used to treat cancer almost anywhere in the body. Some of the most commonly treated cancers are prostate, lung, and breast, brain, rectum and bone (including spine).¹
  • Radiotherapy is typically delivered five days a week for four to six weeks.
  • It can be delivered using various treatment techniques including image-guided radiotherapy (IGRT) and intensity-modulated radiotherapy (IMRT). The latest techniques are developed and designed to help improve treatment accuracy and minimize dose to healthy tissue.
  • Most techniques may use a lower dose of radiation per treatment session compared to radiosurgery.
  • It is typically an outpatient procedure, meaning hospital stay is not required.

Learn more about: side effects, benefits, how it works, what to expect during treatment, questions to ask your doctor, or FAQs.


  • Radiosurgery, also known as stereotactic radiosurgery (SRS), or stereotactic body radiation therapy (SBRT), was first developed to treat tumors in the brain and spine. Now, radiosurgery is used to treat cancer almost anywhere in the body.
  • Radiosurgery typically involves using higher doses of radiation than conventional radiation therapy. Because the dose is more intense, treatment is delivered in only one to five treatment sessions.
  • Radiosurgery is most often used for small targets (typically under 4cm) that can be treated with a higher dose of radiation. It may also be used in cases where there is a recurrence of the cancer after radiation therapy has been used.
  • Due to a typically short recovery time, hospital stay is not required.

Learn more about: side effects, benefits, how it works, what to expect during treatment, questions to ask your doctor, or FAQs.


  • Brachytherapy is also known an internal radiation therapy, because it involves placing a radioactive source inside the body near the tumor or tumor bed (where a tumor was first removed surgically).
  • The number of brachytherapy treatments needed varies from patient to patient, depending on the stage of the cancer, the location of the tumor, and other health factors.
  • Brachytherapy is typically delivered in one of two ways: high-dose rate brachytherapy or low-dose rate brachytherapy. (See How Does Brachytherapy Work? for more details).
  • Treatment may be delivered on an outpatient or inpatient basis, depending on the type of brachytherapy technology used.

Learn more about: side effects, benefits, what to expect in treatment, questions to ask your doctor, or FAQs.

  1. Accessed 10-5-2010 [] Wang, C., M.D., ed. Clinical Radiation Oncology: Indications, Techniques, and Results. 2nd Edition. Wiley-Liss, Inc., 2000. 1-5.Also see the ASTRO Facts Sheet if you need more info: