What to Expect with Radiation Therapy

What to know before, during and after radiation treatment

A middle-aged woman talks to a Scripps radiation oncology team, representing what happens before, during and after radiation treatment.

Dr. Kenneth Shimizu, Scripps Cancer Center, Scripps Clinic

What to know before, during and after radiation treatment

Radiation therapy is a powerful cancer treatment, but most patients tolerate it well. Advances in radiation therapy technology have resulted in much more precise targeting of cancer cells, with less impact on nearby healthy cells and fewer side effects as a result of treatment. If you’re receiving radiation therapy at Scripps Cancer Center, here’s what you can expect before, during and after treatment.

Preparing for treatment

Before you begin treatment, you’ll go through several steps to determine the most appropriate radiation treatment plan for your cancer type and stage, as well as your overall health and lifestyle.

External beam radiation therapy

Most patients will receive external beam radiation therapy, which treats cancer from outside of the body. Radiation beams are delivered by powerful, precise equipment in one of our hospitals or radiation therapy centers. Most patients need several treatments per week. The number of weeks depends on the type and stage of cancer.


Scripps cancer specialists use several types of external beam radiation therapy:

  • Electron beams
  • 3-D conformal radiation therapy (3-D CRT)
  • Intensity-modulated radiation therapy
  • Image-guided radiation therapy
  • Stereotactic radiosurgery (SRS)
  • Stereotactic body radiotherapy/stereotactic ablative radiotherapy (SBRT/SABR)
  • Total body irradiation

Generally, each radiation treatment takes about 15 minutes. But this may vary based on the type of radiation therapy, the need for imaging scans and other factors. Your radiation oncologist can tell you more specifically how long each treatment will take.

Depending on your individual needs and the type of radiation therapy you’re having, you may have just a few treatments, or you may need multiple treatments over a number of weeks. Most patients have daily treatments Monday through Friday for five to eight weeks, but your schedule may be different.

Internal beam radiation therapy

Internal beam radiation therapy, most commonly called brachytherapy or seed radiation, delivers radiation by placing radioactive substances directly into or near a tumor. Radioactive beads, wires or other sources are placed into the body through catheters or small plastic tubes. 

Scripps offers high-dose brachytherapy, which delivers a high dose of radiation internally for a very short time per treatment. The radioactive substance is placed into the body and removed after a few minutes. Treatments may be repeated for several days or weeks.