Radiation Oncology

Radiation therapy is a treatment for cancer. It works by administering radioactive energy that keeps cancer cells from growing and dividing, causing them to die. Each of our patients gets a custom radiation plan to carefully target their cancer while limiting the effects on healthy tissue.

Preparing for Radiation Treatment

Your first appointment with our team is an initial consultation to find out if radiation oncology is appropriate for you. During this meeting you discuss radiation treatment, how it may help you and how to prepare. It’s a good idea to bring someone with you who can help remind you of any questions you have and write down answers to your questions.

If you’re prescribed radiation therapy, your next visit includes a CT simulation scan. You may need to limit food or drink before the simulation. Your care team will let you know how to prepare.

During a CT simulation scan:

1. You may receive an intravenous (IV) line with contrast, or you may need to drink a small amount of contrast. Contrast helps certain areas of your body show up more clearly on the scan.
2. You lie on a long and narrow table.
3. The radiation therapist positions you in the same way you’ll need to lie during treatment.
4. The table slides inside a donut‑shaped machine called a scanner. The machine rotates around you to take images.
5. Your radiation therapist may ask you to hold your breath or stay in certain positions during the scan. They may also reposition you.
6. We may create a small body or face mold to ensure this correct positioning during your treatment.

After the scan, we place small markings on your skin that help with alignment during treatment. We collect the images and send them to a physicist for planning with your radiation oncologist.

After the scan, it takes about three to seven business days to develop a customized treatment plan. Our team offers the full spectrum of radiation therapy treatments so you can have the best chance of a successful outcome.

Your treatment plan may include the following treatments:

• Brachytherapy
• External beam radiation therapy
• Intensity‑modulated radiation therapy (IMRT)
• Respiratory gating and motion management
• Stereotactic radiosurgery (SRS)
• Total‑body irradiation

First, your radiation oncologist gives a dosimetrist or medical physicist a prescription for your treatment. Your prescription includes:

• How much radiation you need
• What area to target
• The best type of radiation treatment to use

The dosimetrist or physicist uses your CT simulation images to prepare a treatment plan that meets the prescription determined by your radiation oncologist. They make calculations to figure out the best method for delivering the prescribed dose of radiation. How many treatment sessions you need will vary depending on your cancer type and your radiation oncologist’s prescription.

When your plan is ready, you will receive a call letting you know the day and time of the first treatment. When you come for the first treatment, you will be given a schedule of the remaining days and times for your radiation therapy.

On your first day of treatment, we show you the machine that will be used for your radiation therapy. Your radiation therapist explains the treatment setup and process.

On the days of your radiation treatment sessions:  

1. You check into the clinic and change into a gown for treatment.
2. Once in the treatment room, the radiation therapist positions you the same as during the CT scan, making sure you are aligned correctly each time.
3. The therapist leaves the room to administer the radiation. It’s normal to see the radiation machine move and hear noises from it throughout your session.
4. Your therapist monitors you from a control room and can see and hear you via video and intercom.

A radiation therapist delivers your ongoing treatment. You have weekly check‑ins with your doctor to check on any side effects or changes in your health. Even though you won’t see the doctor every day, your doctor communicates closely with your radiation therapists and reviews any X-rays obtained during your treatment.

After you’ve completed radiation treatment, the effects of radiation continue to work in your body to destroy cancer cells. The side effects should go away gradually. We monitor any side effects during your follow‑up visits.

Throughout your treatment, you also benefit from a range of resources, including:

• Supportive care: Our Supportive Care Medicine Program offers a range of services to keep you as comfortable as possible throughout cancer treatment. You have access to spiritual care, support groups and a dedicated social worker.
• Clinical trials: Cedars‑Sinai doctors are also active researchers. You may be eligible for new, leading-edge therapies and treatment methods through clinical trials.
• Recovery support: If you’re in remission or recovering from cancer, our Survivorship Program offers multiple resources. You have access to nutrition counseling, physical therapy and exercise classes to help you recover well.