Radiation Oncology at Hoag

When undergoing radiation treatment, at Hoag, you are not alone. Hoag Family Cancer Institute has the most options for advanced radiation therapy available anywhere, along with in-depth experience operating it – so we can help you beat cancer.


Advanced Experience, Treatments & Technology

Radiation Treatment Second to None

At Hoag, you have access to the most advanced radiation therapy on the market – the ViewRay MRIdian linear accelerator – administered by experienced radiation oncologists. Hoag was the first in OC and second in the state to offer the MR Linac and has since treated more than 2,000 patients, a level of experience unmatched in Southern California.

Learn more about the adaptive ViewRay MRIdian

The Most Advanced Treatment Options

Not all treatments are right for everyone. At Hoag Family Cancer Institute, you’ll find the widest range of radiation therapy options available anywhere to ensure that your course of treatment is tailored to you.  

Radiation treatments available at Hoag include: 

Learn about other Radiation Treatment Options

Your Dedicated Team

Hoag Radiation Oncology has a comprehensive team including five radiation oncologists, six physicists, five dosimetrists and seven registered nurses – working together to give you the very best odds at overcoming cancer, healing and moving forward with your life. 

Meet the Radiation Oncology Team

Conveniently Located in OC

Hoag Radiation Oncology has locations in both Irvine and Newport Beach, so you will not have to travel far for treatment. 

Find a Location Near You

Frequently Asked Questions

The following is a list of frequently asked questions regarding radiation oncology treatment. Please feel free contact us at 949-764-5528.

Radiation Therapy is the use of high energy radiation (primarily x-rays) to kill cancer cells. Radiation Therapy can be used in combination with surgery, chemotherapy and/or biologic therapy to cure patients with cancer, control their disease or palliate symptoms. Radiation is also used to treat some benign tumors and selected neurologic disorders.

Since the discovery of radioactivity and x-rays, scientists have realized that radiation can shrink or eliminate tumors. Radiation acts against the genetic material in cancer cells, stopping their ability to grow and divide. Unlike cancer cells, normal tissue tends to heal from radiation damage and stay healthy despite some exposure. Radiation doctors use advanced technologies and knowledge of how cells respond to focus treatments of radiation, maximize the destruction of cancer, and minimize side effects.

Radiation Therapy can be used to treat almost any type of cancer, anywhere in the body. Commonly treated diseases include: tumors of the brain, breast, lung, prostate, larynx, stomach, pancreas, cervix, uterus, and soft tissue sarcomas. Radiation can be directed at the primary tumor site, or at sites where cancer has spread distantly (metastatic disease). Depending on the circumstances of each case, the goal of radiation therapy may be to cure a patient of cancer, to control their disease, or to palliate symptoms. About half of all patients with cancer receive some form of radiation.

Radiation can be used alone, or in combination with other treatment modalities such as surgery or chemotherapy. When combined with surgery, radiation may be used preoperatively, in order to shrink a tumor and make it easier to remove. Radiation can also be used postoperatively, in order to destroy any potential remaining cancer cells. When combined with chemotherapy, radiation can be used to make treatment more intense in the areas that are at highest risk for recurrence. In addition, radiation often works synergistically with chemotherapy or other drugs, killing more cancer cell when given together than either treatment would otherwise kill alone.

All forms of radiation therapy use ionizing radiation. However, many different delivery methods have been developed. For example, external beam radiation therapy uses radiation generated by a machine, which is external to the body. In contrast, brachytherapy uses radioactive sources, which are implanted in the body.

Each of these methods uses specially named technologies, such as 3D Conformal Radiation Therapy (3DCRT), Image-Guided Intensity-Modulated Radiation Therapy (IG-IMRT), ViewRay MR Linac Image-Guided Therapy, Tomotherapy Helical Therapy, Volumetric Arc Therapy (VMAT), Stereotactic Radiation Therapy (SRT) / Stereotactic Body Radiation Therapy (SBRT), Stereotactic Radiosurgery (SRS), Surface Guided Radiation Therapy (SGRT), Gamma Knife Perfexion Stereotactic Radiosurgery, Prostate Brachytherapy, High Dose Rate Brachytherapy – (HDR), Intra-operative Radiation Therapy (IORT), and  Accelerated Partial Breast Treatment (APBT). There are strengths and weaknesses to each technology, and no one technology is best for every patient.

Your radiation oncologist will discuss which technology is best suited for your needs. Learn more about each of Hoag’s innovative treatment options.

Radiation Therapy can cause irritation of normal tissue, resulting in acute (short term) side effects. These side effects depend on the area of treatment and the dose of radiation given. Potential acute side effects include: fatigue, skin reaction, hair loss (in the treated area), nausea, diarrhea, decrease in appetite, irritation to the esophagus, bladder or bowels, and the blood counts. Most side effects can be lessened with medications, and resolve within a few weeks after treatment. Many patients complete their treatments with little or no difficulty. Long term complications are less common, and each patient’s radiation plan is designed to minimize these risks.

Radiation therapy patients are often concerned that they will become radioactive from their treatment. The majority of patients are treated with techniques that leave no radiation behind in the body. These patients will not emit radiation, and pose no risk of exposing their family or other contacts. However, some patients are treated with radioactive implants (most commonly in the prostate), which emit radiation locally. These patients are counseled about certain precautions, although the level of emission is generally very low.

Your radiation oncologist and radiation oncology nurse will discuss all potential side effects with you before you begin treatment.

Your treatment process begins with a consultation with a radiation oncologist, where you will discuss treatment options and side effects. The next appointment is called a simulation. This is a set-up appointment, where you will be positioned for treatment, and a CT scan will be taken to acquire a three-dimensional image of the treatment areas for virtual planning. To identify the treatment position, your radiation therapist may place marks on your skin, including a few permanent dots, called tattoos, or non-permanent marks covered with clear protective stickers. 

In addition you may need an immobilization device, which will be made at this time. After the simulation appointment, your radiation oncology team will complete a planning and quality assurance process, which usually takes several days but may take up to two weeks depending on the complexity of your treatment plan. If needed, you may or may not return for a follow-up simulation to confirm your treatment set-up with the treatment plan.

Once all aspects of your treatment have been reviewed and checked your treatment will begin. Treatments are delivered daily, Monday through Friday. After you have finished treatment, your radiation oncologist will ask you to come in for follow-up appointments.

These devices are used to assist in your daily set-up and for your comfort in holding the position needed for your radiation treatments. The body-fix and vac-lock devices are made of tiny beads held in a plastic coating. The device forms to your body as air is taken out of the bag. If required, they are made during your simulation appointment.

Plastic mesh masks (for the head area) are made from a hard plastic that becomes very flexible when heated in a special oven. When it is heated to the proper temperature, it conforms to the contour of your face. It will harden and form very quickly. The masks are important for accurate daily set-up. If a mask is made for you, the marks will be placed on the mask, rather than on your skin. In the simulator and the treatment room, laser beams are used to help confirm your precise alignment. These laser beams are harmless.

Your simulation may take 45 to 75 minutes, depending upon the area being treated, the number and types of immobilization devices required, and the number of  CT scans needed to create your treatment plan.

Your Radiation Oncologist will request a treatment planning CT (or CAT SCAN). It is important to note that not all patients require a treatment planning CT. A treatment planning CT is not the same as a diagnostic CT. If an immobilization device was made, it will be used during your CT scan. Before or during your CT scan, you may be given an injection of a special dye that helps us to see certain organs on the CT scan. The information from your CT will be put into our treatment planning computer system and will be used to determine the type of treatment field, energy and beam angle for your radiation treatments.

On your first day, the radiation therapists on the treatment machine will take images to verify positioning and the treatment field. These images may include a mini-CT scan, x-rays, or both depending on the doctor’s request. These images are very important and are used to compare to the scan taken during your simulation to ensure the accuracy of the treatment set-up. Once these have been taken your treatment will be delivered. During your radiation treatment you will not see or feel anything. Although you are in the treatment room alone, the therapists are monitoring you through the use of an intercom and a closed circuit television system.

The time spent on the treatment table will vary depending on the treatment technique and treatment equipment used. The time will vary between 10 minutes and 1 hour. Your therapist will tell you how long to plan daily. Your daily appointment schedule is determined on this day. The therapists will work with you to find a time that will satisfy your needs as well as the current schedule on the treatment machine. In general, your treatment time will remain the same from day to day. If, from time to time you need this daily time to be altered, your therapist will work to reschedule you.