Radiation Oncology – What to Expect

We will do our best to make the process of your radiation treatment as clear and manageable as possible. This page explains what you can expect and who you will meet during each of these visits.


Your treatment process begins with a consultation visit with your radiation oncologist and other key members of your treatment team. They will review your treatment choices, explain possible side effects from your treatment, address any questions and concerns you and your family may have, and obtain your consent to proceed with your personalized treatment plan and schedule. This visit usually takes about an hour.

The radiation oncologist may communicate a great deal of information to you during the consultation visit. You may want to prepare a list of questions prior to the visit. You may also want to bring another person to the consultation to help record and understand the information provided.

Treatment Planning

The next step is to plan the radiation therapy through a process known as “simulation.” During this phase, your treatment team will collect visual information to determine your optimal treatment plan utilizing specialized imaging devices, such as a Computed Tomography (CT) scanner. The images created enable your team to map out the exact location of the tumor and the area to be treated. The scanning process may require using contrast, a material that helps make the images clearer and more useful for planning your treatment. The simulation process will also determine and record the optimal body positioning for you during your treatment. Special devices, such as molds and masks, are often created or custom-fitted to keep your body in the correct position. Your radiation therapist may also apply a tiny permanent tattoo to your skin, which is used to ensure precise body position and beam angle for each treatment.

After your simulation appointment is complete, the images are transferred to a planning system and a 3-dimensional image of the treatment area is created. Your team will then review your information and design your personalized treatment plan with the help of sophisticated computer software.

Of all your visits to the radiation oncology department, the simulation session may require the most time. After the simulation process is concluded, it may take up to two weeks for your team to complete the treatment planning prior to commencing treatment.


The first appointment in the treatment phase is dedicated to orienting you to the department and double-checking the plan that was designed for you during the Treatment Planning phase. When you arrive for this session, your team, including medical assistants and administrative assistants, will review check-in procedures and other logistics. You may be asked to change into a hospital gown for your treatment, depending on the area of your body being treated. Family or friends may accompany you, but they will need to wait in the waiting area during the treatment session.

You will be taken into the treatment room for a practice or “dry run” of the plan to recheck the measurements that were taken during the Treatment Planning phase. The treatment room contains a specialized machine called a linear accelerator (LINAC) that will be used to administer the treatment that was designed for you. For both the “dry run” and the actual treatments, the therapists will place you in the exact position you were in during the planning session by using any devices and skin marks that were created during the simulation. Treatment begins only after the radiation oncologist and therapists have rechecked the treatment field and calculations to make sure your treatment plan is precisely followed. Treatment may begin either that day or the following day.

During each treatment, you must lie very still on the treatment table while the radiation beam is targeted to the area of the tumor. The treatment machine may rotate up to 360 degrees around you to enable the radiation to hit the tumor from optimal angles. The therapists will always leave the room before radiation begins, but they will watch you constantly on a television monitor and use an intercom to speak with you throughout your radiation treatment. Treatment sessions vary in length, but most are between 10 and 20 minutes long. The number of treatments that you will have depends on the type of cancer that is being treated.

You will feel no pain during the treatment and the treatment does not make you radioactive. You can leave and go back to normal activities as soon as the session is over.

Please note that we provide free parking for patients during treatment sessions. Please ask about this at check-in.


Towards the end of your radiation treatments, your radiation oncologist will discuss an individualized plan for follow-up. In general, you will continue to see your radiation oncologist and/or members of their team on a regular basis to assess the response to the treatment and monitor and treat any side effects. Should you have any questions or concerns between these scheduled appointments, we encourage you to contact your oncology team.

Your Treatment Team

Your treatment team will include highly skilled and experienced physicians and other health care professionals who work together seamlessly to ensure you receive safe, personalized and effective care customized to your specific disease:

  • Radiation Oncologists who oversee your radiation treatment in close coordination with other specialists from medical oncology and/or surgical oncology. Meet our world-class Radiation Oncologists.
  • Radiation Oncology Nurses who provide personalized care alongside the physicians in disease-specific practices
  • Medical Physicists who are responsible for the overall safety of the equipment and accuracy of the treatment
  • Dosimetrists who calculate the size, shape and arrangement of the area that will receive the dose of radiation
  • Radiation Therapists who administer the radiation treatments that your radiation oncologist prescribes
  • Resident Physicians and Clinical Fellows who are involved in all aspects of patient care under the guidance of an attending supervisor

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