Newark Radiation Oncology, Inc. How Radiation Therapy Works

How Does Radiation Therapy Work?

Radiation therapy is the use of various forms of radiation to safely and effectively treat cancer and other diseases. Radiation therapy is given in fractions or days, typically Monday thru Friday for several weeks depending on each patient’s unique prescription. Radiation therapy damages cells by destroying the genetic material that controls how cells grow and divide. Once this happens, the cancer cells are not able to grow and spread. When these damaged cancer cells die, the body naturally removes them. Normal cells are also affected by radiation, but they are able to repair themselves in a way that cancer cells cannot.


Before radiation therapy can be administered, the patient will visit with our Radiation Oncologist. He will review the medical history and give a physical exam to determine if the patient will benefit from radiation therapy. The Radiation Oncologist will also discuss the potential benefits and side effects of radiation therapy.

CT Simulation

During CT simulation you will meet with your radiation therapy team, healthcare professionals who work together to plan and provide your radiation treatment. Team members include:

  • A Radiation Oncologist, a doctor who specializes in treating cancer with radiation. The Radiation Oncologist determines the appropriate therapy for each patient, follows each patient’s progress and adjusts each patient’s treatment if necessary.
  • A Medical Physicist and Dosimetrist, make calculations and measurements regarding radiation dosage and its delivery.
  • Radiation Therapists, operate the radiation equipment and administers the radiation treatments.

Before the first treatment session, the patient will go through a radiation therapy planning session called CT simulation. During the simulation the Radiation Oncologist and Radiation Therapists will complete a CT scan (CAT scan) of the patient in an position which is best suited to target the affected area of the body and avoid damage to surrounding normal healthy tissue. The Radiation Oncologist and Radiation Therapists will select proper immobilization devices for the patient to hold and maintain a position which is reproducible, accurate, and comfortable for the patient for every treatment. The Radiation Therapists will mark the patient’s body at specific points with semi-permanent ink or with tiny tattoo dots. These marks will guide the Radiation Therapists in administering the radiation when the patient returns for the daily treatments. You will be asked to avoid scrubbing away these marks, they are very important. When the CT scan is complete the Radiation Oncologist, Medical Physicist, and Dosimetrist will use advanced computer software to plan the optimal radiation treatment each patient will receive. Once the simulation and planning phases are completed and quality assurance checks are done, the patient will be called to schedule the daily radiation treatments.