What Is Radiation Therapy?

Northwest Montana Radiation Oncology
Radiation therapy, sometimes called radiotherapy, is the use of various forms of radiation to safely and effectively treat cancer and other diseases. Doctors use radiation therapy to try to cure cancer, to control the growth of the cancer or to relieve symptoms such as pain.

Radiation therapy works by damaging the DNA within cancer cells and destroying the ability of the cancer cells to reproduce. When these damaged cells die, the body naturally eliminates them. Normal cells also are affected by radiation, but they are able to repair themselves in a way that cancer cells cannot.

While you undergo radiation therapy, a team of highly trained medical professionals will be working together to make sure you receive the best care possible. A radiation oncologist, a doctor who specializes in using radiation to treat cancer, leads this team.

Patients at Northwest Montana Radiation Oncology often receive other treatments such as chemotherapy, hormone therapy or surgery as well as radiation therapy. To ensure the best possible outcome, this team approach requires collaboration and coordination among all the specialists on a patient's treatment team. During your first visit you will meet with your radiation oncologist, who may consult with other specialists as necessary before your treatment begins to determine the best course of action.


Once you have been referred to Logan Health Radiation Oncology, you will meet with the radiation oncologist for an initial consultation. Typically this appointment takes one to two hours, depending on the nature and complexity of the cancer diagnosis.

During this office visit, the doctor will evaluate your medical history, surgical history, current medications, drug allergies and lifestyle. The nurse will obtain baseline vital statistics, including weight and blood pressure. Your radiation oncologist will review your medical records, including diagnostic imaging such as CT or MRI, as well as current laboratory results. The doctor will discuss the benefits and risks of radiation treatment and answer any questions you might have.

At the end of your consultation, the doctor may schedule additional diagnostic imaging or other tests needed to fully evaluate the disease and prepare for treatment planning.

Simulation and Treatment Planning

The next step in preparing to treat cancer is to schedule a simulation, or treatment planning session. This procedure usually takes place a few days to a few weeks after your first visit with the doctor and after the decision to initiate radiation treatment. Typically simulation is completed in less than an hour, in a single session.

During simulation, the radiation therapist, under the guidance of the radiation oncologist, will place you in position on the CT simulator. Anatomy images are captured for the sole purpose of designing a treatment plan specific to each patient’s cancer. Sometimes the radiation therapist will use devices or molds to manipulate the position of your body on the table to get the best images. Some devices will immobilize parts of your body so that treatment is given precisely in the same location.

After simulation, the radiation oncologist, with the help of the dosimetrist, will use sophisticated treatment planning technology to design the best possible course of treatment. Once the planning is complete, the doctor will approve a treatment plan and write a prescription that serves as an outline of treatment. A week or two after the simulation, a start date and time for a first radiation treatment will be determined.


Radiation therapy uses radiation to kill or damage cancer cells, essentially preventing them from growing and multiplying. It is a tested and effective treatment for many types of cancer. Treatment involves the controlled application of radiation to cancers anywhere in the body. Then the body’s normal healthy tissues and cells are able to recover from exposure to radiation.

The radiation oncology team customizes a treatment plan to meet each patient’s specific needs. Treatment is prescribed and delivered based on many different factors such as:
  • Size and location of the cancer
  • Type of cancer, and whether it has spread or metastasized to other parts of the body
  • Goal of treatment, such as palliative symptom relief or cure of cancer 
Each radiation treatment is like having an X-ray or CT scan; it is painless and generally well-tolerated by most people. Most radiation treatments are done in the outpatient setting and are noninvasive procedures typically lasting 15 to 20 minutes. Most patients experience none or very few side effects so they are able to continue with their normal daily activities while they are undergoing treatment.

External beam radiation therapy will not make patients radioactive, meaning these patients are safe to be around other people, including pregnant women.

Follow-Up Care

After you have completed radiation therapy, your doctor will talk with you about cancer surveillance. Most patients return to the radiation oncologist for regular follow-up visits. Others are referred back to their original doctor, to a surgeon or to a medical oncologist (a doctor who is trained to give chemotherapy, or treatment with anticancer drugs). Your oncology team will track your progress, manage any side effects and monitor your overall health.

Your follow-up care plan may include regular physical examinations and/or medical tests to monitor your recovery. This plan is usually based on medical guidelines for a specific diagnosis. Your doctor will also consider your individual needs and preferences.