Radiation therapy is a very common type of treatment for many types of cancer. Radiation therapy uses high-energy X-rays, gamma rays, electron beams, or protons to kill or damage abnormal cancer cells and shrink cancer tumors. Radiation therapy is sometimes called radiotherapy, irradiation or X-ray therapy. Radiation therapy has been used since the early 1900s to treat cancer. In some cases, it’s is used alone to kill cancer cells. However, radiation therapy is most commonly used along with surgery and/or chemotherapy.

The decision to include radiation therapy in your treatment plan was made based on many unique factors, including the size and type of your tumor, genetic, health history, and personal health goals.

There are several forms of radiation that can be administered non-invasively from outside of the body, similar to an X-ray, and other forms that are administered internally through implants.

Radiation Therapy


How does radiation therapy work?

During radiation therapy, cancer doctors who specialize in this form of treatment — called radiation oncologists — will plan and oversee your radiation therapy treatment. During each radiation therapy session, your radiation oncologist or a radiation therapist will expose the cancer cells to high-energy radiation using specialized external equipment or by implanting radioactive material at the site of the cancer. The exposure causes the DNA in cancer cells to fracture. Once the DNA is fractured, the cells have a difficult time growing. The cells will either continue to grow very slowly or they will stop growing completely and die off.

Surrounding healthy cells will be exposed to some radiation, too, but most of them will recover and continue to function properly whereas cancer cells will not. Rocky Mountain Cancer Centers uses the most advanced and latest radiation technology that helps minimize the exposure or effect on healthy cells. Every piece of technology used at Rocky Mountain Cancer Centers is accredited and checked daily to ensure the highest level of pinpoint accuracy.

What are the different types of radiation therapy?

There are two main types of radiation therapy: external beam radiation therapy and internal radiation therapy.

External Beam Radiation

External beam radiation therapy is delivered via a machine from outside the body using a beam directed at the site of the cancer. The equipment does not make physical contact with the body and it can be moved around the body to deliver radiation beams from different angles. Treatment is typically administered five days a week for a period of one to 10 weeks.

External beam radiation therapy technology used at Rocky Mountain Cancer Centers includes:

  • TrueBeam Radiotherapy, we are able to offer some of the most advanced radiation therapy treatments available today. This exciting technology opens new treatment options, allowing us to better tailor treatments that match your anatomy and your specific cancer. Learn more about TrueBeam.
  • Image-guided radiation therapy (IGRT), which uses imaging such as computed tomography (CT), ultrasound, or X-rays to consistently and accurately direct external radiation dose.
  • Intensity-modulated radiation therapy (IMRT), a type of external beam radiation that uses multiple beams to precisely shape the high doses of radiation around the tumor and attempt to avoid giving high doses to surrounding critical organs that can’t tolerate these high doses. Learn more about IMRT radiation therapy.
  • Stereotactic radiosurgery (SRS) uses advanced Novalix Tx linear accelerators that perform similar to Cyberknife and Gamma Knife, but allow treatment of larger more irregularly shaped tumors. It was designed specifically to treat brain tumors.
  • Stereotactic Body Radiation Therapy (SBRT) uses a technique similar to stereotactic radiosurgery (SRS) to treat tumors outside the skull, like lung and liver.

For breast cancer treatment, hypofractionated radiation therapy may be available. Your cancer care team will decide if it's suitable for you. This is because the expected results vary based on your unique factors. 

Internal Radiation Therapy

Internal radiation therapy involves implanting radioactive material in the body near or inside the tumor. Different types of brachytherapy implants include pellets, seeds, ribbons, wires, needles, capsules, balloons, or tubes. The implant is placed using catheters, small tubes inserted through veins or arteries without surgery. Depending on the type of material used, it may be left in for a few minutes, a few days, or permanently.

At Rocky Mountain Cancer Centers, we offer two forms of internal radiation therapy:

  • High-dose rate, or HDR, brachytherapy is frequently used in the treatment of uterine or cervical cancers and is now being used for some forms of skin cancer. When using HDR brachytherapy, our board-certified radiation oncologists place the radioactive material inside the body for just a few minutes at a time. The radioactive material is removed before the patient goes home. Treatment is usually repeated three to five times with about a week between each session. Learn more about HDR brachytherapy. 
  •  Selective internal radiation therapy (SIRT) is an image-guided, non-surgical procedure used to treat tumors in the liver. Our board-certified radiation oncologists work alongside an interventional radiologist to deliver tiny radioactive beads into the blood vessels that lead directly to the tumor. The radioactive material destroys the blood vessels leading to the tumor, which reduces or stops growth of most liver tumors.

Radiation Therapy Videos

Learn more about what to expect, tips, and facts about radiation therapy. 

How does my doctor determine if radiation therapy is right for me?

When you received your cancer diagnosis, you most likely were referred next to a cancer surgeon or a cancer specialist called a medical oncologist.  At that point, a treatment plan including radiation therapy was developed was based on many factors, including:

  • Type and grade of cancer
  • Size and location of the tumor
  • Sensitivity of surrounding tissue
  • Genetic components
  • Family history
  • Your age, overall health and medical history
  • Your treatment goals and preferences

Another factor that may affect your radiation therapy treatment plan is whether you have received radiation to that body part in the past. Each area of the body has a safe lifetime dose of radiation it can receive. The decision to use radiation for recurrence will depend on the location of your tumor, the type of cancer, and the amount of radiation previously used.

Radiation therapy may be recommended alone or it may be recommended before, during, or after other treatments, such as surgery, chemotherapy, or immunotherapy. Once you have been referred for treatment, either from within Rocky Mountain Cancer Centers or from a community provider, we usually can schedule you for your first appointment within two days.

Choosing Rocky Mountain Cancer Centers for Radiation

Radiation therapy is a specialty that requires a high level of skill, precision, and experience. You also want to make sure your provider utilizes state-of-the-art technology and has strict protocols in place to ensure on an ongoing basis that all equipment is properly functioning and precisely calibrated daily so that the high-energy radiation is delivered with pinpoint accuracy.

At Rocky Mountain Cancer Centers, we have been delivering the highest quality of radiation therapy treatment to patients throughout Colorado for more than 20 years. All of our radiation oncologists are board-certified, which means that you will be treated by highly trained and experienced physicians — not doctors who have just completed their training or who are still in residency. In addition, our entire radiation therapy staff from dosimetrists and radiation technicians to nurses and financial counselors work only in radiation therapy and all hold certifications where available.

Other factors to consider include:

  • Technology: Radiation therapy relies heavily on equipment, so be sure to select a center with the most advanced technology.
  • Experience: When it comes to choosing a provider, experience counts. At Rocky Mountain Cancer Centers, we have been treating patients since 1992.
  • Timeliness: Once referred, we try to accommodate all new patients in for their first visit within 24 to 48 hours.
  • Affordability: Rocky Mountain Cancer Centers is the largest community-based cancer network with clinics throughout Colorado. This allows us to offer our services more cost-effectively.
  • Insurance: Be sure to check that the facility accepts your insurance and specific plan. Rocky Mountain Cancer Centers provides Patient Financial Counselors who specialize in radiation therapy to work one-on-one with you to understand what your insurance plan will cover, what you will be responsible to pay, and what financial aid is available.
  • Innovation: While most changes in radiation therapy occur through the technology, researchers are always exploring techniques to better deliver radiation therapy. As part of the US Oncology Research network, the clinical teams at Rocky Mountain Cancer Centers stay up to date on the latest developments, ensuring that you will receive the best care supported by medical evidence.