Breast Cancer Radiation Therapy

Dr. Charles Thomas, from OHSU's Knight Cancer Institute, speaking with a female patient
Dr. Charles Thomas is among the expert radiation oncologists at OHSU. We offer you the latest technology and techniques.

The OHSU breast cancer clinic provides the Northwest’s most advanced radiation therapy for breast cancer. We combine team-based care with top technology. Our offerings include:

  • Coordinated care, with your radiation oncologist and other doctors all working together.
  • Doctors who continually research how to provide the best result with the least amount of treatment.
  • A technique to limit radiation to the heart, reducing the risk of long-term side effects.
  • The Northwest’s only Intrabeam therapy for breast cancer, enabling carefully selected patients to receive just one dose of radiation treatment.

Why have radiation therapy?

Radiation therapy is an effective, highly targeted treatment that uses beams of energy to kill cancer cells. Killing any cancer cells left after surgery lowers the risk of cancer coming back. For some patients, radiation can be paired with lumpectomy to avoid a mastectomy.

The most common short-term side effects are fatigue and skin irritation at the site of therapy. If you need radiation therapy, your radiation oncologist will go over which options make the most sense for you.

Types include:

  • Radiation therapy delivered to the breast or lymph nodes from outside the body.
  • Radiation therapy delivered using a probe inside the body.

Our excellence

Doctors work together at the OHSU breast cancer clinic. Your surgeon and radiation oncologist plan procedures as a team, giving you seamless care and access to all appropriate options.

They also participate in research, with a key goal of achieving the best results with the least amount of therapy. One clinical trial seeks to answer whether, for certain patients, a smaller lymph node surgery paired with radiation is as effective as a larger lymph node surgery and radiation.

Protecting your heart

Deep inspiration breath hold, or DIBH, is a technique provided at OHSU to avoid radiation to the heart.

Patients who need radiation therapy to the left breast hold a deep breath for 20 to 30 seconds. This pushes the breast tissue away from the heart, protecting the heart from radiation beams. The patient breathes freely between exposures. Patients receive coaching and support in this technique before radiation therapy is delivered.

Radiation to the heart increases the risk of long-term side effects such as heart disease. DIBH has been found to significantly reduce heart exposure.

A doctor and patient converse during a radiation therapy consultation

Intrabeam therapy

Intrabeam therapy is delivered in one dose, usually during surgery to remove a breast tumor (lumpectomy). For patients who fit detailed criteria, this can avoid weeks of daily treatments.

Intrabeam therapy is a form of intraoperative (during surgery) radiation therapy, or IORT. It’s also called partial breast radiation. Traditional radiation therapy for breast cancer is called whole breast radiation.

The surgical oncologist (cancer surgeon) removes the breast  tumor. The radiation oncologist wheels over the Intrabeam equipment, which includes a robotic arm. The end of the arm is fitted with a sphere-shaped applicator that precisely fits the “tumor bed,” the area where the tumor was removed.

One dose of radiation is delivered. The procedure extends surgery by about 30 to 40 minutes.

After surgery, if the patient’s lymph nodes and margins (the tissue next to the tumor) are found to be cancer-free, she won’t need more radiation therapy. This spares the patient five or six weeks of daily radiation treatments. If cancer cells are found in lymph nodes or margins, the patient will need whole breast radiation therapy, though the schedule is shortened by more than a week.

To get Intrabeam therapy, patients must:

To avoid additional radiation therapy after Intrabeam, patients must have:

  • Negative margins, meaning no cancer is found in tissue next to the tumor.
  • Cancer-free lymph nodes. (Read about lymph nodes on our Understanding Breast Cancer page.)

Pluses: Intrabeam delivers radiation therapy in one dose. This makes it attractive to patients who live far from a hospital or have difficulty driving. It also delivers radiation directly to the affected tissue, lessening the risk of side effects. 

Minuses: Many patients aren’t eligible. Patients also don’t know until a few days after surgery, when margin and lymph node results come back, if they are done with radiation therapy. 

Partial breast radiation versus whole breast radiation: Some radiation oncologists question whether partial breast radiation is as effective as whole breast radiation at lowering the risk of cancer coming back. The American Society for Radiation Oncology concluded that partial breast radiation is effective as long as patients fit detailed guidelines. At OHSU, doctors followed 127 patients who received Intrabeam therapy from 2009 through 2016. They found that it's a safe and effective option for carefully selected patients.

Learn more

For patients

Call 503-494-4673 to:

  • Make an appointment
  • Seek a second opinion
  • Ask questions


Parking is free for patients and their visitors.

Center for Health & Healing Building 2
3485 S. Bond Ave.
Portland, OR 97239
Map and directions

Refer a patient

Read more

Learn more about OHSU Knight Cancer Institute treatments: