Intra-operative Radiotherapy (IORT) at California Pacific Medical Center

After lumpectomy, there is the possibility that the cancer may return. To lower this risk, external beam radiation therapy after surgery is usually recommended to the breast.

Intra-operative radiation (IORT) therapy allows physicians to deliver a concentrated dose of radiation to the tumor site immediately after removal, helping to eradicate the microscopic tumor cells that may be left behind.

During IORT, a precise radiation dose is directed to the site of the lumpectomy while sparing healthy surrounding tissues. Critical adjacent organs (such as the heart and lungs) can be spared with special shielding.

For a small group of patients, IORT may be the only radiation treatment they need – largely dependent on the patient’s age, tumor size, lymph node status and tumor characteristics. For patients that don’t fit these select criteria, the IORT may still play a role at the time of lumpectomy but these patients will require external radiation therapy after surgery because of the tumor characteristics. For these patients, the length of these treatments will be reduced because of the IORT.

The Treatment

IORT takes place in the operating room under anesthesia after your surgeon removes the tumor. The IORT applicator is placed into the tumor bed by the breast surgeon. Then the radiation oncologist delivers the radiation treatment in the operating room. The entire dose of radiation is delivered on average in 35 minutes. When the treatment is complete, the surgeon removes the IORT applicator and closes the incision. Antibiotics are prescribed to prevent an infection. Follow-up care after IORT is the same as for any lumpectomy.

Potential Side Effects

Early IORT side effects can include redness of the skin over the surgical site, dryness or itchiness. These reactions will go away after a few weeks. A small number of patients can have fluid build-up, bleeding, infection or a delay in wound healing. Late IORT side effects can include thickening of the breast tissue in the treated area, lightening of the skin or slight changes in the appearance of the breast.

If you would like to learn more about IORT, please contact your breast surgeon or radiation oncologist.