Intraoperative radiation therapy (IORT) is an intensive radiation treatment that delivers a concentrated beam of radiation to tumors as they are located during surgery. IORT allows direct radiation to the tumor while sparing normal surrounding tissue. The type of IORT most commonly used at Mayo Clinic is also called intraoperative electron radiation therapy, or IOERT.
Thousands of people have received IORT treatment at Mayo Clinic. The IORT team at Mayo Clinic includes specialists in radiation oncology who perform the procedure, surgery,anesthesiology and pathology. In Arizona, Mayo Clinic is one of only a few institutions in the United States that uses a Mobetron, a mobile device that can provide radiation therapy in the operating room.
Conditions treated with IORT
IORT is used for cancer that cannot be cured with surgery alone and for tumors that are either attached or close to vital tissues. Recurrent rectal cancer is the most common condition treated with IORT at Mayo Clinic. IORT is also used to treat:
- Cervical, uterine and ovarian cancers
- Prostate, bladder and kidney cancers
- Stomach, pancreatic, colon, rectal and anal cancers
- Soft tissue sarcoma
For people who have recurring cancer and people who have locally advanced cancers, IORT can be an effective therapy in achieving long-term tumor control.
How it works
IORT is almost always used along with external radiation prior to surgery. During surgery, after the surgeon removes as much of the tumor as possible, a machine called a linear accelerator delivers a concentrated beam of electron radiation directly to the tumors. The surgeon moves healthy organs out of the radiation field to prevent damage, and special tubes are used to focus the beams safely on the tumor(s).
IORT also may be used when the remaining tumor is too small to see.
Advantages of IORT
IORT allows doctors to administer high doses of radiation to tumors without exposing nearby healthy organs to radiation. A single dose of intraoperative radiation may have as much effect on the tumor as 10 to 20 daily radiation treatments. IORT offers the following benefits:
- Higher radiation dosage to cancer cells
- Faster radiation delivery during surgery
- Decreased radiation exposure to normal surrounding tissue
- Safer application compared with traditional radiation treatments
Like other treatments, IORT carries some risks. Mayo Clinic doctors discuss the benefits and risks with people to help them decide on a treatment.