Breast Cancer: Intraoperative Radiation Therapy (IORT)

Overview

Intraoperative radiation therapy (IORT) is a specialized form of radiation treatment for breast cancer, delivered during lumpectomy surgery. Unlike traditional radiation, IORT targets the tumor site directly with a single, high dose after the tumor is removed and while the incision is still open. This approach aims to eliminate any remaining cancer cells. However, its availability is limited due to the need for specially shielded operating rooms and complex logistical coordination. 

What Is Breast IORT?

Breast IORT, or Intraoperative Radiation Therapy for breast cancer, is a technique where a concentrated dose of radiation is administered to the breast tissue immediately after a cancerous tumor is surgically removed during a lumpectomy. This direct application of radiation to the tumor bed, while the surgical site is still open, aims to destroy any microscopic cancer cells that might remain, potentially reducing the need for weeks of post-operative external beam radiation. Breast IORT delivers a targeted treatment in a single session, making it a distinct approach in breast cancer therapy.

Advantages of Intraoperative Radiation Therapy (IORT)

You may be a candidate for breast IORT if:

• You were diagnosed with early-stage breast cancer
• Your lymph nodes test negative for cancer cells
• The tumor is small (in one trial, most tumors being treated measured up to 2 cm; in another trial, tumors were up to 2.5 cm)
• You are over age 50

IORT is not generally recommended for women under the age of 50 because long-term post-treatment issues in this group are not yet fully understood.

Breast IORT Procedures

In the event that IORT is recommended for you, you will probably go through the following procedures:

• In the operating room, anesthesia will be administered to you.
• Your surgeon will perform a lumpectomy while you are unconscious, making a breast incision and extracting the tumor.
• After the tumor is removed, your healthcare provider will insert the IORT device’s applicator straight into the “tumor bed,” or the opening where the tumor was.
• The radiation dose will be applied directly to the tumor bed through the applicator. It can take up to thirty minutes for the treatment.
• The applicator will then be removed.
• The incision will then be closed by your surgeon.

After a breast IORT lumpectomy, your healthcare provider will conduct cancer cell detection tests on the surrounding lymph nodes and the tumor margin—the area of tissue surrounding the tumor. If these tests indicate the presence of cancer cells, your provider may recommend EBRT to minimize the risk of recurrence.

Risks and Side Effects of Intraoperative Radiation Therapy (IORT)

Studies have shown that while the risk of the cancer returning in the same breast may be slightly higher with IORT compared to traditional EBRT, the overall survival rates for breast cancer are the same for both treatments. This is an important point to discuss with your doctor to help you decide on the most appropriate treatment for your situation. The primary drawbacks of IORT include potential fluid buildup in breast tissue and temporary bruising.

Breast IORT Results 

The following are benefits provided by breast IORT.

• Daily treatments for an average of six weeks are frequently necessary for traditional radiation therapy. One-time radiation therapy with a single dose is provided via IORT.
• IORT is far less expensive than conventional radiation therapy because it only needs one radiation dosage.
• Less radiation exposure to healthy tissue compared to EBRT. IORT exposes surrounding healthy tissue and organs to less radiation.