What Is Intraoperative Radiotherapy (IORT)?

What Is Intraoperative Radiotherapy (IORT)?

Intraoperative Radiotherapy (IORT) is a technique that delivers a concentrated dose of radiation directly to the tumour bed or surgical cavity during an operation, immediately after tumour removal. It allows high-precision irradiation of the highest-risk area while minimising dose to surrounding healthy tissues.

How Does IORT Work?

After tumour resection, the radiation oncologist and surgeon identify the area at highest risk for local recurrence (the tumour bed, involved margins or lymph node regions). The radiation applicator is placed directly in contact with this tissue. A single high dose of radiation (typically 10–20 Gy) is delivered over minutes. Surrounding sensitive structures (bowel, vessels, nerves) can be displaced or shielded. The wound is then closed and recovery proceeds normally.

Main Applications

Retroperitoneal sarcomas: IORT to the posterior tumour bed where complete resection is impossible due to adjacent vascular structures. Rectal cancer: For locally advanced or recurrent rectal cancer where surgical margins are close or involved. Breast cancer: Intraoperative partial breast irradiation as an alternative to whole-breast external beam radiotherapy in selected early-stage cases. Pancreatic cancer: Adjuvant IORT to the tumour bed. Head and neck recurrences.

Advantages of IORT

Precise targeting of the highest-risk area. Single-fraction delivery eliminates the need for weeks of external beam radiotherapy. Healthy tissues can be physically displaced during irradiation. Biological dose equivalent exceeds that of fractionated external beam. Complementary to adjuvant external beam radiotherapy when combined.