IORT as a Boost Treatment

What is a Boost Treatment?

Conventional radiotherapy after breast conserving surgery consists of a prescribed dose of external beam radiation therapy (EBRT) to the whole breast and a supplemental dose of radiation called a boost. This supplemental radiation dose is typically delivered over a 5-10 day period at the end of WBRT. During the boost portion of therapy, a higher daily dose of radiation is given to ensure that any remnant cancer tissue is eradicated. This radiation dose is delivered, while avoiding an increase in toxicity. This treatment is accomplished by focusing the beam of radiation on the area of the tumor cavity, thus lessening radiation delivered to the whole breast.

Today, an external beam boost following a lumpectomy and whole breast external beam radiation therapy (WBRT) is the recommended treatment option for patients undergoing breast conservation therapy.

IORT delivered as a Boost

Intraoperative radiotherapy or IORT provides an accurate localized method of treating the tumor bed with radiation, while minimizing healthy tissue exposure to radiation. When IORT is used to deliver a boost, radiation is delivered at the time of surgery as a single dose prior to the start of external beam radiation therapy. Giving an intraoperative boost at the time of surgery can reduce the subsequent amount of external radiation required.