Efficacy of Intraoperative Radiation Therapy

Intraoperative radiation therapy (IORT) involves delivering radiation during surgery either directly to the tumour or to the site of a previously resected tumour. It is often administered in a single dose. It may also be preceded or followed by external beam radiation therapy (EBRT), administered in several fractions over a number of days or weeks, most often from three to seven weeks.

The Direction québécoise de cancérologie (DQC) asked to INESSS to review the state of the evidence on IORT applied to breast, rectal and brain cancers because it wanted an update on the clinical usefulness  of this technology before considering its potential deployment in Québec’s health system. The DQC

Breast cancer

The available evidence leads to the conclusion that IORT should not become common practice in the current conditions unless rigorously monitored under institutional protocols, coupled with well-built follow-up registries. But, the outcomes of two large-scale randomized controlled trials using two different sources of radiation revealed the potential clinical effectiveness and safety of IORT as an adjuvant treatment after lumpectomy in patients with early-stage cancer.

Rectal cancer

The efficacy of IORT for rectal cancer has not been convincingly proven.

Brain cancer

The observation drawn from the still recent explorations in the update or search for the optimal conditions for using IORT systems applied to the brain confirms the need to conduct phase III trials, some of which are in the planning stages or ongoing.