Factors predictive of failure to complete planned intraoperative breast radiation using the intrabeam® system.

Purpose: Intraoperative radiation therapy (IORT) is a form of breast irradiation that is delivered in a single session at the time of partial mastectomy. In up to 10% of patients, planned IORT is not completed; this leads to wasted resources and decreased patient satisfaction. Our objective was to evaluate factors associated with failure to complete planned IORT.

Methods And Materials: An IRB-approved review of planned IORT cases from 2011 to 2015 was conducted. Eligibility criteria included: age ≥60, invasive ductal or mammary carcinoma, tumor <3.0 cm, ER positive, and clinically node negative. Discontinuation of planned IORT was at the discretion of the breast surgical and radiation oncologists.

Results: Twenty-one (15%) of one hundred and forty-five planned IORT cases were not completed. Reasons for failure to complete IORT included inadequate applicator to skin distance (n = 15, 71%), altered wire localization findings the day of surgery (n = 4, 19%), equipment failure (n = 1, 5%), and hemodynamic instability (n = 1, 5%). Significant surgeon variability was associated with failure to complete planned IORT (P < 0.001).

Conclusions: Insufficient skin-to-applicator spacing is the most common reason for failure to complete IORT. In this series, higher volume surgeons completed a greater proportion of IORT cases, suggesting a learning curve to patient selection or intraoperative technique. J. Surg. Oncol. 2016;114:930-932. © 2016 Wiley Periodicals, Inc.