Changes in brachytherapy-based APBI patient selection immediately before and after publication of the ASTRO consensus statement.

Abstract

In July 2009, American Society of Radiation Oncology (ASTRO) released a consensus statement (CS) to guide patient selection for accelerated partial breast irradiation (APBI). The goal of this study was to examine how practice patterns changed following the guideline's release. The Surveillance, Epidemiology, and End Results database was queried from 2008 to 2010 for females aged ≥20 years receiving breast conservation via brachytherapy. Among the APBI cohort, characteristics and CS grouping ("suitable," "cautionary," or "unsuitable") of patients receiving APBI in the 18 months before (January 2008 to June 2009) and after (July 2009 to December 2010) guideline publication were analyzed. A total of 87,528 patients undergoing breast conservation therapy were identified. Of this, 4,253 patients (4.9%) received brachytherapy-based APBI. Limiting the analysis to patients not missing data that would affect their CS classification rendered 3,828 patients. The proportion of breast conservation patients receiving brachytherapy-based APBI before and after CS release remained the same (4.9% vs. 4.8%, p = 0.36). Among patients receiving brachytherapy-based APBI, the unsuitable category decreased (15.8 vs. 11.1%, p < 0.01), whereas the suitable category increased (37.7% vs. 42.1%, p = 0.03), and the cautionary category was stable (46.5% vs. 46.7% p = 0.90) after guideline publication. Joinpoint regression analysis failed to reveal that the changes in practice patterns corresponded with the CS publication date. The period before and after publication of the ASTRO CS was associated with a decrease in "unsuitable" patients and an increase in "suitable" patients being treated with brachytherapy-based APBI. This trend began before guideline release and thus cannot be definitively attributed to the ASTRO CS.