Lag Time Between Evidence and Guidelines: Can Clinical Pathways Bridge the Gap?

The 2018 American Society for Radiation Oncology guidelines state that hypofractionated whole-breast irradiation (HF-WBI) may be used for early-stage breast cancer regardless of age, although evidence to support this became available years ago. Before guideline publication, we sought to change the practice pattern within an integrated, comprehensive radiation oncology network using clinical pathways.

The breast clinical pathway was amended in January 2016 to allow HF-WBI as a pathway-concordant option for women younger than 50 years of age. In December 2016, the pathway was amended to mandate HF-WBI as the only pathway-concordant option. Women younger than 50 years of age treated for stage 0 to IIA breast cancer, without irradiation of regional nodes, were included. Potential predictors of hypofractionation use were analyzed using binary logistic regression.

We identified 305 patients treated between 2013 and 2017. From 2013 to December 2015, HF-WBI use was 4.2%. After the first and second amendments, use increased to 53.1% ( P < .001) and 96.5% ( P < .001), respectively. Before amendment 1, there was no difference in use of hypofractionation at academic (2.6%) versus community (4.7%) sites ( P = .568). After amendment 1, academic practices were more likely to use hypofractionation (72.0% v 44.6%; P = .026). After amendment 2, there was, again, no difference between academic (100.0%) and community (95.3%) practices ( P = .999).

With implementation of a clinical pathway that mandated use of HF-WBI regardless of age, HF-WBI use for women younger than 50 years of age rapidly increased from 4.2% to greater than 95%. Clinical pathways effectively standardize patterns of care to reflect the most up-to-date clinical evidence, independently of guideline publication.