The Association Between Use of Hypofractionation and Treatment Completion Among Recipients of Radiation Therapy Post-Mastectomy

Abstract

Purpose: Although there is some evidence to support the use of hypofractionated (HF) radiation therapy (RT) postmastectomy, it is not currently the standard of care. RT noncompletion and delayed completion have been shown to lead to inferior outcomes. This study assesses the association between the choice of an HF versus conventionally fractionated regimen and completion.

Methods and materials: RT orders placed in 2016 and 2017 for patients with a national health plan, along with the associated claims, were extracted. Each order was assigned a target date for timely completion, as well as a date 30 days after the target, which was used to assess delayed completion. Univariate analyses and logistic regressions were conducted to test for an association between regimen and completion. A Poisson regression was used to examine the association between regimen and length of treatment delay among patients completing RT.

Results: Of the 743 orders meeting inclusion criteria, 56 (7.5%) were for HF. Unadjusted analyses found that the timely and delayed completion rates were significantly (P < .001) higher for patients receiving HF. The adjusted odds ratios (HF order versus CF order) were 3.96 (95% confidence interval, 2.23-7.01) for timely completion and 2.64 (95% confidence interval, 1.43-5.15) for completion within 30 days of the target. Among completers, an order for HF was significantly (P < .001) associated with less delay.

Conclusions: When an HF regimen was ordered, patients were more likely to complete therapy without a delay, to complete therapy overall, and, if experiencing a delay, to experience a shorter delay.