Factors Associated with Patient-Reported and Physician-Assessed Acute Toxicity after Hypofractionated Breast Radiotherapy, a Report from a Large Multi-Center Cohort Study

Document Type

Conference Proceeding

Publication Date


Publication Title

Int J Radiat Oncol Biol Phys


Purpose/Objective(s): In 2018 ASTRO published an update to the 2011 evidence-based guideline for the use of hypofractionated whole breast irradiation (HF-WBI), increasing the patient populations for whom expert consensus supports the use of HF-WBI. While individualized decision making is encouraged, this updated guideline has been expanded to support HF-WBI for patients <50 years, receipt of chemotherapy, larger separation distance, and a diagnosis of DCIS. For some of these indications, however, only moderate data exist. Thus, we now assess patient and physician reported toxicity data in a large prospective registry for populations not well represented on the trials and in whom there is less experience with this approach. Materials/Methods: Prospective data were evaluated from 2,083 patients receiving HF-WBI plus boost, treated between 1/1/2016 – 8/31/2018 at 24 academic and community centers participating in a statewide consortium. A composite toxicity endpoint was defined as occurrence of self-reported (4-10 modified brief pain inventory) or physician-assessed moderate or severe breast pain (CTCAE v. 4.0 grade 2-3) when patient report absent, and/or physician-assessed presence of moist desquamation. Logistic regression models were constructed isolating the effect of specific criteria from the 2011 HF-WBI guidelines, specifically age <50 years, separation distance >25cm, chemotherapy use, and DCIS. This was further adjusted for patient BMI, breast volume, race, comorbidity, smoking status, and IMRT. Results: Mean age was 62 years, mean separation was 22cm. Twenty-two percent of patients were treated for DCIS with the remaining 78% treated for invasive cancer; 17% of patients received chemotherapy. Of the 2,083 patients, 376 patients had more than one 2011 guideline discordance (for ex. <50 years with chemotherapy), therefore 1707 patients were included in this analysis. On multivariable analysis, patients age < 50 years were estimated to be 82% more likely to experience toxicity than older patients (OR=1.82, 95% CI: 1.11-2.97, p=0.02). While unadjusted difference on univariate analysis showed increased toxicity with separation > 25 cm, multivariable analysis revealed no significant difference in toxicity for separation > 25 cm(p=0.25), DCIS (p=0.6753), or treatment following chemotherapy p=0.10). Conclusion: Young breast cancer patients may be at increased risk of acute toxicity compared with other patients when receiving HF-WBI. Additional work is needed to determine why patients <50 years, who were notably underrepresented in the prospective trials establishing the safety and efficacy of HF-WBI, may experience increased breast pain and dermatitis. Work is underway in our group to determine if this same increased risk is appreciated for patients <50 years receiving conventionally fractionated radiotherapy.





First Page


Last Page


This document is currently not available here.