Sep 28

SS 07 - Breast Cancer 1: Redefining Radiation Schedules: Hypofractionation and APBI Across the Breast Cancer Spectrum

141 - Preliminary Results of Hypofractionated Regional Nodal Radiation in Breast Cancer (HARVEST): A Randomized Non-Inferior Multi-Center Phase III Trial

04:55pm - 05:05pm PT

Room 301-304

Presenter(s)

Fei-Fei Xu, MD - Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, Shanghai

F. F. Xu, L. Cao, and J. Y. Chen; Shanghai Key Laboratory of Proton Therapy, Shanghai, China

Purpose/Objective(s):

To report the acute toxicity and quality assurance of the HARVEST study which was to investigate whether hypofractionated radiotherapy (HF-RT) with regional nodal irradiation (RNI, including internal mammary nodes (IMN)) is non-inferior to conventional fractionated radiotherapy (CF-RT) for breast cancer.

Materials/Methods:

Breast cancer patients after breast surgery were randomized into the HF-RT group (40.05Gy/15Fx) or CF-RT group (50Gy/25Fx). Acute toxicity was assessed with the Common Terminology Criteria for Adverse Events (CTCAE) V.3.0 scale. Cosmetic outcome was assessed using the Harvard scale. Target coverage and dose of organs at risk (OARs) were evaluated for dosimetry analysis.

Results:

A total of 801 patients were enrolled with 400 in HF-RT group and 401 in CF-RT group. There were 48.8% of patients with left breast cancer, 80.4% with pT1-2 tumors and 45.7% with pN1. There were no significant differences in clinical pathological factors between two groups.

The rate of patients experienced any grade =2 toxicity showed no significant difference between the two groups (p=0.34). Dermatitis was the most common acute toxicity with a significantly higher incidence in the CF-RT group than the HF-RT group (grade=2: 6.7% vs. 3.3%, p=0.01). There were no significant differences in the incidence of other acute toxicities including radiation-induced fatigue, radiation pneumonitis, breast pain, dysphagia and breast edema between the two groups. The proportion of good or excellent cosmesis outcome was also no significant difference between two groups. Protocol compliances were above 90% in two groups with no significant difference in most of dosimetry parameter for targets and OARs constraints.

Conclusion:

This early analysis demonstrated that HF-RT with RNI is feasible and associated with comparable acute toxicities, acceptable cosmesis and better dosimetry results compared with CF-RT. Additional follow-up is needed to assess the long-term safety and efficacy.