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Updated: Jul 25, 2026
Stereotactic Radiosurgery for Gynecologic Cancer
Published on: April 17, 2012
Clinical Outcomes and Institutional Experience of Ultrahypofractionated Radiation Therapy in Patients With Breast
Hiba Othman1,2, Aisling Barry1,2, Anthony Fyles1,2
1Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada.
Purpose:
Prompted by COVID-19 and publication of the FAST-Forward study, our institution rapidly implemented ultrahypofractionated radiation therapy (U-HFRT) for patients with early-stage breast cancer. Our objective was to evaluate our early experience and toxicity outcomes for U-HFRT.
Methods And Materials:
Patients with consecutive stage 0-II breast cancer treated with adjuvant whole breast radiation therapy (RT) were evaluated. Patient demographics and treatment characteristics were extracted and categorized into 2 cohorts: U-HFRT, 26 Gy/5 fractions (F) and M (moderate)-HFRT, 40.05 Gy/15F. Physician-assessed skin toxicity was evaluated using the Radiation Therapy Oncology Group radiation morbidity scale at baseline/during RT, 1 to 90 days post-RT and >90 days post-RT. Descriptive statistics summarized patient demographics and treatment characteristics and were stratified based on dose fractionation. A multivariable logistic model evaluated associations between toxicity and fractionation.
Results:
Between May 2020 and March 2021, 320 patients were evaluated: 133 (41.6%) received U-HFRT and 187 (58.4%) received M-HFRT. For the U-HFRT cohort, median age at diagnosis was 65.4 years (range, 57-73), 71% had hormone receptor-positive invasive disease, and 18% had ductal carcinoma in-situ. All patients received whole breast RT, and 33% received a boost. U-HFRT was used more in patients who were older, hormone receptor-positive, and did not receive a boost (P < .001). On multivariable analysis, M-HFRT patients experienced significantly more grade 1+skin toxicity during RT (odds ratio = 32.3, P < .001), while 1 to 90 days post-RT, M-HFRT patients experienced less grade 1+ toxicity (odds ratio = 0.36, P < .014) after adjusting for boost, age, and chemotherapy. Rates of skin toxicity >90 days post-RT were low overall.
Conclusions:
This study reports real-world clinical outcomes of patients with stage 0-II breast cancer treated with U-HFRT. We observed low rates of acute skin toxicity compared to M-HFRT, confirming its acceptability as a standard regimen for select patients. Longer term follow-up would be necessary to confirm clinical outcomes in terms of both local control and late normal tissue toxicity.
