Introduction: During the COVID-19 pandemic, Lombardy (Northern Italy) Regional Health Council created hubs for cancer care, meant to be SARS-CoV-2-free pathways for cancer patients. The workflow of breast cancer (BC) radiotherapy (RT) in one of the hubs is presented here. Methods: Candidates to adjuvant RT during the pandemic peak of March-April 2020 were compared to those treated in the same period of 2019, and patient volume, deferral rate, and type of RT were analyzed. Statistics were calculated with χ 2 or Fisher exact tests for categorical variables, and the Wilcoxon rank test for continuous variables. Results: In March-April 2020 the BC patient volume increased by 28% compared to the same period in 2019 (scheduled patients: 175 vs. 137) and amid travel restrictions it was kept high (treated patients: 136 vs. 133), mainly due to an influx from across Lombardy. RT schemes basically did not change, being already centered on hypofractionation. The increase of median time (67 vs. 74.5 days in 2019 and 2020, respectively) to the commencement of RT for low-risk patients was clinically negligible yet statistically significant (p = 0.03), and in line with the pertinent recommendations. No significant difference was found in the time interval between treatments and RT for high-risk patients. Concomitant chemoradiotherapy was avoided throughout the pandemic peak. Twenty-one women (13.6%) delayed either computed tomography simulation or RT commencement mainly because of COVID-19-related concerns and mobility restrictions. Conclusion: The workload for BC was high during the pandemic peak. Hubs allowed the continuation of oncologic treatments, while mitigating the strain on frontline COVID-19 hospitals.