Hypofractionated whole and partial breast irradiation: Brazilian Society of Radiotherapy (SBRT) consensus.

Background: Breast cancer is the most common cancer in women worldwide, with 73,610 new cases expected annually in Brazil between 2023 and 2025. Post-operative radiation therapy (PORT) is a critical component of treatment, and recent advances have allowed for shorter treatment times that can help overcome shortages in low- and middle-income countries. The Brazilian Society of Radiotherapy (SBRT) updated its consensus on hypofractionated whole-breast radiotherapy and included recommendations for partial breast irradiation. Materials and methods: The SBRT convened a national panel of experts to develop updated recommendations. Using a modified Delphi method, the panel reached a consensus through structured rounds of voting. Recommendations were categorized based on the strength of available evidence. Results: The consensus supports hypofractionation, which offers shorter, cost-effective treatment schedules, and partial breast irradiation (PBI), which targets high-risk areas while sparing healthy tissue. Despite high-quality evidence, adopting these techniques has been inconsistent. The panel's recommendations provide evidence-based guidance to clinicians, tailored to the Brazilian context, emphasizing safety and efficacy. Conclusion: The updated SBRT consensus presents hypofractionation and PBI as practical alternatives to conventional radiation therapy, offering improved access and reduced costs. These recommendations aim to guide clinicians in adopting these approaches and help address barriers to access.