Update on Accelerated Whole Breast Irradiation.

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Adjuvant radiation therapy (RT) is standard after breast conserving surgery (BCS).
• Traditionally, whole breast irradiation (WBI) used standard fractionation over 5-7 weeks.
• Newer regimens aim to shorten treatment duration without compromising efficacy.

Purpose of the Study:

• To review the evolution of adjuvant radiation therapy fractionation for early-stage breast cancer post-BCS.
• To compare standard, moderately hypofractionated, and ultra-hypofractionated WBI approaches.
• To discuss future directions in de-intensifying radiation treatment for breast cancer.

Main Methods:

• Review of randomized trials comparing different WBI fractionation schedules.
• Analysis of local control, toxicity, and cosmetic outcomes.
• Examination of emerging ultra-hypofractionated WBI data and its implications.

Main Results:

• Moderately hypofractionated WBI (3-4 weeks) shows comparable local control, toxicity, and cosmetic outcomes to standard WBI (5-7 weeks).
• Ultra-hypofractionated WBI (5 fractions) demonstrates noninferiority to moderately hypofractionated WBI at 5 years.
• These shorter regimens are becoming the standard of care for select patients.

Conclusions:

• Moderately hypofractionated WBI is the current standard for most patients undergoing BCS.
• Ultra-hypofractionated WBI shows promise for further treatment shortening.
• Shorter RT regimens may enable de-intensification strategies, potentially omitting endocrine therapy in some cases.