Evidence base for hypofractionation in RNI and reconstruction setting.
Authors: Prof Tabassum Wadasadawala
Institution: Tata Memorial Centre
Introduction
The evolution of breast radiotherapy from conventional fractionation to shorter schedules has transformed treatment delivery, improving patient convenience, resource utilisation, and access to care. However, the adoption of hypofractionation in regional nodal irradiation (RNI) and following breast reconstruction has historically been limited by concerns regarding lymphoedema, brachial plexus toxicity, locoregional control, and reconstruction-related complications.
Methods
Recent randomized evidence has substantially strengthened the role of moderate hypofractionation in locoregional radiotherapy. Trials including HypoG-01 and Skagen Trial 1 have evaluated 40 Gy in 15 fractions against conventional fractionation, providing reassuring evidence regarding arm morbidity and treatment outcomes. Evidence from studies incorporating internal mammary node irradiation further supports the feasibility of shorter treatment schedules for comprehensive nodal irradiation.
Results
An important advance is the RT CHARM (Alliance A221505) trial, which directly addresses hypofractionated postmastectomy radiotherapy (PMRT) in patients undergoing breast reconstruction. The comparison of 42.56 Gy in 16 fractions with 50 Gy in 25 fractions provides prospective evidence regarding reconstruction-related complications in implant-based and autologous reconstruction. These findings are particularly relevant when balancing oncological efficacy, reconstructive outcomes, patient-reported quality of life, and treatment burden.
Conclusion
This talk will critically review the evidence supporting hypofractionated RNI and post-reconstruction radiotherapy, examining trial design, oncological outcomes, toxicity profiles, reconstruction-related morbidity, and implications for clinical practice. Particular emphasis will be placed on the applicability of these findings to diverse patient populations and resource-constrained healthcare settings. The evidence gaps surrounding ultra-hypofractionated PMRT, particularly 26 Gy in five fractions in reconstructed patients receiving comprehensive RNI, will also be discussed.