Dose constraints in breast cancer radiotherapy. A critical review

: Radiotherapy plays an essential role in the treatment of breast cancer (BC). Recent advances in treatment technology and radiobiological knowledge have a major impact in BC patients with locoregional disease as the majority are now long-term survivors. Over the last three decades, intensity-modulated radiotherapy (IMRT), volumetric-modulated arc therapy (VMAT) and deep inspiration breath-hold (DIBH) techniques, together with the increasing adoption of moderately hypofractionated and ultra-hypofractionated treatment schedules as well as the possibility to offer partial breast radiotherapy to a well-defined patient subset have significantly changed radiotherapy for BC patients. As dose-volume constraints (DVCs) have to be adapted to these new treatment paradigms we have reviewed available evidence-based data concerning dose-constraints for the main organs at risk (OARs) that apply to the treatment of whole breast/chest wall radiotherapy, whole breast/chest wall radiotherapy including regional nodal irradiation (RNI) and partial breast irradiation (PBI), for the most relevant fractionation schedules that have been introduced recently. This narrative review provides a comprehensive summary that may help to harmonize treatment planning strategies.

Radiotherapy plays an essential role in the treatment of breast cancer (BC). Recent advances in treatment technology and radiobiological knowledge have a major impact in BC patients with locoregional disease as the majority are now long-term survivors. Over the last three decades, intensity-modulated radiotherapy (IMRT), volumetric-modulated arc therapy (VMAT) and deep inspiration breath-hold (DIBH) techniques, together with the increasing adoption of moderately hypofractionated and ultra-hypofractionated treatment schedules as well as the possibility to offer partial breast radiotherapy to a well-defined patient subset have significantly changed radiotherapy for BC patients. As dose-volume constraints (DVCs) have to be adapted to these new treatment paradigms we have reviewed available evidence-based data concerning dose-constraints for the main organs at risk (OARs) that apply to the treatment of whole breast/chest wall radiotherapy, whole breast/chest wall radiotherapy including reg...