Regional Lymph Node Irradiation for Breast Cancer

Abstract

Over recent years, inverse planned IMRT (intensity modulated radiation therapy) or VMAT (volumetric arc therapy) techniques have been increasingly incorporated into the management of breast cancer patients requiring regional nodal irradiation (RNI). Guidelines for target delineation have been modified based on mature datasets of patterns of regional nodal failure in breast cancer patients (Macdonald et al., RADCOMP Breast Atlas. RTOG Foundation: Radiation Therapy Oncology Group, 2016; DeSelm et al., Int J Radiat Oncol Biol Phys 103:583–591, 2019). One practical advantage of VMAT over IMRT for RNI is its relatively rapid delivery time, which enables its combination with deep-inspiratory breath hold (DIBH) techniques that may subsequently minimize exposure of high doses to the heart and lung in left-sided breast cancers (Dumaine et al., Radiat Oncol 13:187, 2018). Adoption of technologies such as surface-guided radiation therapy have enhanced the accuracy of set-up and treatment delivery. Collectively, these changes have led to dramatic refinement of dose parameters for avoidance organs, as briefly summarized below.