Instruments for determining clinically relevant fatigue in breast cancer patients during radiotherapy

Background This study aimed to determine radiotherapy (RT)-related changes in cancer-related fatigue (CRF), using Multidimensional Fatigue Inventory-20 (MFI-20), and fatigue-intensity rating (FIR) instruments at three different timepoints and to identify the optimal thresholds of MFI-20 scores which would correlate with moderate-to-severe fatigue warranting an intervention in breast cancer patients treated with RT.