Dimensions of fatigue during radiotherapy - An application of the multidimensional fatigue inventory

The aim of the present study was to describe fatigue in a Cr group of irrad iated cancer patients. Fatigue was assessed prospectively in 81 Swedish can cer patients, using the Multidimensional Fatigue Inventory (MFI-20), which was also validated in the study, the Karolinska Sleepiness Scale and a Borg CR10 scale before curative radiotherapy, at the end of therapy and 1 and 3 months after treatment. The mean age of these patients was 56 years; 90% w ere female; and 65% were being treated for cancer of the breast. The absorb ed radiation dose was 50 Gy or lower in 90% of the patients. A clear peak i n experienced fatigue according to the three scales was seen at the end of treatment. In the MFI-20 the dimensions of General fatigue, Physical fatigu e and Reduced activity, were more pronounced than the aspects of Mental fat igue and Reduced motivation. Comparison with other studies using the same i nstrument in other irradiated patients revealed a similar pattern. The inte rnal consistency of the Swedish version of the MFI-20 was good. The MFI-20 is shown to be a valid instrument for assessing fatigue in patients undergo ing radiotherapy.