Background and purpose: The aim of this study was to compare the need for re-irradiation, rates of pathological fractures, and spinal cord compressions in patients randomised to single-fraction radiotherapy (8 Gy x 1) or multiple-fraction therapy (3 Gy x 10) and with a long-term follow-up. The underlying hypothesis was that single-fraction and multiple-fraction regimens are equally effective.
Material and methods: The present study reports on the Norwegian sub sample of an international large prospective-randomised multicentre study. One hundred and eighty patients with painful skeletal metastases in four Norwegian hospitals were randomised to receive single-fraction (8 Gy x 1) or multiple-fraction (3 Gy x 10) radiotherapy.
Results: Patients in the single-fraction arm received significantly more re-irradiations as compared to the multiple-fraction arm (27% versus 9%, p=0.002). There were no significant differences in the rate of pathological fractures (5% versus 5%, p=1.00) or spinal cord compressions (1% versus 4%, p=0.37) between the two treatment groups.
Conclusion: The present study indicates no difference between radiotherapy with 8 Gy x 1 and 3 Gy x 10 for the majority of patients with painful bone metastases, also in a long-term perspective. Importantly, the patients in this study were followed up until death, and the trial showed no disadvantage for 8 Gy x 1 compared to 3 Gy x 10. Despite the fact that single-fraction treatment will imply an approximately 2.5-fold greater need for re-irradiation, single-fraction treatment is considered more convenient for the patients and more cost-effective for the radiotherapy departments.