Comparative evaluation of two hypofractionated radiotherapy regimens for painful bone metastases

In 75% of the patients with bone metastases (BM) pain is the dominant symptom. Radiotherapy (XRT) plays a major role in the palliation of pain in patients with BM. Several schedules of short and long fractionation XRT are used in clinical practice, with hypofractionated treatments being even more attractive for practical reasons. A considerable body of evidence supports the clinical use of short schedules and single-dose XRT. We retrospectively evaluated the efficacy of two short fractionated schedules of 8 Gy as a single dose and 20 Gy in 5 fractions in relieving pain in patients with multiple uncomplicated BM.

From January to December 2001, 130 patients with 146 painful BM were treated with palliative localized XRT. There were 42 males and 88 females with a median age of 58 years (range 28-84). The commonest sites of treatment were the spine (59.6%) and pelvis (14.4%). The primary endpoint was clinically significant pain relief in the first six months of follow-up evaluated with the IAEA (International Atomic Energy Agency) pain measurement score measuring pain severity and pain frequency. Analgesic use was also recorded before and after treatment as drug frequency and drug severity. Patients with painful BM from any primary tumor site were irradiated. Treatment schedules consisted of a course of XRT with 4 Gy/fraction/day (total dose: 20 Gy/5 fractions) (group A, 59 lesions) or with a single dose of 8 Gy (group B, 87 lesions).

There was no significant difference in complete response (CR) rates between treatment schedules: complete pain relief was achieved in 17/59 lesions (29%) in the fractionated group and in 29/87 lesions (33%) in the single-dose group. Also the overall response (complete + partial) was similar: 35/59 lesions (60%) in group A and 60/87 (69%) in group B. The minimum, maximum and median follow-up was 3, 23, and 9 months, respectively, for group A and 3, 20, and 11 months for group B. The actuarial median duration of pain relief was similar: 4.5 months in group A and 4 months in group B. No particular side effects were recorded in either group.

There were no differences between the two fractionation schedules used in our study with regard to pain relief and use of analgesics. Palliation of pain was obtained in approximately two thirds of patients with both schedules, providing further evidence of the similar efficacy between single and multiple fractions. With regard to pain response these data justify a recommendation for the use of a more simple and convenient 8 Gy single fraction for the palliation of uncomplicated BM.