External beam radiotherapy for painful bone metastases from hepatocellular carcinoma: multiple fractions compared with an 8-Gy single fraction.

External beam radiotherapy (EBRT) for hepatocellular carcinoma (HCC) bone metastases has not been popular in palliative therapy, and optimum dose schedules have not been decided because of limited published reports. We here evaluated the palliative effect of EBRT for HCC bone metastases and compared the dose-response relationship between multiple fractions (MFs) and an 8-Gy single fraction (SF). Twenty-eight patients (42 sites) with painful bone metastases who received EBRT and were analyzed retrospectively. Eight patients (12 sites) received SF. Of the remaining 20 patients (30 sites), 10 received MFs at moderate doses (20-30 Gy; 17 sites) and 10 received MFs at high doses (36-52 Gy; 13 sites). Overall response was achieved at 83% (35) of all sites; 75% (9) and 87% (26) for the SF and MF patients (88%, moderate dose; 85%, high dose), respectively. No significant differences in overall response were observed between each fraction schedule. Response duration was significantly longer for the high-dose MF patients than for the SF patients and moderate-dose MF patients (P < 0.05). SF was as effective as MF radiotherapy in terms of pain relief, but high-dose MF delivery relieved pain for a significantly longer duration.