Single versus conventional fractionated radiotherapy in the palliation of painful bone metastases

Abstract

Aim: To compare a single 8 Gy fraction with conventional regimen of 40 Gy in 20 fractions as a palliative treatment to patients with bone metastasis and reducing the treatment burden for both the patients and Hospital Staff.

Methods: One hundred and seven patients with painful localized bone metastases requiring palliative radiotherapy were entered into a prospective randomized trial comparing 8 Gy single fraction (SF group) with 40 Gy in 20 fractions, five fractions/week (CF group). The primary tumor was in the breast in (48.1%) of the patients, in the lung in (20.6%) in the prostate in (17.6%), and in other sites in (13.7%). Bone metastases were located in the spine (42.2%), pelvis (29.4%) limbs (21.6%), and other sites (6.8%). Pain relief was measured by visual analogue scale (VAS) and also by analgesic requirement. Evaluation was performed before and at 2 weeks then every 4 weeks for 24 weeks after treatment. A total of 102 patients were evaluable for response; 50 in the SF group and 52 in the CF group.

Results: There were no significant diferences in the frequency or duration of pain relief between the two study groups. In both groups, the maximum benefit was achieved at 8 weeks after treatment; 41 patients (82%) in SF group and (44%) of those in the CF group. The frequency of pain by > or =50% on VAS. Complete pain relief was reported in (44%) of those in the CF group. The frequency of pain relief did not differ between the two groups with respect to the primary tumor, the metastatic sites, and the performance status, but for patients as a whole, there was a significantly lower response rate for lung cancer patients (61.9%) in comparision to patients with breast (91.8%) and prostate (100%) cancer. The median duration of pain relief was 12 weeks in the SF group and 13.5 weeks in CF group. During follow-up, 7 patients (6 in SF group and one in CF group) had their bone metastases re-irradiated. Six of these re-irradiated patients also achieved pain relief.

Conclusion: This study indicates that a single fraction of 8 Gy is as effective as 40 Gy in 20 fractions for the palliation of painful bone metastases. Single fraction schedule may be preferred for patient convenience and an option for re-treatment in the case of recurrent pain.