Palliation of bone metastases: a survey of patterns of practice among Canadian radiation oncologists

Background: Palliative radiotherapy constitutes nearly 50% of the workload in radiotherapy. Surveys on the patterns of practice in radiotherapy have b een published from North America and Europe. Our objective was to determine the current pattern of practice of radiation oncologists in Canada for the palliation of bone metastases. Method: A survey was sent to 300 practicing radiation oncologists in Canada . Five case scenarios were presented. The first three were patients with a single symptomatic site: breast cancer patient with pelvic metastasis, lung cancer male with metastasis to L3 and L1. respectively. The last two were breast and prostate cancer patients with multiple symptomatic bone metastas es. Results: A total of 172 questionnaires were returned (57%) for a total of 8 60 responses. For the thr ee cases with a single painful bone metastasis. o ver 98% would prescribe radiotherapy. The doses ranged from a single 8 to 3 0 Gy in ten fractions. Of the 172 respondents, 117 (68%) would use the same dose fractionation for all three cases, suggesting that they had a standar d dose fractionation for palliative radiotherapy. The most common dose frac tionation was 20 Gy in five fractions used by 84/117 (72%), and 8 Gy in one fraction by 19/117 (16%). In all five case scenarios, 81% would use a shor t course of radiotherapy (single 8 Gy. 17%; 20 Gy in five fractions, 64%), while 10% would prescribe 30 Gy in tell fractions. For the two cases with d iffuse symptomatic bone metastases, half body irradiation (HBI) and radionu clides were recommended more frequently in prostate cancer than in breast c ancer (46/172 vs. 4/172, P < 0.0001;and 93/172 vs. 10/172, P < 0.0001, resp ectively). Strontium was the most commonly recommended radionuclide (98/103 = 95%). Since systemic radionuclides are not readily available in our heal th care system. 41/98 (42%) of radiation oncologists who would recommend st rontium were not familiar with the dose. Bisphosphonates were recommended m ore frequently in breast cancer than in prostate cancer 13/172 (8%) vs. 1/1 72 (0.6%), P = 0.001. Conclusion: Local field external radiotherapy remains the mainstay of thera py, and the most common fractionation for bone metastases in Canada is 20 G y in five fractions competed with 30 Gy in ten fractions in the US. Despite randomized trials showing similar results for single compared with fractio nated radiotherapy, the majority of us still advocate five fractions. The f requency of employing a single fractionation has not changed since the last national survey in 1992. Nearly 70% use a standard dose fractionation to p alliate localized painful metastasis by radiotherapy, independent of the si te of involvement or tumor type. The pattern of practice of palliative radi otherapy for bone metastases in Canada is different to that reported previo usly from the US. The reasons why the results of randomized studies on bone metastases have no impact on the patterns of practice are worth exploring. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.