Continuing reluctance to use single fractions of radiotherapy for metastatic bone pain: an Australian and New Zealand practice survey and literature review

Abstract

Purpose: To survey Australian and New Zealand (ANZ) radiation oncologists on their preferred fractionation regimens for pain due to bone metastases in the context of similar overseas surveys and the large body of evidence from randomized trials.

Methods: Delegates to the October 1998 Royal ANZ College of Radiologists Annual Scientific Meeting were asked to state their fractionation for four hypothetical cases viz. local bone pain from metastatic breast, prostate and lung cancer and neuropathic (radicular) pain from metastatic lung cancer. In addition to demographic data, respondents were asked to select reasons for their choices and indicate what factors would influence a change in their recommended fractionation.

Results: Twelve of 32 trainees and 41 of 82 specialists completed the survey, giving an overall response rate of 46%. There was decreasing use of shorter fractionation schedules from lung through prostate to breast cancer with, in particular, single fractions recommended by, respectively, 42, 28 and 15% of respondents for local bone pain (P=0.013). However, the presence of neuropathic pain from metastatic lung cancer led to lower use of single fractions (15%, P=0.0046). There were no statistically significant differences in preferred fractionation with respect to other variables assessed in this survey. The commonest reasons cited for fractionating were desire to minimize recurrent pain and the influence of training, with desire to minimize the risk of neurological progression and optimize tumour regression also important for neuropathic pain. By contrast, use of single fractions was most commonly based upon literature results and patient convenience. Changing from multiple to single fractions was most influenced by poor performance status, while the presence of neurological signs/symptoms had the reverse effect.

Conclusions: The findings from this ANZ survey largely reflect the results from other surveys performed in the UK, Europe, Canada and USA. Although debate continues in the literature, the continuing preference of radiation oncologists to fractionate for local bone pain is contrary to the 16 randomized trials published to date which give little support for a dose-response relationship above a single 6-8 Gy in this setting. This practice has significant implications for departmental workload, costs to the healthcare system and patient convenience. There is no objective evidence on the influence of fractionation for neuropathic bone pain in the literature at present, although an ANZ randomized trial addressing this problem is under way (TROG 96.05).