International patterns of practice in palliative radiotherapy for painful bone metastases: evidence-based practice?

Purpose: Multiple randomized controlled trials have demonstrated the equivalence of multifraction and single-fraction (SF) radiotherapy for the palliation of painful bone metastases (BM). However, according to previous surveys, SF schedules remain underused. The objectives of this study were to determine the current patterns of practice internationally and to investigate the factors influencing this practice.

Methods And Materials: The members of three global radiation oncology professional organizations (American Society for Radiology Oncology [ASTRO], Canadian Association of Radiation Oncology [CARO], Royal Australian and New Zealand College of Radiologists) completed an Internet-based survey. The respondents described what radiotherapy dose fractionation they would recommend for 5 hypothetical cases describing patients with single or multiple painful BMs from breast, lung, or prostate cancer. Radiation oncologists rated the importance of patient, tumor, institution, and treatment factors, and descriptive statistics were compiled. The chi-square test was used for categorical variables and the Student t test for continuous variables. Logistic regression analysis identified predictors of the use of SF radiotherapy.

Results: A total of 962 respondents, three-quarters ASTRO members, described 101 different dose schedules in common use (range, 3 Gy/1 fraction to 60 Gy/20 fractions). The median dose overall was 30 Gy/10 fractions. SF schedules were used the least often by ASTRO members practicing in the United States and most often by CARO members. Case, membership affiliation, country of training, location of practice, and practice type were independently predictive of the use of SF. The principal factors considered when prescribing were prognosis, risk of spinal cord compression, and performance status.

Conclusion: Despite abundant evidence, most radiation oncologists continue to prescribe multifraction schedules for patients who fit the eligibility criteria of previous randomized controlled trials. Our results have confirmed a delay in the incorporation of evidence into practice for palliative radiotherapy for painful bone metastases.