Evidence-Based Practice in the Global Setting: An International Survey of Hypofractionation

Abstract

Multiple large clinical trials have established the equivalence or non-inferiority of hypofractionated radiotherapy compared to conventionally fractionated treatment. The objective of this study is to determine real-world variations in the adoption of hypofractionation across different geographic regions and practice settings for cancers of the breast, prostate, and cervix, and for bone metastases, and barriers and facilitators to such adoption. An anonymous, electronic survey was distributed from January to December 2018 in English, Spanish, and Mandarin to radiation oncologists through the ESTRO Global Impact of Radiotherapy in Oncology initiative. There were 2,259 respondents from Europe (56%), Asia Pacific (19%), Middle East (5%), 12% Latin America, (12%), North America (6%), and Africa (2%). This survey assessed preference for hypofractionation and specific fractionation regimens across 4 disease sites (breast, prostate, cervix, and bone metastases) in curative and palliative scenarios. Perceived barriers and facilitators to adoption were evaluated. In regression analyses, hypofractionation preference was defined as use of hypofractionation for >75% of patients within each disease site and in >50% of clinical scenarios overall. Hypofractionation preference was more common in node-negative than in node-positive breast cancer (83% vs 46%, respectively; p<0.001), in low- and intermediate- vs. high-risk prostate cancer or cases requiring pelvic irradiation (56% vs. 32%, respectively; p=0.00001); hypofractionation was more common in North America and Europe than other regions. In cervix cancer, hypofractionation was preferred in 30% of locally advanced cervical cancer cases in Africa, but in <10% of cases in other regions. For palliative symptom control, hypofractionation was preferred by 93%, 91%, and 84% of respondents for breast cancer, prostate cancer, and cervix cancer respectively, and in 95% for bone metastases (p<0.001) across geographic regions. Lack of long-term data, inferior local control, toxicity, and inadequate technology were the most commonly cited barriers. In adjusted analyses, hypofractionation preference was associated with age <55 (odds ratio [OR] = 1.46, 95% CI 1.23 to 1.88), practice in a high-income country (OR=2.72, 95% CI 2.12 to 3.49), in a university setting (OR=1.30, 95% CI 1.04 to 1.67), in a center with a catchment area with >1,000,000 population (OR=1.57, 95% CI 1. to 2.0), and with intensity modulated radiotherapy (OR=1.70, 95% CI 1.22 to 2.34). Significant variation was observed in preference for hypofractionation across indications and between geographic regions, with greater concordance in preference for palliative indications. Improving the cost-effectiveness of radiotherapy and the quality of care delivered requires greater international attention to continuing medical education and policy reform that aligns evidence-based practice with physician incentives.