Patterns of Rectal Cancer Radiotherapy Adopting Evidence-Based Medicine: An Analysis of the National Database from 2005 to 2016

Purpose:Not many studies have evaluated the adoption and dissemination of evidence-based medicine in rectal cancer radiotherapy (RT). We aimed to analyze the differences by institutional characteristics and geography in adopting evidence-based care for rectal cancer RT and factors affecting the adoption in Korea. Materials and Methods:Korean National Health Insurance Service claims database was used. All rectal cancer patients treated with radical surgery and adjuvant RT at the same institution in 2005-2016 were included in this study. RT within 3 months before and after surgery was regarded as preoperative and postoperative RT, respectively. Results:A total of 16,827 patients treated in 83 institutions were included in the analysis. The use of preoperative RT has substantially increased over time, from 40.6% in 2005 to 84.2% in 2016 all over the nation. The proportion of preoperative RT (54.8%) exceeded that of postoperative RT (45.2%) in 2006. However, a wide range of institutional and regional variation was observed. Compared to high-volume institutions, low-volume institutions showed late adoption and variable dissemination patterns of preoperative RT. Busan-Ulsan-Gyeongsangnam-do and Gangwon-do showed slower adoption and less use of preoperative RT than other region. Conclusion:We demonstrated gradual and steady increase in adoption of preoperative RT in rectal cancer treatment nationally from 2005 to 2016. Institutional variations between high- and low-volume institutions were observed.