Practice disparities in palliative radiation therapy for bone metastases: insights from the Shizuoka Kokuho database study.

purposePalliative radiation therapy (pRT) is a standard treatment option for bone metastases from malignancies and is recommended in current guidelines. Patients should have an equal opportunity to receive pRT regardless of their residential address or the location of the treatment facility; however, the frequency of use of pRT varied across regions and healthcare systems in studies in North America. This study aimed to examine the disparity in Japan. MATERIALS AND

methodsWe conducted a historical cohort study using a regional population-based cohort that included medical insurance data to examine practice disparities in pRT for patients diagnosed with bone metastases who received bone-modifying agents (BMA). The analyses focused on the secondary medical areas (SMA) where the patients lived and facilities where they were treated.

resultsOverall, 6289 patients were included in our study, and 39.6% received pRT. The regional disparity in the proportion of pRT delivery was not large, despite some areas having no facilities with RT devices. However, differences among facilities where BMA was initiated were substantial. The BMA facilities with RT devices had a higher proportion of pRT than those without RT devices. In addition, the difference was wide among the facilities with RT devices. Patients treated with BMA in designated cancer hospitals were likely to receive pRT than those of other hospitals.

conclusionThis population-based study using medical claims data demonstrated practice disparities in pRT for bone metastases, particularly at the facility level. To improve this disparity, facility-level strategies seem to be more effective than SMA-level approaches.