The impact of radiation treatment planning technique on unplanned hospital admissions

PURPOSE: Treatment burdens and toxicities related to palliative radiation therapy (RT) may lead to unplanned hospital admissions (UHAs). The likelihood for these toxicities may be related to treatment technique. We compared rates of UHA between patients receiving nonconformal (2-dimensional) and conformal (3-dimensional or higher) radiation treatments to bone metastases involving the vertebral column. METHODS AND MATERIALS: We retrospectively analyzed patients treated with RT for bone metastases at a single tertiary care center between 2010 and 2017. We compared rates of RT-related UHA within 90 days of receiving radiation using Cox competing risk regression models. RESULTS: We identified 326 patients with bone metastases involving the vertebral column, 139 of whom received radiation by nonconformal technique and 187 by conformal technique. On multivariable analysis, conformal techniques were associated with a reduced risk of 90-day UHA (hazard ratio [HR]: 0.35; 95% confidence interval [CI], 0.14-0.88). Other significant factors include hematologic cancer (HR: 0.17; 95% CI, 0.03-0.82) and baseline Eastern Cooperative Oncology Group score ≥2 (HR: 3.02; 95% CI, 1.05-8.69). CONCLUSIONS: The utilization of conformal (non-2-dimensional) radiation treatment plans may help reduce treatment-related toxicities and consequently UHAs after palliation of bone metastases.