Emergency Department Visits After Radiotherapy in Patients with Solid Malignancies: Analysis of Causality and Severity

Background: This study aimed to characterize emergency department (ED) visits after radiotherapy (RT) and to assess the causality and severity of these visits. Methods: Patients who received RT for solid malignancies from 2016 to 2021 were retrospectively analyzed. The study period for ED visits was defined from the start of RT to 3 months after the completion of RT. Causes of ED visits were classified as 1) cancer treatment-related causes, 2) RT-related causes, 3) cancer-related causes, and 4) other medical conditions, and the degree of relevance for each cause was assessed as 1) certain, 2) probable, 3) possible, or 4) unlikely. Severity was graded using the Korean Triage and Acuity Scale (KTAS). Acuity at ED presentation was categorized by KTAS grade: grades 1–2 as high, grade 3 as moderate, and grades 4–5 as low. Predictors related to strong relevance (certain and probable) for each cause and to severe events were examined using binary logistic regression. A p-value 30 days after RT (OR 2.60, p=0.016), and age ≥65 years (OR 2.37, p=0.022). Conclusion: Patients with identified risk factors require close and continuous follow-up after RT to reduce severe ED presentations.