Analysis of repeated computed tomography scans and cumulative effective dose of patients in a hospital

Computed tomography exams are considered diagnostic imaging exams that generate significant radiation dose to the patient. Justification, optimization, and dose limitation are radiological protection principles used to minimize patient and staff exposure, ensuring the quality of the service provided. The objective of this study was to analyze CT scan data, analyzing the number of exams, the patients' effective cumulated dose, and the repeatability of the exams. The study data covers the 2013 to 2022 period during which a progressive increase was observed in the number of exams performed over time, with exams doubling in this period. The most used Computed Tomography protocols were brain/skull (27.4%), pelvis (17.3%), and abdomen (13.7%) during the study period. Approximately 76.3% of patients have a cumulative dose of less than 25 mSv, while about 1% accumulated more than 100 mSv. The repeatability of CT scans for the same patient over a short period varies, reaching until 17 scans in 30 days for a single patient. The results indicated a necessity to develop strategies for individual dose management methods for the institution’s internal practices. An intervention could be implemented by creating periodically updated handouts and guidelines based on professionals' knowledge.