Cumulative doses from computed tomography 2014-2017

Descriptive analysis of a population at the Clínicas Hospital

Abstract

Introduction and objective: the rising use of computed tomography results in an increase in the collective doses with the potential risk for ionizing radiation. The study aimed at determining the frequency of repeated scans and at estimating the cumulative radiation doses between 2014 and 2017 in a sample of patients seen during July/August of 2017 at the Clinicas Hospital.

Method: patients who consulted at the Imagenology Department of the Clinicas Hospital in July and August, 2017 whose treating physician indicated a computed tomography were included in the study. It consisted of a descriptive, longitudinal, retrospective study. A spread sheet with demographic data and procedure was filled out and previous tomographic studies were looked for in the medical images file system, and reports issued in the last 3 years were analysed.

Results: 110 patients made up the sample; more than one tomography was performed to 59 (54.1%) patients underwent more than one scan, abdominal and pelvic scans being the most frequent. 7 patients (6.4%) surpassed the 100 mSv dose threshold and 16 (14.5%) received doses between 50 and 100 mSv. Likewise, 23 patients (20.9%) underwent more than 4 tomographies, that is more than one per year.

Conclusions:computed tomography is a beneficious diagnostic tool, provided it is used rationally upon a risk/benefit balance analysis. Awareness needs to be raised in relation to the risks associated to cumulative doses from multiple scans