Establishing Dose Reference Levels for CT in a Chilean Hospital including technologist performance

Congress:

EuroSafe Imaging 2019

Poster Number:

ESI-0101

Type:

EuroSafe Imaging

Keywords:

Dosimetric comparison, Dosimetry, CT, Radioprotection / Radiation dose, Radiation physics, Action 4 - Dose management systems, Action 2 - Clinical diagnostic reference levels (DRLs), Quality assurance

Authors:

D. Fabri, P. Soffia, J. Sanguesa, R. Castillo

DOI:

10.26044/esi2019/ESI-0101

DOI-Link:

https://dx.doi.org/10.26044/esi2019/ESI-0101

Background/introduction

Medical exposures with ionizing radiation are the main source of exposure to artificial radiation at a global level. This is due to the significant increase use of high doses procedures, particularly computed tomography (CT) [1]. According to the International Commission on Radiological Protection (ICRP), limits of dose for individual patients should not be used, and optimizing protection to radiation dose to patient must be done by means of Diagnostic Reference Levels (DRLs).

DRLs are numerical values of some dose indicator, which depends on the modality of the study and the procedure. For CT the dose indicators used are CTDI_vol and /or DLP. For an individual medical center the DRL corresponds to the median (50th percentile) of the observed values according to ICRP Report No. 135 [2]. To work on the optimization process the institutional DRL should be compare with published DRLs.

Usually published DRLs correspond to the 75th percentile of the distribution of the individual center DRLs that are participating in large-scale studies.

The published DRLs may correspond to; local values, when a few centers are included having in total an order of 10 to 20 rooms (LDRL). National DRLs (NDRLs) data collection represents a country (NDRL). Moreover, Regional DRLs when data from several countries are consider within a continent (RDRL).

The ICRP recommends annual audits of DRLs for CT, especially if an automated system for the collection and management of patient data is available.

Although in Europe and the US the patient dose index register is being demand by regulatory and accreditation entities, it is difficult to find records of radiation dose in Latin America and there is no formal establishment of NDRLs or RDRLs.

On this work we present the establishment of DRL values for CT exams perform at Clinica Alemana in Chile during the year 2018 and the comparison of our findings with data published by Khan et al. on 2017 [3]. We finally also observe the performance of radiographers in terms of delivered dose, for a couple of specific protocol.