Congress:
EuroSafe Imaging 2019
Keywords:
Action 2 - Clinical diagnostic reference levels (DRLs), Radioprotection / Radiation dose, Radiation physics, CT, Radiation safety, Quality assurance
Authors:
C. M. de Oliveira, A. Turcati Accorsi, L. Vinicius de Moura, A. Bacelar, M. ANÉS
DOI:
10.26044/esi2019/ESI-0052
Background/introduction
Computed Tomography (CT) is a very important tool for diagnostics in many fields of medical expertise.
Organisation for Economic Co-operation and Development data shows that in most countries CT exams have doubled in the last decade [1].
This recent scenario has pointed CT as the imaging modality that compromise about half the radiation dose on medical exposures [2;3] making the medical community aware of the need for optimized use of this resource.
Diagnostic Reference Levels (DRL) are defined in ICRP 135 as a form of investigation level to aid on optimisation of protection in the medical exposure of patients for diagnostic and interventional procedures [4].
DRL investigates and determines reference values of dose-related quantities for a standard-sized patient during medical radiodiagnostic practices or procedures.
Recently,
ICRP gave guidance in the DRL process through their publication 135,
clarifying the methodology suggested when determining DRL Values.
In Brazil the National Health Government rules the practice of radiation usage on medical services through the federal regulation number 453 published on 1998 [5].
This regulation establishes the DRL for CT exams performed on adult patients to abdomen (25 mGy),
lumbar spine (35 mGy) and skull (50 mGy),
but the DRL quantity referred remains the Multiple Scan Average Dose (MSAD),
an outdated CT dosimetry metric.
ICRP 135 recommends the volume computed tomography dose index (CTDIvol) and dose length product (DLP) as the practical dose quantities to be used to monitor practice.
To move on the same direction of ICRP 135 and cooperate to radiological protection on CT exames,
the aim of this study is to establish Local DRL Values for head,
chest and abdomen exams using the ICRP proposed methodology for adult patients.
We will evaluate the best strategy to define the standard patient comparing the two patient size information available,
weight and effective diameter and the relationship of dose quantities and CT equipment differences.