EuroSafe Imaging 2020
Action 4 - Dose management systems, Radioprotection / Radiation dose, CT, Digital radiography, Computer Applications-General, Dosimetric comparison, Not applicable, Performed at one institution
A. Steuwe, O. T. Bethge, J. Boos, J. Böven, J. Morawitz, L. M. Sawicki, G. Antoch, J. Aissa
Patients undergoing radiological examinations such as radiography or computed tomography (CT) are exposed to ionizing radiation. Ionizing radiation can lead to the induction of point mutations in the DNA, chromosomal translocations and gene fusions, which are linked to the induction of cancer . The usage of ionizing radiation in CT and radiography is double-edged: On the one hand, it is aimed for the lowest radiation exposure to reduce the likelihood of developing a radiation-induced tumor. On the other hand, the image quality decreases with decreasing radiation exposure, potentially causing non-diagnostic images and/or a repetition of the examination with a higher radiation exposure. The “ALARA” principle (as low as reasonably achievable) tries to meet both requirements of diagnostic image quality and patient safety.
Furthermore, diagnostic reference levels (DRLs) were determined to prevent an unnecessary high use of radiation exposures for different examination types. DRLs provide dose levels as guide for typical examinations for groups of standard-sized patients and modern modalities and are age- or habitus-dependent for pediatric patients. For CT, DRLs are provided as volumetric CT dose index (CTDIvol in mGy) and dose length product (DLP in mGy*cm). For radiography, DRLs are provided as dose area product (DAP, in cGycm²). These dose parameters are provided by the imaging modality for every examination in modern modalities.
The European directive 2013/59/Euratom requires management of exposure data, detection of dose outliers and, in addition, explanation of DRL-exceedances. In case of DRL-exceedances, dose management helps to differentiate between modality-specific problems (e.g. disadvantageously adjusted acquisition protocols) and patient-specific problems (e.g. adipose patients). Especially in larger hospitals, dose management is only achievable with a dedicated dose management system (DMS).