Congress:
EuroSafe Imaging 2019
Keywords:
Action 2 - Clinical diagnostic reference levels (DRLs), Action 4 - Dose management systems, Thorax, Radiation physics, Radioprotection / Radiation dose, CT, Physics, Radiation safety, Statistics, Dosimetric comparison
Authors:
N. Saltybaeva, H. Alkadhi
DOI:
10.26044/esi2019/ESI-0061
Description of activity and work performed
Data collection
Dose data of various CT procedures performed within the last 12 months were electronically collected by dose tracking software (DOSE,
Qaelum NV,
Belgium) using CT DICOM radiation dose structure reports.
The dose metrics together with patient-specific parameters were collected from five chest CT protocols used for the following indications: pulmonary embolism (PE),
lung cancer (LC),
lung nodule follow-up (LNFU) and coronary CT angiography (CCTA).
Data analysis
The data was filtered to remove the scout view,
monitoring and pre-monitoring acquisitions.
The dose length product (DLP) and volume CT dose index (CTDIvol) were recorded and the clinical DRLs were defined as the 75th percentile of these metrics’ distributions.
The established DRLs were compared to the NDRLs.
Pearson’s correlation was used to determine the relationship between CTDIvol and patient weight.
Compliance monitoring
Besides the DRLs we established the “local limits” (LL) defined as the CTDIvol and DLP above the 98th percentile of their distributions.
The CT examinations with CTDIvol and/or DLP above the LL were defined as the outliers and were investigated individually.
The dose tracking tool allowed to continuously evaluate compliance of clinical DRLs with the LL.
Whenever the LL levels were surpassed,
the system sent an electronic notification to the dedicated working group.