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
Conclusion and recommendations
Local DRLs were determined for Head,
Chest and Abdomen exams in a university hospital from Brazil.
Two methodologies were considered to determine DRL,
setting the standard patient using the patient’s weight and using the patient’s effective diameter.
CTDIvol and DLP median and 75th percentile found were similar for the two methods,
suggesting that both can be used for patient standardization.
Even though effective diameter considers the irradiated anatomy and weight is one of many quantities related to the patient’s body type,
weight is a more accessible metric,
and therefore DRLs for chest and abdomen were determined through groups Chest-W and Abdomen-W.
DRL values found for CTDIvol and DLP were,
respectively,
77 mGy and 1504 mGy.cm for head exams,
17 mGy and 563 mGy.cm for chest exams and 22 mGy and 825 mGy.cm for abdomen exams.
Determined DRLs were compared with DRLs from other regions and countries on the table below [6-9].
Exam |
HCPA 2018 |
Egypt 2017 |
Japan 2015 |
Europe 2010 |
USA 2017 |
CTDIvol |
DLP |
CTDIvol |
DLP |
CTDIvol |
DLP |
CTDIvol |
DLP |
CTDIvol |
DLP |
Abdomen |
22 |
825 |
31 |
1323 |
20 |
1000 |
25 |
800 |
16 |
781 |
Chest |
17 |
563 |
22,3 |
421 |
15 |
550 |
10 |
400 |
12 |
443 |
Head |
77 |
1504 |
30 |
978 |
85 |
1350 |
60 |
1000 |
56 |
962 |
DRL established for CTDIvol for head,
chest and abdomen exams was higher than most references.
DRL set for DLP for chest and head exams was also higher than most references,
however the DLP for the abdomen exams agree with the references.
Even though population and socio economics factors must be considered when comparing DRLs from different regions,
data indicates the need of protocol standardization and further optimization.
This study is also a step towards national DRL establishment in Brazil.