Establishment of Diagnostic Reference Levels in Portuguese Interventional Radiology departments.

Purpose: To establish Portuguese Diagnostic Reference Levels (DRLs), for six body fluoroscopy guided interventional procedures (FGIP).

Method: A retrospective study was conducted in five interventional departments most representative of Interventional Radiology (IR) practice. Dose values, in terms of air kerma area product (P in Gy.cm), air kerma at the patient entrance reference point (K in mGy), and exposure parameters (fluoroscopy time (FT) and number of cine runs) were collected. Examinations were selected per procedure (at least 20), according to the antero-posterior and lateral diameter mean value (±5 cm), measured on previous Computed Tomography (CT) examinations.

Results: Data of 489 body FGIP show a large variation on dose values per procedure and per department. National DRLs in terms of P were 20.2 Gy.cm for Percutaneous transhepatic biliary drainage (PTBD), 98.2 Gy.cm for Bronchial artery embolisation (BAE), 247.7 Gy.cm for Transarterial chemoembolisation (TACE), 331.6 Gy.cm for Inferior epigastric arteries embolisation (IEAE), 312.0 Gy.cm for Transjugular intrahepatic portosystemic shunt (TIPS) and 19.3 Gy.cm for Endovascular treatment of femoral popliteal arteries (ETFPA).

Conclusions: This is the first study reporting Interventional Radiology DRLs in Portugal and we propose preliminary national estimates for the six more common body FGIP. The results of this study will be presented and discussed with all Portuguese IR departments, to promote procedures optimisation.