National diagnostic reference levels for fluoroscopy-guided procedures in Gastroenterology, Urology and Pediatric Cardiology Eleni-Theano Samara, Abbas Aroua, Barbara Ott, Philipp R. Trueb and Francis R. Verdun Workshop on European Population Doses from Medical Exposure 24-26 April 2012, Athens, Greece
Diagnostic Reference Levels (DRLs) Frequency 25 th percentile 75 th percentile Dose indicator Optimization tool Machine indications Most dose histograms are skewed distributions Optimization studies should concentrate on 25%
Swiss DRLs* Radiography examinations CT examinations Pediatrics (newborn, 1-5, 6-10, 11-15 years-old) Target value: 25 th percentile Fluoroscopy procedures Diagnostic procedures Therapeutic procedures Nuclear Medicine *www.bag.admin.ch
OSUR* Objectives: 1. Determination of the national DRLs 2.Evaluation of the existing DRLs with respect to current medical technique 3. Adjustment of current DRLs 4. Update average dose data for population survey *Optimierung des Strahlenschutzes bei dosisintensiven Untersuchungen in der Radiologie
OSUR Interventional procedures in the past o Interventional radiology Angiography of the lower limbs Percutaneous transluminal angioplasty of the lower limbs o Interventional cardiology Coronary angiography Percutaneous coronary intervention o Urology o Gastroenterology o Pediatric cardiology o Orthopedics Present (and future?)
OSUR Data collection for interventional procedures o Radiation exposure of patient Dose-area product (DAP) Fluoroscopy time (T) Number of images (N) obtained during the procedure o Patient demographics Height Weight Age o Procedure difficulty : simple normal complex o Physician s experience: resident junior senior o Type of hospital: academic non-academic centre o Inter-comparison between hospitals Student T-tests (SPSS Inc.)
Urology Percutaneous nephrostomy Retrograde urethropyelography Retrograde urethrography 2 university hospitals
Urology DAP (Gy cm 2 ) T (min) N Reference Retrograde urethrography Local diagnostic reference level as retrograde 25 - - Brambilla et al. cystourethrography Diagnostic reference level 20 - - ICRP 75 th percentile 5 2 - This study Retrograde ureteropyelography Diagnostic reference level as retrograde 13 3 - HPA pyelogram 75 th percentile 17 3 - This study [1] Brambilla M, Marano G, Dominietto M, Cotroneo AR, Carriero A. Patient radiation doses and references levels in interventional radiology Radiol Med. 107:408-18 2004 [2] Diagnostic reference levels in medical imaging: Review and additional advice [3] http://www.hpa.org.uk/topics/radiation/understandingradiation/understandingradiationtopics/medicalradiation/diagnosticradiology/raddiag_nationalreferencedoses/
Urology Percutaneous nephrostomy Red line: 75 th percentile of the distribution Green line: current national DRL Update of the current DRLs
Gastroenterology Endoscopic retrograde cholangiopancreatography(ercp) 2 university hospitals
Gastroenterology ERCP Current DRLs OK
Pediatric cardiology Aorta stenting Radiofrequency ablation (RFA) Atrial septal defect (ASD)
Pediatric cardiology Aorta stenting (2 University Hospitals) Significant difference was found (p-value=0.008) Hospital 75 th percentile values for two hospitals DAP (Gy.cm 2 ) T (min) Air- Kerma (mgy) N Notes Mean patient age 1 17.5 15.9 246.2 2216 10.7 y 2 9.5 13.7 - - 2.8 y
Pediatric cardiology ASD (2 University Hospitals) Significant difference in DAP values (p-value=0.009) DAP 1 = 7.2 DAP 2 = 15.5 Gy cm 2 Gy cm 2
Pediatric cardiology Radiofrequency ablation (1 University Hospital) Hospital 75 th percentile values for one hospital DAP (Gy.cm 2 ) T (min) Air- Kerma (mgy) N 1 17.5 15.9 246.2 2216 Local DRLs established
Orthopedics Vertebroplasty 0 hospitals (!)
Difficulties of the project o Data collection Paper form o Missing information DAP / T / N / Air-Kerma Physician experience o Procedure complexity evaluation
Conclusions of the project o Reports sent to the hospitals o Differences between the hospitals o Preliminary DRLs for new examinations oupdate of the national DRLs
Thank you for your attention!