Monitoring of radiation dose using dose tracking software in a neurovascular intervention room

Transcription

1 Monitoring of radiation dose using dose tracking software in a neurovascular intervention room Poster No.: ESI-0017 Congress: EuroSafe Imaging 2017 Type: EuroSafe Imaging Authors: H. Acton 1, K. James 1, F. Moloney 1, N. Fanning 2, G. Wyse 3, M. M. Maher 1, O. O'Connor 1 ; 1 Cork/IE, 2 University Hospital Cork/IE, 3 Cork University Hospital Cork/IE Keywords: DOI: Embolism / Thrombosis, Arteriovenous malformations, Aneurysms, Embolisation, Diagnostic procedure, Arterial access, Fluoroscopy, Radioprotection / Radiation dose, Interventional vascular, CNS, Action 6 - Education and training in medical radiation protection, Action 3 - Optimisation, diagnostic reference levels, image quality, Action 2 - Clinical audit /esi2017/ESI-0017 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Page 1 of 12

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3 Background/Introduction Neurointerventional procedures have the potential for greater radiation exposure compared with other radiological procedures. While the benefits of the procedures outweigh the risks, patient radiation exposure can cause adverse effects such as radiation burn, cataracts and malignancy and should be kept as low as possible. Article 56(1) of the European Union Directive 2013/59/Euratom requires that all member states ensure that radiation doses for interventional procedures are kept as low as reasonably achieveable. Article 56(2) states that all member states must ensure the establishment, and use of diagnostic reference levels for radiodiagnostic examinations, and where appropriate, interventional radiology procedures[1]. The introduction of dose tracking software in Ireland is a welcome addition to radiology departments to aid in patient dose monitoring. Dose tracking software allows faster analysis of patient dose, decreased risk of input error, and alert to increased dose. The use of dose monitoring software will aid in analysis of patient dose levels with the end goal of producing accurate national dose reference levels for individual types of neurointerventional procedures (which is currently lacking). Combining this data with national hospitals performing such procedures will allow for the formation of national dose reference guidelines for these procedures which can be used national as guidelines and as a reference both within the European Union and internationally. Aim The aim for this study was to analyse neurointerventional radiation dose levels using dose-tracking software to find determinants of increased radiation dose Objectives Review radiation dose for neurointerventional procedures performed over a one-year period Analyse aneurysm coiling procedure variables to determine dose technique relationships Page 3 of 12

4 Description of activity and work performed Methods A retrospective cohort study was performed at Cork University Hospital, in Cork, Ireland. Radiation dose was measured using Dose Area Product (DAP) measured in mgy.cm 2. Data collection was carried out on the Picture Archiving and Communication System (Impax 6.5.3; Agfa Healthcare, Morstel, Belgium) and dose tracking software (DoseWatch, GE, Milwaukee, WI). Cases were excluded if dose level data was missing. Additional variable data on aneurysm coiling procedures was provided by a prospectively gathered patient procedure database continuously maintained by a consultant neurointerventional radiologist. Statistical analysis was performed using IBM SPSS software version 23. Two hundred and sixty-four patients who underwent neurointerventional procedures at Cork University Hospital between November 2014 and November 2015 were selected. thirty-two cases were excluded due to insufficient data. twenty-two of these cases were diagnostic; The remaining ten were therapeutic. Four neurointerventional procedures were studied: (1) four vessel angiogram, (2) aneurysm coiling, (3) arteriovenous malformation embolization, and (4) stroke thrombolysis/thrombectomy. One hundred and nine aneurysm coiling procedures were selected for the second objective, including cases selected for objective 1. the remaining cases were collected from the end period of objective 1 (November 2015) to September Results: Objective 1 Procedure type Of the two-hundred and sixty-four procedures selected, one hundred and eighty nine were four-vessel angiograms, fifty-nine were aneurysm coiling procedures, ten were stroke thrombolysis/thrombectomy, and six were arteriovenous malformation embolization. Patient demographic Sixty-one percent of patients were female and thirty-nine percent were male. Procedures distinguished by sex differed substantially. The number of aneurysm coiling procedures Page 4 of 12

5 performed on women was 3.7 times the number performed on men. Overall, women were more likely to undergo both diagnostic and therapeutic procedures. Patient age was categorized into groups of equal distribution and numbered for data analysis. Patients aged (group 4) had the highest number of therapeutic procedures performed. Patients aged (groups 4 and 5) shared the highest number of overall procedures performed. Radiation dose The median radiation DAP for diagnostic angiography (four-vessel angiogram) was 73.7 Gy.cm 2 (DAP range ). The remaining procedures were therapeutic. The median DAP for aneurysm coiling was Gy.cm 2 (DAP range ). The median DAP for arteriovenous malformation embolization was Gy.cm 2 (DAP range ), the median DAP for stroke thrombolysis/thrombectomy was 87 Gy.cm 2 (DAP range ). The Health Services Executive (Irish health service) have published dose reference levels (75th percentile DAP) for other interventional procedures. Other interventional procedures generally have lower DAP. For example, the DRL for a barium enema is 47 Gy.Cm 2, however, the DRL for a transjugular intrahepatic portosystemic shunt procedure (TIPS), a more complicated procedure, and more comparable to a challenging embolisation is referenced at Gy.cm 2 [2][3]. A number of outliers were found for both aneurysm coiling and four-vessel angiogram groups. The patient case files were reviewed on PACS to determine possible causes for the increased doses. Five of the six four-vessel angiogram outlier cases had arteriovenous malformations which required addiation imaging projections and more contrast studies than normal. Three of the five-aneurysm coiling procedure outliers were posterior circulation aneurysm with/without anterior circulation aneurysms. The two remaining cases were anterior circulation aneurysms developed complications, such as coil herniation and vasospasm. Results: Objective 2 Aneurysm coiling variables were analysed to determined variables that had a significant effect on radiation dose to the patient. Overall, nine variables were found to have a significant effect ( Table 3 on page 7 ). These variables were then analysed further to determine what vairable had the single biggest effect on radiation dose. Page 5 of 12

6 Overall, aneurysm location (posterior circulation vs. anterior circulation) was found to have the single biggest effect on radiation dose (p=.004, see Table 4 on page 8 ). Images for this section: Table 1: Summary of DAP measurement for neurointerventional procedures - Cork/IE Page 6 of 12

7 Fig. 3: Box-plot chart depicting DAP for neurointerventional procedures - Cork/IE Table 2: DAP percentiles for each neurointerventional procedure - Cork/IE Page 7 of 12

8 Table 3: Aneurysm coiling variables affecting DAP - Cork/IE Table 4: Aneurysm location - Cork/IE Page 8 of 12

9 Conclusion and Recommendations Exposure of the patient to high levels of radiation is a serious risk when performing neurointerventional procedures. It is the duty of the neurointerventional radiologist and team to perform the procedure to the best of their ability whilst also minimizing radiation exposure for the patient. The results of this study show that a patient undergoing a neurointerventional procedure will be subjected to variable radiation exposures depending on the abnormality and/or vascular location. These results demonstrate which patient sub groups are at increased risk for higher exposure, which has prompted review of techniques to help optimise radiation dose to the patient. This data is also useful for the purposes of patient consent where radiation dose should be discussed if a high radiation dose is anticipated. In addition the present data have implications for staff exposures especially in the context of tighter limits on operator eye doses proposed in Euratom Personal/Organisational information Holly Acton, Final Year Medical Student, University College Cork, Ireland Karl James, Radiology Specialist Registrar, Cork University Hospital, Ireland Fiachra Moloney, Radiology Fellow (MSK), Ontario, Canada Noel Fanning, Consultant Neuroradiologist, Cork University Hospital, Ireland Gerald Wyse, Consultant Neuroradiologist, Cork University Hospital, Ireland Michael Maher, Consultant Radiologist and Professor of Radiology UCC/Cork and Mercy University Hospitals, Ireland Owen O'Connor, Consultant Radiologist and Senior Lecturer UCC/Cork and Mercy University Hospitals, Ireland Page 9 of 12

10 Images for this section: Fig. 1 Cork University Hospital Page 10 of 12

11 Fig. 2 University College Cork Page 11 of 12

12 References [1] Council Directive 2013/59/Euratom of 5 December 2013 laying down basic safety standards for protection against the dangers arising from exposure to ionizing radiation and repealing Directives 89/618/Euratom, 90/641/Euratom, 92/29/Euratom, 97/43 Euratom and 2003/122/Euratom [2] Medical Council. Diagnostic Reference Levels: Position Paper. September safepatientcare/medexpradiatonunit/diagnostic_reference_levels.pdf [3]HSE. Template for developing a Patient Radiation Protection Manual. August medexpradiatonunit/rp%20manual% pdf Page 12 of 12