Installation of a regional CT dose registry with a dose management software

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Installation of a regional CT dose registry wi a dose management software Poster No.: ESI-0036 Congress: EuroSafe Imaging 2016 Type: EuroSafe Imaging Auors: S. Schindera, A. Euler, A.

1 Installation of a regional CT dose registry wi a dose management software Poster No.: ESI-0036 Congress: EuroSafe Imaging 2016 Type: EuroSafe Imaging Auors: S. Schindera, A. Euler, A. Parakh ; Riehen/CH, Klinik für Radiologie und Nuklearmedizin Basel/CH, New Delhi/IN Keywords: Action 3 Diagnostic Reference Levels, Data collection, Image Quality DOI: /esi2016/ESI-0036 Any information contained in is pdf file is automatically generated from digital material submitted to EPOS by ird parties in e form of scientific presentations. References to any names, marks, products, or services of ird parties or hypertext links to irdparty 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 e ird party, information, product or service. ECR is not responsible for e content of ese pages and does not make any representations regarding e content or accuracy of material in is file. As per copyright regulations, any unauorised use of e material or parts ereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication meod 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 ese pages. Please note: Links to movies, ppt slideshows and any oer multimedia files are not available in e pdf version of presentations. Page 1 of 11

2 Background/Introduction Rising use of computed tomography (CT) has been documented due to its ubiquitous presence, ease of operation, short acquisition time, emerging applications and positive impact on patient roughput. Over e past 30 years e utilization of CT in e U.S. has been steadily growing at e rate of approximately 10% per year, approaching 80 million scans per annum (1). The rapid expansion comes at a cost of a higher radiation burden in comparison to oer imaging modalities. In Switzerland, albeit responsible for only 6% of diagnostic studies using ionizing radiation in 2008, CT was accountable for 68% of e annual medical radiation exposure (2). Such numbers indicate CT as a particular focus for patient protection initiatives and call for accountability. The main meods to address e increasing doses, until recently, have been proper justification of clinical examinations, optimization of scans and development of dose efficient technologies. The value of dose tracking and management has been largely over-sighted by virtue it of being a complex, manual and time-consuming task. Wi e development of radiation dose tracking softwares (RTS), it is now feasible to create a comprehensive CT dose management program since ey can seamlessly parse volumes of data into comprehensible user-friendly meaningful reports wi improved statistical certainty and reliability. RTS can track, analyze and archive various dosemetrics to obtain an aggregation of big-data and can erefore also help in creation of dose-registries at can be used for benchmarking. We decided to develop a regional CT dose registry in Switzerland using an RTS wi e aim to systematically track e doses of all CT scans performed at six different institutes and to compare e inter-institutional radiation doses. This data is en being used to perform meaningful benchmarking at local and national diagnostic reference levels. Description of activity and work performed Hospital Set-up, CT Scanner Specifications and IT Set-up st st Data for a period of two years (between January and December ) was automatically tracked wi a RTS (Radimetrics, Bayer HealCare, Whippany, NJ) from seven CT scanners installed at five medical institutions located in Nor-western Switzerland. There were ree regional hospitals, one private hospitals focusing on Page 2 of 11

3 geriatric care and a university hospital. Data from all hospitals came from one CT scanner except e university hospital (University Hospital Basel), which has ree CT scanners installed. The CT scanners represented a broad range in regards to geometry (16 to 256 slice) and dose reduction capabilities (e.g. five of seven have iterative reconstruction technique installed) (Fig. 1 on page 4). The same RTS (Radimetrics, Bayer HealCare) was installed at all five participating hospitals. The RTS was connected to PACS systems from four different vendors and extracted e radiation exposure details, stored in e Digital Imaging and Communications in Medicine (DICOM) header or Radiation Dose Structured Report. The dose-data was en relayed to ree local servers, where it was anonymized before being uploaded to a single master server called e patient dose repository. A dose-team was created in e university hospital, which consisted of a radiologist, technologist, medical physicist and IT specialist. The technologist from e dose-team visited e different facilities to standardize e nomenclature of all protocols and created 'master protocols'. The protocol standardization was performed wi e help of e Radlex playbook published by RSNA (3). This was done to link e various device protocols to a standard unified protocol and avoid comparison of 'apples wi oranges'. The radiologist (wi 11 years of experience wi CT dose optimization) confirmed e matching of all device protocols wi e master protocols to avoid mismatching and ensure reliable analyses of doses. Data was collected for e five most commonly performed single phase diagnostic CT examinations in adults; head (to rule out intracerebral hemorrhage), chest (to rule out pulmonary nodules or pneumonia), abdomen-pelvis (e.g. assessment of an acute abdomen), renal-colic protocol and CT pulmonary angiogram (to rule our embolism). The RTS provided values (mean, median and interquartile range; IQR) for e different dose metrics- volumetric dose index (CTDIvol), dose-leng product (DLP), size-specific dose estimate (SSDE) and effective dose (ED). Results and Analyses Overall, 82,580 diagnostic CT examinations were performed in adults in e two-year period. Of ese, 15,539 scans were of CT head (18.8% of all examinations), 7,343 scans were of CT orax (8.8 % of all), 5,828 scans were for abdomen-pelvis (7% of all), 3,364 examinations for CT pulmonary-angiogram (4% of all examinations) and 2,433 examinations were for uroliiasis (3% of all scans). The five protocols (34,507 examinations) amounted to 41.7 % of all examinations. Page 3 of 11

4 Inter-institutional Benchmarking Fig. 2 on page 6 enumerates e interquartile range (25, 50 and 75 percentile) of CTDIvol (in mgy) and DLP (in mgycm) values for all five protocols by e seven CT scanners. It reveals a wide variation in doses between e seven scanners. The most significant difference is noted for CT orax. Fig. 3 on page 8 depicts a fourfold difference in e median value of CTDIvol for CT orax between scanner 3 and 7, which are e same scanners at two different institutions. This indicates e need for protocol optimization and rigorous review of clinical workflow. CT 2 and CT4 are also same scanners at two different institutions, however, in addition to 65% difference in e median doses between e two, CT 4 also shows less variability in doses as compared to CT2. This indicates a more harmonized and standardized dose distribution in e hospital wi CT4. National Benchmarking A local dose registry from e data of e two-year period was created (25 and 75 percentile values listed in Fig. 4 on page 5. Comparison of radiation doses wi published national DRLs for Switzerland (published in 2010) was also carried out (4). Comparison of radiation doses wi published national DRLs for Switzerland (published in 2010) was also carried out (4). Except for CT abdomen-pelvis, e 75 percentile DLP values for our regional registry has lower values as compared to e national DRL of Switzerland for all oer protocols (4). The greatest difference is noted for CT orax, where e DRL (75 percentile) values in our study is 50% lower an national DRL. For CT head, our study shows 18% lower values an national DRL. Fig. 5 on page 8 shows e CTDIvol for CT head by e seven scanners for e two years. All seven scanners have 75 DRL values lower an 65 mgy (e national DRL), e largest value in our registry was 64 mgy. While one scanner had 25 percentile CTDIvol of 45 mgy (same as published national 'target' 25 percentile value), e rest of e six scanners were less an 45 mgy. Such results indicate at e rapid advancements in dose-efficient technology (such as iterative reconstruction) and eir use are rendering e previously published DRLs outdated. There is a need to update e pre-existing registries, especially for CT orax. Also, e previously published DRL's do not prescribe values for e new dose-metric SSDE. Images for is section: Page 4 of 11

5 Fig. 1: Hospital, CT scanner and picture archiving and communication systems (PACS) specifications. Note: SAFIRE: Sinogram affirmed iterative reconstruction, ADMIRE: Advanced model iterative reconstruction. - Riehen/CH Page 5 of 11

6 Fig. 4: 25, 50 and 75 percentile values of CTDIvol (in mgy) and DLP (in mgycm) for all five protocols by e seven CT scanners. - Riehen/CH Page 6 of 11

7 Page 7 of 11

Fig. 2: Summary of 25 and 75 (local DRL) percentile values of e volumetric dose index (CTDIvol), DLP (dose-leng product), SSDE (size-specific dose estimate) and effective dose (ED) for regional CT

8 Fig. 2: Summary of 25 and 75 (local DRL) percentile values of e volumetric dose index (CTDIvol), DLP (dose-leng product), SSDE (size-specific dose estimate) and effective dose (ED) for regional CT dose registry in Nor-Western Switzerland compared to existing Swiss DRL (4). - Riehen/CH Fig. 3: Volumetric CT dose index (CTDIvol) of CT orax by seven different CT scanners. The whiskers represent minimum and maximum values. The blue, yellow and pink ends of e box represent e 25, 50 and 75 quartiles. - Riehen/CH Page 8 of 11

9 Fig. 5: Volumetric CT dose index (CTDIvol) for CT head (by seven different CT scanners. The whiskers represent minimum and maximum values. The blue, yellow and pink ends of e box represent e 25, 50 and 75 quartiles. - Riehen/CH Page 9 of 11

10 Conclusion and Recommendations The cardinal advantage of dose monitoring softwares is e easy near real-time availability of e processed big-data, which was done earlier manually and hence was prone to marked errors. Therefore, guidelines can be made on e basis of a larger sample size which would be representative of e average doses in an institution raer an reflect e 'best case scenario' and reduce variability. Results from our study (wi larger sample size) show at published national DRL are outdated, especially for CT orax and at e currently available dose-reduction techniques appear to be optimal to reinforce in clinical routine. At e inter-institutional level, is data is anonymized and discussed in an objective non-confrontational manner to optimize e process and learn from institutions wi consistently lower doses. There are still a few hurdles for setting up a local registry, e most important of which is lack of standardized nomenclature for protocols. Gradually renaming and standardizing protocols by using established lexicon such as Radlex could address is. Oer challenges remain wi respect to monetary resources, motivation of an institution to provide 'optimal' care and allocated time for carrying out 'dose work'. Normal 0 false false false EN-US JA X-NONE Programmatic radiation dose monitoring using RTS has emerged as a valuable tool to understand, manage and mitigate dose concerns. But e process should have clear justifications, objectives and operational components in order to be efficient and effective. Personal/Organisational information Dr. Schindera is e Director of e dose-team at e University Hospital of Basel and initiated e development of a regional dose-registry by involving e local hospitals in Nor-Western Switzerland. References 1. Brenner DJ, Hricak H. Radiation exposure from medical imaging: time to regulate? JAMA. 2010;304(2): Page 10 of 11

11 2. Aroua A, Samara ET, Bochud FO, Meuli R, Verdun FR. Exposure of e Swiss population to computed tomography. BMC Med Imaging. 2013;13: Langlotz CP. RadLex: a new meod for indexing online educational materials. Radiographics. 2006;26(6): Treier R, Aroua A, Verdun FR, Samara E, Stuessi A, Trueb PR. Patient doses in CT examinations in Switzerland: implementation of national diagnostic reference levels. Radiat Prot Dosimetry. 2010;142(2-4): Page 11 of 11

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

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