Evaluation of Occupational Dose Reduction in Interventional Radiology Using Lead-Free Protection Drape Poster No.: C-0551 Congress: ECR 2015 Type: Authors: Keywords: DOI: Scientific Exhibit N. K. Taharim, C. H. Yeong, K. H. Ng, B. J. J. Abdullah; Kuala Lumpur/MY Radioprotection / Radiation dose, Interventional vascular, Fluoroscopy, Radiation safety, Occupational / Environmental hazards 10.1594/ecr2015/C-0551 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. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 13
Aims and objectives Occupational radiation dose in interventional radiology (IR) has become a concern due to increasing complexity of the procedures and fluoroscopic time [1, 2]. A lead free protection drape (RadPad Worldwide Innovations & Technologies, USA) has been introduced to absorb scattered radiation by 50 to 95% at 90 kvp during IR procedures. This study aimed to investigate physical characteristics and efficiency of the protection drape in reducing scattered dose to the personnel, in comparison to lead shields. Methods and materials 1. Physical characterization ofradpad Attenuation properties RadPad placed on a 20cm thick Perspex 2 calibrated semiconductor detectors each placed before and afterradpad (Figure 1) X-Ray energy varied 2 types ofradpad studied: Orange (90% attenuation) and Yellow (75% attenuation) RadPad then replaced with 0.25 mmpb-equiv. apron for comparison Evaluation of backscatter properties Ion chamber placed on a 20cm thick Perspex (Figure 2) Exposure made with and withoutradpad placed above the ion chamber Percentage of backscatter radiation was shown and calculated in increase in dose whenradpad was used Dose profiles before and after attenuation by RadPad Radiochromic films sandwiched between sheets of 2cm thick Perspex phantoms (Figure 3) Simulate dose distribution at different depths within the patient body Phantom exposed with 90kVp X-rays at 200mAs Page 2 of 13
Films scanned with a flatbed scanner andanalysed withimagej software 2. Study of scattered radiation dose during fluoroscopy-guided procedure Phantoms used to simulate a radiologist and a patient 3 calibrated electronic personal dosimeters were placed at the brain, thyroid and chest level of the radiologist phantom (Figure 4) Exposure was made using routine fluoroscopy setting (66 kvp,79 ma, AEC mode) for 5,10 and 15 min with Siemens Axiom Artis dfa system. Images for this section: Fig. 1: Set-up to determine dose reduction efficiency Page 3 of 13
Fig. 2: Set-up to determine backscatter properties Page 4 of 13
Fig. 3: Set-up to determine distribution of dose reduction by RadPad Fig. 4: Positioning of patient and radiologist phantom with RadPad placement Page 5 of 13
Results 1. Physical characterization of RadPad Attenuation properties Figures 5 and 6 show the comparison of percentage attenuation and linear attenuation coefficient respectively between RadPad 90%, RadPad 75%, and 0.25mm Pbequivalent. Fig. 5: Comparison of percentage attenuation versus X-Ray Energies Page 6 of 13
Fig. 6: Comparison of linear attenuation coefficient (µ) versus X-Ray energies Evaluation of backscatter properties Percentage of backscattered radiation caused by the interaction of primary beam with the RadPad and 0.25 mm Pb-equiv shield. 0.25 mm Pb-equiv. RadPad 90% RadPad 75% Apron 83.8% 77.9% - Thyroid Shield 86.0% 79.3% - No-Brainer - 70.1% 70.8% Dose profile before and after attenuation by the RadPad Page 7 of 13
Fig. 7: Dose Profile Before RadPad Page 8 of 13
Fig. 8: Dose Profile after RadPad Dose distribution with and without RadPad at different depths within phantom: Page 9 of 13
Fig. 9: Dose Distribution at Varying Depths without RadPad Fig. 10: Dose Distribution at Varying Depths with RadPad Page 10 of 13
2. Study of scattered radiation dose during fluoroscopy-guided procedure Fig. 11: Scattered Radiation to the Thyroid in 5 minutes Fig. 12: Scattered Radiation to the Chest in 5 minutes Page 11 of 13
Results show similar patterns at exposure for 10 and 15 minutes. No scattered radiation was detected at brain level at any distance, and no scattered radiation was detected at distances more than 0.9m. Conclusion RadPad significantly reduces scattered radiation dose to staff during prolonged fluoroscopy-guided procedure RadPad Orange (90% attenuation) provides similar attenuation to 0.25 mmpb-equiv. at 90kVp However, empirical results show deviation from manufacturer specifications (85.8% and 71.6% for Orange and Yellow instead of 90% and 75% at 90kVp respectively) Backscattered radiation detected whenradpad was placed over the phantom, indicating possible increase in patient skin dose. 0.25 mmpbeq. produces higher backscatter radiation compared toradpad, suggesting thatradpad is advantageous in reducing patient skin dose. RadPad has potential as additional radiation shielding, however its lower linear attenuation coefficient compared to lead suggests that it would not be an ideal replacement for lead as the primary personal radiation protection for medical staff. Personal information Prof. Dr. Basri Johan Jeet Abdullah, MBBS, FRCR, MBA Department of Biomedical Imaging University Malaya Dr. Chai Hong Yeong, PhD Department of Biomedical Imaging University Malaya Contact Email: chyeong@um.edu.my Page 12 of 13
Prof. Dr. Ng Kwan Hoong, PhD Department of Biomedical Imaging University Malaya Nurul Khamizah Taharim, MMedPhys Department of Biomedical Imaging University Malaya References 1. Faulkner, K., et al. Practical aspects of radiation protection in interventional radiology. 10th International Congress of the International Radiation Protection Association. 2000. 2. Miller, D.L., et al., Radiation doses in interventional radiology procedures: The RAD-IR study Part II: Skin dose. Journal of vascular and interventional radiology, 2003. 14(8): p. 977-990. 3. Scheneider et al., Reduction of Occupational Exposure to Scatter Radiation During Endovascular Interventions: A Prospective, Placebo Controlled Trial Comparing the Effectiveness of a Disposable Radiation- Absorping Drape, J.Am.Coll.Cardiol. 2010;56;B93, 2010. Page 13 of 13