Managing Patient Fluoroscopy Dose Christopher B Martel CHP

--Headline and photograph accompanying article published in USA Today [2] reporting jury award of $1 million to 57 -year-old man who sustained serious skin injury after two coronary artery angioplasties that occurred 5 months apart Berlin, L. Am. J. Roentgenol. 2001; 177: 21 -25

Radiation Damage to Skin Radiation Dermatitis Radiation damage. There is loss of dermal appendages. Blood vessels are telangiectatic. (H&E)

Fluoroscopy Uses • • • • Anesthesia (Pain management) Urology Otolaryngology (Ear, nose, throat) Orthopedics Interventional Radiology Emergency Room Cardiac Catheterization Electrophysiology Interventional Neuroradiology Radiation Oncology Neurosurgery Surgery Gastroenterology (Endoscopy) Image Intensifier X-Ray Tube

Who is getting involved? • CRCPD – State Regulations – Committee established to develop a list of reportable events (including fluoroscopy) • JCAHO Sentinel Event – Prolonged exposure to single field resulting in >1500 rads • NCRP Report 160 – Number of Interventional fluoroscopy procedures increased eight fold over past 25 years

Typical Regulatory Requirement • Conduct Patient Dose Evaluations • Report patient cumulative doses in single procedure > 1 Gy to Radiation Safety Committee • Dose must be entered into the patient’s medical record • Perform follow up with patients likely to have deterministic injury • Physician must have fluoroscopy priviliges

What’s Important? Peak Skin Dose The likelihood and severity of radiationinduced skin injury to the patient as a whole are functions of the highest radiation dose at any point on that patient’s skin— the PSD.

Interventional Reference Point For C-arm–type fluoroscopic systems with an isocenter, the IRP is located along the central ray of the x-ray beam at a distance of 15 cm from the isocenter in the direction of the focal spot.

Backscatter • Backscattered radiation contributes 2745% to the measurement. C J Martin 1995 Phys. Med. Biol. 40 823 • Backscattered radiation contributes 25 40% to the measurement. S Balter 2010 Radiology 254 326 -341

What methods are currently being used? • • • Time GAFchromic film Dose Mapping Landauer Dots Cumulative Air KERMA

Time • Fluoroscopy time, although still used in many healthcare institutions as an indicator for skin dose, it is widely known that there is little correlation between fluoroscopy time and skin dose.

GAFChromic Film • Measures surface peak skin dose • Sensitive to dose range 1 c. Gy to 10 Gy and energy range 30 Ke. V to 30 Me. V. • Visually identify areas of overlap

Landauer Nanodots • Range is 10 mrad to 1500 rads • +/- 5% • Radiotranslucent

Graphical display of Caregraph (Siemens Medical Solutions) Chida, K. et al. Am. J. Roentgenol. 2006; 186: 774 -778

Cumulative AIR Kerma The air kerma accumulated at a specific point in space relative to the fluoroscopic gantry (the interventional reference point) during a procedure. CD does not include tissue backscatter and is measured in Gy. CD is sometimes referred to as cumulative air kerma. J Vasc Interv Radiol 2004; 15: 423– 429

Which method should you use? • What are you trying to do? • According to ACR: – Identify area to avoid in future procedures – Identify patients likely to develop a radiationinduced skin injury – provide follow up

Brigham & Women’s Hospital (BWH) Fluoro Dose Management Goals – Develop a tool that will facilitate: • Compliance with regulations • Allow monitoring of physician “performance” to guide best practices and identify opportunities for quality improvement • Allow monitoring of procedures to compare with other institutions and published data

BWH Results • Groups that perform fluoroscopically guided procedures with potential to exceed 1 Gray. – Electrophysiology – Cardiac Catheterization – Interventional Radiology – Interventional Neuro-radiology – Neurosurgery

Physician < 1000 m. Gy >1000 m. Gy Patient undergoes fluoroscopic guided procedure No further action required MD notes dose in patient’s medical record Procedure info added to database by MD designee HP < 5, 000 m. Gy Health Physics reviews database daily HP Reports all >1 Gy exposures to RSC in bimonthly report >5, 000 m. Gy > 15, 000 m. Gy MD gives patient discharge instructions No further action required Health Physics sends letter to attending requiring follow up HP notifies Risk Management of potential Sentinel Event Physician schedules follow up visit in 2 to 4 weeks Physician follows up with patient and if injury present provides referral to Dermatology Risk Management reviews and makes determination Patient Fluoroscopy Dose Management and Reporting

Desirable Features for BWH Patient Dose Tracking Program • • • Web-based Secure Editing/tracking Searchable Statistical Analysis Reporting (Inventor of the Internet)

What we are doing • Track ALL fluoro procedures in EP, CC, IR and INR – Cumulative Air Kerma – Fluoroscopy Time – Attending Physician – MRN – Referring Physician

Other Features • • Median dose for every procedure Statistics for each physician by procedure Sum fluoro doses for each patient Record patient dose and follow-up information • Cross referenced with physician credentialing database • Drop down menus tailored to groups based on their log in

Dashboard

By Physician Name Here

By Procedure Physician Names Here

By Multiple Procedures for Individual Patients Patient MRNs Here

Summation of Patient Cumulative Air Kerma MRN Here Physician Names Here

Make notes on cases

Interventional Reference Levels IRL = 75 th Percentile AHD = (1. 5 * IQR) + 75 th Percentile

Looking at the Data • Median CAK for 38 of 39 procedures is below 500 milli. Gray • 75 th percentile of CAK for 36 of 39 procedures is below 1, 000 milli. Gray • Outlier CAK for 34 of 39 is below 2, 000 milligray

Conclusions • For most interventional procedures at BWH, a CAK greater than 2, 000 m. Gy should be rare. Exceptions are: – Percutaneous Coronary Interventions – Device upgrade ICD-CRT – Ventricular Epicardial Ablations

Conclusions (cont) Individual Cases >1 Gray – reported to RSC and noted in EMR >5 Gray – Follow up with patient >15 Gray – Investigation for SE Physician Data Median for procedure > 1 Gray – reported to Dept Chair for evaluation

Conclusions (cont) What gets measured, gets managed! • Over 8, 000 cases in database so far (January 1, 2009 to present) • Developed BWH-specific Interventional Reference Levels (IRLs) • Provide quarterly reports of physician fluoro use to Department Chairs, Chief Medical Officer, individual physicians