2018/7/31. Primary Objective

Transcription

1 Andrew Kuhls-Gilcrist, PhD, DABR July 31, 2018 Primary Objective The purpose of this session is to allow vendors to present their solutions and describe how their product can empower the clinician and supporting staff to make more informed decisions relating to dose management towards minimization of risk during fluoroscopy guided procedures. Risks of Ionizing Radiation > 10 Gy Severe Permanent 5 10 Gy Moderate Prolonged 2 5 Gy Mild Temporary < 2 Gy None Hall EJ, Lessons we have learned from our children: cancer risks from diagnostic radiology, Pediatr Radiol 32(10) (2002) NCRP Report No. 168, Radiation Dose Management for Fluoroscopically-Guided Interventional Medical Procedures 1

2 Dose Metrics Detector Exposure ngy (Drives AERC) Organ Dose / Effective Dose msv (Patient Dose) Peak Skin Dose (PSD) mgy (Patient Dose) Air Kerma at Reference Point* - mgy (Machine Output) Kerma Area Product (KAP) Gy cm 2 (Machine Output) Detector * Patient Entrance Reference Point = 15cm From Isocenter Towards Focus (IEC Standard) Inverse Square Law: 60 cm vs 65 cm = 20% X-ray Tube *21CFR Mandatory for Fluoroscopic Equipment after 6/10/2006; Accuracy Tolerance: ± 35% What s Missing? No Source-to-Skin Distance Corrections No Spatial Information (All Dose Summed as if it Occurred at a Single Point in Space; No C-Arm Angulation or Table Movement) Compared to Fluoro Time: Individual Variability Reduced to a Factor of ~2x Dose to Air, Not Dose to Tissue (No Patient Support Attenuation/Scatter, Tissue Absorption Factor, Backscatter) K.A. Fetterly, X-ray fluoroscopy imaging in the invasive cardiac laboratory 2013 AAPM Spring Clinical Meeting D.L. Miller et al, Radiation Doses in Interventional Radiology Procedures: The RAD-IR Study Part II: Skin Dose, JVIR 2003 Transition Towards Meaningful Dose Information Reference Air Kerma (Dose To Air at Reference Location) Real-Time Patient Dose Tracking System (DTS) (Estimated Skin Dose on Patient Graphic) 2

3 DTS How It Works System Information: kvp, ma, ms, frame rate, field of view, collimator position, beam filter, acquisition mode, AKR Position Information: c-arm angulation, table position, source to image distance Other Considerations: Patient support attenuation/scatter, tissue absorption factor, backscatter DTS VALIDATION DTS VALIDATION EXAMPLE RESULTS* *VK Rana et al, A tracking system to calculate patient skin dose in real-time during neurointerventional procedures using a biplane x-ray imaging system, Med Phys 43(9), (2016) *Bednarek et al., Verification of the performance accuracy of a real-time skin-dose tracking system for interventional fluoroscopy procedures SPIE (2011) *Vano E et al., Experience with a real time patient skin dose distribution estimator for interventional radiology, ECR /ecr2017/C-0774 (2017) 3

4 DTS PATIENT MODELS AND POSITIONING *Skin dose to arms is of secondary value due to smaller body part thickness and variability in position on patient support. DTS BIPLANE CONFIGURATIONS DTS BODY VERSUS HEAD Body Backscatter Factor Head Backscatter Factor ( ) 4

5 DTS REAL-TIME 14 DTS REPORTING Local Storage of Last 500 Reports (2D and 3D Maps) Export to: USB; Windows Networked Drive; External Server via FTP 5

6 Deterministic Effect A CASE REPORT 46 Year Old Male FGI: Cerebral angio with transvenous coil and glue embolization Procedure Time: 150 minutes Exposure Time: 67 minutes Peak Skin Dose: 2.9 Gy Two weeks: nonscarring alopecia Four months: complete hair regrowth Ounsakul V et al, Radiation-Induced Alopecia after Endovascular Embolization under Fluoroscopy, Case Reports in Dermatological Medicine, Article ID (2016) Dose Management DURING A PROCEDURE 6 months pre / post DTS display in exam room 16 operators free to choose all imaging parameters 1,077 consecutive procedures Procedures exceeding 3 Gy Control 2.7% DTS 0.7% *Miller DL et al, Patient radiation doses in interventional cardiology in the U.S.: Advisory data sets and possible initial values for U.S. reference levels, Med Phys 39(10), (2012) Wilson SM et al, Real-time colour pictorial radiation monitoring during coronary angiography: effect on patient peak skin dose and total dose during coronary angiography, EuroIntervention, 12, e939-e947 (2016) Dose Management DURING A PROCEDURE 5 months pre / post DTS display in exam room Single operator 323 consecutive procedures -30% *Miller DL et al, Patient radiation doses in interventional cardiology in the U.S.: Advisory data sets and possible initial values for U.S. reference levels, Med Phys 39(10), (2012) Ichimoto E et al, Efficacy of radiation dose reduction due to real-time monitoring and visualization of peak skin dose during coronary angiography and PCI, Catheter Cardiovasc Interv. 91(4), (2018) 6

7 Dose Management DURING A PROCEDURE Fluoro Time: 30 min Air Kerma: 2,910 mgy Peak Skin Dose: 1,680 mgy Fluoro Time: 29 min Air Kerma: 2,980 mgy Peak Skin Dose: 1,150 mgy Area of overlap avoided by utilization of collimation State of Practice: 1 in 5 Exceed Threshold Dose Study Population: <1 in 100 Exceed Threshold Dose *VL WP, Infinix-i Dose Tracking System: Patient Skin Dose Estimates in Real Time, (2017) DoseRite SUMMARY 36 DOSE MODES GRID PULSE DTS DYNAMIC TRACE SPOT ROI AIP LIVE ZOOM AUTO BEAM FLUORO STORE VIRTUAL ROI LOW DOSE 3D RDSR VARIABLE ISOCENTER 16-BIT ROTATING FPD 100kW TUBE 7:30AM, TH-AB-205-1, Advancements in Radiation Dose Monitoring and Management For over 100 years, the Canon Medical Systems `Made for Life philosophy prevails as our ongoing commitment to humanity. Generations of inherited passion creates a legacy of medical innovation and service that continues to evolve as we do. By engaging the brilliant minds of many, we continue to set the benchmark, because we believe quality of life should be a given, not the exception. 7