International Atomic Energy Agency Impact of Optimization in Newer Technologies Impact of Optimization in Newer Technologies L 8.2

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 2 Educational Objectives 1.What benefit of digital flat panel technology be expected on patient dose 2.How to translate this into practice 3.Experience with optimisation

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 3 Anticipated per-frame dose reduction with Digital Flat Panel technology is 30%

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 4 Motorized Iris Video Camera Image Intensifier DETECTOR Photons Cesium Iodide (CsI) Light Amorphous Silicon Panel (Photodiode/Transistor Array) Digital Data Electrons Read Out Electronics Photons Cesium Iodide (CsI) Light Photo-cathode Video Signal Electrons Output screen Light CCD or PUT Electrons Readout Electronics 1 3, ,000 2,400 Particles #

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 5 diagnostic and interventional activity Udine, years Philips OM 200 (1983) Philips Integris 3000 (1995) performed by 3 interventionalists except in 1998

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 6 Innova 2000 at Udine Center activity started 04/12/2002 Jan.-Oct procedures (79% of total) 1019 diagnostic 402 PCI

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 7 Dose in a plane (or exposure, or air-KERMA) decreases as the inverse square of the distance between this plane and the source (focal spot) The area of the intersection of the beam with a plane increases as the square of the distance between this plane and the source (focal spot) The product of Dose times Area is therefore independent from the distance to the source; This Dose.Area product (DAP) can be measured by an ionization chamber, provided the beam is fully contained by the chamber d1d1 d2d2 d3d3 S3S3 S2S2 S1S1 D1D1 D2D2 D3D Dose Area Product

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 8 comparison of Philips H 3000 and Innova 2000 in PCI characteristics of patients H 3000 : 588 pts, 90% of tot. treated in the year 2002 Innova : 274 pts, 67% of tot. treated between Jan-Oct 2003 diseased vessels (%)

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 9 % comparison of Philips H 3000 and Innova 2000 in PCI characteristics of procedures & lesions (1)

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 10 % comparison of Philips H 3000 and Innova 2000 in PCI characteristics of procedures & lesions (2)

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 11 (m’) comparison of Philips H 3000 and Innova 2000 in PCI performance & complexity indexes 1,37 1 1,47 0,93 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 Comp. Index GISE Index r (with fluoro time) ,611, ,1 21,6 H 3000 Innova

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 12 comparison of Philips H 3000 and Innova 2000 in diagnostic procedures characteristics of patients & procedures H 3000 : 1401 pts, 92% of tot. studied in the year 2002 Innova : 702 pt, 69% of tot. studied between Jan-Oct 2003 (%)

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 13 m’ Gy * cm 2 measured comparison of Philips H 3000 and Innova 2000 in diagnostic procedures performance indexes and exposure parameters calculated Fluoro T proced. T room occ. contrast (dl) cine DAP fluoro DAP tot. DAP 1,3 H 3000 Innova

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 14 why the anticipated 30% per-frame dose reduction of DFP technology does not translates into an effective dose reduction to patients

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 15 differences in operating conditions of the two systems H 3000 field of view (cm) 23/18/14 cine mode 12,5/25 fps fluoro mode low/medium/high filter automatic Innova field of view (cm) 20/17/15/12 cine mode 15/30 fps pref 1/pref 2 (lower dose) fluoro mode low/normal filter manual

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 16 Exact framing (underframing) maximum intensifier output used the smallest image Total overframing intensifier output underused the largest image Maximum horizontal framing compromise in intensifier output compromise in image size Maximum square framing compromise in intensifier output compromise in image size Modified from Green, Lippincott - Raven 1996

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies cm 23 cm 400 cm cm 2

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 18 other possibilities……  patients may not be the same  procedures may not be the same  operators’ behavior filters/collimation use of “difficult” projections (fluoro/cine) focus-detector mean distances  ………

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 19 collimators use in INNOVA to reduce exposure FOV 15 dose reduction 25%

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 20 FOV 20 collimators use in INNOVA to reduce exposure

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 21 proper filtering improper filtering causes image deterioration H 3000

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 22 INNOVA improper filtering does not cause image deterioration

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 23 variation in exposure rate with projection anthropomorphic phantom (average-sized) measurements Cusma JACC 1999

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 24 Distance between patient and detector

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 25 d 2d Because the same energy is spread over a surface 4 times larger at a doubled distance, the same object will receive only a fourth of the dose when moved away from “d” to “2d” Source Doubling the distance from the source divides the dose by a factor of 4 The inverse square law

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 26 The inverse square law

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 27 Collimation

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 28 Anti-scatter grid

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 29 MD nurse technician 1 staff position in the cath. lab. mobile screens ceiling bed technician 2

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 30 staff neck dose in the cath. lab. 57 procedures procedure  Gy/procedura MD nurse Technician 1 Cathet Cardiovasc Diagn 1997 Cardiologia & Fisica Sanitaria - Udine

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 31 Example of the optimization process Data collection procedures, DAP, fluoro time Data analysis reliability of data Discussion & processes review collimators/filters use, FOV, projections Implementation of changes more precise data collection, collimators/filters use, FOV 17 whenever possible, avoiding LAO projections Data verification

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 32 Innova Changes in exposure parameters over time diagnostic procedures Jul Feb. 2004

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 33 procedure optimization in the cath. lab. patients and staff share a lot…… correct indications fluoro time reduction frame rate reduction (25 12,5/sec) collimation/filtering LAO cranial projection limitation distance from X rays source protective screen use protective glasses and gloves (staff) (patient)

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 34 PCI optimization comparison of two periods 715 ± ± ± ± % p< p=ns CI=0.65CI=0.58 p=ns Cardiologia & Fisica Sanitaria - Udine

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 35 procedure optimization annual hand dose (cardiologist) - 27% + 2% - 49% - 23% Cardiologia & Fisica Sanitaria - Udine mSv %

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 36 Gy*cm 2 procedure optimization DAP measurements at Udine Hospital (a ll procedures )

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 37 Gy*cm 2 PCI optimization over time

Radiation Protection in Cardiology Lecture 8.2: Impact of optimization in newer technologies 38 closing remarks angiographic procedure optimization is a continuous process of research and audit this must involve Scientific Societies and single operators must be based on co-operation of all professionals involved (cardiologists, physicists, radiologists, technicians)