MEASURING PEAK SKIN DOSE

John H. O’ConnellAdela Salame-Alfie, Ph.D.

NYSDOHDavid F. Lewis, Ph.D.

Poppy Pattanayak

International Specialty Products

THE NEW YORK STATE DEPARTMENT OF HEALTH BEGAN TO MEASURE PATIENTENTRANCE SKIN EXPOSURE DURINGINTERVENTIONAL CARDIOLOGY PROCEDURESSEVERAL YEARS AGO

OUR INITIAL MEASUREMENTS WERE PERFORMED USING TLD’S MOUNTEDON PLASTIC STRIPS

THE RESULTS WERE SPORADIC SINCE WEDID NOT HAVE THE ABILITY TO COMPLETELY COVER THE PATIENT’S BACK WITH TLD’S.

BEFORE BEGINNING THIS STUDY A PROTOCOL WAS DEVELOPED ANDAPPROVED BY THE DEPARTMENT’SINSTITUTIONAL REVIEW BOARD

EACH PARTICIPATING HOSPITAL HAS USED OUR IRB APPROVAL TO SECURE AN EXPEDITED REVIEW FROM THEIR INTERNAL IRB

EACH PATIENT IS GIVEN AN INFORMED CONSENT

DR. LEWIS FROM INTERNATIONALSPECIALTY PRODUCTS COLLABORATEDWITH US TO PROVIDE A METHOD TOSURVEY THE ACTUAL PEAK SKIN DOSE

THE DOSIMETRY WAS PERFORMED USING A WIDE-AREA FILM DOSIMETER CALLEDGAFCHROMIC® XR FILM

80 MEASUREMENTS HAVE NOW BEEN PERFORMED WITH ANOTHER 40CURRENTLY UNDERWAY.

THE FILM DOSIMETER PROVIDES A DOSEDISTRIBUTION OR MAPPING FORMAT THAT WOULD NOT BE AVAILABLE WHEN UTILIZING TLD’S ALONE

FOR THE PATIENTS WHO HAVE BEENSTUDIED SO FAR, THE MINIMUM DOSEMEASUREMENT HAS BEEN ABOUT 150 RADS WITH A MAXIMUM OF 700 RADS

100 Rads

200 Rads 700 Rads

400 Rads

Peak Skin Dose: Comparison of Measurement with GAFCHROMIC XR film vs.

Estimate with DAP

ProcedureFluoro

Time, minSkin Dose from

Film, mGySkin Dose Estimate

from DAP, mGy Error in DAP Measurement

Biliary Stent 16.8 2050 1380 49%

EP/RF Ablation 7.7 700 500 40%

PTCA/CPP 32.3 1800 605 198%

PTCA/Stent LAD 9.9 500 281 78%

R+L Cath/ BiPlane 19.0 250 267 -6%

Biventricular PPM 48.0 3180 1460 118%

Catheterization with graft 11.2 200 762 -74%

Catheterization with 4 grafts 9.1 600 619 -3%

UAE 42.5 7000 3490 101%

TIPPS 53.9 4600 4430 4%

Skin dose can only be estimated from DAP values

DAP seriously under estimates the max peak skin dose

Error in DAP Measurement

49%

40%

198%

78%

-6%

118%

-74%

-3%

101%

4%

GAFCHROMIC XR Type R

Details the dose distribution

Immediate visualization of patient exposure – magnitude and location

GAFCHROMIC XR Type R film - a simple tool for comprehensive monitoring of patient exposure and physician training

L

R

A picture is worth a thousand words

GAFCHROMIC XR Type R film - a simple tool for comprehensive monitoring of patient exposure and physician training

L

R

Raises physicians’ awareness

Know where to treat a latent skin injury

Define where to avoid exposure in future procedures

WE BELIEVE THAT DOSE MEASUREMENTS FOR PATIENTS UNDERGOING INTERVENTIONALPROCEDURES IS AN AREA THAT NEEDS TO BE LOOKED AT FURTHER

WE ENCOURAGE ALL FACILITIES TOESTABLISH THRESHOLDS FOR INTER-VENTIONAL PROCEDURES SO THAT, IF THETHRESHOLD IS EXCEEDED IN TERMS OF FLUOROSCOPY TIME AND/OR IMAGING RUNS,THAT PATIENT WILL BE MONITORED POST-PROCEDURE FOR THE EFFECTS OF IONIZING RADIATION

THANK YOU

NYSDOH