AbstractID: 7949 Title: Radiation Dose Measurement in Fluoroscopically-Guided
Intervention Based on Real-Time Dose-Area Products and Portal Film Dosimetry
Purpose: With increasing use of lengthy procedures in fluoroscopy, skin dose
measurement is desirable for monitoring patient exposure and avoiding potential skin
injury. Our institution has recently acquired x-ray machines capable of real-time dose
display, enabling us to evaluate results from these units as compared with those from a
portal film technique we previously reported.
Methods: Real time displays were obtained from Philips (Interventional Radiology) and
Siemens (Cardiology) X-ray systems. Only the latter provided dose-rate, dose-area
products, and dose distribution plot. Films used were Kodak X-Omit V, EC films, and a
new Radiochromic film ISP XR-R, calibrated for doses up to 50, 150, and 800 cGy,
respectively.
Results: Real time display was informative of dose-rates and cumulative dose during the
procedure. It had no (Philips) or only a crude (Siemens) estimate of actual dose
distribution. Film dosimetry gave total and detailed dose distribution for the procedure.
The two approaches served to complement each other well. We analyzed over 200
consecutive procedures in interventional radiology, angioplasty, and EP Lab ablations by
both methods. Results helped us to establish patterns for each given machine applied to
given procedures. This offered prediction of approximate actual doses from real time
readings, confirmable by portal film after completion of the procedure. Over 20% of
studied cases had patient skin doses reaching 200 cGy or higher, some as high as 500
cGy, underscoring the need for routine monitoring.
Conclusion: Real time display and film dosimetry are mutually complementary
methods, warranting adoption for routine use.