Characterization of XR‐RV3 GafChromic^® films in standard laboratory and in clinical conditions and means to evaluate uncertainties and reduce errors

Abstract

The overall uncertainty associated with the use of XR-RV3 films to determine skin dose in the interventional environment can realistically be estimated to be around 20% (k = 1). This uncertainty can be reduced to within 5% if carefully monitoring scanner, film, and fitting-related errors or it can easily increase to over 40% if minimal care is not taken. This work demonstrates the importance of appropriate calibration, reading, fitting, and other film-related and scan-related processes, which will help improve the accuracy of skin dose measurements in interventional procedures.

Impact of the calibration conditions of XR-RV3 films on peak skin dose measurements in interventional radiology

“…Calibration is mostly performed according to the manufacturer's recommendations, in air, with the higher dose rate (>1 Gy/min). However, according to Farah et al 18 , dose rate variation does not have influence on film calibration.…”

“…Our study was performed with films white facing towards x-ray source, following ISP 295 recommendation. However, as some groups work using the other side facing the source, it would be interesting to evaluate the orange side facing source 18 . We used our flatbed scanner without uniformity correction.…”

“…However additional filtration was introduced to reduce the amount of low 95 energy photon 17 . Both kVp and total filtration modify the photon spectrum, a recent study showed the importance of choosing the appropriate calibration beam quality in air 18 . Hence, patient follow up depends on the beam quality chosen for the film calibration (energy and filtration).…”

Vendor‐independent skin dose mapping application for interventional radiology and cardiology

“…The film pieces were irradiated to 16 air kerma values between 0 and 10 Gy using RQR8 standard beam quality 29 . The conversion of air kerma to absorbed dose to skin is considered to be equal to one 30 …”

“…Uncertainties related to the use of XR‐RV3 Gafchromic films for patient skin dose assessment in the interventional environment have been estimated in our previous work and published in Medical Physics 30 . It is shown that overall uncertainty of skin dose measurements using XR‐RV3 Gafchromic films ranges from 9% (k = 2) for tightly controlled measurement conditions, adequate laboratory calibrations and well‐defined readout protocol to 78% (k = 2) in the worst case scenario where the conditions of exposure, film handling, and readout are weakly controlled and where corrections for the relevant influence quantities are not made.…”