Dose area product evaluations with Gafchromic^®XR-R films and a flat-bed scanner

Abstract

Gafchromic XR-R films are a useful tool to evaluate entrance skin dose in interventional radiology. Another dosimetric quantity of interest in diagnostic and interventional radiology is the dose area product (DAP). In this study, a method to evaluate DAP using Gafchromic XR-R films and a flat-bed scanner was developed and tested. Film samples were exposed to an x-ray beam of 80 kVp over a dose range of 0-10 Gy. DAP measurements with films were obtained from the digitalization of a film sample positioned over the x-ray beam window during the exposure. DAP values obtained with this method were compared for 23 cardiological interventional procedures with DAP values displayed by the equipment. The overall one-sigma dose measurement uncertainty depended on the absorbed dose, with values below 6% for doses above 1 Gy. A maximum discrepancy of 16% was found, which is of the order of the differences in the DAP measurements that may occur with different calibration procedures. Based on the results presented, after an accurate calibration procedure and a thorough inspection of the relationship between the actual dose and the direct measured quantity (net optical density or net pixel value variation), Gafchromic XR-R films can be used to assess the DAP.

Calibration of GafChromic XR‐RV3 radiochromic film for skin dose measurement using standardized x‐ray spectra and a commercial flatbed scanner

“…19 As per ISP recommendations, as well as the successful results of other researchers, the calibration films were scanned with an Epson Expression 10000XL flatbed document scanner 24Ϯ 4 h postexposure. 19,[21][22][23][24][25]33,36 The postexposure time dependence of film darkening was also evaluated. The software package "EPSON SCAN" ͑Version 3.04A͒ was used to control the scan parameters, which included scanning in "Professional Mode," reflective mode, with all imaging adjustment options turned off, and with a resolution of 72 dpi.…”

“…19 Film calibration and film-property measurements have been performed for several versions of fluoroscopic energy-range radiochromic film ͑e.g., GafChromic ® MD-55, XR-R, and XR-RV2 films͒. [19][20][21][22][23][24][25] This work examines the response of a newly formulated radiochromic film ͑GafChromic ® XR-RV3͒ to four National Institute of Standards and Technology ͑NIST͒ traceable, moderately filtered x-ray beams in the energy range of 60-120 kVp, similar to beam qualities used for interventional procedures. The calibration of a commercial flatbed scanner for the digitization of radiochromic films is also reported.…”

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

“…Among the multiple fit functions tested in this study, exponential equations 17,19 were found to be inappropriate for XR-RV3 film calibrations. Errors on the high dose values generally exceeding 40% were obtained with these functions since the film response with dose does not show exponential behavior (cf.…”

Dose distribution in pediatric CT head examination using a new phantom with radiochromic film

“…The CT dose phantom has been designed to measure the CT dose index (CTDI) 16,17 , the CDTI variations (CTDIw and CTDIvol), and the dose-length product (DLP) 17 using a pencil-type ionization chamber. There are two types of CT dose phantoms, a body phantom (32 cm) and a head phantom (16 cm) 16,18,19 .…”

“…There are two types of CT dose phantoms, a body phantom (32 cm) and a head phantom (16 cm) 16,18,19 . Each phantom has five probe holes with inside diameter 1.31 cm to insert a penciltype ionization chamber.…”