Characteristics of Gafchromic^® XR‐RV2 radiochromic film

Abstract

Gafchromic XR-RV2 is a revised version of the obsolete Gafchromic XR-R-type radiochromic film. This article investigates the dose response, energy response, postexposure growth, and polarizing effects of this film after exposure to ionizing radiation in the diagnostic energy range. The effect of bit depth on scanning was also investigated. Films were scanned using an Epson Expression 10000XL document scanner or an X-Rite model 301 spot densitometer. Color channel analysis was performed. The film showed usable response in the air kerma range of 1-1000 cGy, although by 1500 cGy the film appeared saturated when using the red color channel on a document scanner. The film response varied by 11% between 60 and 96 kVp and 3.5% between 96 and 125 kVp for doses above 1 Gy. Postexposure growth was found to be approximately logarithmic and fairly stable after 24 h. Films stored under office lighting exhibited around twice the density growth compared with film stored in a dark environment. The film showed strong orientation dependence when scanned using a polarized light source. A 48 bit scan provided no increase in sensitivity over 24 bits. Gafchromic XR-RV2 film is a radiochromic film ideally suited for measurement of wide dose ranges at diagnostic energies. The energy dependence of this film limits its accuracy for dosimetry of unknown energy beams. For the document scanners used in this study a 24 bit scan was more than sufficient compared to a 48 bit scan. This is likely to be the case for most document scanners where electrical noise prevents higher bit depths from increasing the sensitivity of measurements.

Comparison of indirect radiation dose estimates with directly measured radiation dose for patients and operators during complex endovascular procedures

“…Given the large film size and wide energy response, this method is considered to be the most reliable way to record the entrance radiation dose distribution during interventional procedures. 6,7 This resulted in total coverage of the thoracoabdominal region and ability to detect any exposure with the exception of a perfectly lateral (90°) C-arm angle. The X-ray film was removed postprocedure and allowed to stabilize for at least 48 hours before analysis.…”

“…The X-ray film was removed postprocedure and allowed to stabilize for at least 48 hours before analysis. 6 A calibration strip of Gafchromic film was created for each lot of film used in a range of absorbed doses between 0.5 Gray (Gy) and 12.5 Gy using methods recommended by the manufacturer. Each patient's X-ray film along with the associated calibration strip was scanned using an Epson Expression 10000 XL (Epson, San Jose, Calif) at 48-bit depth and 50-dpi resolution.…”

Radiochromic film dosimetry: Past, present, and future

“…Radiochromic films have been studied [62] and successfully employed to measure dose within diagnostic energy range during diagnostic CT scans [63], CBCT acquisitions [64], and interventional radiology procedures [65]. Figure 7h represents dose profiles measured with XR-QA GAFCHROMICä film strips laced between humanoid Rando phantom sections within pelvic region during CBCT image acquisition, commonly employed n he course of Image Guided Radiotherapy (IGRT).…”

A tracking system to calculate patient skin dose in real‐time during neurointerventional procedures using a biplane x‐ray imaging system

“…19 All films were exposed and scanned in the same orientation, so as to minimize the error due to the polarization effect of the film. 20,21 A calibration curve was acquired by plotting the dose versus the respective red channel values 22 and fitting the data with a fourth degree polynomial equation which had an r 2 value of 0.997 48.…”