GAFChromic Film, EBT4, 8"x10" (25/box)

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GAFChromic Film, EBT4, 8"x10" (25/box)

Gafchromic™ EBT4 is designed for the measurement of absorbed doses of ionizing radiation. It is particularly suited for high-energy photons. The dynamic range of this film is designed for best performance in the dose range from 0.2 to 10 Gy, making it suitable for many applications in IMRT, VMAT and brachytherapy. For measurement of doses substantially greater than 10 Gy EBTXD or MD-V3 are preferred while the use of HD-V2 is indicated for still higher dose measurement.

Use: Patient QA: IMRT, VMAT, brachytherapy

Machine QA: Star Shot test, Picket Fence test, Flatness and Symmetry test

Recommended Dose Range: 0.2 Gy to 10 cGY

Recommended Energy Range: 100keV into the MV range

Structure: The film is comprised of an active layer, nominally 28 µm thick, situated between two 125 µm matte-polyester substrates. The active layer contains the active component, a marker dye, stabilizers and other components giving the film its near energy-independent response. The thickness of the active layer will vary slightly between different production lots.

Key technical features of Gafchromic™ EBT4 include:

 • Optimum dose range: 0.2 Gy to 10 Gy, best suited for applications such as IMRT and VMAT

 • Develops in real time without post-exposure treatment

 • Energy-dependence: minimal response difference from 100 keV into the MV range

 • Near tissue equivalent •high spatial resolution - can resolve features down to 25 µm, or less

 • Proprietary new technology incorporating a marker dye in the active layer

 - Enables non-uniformity correction by using multi-channel dosimetry

 - Decreases UV/visible light sensitivity

 • Stable at temperatures up to 60°C (140°F)

The yellow marker dye incorporated in EBT4, in conjunction with an RGB film scanner and FilmQAPro software,1-3 enables the dosimetry process to benefit from the application of triple-channel dosimetry.

Specifications Gafchromic™ EBT4 film

Configuration: active layer (28 µm) situated between 125 µm matte-surface polyester substrates

Size: 8” x 10” or 13" x 17"

Optimum dose range: 0.2 Gy to 10 Gy

Energy Dependency: <5% difference in net optical density for a single 25 Gy dose and five cumulative 5 Gy doses at 30 min intervals

Dose rate response: <5% difference in net optical density for 10 Gy exposures at rates of 3.4 Gy/min and 0.034 Gy/min

Stability in light: <5 x 10–3 change in optical density per 1000 lux-day

Stability in dark (pre-exposure stability): <5 x 10–4 optical density change/day at 23 °C (74°F) and <2 x 10–4 density change/day refrigerated

Uniformity: better than ±3% in sensitometric response from mean; dose uniformity better than ±2% with FilmQAPro™ and triple-channel dosimetry

Like all other Gafchromic™ films, EBT4 dosimetry film can be handled in interior room light for short periods without noticeable effects. However, it is suggested that the film should not be left exposed to room light for hours, but rather should be kept in the dark when not in use. When the active component in EBT4 film is exposed to radiation, it reacts to form a blue colored polymer with absorption maxima at approximately 633 nm.

Gafchromic™ EBT4 dosimetry film is recommended to be used with a 48-bit (16-bit per channel) flatbed color scanner. The EPSON Expression 12000XL Photo scanner, and the now discontinued models 11000XL Photo and 10000XL Photo scanner are the recommended models. These are color scanners that measure the red, green and blue color components of light transmitted by the film at a color depth of 16 bit per channel. These EPSON scanners are particularly recommended due to their large scanning area.

References

1. Micke, A., Lewis, D.F., Yu, X. “Multichannel film dosimetry with nonuniformity correction,” Med Phys, 38(5), 2523-2534 (2011).

2. Lewis D., Micke A., Yu X, Chan M.: “An Efficient Protocol for Radiochromic Film Dosimetry combining Calibration and Measurement in a Single Scan,” Medical Physics, 39 (10) 6339(2012)

3. An Efficient Calibration Protocol for Radiochromic Film, April 2011 available at https://www.ashland.com/industries/medical/filmqa-prosoftware