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 EDR2 film is the new addition to Kodak’s award winning family of products designed specifically for oncology applications. Compared to most x-ray films, it is relatively insensitive to x-ray energies and, hence, has a response which extends to very high exposures. Intended for direct exposure applications. It is not suitable for portal imaging radiographs.
EDR2 Features:
• Film is a convenient means of calibration and monitoring of exposures
• Large area
• Low cost, widely available
• Excellent for relative dosimetry (e.g., field uniformity, equipment characterization: field shapes, port openings, MLCs)
• With appropriate calibration, film may be applicable to absolute dosimetry (e.g., high-dose treatment strategies such as IMRT
Features of EDR2 direct exposure applications:
• Wide response range
• Approximately linear
• Robust processing
Dose Response for Evaluation
Exact dose responses are a function of facility dependent factors including processing conditions (processing time, processing temperature, processing equipment, processing chemistry), the density sampling (digitizer equipment and calibration), and exposure monitoring equipment. The exact response relationship should be measured and verified for the local conditions. The films should be processed using recommendations found in Kodak Service Bulletin #30 (refer to EC film guidelines).
Measurement Technique
The dose response of a film should be measured using appropriate amounts of build-up and backscatter material. Many references have discussed methodology for measuring the response of a film. A few of these are:
M.D.C. Evans and L.J. Schreiner, “A simple technique for film dosimetry,” Radiotherapy. Oncol. Vol 23, pages 265-267, 1992.
J. I. Hale, A. T. Kerr, and P. C. Shragge, “Calibration of film for accurate megavoltage photon dosimetry,” Med. Dosimetry Vol 19, pages 43-46, 1994.
Inhwan J. Yeo, C-K Chris Wang, and Sandra E. Burch, “A filtration method for improving film dosimetry in photon radiation therapy,” Medical Physics Vol 24, pages 1943-1953, December 1997.
J. L. Robar and B. G. Clark, “The use of radiographic film for linear accelerator stereotactic radiosurgical dosimetry,” Medical Physics Vol 26, pages 2144-2150, 1999.
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