Clinic based transfer of the N{sub D,w}{sup 6{sup 0Co}} calibration coefficient using a linear accelerator

Journal Article · Sun Mar 15 04:00:00 EDT 2009 · Medical Physics

DOI:https://doi.org/10.1118/1.3075822· OSTI ID:22098467

Abdel-Rahman, W.; Evans, M. D. C.; Serre, L.; McCaffrey, J. P.; Podgorsak, E. B.; Seuntjens, J. P. ^[1]

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1. Department of Medical Physics, McGill University Health Centre, 1650 Avenue Cedar, Montreal, Quebec H3G 1A4 (Canada)

Ionization chambers used for reference dosimetry require a local secondary standard ionization chamber with a {sup 60}Co absorbed dose to water calibration coefficient N{sub D,w}{sup 6{sup 0Co}} traceable to a national primary standards dosimetry laboratory or an accredited secondary dosimetry calibration laboratory. Clinic based (in-house) transfer of this coefficient to tertiary reference ionization chambers has traditionally been accomplished with chamber cross calibration in water using a {sup 60}Co beam; however, access to {sup 60}Co teletherapy machines has become increasingly limited for clinic based physicists. In this work, the accuracy of alternative methods of transferring the N{sub D,w}{sup 6{sup 0Co}} calibration coefficient using 6 and 18 MV photon beams from a linear accelerator in lieu of {sup 60}Co has been investigated for five different setups and four commonly used chamber types.

• OSTI ID: 22098467
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 3 Vol. 36; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
61 RADIATION PROTECTION AND DOSIMETRY
ACCURACY
CALIBRATION
COBALT
COBALT 60
DOSIMETRY
IONIZATION CHAMBERS
LINEAR ACCELERATORS
PHOTON BEAMS
RADIOTHERAPY