title: Evidence for a significantly higher than expected depth dependence of wedge transmission factors on the 4 MV beam of a new dual energy accelerator.
abstract: Wedge transmission factors have been measured for two sets of physical wedges for the 4 MV beam of a new dual energy linear accelerator as a function of field size and depth. The field size dependence of these factors has been compared with the 4 MV beam from another, single-energy linear accelerator and a difference of a factor of approximately 2 has been observed in the relative wedge transmission factors between the two machines.
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston 02114, USA. biggs@hadron.mgh.harvard.edu
authors.forename: P J
authors.initials: PJ
authors.lastname: Biggs
authors.forename: J
authors.initials: J
authors.lastname: Beatty
authors.forename: J
authors.initials: J
authors.lastname: Radloff
mesh_terms: D009010:Monte Carlo Method; D010315:Particle Accelerators; D019047:Phantoms, Imaging; D011878:Radiotherapy / Q000295:instrumentation* / Q000379:methods; D011879:Radiotherapy Dosage; D014867:Water
chemical_list: D014867:Water