title: Characterization of a gated fiber-optic-coupled detector for application in clinical electron beam dosimetry.
abstract: OBJECTIVE
  Assessment of the fundamental dosimetric characteristics of a novel gated fiber-optic-coupled dosimetry system for clinical electron beam irradiation.
  
  
  METHODS
  The response of fiber-optic-coupled dosimetry system to clinical electron beam, with nominal energy range of 6-20 MeV, was evaluated for reproducibility, linearity, and output dependence on dose rate, dose per pulse, energy, and field size. The validity of the detector system's response was assessed in correspondence with a reference ionization chamber.
  
  
  RESULTS
  The fiber-optic-coupled dosimetry system showed little dependence to dose rate variations (coefficient of variation +/- 0.37%) and dose per pulse changes (with 0.54% of reference chamber measurements). The reproducibility of the system was +/- 0.55% for dose fractions of approximately 100 cGy. Energy dependence was within +/- 1.67% relative to the reference ionization chamber for the 6-20 MeV nominal electron beam energy range. The system exhibited excellent linear response (R2 = 1.000) compared to reference ionization chamber in the dose range of 1-1000 cGy. The output factors were within +/- 0.54% of the corresponding reference ionization chamber measurements.
  
  
  CONCLUSIONS
  The dosimetric properties of the gated fiber-optic-coupled dosimetry system compare favorably to the corresponding reference ionization chamber measurements and show considerable potential for applications in clinical electron beam radiotherapy.
authors: Department of Radiation Medicine, Oregon Health and Science University, Portland, Oregon 97239, USA. tanyij@ohsu.edu
authors: James A
authors: JA
authors: Tanyi
authors: Kevin D
authors: KD
authors: Nitzling
authors: Camille J
authors: CJ
authors: Lodwick
authors: Alan L
authors: AL
authors: Huston
authors: Brian L
authors: BL
authors: Justus
mesh_terms: D004583:Electrons / Q000627:therapeutic use*; D016014:Linear Models; D055100:Optical Fibers; D011874:Radiometry / Q000295:instrumentation*; D011878:Radiotherapy; D011879:Radiotherapy Dosage; D015203:Reproducibility of Results