Alanine/EPR dosimetry in brachytherapy

Phys Med Biol. 1999 May;44(5):1181-91. doi: 10.1088/0031-9155/44/5/007.

Abstract

The paper reports the experimental procedure adopted to determine the absorbed dose rate in water per reference air kerma rate, D(Kr), (d, theta), along the transverse bisector axis of a 137Cs brachytherapy source. The dose rate measurements have been carried out at difference distances, d, from the source using alanine dosemeters in a water phantom. The reference air kerma rate, Kr, was determined adopting a 'direct procedure' that uses a spherical ionization chamber in air. The dose rate constant of the source examined was D(Kr) (1, pi/2) = 0.99 +/- 0.03 cGy h(-1) (microGy h(-1))(-1). The values of the radial dose function along the transverse axis, g(d), determined with an uncertainty of 3.4% (1sigma), were found to be in good agreement with the results reported in the literature. The uncertainty in dose rate value has been estimated as 2.8% (1sigma) for distances from the source up to 7 cm. Kr has been determined with 1.2% (1sigma) uncertainty. So D(r) (d, pi/2) values were determined with 3% (1sigma) uncertainty.

MeSH terms

  • Alanine
  • Biophysical Phenomena
  • Biophysics
  • Brachytherapy*
  • Cesium Radioisotopes / therapeutic use
  • Electron Spin Resonance Spectroscopy
  • Evaluation Studies as Topic
  • Humans
  • Phantoms, Imaging
  • Radiometry / instrumentation
  • Radiometry / methods*
  • Radiometry / statistics & numerical data
  • Radiotherapy Dosage
  • Water

Substances

  • Cesium Radioisotopes
  • Water
  • Alanine