Development of a fibre-optic dosemeter to measure the skin dose and percentage depth dose in the build-up region of therapeutic photon beams.

In this study, a fibre-optic dosemeter (FOD) using an organic scintillator with a diameter of 0.5 mm for photon-beam therapy dosimetry was fabricated. The fabricated dosemeter has many advantages, including water equivalence, high spatial resolution, remote sensing and real-time measurement. The scintillating light generated from an organic-dosemeter probe embedded in a solid-water stack phantom is guided to a photomultiplier tube and an electrometer via 20 m of plastic optical fibre. Using this FOD, the skin dose and the percentage depth dose in the build-up region according to the depths of a solid-water stack phantom are measured with 6- and 15-MV photon-beam energies with field sizes of 10 × 10 and 20 × 20 cm(2), respectively. The results are compared with those measured using conventional dosimetry films. It is expected that the proposed FOD can be effectively used in radiotherapy dosimetry for accurate measurement of the skin dose and the depth dose distribution in the build-up region due to its high spatial resolution.

[1]  M. Carolan,et al.  Comparison of the New MOSkin Detector and Fiber Optic Dosimetry System for Radiotherapy , 2008 .

[2]  J. Purdy,et al.  Build-up region of megavoltage photon radiation sources. , 1975, Medical physics.

[3]  A. Dutreix,et al.  Characteristics of contamination electrons in high energy photon beams. , 1993, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[4]  Louis Archambault,et al.  Water-equivalent dosimeter array for small-field external beam radiotherapy. , 2007, Medical physics.

[5]  N. Papanikolaou,et al.  Measurement and comparison of skin dose for prostate and head-and-neck patients treated on various IMRT delivery systems. , 2008, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[6]  F. Khan.  The physics of radiation therapy , 1985 .

[7]  M. Clift,et al.  Dealing with Cerenkov radiation generated in organic scintillator dosimeters by bremsstrahlung beams. , 2000, Physics in medicine and biology.

[8]  F. H. Attix,et al.  Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: I. Physical characteristics and theoretical consideration. , 1992, Physics in medicine and biology.

[9]  Simon Fleming,et al.  Transmission of Čerenkov radiation in optical fibers , 2007 .

[10]  T. Aoyama,et al.  A depth-dose measuring device using a multichannel scintillating fiber array for electron beam therapy. , 1997, Medical physics.

[11]  Variations in skin dose using 6MV or 18MV x-ray beams , 2003, Australasian Physics & Engineering Sciences in Medicine.

[12]  I. Das,et al.  Choice of Radiation Detector in Dosimetry of Stereotactic Radiosurgery-Radiotherapy , 2000 .

[13]  G. Glasgow,et al.  Surface and build-up region dosimetry for obliquely incident intensity modulated radiotherapy 6 MV x rays. , 2003, Medical physics.

[14]  Measurement of radiotherapy superficial X-ray dose under eye shields with radiochromic film. , 2008, Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics.

[15]  M. Butson,et al.  Skin dosimetry with new MOSFET detectors , 2008 .

[16]  Bongsoo Lee,et al.  Characterization of a scintillating fiber-optic dosimeter for photon beam therapy , 2009 .

[17]  Hyosung Cho,et al.  Measurement of two-dimensional photon beam distributions using a fiber-optic radiation sensor for small field radiation therapy , 2008, 2007 IEEE Nuclear Science Symposium Conference Record.

[18]  F. H. Attix,et al.  Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: II. Properties and measurements. , 1992, Physics in medicine and biology.

[19]  J. Seuntjens,et al.  Accurate skin dose measurements using radiochromic film in clinical applications. , 2006, Medical physics.

[20]  J. M. Fontbonne,et al.  Scintillating fiber dosimeter for radiation therapy accelerator , 2001 .

[21]  J M Wilkinson,et al.  Electron contamination and build-up doses in conformal radiotherapy fields. , 1999, Physics in medicine and biology.

[22]  P. Metcalfe,et al.  Measurement of radiotherapy x-ray skin dose on a chest wall phantom. , 2000, Medical physics.

[23]  J. Pouliot,et al.  Miniature scintillating detector for small field radiation therapy. , 1999, Medical physics.

[24]  A. Beddar,et al.  Plastic scintillation dosimetry and its application to radiotherapy , 2006 .

[25]  M. Butson,et al.  TLD extrapolation for skin dose determination in vivo. , 1996, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.