Characterization of commercial MOSFET detectors and their feasibility for in-vivo HDR brachytherapy.

AIM The present study was to investigate the use of MOSFET as an vivo dosimeter for the application of Ir-192 HDR brachytherapy treatments. MATERIAL AND METHODS MOSFET was characterized for dose linearity in the range of 50-1000 cGy, depth dose dependence from 2 to 7 cm, angular dependence. Signal fading was checked for two weeks. RESULT AND DISCUSSION Dose linearity was found to be within 2% in the dose range (50-1000 cGy). The response varied within 8.07% for detector-source distance of 2-7 cm. The response of MOSFET with the epoxy side facing the source (0 degree) is the highest and the lowest response was observed at 90 and 270 degrees. Signal was stable during the study period. CONCLUSION The detector showed high dose linearity and insignificant fading. But due to angular and depth dependence, care should be taken and corrections must be applied for clinical dosimetry.

[1]  J. Lambert,et al.  In vivo dosimeters for HDR brachytherapy: a comparison of a diamond detector, MOSFET, TLD, and scintillation detector. , 2007, Medical physics.

[2]  D. Georg,et al.  In-vivo dosimetry for gynaecological brachytherapy: physical and clinical considerations. , 2005, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[3]  R. Ramani,et al.  Clinical dosimetry using MOSFETs. , 1997, International journal of radiation oncology, biology, physics.

[4]  M. Kortesniemi,et al.  Characterization of MOSFET dosimeter angular dependence in three rotational axes measured free-in-air and in soft-tissue equivalent material , 2013, Journal of radiation research.

[5]  Kari Tanderup,et al.  In vivo dosimetry in brachytherapy. , 2013, Medical physics.

[6]  M. McEwen,et al.  Characterization of the phantom material virtual water in high-energy photon and electron beams. , 2006, Medical physics.

[7]  D Baltas,et al.  In vivo thermoluminescence dosimetry dose verification of transperineal 192Ir high-dose-rate brachytherapy using CT-based planning for the treatment of prostate cancer. , 2003, International journal of radiation oncology, biology, physics.

[8]  MOSFET detectors as a tool for the verification of therapeutic doses of electron beams in radiotherapy , 2005 .

[9]  A. Gopiraj,et al.  Performance characteristics and commissioning of MOSFET as an in-vivo dosimeter for high energy photon external beam radiation therapy , 2008 .

[10]  Anatoly Rosenfeld,et al.  Verification of the plan dosimetry for high dose rate brachytherapy using metal-oxide-semiconductor field effect transistor detectors. , 2007, Medical physics.

[11]  Tomas Kron,et al.  An in vivo investigative protocol for HDR prostate brachytherapy using urethral and rectal thermoluminescence dosimetry. , 2009, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[12]  G. Shani,et al.  Application of spherical micro diodes for brachytherapy dosimetry , 2011 .

[13]  S. Marcié,et al.  In vivo measurements with MOSFET detectors in oropharynx and nasopharynx intensity-modulated radiation therapy. , 2005, International journal of radiation oncology, biology, physics.

[14]  J Cygler,et al.  Evaluation of a dual bias dual metal oxide-silicon semiconductor field effect transistor detector as radiation dosimeter. , 1994, Medical physics.

[15]  S. Sharma,et al.  Characteristics of mobile MOSFET dosimetry system for megavoltage photon beams , 2014, Journal of medical physics.

[16]  P. Aruna,et al.  Characterization of responses and comparison of calibration factor for commercial MOSFET detectors. , 2005, Medical dosimetry : official journal of the American Association of Medical Dosimetrists.

[17]  A. Rosenfeld,et al.  A real-time in vivo dosimetric verification method for high-dose rate intracavitary brachytherapy of nasopharyngeal carcinoma. , 2012, Medical physics.

[18]  Ria Bogaerts,et al.  Practical guidelines for the implementation of in vivo dosimetry with diodes in external radiotherapy with photon beams (entrance dose) , 2001 .

[19]  J. Dam,et al.  METHODS FOR IN VIVO DOSIMETRY IN EXTERNAL RADIOTHERAPY , 2005 .

[20]  J. Bucci,et al.  The effect of rectal heterogeneity on wall dose in high dose rate brachytherapy. , 2008, Medical Physics (Lancaster).

[21]  R Ramaseshan,et al.  Performance characteristics of a microMOSFET as an in vivo dosimeter in radiation therapy. , 2004, Physics in medicine and biology.

[22]  Abdelhamid Saoudi,et al.  Feasibility study of using MOSFET detectors for in vivo dosimetry during permanent low-dose-rate prostate implants. , 2006, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.