Assessment of an Unshielded Electron Field Diode Dosimeter for Beam Scanning in Small- to Medium-Sized 6 MV Photon Fields

  • سال انتشار: 1392
  • محل انتشار: مجله فیزیک پزشکی ایران، دوره: 10، شماره: 1
  • کد COI اختصاصی: JR_IJMP-10-1_006
  • زبان مقاله: انگلیسی
  • تعداد مشاهده: 490
دانلود فایل این مقاله

نویسندگان

Mohammad Amin Mosleh-Shirazi

۱- Center for Research in Medical Physics and Biomedical Engineering, Shiraz University of Medical Sciences, Shiraz, Iran ۲- Physics Unit, Department of Radiotherapy and Oncology, Namazi Hospital, Shiraz University of Medical Sciences, Shiraz,

A. Ketabi

Student Research Committee, and Department of Medical Physics, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

Sareh Karbasi

Physics Unit, Department of Radiotherapy and Oncology, Namazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran

Reza Faghihi

Department of Medical Radiation and Radiation Research Center, School of Mechanical Engineering, Shiraz University, Shiraz, Iran

چکیده

Introduction Radiotherapy planning systems require many percentage depth dose (PDD) and profile measurements and there are various dosimeters that can be used to obtain these scans. As dose perturbation is particularly troublesome in smaller photon fields, using a low-perturbation, unshielded electron field diode (EFD) in these fields is of interest. The aim of this work was to investigate the suitability of an unshielded diode for beam scanning in 3×3 cm2, 5×5 cm2, and 10×10 cm2, 6 MV fields. Materials and Methods An EFD was used for all the scans. For comparisons in profile measurements, a tungsten-shielded photon field diode (PFD) was also used. PDDs were measured using the PFD and an RK ionization chamber. Results Very good agreement (0.4%) was found between the PDDs measured with EFD and PFD for the two larger fields. However, the difference between them exceeded 1.0% slightly for the smallest field, which may be attributed to the effect of the larger PFD perturbation. The RK chamber PDDs around 10 cm depth were 1-2% lower than those measured with the diodes. There was good agreement ( Conclusion The EFD generally agrees well with the PFD and may even perform better in smaller fields.

کلیدواژه ها

Electron Field Diode, Photon Field Diode, Radiotherapy Beam Scanning, RK Ionization Chamber, Small and Medium Fields

اطلاعات بیشتر در مورد COI

COI مخفف عبارت CIVILICA Object Identifier به معنی شناسه سیویلیکا برای اسناد است. COI کدی است که مطابق محل انتشار، به مقالات کنفرانسها و ژورنالهای داخل کشور به هنگام نمایه سازی بر روی پایگاه استنادی سیویلیکا اختصاص می یابد.

کد COI به مفهوم کد ملی اسناد نمایه شده در سیویلیکا است و کدی یکتا و ثابت است و به همین دلیل همواره قابلیت استناد و پیگیری دارد.