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2010 | 16 | 1 | 11-21
Tytuł artykułu

Position of effective electron source for shielded electron beams from a therapeutic linear accelerator

Treść / Zawartość
Warianty tytułu
Języki publikacji
EN
Abstrakty
EN
The effective electron source positions for the standard electron cones and for the shielded field sizes with cerrobend inserts were measured based on Inverse Square Law (ISL) and the Inverse Slope (IS) method for various electron energies.The charge measurements were carried out using a 0.6 cc ion chamber (PTW, Type 30001) connected to a PTW Unidos E digital electrometer in a polystyrene phantom for electron beam energies of 6-18 MeV. The resultant charge for 100 MU setting was measured at nominal source to surface distances (SSDs) of 100-120 cm for cone and cerrobend defined field sizes.The effective SSD (SSDeff) was found to be different for the same field size defined by electron applicator and the cerrobend shield placed in 25×25 cm standard cone. Strong dependency of SSDeff with field size and electron beam energy was noticed.The results from the ISL and IS method are consistent, hence either of the two methods can be used to determine the effective source position. Whenever treatment is to be given with shielded electron portal, the SSDeff for that field needs to be determined. Same SSDeff as that of the standard cone can be used for minimum shielded electron portals.
Wydawca
Rocznik
Tom
16
Numer
1
Strony
11-21
Opis fizyczny
Daty
wydano
2010-01-01
online
2011-05-05
Twórcy
  • Medical Physics Department, Oncology Center, King Abdul Aziz Hospital and Oncology Center, Jeddah 21456, Saudi Arabia
  • Department of Radiation Physics, Kidwai Memorial Institute of Oncology, Bangalore, India
Bibliografia
  • Almond PR. Radiation Physics of Electron Beams. In: Tapley N, editor. Clinical Applications of the Electron Beams. New York: John Wiley & Sons; 1976. p. 7-80.
  • Cecatti ER, Goncalves JF, Cecatti SG, da Penha Silva M. Effect of the accelerator design on the position of the effective electron source. Med Phys. 1983 Sep-Oct;10(5):683-686.[Crossref]
  • Faermann S, Krutman Y, Weinstein M. A Comparison of the method of determination of virtual sources for electron beams. Proc. of the 5th Clinac User's Meeting; USA. 1983.
  • Al-Ghazi MS, Lingman D, Arjune B, Gilbert LD, Thekkumthala J. Characteristics parameters of 6-21 MeV electron beams from a 21 MV linear accelerator. Med Phys. 1991;18:821-828.
  • Hogstrom KR. Evaluation of electron pencil beam dose calculation. Med Phys. 1985;12:554-557.
  • ICRU REPORT 35. Radiation Dosimetry: Electron Beams with Energies Between 1 and 50 MeV. 1984.
  • Jamshidi A, Kuchnir FT, Reft CS. Determination of the source position for the electron beams from a high energy linear accelerator. Med Phys. 1986;13:942-945.[PubMed][Crossref]
  • Khan FM. Clinical electron beam dosimetry. Proceedings of the 1986 Summer School of the AAPM. New York (NY): p. 194-246.
  • Khan FM, Sewchand W, Levitt SH. Effect of airspace on depth dose in electron beam therapy. Radiology. 1978;126:249-251.
  • Meyer J, Palta J, Hogstrom K. Demonstration of relatively new electron dosimetry measurement techniques on the Mevatron 80. Med Phys. 1984 Sep-Oct;11(5):670-677.[Crossref]
  • Mills MD, Hogstrom KR, Almond PR. Prediction of electron beam output factors. Med Phys. 1982 Jan-Feb;9(1):60-68.[Crossref][PubMed]
  • Ravikumar M, Ravichandran R. Effect of shielding on virtual source position for electron beams from a Clinac-1800 linear accelerator. J Med Phys. 1999;24:21-24.
  • Schroder-Babo P. Determination of the virtual electron sources of a betatron. Acta Radiol. 1983; 364(suppl):7-10.
  • Sharma AK, Supe SS, Sathiya Narayanan VK, Subbarangaiah K. Determination of virtual SSDs for electron beams from a dual energy linear accelerator. Strahlenther Onkol. 1992 Jul;168(7):402-405.[PubMed]
  • Sweeney LE, Gur D, Bukovitz AG. Scatter component and its effect on virtual source and electron beam quality. Int J Radiat Oncol Biol Phys. 1981 Jul;7(7):967-971.[PubMed][Crossref]
  • Khan FM, Doppke KP, Hogstrom KR, Kutcher GJ, Nath R, Prasad SC et al. Clinical electron-beam dosimetry: report of AAPM Radiation Therapy Committee Task Group No. 25. Med Phys. 1991 Jan-Feb;18(1):73-109.[Crossref]
  • Thomadsen BR, Asp LW, Van de Geijn J, Paliwal BR, PoCheng C. Perturbation of electron beam doses as a function of SSD due to the use of shielding blocks on the Clinac-18. Med Phys. 1981 Jul-Aug;8(4):507-509.[Crossref]
Typ dokumentu
Bibliografia
Identyfikatory
Identyfikator YADDA
bwmeta1.element.-psjd-doi-10_2478_v10013-010-0002-z
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