Browse > Article

Characteristics of Dose Distribution at Junctional Area Using the Divergency Cutout Block in the Abutted Field of Photon and Electron Beams  

Im, In-Chul (Department of Radiological Science, Dongeui University)
Lee, Jae-Seung (Department of Radiation Oncology, Good Samaritan Hospital)
Publication Information
Journal of Radiation Protection and Research / v.36, no.3, 2011 , pp. 168-173 More about this Journal
Abstract
This study investigated characteristics of dose distribution at junction field of X-ray and electron beams according to the method for fabricating the insert block on the electron cone. Insert block were fabricated to the divergency cutout block and the straight cutout block. For the 6 MV X-ray and 10 MeV nominal energy of electron beam, we was adjacent to the light field of X-ray and electron beam at a surface of matrix chamber and measured to beam profile of abutted field in the 0, 1, 2, 3 cm measurement depth. As a result, characteristics of dose distribution at junction field, straight block was existent that over dose area exceed the give dose more than 5% and under dose area with a rapid change in dose distribution. However, divergency block had remarkably decreased the over dose area caused by the lateral scattering effects of decrease, and being existed uniformity dose distribution in the junction field. Therefore, divergency block were the benefits of radiation dose delivery, in order to applied the clinical, measurement of electron beams according to the fabrication method of the block should be considered carefully.
Keywords
Junction field; Dose distribution; Beam profile; Treatment planning system (TPS);
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 AAPM. Comprehensive QA for radiation oncology: Report of AAPM Radiation Therapy Committee Task Group No. 40. Med. Phys. 1994;21:581-618.
2 ICRU. Radiation dosimetry, Electrons with intial energy between 1 and 50 MeV. Report No. 21. Washington D,C: International Commission on Radiation Units and Measurements, 1972.
3 Kim JK, Kim KH, Oh YK, Kim JK, Jeong DH, Shi KC, Yan KM, Cho MJ, Park IK, Kwon HC, Moon SR, Yun HG. Dose distribution at junctional area for head and neck radiotherapy. Korean J. Med. Phys. 1972;12(2): 161-169.
4 Kelin EE, Low DA, Purdy JA. Changes in electron beam dosimetry with a new scattering foil-applicator system on a CL2100C. Int. J. Radiat. Oncol. Biol. Phys. 1995;32(2):483-490.   DOI   ScienceOn
5 Choi DR, Wolters J, Mason D, Bailie A. Modified sector-integration method for predicting the outputfactors of electron beams inculuding extended source to surface distance. Phys. Med. Biol. 2000;45(11):3367-3372.   DOI   ScienceOn
6 Choi DR, Mobit PN, Breitman KE. The clinical implementation of a method for calculating the output factor and percent depth dose for an electron beam. Phys. Med. Biol. 2003;48(7):899-908.   DOI   ScienceOn
7 Faddegon BA, Villarreal-Barajas JE. Final aperture superposition technique applied to fast calculation of electron output factors and depth dose curves. Med. Phys. 2005;32(11):3286-3294.   DOI   ScienceOn
8 Goo EH, Lee JS, Kim MJ, Dong KR, Kweon DC, Chung WK. Physical characteristics of the electron beam distribution according to the fabrication method of the block; Based on a linear accelerator. J. Kor. Phys. Soc. 2010;57(3):506-513.   DOI   ScienceOn
9 Poppe B, Blechschmidt A, Djouguela A, Kollhoff R, Rubach A, Willborn KC, Harder D. Two-dimensional ionization chamber arrays for IMRT plan verification. Med. Phys. 2006;33(4):1005-1015.   DOI   ScienceOn
10 Spezi E, Angelini AL, Romani F, Ferri A. Characterization of a 2D ion chamber array for the verification of radiotherapy treatments. Med. Phys. 2005;50(14):3361-3373.   DOI   ScienceOn
11 Ostinelli A, Gelosa S, Frigerio M, Monti AF. Air bubble effect during alloy cooling in shielding blocks radiotherapy. Radiol. Med. 1998;96(4):390-393.
12 Mahadevan A, Lee A, Holupka E, Sampson C, Liu X. An optimized multileaf feathering technique for matching single isocenter half beam 3 field head and neck radiation. Int. J. of Radiat. Oncol. Biol. Phys. 2005;63(1):S499.
13 Armstrong DI, Tait JJ. The matching of adjacent fields in radiotherapy. Radiology. 1973;108(2):419-422.   DOI
14 Williamson TJ. A technique for matching orthogonal megavoltage fields. Int. J. Radiat. Oncol. Biol. Phys. 1979;5(1):111-116.   DOI   ScienceOn
15 Kahn FM. The physics of radiation therapy. 4th edition. 1996.
16 Bentel GC. Radiation Therapy Planning. 2nd edition. 1996.
17 Jonhnson JM, Khan FM. Dosimetric effects of abutting extended SSD electron fields with photons in the treatment of head and neck cancers. Int. J. Radiat. Oncol. Biol. Phys. 1994;28(3):741-747.   DOI   ScienceOn
18 Verhaegen F, Tayler RS, Liu HH, Nahum AE. Backscatter towards the monitor ion chamber in high-energy photon and electron beams; charge integration versus Monte Carlo simulation. Phys. Med. Biol. 2000;45(11):3159-3170.   DOI   ScienceOn
19 Hopfan S, Reid A, Simpson L, Ager PJ. Clinical application arising from overlapping of adjacent radiation fields. Int. J. Radiat. Oncol. Biol. Phys. 1977;2(7):801-808.   DOI   ScienceOn
20 Jette D, Walker S. Electron dose calculation using multiple scattering theory; Evaluation of a new model for inhomogeneities. Med. Phys. 1992;19(5): 1241-1254.   DOI   ScienceOn
21 Jette D. Electron beam dose calculation in radiation therapy physics. 2nd edition. 1995.
22 Bruinvis IAD, Amste AV, Elevelt AJ, Larse RV. Calculation of electron beam dose distributions of arbitrarily shaped field. Phys. Med. Biol. 1983;28(6): 667-683.   DOI   ScienceOn
23 Bilge H, Kucucuk H, Okutan M, Cakir A, Kucucuk S. Matchline dosimetry of half beam technique at fixed SSD using co-60 and 4 MV photons in the treatment of head and neck tumors. Physica medica. 2003;9(1): 37-42.
24 Popovtzer A, Eisbruch A. Advances in radiation therapy of head and neck cancer. Expert Rev Anticancer Ther. 2008;8(4):633-644.   DOI   ScienceOn