Evaluation of Using Radiographic Films in Measurements of Penumbra Width for Radiotherapy Applications and Stereotactic Radiosurgery
The accuracy of treatment field size in is a success key in cancer radiotherapy. As Increase in dose may lead to overdose side effects, and decrease in dose lead to subtherapeutic effect which increased incidence of tumor recurrence or incomplete recovery of patient. Many physical parameters should be measured very accurately in order to predict the dose distribution as physical penumbra of radiation fields. Ionization chamber is considered as slandered tools for measuring penumbra. Mega voltage x-ray energy penumbra is measured using ionization chamber due to its high accuracy in measuring absolute dose. This technique can produce the gold standard for penumbra measurements; however, it is a very time consuming and demanding process. Aim of this work is to evaluate the using radiographic films in penumbra width measurements for radiotherapy applications and stereotactic radiosurgery by comparing results obtained by standard ionization chambers to radiographic films as new tool for penumbral width measurements. Comparison between penumbra region measured by ionization chamber and o-xmat v Kodak radiographic films were carried out under the same physical and dosimeteric conditions. Penumbra width differences were found to be less than 1 mm for 6 mev, 15 mev photon beam and 6 mv, 15 mv electron beam used in radiotherapy. Measured differences were considered very small and has no effect on penumbra width measurements however o-xmat v Kodak films provide fast .easy and economic method for penumbra measurement used in radiotherapy dosimetery.
- C. B. Saw, K. M. Ayyangar, W. Zhen, R. B. Thompson, and C. A. Enke,“Commissioning and quality assurance for MLC-based IMRT,” Med. Dosim 26, 125–133 (2000).
- T. LoSasso, C. S. Chui, and C. C. Ling, “Comprehensive quality assurance for the delivery of intensity modulated radiotherapy with a multileaf collimator used in the dynamic mode,” Med. Phys. 28, 2209–2219 (2001).
- D.Low, J. Moran, J.F.Dempsey, L. Dong, and M. Oldham, “Dosimetery Tools and Techniques for IMRT,” Medical Physics, 38, 1313-1338. (2011)
- H.Hrsak, M. Major, T. Grego, J. Bibic, and Z. Heinrich, “Correction of Measured Gamma-Knife Output Factors for Angular Dependence of Diode Detectores and PinPiont Ionization Chamber,” Physica Medica, 30, 914-919.(2014)
- T. Rachi, Y. Iwamoto, M. Tamura, K. Ota, T. Shimosato, Y. Obata, and M. Komori, “ Study of Collimator Scatter Factor (Sc) and Phantom Scatter Factor (Sp) Using Monte Carlo Simulation,” Proceeding of the 19th EGS Users’ Meeting in Japan, KEK Proc 2012-7, 76. (2012)
- S. J. Shepard, J. Wang, M. Flynn, E. Gingold, L. Goldman, K. Krugh, D. L.Leong, E. Mah, K. Ogden, D. Peck, E. Samei, J. Wang, and C. E. Willis, "An exposure indicator for digital radiography: AAPM Task Group 116(executive summary),” Med. Phys.36, 2898–2914 (2009).39
- International Electro technical Commission, Medical electrical equipment–Exposure index of digital x-ray imaging systems–Part1: Definitions and requirements for general radiography, IEC 62494-1, International Electro technical Commission ed. 1.0, Geneva, 2008.
Copyright (c) 2018 JOURNAL OF ADVANCES IN PHYSICS
This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors retain the copyright of their manuscripts, and all Open Access articles are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided that the original work is properly cited.