Photon Dose Enhancement Ratio at the Transition Region of Dissimilar Media
Abstract
Accurate measurement was carried out for the dose gradient in Teflon irradiated with filtered X-ray spectra having effective energies of 40 keV and 55 keV when in contact with aluminum, titanium, copper, and tin. At low photon energies, the interface region is only extended for about 10 microns from the interface, therefore, ultra-thin LiF/Teflon discs of the order of 3 microns thick was developed and used to measure directly the dose gradient in Teflon. Due to the relatively large slope of the depth dose curves near the interfaces, a displacement correction factor was introduced to determine the effective measuring point of the detector. A fitting exponential formula is suggested and used to estimate the dose gradient for Bone-Teflon interface. The interface dose for Bone-Teflon is 3.8 times the equilibrium dose at 70 KV, while it is about 3.1 at 100 KV.Downloads
References
Al-Arif, M.S., 2013a. The Effective Measuring Point of Thermoluminescent Detector at the Build-up Region. Journal of Natural Sciences and Mathematics, PK, 52(1), pp.1-7.
Al-Arif, M.S., 2013b. Unity Energy Response Using CaSO4:DY/Teflon. ARO, The Scientific Journal of Koya University, 1(1), pp.14-16. Retrieved from http://dx.doi.org/10.14500/aro.10026.
Chandra, P.J., Johnson, D., Vidyasagar, P. B. , Schreiner, L.J, 2010. Dosimetry of interface region near closed air cavities for Co-60, 6 MV and 15 MV photon beams using Monte Carlo simulations. J Med Phys, 39(2), pp.73-80.
Das, I.J., Kassaee, A., Verhaegen, F. and Moskvin, V.P., 2001. Measurements and Monte Carlo simulations of low-energy photon beams. Rad Phys and Chemistry, 61(3), pp. 593-595.
Joshi, C. P., Darko, J., Vidyasagar, P. B. and Schreiner, L.J., 2010. Dosimetry of interface region near closed air cavities for Co-60, 6 MV and 15 MV photon beams using Monte Carlo simulations. J Med Phys, 35(2), pp.73-80.
Kinhikar, R.A, Tambe, C.M., Patil, K., Mandavkar, M., Deshpande, D.D., Gujjalanavar, R., Yadav, P. and Budrukkar, A, 2014. Estimation of dose enhancement to soft tissue due to backscatter radiation near metal interfaces during head and neck radiotherapy- A phantom dosimetric study with radiochromic film. J Med Phys, 39(1), pp.40-3.
Li XA, Yu C. and Holmes, T., 2000. A systematic evaluation of air cavity dose perturbation in megavoltage X-ray beams. Med Phys, (27), pp.1011-7.
Nicopoulou-Karayianni, K., Koligliatis, T., Donta-Bakogianni, C., Karayiannis, A. and Litsas, J., 2003. Radiation absorbed doses at compact bone-titanium interfaces in diagnostic radiography: a Monte Carlo approach. Dentomaxillofac Radiol, 32(5), pp.327-32.
Shiu, A.S. and Hogstrom, K.R., 1991. Dose in Bone and Tissue near Bone-Tissue interface from electron beam. Int J Radiat Oncol Biol Phys., 21(3), pp.695-702.
Copyright (c) 2014 Maan S. Al-Arif
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Authors who choose to publish their work with Aro agree to the following terms:
-
Authors retain the copyright to their work and grant the journal the right of first publication. The work is simultaneously licensed under a Creative Commons Attribution License [CC BY-NC-SA 4.0]. This license allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
-
Authors have the freedom to enter into separate agreements for the non-exclusive distribution of the journal's published version of the work. This includes options such as posting it to an institutional repository or publishing it in a book, as long as proper acknowledgement is given to its initial publication in this journal.
-
Authors are encouraged to share and post their work online, including in institutional repositories or on their personal websites, both prior to and during the submission process. This practice can lead to productive exchanges and increase the visibility and citation of the published work.
By agreeing to these terms, authors acknowledge the importance of open access and the benefits it brings to the scholarly community.
ARO Journal is a scientific, peer-reviewed, periodical, and OAJ that has no APC or ASC.