International Journal of Radiation Research
نشریه پرتو پژوه
Int J Radiat Res
Basic Sciences
http://ijrr.com
79
journal79
2322-3243
2345-4229
10.61186/ijrr
en
jalali
1399
7
1
gregorian
2020
10
1
18
4
online
1
fulltext
en
Investigation of surface and buildup region doses for 6 MV high energy photon beams in the presence of a thermoplastic mask
Medical Physics
Medical Physics
تحقيق بديع
Original Research
<div style="text-align: justify;">Background: The accuracy and the reproducibility of radiotherapy can be provided by using immobilization devices such as thermoplastic masks. In head and neck cancer radiotherapy, the patients are mostly immobilized by using thermoplastic masks. In this study, the effect of the thermoplastic mask to the surface and buildup region doses was investigated by using Markus parallel plate ion chamber, Gafchromic EBT3 film and MOSFET detector for the same field size and different beam angles. Materials and Methods: The measurements were made in a water equivalent solid phantom at the surface and in the buildup region of the 6 MV photon beams at 100 cm source-detector distance for 10 × 10 cm<sup>2</sup> field size and beam angles of 0°, 30°, 60° and 80° with and without thermoplastic mask. Results: The surface doses in 0.07 mm depth using 6MV photon beams without a thermoplastic mask for 10 × 10 cm<sup>2</sup> field size were found 20.3%, 18.8%, and 41.5% for Markus chamber, EBT3 film, and MOSFET detector, respectively. The surface doses using 6 MV photon beams with a thermoplastic mask for 10 × 10 cm<sup>2</sup> field size were found 38.4%, 51.7% and 50.2% for Markus chamber, EBT3 film, and MOSFET detector, respectively. Conclusion: The thermoplastic masks placed on the surface of the medium affect the surface and buildup region doses. The effect of thermoplastic masks to surface and buildup region doses should be determined before use clinically.</div>
Thermoplastic mask, surface dose, MOSFET, EBT3 film.
623
631
http://ijrr.com/browse.php?a_code=A-10-2055-46&slc_lang=en&sid=1
N.D.
Kesen
nazo94@gmail.com
7900319475328460016830
7900319475328460016830
Yes
Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey
C.
Koksal
7900319475328460016831
7900319475328460016831
No
Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey