Effect of the thermoplastic masks on dose distribution in the build-up region for photon beams

• Autorzy: Półtorak M. , Fujak E. , Kukołowicz P.

Identyfikatory

DOI

10.1515/pjmpe-2016-0001

• Języki publikacji: EN

Abstrakty

EN

The aim of the study was to investigate the influence of thermoplastic masks material (Klarity Medical&Equipment Co., Guangzhou, China) with different diameters of holes (ϕ 0.25 cm and ϕ 0.40 cm) on the dose distribution in the build-up region for photon beams. Measurements were made for external radiation beams produced by the linear accelerator (TrueBeam, Varian Medical Systems, Inc., Palo Alto, CA, USA) using the Markus parallel plane ionization chamber and the Unidos electrometer (both from PTW, Freiburg, Germany). Measurements were made in a solid water phantom for two photon energies 6 MV and 15 MV, at 90 cm source to skin distance, for four fields of 5 cm × 5 cm, 10 cm × 10 cm, 15 cm × 15 cm and 20 cm × 20 cm. Compared to the open field, the maximum dose with mask was closer to the surface of the phantom by about 1.4 mm and 1.2 mm for 6 MV and 15 MV X-Rays, respectively. The surface dose increase from 10% to 42% for 6 MV and from 5% to 28% for 15 MV X-Rays.

Słowa kluczowe

EN

radiotherapy; thermoplastic mask; X-ray; percentage depth dose; AAPM TG 176

• Wydawca: Polskie Towarzystwo Fizyki Medycznej
• Czasopismo: Polish Journal of Medical Physics and Engineering
• Rocznik: 2016
• Tom: Vol. 22, Iss. 1
• Strony: 1--4
• Opis fizyczny: Bibliogr. 7 poz., rys., tab.

Twórcy

autor

Półtorak M.

• Cancer Center-Institute of Oncology, Wawelska 15B, Warsaw

autor

Fujak E.

• Cancer Center-Institute of Oncology, Wawelska 15B, Warsaw

autor

Kukołowicz P.

• Cancer Center-Institute of Oncology, Wawelska 15B, Warsaw

Bibliografia

• [1] Lee N, Chuang C, Quivey JM, et al. Skin toxicity due to intensity-modulated radiotherapy for head-and-neck carcinoma. Int J Radiat Oncol Biol Phys. 2002;53(3):630-637.10.1016/S0360-3016(02)02756-6.
• [2] Olch AJ, Gerig L, Li H, et al. Dosimetric effects caused by couch tops and immobilization devices: Report of AAPM Task Group 176. Med Phys. 2014;41(6):061501.10.1118/1.4876299.
• [3] Wittych J, Kukołowicz P. Effect of beam spoiler on radiation dose in the build-up region for 6-MV X-ray. Rep Prac Oncol Radiother. 2003;8(1):15-23.10.1016/S1507-1367(03)70992-4.
• [4] Kukołowicz P. Charakterystyka wiązek terapeutycznych fotonów i elektronów. Kielce, 2001.
• [5] Gerbi BJ, Khan FM. Measurement of dose in the buildup region using fixed-separation plane-parallel ionization chambers. Med Phys. 1990;17(1):17-24.10.1118/1.5965222106611.
• [6] Velkley DE, Manson DJ, Purdy JA, Oliver GD Jr. Build-up region of megavoltage photon radiation sources. Med Phys. 1975;2(1):14-19.10.1118/1.594158805358.
• [7] Apipunyasopon L, Srisatit S, Phaisangittiskul N. An investigation of the depth dose in the build-up region, and surface dose for a 6-MV therapeutic photon beam: Monte Carlo simulation and measurements. J Radiat Res. 2013;54(2):374-382.10.1093/jrr/rrs097358993523104898.