6-MV photon beam modeling for the Varian Clinac iX by using the Geant4 virtual jaw

Autor: Byung Yong Kim, Jeong Ku Kang, Jong Geun Baek, Su Ho Moon, Dong Ho Kim, Hyung Dong Kim, Gwang Won Rho, Sung Kyu Kim
Rok vydání: 2015
Předmět:
Zdroj: Journal of the Korean Physical Society. 67:147-152
ISSN: 1976-8524
0374-4884
DOI: 10.3938/jkps.67.147
Popis: Most virtual source models (VSMs), with the exception of the patient-dependent secondary collimator (jaw), use beam modeling. Unlike other components of the treatment head, the jaw absorbs many photons generated by bremsstrahlung, which decreases the efficiency of the simulation. In the present study, a new method of beam modeling using a virtual jaw was applied to improve the calculation efficiency of VSM. This new method of beam modeling was designed so that the interaction was not generated in the jaw. The results for the percentage depth dose and the profile of the virtual jaw VSM calculated in a homogeneous water phantom agreed with the measurement results for the CC13 cylinder-type ion chamber to within an error of 2%, and the 80–20% penumbra width agreed with the measurement results to within an error of 0.6 mm. Compared with the existing VSM, in which a great number of photons are absorbed, the calculation efficiency of the VSM using the virtual jaw is expected to be increased by approximately 67%.
Databáze: OpenAIRE
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