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. 2020 May-Jun;25(3):428-435.
doi: 10.1016/j.rpor.2020.03.022. Epub 2020 Apr 27.

Study of efficiency in five-field and field-by-field intensity modulated radiation therapy (IMRT) plan using DOSXYZnrc Monte Carlo code

Sitti Yani  1   2 , Indra Budiansah  2 , Kamirul  3 , Mohamad Fahdillah Rhani  4 , Freddy Haryanto  2
Affiliations

Study of efficiency in five-field and field-by-field intensity modulated radiation therapy (IMRT) plan using DOSXYZnrc Monte Carlo code

Sitti Yani et al. Rep Pract Oncol Radiother. 2020 May-Jun.

Abstract

Implementation of a modern treatment technique, such as IMRT, has been improved. In line with that, Monte Carlo (MC) simulations of this technique require the ability of complex beam configurations modelling with respect to the patient. The source 20 DOSXYZnrc with the dynamic and step and shoot technique can be used to simulate the modality. However, they have a different process to obtain the dose distribution in a certain phantom. This study aimed to compare the simulation efficiency and isodose dose distribution in a water phantom from various beam angles and multileaf collimator (MLC) positions in an IMRT plan using source 20. The 30 × 30 × 30 cm3 phantom was irradiated by Varian Clinac iX10MV photon beam with various field sizes from 2 × 2 to 6 × 6 cm2 using some beam angles 5°, 30°, 90°, 180°, and 300° and maintaining the source to surface distance (SSD) of 100 cm. The field-by-field and five-field methods were used to obtain the 3-dimensional (3D) dose distribution. The dose distribution of these methods was compared using the gamma index, DVH analysis, and simulation efficiency. Higher efficiency is better because it implies that it takes less time to reach a given uncertainty. The implementation of source 20 has been validated, with similar results, with validated source in DOSXYZnrc. The identical 3D-dimensions dose distributions using source 20 for dynamic and step and shoot were observed. Two simulations used the same number of histories with the statistical uncertainty of less than 3%. The step and shoot technique was more efficient than the dynamic simulation.

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Figures

Fig. 1
Fig. 1
A flowchart of the Monte Carlo simulation step.
Fig. 2
Fig. 2
Illustration of the Varian Clinac iX and phsp file location.
Fig. 3
Fig. 3
Source 20 of DOSXYZnrc.
Fig. 4
Fig. 4
Simulation step for field-by-field DOSXYZnrc.
Fig. 5
Fig. 5
Isodose contour of (a) field-by-field and (b) five-field simulation for slice number 20th, 35th, 40th, and 45th.
Fig. 6
Fig. 6
Gamma index maps of step and shoot and dynamic IMRT simulation in slice of 20th, 40th, and 60th with acceptance criteria 1%/1 mm and 3%/3 mm.
Fig. 7
Fig. 7
DVH of step and shoot and dynamic technique for water, target, and OAR.
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References

    1. Ma C-M, Pawlicki T, Jiang SB. Monte Carlo verification of IMRT dose distributions from a commercial treatment planning optimization system. Phys Med Biol. 2000;45(9):2483–2495. - PubMed
    1. Sikora M, Muzik J, Söhn M, Weinmann M, Alber M. Monte Carlo vs. pencil beam based optimization of stereotactic lung IMRT. Radiat Oncol. 2009;4:64. - PMC - PubMed
    1. Quino LAV, Hernandez CIH, Papanikolaou N. A Monte Carlo model for independent dose verification in IMRT and VMAT for the Varian Novalis TX with high definition MLC. Int J Cancer Ther Oncol. 2015;3(3):1–7.
    1. Jones AO, Das IJ, Jones F.L. A Monte Carlo study of IMRT beamlets in inhomogeneous media. Med. Phys. 2003;30(3):296–300. - PubMed
    1. Rice RK, Hansen JL, Svensson GK, Siddon R.L. Measurements of dose distributions in small beams of 6 MV x-rays. Phys Med Biol. 1987;32:1087–1099. - PubMed