# The effect of voxel size on dose distribution in Varian Clinac iX 6 MV photon beam using Monte Carlo simulation

## Abstract

Recently, Monte Carlo (MC) calculation method has reported as the most accurate method of predicting dose distributions in radiotherapy. The MC code system (especially DOSXYZnrc) has been used to investigate the different voxel (volume elements) sizes effect on the accuracy of dose distributions. To investigate this effect on dosimetry parameters, calculations were made with three different voxel sizes. The effects were investigated with dose distribution calculations for seven voxel sizes: 1 × 1 × 0.1 cm{sup 3}, 1 × 1 × 0.5 cm{sup 3}, and 1 × 1 × 0.8 cm{sup 3}. The 1 × 10{sup 9} histories were simulated in order to get statistical uncertainties of 2%. This simulation takes about 9-10 hours to complete. Measurements are made with field sizes 10 × 10 cm2 for the 6 MV photon beams with Gaussian intensity distribution FWHM 0.1 cm and SSD 100.1 cm. MC simulated and measured dose distributions in a water phantom. The output of this simulation i.e. the percent depth dose and dose profile in d{sub max} from the three sets of calculations are presented and comparisons are made with the experiment data from TTSH (Tan Tock Seng Hospital, Singapore) in 0-5 cm depth. Dose that scored in voxels is a volume averaged estimatemore »

- Authors:

- Nuclear Physics and Biophysics Division, Physics Department, Institut Teknologi Bandung (Indonesia)
- (Indonesia)
- Tan Tock Seng Hospital (Singapore)

- Publication Date:

- OSTI Identifier:
- 22488903

- Resource Type:
- Journal Article

- Journal Name:
- AIP Conference Proceedings

- Additional Journal Information:
- Journal Volume: 1677; Journal Issue: 1; Conference: 5. international conference on mathematics and natural sciences, Bandung (Indonesia), 2-3 Nov 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 61 RADIATION PROTECTION AND DOSIMETRY; 62 RADIOLOGY AND NUCLEAR MEDICINE; ACCURACY; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DEPTH DOSE DISTRIBUTIONS; DOSIMETRY; MONTE CARLO METHOD; PHANTOMS; PHOTON BEAMS; RADIATION DOSES; RADIOTHERAPY; SINGAPORE

### Citation Formats

```
Yani, Sitti, E-mail: sitti.yani@s.itb.ac.id, Akademi Kebidanan Pelita Ibu, Kendari, Dirgayussa, I Gde E., Haryanto, Freddy, Arif, Idam, and Rhani, Moh. Fadhillah.
```*The effect of voxel size on dose distribution in Varian Clinac iX 6 MV photon beam using Monte Carlo simulation*. United States: N. p., 2015.
Web. doi:10.1063/1.4930646.

```
Yani, Sitti, E-mail: sitti.yani@s.itb.ac.id, Akademi Kebidanan Pelita Ibu, Kendari, Dirgayussa, I Gde E., Haryanto, Freddy, Arif, Idam, & Rhani, Moh. Fadhillah.
```*The effect of voxel size on dose distribution in Varian Clinac iX 6 MV photon beam using Monte Carlo simulation*. United States. doi:10.1063/1.4930646.

```
Yani, Sitti, E-mail: sitti.yani@s.itb.ac.id, Akademi Kebidanan Pelita Ibu, Kendari, Dirgayussa, I Gde E., Haryanto, Freddy, Arif, Idam, and Rhani, Moh. Fadhillah. Wed .
"The effect of voxel size on dose distribution in Varian Clinac iX 6 MV photon beam using Monte Carlo simulation". United States. doi:10.1063/1.4930646.
```

```
@article{osti_22488903,
```

title = {The effect of voxel size on dose distribution in Varian Clinac iX 6 MV photon beam using Monte Carlo simulation},

author = {Yani, Sitti, E-mail: sitti.yani@s.itb.ac.id and Akademi Kebidanan Pelita Ibu, Kendari and Dirgayussa, I Gde E. and Haryanto, Freddy and Arif, Idam and Rhani, Moh. Fadhillah},

abstractNote = {Recently, Monte Carlo (MC) calculation method has reported as the most accurate method of predicting dose distributions in radiotherapy. The MC code system (especially DOSXYZnrc) has been used to investigate the different voxel (volume elements) sizes effect on the accuracy of dose distributions. To investigate this effect on dosimetry parameters, calculations were made with three different voxel sizes. The effects were investigated with dose distribution calculations for seven voxel sizes: 1 × 1 × 0.1 cm{sup 3}, 1 × 1 × 0.5 cm{sup 3}, and 1 × 1 × 0.8 cm{sup 3}. The 1 × 10{sup 9} histories were simulated in order to get statistical uncertainties of 2%. This simulation takes about 9-10 hours to complete. Measurements are made with field sizes 10 × 10 cm2 for the 6 MV photon beams with Gaussian intensity distribution FWHM 0.1 cm and SSD 100.1 cm. MC simulated and measured dose distributions in a water phantom. The output of this simulation i.e. the percent depth dose and dose profile in d{sub max} from the three sets of calculations are presented and comparisons are made with the experiment data from TTSH (Tan Tock Seng Hospital, Singapore) in 0-5 cm depth. Dose that scored in voxels is a volume averaged estimate of the dose at the center of a voxel. The results in this study show that the difference between Monte Carlo simulation and experiment data depend on the voxel size both for percent depth dose (PDD) and profile dose. PDD scan on Z axis (depth) of water phantom, the big difference obtain in the voxel size 1 × 1 × 0.8 cm{sup 3} about 17%. In this study, the profile dose focused on high gradient dose area. Profile dose scan on Y axis and the big difference get in the voxel size 1 × 1 × 0.1 cm{sup 3} about 12%. This study demonstrated that the arrange voxel in Monte Carlo simulation becomes important.},

doi = {10.1063/1.4930646},

journal = {AIP Conference Proceedings},

issn = {0094-243X},

number = 1,

volume = 1677,

place = {United States},

year = {2015},

month = {9}

}