1. Oct 13th, 2015
Ryerson University
Department of Medical Physics
Thesis Project Title:
Monte Carlo Simulations on Gold Nanoparticle as a
Contrast Agent
Author:
Ferdos Albayedh
Student ID#:
4390
Supervisor:
Dr. James Chow

2. Monte Carlo Simulations on Gold Nanoparticle as a Contrast Agent
In radiation therapy for cancer treatment, delivering high radiation dose pointing to destroy a
tumor does not just affect the tumor itself, but the healthy tissues surrounding that tumor, which
could lead to healthy tissue damage. To decrease this risk, a study based on using a heavy-atom
contrast agent such as gold nanoparticle will act as an important role to reach this goal.
There are advantageous physical properties of this agent, which makes it efficiently qualified for
this study. It increases the contrast of the tumor in medical imaging; therefore the targeting of
radiation beam would be accurately increased. Moreover, it enhances the absorption of the dose
in the tumor, which in the end results in diminishing the cancer cell (Ahn, Jung and Lee, 2013).
The focus of this project is to determine the relationship between the contrast ratio and
concentration of the gold nanoparticle in radiotherapy. The method used to calculate the contrast
ratio of the tumor with the addition of gold nanoparticle is the EGSnrc Monte Carlo code. There
will be different gold nanoparticle concentrations and tissue media used; such as soft tissue,
bone, and lung. Therefore, the investigation will be accommodated to determine the linkage
between the contrast ratio, tissue heterogeneity and gold nanoparticles.
The plan is going to include creating a phantom with different materials, and they are found from
the library available in the program. There are three important factors to be considered, which
are AuNP, E of keV Photon Beam, and thickness of the tissue. The Phantom will involve two
volumes. The first, which represents the tissue and it is the thicker part of the phantom. The

3. second is the thinner part, which will allow the detection of the radiation dose after delivering the
photon beam through the phantom. At first the phantom will not include gold nanoparticle, for
the reason of collecting the data then compare that data with the data collected after the addition
of the gold nanoparticle AuNP. The materials for the first step of the investigation are water and
air. After the data is noted, the second step will include the addition of AuNP to water. Hence,
the contrast ratio will be calculated containing the results from both data with the addition of
AuNP and without. It is expected to use other materials which represent the tissue, for example,
lung and bone as an advanced approach. A similar procedure will be applied to calculate the
contrast ratio.
The results expected to be observed is that the values will be smaller numbers in the second
volume for the addition of the AuNP. It is a positive outcome. However, the aim here is to know
the answer to this question, which tissue used will give the better results and which size of the
phantom would be the idealist in this study? There will be different outcomes to be discovered
and the more the investigation there is, the more results to compare to reach the goal of this
project.
The importance of this study is to intent to discover an approach how to make cancer treatment
in radiotherapy further efficient and productive by using the gold nanoparticles. It is an
outstanding discovery, and further research is going to be done to achieve the purpose.

4. References:
Ahn, S., Jung, S. and Lee, S. (2013). Gold Nanoparticle Contrast Agents in Advanced X-ray
Imaging Technologies. Molecules, 18(5), pp.5858-5890.