Theoretical Simulation of Temperature Elevations in Tumors Using Monte Carlo Method and Comparison to Experimental Measurements During Laser Photothermal Therapy

2013 ◽  
Author(s):  
Navid Manuchehrabadi ◽  
Yonghui Chen ◽  
Alexander LeBrun ◽  
Ronghui Ma ◽  
Liang Zhu
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Treatment Protocol ◽  
Gold Nanorod ◽  
Theoretical Simulation ◽  
The Past ◽  
Geometric Ratio ◽  
Laser Photothermal Therapy

Nanotechnology using gold nanoshells or nanorods is a newly developed hyperthermia approach and has been tested in the past several years in cancer treatment.1–2 Gold nanorods have a diameter of ∼10 nm and an aspect ratio of approximately four. By varying the geometric ratio, the nanostructures can be tuned to have strong absorption and scattering to a specific laser wavelength. Designing an optimal treatment protocol of laser photothermal therapy requires understanding of gold nanorod deposition inside the tumor after injection, its resulted specific absorption rate (SAR) distribution, and the ultimate temperature field in the tumor during the treatment. Recent microCT studies by our group have suggested that the gold nanorod solution injected into PC3 prostatic tumors results in an almost uniform distribution of the gold nanorods in the tumors.3 The Monte Carlo method has been used in the past to determine the heating pattern (SAR) of laser-tissue thermal interaction.4 However, the accuracy of the theoretical simulation of the temperature fields in tumors relies on precise measurements of the optical properties of the tumors with nanorods presence.

MicroCT Imaging and In Vivo Temperature Elevations in Implanted Prostatic Tumors in Laser Photothermal Therapy Using Gold Nanorods

2012 ◽  
Vol 3 (2) ◽  
Author(s):  
N. Manuchehrabadi ◽  
A. Attaluri ◽  
H. Cai ◽  
R. Edziah ◽  
E. Lalanne ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Imaging System ◽  
Laser Energy ◽  
Gold Nanorod ◽  
Laser Irradiance ◽  
Theoretical Simulation ◽  
Microct Imaging ◽  
Laser Photothermal Therapy

In this study, in vivo animal experiments are performed on implanted xenograph prostatic tumors in nude mice to investigate enhanced laser energy absorption in the tumors by an intratumoral injection of gold nanorod solutions. In vivo temperature mapping of the tumors during laser photothermal therapy has shown the feasibility of elevating tumor temperatures higher than 50 °C using only 0.1 ml nanorod solution and a low laser irradiance of 1.6 W/cm2 incident on the tumor surface. The temperature profile suggests that normal tumor tissue still absorbs some amount of the laser energy without nanorod presence; however, the injected nanorods ensure that almost all the laser energy is absorbed and confined to the targeted tumors. The inverse relationship between the temperature elevations and the tumor size implies a relatively uniform spreading of the nanorods to the entire tumor, which is also shown by microcomputed tomography (microCT) imaging analyses. The feasibility of detecting 250 OD gold nanorod solution injected to the tumors is demonstrated via a high resolution microCT imaging system. Compared to other nanostructures, the gold nanorods used in this study do not accumulate surrounding the injection site. The relatively uniform deposition of the nanorods in the tumors observed by the microCT scans can be helpful in future study in simplifying theoretical simulation of temperature elevations in tumors during laser photothermal therapy.

Computational Simulation of Temperature Elevations in Tumors Using Monte Carlo Method and Comparison to Experimental Measurements in Laser Photothermal Therapy

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
Navid Manuchehrabadi ◽  
Yonghui Chen ◽  
Alexander LeBrun ◽  
Ronghui Ma ◽  
Liang Zhu
Keyword(s):  
Monte Carlo ◽  
Optical Properties ◽  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Energy Deposition ◽  
Thermal Damage ◽  
Laser Energy ◽  
Simulated Temperature ◽  
Laser Energy Absorption ◽  
Laser Photothermal Therapy

Accurate simulation of temperature distribution in tumors induced by gold nanorods during laser photothermal therapy relies on precise measurements of thermal, optical, and physiological properties of the tumor with or without nanorods present. In this study, a computational Monte Carlo simulation algorithm is developed to simulate photon propagation in a spherical tumor to calculate laser energy absorption in the tumor and examine the effects of the absorption (μa) and scattering (μs) coefficients of tumors on the generated heating pattern in the tumor. The laser-generated energy deposition distribution is then incorporated into a 3D finite-element model of prostatic tumors embedded in a mouse body to simulate temperature elevations during laser photothermal therapy using gold nanorods. The simulated temperature elevations are compared with measured temperatures in PC3 prostatic tumors in our previous in vivo experimental studies to extract the optical properties of PC3 tumors containing different concentrations of gold nanorods. It has been shown that the total laser energy deposited in the tumor is dominated by μa, while both μa and μs shift the distribution of the energy deposition in the tumor. Three sets of μa and μs are extracted, representing the corresponding optical properties of PC3 tumors containing different concentrations of nanorods to laser irradiance at 808 nm wavelength. With the injection of 0.1 cc of a 250 optical density (OD) nanorod solution, the total laser energy absorption rate is increased by 30% from the case of injecting 0.1 cc of a 50 OD nanorod solution, and by 125% from the control case without nanorod injection. Based on the simulated temperature elevations in the tumor, it is likely that after heating for 15 min, permanent thermal damage occurs in the tumor injected with the 250 OD nanorod solution, while thermal damage to the control tumor and the one injected with the 50 OD nanorod solution may be incomplete.

In situ tuning of gold nanorod plasmon through oxidative cyanide etching

2016 ◽  
Vol 18 (23) ◽  
pp. 15619-15624 ◽  
Author(s):  
Aquiles Carattino ◽  
Saumyakanti Khatua ◽  
Michel Orrit
Keyword(s):  
Gold Nanorods ◽  
Plasmon Resonance ◽  
Photothermal Therapy ◽  
Red Shift ◽  
Gold Nanorod

Single gold nanorods exhibit great opportunities for bio-sensing, enhanced spectroscopies and photothermal therapy. We show how to red-shift the plasmon resonance of single nanorods controllably.

The Past and Future of the Monte Carlo Method in Thermal Radiation Transfer

2021 ◽  
Author(s):  
John R. Howell ◽  
Kyle Daun
Keyword(s):  
Monte Carlo ◽  
Energy Transfer ◽  
Monte Carlo Method ◽  
Radiation Transfer ◽  
Massively Parallel ◽  
Radiative Energy ◽  
Quantum Computers ◽  
The Past ◽  
Radiative Energy Transfer ◽  
The Monte Carlo Method

Abstract The history and progress in Monte Carlo methods applied to radiative energy transfer are reviewed, with emphasis on advances over the past 25 years. Unresolved issues are outlined, and comments are included about the outlook for the method as impacted by the advances in massively parallel and quantum computers.

Visualization and Quantification of Gold Nanorods Distribution in Prostatic Tumors Using MicroCT Imaging

2012 ◽  
Author(s):  
N. Manuchehrabadi ◽  
A. Attaluri ◽  
H. Cai ◽  
R. Edziah ◽  
E. Lalanne ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Cell Damage ◽  
Critical Mass ◽  
Three Dimensional ◽  
Transport Processes ◽  
Temperature Fields ◽  
Systemic Delivery ◽  
High Concentration ◽  
Laser Photothermal Therapy

One uncertainty in use of gold nanorods for laser photothermal therapy is the non-uniform spreading of gold nanorods in tissue after either systemic delivery or intratumoral injections. High concentration of gold nanorods in certain areas influences the resulted optical absorption of the laser and thermal damage to tumors. This also provides challenges in designing optimal heating protocols via modeling thermal transport in laser photothermal therapy. For successful cancer treatment, the tissue should be heated with minimum thermal dosage to induce tumor cell damage, while minimizing overheating in the surrounding healthy tissues. Thus, one of the main challenges for reliable cancer therapy is to precisely control loading and distribution of gold nanorods in the tumour tissue. The critical mass transport processes are the distribution of gold nanorods after injection to the tumor and the redistribution of gold nanorods during laser treatment. Since tumors are opaque, nanostructure distribution in tissue is often studied either by theoretical modeling approaches1, or via dye enhanced imaging on superficial layers of tumors.2 It is important to find a technique which can directly visualize and analyze three-dimensional nanostructure distribution of tumors. Three-dimensional reconstructions of tumors with the ability to trace gold nanorod spreading have the potential for precise theoretical simulation of temperature fields. Previous studies showed that computer tomography (CT) scan is a promising technique to be utilized to characterize the distribution of intratumorally injected magnetic nanoparticles in tumors 3.

Treatment efficacy of laser photothermal therapy using gold nanorods

2013 ◽  
Vol 12 (2) ◽  
pp. 157 ◽  
Author(s):  
Navid Manuchehrabadi ◽  
Raheleh Toughiri ◽  
Charles Bieberich ◽  
Hong Cai ◽  
Anilchandra Attaluri ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Treatment Efficacy ◽  
Photothermal Therapy ◽  
Laser Photothermal Therapy

Core–shell gold nanorod@mesoporous-MOF heterostructures for combinational phototherapy

Nanoscale ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 131-137
Author(s):  
Zehao Zhou ◽  
Jian Zhao ◽  
Zhenghan Di ◽  
Bei Liu ◽  
Zhaohui Li ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Metal Organic Frameworks ◽  
Gold Nanorod ◽  
Core Shell ◽  
Tumor Treatment ◽  
Metal Organic

A core–shell heterostructure consisting of plasmonic gold nanorods and porphyrinic metal–organic frameworks is synthesized as a promising platform to combine photodynamic therapy and photothermal therapy for enhanced tumor treatment.

Temperature Elevations in Implanted Prostatic Tumors During Laser Photothermal Therapy Using Nanorods

2011 ◽  
Author(s):  
L. Zhu ◽  
A. Attaluri ◽  
N. Manuchehrabadi ◽  
H. Cai ◽  
R. Edziah ◽  
...  
Keyword(s):  
Targeted Delivery ◽  
Photothermal Therapy ◽  
Near Infrared ◽  
Laser Energy ◽  
Laser Wavelength ◽  
Gold Nanoshells ◽  
Surrounding Tissue ◽  
Geometric Ratio ◽  
Wide Range ◽  
Laser Photothermal Therapy

Gold nanoshells or nanorods are newly developed nanotechnology in laser photothermal therapy for cancer treatments in recent years [1–10]. Gold nanoshells consists of a solid dielectric nanoparticle core (∼100 nm) coated by a thin gold shell (∼10 nm). Gold nanorods have a diameter of 10 nm and an aspect ratio of approximately four. Nanorods may be taken up by tumors more readily than nanoshells due to nanorods’ smaller size. By varying the geometric ratio, both nanoshells and nanorods can be tuned to have strong absorption and scattering to a specific laser wavelength. Among a wide range of laser wavelengths, the near infrared (NIR) laser at ∼800 nm is most attractive to clinicians due to its deep optical penetration in tissue. Therefore, the tissue would appear almost “transparent” to the 800 nm laser light before the laser reaches the nanoshells or nanorods in tumors, with minimal laser energy wasted by the tissue without the nanostructures. The laser energy absorbed in an area congregating by the nanostructures is transferred to the surrounding tissue by heat conduction. This approach not only achieves targeted delivery of laser energy to the tumor, but also maximally concentrates a majority of the laser energy to the tumor region.

scholarly journals The application of a modified Monte Carlo method in the simulation of settlement pattern’s spatial development in the example of Mstów (Śląskie voivodship, Poland)

2016 ◽  
Vol 20 (3) ◽  
pp. 19-31
Author(s):  
Oskar Wolski
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Human Factor ◽  
Land Development ◽  
Spatial Development ◽  
The Past ◽  
Planning Methodology ◽  
Traditional Approaches ◽  
The Village ◽  
New Buildings

Abstract The first aim of the article is to propose the simulation of the settlement patterns development as an element of spatial planning methodology. In order to conduct such a simulation, a modified Monte Carlo method can be used. It approximates the spatial distribution of a studied phenomenon based on numerical calculations and implemented variables. Referring to previous works in which the method was applied, the author tested it on the village of Mstów. It was assumed that this method could highlight land features that are unreachable using traditional approaches in complex systems analyses. The second aim was to investigate some of the determinants of contemporary spatial development. The conducted simulation demonstrated features of Mstów settlement pattern and proved determinants in its future development, including: the existence of areas especially predisposed for building, the decreasing number of new buildings being built, the decreasing importance of factors that were relevant in the past, and a significant relevance of the human factor. It was also proven that land development may occur on areas less predisposed to building.

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