A fast and accurate gate model for small field scattering proton beam therapy

, Article 15th IEEE International Symposium on Medical Measurements and Applications, MeMeA 2020, 1 June 2020 through 3 June 2020 ; 2020 Piruzan, E ; Vosoughi, N ; Mahani, H ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2020

Abstract

Proton beam therapy (PBT) is a modern external beam radiation therapy characterized by superior dose distribution. Small field PBT refers to the treatment of tumor sizes less than 7 cm in diameter. In this study, a fast and accurate GATE model was developed and then validated for a small field scattering PBT delivery. To this aim, a fixed single scattering nozzle was modeled in the GATE platform. To accelerate the GATE simulations, a variance reduction technique (VRT) was also incorporated by ignoring the tracking of the secondary particles having a range below a predefined cutoff. In addition, the influence of collimator material on the model performance was evaluated. Beam uniformity,...

Development and validation of an optimal GATE model for double scattering proton beam delivery

, Article Journal of Instrumentation ; Volume 16, Issue 2 , 2021 ; 17480221 (ISSN) Piruzan, E ; Vosoughi, N ; Mahani, H ; Sharif University of Technology

IOP Publishing Ltd 2021

Abstract

Proton therapy (PT) is an emerging external beam radiation therapy characterized by superior dose distribution compared to conventional modalities. In the present study, an optimal GATE model was developed and then validated for a double scattering proton nozzle based on the previously constructed model. To this aim, a double scattering treatment nozzle was modeled in the GATE platform. To accelerate the GATE simulations, a virtual range modulation wheel (vRMW) and a variance reduction technique (VRT) were implemented. Proton beam flatness, symmetry, and delivery efficiency, secondary neutron dose, and dosimetric performance were characterized through a set of GATE simulations. The findings...

A comprehensive survey of proton beam therapy research and development in Iran

, Article Frontiers in Biomedical Technologies ; Volume 8, Issue 1 , 2021 , Pages 9-19 ; 23455829 (ISSN) Piruzan, E ; Vosoughi, N ; Mahani, H ; Sharif University of Technology

Tehran University of Medical Sciences 2021

Abstract

Purpose: Proton Beam Therapy (PBT) is an emerging radiotherapy technique using beams of proton to treat cancer. As the first report addressing the topic, the principal aim is to highlight the present status of PBT research and development in Iran as a developing country. Materials and Methods: To do so, the demand for PBT in Iran and Iran National Ion Therapy Center (IRNitc) was investigated and introduced. Then, Scopus and PubMed were searched for studies that dealt with PBT research in Iran and subsequently 6 major subfields of interest were identified. Furthermore, international collaborations were extracted from the bibliographic data. To combine both research and development sides, a...

Modeling and optimization of respiratory-gated partial breast irradiation with proton beams - A Monte Carlo study

, Article Computers in Biology and Medicine ; Volume 147 , 2022 ; 00104825 (ISSN) Piruzan, E ; Vosoughi, N ; Mahani, H ; Sharif University of Technology

Elsevier Ltd 2022

Abstract

The selection of a suitable duty factor (DF) remains a major challenge in respiratory-gated treatments. Therefore, this study aims at presenting a new methodology for fast optimizing the gating window width (duty factor (DF)) in respiratory-gated proton partial breast irradiation (PBI). To do so, GATE Monte Carlo simulations were performed for various target sizes and locations in supine and prone positions. Three different duty factors of 20, 25, and 33% were considered. Sparing factors (SF) for four organs-at-risk (OARs) were then assessed. The weighted-sum method was employed to search for an optimal DF. The results indicate that an SF higher than unity was obtained for all plans. The SF...

Identifying and Rating Indicators for Measuring Iranian Entrepreneurship Ecosystem based on OECD Framework’s Domains with ANDE Method

, M.Sc. Thesis Sharif University of Technology Barati, Amir (Author) ; Yavari, Elham (Supervisor) ; Sharif, Hossein (Co-Advisor)

Abstract

“Entrepreneurship ecosystem” is defined as the elements – individuals, organizations or institutions – apart from the individual entrepreneur that are conducive to, or inhibitive of, the choice of a person to become an entrepreneur, or the probabilities of his or her success following launch. Entrepreneurial businesses operate locally or regionally and are therefore subject to local or regional contextual influence. Moreover particularly in larger countries there can exist significant variation in industry structure and economic base across regions, emphasizing the importance of regional focus. Adopting appropriate policies at the regional level need to have a deep and accurate...

A Method for Incremental Learning of Stream Data

, Ph.D. Dissertation Sharif University of Technology Kashani, Elham Sadat (Author) ; Bagheri Shouraki, Saeed (Supervisor)

Abstract

Today, the pace of information generation, fast processing and instant decision-making is increasing. In this regard, one of the main needs in the field of data management and processing is stream data processing. Today's world needs new methods to deal with and analyze these data. Two of the most challenging aspects of data streams are (i) concept drift, i.e. evolution of data stream over time, which requires the ability to make timely decisions against the high speed of receiving new data; (ii) limited memory storage and the impracticality of using memory due to the large amount of data. Clustering is one of the common methods for processing data streams, without having basic knowledge...

Modeling and Optimization of Respiratory-Gated Proton Therapy for Breast Cancer Using Monte Carlo Simulation

, Ph.D. Dissertation Sharif University of Technology Piruzan, Elham (Author) ; Vosoughi, Naser (Supervisor) ; Mahani, Hojjatollah (Supervisor)

Abstract

Breast cancer is the most common cancer among women and has a growing rate. A combination of the proton beam and Accelerated partial breast irradiation (APBI) strategy can be effective in the case of the respiratory-induced target motion for breast cancer treatment. Due to the proximity of breast tissue to the two critical organ at risks (OARs) such as the lungs and heart, breast cancer proton therapy requires special considerations. The use of proton therapy with respiratory considerations (respiratory-gated), although a powerful way to control the mobile targets in breast cancer proton therapy, but needs to be optimized and improved as much as efficiency.The simulation and modeling of the...

Winner Strategies in a Simulated Stock Market

, Ph.D. Dissertation Sharif University of Technology Taherizadeh, Ali (Author) ; Zamani, Shiva (Supervisor) ; Yavari, Elham (Supervisor)

Abstract

In this study, we explore the dynamics of the stock market using an agent-based simulation platform. Our approach involves creating a multi-strategy market where each agent considers both fundamental and technical factors when determining their strategy. The agents vary in their approach to these factors and the time interval they use for technical analysis. Our findings indicate that investing heavily in reducing the value–price gap was a successful strategy, even in markets where there were no trading forces to reduce this gap. Furthermore, our results remain consistent across various modifications to the simulation’s structure

Applying Gamification in Corporate Entrepreneurship Culture, Specially Missionary Organizations; Through SafirFilm Case Study

, M.Sc. Thesis Sharif University of Technology Jafarian, Hamid Reza (Author) ; Yavari, Elham (Supervisor) ; Banki, Sara ($item.subfieldsMap.e)

Abstract

Although existing literature on organizational culture and its change process contains meaningful and rich theories but our studies show that there is no perfect and detailed framework on linking organizational culture change and corporate entrepreneurship culture. In addition to that, Gamification –defined as taking the game design elements into non-game contexts– is a fruitful and academically rich research area. Fortunately an idea proposed recently to explain a method for enhancements in organizational culture in general, and in corporate entrepreneurship culture in particularby Yavari and Jafarian based on using game mechanisms. In their paper "A Gamification-Based Method for Corporate...

Target motion management in breast cancer radiation therapy

, Article Radiology and Oncology ; Volume 55, Issue 4 , 2021 , Pages 393-408 ; 13182099 (ISSN) Piruzan, E ; Vosoughi, N ; Mahdavi, S. R ; Khalafi, L ; Mahani, H ; Sharif University of Technology

Sciendo 2021

Abstract

Background: Over the last two decades, breast cancer remains the main cause of cancer deaths in women. To treat this type of cancer, radiation therapy (RT) has proved to be efficient. RT for breast cancer is, however, challenged by intrafractional motion caused by respiration. The problem is more severe for the left-sided breast cancer due to the proximity to the heart as an organ-at-risk. While particle therapy results in superior dose characteristics than conventional RT, due to the physics of particle interactions in the body, particle therapy is more sensitive to target motion. Conclusions: This review highlights current and emerging strategies for the management of intrafractional...

Simulation and Evaluation of Dosimetric Parameters of 125I Thermobrachytherapy Source with Ferromagnetic Core

, M.Sc. Thesis Sharif University of Technology Soleymanpoor, Mohammad (Author) ; Hosseini, Abolfazl (Supervisor) ; Sheibani, Shahab (Supervisor) ; Poorbaygi, Hossein (Co-Supervisor) ; Mohagheghpour, Elham (Co-Supervisor)

Abstract

In the method treatment of thermobrachytherapy, the method of this project, simultaneously use of two processes of thermotherapy and brachytherapy is considered, which can be a more effective treatment for the destruction of tumor tissue. In thermotherapy, the temperature of the tissue is artificially raised to a temperature that leads to cell dysfunction resulting in cell death. In brachytherapy, the destruction of defective tissue is done by placing a source in the tissue. In the present project, we supposed to consider both mechanisms simultaneously for treatment at the same time. In this project, radioactive material 125I is used as a source of radiation emission for brachytherapy. In...