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- Title
- A MONTE CARLO STUDY OF THE NEUTRON AMBIENT DOSE EQUIVALENT FROM A PROTON PENCIL BEAM MEDICAL THERAPY UNIT.
- Creator
- Llanes, Alejandro Rene Lopez, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Proton Therapy, an effective cancer treatment, poses unintended consequences for patients and personnel due to secondary neutron production. This study investigates neutron attenuation in shielding materials like concrete using Monte Carlo (MC) simulations to optimize shielding requirements. Experimental limitations, such as detector sensitivity, energy range response, and spatial resolution, lead to inaccurate evaluations. MC simulations address that by modeling radiation transport and...
Show moreProton Therapy, an effective cancer treatment, poses unintended consequences for patients and personnel due to secondary neutron production. This study investigates neutron attenuation in shielding materials like concrete using Monte Carlo (MC) simulations to optimize shielding requirements. Experimental limitations, such as detector sensitivity, energy range response, and spatial resolution, lead to inaccurate evaluations. MC simulations address that by modeling radiation transport and neutron interactions with shielding materials. The TOPAS-MC code simulated secondary neutrons generated by a 226.5 MeV energy proton beam on a 30 cm diameter tissue-equivalent target. The target was placed in a 200 cm spherical concrete shell with a 100 cm inner radius and 2.3 g/cm3 density. Energy deposition and particle fluence were scored in 20 radial points across 18 angular positions, and the mean value per particle was estimated. Neutron fluence to ambient dose equivalent conversion coefficients from ICRU Report No. 95 were used to calculate the total dose equivalent values, which were scaled based on distance and concrete shield thickness.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014213
- Subject Headings
- Proton Therapy, Monte Carlo simulation, Neutrons
- Format
- Document (PDF)
- Title
- COMPARATIVE PHARMACOKINETICS, BIODISTRIBUTION AND DOSIMETRY OF 212Pb (ALPHA-EMITTER) LABELED ANTIBODY VS PEPTIDE VS SMALL MOLECULE.
- Creator
- Moshiri, Nader Sedeh, Leventouri, Theodora, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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With the advent of newly and more reliably designed targeted therapy methods in the past several years, targeted radionuclide therapy has attracted more attentions around the world as a more reliable treatment modality in combination with other well established traditional cancer treatments i.e., external beam radiotherapy and chemotherapy. Alpha particles have a high relative biological effectiveness (RBE) due to their high linear energy transfer (LET). However, to utilize them for...
Show moreWith the advent of newly and more reliably designed targeted therapy methods in the past several years, targeted radionuclide therapy has attracted more attentions around the world as a more reliable treatment modality in combination with other well established traditional cancer treatments i.e., external beam radiotherapy and chemotherapy. Alpha particles have a high relative biological effectiveness (RBE) due to their high linear energy transfer (LET). However, to utilize them for therapeutic purposes, precise human body dosimetry calculation is required. The measurement of their uptake and biodistribution can be quite challenging. Also, due to the complex biology of different types of cells, their shapes and functions, there is not a simple and clear understanding of the mechanism of action that fits all. This study aims to estimate and compare the human organ dosimetry of the alpha emitter, 212Pb, from animal data assuming that it is conjugated with three different types of commonly used targeting nanoparticles. For this purpose, the pre-published animal data of three different radionuclide labeled peptide, antibody, and small molecule carriers were selected and converted to human data. Then a compartmental model was designed for each of them to fit the model to the human data with 212Pb, half-life of 10.64 hours. Once each model reached the desired fit, the area under the curves were extracted then the estimated human organ dosimetry calculations took place via the MIRD scheme. The organ dosimetry results for 212Pb + three different carriers are presented in Tables 14, 17, and 20.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014215
- Subject Headings
- Cancer--Treatment, Lead-212, Nuclear Medicine
- Format
- Document (PDF)
- Title
- ON THE PARAXIAL APPROXIMATION IN QUANTUM OPTICS.
- Creator
- Jongewaard, Maria Fernanda de Boer, Beetle, Christopher, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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We examine how best to associate quantum states of a single particle to modes of a narrowly collimated beam of classical radiation modeled in the paraxial approximation, both for scalar particles and for photons. Our analysis stresses the importance of the relationship between the inner product used to define orthogonal modes of the paraxial beam, on the one hand, and the inner product underlying the statistical interpretation of the quantum theory, on the other. While several candidates for...
Show moreWe examine how best to associate quantum states of a single particle to modes of a narrowly collimated beam of classical radiation modeled in the paraxial approximation, both for scalar particles and for photons. Our analysis stresses the importance of the relationship between the inner product used to define orthogonal modes of the paraxial beam, on the one hand, and the inner product underlying the statistical interpretation of the quantum theory, on the other. While several candidates for such an association have been proposed in the literature, we argue that one of them is uniquely well suited to the task. Specifically, the mapping from beam modes to ”henochromatic” fields on spacetime is unique within a large class of similar mappings in that it is unitary in a mathematically precise sense. We also show that the single-particle quantum states associated to the orthogonal modes of a classical beam in the henochromatic approach are not only orthogonal, but also complete in the quantum Hilbert space.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014212
- Subject Headings
- Quantum optics, Hilbert space, Quantum theory
- Format
- Document (PDF)
- Title
- NON-RADIOACTIVE ELEMENTS FOR PROMPT GAMMA ENHANCEMENT IN PROTON THERAPY.
- Creator
- Galanakou, Panagiota, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Intensity modulated proton beam scanning therapy allows for highly conformal dose distribution and better sparing of organ-at-risk compared to conventional photon radiotherapy, thanks to the characteristic dose deposition at depth, the Bragg Peak (BP), of protons as a function of depth and energy. However, proton range uncertainties lead to extended clinical margins, at the expense of treatment quality. Prompt Gamma (PG) rays emitted during non- elastic interactions of proton with the matter...
Show moreIntensity modulated proton beam scanning therapy allows for highly conformal dose distribution and better sparing of organ-at-risk compared to conventional photon radiotherapy, thanks to the characteristic dose deposition at depth, the Bragg Peak (BP), of protons as a function of depth and energy. However, proton range uncertainties lead to extended clinical margins, at the expense of treatment quality. Prompt Gamma (PG) rays emitted during non- elastic interactions of proton with the matter have been proposed for in-vivo proton range tracking. Nevertheless, poor PG statistics downgrade the potential of the clinical implementation of the proposed techniques. We study the insertion of the nonradioactive elements 19F, 17O, 127I in a tumor area to enhance the PG production of 4.44 MeV (P1) and 6.15 MeV (P2) PG rays emitted during proton irradiation, both correlated with the distal fall-off of the BP. We developed a novel Monte Carlo (MC) model using the TOPAS MC package. With this model, we simulated incident proton beams with energies of 75 MeV, 100 MeV and 200 MeV in co-centric cylindrical phantoms. The outer cylinder (scorer) was filled with water and the inner cylinder (simulating a tumor region inside water-equivalent body) was filled with water containing 0.1%–20% weight fractions of each of the tested elements.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014222
- Subject Headings
- Proton Therapy, Monte Carlo method--Simulation, Gamma rays
- Format
- Document (PDF)
- Title
- A New Mechanical and Radiation Isocenter Adjustment Approach Using the Isopoint.
- Creator
- Irons, Tristan, Kyriacou, Andreas, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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The Winston-Lutz has been the standard test for isocenter convergence, however, any adjustments needed – in case the test fails – are time consuming since the source of error is not readily available from the results. Isopoint by the Aktina Medical company has been developed to address this problem via decoupling the mechanical from the radiation isocenter and providing the user with information that was inaccessible before. The focus of this research is to perform optimization of the...
Show moreThe Winston-Lutz has been the standard test for isocenter convergence, however, any adjustments needed – in case the test fails – are time consuming since the source of error is not readily available from the results. Isopoint by the Aktina Medical company has been developed to address this problem via decoupling the mechanical from the radiation isocenter and providing the user with information that was inaccessible before. The focus of this research is to perform optimization of the isocenter by using the Isopoint and to confirm the validity of its results, as well as to find how much time is saved via this new technology. The data for this project was collected on a 2012 Elekta Synergy, a Varian 21ix, and a 2021 Elekta Versa through partnership with GenesisCare. Our findings indicate that the Isopoint will allow for more accurate and speedy adjustments of the LINAC (Linear Accelerator) and will be integral in the future of this field.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014259
- Subject Headings
- Medical physics
- Format
- Document (PDF)
- Title
- Microfluidic Electrical Impedance Spectroscopy for Blood Analysis.
- Creator
- Rikhtehgaran, Samaneh, Wille, Luc T., Du, E., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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The study of the electrical properties of red blood cells (RBCs) plays a crucial role in advancing our understanding of human health. As RBCs age, they undergo changes that affect hemorheology and blood microcirculation, which have far-reaching implications for disease research. Furthermore, the shortage of RBC storage units can be a major issue for patients, underscoring the importance of characterizing RBC aging with respect to cell densities. In individuals with abnormal hemoglobin disease...
Show moreThe study of the electrical properties of red blood cells (RBCs) plays a crucial role in advancing our understanding of human health. As RBCs age, they undergo changes that affect hemorheology and blood microcirculation, which have far-reaching implications for disease research. Furthermore, the shortage of RBC storage units can be a major issue for patients, underscoring the importance of characterizing RBC aging with respect to cell densities. In individuals with abnormal hemoglobin disease, alterations in hemoglobin and its functionality can modify the volume and density of RBCs, making their study even more crucial. To this end, our aim is to investigate the impedance alterations of RBCs after distributing them into different layers based on their densities. We have developed a novel method for non-invasive, rapid, and real-time single-cell analysis of RBCs. Our approach involves the use of electrical impedance spectroscopy (EIS) to study the cells after performing cell fractionation. Our studies indicate an increasing trend for RBC resistance and a decreasing trend for the cell membrane as the density of the layer increases. Additionally, we have developed a method for extracting hemoglobin with high purity from fresh samples of RBCs. By passing lysed RBCs through ultrafiltration devices and removing debris and membranes, we were able to isolate hemoglobin. Using the EIS technique, we studied the alterations of impedance over a frequency range, obtaining valuable insight into the electrical properties of hemoglobin.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014223
- Subject Headings
- Blood--Analysis, Erythrocytes--Aging, Hemorheology, Electrical impedance spectroscopy, Microfluidics
- Format
- Document (PDF)
- Title
- AN IMPROVED NEUTRINO TRANSPORT ALGORITHM FOR THE CHIMERA SUPERNOVA CODE.
- Creator
- Tejedor, Ruben Dario, Bruenn, Stephen W., Tichy, Wolfgang, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Core-Collapse Supernovae (CCSNe) are some of the most powerful events in the universe liberating an astonishing 3×1053 ergs of the gravitational binding energy released by the collapse of the stellar core to a nascent neutron star (PNS) that is formed in these events. The visible display is capable of outshining the entire galaxy where it inhabits. Most of this energy, ~ 99%, is carried away by neutrinos of all flavors, however. According to the favored theory of CCSNe, the production and...
Show moreCore-Collapse Supernovae (CCSNe) are some of the most powerful events in the universe liberating an astonishing 3×1053 ergs of the gravitational binding energy released by the collapse of the stellar core to a nascent neutron star (PNS) that is formed in these events. The visible display is capable of outshining the entire galaxy where it inhabits. Most of this energy, ~ 99%, is carried away by neutrinos of all flavors, however. According to the favored theory of CCSNe, the production and transport of neutrinos from the dense core through the less dense mantle is believed to deposit energy in the mantle and thereby initiate the supernova explosion. Numerically modeling these events realistically to validate the model therefore requires an accurate neutrino transport algorithm coupled to sophisticated neutrino microphysics to compute the emission, transport, and energy deposition of neutrinos. The CHIMERA code is a radiation-hydrodynamics code that has been developed to numerically model CCSNe in multiple spatial dimensions. The neutrino transport algorithm currently incorporated in CHIMERA is based upon the Multigroup Flux-Limited Diffusion (MGFLD) method. This current method basically uses only the zeroth angular moment of the Boltzmann equation and closes the system with terms dropped from the first angular moment to produce a diffusion-like equation. A flux-limiter is added to interpolate between the diffusive and free-streaming regimes, and to prevent the algorithm from computing acausal, i.e., faster than light transport, in regions where the neutrino mean free paths are large.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014293
- Subject Headings
- Supernovae, Neutrinos, Astrophysics
- Format
- Document (PDF)
- Title
- pH Dynamics within the Drosophila Synaptic Cleft During Activity.
- Creator
- Feghhi, Touhid, Lau, Andy W.C., Macleod, Gregory T., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Acute pH sensitivity of many neural mechanisms highlights the vulnerability of neurotransmission to the pH of the extracellular milieu. The dogma is that the synaptic cleft will acidify upon neurotransmission because the synaptic vesicles corelease neurotransmitters and protons to the cleft, and the direct data from sensory ribbon-type synapses support the acidification of the cleft. However, ribbon synapses have a much higher release probability than conventional synapses, and it’s not...
Show moreAcute pH sensitivity of many neural mechanisms highlights the vulnerability of neurotransmission to the pH of the extracellular milieu. The dogma is that the synaptic cleft will acidify upon neurotransmission because the synaptic vesicles corelease neurotransmitters and protons to the cleft, and the direct data from sensory ribbon-type synapses support the acidification of the cleft. However, ribbon synapses have a much higher release probability than conventional synapses, and it’s not established whether conventional synapses acidify as well. To test the acidification of the cleft in the conventional synapse, we used genetically encoded fluorescent pH reporters targeted to the synaptic cleft of Drosophila larvae. We observed alkalinization rather than acidification during activity, and this alkalinization was dependent on the exchange of protons for calcium at the postsynaptic membrane. A reaction-diffusion computational model of the pH dynamics at the Drosophila larval neuromuscular junction was developed to leverage the experimental data. The model incorporates the release of glutamate, ATP, and protons from synaptic vesicles into the cleft, PMCA activity, bicarbonate, and phosphate buffering systems. By means of numerical simulations, we reveal a highly dynamic pH landscape within the synaptic cleft, harboring deep but exceedingly rapid acid transients that give way to a prolonged period of alkalinization.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014221
- Subject Headings
- Synapses, pH (Chemistry), Hydrogen-ion concentration., Synaptic Transmission, Drosophila
- Format
- Document (PDF)
- Title
- Dosimetric Influence of Dose due to the PTV Dose Uniformity on the Critical Organs.
- Creator
- Yigit, Erdem, Pella, Silvia, Theodora Leventouri, Theodora Leventouri,, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Dose uniformity in the Planning Target Volume (PTV) can induce a higher-than-expected dose distribution in the nearby critical organs. The goal of this study is to evaluate the influence of the Planning Target volume dose uniformity on the surrounding critical organs (OAR). Ten cases of anonymized patients’ data were selected for our study including: Breast cancer, Brain cancer, Head and Neck cancer, Lung and Prostate calculations of Conformity indices, Biological Effective Doses (BED), Tumor...
Show moreDose uniformity in the Planning Target Volume (PTV) can induce a higher-than-expected dose distribution in the nearby critical organs. The goal of this study is to evaluate the influence of the Planning Target volume dose uniformity on the surrounding critical organs (OAR). Ten cases of anonymized patients’ data were selected for our study including: Breast cancer, Brain cancer, Head and Neck cancer, Lung and Prostate calculations of Conformity indices, Biological Effective Doses (BED), Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) were used to calculate the dose distribution in PTV as well as the dose delivered to the surrounding critical organs of each PTV. We assume that the tumors PTVs have homogeneous density as well as the surrounding normal tissue. Conformity indices (CI) for Breast (PTV) are between 1.8 – 1.9, for Brain (PTV) are between 1.6 – 2.0, for Lungs are 1.5 – 1.6, for Prostate are between 0.4 – 0.5, for Head and Neck are 0.3 – 0.4. Dose uniformity in all the PTVs is 1.089 which is a good indication of the quality of treatment delivered to the tumor. TCP is averaging of value of 87.94 and NTCP is 3.4445.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014339
- Subject Headings
- Radiation dosimetry, Biophysics, Cancer
- Format
- Document (PDF)
- Title
- NOVEL RHEOTAXIS-BASED MICROFLUIDIC DEVICES FOR SORTING HUMAN SPERM.
- Creator
- Ataei, Afrouz, Lau, Andy W.C., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
The ultimate challenge for assisted reproductive technologies (ARTs) is to select the most competent sperm population from a semen sample in an efficient way. In this thesis, we report on an effective sperm sorting microfluidic device that exploits the rheotaxis of sperm and investigates the sperm quality sorted under various flow conditions. Rheotaxis is the ability of a sperm cell to orient itself in the direction of the flow and swim against it. We developed a novel passively driven...
Show moreThe ultimate challenge for assisted reproductive technologies (ARTs) is to select the most competent sperm population from a semen sample in an efficient way. In this thesis, we report on an effective sperm sorting microfluidic device that exploits the rheotaxis of sperm and investigates the sperm quality sorted under various flow conditions. Rheotaxis is the ability of a sperm cell to orient itself in the direction of the flow and swim against it. We developed a novel passively driven pumping system that provides a steady flow rate while it requires no external power source. We have also developed another rheotaxis-based microfluidic device that washes out the raw semen sample from any dead or less motile sperm. The device consists of a collection and waste chamber. To evaluate the effect of the shape and height of the collection chamber, we measured the sperm motility and velocity parameters after sorting using varying the shape and height of the collection chamber. We demonstrated that sperm selected with all devices have higher motility, normal morphology, and a fewer degree of DNA fragmentation compared to a control group.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013971
- Subject Headings
- Microfluidic devices, Rheotaxis, Spermatozoa, Reproductive Techniques, Assisted
- Format
- Document (PDF)
- Title
- ELLIPTICA: A NEW PSEUDOSPECTRAL CODE FOR THE CONSTRUCTION OF INITIAL DATA.
- Creator
- Rashti, Alireza, Tichy, Wolfgang, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Unveiling the secrets of gravity necessitates numerical relativity simulations of gravitational systems, as observations made by gravitational wave detectors expect an interpretation. In the other hand, these numerical simulations require physical and constraint-satisfying initial data. Therefore, the accuracy of simulations go hand in hand with the accuracy of initial data. As such, constructing accurate initial data is an indispensable task and it is the very subject of this dissertation....
Show moreUnveiling the secrets of gravity necessitates numerical relativity simulations of gravitational systems, as observations made by gravitational wave detectors expect an interpretation. In the other hand, these numerical simulations require physical and constraint-satisfying initial data. Therefore, the accuracy of simulations go hand in hand with the accuracy of initial data. As such, constructing accurate initial data is an indispensable task and it is the very subject of this dissertation. Here, we present the newly developed pseudospectral code Elliptica, an infrastructure for construction of initial data for various binary and single gravitational systems of all kinds. The elliptic equations under consideration are solved on a single spatial hypersurface of the spacetime manifold. Using coordinate maps, the hypersurface is covered by patches whose boundaries can adapt to the surface of the compact objects. To solve elliptic equations with arbitrary boundary condition, Elliptica deploys a Schur complement domain decomposition method with a direct solver. In this version, we use cubed sphere coordinate maps and the fields are expanded using Chebyshev polynomials of the first kind. Here, we explain the building blocks of Elliptica and the initial data construction algorithm for black hole-neutron star binary systems. We perform convergence tests and evolve the data to validate our results. Within our framework, the neutron star can reach spin values close to breakup with arbitrary direction, while the black hole can have arbitrary spin with dimensionless spin magnitude ~ 0.8.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014006
- Subject Headings
- Gravitational waves, Elliptic functions, Neutron stars, Black holes (Astronomy)
- Format
- Document (PDF)
- Title
- An Algorithm to Determine IMRT Optimization Parameters within the Elekta Monaco® Treatment Planning System that Increases Dose Homogeneity and Dose Conformity in the Planning Target Volume.
- Creator
- Gregorisch, David, Pella, Silvia, Kyriacou, Andreas, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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An algorithm to determine IMRT optimization parameters within the Elekta Monaco® treatment planning system that increases dose homogeneity and dose conformity in the planning target volume was developed. This algorithm determines IMRT optimization parameters by calculating the difference between two pairs of dose points along the target volume’s dose volume histogram: Dmax – Dmin, and D2 – D98. The algorithm was tested on the Elekta Monaco® Treatment Planning System at GenesisCare of Coconut...
Show moreAn algorithm to determine IMRT optimization parameters within the Elekta Monaco® treatment planning system that increases dose homogeneity and dose conformity in the planning target volume was developed. This algorithm determines IMRT optimization parameters by calculating the difference between two pairs of dose points along the target volume’s dose volume histogram: Dmax – Dmin, and D2 – D98. The algorithm was tested on the Elekta Monaco® Treatment Planning System at GenesisCare of Coconut Creek, Florida using CT data from 10 anonymized patients with non-small cell lung cancer of various tumor sizes and locations. Nine iterations of parameters were tested on each patient. Once the ideal parameters were found, the results were evaluated using the ICRU report 83 homogeneity index as well as the Paddick conformity index. As an outcome of this research, it is recommended that at least three iterations of IMRT optimization parameters should be calculated to find the ideal parameters.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013990
- Subject Headings
- Radiotherapy, Algorithm, Medical physics
- Format
- Document (PDF)
- Title
- Prediction of Radiobiological Indices and Equivalent Uniform Dose in Lung Cancer Radiation Therapy using an Artificial Neural Network.
- Creator
- Pudasaini, Mukunda Prasad, Leventouri, Theodora, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
In radiotherapy, radiobiological indices tumor control probability (TCP), normal tissue complication probability (NTCP), and equivalent uniform dose (EUD) are computed by analytical models. These models are rarely employed to rank and optimize treatment plans even though radiobiological indices weights more compared to dosimetric indices to reflect treatment goal. The objective of this study is to predict TCP, NTCP and EUDs for lung cancer radiotherapy treatment plans using an artificial...
Show moreIn radiotherapy, radiobiological indices tumor control probability (TCP), normal tissue complication probability (NTCP), and equivalent uniform dose (EUD) are computed by analytical models. These models are rarely employed to rank and optimize treatment plans even though radiobiological indices weights more compared to dosimetric indices to reflect treatment goal. The objective of this study is to predict TCP, NTCP and EUDs for lung cancer radiotherapy treatment plans using an artificial neural network (ANN). A total of 100 lung cancer patients’ treatment plans were selected for this study. Normal tissue complication probability (NTCP) of organs at risk (OARs) i.e., esophagus, spinal cord, heart and contralateral lung and tumor control probability (TCP) of treatment target volume (i.e., tumor) were calculated by the equivalent uniform dose (EUD) model. TCP/NTCP pairing with corresponding EUD are used individually as outputs for the neural network. The inputs for ANN are planning target volume (PTV), treatment modality, tumor location, prescribed dose, number of fractions, mean dose to PTV, gender, age, and mean doses to the OARs. The ANN is based on Levenberg-Marquardt algorithm with one hidden layer having 13 inputs and 2 outputs. 70% of the data was used for training, 15% for validation and 15% for testing the ANN. Our ANN model predicted TCP and EUD with correlation coefficient of 0.99 for training, 0.96 for validation, and 0.94 for testing. In NTCP and EUD prediction, averages of correlation coefficients are 0.94 for training, 0.89 for validation and 0.84 for testing. The maximum mean squared error (MSE) for the ANN is 0.025 in predicting the NTCP and EUD of heart. Our results show that an ANN model can be used with high discriminatory power to predict the radiobiological indices for lung cancer treatment plans.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014064
- Subject Headings
- Lungs--Cancer--Radiotherapy, Radiobiology, Neural networks (Computer science)
- Format
- Document (PDF)
- Title
- Radiation Induced Injury of Hepatocellular Carcinoma, IMRT vs SBRT.
- Creator
- Feghhi, Touhid, Pella, Silvia, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Hepatocellular carcinoma is currently one of the most fatal cancers in the world. The routine treatment for this type of cancer consists of surgery, chemotherapy, and finally radiation therapy. Recent advancements in technology have enabled us to deliver highly conformed dose to planning target volume. Two of these methods are Intensity modulated Radiation Therapy (IMRT) and Stereotactic Body Radiation Therapy (SBRT). The difference between these two methods is that in the SBRT high radiation...
Show moreHepatocellular carcinoma is currently one of the most fatal cancers in the world. The routine treatment for this type of cancer consists of surgery, chemotherapy, and finally radiation therapy. Recent advancements in technology have enabled us to deliver highly conformed dose to planning target volume. Two of these methods are Intensity modulated Radiation Therapy (IMRT) and Stereotactic Body Radiation Therapy (SBRT). The difference between these two methods is that in the SBRT high radiation dose per fraction is delivered, but smaller number of fractions which renders better tumor control probability. However, better tumor control comes at the price of complications and radiation induced liver damage. In this work, we compare the outcome of radiation with regards to the probability of radiation damage to the liver after IMRT and SBRT. For this purpose, we analyzed 10 anonymized patients’ data with liver cancer, and we made two similar treatment plans for them. The difference in two plans is dose per fraction and total dose. After optimizing the treatments and calculating the dose volume histogram, we found the effective volume of the liver being irradiated. Finally, this effective volume and the corresponding dose were used to show that SBRT has the advantage of better tumor control probability at the cost of higher probability of complications.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014070
- Subject Headings
- Carcinoma, Hepatocellular, Radiotherapy--Adverse effects, Radiotherapy, Intensity-Modulated, Stereotactic Body Radiation Therapy
- Format
- Document (PDF)
- Title
- DEVELOPMENT OF BROADBAND QUANTUM TECHNOLOGY AND OPTIMAL DISCRIMINATION OF QUANTUM CORRELATIONS.
- Creator
- Rezaei, Tahereh, Kwiat, Paul G., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
In this effort, we present progress toward demonstrating a Decoy-State Quantum Key Distribution (QKD) source based on a polarization-modulator and a wavelength-stable attenuated pulsed laser. A three-state QKD protocol is achieved by preparing particular quantum polarization states. The polarization-modulator-based QKD source improves security by removing several sources of side-channel attacks that exist when multiple sources are used to generate different QKD states. Here we present a QKD...
Show moreIn this effort, we present progress toward demonstrating a Decoy-State Quantum Key Distribution (QKD) source based on a polarization-modulator and a wavelength-stable attenuated pulsed laser. A three-state QKD protocol is achieved by preparing particular quantum polarization states. The polarization-modulator-based QKD source improves security by removing several sources of side-channel attacks that exist when multiple sources are used to generate different QKD states. Here we present a QKD source design and an evaluation of critical subsystems characterized by the Quantum Bit Error Rate, Quantum State tomography, and achievable Key Rates. The QKD source is intended to operate within compact Size, Weight, and Power constraints. The Polarization-Modulator QKD source has applications in future mobile quantum networks such as Unmanned-Aerial Vehicles (UAV) and autonomous vehicles, as well as fixed fiber-based quantum networks. Quantum mechanics can produce correlations that are stronger than classically allowed. This stronger-than-the-classical correlation is the “fuel” for quantum computing. In 1991 Schumacher forwarded a beautiful geometric approach, analogous to the well-known result of Bell, to capture the non-classicality of this correlation for a singlet state. He used well-established information distance defined on an ensemble of identically–prepared states. He calculated that for certain detector settings used to measure the entangled state, the resulting geometry violated a triangle inequality —a violation that is not possible classically. This provided novel information–based on geometric Bell inequality in terms of a “covariance distance.” Here we experimentally reproduce his construction and demonstrate a definitive violation for a Bell state of two photons based on the usual spontaneous parametric down-conversion in a paired BBO crystal. The state we produced had visibility of Vad = 0.970}0.012. We discuss generalizations to higher dimensional multipartite quantum states.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014102
- Subject Headings
- Quantum cryptography, Quantum optics, Quantum mechanics
- Format
- Document (PDF)
- Title
- A GEOMETRY OF ENTANGLEMENT.
- Creator
- Mostafanazhad, Shahabeddin Aslmarand, Wille, Luc T. Wille, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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We introduce a novel geometric approach to characterize entanglement relations in large quantum systems. Our approach is inspired by Schumacher’s singlet state triangle inequality, which used an entropic-based distance to capture the strange properties of entanglement using geometric-based inequalities. Schumacher uses classical entropy and can only describe the geometry of bipartite states. We extend his approach by using von Neumann entropy to create an entanglement monotone that can be...
Show moreWe introduce a novel geometric approach to characterize entanglement relations in large quantum systems. Our approach is inspired by Schumacher’s singlet state triangle inequality, which used an entropic-based distance to capture the strange properties of entanglement using geometric-based inequalities. Schumacher uses classical entropy and can only describe the geometry of bipartite states. We extend his approach by using von Neumann entropy to create an entanglement monotone that can be generalized for higher dimensional systems. We achieve this by utilizing recent definitions for entropic areas, volumes, and higher dimensional volumes for multipartite which we introduce in this thesis. This enables us to differentiate systems with high quantum correlation from systems with low quantum correlation and differentiate between different types of multi-partite entanglement. It also enable us to describe some of the strange properties of quantum entanglement using simple geometrical inequalities. Our geometrization of entanglement provides new insight into quantum entanglement. Perhaps by constructing well motivated geometrical structures (e.g. relations among areas, volumes ...), a set of trivial geometrical inequalities can reveal some of the complex properties of higher-dimensional entanglement in multi-partite systems. We provide numerous illustrative applications of this approach.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013912
- Subject Headings
- Quantum systems, Geometry, Quantum entanglement
- Format
- Document (PDF)
- Title
- COMPUTATIONAL ASPECTS OF QUANTUM GRAVITY: NUMERICAL METHODS IN SPINFOAM MODELS.
- Creator
- Qu, Dongxue, Han, Muxin, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Quantum Gravity attempts to unify general relativity (GR) and quantum theory, and is one of the challenging research areas in theoretical physics. LQG is a background-independent and non-perturbative approach towards the theory of quantum gravity. The spinfoam formulation gives the covariant path integral formulation of LQG. The spinfoam amplitude plays a crucial role in the spinfoam formulation by defining the transition amplitude of covariant LQG. It is particularly interesting for testing...
Show moreQuantum Gravity attempts to unify general relativity (GR) and quantum theory, and is one of the challenging research areas in theoretical physics. LQG is a background-independent and non-perturbative approach towards the theory of quantum gravity. The spinfoam formulation gives the covariant path integral formulation of LQG. The spinfoam amplitude plays a crucial role in the spinfoam formulation by defining the transition amplitude of covariant LQG. It is particularly interesting for testing the semiclassical consistency of LQG, because of the connection between the semiclassical approximation of path integral and the stationary phase approximation. The recent semiclassical analysis reveals the interesting relation between spinfoam amplitudes and the Regge calculus, which discretizes GR on triangulations. This relation makes the semiclassical consistency of covariant LQG promising. The spinfoam formulation also provides ways to study the n-point functions of quantum-geometry operators in LQG. Despite the novel and crucial analytic results in the spinfoam formulation, the computational complexity has been obstructed further explorations in spinfoam models. Nevertheless, numerical approaches to spinfoams open new windows to circumvent this obstruction. There has been enlightening progress on numerical computation of the spinfoam amplitudes and the two-point function. The numerical technology should expand the toolbox to investigate LQG.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013878
- Subject Headings
- Quantum gravity, Quantum theory, Quantum gravity--Mathematics, Theoretical physics
- Format
- Document (PDF)
- Title
- DETECTION AND CATEGORIZATION OF LUNG CANCER USING CONVOLUTIONAL NEURAL NETWORK.
- Creator
- Mostafanazhad, Shahabeddin Aslmarand, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Medical professionals use CT images to get information about the size, shape, and location of any lung nodules. This information will help radiologist and oncologist to identify the type of cancer and create a treatment plan. However, most of the time, the diagnosis regarding the types of lung cancer is error-prone and time-consuming. One way to address these problems is by using convolutional neural networks. In this Thesis, we developed a convolutional neural network that can detect...
Show moreMedical professionals use CT images to get information about the size, shape, and location of any lung nodules. This information will help radiologist and oncologist to identify the type of cancer and create a treatment plan. However, most of the time, the diagnosis regarding the types of lung cancer is error-prone and time-consuming. One way to address these problems is by using convolutional neural networks. In this Thesis, we developed a convolutional neural network that can detect abnormalities in lung CT scans and further categorize the abnormalities to benign, malignant adenocarcinoma and malignant squamous cell carcinoma. Our network is based on DenseNet, which utilizes dense connections between layers (dense blocks), so that all layers are connected. Because of all layers being connected, different layers can reuse features from previous layers which speeds up the process and make this network computationally efficient. To retrain this network we used CT images for 314 patients (over 1500 CT images) consistent of 42 Lung Adenocarcinoma and 78 Squamous Cell Carcinoma, 118 Non cancer and 76 benign were acquired from the National Lung Screening Trial (NLST). These images were divided to two categories of Training and Validation with 70% being training dataset and 30% as validation dataset. We trained our network on Training dataset and then checked the accuracy of our model using the validation dataset. Our model was able to categorize lung cancer with an accuracy of 88%. Afterwards we calculated the the confusion matrix, Precision (Sensitivity), Recall (Positivity) and F1 score of our model for each category. Our model is able to classify Normal CT images with Normal Accuracy of 89% Precision of 94% and F1 score of 93%. For benign nodules Accuracy was 92% precision of 97% and F1 score 86%, while for Adenocarcinoma and squamous cell cancer the Accuracy was 98% and 93%, Precision 85% and 84% and F1 score 92% and 86.9%. The relatively high accuracy of our model shows that convolutional neural networks can be a valuable tool for the classification of lung cancer, especially in a small city or underdeveloped rural hospital settings and can play a role in achieving healthcare equality.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013965
- Subject Headings
- Lungs--Cancer, Neural networks (Computer science), Tomography, X-Ray Computed
- Format
- Document (PDF)
- Title
- Efficacy of the virtual cone method using fixed small multi-leaf collimator field for stereotactic radiosurgery.
- Creator
- Neupane, Taindra, Leventouri, Theodora, Shang, Charles, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Dosimetric uncertainty in very small (
Show moreDosimetric uncertainty in very small (< 2 x 2 cm2) photon fields is notably higher that has created research questions when using small-field virtual cone with variable multileaf collimator (MLC) fields. We evaluate the efficacy of the virtual cone with a fixed MLC field for stereotactic radiosurgery (SRS) of small targets such as trigeminal neuralgia. We employed a virtual cone technique with a fixed field geometry, called fixed virtual cone (fVC), for small target radiosurgery using the EDGE (Varian Medical Systems, Palo Alto, CA) linac. The fVC is characterized by 0.5 cm x 0.5 cm high-definition MLC field of 10 MV flattening filter-free (FFF) beam defined at 100 cm SAD, while jaws are positioned at 1.5 cm x 1.5 cm. A spherical dose distribution equivalent to 5 mm cone was generated by using 10–14 non-coplanar partial arcs. The dosimetric accuracy of this technique was validated using the SRS MapCHECK (Sun Nuclear Corporation, FL) and the EBT3 (Ashland Inc., NJ) film based on absolute dose measurements. For the quality assurance (QA), 10 treatment plans for trigeminal neuralgia consisting of various arc fields at different collimator angles were analyzed retrospectively using 6 MV and 10 MV FFF beams, including the field-by-field study (n = 130 fields). Dose outputs were compared between the SRS MapCHECK measurements and Eclipse treatment planning system (TPS) with Acuros XB algorithm (version 16.1). In addition, important clinical parameters of 15 cases treated for trigeminal neuralgia were evaluated for the clinical performance. Moreover, dosimetric (field output factors, dose/MU) uncertainties considering a minute (± 0.5–1.0 mm) leaf shift in the field defining fVC, were examined from the TPS, SRS diode (PTW 60018) measurements, and Monte Carlo (MC) simulations.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013958
- Subject Headings
- Radiation dosimetry, Radiosurgery, Collimators (Optical instrument), Monte Carlo method
- Format
- Document (PDF)
- Title
- MODIFIED f(R) THEORY OF GRAVITY: AN ALTERNATIVE GRAVITY THEORY.
- Creator
- Saiedi, Hamidreza, Wille, Luc T., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Through the variational principle, we review the gravitational field equations in Einstein gravity and modified f(R) gravity theories. Metric and Palatini formalisms are two different approaches that are employed to obtain the field equations in the context of f(R) theory of gravity. In this framework, we attempt to investigate the energy conditions in Friedmann-Lemaitre-Robertson-Walker (FLRW) metric using the Raychaudhuri equation. Then, we focus on wormhole geometries and their...
Show moreThrough the variational principle, we review the gravitational field equations in Einstein gravity and modified f(R) gravity theories. Metric and Palatini formalisms are two different approaches that are employed to obtain the field equations in the context of f(R) theory of gravity. In this framework, we attempt to investigate the energy conditions in Friedmann-Lemaitre-Robertson-Walker (FLRW) metric using the Raychaudhuri equation. Then, we focus on wormhole geometries and their thermodynamics behavior in Palatini and metric versions of modified f(R) gravity, separately. To violate the null and the weak energy conditions, wormhole spacetimes need an exotic matter. It has been shown that in f(R) gravity the matter threading the wormholes serves the energy conditions, and it is the derivative terms of the higher order curvature that may be explained as a gravitational fluid, that supports these geometries. Therefore, in f(R) gravity theory it is not required to introduce exotic matter in order to have traversable wormholes. In the framework of metric and Palatini f(R) gravity, we investigate the thermodynamic properties of evolving wormholes. We obtain an expression for the variation of the total entropy to discuss the thermodynamic behavior of wormhole spacetimes. The investigation has been extended to the apparent and event horizons. Eventually, we apply the radius of these horizons to determine the validity of the generalized second law of thermodynamics. This law states that the rate of change of total entropy is positive.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013879
- Subject Headings
- Gravity, Gravitational fields--Mathematics, Wormholes (Physics)
- Format
- Document (PDF)