Current Search: Dosimetry (x)
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Title
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Optimization algorithms for intensity modulated radiation treatment.
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Creator
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Doozan, Brian, Leventouri, Theodora, Graduate College
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Date Issued
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2013-04-12
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PURL
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http://purl.flvc.org/fcla/dt/3361926
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Subject Headings
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Radiotherapy, Radiation dosimetry, Algorithms
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Format
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Document (PDF)
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Title
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Commissioning of 360⁰ Rotational Single Room ProBeam Compact™ (Varian Medical) Pencil Beam Scanning Proton Therapy System.
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Creator
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Fathallah, Shreen Mohamed, Shang, Charles, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
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Abstract/Description
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A clinical commissioning of the first 360 rotational compact Varian ProBeam scanning proton pencil beam (Varian Medical, Palo Alto, CA) system was conducted at the South Florida Proton Therapy Institute (SFPTI). The beam dosimetry and characterizations were the vital section used to verify the consistency of the treatment planning system (TPS) outputs. The integrated depth dose curves were acquired with AP CAX in water phantom utilizing a large PTW Bragg peak chamber; the dose output factors...
Show moreA clinical commissioning of the first 360 rotational compact Varian ProBeam scanning proton pencil beam (Varian Medical, Palo Alto, CA) system was conducted at the South Florida Proton Therapy Institute (SFPTI). The beam dosimetry and characterizations were the vital section used to verify the consistency of the treatment planning system (TPS) outputs. The integrated depth dose curves were acquired with AP CAX in water phantom utilizing a large PTW Bragg peak chamber; the dose output factors measurements were performed by using IBA PCC05 chamber at 1.5 cm water depth applying a single layer 10×10 cm2 beams and 1.1 RBE offset as recommended in TRS 398 report. Widths of the Bragg peaks ranges (Rb80-Ra80) were from 4.07 cm to 30.51 cm for the energy range 70 MeV to 220 MeV. Beam optics such as spot sizes and spot profiles were acquired in-air by using Logos scintillators with a CCD camera and the result data were from 2.33 mm to for 77 MeV to 9.70 mm for 220 MeV. In different field sizes, a comparison between the dose measured using PTW Semiflex and the AcurosPT estimated dose were performed to study the halo effect. All the measured dosimetric parameters showed that the design specifications were well achieved, and the results are suitable for being used as a part of the clinical commissioning and quality assurance program for treating patients.
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Date Issued
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2021
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PURL
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http://purl.flvc.org/fau/fd/FA00013691
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Subject Headings
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Proton Therapy, Dosimetry
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Format
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Document (PDF)
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Title
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Dosimetric Influence of Dose due to the PTV Dose Uniformity on the Critical Organs.
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Creator
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Yigit, Erdem, Pella, Silvia, Theodora Leventouri, Theodora Leventouri,, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
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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.
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Date Issued
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2023
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PURL
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http://purl.flvc.org/fau/fd/FA00014339
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Subject Headings
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Radiation dosimetry, Biophysics, Cancer
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Format
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Document (PDF)
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Title
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Improved Methodology of Static HDMLC Virtual Cone based Rapid Arcs for Stereotactic Ablative Radiotherapy.
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Creator
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Stevens, Ryan, Shang, Charles, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
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Abstract/Description
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Physical cones equipped on GammaKnife, Cyberknife, and C-arm linacs have been the standard practice in Stereotactic Ablative Radiotherapy (SART) for small intracranial lesions, such as treating trigeminal or glossopharyngeal neuralgia targets. The advancement of high-definition multi-leaf collimators (HDMLC), treatment planning systems, and small field dosimetry now allows for treatment without the need for an auxiliary mounted physical cone. This treatment type uses the “virtual cone”, a...
Show morePhysical cones equipped on GammaKnife, Cyberknife, and C-arm linacs have been the standard practice in Stereotactic Ablative Radiotherapy (SART) for small intracranial lesions, such as treating trigeminal or glossopharyngeal neuralgia targets. The advancement of high-definition multi-leaf collimators (HDMLC), treatment planning systems, and small field dosimetry now allows for treatment without the need for an auxiliary mounted physical cone. This treatment type uses the “virtual cone”, a permanent high-definition MLC, arrangement to deliver “very small fields” with comparable spherical dose distributions to physical cones. The virtual cone therapy, on a Varian Edge™ linac using multiple non-coplanar arcs with static HDMLCs, is a comparable technique that can be used to treat small intracranial neuralgia or other small lesions. In this investigation, two flattening filter free (FFF) photon beams, 6MV FFF and 10MV FFF, were tested for optimal delivery and safety conditions for treating intracranial lesions. The virtual cone method on a Varian Edge™ Linear accelerator using rapid arc stereotactic radiosurgery was used to treat cranial neuralgia for chronic pain for six patients. Absolute dose, relative dose measurements, and monitor units were the main characteristics that were examined to decide which energy was the best for treatment. Source-to-axis distances (SAD) of 100cm measurements were taken at depths of 10cm and 5cm, respectively.
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Date Issued
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2020
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PURL
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http://purl.flvc.org/fau/fd/FA00013630
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Subject Headings
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Radiotherapy, Radiation dosimetry, Stereotaxic Techniques
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Format
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Document (PDF)
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Title
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A Comparative Analysis of Monte Carlo and Collapsed Cone Dose Calculation Algorithms for Monaco 3D Treatment Plans.
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Creator
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Pereira, Shakeel, Kyriacou, Andreas, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
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Abstract/Description
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The Monaco treatment planning system offers three different dose calculation algorithms for use in calculating 3D treatment plans. These include Monte Carlo (MC), Collapsed Cone (CC) and the pencil beam algorithms. The aim of this study is an in-depth analysis of Monte Carlo and Collapsed Cone dose calculation methods to find the optimal parameters for clinical use for both algorithms. An end-to-end phantom with inhomogeneities was scanned and the DICOM images were imported into Monaco for...
Show moreThe Monaco treatment planning system offers three different dose calculation algorithms for use in calculating 3D treatment plans. These include Monte Carlo (MC), Collapsed Cone (CC) and the pencil beam algorithms. The aim of this study is an in-depth analysis of Monte Carlo and Collapsed Cone dose calculation methods to find the optimal parameters for clinical use for both algorithms. An end-to-end phantom with inhomogeneities was scanned and the DICOM images were imported into Monaco for contouring and planning. Treatment plans were then created in Monaco for both MC and CC using different permutations of variables for approximately 400 plans. These variables include CT Slice thickness, grid size, statistical uncertainty, and beam energy. Following planning the end-to-end phantom was then irradiated on an Elekta Linac and plans for each beam energy were created. Clinical beam data was then compared to the computed plans for each dose calculation method.
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Date Issued
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2022
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PURL
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http://purl.flvc.org/fau/fd/FA00014019
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Subject Headings
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Radiotherapy, Radiotherapy Dosage, Radiation dosimetry
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Format
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Document (PDF)
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Title
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Evaluation of surface dose outside the treatment area for breast cancer irradiation modalities using thermoluminescence dosimeters (TLDs).
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Creator
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Khanal, Suraj P., Ouhib, Zoubir, Leventouri, Theodora, Graduate College
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Date Issued
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2013-04-12
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PURL
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http://purl.flvc.org/fcla/dt/3361319
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Subject Headings
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Thermoluminescence dosimetry, Breast--Cancer--Treatment
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Format
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Document (PDF)
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Title
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COMMISSIONING AND ACCEPTANCE TESTING OF A TRUEBEAM LINEAR ACCELERATOR.
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Creator
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Dumitru, Nicolae, Pella, Silvia, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Due to the difficulty of a complex commissioning technique for a multi energetic, multi-modality linear accelerator, I perform all the commissioning and acceptance testing for a TrueBeam linear accelerator with 4 megavoltage (MV) energies of which 2 are flattening filter-free (FFF) and 6 electron energies varying from 6 MeV to 20 MeV. A 2 dimensional (2D) water tank was used for scanning all the required field sizes for all the energies. The one dimensional (1D) water tank was used to collect...
Show moreDue to the difficulty of a complex commissioning technique for a multi energetic, multi-modality linear accelerator, I perform all the commissioning and acceptance testing for a TrueBeam linear accelerator with 4 megavoltage (MV) energies of which 2 are flattening filter-free (FFF) and 6 electron energies varying from 6 MeV to 20 MeV. A 2 dimensional (2D) water tank was used for scanning all the required field sizes for all the energies. The one dimensional (1D) water tank was used to collect all the output factors for all the photon fields sizes small to medium electron field sizes. For the large electron fields sizes, we had to use the 2D water tank. All the collected data was converted into a file type accepted by the planning system (Eclipse) and subsequently imported there. Treatment plans were generated using multiple forms of planning to verify the viability and quality of the beam data commissioned.
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Date Issued
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2019
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PURL
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http://purl.flvc.org/fau/fd/FA00013301
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Subject Headings
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Linear accelerators, Cancer--Treatment, Radiation dosimetry
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Format
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Document (PDF)
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Title
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Development of an Innovative Daily QA System for Pencil-Beam Scanning Proton Therapy.
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Creator
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Kassel, Maxwell, Shang, Charles, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
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Abstract/Description
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In this work, we have developed a robust daily quality assurance (QA) system for pencil-beam scanning (PBS) dosimetry. A novel phantom and multi-PTV PBS plan were used in conjunction with the Sun Nuclear Daily QA3 multichamber detector array to verify output, range, and spot position. The sensitivity to detect change in these parameters with our designed tests was determined empirically. Associated tolerance levels were established based on these sensitivities and guidelines published in...
Show moreIn this work, we have developed a robust daily quality assurance (QA) system for pencil-beam scanning (PBS) dosimetry. A novel phantom and multi-PTV PBS plan were used in conjunction with the Sun Nuclear Daily QA3 multichamber detector array to verify output, range, and spot position. The sensitivity to detect change in these parameters with our designed tests was determined empirically. Associated tolerance levels were established based on these sensitivities and guidelines published in recent American Association of Physics in Medicine (AAPM) task group reports. The output has remained within the 3% tolerance and the range was within ±1mm. Spot position has remained within ±2mm. This daily QA procedure is quick and efficient with the time required for setup and delivery at less than 10 minutes.
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Date Issued
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2020
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PURL
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http://purl.flvc.org/fau/fd/FA00013623
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Subject Headings
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Proton Therapy, Radiation dosimetry, Quality assurance
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Format
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Document (PDF)
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Title
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Dosimetric and Radiobiological Plan Evaluation Parameters for Fractionated High-Dose Rate GYN Brachytherapy.
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Creator
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Shojaei, Marjan, Pella, Silvia, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Intracavitary high-dose-rate brachytherapy (HDRBT) is a treatment option for endometrial cancer, depending on the cancer stage. Because of the steep high dose gradient of HDRBT, very small differences in the treatment plans, surrounding organ’s anatomy, or procedures during the treatment could potentially cause significant dose variation to the tumor, as well as organs at risks (OAR) nearby the treatment area, which could result in unwanted radiobiological side effects. In this retrospective...
Show moreIntracavitary high-dose-rate brachytherapy (HDRBT) is a treatment option for endometrial cancer, depending on the cancer stage. Because of the steep high dose gradient of HDRBT, very small differences in the treatment plans, surrounding organ’s anatomy, or procedures during the treatment could potentially cause significant dose variation to the tumor, as well as organs at risks (OAR) nearby the treatment area, which could result in unwanted radiobiological side effects. In this retrospective study, the radiobiological plan evaluation parameters Equivalent Uniform Dose (EUD), Normal Tissue Complication Probability (NTCP) are used as assessment tools to evaluate HDRBT plans. Furthermore, gynecological applicator position in the coordinate system, and possible dose variations to the tumor and critical organs from the initial fraction in comparison with subsequent fractions over the entire multi fractionated treatment are studied. The evaluations were performed for 118 HDR treatment plans for 30 patients by registration of the subsequent treatment plans into the initial CT-image guided plan. Dose fractionation regimens varied from 4Gy to 7Gy per fraction, 1 or 2 fractions per week, depending on the cancer stage. Our results demonstrate no significant radiobiological impacts on organs at risks (OAR). In addition, the results of the applicator positions’ study indicate that improvement of immobilization and localization devices are recommended.
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Date Issued
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2018
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PURL
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http://purl.flvc.org/fau/fd/FA00013144
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Subject Headings
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Brachytherapy, Radiobiology, Radiation dosimetry--Evaluation
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Format
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Document (PDF)
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Title
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Dosimetric and Radiobiological Comparison of the Effects of High Definition versus Normal Collimation on Treatment Plans for Stereotactic Lung Cancer Radiation Therapy.
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Creator
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Pudasaini, Mukunda Prasad, Pella, Silvia, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Stereotactic Body Radiation Therapy (SBRT) is a modern precision radiation therapy to deliver the dose in 1 to 5 fractions with high target dose conformity, and steep dose gradient towards healthy tissues. The dose delivered is influenced by the leaf width of the MLC, especially in case of SBRT. Treatment plans with high definition (HD) MLC having leaf-width 2.5 mm and normal MLC having leaf-width 5 mm, were compared to quantify dosimetric and radiobiological parameters. Dosimetric parameters...
Show moreStereotactic Body Radiation Therapy (SBRT) is a modern precision radiation therapy to deliver the dose in 1 to 5 fractions with high target dose conformity, and steep dose gradient towards healthy tissues. The dose delivered is influenced by the leaf width of the MLC, especially in case of SBRT. Treatment plans with high definition (HD) MLC having leaf-width 2.5 mm and normal MLC having leaf-width 5 mm, were compared to quantify dosimetric and radiobiological parameters. Dosimetric parameters conformity indices (CI), gradient indices (GI) and heterogeneity indices (HI) were compared. The radiobiological parameters were evaluated by normal tissue complication probability (NTCP) and tumor control probability (TCP) based on the equivalent uniform dose (EUD). The results show that there is dosimetric and radiobiological merit of the HD MLC over the normal MLC. However, the improvement is not consistent with all the plans and thus further research is required prior to conclusion.
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Date Issued
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2018
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PURL
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http://purl.flvc.org/fau/fd/FA00013148
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Subject Headings
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Radiosurgery, Lung Neoplasms, Radiation dosimetry, Radiobiology
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Format
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Document (PDF)
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Title
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Potential Efficacy of the Monte Carlo Dose Calculations of 6MV Flattening Filter-Free Photon Beam of M6™ Cyberknife® System.
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Creator
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Neupane, Taindra, Shang, Charles, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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MapCheck measurements for 50 retrospective patient’s treatment plans suggested that MapCheck could be effectively employed in routine patient specific quality assurance in M6 Cyberknife with beams delivered at different treatment angles. However, these measurements also suggested that for highly intensity modulated MLC plans, field segments of width
Show moreMapCheck measurements for 50 retrospective patient’s treatment plans suggested that MapCheck could be effectively employed in routine patient specific quality assurance in M6 Cyberknife with beams delivered at different treatment angles. However, these measurements also suggested that for highly intensity modulated MLC plans, field segments of width < 8 mm should further be analyzed with a modified (-4%) correction factor. Results of MC simulations of the M6 Cyberknife using the EGSnrc program for 2-5 millions of incident particles in BEAMnrc and 10-20 millions in DOSXYZnrc have shown dose uncertainties within 2% for open fields from 7.6 x 7.7 mm2 to 100 x 100 mm2. Energy and corresponding FWHM were optimized by comparing with water phantom measurements at 800 mm SAD resulting to E = 7 MeV and FWHM = 2.2 mm. Good agreement of dose profiles (within 2%) and outputs (within 3%) were found between the MC simulations and water phantom measurements for the open fields.
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Date Issued
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2018
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PURL
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http://purl.flvc.org/fau/fd/FA00013147
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Subject Headings
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Radiosurgery--Quality control, Monte Carlo method, Radiation dosimetry
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Format
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Document (PDF)
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Title
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Efficacy of the virtual cone method using fixed small multi-leaf collimator field for stereotactic radiosurgery.
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Creator
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Neupane, Taindra, Leventouri, Theodora, Shang, Charles, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
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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.
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Date Issued
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2022
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PURL
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http://purl.flvc.org/fau/fd/FA00013958
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Subject Headings
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Radiation dosimetry, Radiosurgery, Collimators (Optical instrument), Monte Carlo method
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Format
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Document (PDF)
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Title
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Evaluation of surface dose outside the treatment area for breast cancer irradiation modalities using thermoluminescence dosimeters (TLDs).
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Creator
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Khanal, Suraj P., Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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The purpose of this research is to compare the surface dose outside the treatment area for different breast cancer irradiation modalities using Thermoluminescence Dosimeters (TLDs). Five different modalities are included in this study: Accuboost, Photon boost, Electron boost, Strut-Adjusted Volume Implant (SAVI), and Mammosite Multi-lumen (ML).Six points of interest (POI) on the breast cancer patients had been selected for the TLDs placement. Data from 25 breast cancer patients at Lynn Cancer...
Show moreThe purpose of this research is to compare the surface dose outside the treatment area for different breast cancer irradiation modalities using Thermoluminescence Dosimeters (TLDs). Five different modalities are included in this study: Accuboost, Photon boost, Electron boost, Strut-Adjusted Volume Implant (SAVI), and Mammosite Multi-lumen (ML).Six points of interest (POI) on the breast cancer patients had been selected for the TLDs placement. Data from 25 breast cancer patients at Lynn Cancer Institute of the Boca Raton Regional Hospital were included in the study. The measured percentage ranges of the averaged doses at the six POIs for the different modalities are: Sternum 0.26% - 3.26%, Shoulder 0.33% - 2.79%, Eye 0.26% - 1.32%, Thyroid 0.20% - 2.75%, CLB 0.2% - 5.46%, Lower Abdomen 0.16% - 2.25%.
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Date Issued
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2013
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PURL
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http://purl.flvc.org/fcla/dt/3362479
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Subject Headings
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Thermoluminescence, Therapeutic use, Radiation dosimetry, Breast, Cancer, Treatmernt, Radiation, Measurement, Methodology
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Format
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Document (PDF)
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Title
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Dosimetric Consequences of the Parotid Glands Using CT-To-CBCT Deformable Registration During IMRT For Late Stage Head And Neck Cancers.
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Creator
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Conill, Annette L., Selvaraj, Raj, Kalantzis, Georgios, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Patients receiving Intensity Modulated Radiation Therapy (IMRT) for late stage head and neck (HN) cancer often experience anatomical changes due to weight loss, tumor regression, and positional changes of normal anatomy (1). As a result, the actual dose delivered may vary from the original treatment plan. The purpose of this study was (a) to evaluate the dosimetric consequences of the parotid glands during the course of treatment, and (b) to determine if there would be an optimal timeframe...
Show morePatients receiving Intensity Modulated Radiation Therapy (IMRT) for late stage head and neck (HN) cancer often experience anatomical changes due to weight loss, tumor regression, and positional changes of normal anatomy (1). As a result, the actual dose delivered may vary from the original treatment plan. The purpose of this study was (a) to evaluate the dosimetric consequences of the parotid glands during the course of treatment, and (b) to determine if there would be an optimal timeframe for replanning. Nineteen locally advanced HN cancer patients underwent definitive IMRT. Each patient received an initial computerized tomography simulation (CT-SIM) scan and weekly cone beam computerized tomography (CBCT) scans. A Deformable Image Registration (DIR) was performed between the CT-SIM and CBCT of the parotid glands and Planning Target Volumes (PTVs) using the Eclipse treatment planning system (TPS) and the Velocity deformation software. A recalculation of the dose was performed on the weekly CBCTs using the original monitor units. The parameters for evaluation of our method were: the changes in volume of the PTVs and parotid glands, the dose coverage of the PTVs, the lateral displacement in the Center of Mass (COM), the mean dose, and Normal Tissue Complication Probability (NTCP) of the parotid glands. The studies showed a reduction of the volume in the PTVs and parotids, a medial displacement in COM, and alterations of the mean dose to the parotid glands as compared to the initial plans. Differences were observed for the dose volume coverage of the PTVs and NTCP of the parotid gland values between the initial plan and our proposed method utilizing deformable registration-based dose calculations.
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Date Issued
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2015
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PURL
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http://purl.flvc.org/fau/fd/FA00004491
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Subject Headings
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Cancer -- Radiation therapy, Head -- Cancer -- Treatment, Medical physics, Neck -- Cancer -- Treatment, Radiation dosimetry
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Format
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Document (PDF)
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Title
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Dosimetry comparison between treatment plans computed with Finite size pencil beam algorithm and Monte Carlo algorithm using InCise™ Multileaf collimator equipped CyberKnife® System.
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Creator
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Galpayage Dona, Kalpani Nisansala Udeni, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Since the release of the Cyberknife Multileaf Collimator (CK-MLC), it has been a constant concern on the realistic dose differences computed with its early-available Finite Size Pencil Beam algorithm (FSPB) from those computed by using industry well-accepted algorithms such as the Monte Carlo (MC) dose algorithm. In this study dose disparities between FSPB and MC dose calculation algorithms for selected CK-MLC treatment plans were quantified. The dosimetry for planning target volume (PTV) and...
Show moreSince the release of the Cyberknife Multileaf Collimator (CK-MLC), it has been a constant concern on the realistic dose differences computed with its early-available Finite Size Pencil Beam algorithm (FSPB) from those computed by using industry well-accepted algorithms such as the Monte Carlo (MC) dose algorithm. In this study dose disparities between FSPB and MC dose calculation algorithms for selected CK-MLC treatment plans were quantified. The dosimetry for planning target volume (PTV) and major organs at risks (OAR) was compared by calculating normalized percentage deviations (Ndev) between the two algorithms. It is found that the FSPB algorithm overestimates D95 of PTV when compared with the MC algorithm by averaging 24.0% in detached lung cases, and 15.0% in non-detached lung cases which is attributed to the absence of heterogeneity correction in the FSPB algorithm. Average dose differences are 0.3% in intracranial and 0.9% in pancreas cases. Ndev for the D95 of PTV range from 8.8% to 14.1% for the CK-MLC lung treatment plans with small field (SF ≤ 2x2cm2). Ndev is ranged from 0.5-7.0% for OARs.
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Date Issued
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2018
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PURL
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http://purl.flvc.org/fau/fd/FA00013123
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Subject Headings
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Radiosurgery, Radiation dosimetry, Monte Carlo method, Algorithms, Lung Neoplasms--radiotherapy
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Format
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Document (PDF)
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Title
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Dose Validation for Partial Accelerated Breast Irradiation treated with the SAVI Applicator.
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Creator
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Pinder, Janeil K., Pella, Silvia, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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The purpose of this study is to verify and validate the dose at various points of interest in accelerated partial breast irradiation (APBI) treated with the Strut Adjusted Volume Implant (SAVI) applicator using Thermoluminescent Dosimeters (TLDs). A set of CT images were selected from a patient’s data who had received APBI using the SAVI applicator. The images were used to make 3D models. TLDs were calibrated for Brachytherapy. Various points of interest were marked out and slots were carved...
Show moreThe purpose of this study is to verify and validate the dose at various points of interest in accelerated partial breast irradiation (APBI) treated with the Strut Adjusted Volume Implant (SAVI) applicator using Thermoluminescent Dosimeters (TLDs). A set of CT images were selected from a patient’s data who had received APBI using the SAVI applicator. The images were used to make 3D models. TLDs were calibrated for Brachytherapy. Various points of interest were marked out and slots were carved in the 3D models to fit the TLDs. CT scans were taken of the 3D models with expanded SAVI applicator inserted. A plan was made following B-39 protocol. The TLDs were read and the absorbed doses were calculated and compared to the delivered doses. The results of this study show that the overall average reading of the TLDs is within expected value. The TPS shows overestimated dose calculations for brachytherapy.
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Date Issued
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2017
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PURL
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http://purl.flvc.org/fau/fd/FA00005942
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Subject Headings
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Dissertations, Academic -- Florida Atlantic University, Thermoluminescence dosimetry., Brachytherapy., Radiotherapy Dosage., Breast--Cancer--Radiotherapy.
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Format
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Document (PDF)
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Title
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A Dosimetric Comparison of 3D-CRT, IMRT, and SAVI HDR via NTCP/TCP and DVH Analysis of Critical Organs for Breast Cancer.
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Creator
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Wisnoskie, Sarah, Pella, Silvia, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Accelerated Partial Breast Irradiation (APBI) is a common treatment of breast cancer with many modalities including 3D Conformal Radiation Therapy (3D-CRT), Intensity Modulated Radiation Therapy (IMRT), and High Dose Rate Brachytherapy (HDR). In this research, a retrospective analysis of patient’s data was performed to analyze the NTCP/TCP (Normal Tissue Complication Probability/Tumor Control Probability) and Dose Volume Histogram (DVH) parameters for HDR with SAVI, 3D, and IMRT and compare...
Show moreAccelerated Partial Breast Irradiation (APBI) is a common treatment of breast cancer with many modalities including 3D Conformal Radiation Therapy (3D-CRT), Intensity Modulated Radiation Therapy (IMRT), and High Dose Rate Brachytherapy (HDR). In this research, a retrospective analysis of patient’s data was performed to analyze the NTCP/TCP (Normal Tissue Complication Probability/Tumor Control Probability) and Dose Volume Histogram (DVH) parameters for HDR with SAVI, 3D, and IMRT and compare them focusing on critical organs such as the heart, ipsilateral lung, chest wall, ribs, and skin. TCP was 90.275%, 55.948%, and 53.369% for HDR, 3D, and IMRT respectively. The ribs were the most sensitive critical organ for all 3 modalities with a mean NTCP of 8%, 15%, and 8% for HDR, 3D, and IMRT respectively. DVH analysis showed HDR spares critical organs more than EBRT except for 2 patients receiving high doses to the ribs and chest wall.
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Date Issued
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2019
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PURL
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http://purl.flvc.org/fau/fd/FA00013281
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Subject Headings
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Radiation dosimetry--Evaluation, Breast--Cancer--Treatment, Organs, Tissues--Effect of radiation on
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Format
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Document (PDF)
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Title
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CONSISTENCY OF CT NUMBER AND ELECTRON DENSITY IN TREATMENT PLANNING SYSTEM VERSUS CT SCANNER, AND DOSIMETRIC CONSEQUENCES.
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Creator
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Hana, Evan Makdasy, Pella, Silvia, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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The Computer Tomography (CT) scanned images are very important for the Treatment Planning System (TPS) to provide the electron density of the different types of tissues that the radiation penetrates in the path to the tumor to be treated. This electron density is converted to an attenuation coefficient, which varies with tissue for each structure and even varies by the tissue volume. The purpose of this research is to evaluate the CT numbers, and convert them into relative electron densities....
Show moreThe Computer Tomography (CT) scanned images are very important for the Treatment Planning System (TPS) to provide the electron density of the different types of tissues that the radiation penetrates in the path to the tumor to be treated. This electron density is converted to an attenuation coefficient, which varies with tissue for each structure and even varies by the tissue volume. The purpose of this research is to evaluate the CT numbers, and convert them into relative electron densities. Twenty-five patients’ data and CT numbers were evaluated in the CT scanner and in Eclipse and were converted into relative electron density and compared with each other. The differences between the relative electron density in the Eclipse was found to be from 0 up to 6% between tissue equivalent materials, the final result for all equivalent tissue materials was about 2%. For the patients’ data, the percentage difference of CT number versus electron density was found to be high for high relative electron density organs, namely the final average result for the spine was 8%, less for pelvis, and less for rib while for the other organs it was even less. The very lowest was 0.3% compared with 1% which is acceptable for clinical standards.
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Date Issued
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2019
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PURL
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http://purl.flvc.org/fau/fd/FA00013315
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Subject Headings
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Tomography, X-Ray Computed, Electron density, Radiation dosimetry--Evaluation, Tomography Scanners, X-Ray Computed
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Format
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Document (PDF)
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Title
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Dosimetric and Radiobiological Comparison of Forward Tangent Intensity Modulated Radiation Therapy (FT-IMRT) and Volumetric Modulated Arc Therapy (VMAT) for Early Stage Whole Breast Cancer.
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Creator
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Moshiri Sedeh, Nader, Pella, Silvia, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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Intensity Modulated Radiation Therapy (IMRT) is a well-known type of external beam radiation therapy. The advancement in technology has had an inevitable influence in radiation oncology as well that has led to a newer and faster dose delivery technique called Volumetric Modulated Arc Therapy (VMAT). Since the presence of the VMAT modality in clinics in the late 2000, there have been many studies in order to compare the results of the VMAT modality with the current popular modality IMRT for...
Show moreIntensity Modulated Radiation Therapy (IMRT) is a well-known type of external beam radiation therapy. The advancement in technology has had an inevitable influence in radiation oncology as well that has led to a newer and faster dose delivery technique called Volumetric Modulated Arc Therapy (VMAT). Since the presence of the VMAT modality in clinics in the late 2000, there have been many studies in order to compare the results of the VMAT modality with the current popular modality IMRT for various tumor sites in the body such as brain, prostate, head and neck, cervix and anal carcinoma. This is the first study to compare VMAT with IMRT for breast cancer. The results show that the RapidArc technique in Eclipse version 11 does not improve all aspects of the treatment plans for the breast cases automatically and easily, but it needs to be manipulated by extra techniques to create acceptable plans thus further research is needed.
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Date Issued
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2015
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PURL
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http://purl.flvc.org/fau/fd/FA00004526, http://purl.flvc.org/fau/fd/FA00004526
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Subject Headings
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Breast -- Cancer -- Treatment, Cancer -- Radiation therapy, Image guided radiation therapy, Radiation dosimetry, Radiotherapy -- Technological innovations
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Format
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Document (PDF)
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Title
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Validation of a Monte Carlo dose calculation algorithm for clinical electron beams in the presence of phantoms with complex heterogeneities.
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Creator
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Enright, Shayla Landfair, Pella, Silvia, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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The purpose of this thesis is to validate the Monte Carlo algorithm for electron radiotherapy in the Eclipse™ treatment planning system (TPS), and to compare the accuracy of the Electron Monte Carlo algorithm (eMC) to the Pencil Beam algorithm (PB) in Eclipse™. Dose distributions from GafChromic™ EBT3 film measurements were compared to dose distributions from eMC and PB treatment plans. Measurements were obtained with 6MeV, 9MeV, and 12MeV electron beams at various depths. A 1 cm thick solid...
Show moreThe purpose of this thesis is to validate the Monte Carlo algorithm for electron radiotherapy in the Eclipse™ treatment planning system (TPS), and to compare the accuracy of the Electron Monte Carlo algorithm (eMC) to the Pencil Beam algorithm (PB) in Eclipse™. Dose distributions from GafChromic™ EBT3 film measurements were compared to dose distributions from eMC and PB treatment plans. Measurements were obtained with 6MeV, 9MeV, and 12MeV electron beams at various depths. A 1 cm thick solid water template with holes for bone-like and lung-like plugs was used to create assorted configurations and heterogeneities. Dose distributions from eMC plans agreed better with the film measurements based on gamma analysis. Gamma values for eMC were between 83%-99%, whereas gamma values for PB treatment plans were as low as 38.66%. Our results show that using the eMC algorithm will improve dose accuracy in regions with heterogeneities and should be considered over PB.
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Date Issued
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2014
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PURL
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http://purl.flvc.org/fau/fd/FA00004192
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Subject Headings
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Electron beams -- Therapeutic use, Image guided radiotherapy, Monte Carlo method, Proton beams -- Therapeutic use, Radiation dosimetry, Radiotherapy, High energy
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Format
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Document (PDF)