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Title: Exploring Appropriate Offset Values for Pencil Beam and Monte Carlo Dose Optimization in Lung Stereotactic Body Radiotherapy Encompassing the Effects of Respiration and Tumor Location.
Creator: Evans, Grant, Shang, Charles, Leventouri, Theodora, Graduate College
Abstract/Description: Purpose: To explore offset values in dose optimization with pencil beam (PB) algorithm to minimize dosimetric differences with plans calculated with Monte Carlo (MC) for lung cancer treatment with Stereotactic Body Radiotherapy (SBRT). Methods: 20 cases of Non-Small Cell Lung Cancer, treated with gated full motion range SBRT were selected. According to the proximity of the Gross Tumor Volume (GTV) to the chest wall, two groups are defined. Treatment plans were created on 4D average intensity...
Show morePurpose: To explore offset values in dose optimization with pencil beam (PB) algorithm to minimize dosimetric differences with plans calculated with Monte Carlo (MC) for lung cancer treatment with Stereotactic Body Radiotherapy (SBRT). Methods: 20 cases of Non-Small Cell Lung Cancer, treated with gated full motion range SBRT were selected. According to the proximity of the Gross Tumor Volume (GTV) to the chest wall, two groups are defined. Treatment plans were created on 4D average intensity projection (AIP) CT set with Brainlab iPlanDose® 4.1.2 planning system. The D97 of PTV was normalized to 50Gy using the fast PB and compared with MC. The optimized plan was then recomputed over each 4D respiratory phase, and compared with MC. Results: The mean difference in the PB and MC D97 of the ITV was 10.5% (±0.8%) of the prescription dose (50Gy). PB algorithm showed 2.3-2.4% less overestimation to the D97 of the ITV, when comparing to MC, in the maximum exhalation phase than in the maximal inhalation phase. Significantly smaller dose difference between PB and MC is also shown in plans for peripheral lesions (7.7 ± 0.7%) versus for central lesions (12.7±0.8%) (p< 0.01). Conclusions: The dosimetric differences between PB and MC can be reasonably predicted depending on the location of lesion in the lung, and may be used as offset value in dose optimization with PB. Caution is suggested when using the maximum inhalation phase for treatment planning.
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00005813
Format: Document (PDF)

Title: Exploring appropriate offset values for pencil beam and Monte Carlo dose optimization in lung stereotactic body radiotherapy encompassing the effects of respiration and tumor location.
Creator: Evans, Grant, Shang, Charles, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: Evaluation of dose optimization using the Pencil Beam (PB) and Monte Carlo (MC) algorithms may allow physicists to apply dosimetric offsets to account for inaccuracies of the PB algorithm for lung cancer treatment with Stereotactic Body Radiotherapy (SBRT). 20 cases of Non-Small Cell Lung Cancer (NSCLC) were selected. Treatment plans were created with Brainlab iPlanDose® 4.1.2. The D97 of the Planning Target Volume (PTV) was normalized to 50 Gy on the Average Intensity Projection (AIP) using...
Show moreEvaluation of dose optimization using the Pencil Beam (PB) and Monte Carlo (MC) algorithms may allow physicists to apply dosimetric offsets to account for inaccuracies of the PB algorithm for lung cancer treatment with Stereotactic Body Radiotherapy (SBRT). 20 cases of Non-Small Cell Lung Cancer (NSCLC) were selected. Treatment plans were created with Brainlab iPlanDose® 4.1.2. The D97 of the Planning Target Volume (PTV) was normalized to 50 Gy on the Average Intensity Projection (AIP) using the fast PB and compared with MC. This exact plan with the same beam Monitor Units (MUs) was recalculated over each respiratory phase. The results show that the PB algorithm has a 2.3-2.4% less overestimation at the maximum exhalation phase than the maximum inhalation phase when compared to MC. Significantly smaller dose difference between PB and MC is also shown in plans for peripheral lesions (7.7 ± 0.7%) versus central lesions (12.7±0.8%)(p< 0.01).
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004105, http://purl.flvc.org/fau/fd/FA00004105
Subject Headings: Drug development -- Computer simulation, Image guided radiation therapy, Lung cancer -- Treatment, Monte Carlo method, Proton beams, Transport theory
Format: Document (PDF)

Title: A novel method to evaluate local control of lung cancer in stereotactic body radiation therapy (SBRT) treatment using 18f-Fdg positron emission tomography (PET).
Creator: Kathriarachchi, Vindu, Shang, Charles, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: An improved method is introduced for prediction of local tumor control following lung stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). A normalized background-corrected tumor maximum Standard Uptake Value (SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of the maximum uptake of lung tumor (SUVmax). This method minimizes the variations...
Show moreAn improved method is introduced for prediction of local tumor control following lung stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). A normalized background-corrected tumor maximum Standard Uptake Value (SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of the maximum uptake of lung tumor (SUVmax). This method minimizes the variations associated with SUVmax and objectively demonstrates a strong correlation between the low SUVcmax (< 2.5-3.0) and local control of post lung SBRT. The false positive rates of both SUVmax and SUVcmax increase with inclusion of early (<6 months) PET scans, therefore such inclusion is not recommended for assessing local tumor control of post lung SBRT.
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Date Issued: 2013
PURL: http://purl.flvc.org/fau/fd/FA0004029
Subject Headings: Cancer -- Radiotherapy, Image guided radiation therapy, Lung cancer -- Treatment, Radiopharmaceuticals, Tomography, Emission
Format: Document (PDF)

Title: A Computational Study on different penalty approaches for constrained optimization in radiation therapy treatment planning with a simulated annealing algorithm.
Creator: Mohammadi Khoroushadi, Mohammad Sadegh, Shang, Charles, Ouhib, Zoubir, Graduate College, Leventouri, Theodora, Kalantzis, Georgios
Abstract/Description: Simulated Annealing algorithm is utilized for Intensity Modulated Radiation Therapy IMRT optimization. The goal in IMRT is to give the prescribed radiation dose to the tumor while minimizing the dose given to normal organs.
Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00005891
Format: Document (PDF)

Title: Dosimetric and radiobiological comparison of CyberKnife M6(TM) InCise multileaf collimator over IRIS(TM) variable collimator in prostate stereotactic body radiation therapy.
Creator: Kathriarachchi, Vindu, Shang, Charles, Evans, Grant, Leventouri, Theodora, Kalantzis, Georgios
Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FAUIR000166
Format: Citation

Title: Development of an Arduino-based 3D printed 6DOF robotic phantom and a MATLAB-based software for Radiation Therapy Quality Assurance.
Creator: Rahman, Md Mushfiqur, Leventouri, Theodora, Shang, Charles, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: Quality Assurance (QA) for medical linear accelerators (linac) is the primary concern in external beam radiation therapy. In this research, we have developed a MATLAB-based software named Quality Assurance for Linacs (QALMA), which is unique, due to cost-effectiveness, user friendly interface, and customizability. It includes five modules to perform different QA tests: Star Shot analysis, Picket Fence test, Winston-Lutz test, MLC log file analysis, and verification of light & radiation field...
Show moreQuality Assurance (QA) for medical linear accelerators (linac) is the primary concern in external beam radiation therapy. In this research, we have developed a MATLAB-based software named Quality Assurance for Linacs (QALMA), which is unique, due to cost-effectiveness, user friendly interface, and customizability. It includes five modules to perform different QA tests: Star Shot analysis, Picket Fence test, Winston-Lutz test, MLC log file analysis, and verification of light & radiation field coincidence. We also pay attention to quality assurance of 6DOF treatment couch that plays a very important role in radiation therapy. We developed an Arduino based 3D printed 6DOF robotic phantom to check the accuracy of the treatment couch. This robotic phantom was experimentally validated under clinical standards, and customizable upon requirements of the quality assurance Task. The current features of this robotic phantom open development opportunities beyond the specific couch application, such as organs motion simulation.
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Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013165
Subject Headings: Radiation therapy, Radiotherapy--Quality control, Arduino (Computer language), MATLAB
Format: Document (PDF)

Title: Development of an Innovative Daily QA System for Pencil-Beam Scanning Proton Therapy.
Creator: Kassel, Maxwell, Shang, Charles, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: 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: 2020
PURL: http://purl.flvc.org/fau/fd/FA00013623
Subject Headings: Proton Therapy, Radiation dosimetry, Quality assurance
Format: Document (PDF)

Title: Development of a Monte Carlo Simulation Model for Varian ProBeam Compact Single-Room Proton Therapy System using GEANT4.
Creator: String, Shawn, Muhammad, Wazir, Shang, Charles, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Proton therapy with pencil beam scanning technique is a novel technique to treat cancer patients due to its unique biophysical properties. However, a small error in dose calculation may lead towards undesired greater uncertainties in planed doses. This project aims to create a simulation model of Varian ProBeam Compact using the GEANT4 Monte Carlo simulation tool kit. Experimental data from the first clinical ProBeam Compact system at South Florida Proton Therapy Institute was used to...
Show moreProton therapy with pencil beam scanning technique is a novel technique to treat cancer patients due to its unique biophysical properties. However, a small error in dose calculation may lead towards undesired greater uncertainties in planed doses. This project aims to create a simulation model of Varian ProBeam Compact using the GEANT4 Monte Carlo simulation tool kit. Experimental data from the first clinical ProBeam Compact system at South Florida Proton Therapy Institute was used to validate the simulation model. A comparison was made between the experimental and simulated Integrated Depth-Dose curves using a 2%/2mm gamma index test with 100% of points passing. The beam spot standard deviation sizes (s!) were compared using percent deviation. All simulated s! matched the experimental s! within 2.5%, except 70 and 80 MeV. The model can be used to develop a more comprehensive model as an independent dose verification tool and further investigate dose distribution.
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Date Issued: 2020
PURL: http://purl.flvc.org/fau/fd/FA00013547
Subject Headings: Proton Therapy, Monte-Carlo-Simulation, Radiotherapy Dosage
Format: Document (PDF)

Title: Improved Methodology of Static HDMLC Virtual Cone based Rapid Arcs for Stereotactic Ablative Radiotherapy.
Creator: Stevens, Ryan, Shang, Charles, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: 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: 2020
PURL: http://purl.flvc.org/fau/fd/FA00013630
Subject Headings: Radiotherapy, Radiation dosimetry, Stereotaxic Techniques
Format: Document (PDF)

Title: Potential Efficacy of the Monte Carlo Dose Calculations of 6MV Flattening Filter-Free Photon Beam of M6™ Cyberknife® System.
Creator: Neupane, Taindra, Shang, Charles, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: 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: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013147
Subject Headings: Radiosurgery--Quality control, Monte Carlo method, Radiation dosimetry
Format: Document (PDF)

Title: Variations of Pericardial Dose at Different Respiratory Status in Accelerated Partial Breast Irradiation (APBI) Using Cyberknife M6™ Multileaf Collimators (CKMLC).
Creator: Long, Samanthia C., Shang, Charles, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: The purpose of this study is to investigate the changes of the pericardial dose at different respiratory phases and statuses in accelerated partial breast irradiation (APBI) using Cyberknife M6™ multileaf collimators (CK-MLC). Anonymous 6 female patient files with respiration gated four-dimensional computed tomography (4DCT) sets, and 6 left breast cancer cases with CT images in free-breathing (FB) and deep inhalation breath-hold (BH) were selected. One CT image set from each patient was...
Show moreThe purpose of this study is to investigate the changes of the pericardial dose at different respiratory phases and statuses in accelerated partial breast irradiation (APBI) using Cyberknife M6™ multileaf collimators (CK-MLC). Anonymous 6 female patient files with respiration gated four-dimensional computed tomography (4DCT) sets, and 6 left breast cancer cases with CT images in free-breathing (FB) and deep inhalation breath-hold (BH) were selected. One CT image set from each patient was planned for APBI in Accuray Multiplan™ 5.2, and respectively compared its pericardial dose with those from CT sets of other respiratory phases. All the comparable CT images were fused in the planning system according to the left chest wall, among which the lung gap anterior to the pericardium varies by the lung expansion. For the purpose of this study, the tumor volume was outlined in the media-lower quadrant of the left breast where this lung gap is relatively small. All the plans in this study met the requirements set by the National Surgical Adjuvant Breast and Bowel Project/Radiation Therapy Oncology Group (NSABP/RTOG), specifically protocol B-39/RTOG 0413. From the comparisons in this investigation, the mean relative pericardial dose of the BH CT group showed significant or 45% (p < 0.01) lower value than that of FB CT group. However, in FB 4DCT group, 3 of 6 cases indicated a meaningful reduction (p < 0.05) in 100% inhalation phase when compared with the mean dose over other phases. The inconsistent pericardial doses were displayed in FB 4DCT group due to minimal changes in the anterior lung gap of the pericardium, when the diaphragmatic breathing was dominant in those patients.
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Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004518, http://purl.flvc.org/fau/fd/FA00004518
Subject Headings: Breast--Cancer--Radiotherapy., Breast--Cancer--Treatment., Radiation--Measurement--Methodology., Medical physics.
Format: Document (PDF)

Title: Investigation of Rotational Deviations on Single Fiducial Tumor Tracking with Simulated Respiratory Motion using Synchrony® Respiratory Motion Tracking for Cyberknife® Treatment.
Creator: Christ, Zachary A., Shang, Charles, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: It is hypothesized that the uncertainty of the Synchrony® model from the rotation of a geometrically asymmetrical single fiducial shall be non-zero during the motion tracking. To validate this hypothesis, the uncertainty was measured for a Synchrony® model built for a respiratory motion phantom oriented at different yaw angles on a Cyberknife® treatment table. A Mini-ball Cube with three cylindrical GoldMark™ (1mmx5mm Au) numbered fiducials was placed inside a respiratory phantom and used for...
Show moreIt is hypothesized that the uncertainty of the Synchrony® model from the rotation of a geometrically asymmetrical single fiducial shall be non-zero during the motion tracking. To validate this hypothesis, the uncertainty was measured for a Synchrony® model built for a respiratory motion phantom oriented at different yaw angles on a Cyberknife® treatment table. A Mini-ball Cube with three cylindrical GoldMark™ (1mmx5mm Au) numbered fiducials was placed inside a respiratory phantom and used for all tests. The fiducial with the least artifact interference was selected for the motion tracking. A 2cm periodic, longitudinal, linear motion of the Mini-ball cube was executed and tested for yaw rotational angles, 0° – 90°. The test was repeated over 3 nonconsecutive days. The uncertainty increased with the yaw angle with the most noticeable changes seen between20° and 60° yaw, where uncertainty increased from 23.5% to 57.9%. A similar test was performed using a spherical Gold Anchor™ fiducial. The uncertainties found when using the Gold Anchor™ were statistically lower than those found when using the GoldMark™ fiducial for all angles of rotation. For the first time, it is found that Synchrony® model uncertainty depends on fiducial geometry. In addition, this research has shown that tracking target rotation using a single fiducial can be accomplished with the Synchrony® model uncertainty as it is displayed on the treatment console. The results of this research could lead to decreased acute toxicity effects related to multiple fiducials.
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Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013041
Subject Headings: Fiducial Markers, Radiosurgery--Quality control, Robotic radiosurgery
Format: Document (PDF)

Title: Optimization of Computed Tomography Calibration Curve for Proton Therapy Treatment Planning.
Creator: Ghasemi Ghonchehnazi, Maryam, Shang, Charles, Leventouri, Theodora, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: The accuracy of proton dose computation in the treatment planning system relies on the conversion from the Hounsfield units (HU) of each voxel in the patient CT scan to the proton stopping power ratio (SPR). The aim of this study is to investigate the potential improvement in determining proton SPR using single energy computed tomography (SECT) to reduce the uncertainty in predicting the proton range in patients. Factors which may cause CT number variations in the calibration curve have been...
Show moreThe accuracy of proton dose computation in the treatment planning system relies on the conversion from the Hounsfield units (HU) of each voxel in the patient CT scan to the proton stopping power ratio (SPR). The aim of this study is to investigate the potential improvement in determining proton SPR using single energy computed tomography (SECT) to reduce the uncertainty in predicting the proton range in patients. Factors which may cause CT number variations in the calibration curve have been examined. The HU-SPR calibration curve was determined based on HU of human body tissues using the stoichiometric method. The uncertainties in SPR were divided into two major categories: The inherent uncertainty, and the CT number uncertainty. The root mean square errors of the inherent uncertainties were estimated 0.02%, 0.61% and 0.26% for lung tissues, soft tissues (excluding Thyroid), and bone tissues, respectively. The total uncertainties due to the inherent uncertainty and CT imaging errors were estimated 1.50%. The average calibration curve of two sized phantoms (head and body) were used in the treatment planning system to mitigate beam hardening effect through the attenuating media. A higher accuracy of the SPR prediction using the stoichiometric method is suggested through comparison with the predicted SPRs that derived from the direct calibration approach.
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Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013374
Subject Headings: Proton Therapy, Tomography, Calibration, Tomography, X-Ray Computed
Format: Document (PDF)

Title: Nuclear Halo Effect and Field Size Factor for Pencil-Beam Scanning Proton Therapy.
Creator: Beqiri, Atdhe, Shang, Charles, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: In proton therapy systems with pencil-beam scanning, output of Halo effect is not necessarily included in Treatment Planning System (TPS). Halo effect (low-intensity tail) can significantly affect a patient’s dose distribution. The output of this dose depends on the field size being irradiated. Although much research has been made to investigate such relation to the field size, the number of reports on dose calculations including the halo effect is small. In this work we have investigated the...
Show moreIn proton therapy systems with pencil-beam scanning, output of Halo effect is not necessarily included in Treatment Planning System (TPS). Halo effect (low-intensity tail) can significantly affect a patient’s dose distribution. The output of this dose depends on the field size being irradiated. Although much research has been made to investigate such relation to the field size, the number of reports on dose calculations including the halo effect is small. In this work we have investigated the Halo effect, including field size factor, target depth factor, and air gaps with a range shifter for a Varian ProBeam. Dose calculations created on the Eclipse Treatment Planning System (vs15.6 TPS) are compared with plane-parallel ionization chambers (PTW Octavius 1500) measurements using PCS and AcurosPT MC model in different isocenters: 5cm, 10cm, and 20cm. We find that in AcurosPT algorithm deviations range between -7.53% (for 2cm field in 25cm air gap with range shifter) up to +7.40% (for 20cm field in 15cm air gap with range shifter). Whereas, in PCS algorithm the deviations are -2.07% (for 20x20cm field in open conditions) to -6.29% (for 20x20cm field in 25cm air gap with range shifter).
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Date Issued: 2021
PURL: http://purl.flvc.org/fau/fd/FA00013788
Subject Headings: Proton Therapy, Proton beams, Radiotherapy
Format: Document (PDF)

Title: Commissioning of 360⁰ Rotational Single Room ProBeam Compact™ (Varian Medical) Pencil Beam Scanning Proton Therapy System.
Creator: Fathallah, Shreen Mohamed, Shang, Charles, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: 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: 2021
PURL: http://purl.flvc.org/fau/fd/FA00013691
Subject Headings: Proton Therapy, Dosimetry
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: 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: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013958
Subject Headings: Radiation dosimetry, Radiosurgery, Collimators (Optical instrument), Monte Carlo method
Format: Document (PDF)

FAU Theses and Dissertations (13)	+ -
FAU Graduate Student Research (2)	+ -
FAU College Collections (1)	+ -

Proton Therapy (5)	+ -
Radiation dosimetry (4)	+ -
Monte Carlo method (3)	+ -
Image guided radiation therapy (2)	+ -
Lung cancer -- Treatment (2)	+ -

Proton beams (2)	+ -
Radiosurgery--Quality control (2)	+ -
Radiotherapy (2)	+ -
Arduino (Computer language) (1)	+ -
Breast--Cancer--Radiotherapy. (1)	+ -
Breast--Cancer--Treatment. (1)	+ -
Calibration (1)	+ -
Cancer -- Radiotherapy (1)	+ -
Collimators (Optical instrument) (1)	+ -
Dosimetry (1)	+ -
Drug development -- Computer simulation (1)	+ -
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article (1)	+ -
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Shang, Charles (16)	+ -
Charles E. Schmidt College of Science (13)	+ -
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Florida Atlantic University (12)	+ -
Leventouri, Theodora (9)	+ -

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