bluuebunny/crossref_metadata_2025_split huggingface dataset:
TU‐G‐BRD‐08: In‐Vivo EPID Dosimetry: Quantifying the Detectability of Four Classes of Errors
Authors: Ford E , Phillips M , Bojechko C 
Published: June 2015

Purpose:EPID dosimetry is an emerging method for treatment verification and QA. Given that the in‐vivo EPID technique is in clinical use at some centers, we investigate the sensitivity and specificity for detecting different classes of errors. We assess the impact of these errors using dose volume histogram endpoints. Though data exist for EPID dosimetry performed pre‐treatment, this is the first study quantifying its effectiveness when used during patient treatment (in‐vivo).Methods:We analyzed 17 patients; EPID images of the exit dose were acquired and used to reconstruct the planar dose at isocenter. This dose was compared to the TPS dose using a 3%/3mm gamma criteria. To simulate errors, modifications were made to treatment plans using four possible classes of error: 1) patient misalignment, 2) changes in patient body habitus, 3) machine output changes and 4) MLC misalignments. Each error was applied with varying magnitudes. To assess the detectability of the error, the area under a ROC curve (AUC) was analyzed. The AUC was compared to changes in D99 of the PTV introduced by the simulated error.Results:For systematic changes in the MLC leaves, changes in the machine output and patient habitus, the AUC varied from 0.78–0.97 scaling with the magnitude of the error. The optimal gamma threshold as determined by the ROC curve varied between 84–92%. There was little diagnostic power in detecting random MLC leaf errors and patient shifts (AUC 0.52–0.74). Some errors with weak detectability had large changes in D99.Conclusion:These data demonstrate the ability of EPID‐based in‐vivo dosimetry in detecting variations in patient habitus and errors related to machine parameters such as systematic MLC misalignments and machine output changes. There was no correlation found between the detectability of the error using the gamma pass rate, ROC analysis and the impact on the dose volume histogram.Funded by grant R18HS022244 from AHRQ
TU‐G‐BRB‐01: Topic Introduction: Do We Need Clinical Trials in Particle Therapy and How Can Medical Physics Support Them?
Authors: Schulte R. 
Published: June 2015

Proton therapy, in particular, and ion therapy, just beginning, are becoming an increasing focus of attention in clinical radiation oncology and medical physics. Both modalities have been criticized of lacking convincing evidence from randomized trials proving their efficacy, justifying the higher costs involved in these therapies.This session will provide an overview of the current status of clinical trials in proton therapy, including recent developments in ion therapy. As alluded to in the introductory talk by Dr. Schulte, opinions are diverging widely as to the usefulness and need for clinical trials in particle therapy and the challenge of equipoise. The lectures will highlight some of the challenges that surround clinical trials in particle therapy. One, presented by Dr. Choy from UT Southwestern, is that new technology and even different types of particles such as helium and carbon ions are introduced into this environment, increasing the phase space of clinical variables. The other is the issue of medical physics quality assurance with physical phantoms, presented by Mrs. Taylor from IROC Houston, which is more challenging because 3D and 4D image guidance and active delivery techniques are in relatively early stages of development. The role of digital phantoms in developing clinical treatment planning protocols and as a QA tool will also be highlighted by Dr. Lee from NCI.The symposium will be rounded off by a panel discussion among the Symposium speakers, arguing pro or con the need and readiness for clinical trials in proton and ion therapy.Learning Objectives:

To get an update on the current status of clinical trials allowing or mandating proton therapy.
Learn about the status of planned clinical trials in the U.S. and worldwide involving ion therapy.
Discuss the challenges in the design and QA of clinical trials in particle therapy.
Learn about existing and future physical and computational anthropomorphic phantoms for charged particle clinical trial development and support.
Research reported in this presentation is supported by the National Cancer Institute of the National; Institutes of Health under Award Number P20CA183640.
TU‐G‐BRB‐02: Clinical Trials in Particle Therapy ‐ Open Questions
Authors: Choy H. 
Published: June 2015

Proton therapy, in particular, and ion therapy, just beginning, are becoming an increasing focus of attention in clinical radiation oncology and medical physics. Both modalities have been criticized of lacking convincing evidence from randomized trials proving their efficacy, justifying the higher costs involved in these therapies.This session will provide an overview of the current status of clinical trials in proton therapy, including recent developments in ion therapy. As alluded to in the introductory talk by Dr. Schulte, opinions are diverging widely as to the usefulness and need for clinical trials in particle therapy and the challenge of equipoise. The lectures will highlight some of the challenges that surround clinical trials in particle therapy. One, presented by Dr. Choy from UT Southwestern, is that new technology and even different types of particles such as helium and carbon ions are introduced into this environment, increasing the phase space of clinical variables. The other is the issue of medical physics quality assurance with physical phantoms, presented by Mrs. Taylor from IROC Houston, which is more challenging because 3D and 4D image guidance and active delivery techniques are in relatively early stages of development. The role of digital phantoms in developing clinical treatment planning protocols and as a QA tool will also be highlighted by Dr. Lee from NCI.The symposium will be rounded off by a panel discussion among the Symposium speakers, arguing pro or con the need and readiness for clinical trials in proton and ion therapy.Learning Objectives:

To get an update on the current status of clinical trials allowing or mandating proton therapy.
Learn about the status of planned clinical trials in the U.S. and worldwide involving ion therapy.
Discuss the challenges in the design and QA of clinical trials in particle therapy.
Learn about existing and future physical and computational anthropomorphic phantoms for charged particle clinical trial development and support.
Research reported in this presentation is supported by the National Cancer Institute of the National; Institutes of Health under Award Number P20CA183640.
TU‐G‐BRB‐03: IROC Houston's Proton Beam Validation for Clinical Trials
Authors: Taylor P. 
Published: June 2015

Proton therapy, in particular, and ion therapy, just beginning, are becoming an increasing focus of attention in clinical radiation oncology and medical physics. Both modalities have been criticized of lacking convincing evidence from randomized trials proving their efficacy, justifying the higher costs involved in these therapies.This session will provide an overview of the current status of clinical trials in proton therapy, including recent developments in ion therapy. As alluded to in the introductory talk by Dr. Schulte, opinions are diverging widely as to the usefulness and need for clinical trials in particle therapy and the challenge of equipoise. The lectures will highlight some of the challenges that surround clinical trials in particle therapy. One, presented by Dr. Choy from UT Southwestern, is that new technology and even different types of particles such as helium and carbon ions are introduced into this environment, increasing the phase space of clinical variables. The other is the issue of medical physics quality assurance with physical phantoms, presented by Mrs. Taylor from IROC Houston, which is more challenging because 3D and 4D image guidance and active delivery techniques are in relatively early stages of development. The role of digital phantoms in developing clinical treatment planning protocols and as a QA tool will also be highlighted by Dr. Lee from NCI.The symposium will be rounded off by a panel discussion among the Symposium speakers, arguing pro or con the need and readiness for clinical trials in proton and ion therapy.Learning Objectives:

To get an update on the current status of clinical trials allowing or mandating proton therapy.
Learn about the status of planned clinical trials in the U.S. and worldwide involving ion therapy.
Discuss the challenges in the design and QA of clinical trials in particle therapy.
Learn about existing and future physical and computational anthropomorphic phantoms for charged particle clinical trial development and support.
Research reported in this presentation is supported by the National Cancer Institute of the National; Institutes of Health under Award Number P20CA183640.
TU‐G‐BRB‐04: Digital Phantoms for Developing Protocols in Particle Therapy
Authors: Lee C. 
Published: June 2015

Proton therapy, in particular, and ion therapy, just beginning, are becoming an increasing focus of attention in clinical radiation oncology and medical physics. Both modalities have been criticized of lacking convincing evidence from randomized trials proving their efficacy, justifying the higher costs involved in these therapies.This session will provide an overview of the current status of clinical trials in proton therapy, including recent developments in ion therapy. As alluded to in the introductory talk by Dr. Schulte, opinions are diverging widely as to the usefulness and need for clinical trials in particle therapy and the challenge of equipoise. The lectures will highlight some of the challenges that surround clinical trials in particle therapy. One, presented by Dr. Choy from UT Southwestern, is that new technology and even different types of particles such as helium and carbon ions are introduced into this environment, increasing the phase space of clinical variables. The other is the issue of medical physics quality assurance with physical phantoms, presented by Mrs. Taylor from IROC Houston, which is more challenging because 3D and 4D image guidance and active delivery techniques are in relatively early stages of development. The role of digital phantoms in developing clinical treatment planning protocols and as a QA tool will also be highlighted by Dr. Lee from NCI.The symposium will be rounded off by a panel discussion among the Symposium speakers, arguing pro or con the need and readiness for clinical trials in proton and ion therapy.Learning Objectives:

To get an update on the current status of clinical trials allowing or mandating proton therapy.
Learn about the status of planned clinical trials in the U.S. and worldwide involving ion therapy.
Discuss the challenges in the design and QA of clinical trials in particle therapy.
Learn about existing and future physical and computational anthropomorphic phantoms for charged particle clinical trial development and support.
Research reported in this presentation is supported by the National Cancer Institute of the National; Institutes of Health under Award Number P20CA183640.
TU‐G‐BRB‐05: Panel Discussion: Clinical Trials in Proton and Ion Therapy ‐ Are We Ready?
Authors: Schulte R. 
Published: June 2015

Proton therapy, in particular, and ion therapy, just beginning, are becoming an increasing focus of attention in clinical radiation oncology and medical physics. Both modalities have been criticized of lacking convincing evidence from randomized trials proving their efficacy, justifying the higher costs involved in these therapies.This session will provide an overview of the current status of clinical trials in proton therapy, including recent developments in ion therapy. As alluded to in the introductory talk by Dr. Schulte, opinions are diverging widely as to the usefulness and need for clinical trials in particle therapy and the challenge of equipoise. The lectures will highlight some of the challenges that surround clinical trials in particle therapy. One, presented by Dr. Choy from UT Southwestern, is that new technology and even different types of particles such as helium and carbon ions are introduced into this environment, increasing the phase space of clinical variables. The other is the issue of medical physics quality assurance with physical phantoms, presented by Mrs. Taylor from IROC Houston, which is more challenging because 3D and 4D image guidance and active delivery techniques are in relatively early stages of development. The role of digital phantoms in developing clinical treatment planning protocols and as a QA tool will also be highlighted by Dr. Lee from NCI.The symposium will be rounded off by a panel discussion among the Symposium speakers, arguing pro or con the need and readiness for clinical trials in proton and ion therapy.Learning Objectives:

To get an update on the current status of clinical trials allowing or mandating proton therapy.
Learn about the status of planned clinical trials in the U.S. and worldwide involving ion therapy.
Discuss the challenges in the design and QA of clinical trials in particle therapy.
Learn about existing and future physical and computational anthropomorphic phantoms for charged particle clinical trial development and support.
Research reported in this presentation is supported by the National Cancer Institute of the National; Institutes of Health under Award Number P20CA183640.
TU‐G‐BRA‐01: Assessing Radiation‐Induced Reductions in Regional Lung Perfusion Following Stereotactic Radiotherapy for Lung Cancer
Authors: McGurk R , Schreiber E , Das S , Zagar T , Green R , Lawrence M , Sheikh A , McCartney W , Rivera P , Marks L 
Published: June 2015

Purpose:The dose‐dependent nature of radiation therapy (RT)‐induced lung injury following hypo‐fractionated stereotactic RT is unclear. We herein report preliminary results of a prospective study assessing the magnitude of RT‐induced reductions in regional lung perfusion following hypo‐fractionated stereotactic RT.Methods:Four patients undergoing hypo‐fractionated stereotactic lung RT (SBRT: 12 Gy × 4 fractions or 10 Gy × 5 fractions) had a pre‐treatment SPECT (single‐photon emission computed tomography) perfusion scan providing a 3D map of regional lung perfusion. Scans were repeated 3–6 months post‐treatment. Pre‐ and post SPECT scans were registered to the planning CT scan (and hence the 3D dose data). Changes in regional perfusion (counts per cc on the pre‐post scans) were computed in regions of the lung exposed to different doses of radiation (in 5 Gy intervals), thus defining a dose‐response function. SPECT scans were internally normalized to the regions receiving <5 Gy.Results:At 3 months post‐RT, the changes in perfusion are highly variable. At 6 months, there is a consistent dose‐dependent reduction in regional perfusion. The average percent decline in regional perfusion was 10% at 15–20 Gy, 20% at 20–25 Gy, and 30% at 25–30 Gy representing a relatively linear dose response with an approximate 2% reduction per Gray for doses in excess of 10 Gy. There was a subtle increase in perfusion in the lung receiving <10 Gy.Conclusion:Hypo‐fractionated stereotactic RT appears to cause a dose‐dependent reduction in regional lung perfusion. There appears to be a threshold effect with no apparent perfusion loss at doses <10 Gy, though this might be in part due to the normalization technique used. Additional data is needed from a larger number of patients to better assess this issue. This sort of data can be used to assist optimizing RT treatment plans that minimize the risk of lung injury.Partly supported by the NIH (CA69579) and the Lance Armstrong Foundation
TU‐G‐BRA‐02: Can We Extract Lung Function Directly From 4D‐CT Without Deformable Image Registration?
Authors: Kipritidis J , Hofman M , Siva S , Callahan J , Le Roux P , Woodruff H , Counter W , Hardcastle N , Keall P 
Published: June 2015

Purpose:Dynamic CT ventilation imaging (CT‐VI) visualizes air volume changes in the lung by evaluating breathing‐induced lung motion using deformable image registration (DIR). Dynamic CT‐VI could enable functionally adaptive lung cancer radiation therapy, but its sensitivity to DIR parameters poses challenges for validation. We hypothesize that a direct metric using CT parameters derived from Hounsfield units (HU) alone can provide similar ventilation images without DIR. We compare the accuracy of Direct and Dynamic CT‐VIs versus positron emission tomography (PET) images of inhaled ⁶⁸Ga‐labelled nanoparticles (‘Galligas’).Methods:25 patients with lung cancer underwent Galligas 4D‐PET/CT scans prior to radiation therapy. For each patient we produced three CT‐ VIs. (i) Our novel method, Direct CT‐VI, models blood‐gas exchange as the product of air and tissue density at each lung voxel based on time‐averaged 4D‐CT HU values. Dynamic CT‐VIs were produced by evaluating: (ii) regional HU changes, and (iii) regional volume changes between the exhale and inhale 4D‐CT phase images using a validated B‐spline DIR method. We assessed the accuracy of each CT‐VI by computing the voxel‐wise Spearman correlation with free‐breathing Galligas PET, and also performed a visual analysis.Results:Surprisingly, Direct CT‐VIs exhibited better global correlation with Galligas PET than either of the dynamic CT‐VIs. The (mean ± SD) correlations were (0.55 ± 0.16), (0.41 ± 0.22) and (0.29 ± 0.27) for Direct, Dynamic HU‐based and Dynamic volume‐based CT‐VIs respectively. Visual comparison of Direct CT‐VI to PET demonstrated similarity for emphysema defects and ventral‐to‐dorsal gradients, but inability to identify decreased ventilation distal to tumor‐obstruction.Conclusion:Our data supports the hypothesis that Direct CT‐VIs are as accurate as Dynamic CT‐VIs in terms of global correlation with Galligas PET. Visual analysis, however, demonstrated that different CT‐VI algorithms might have varying accuracy depending on the underlying cause of ventilation abnormality.This research was supported by a National Health and Medical Research Council (NHMRC) Australia Fellowship, an Cancer Institute New South Wales Early Career Fellowship 13‐ECF‐1/15 and NHMRC scholarship APP1038399. No commercial funding was received for this work.
TU‐G‐303‐01: Radiomics: Quantitative Imaging in the Service of Improved Treatment Decision Making
Authors: Deasy J. 
Published: June 2015

‘Radiomics’ refers to studies that extract a large amount of quantitative information from medical imaging studies as a basis for characterizing a specific aspect of patient health. Radiomics models can be built to address a wide range of outcome predictions, clinical decisions, basic cancer biology, etc. For example, radiomics models can be built to predict the aggressiveness of an imaged cancer, cancer gene expression characteristics (radiogenomics), radiation therapy treatment response, etc. Technically, radiomics brings together quantitative imaging, computer vision/image processing, and machine learning. In this symposium, speakers will discuss approaches to radiomics investigations, including: longitudinal radiomics, radiomics combined with other biomarkers (‘pan‐omics’), radiomics for various imaging modalities (CT, MRI, and PET), and the use of registered multi‐modality imaging datasets as a basis for radiomics. There are many challenges to the eventual use of radiomics‐derived methods in clinical practice, including: standardization and robustness of selected metrics, accruing the data required, building and validating the resulting models, registering longitudinal data that often involve significant patient changes, reliable automated cancer segmentation tools, etc. Despite the hurdles, results achieved so far indicate the tremendous potential of this general approach to quantifying and using data from medical images. Specific applications of radiomics to be presented in this symposium will include: the longitudinal analysis of patients with low‐grade gliomas; automatic detection and assessment of patients with metastatic bone lesions; image‐based monitoring of patients with growing lymph nodes; predicting radiotherapy outcomes using multi‐modality radiomics; and studies relating radiomics with genomics in lung cancer and glioblastoma.Learning Objectives:

Understanding the basic image features that are often used in radiomic models.
Understanding requirements for reliable radiomic models, including robustness of metrics, adequate predictive accuracy, and generalizability.
Understanding the methodology behind radiomic‐genomic (‘radiogenomics’) correlations.
Research supported by NIH (US), CIHR (Canada), and NSERC (Canada)
TU‐G‐303‐03: Machine Learning to Improve Human Learning From Longitudinal Image Sets
Authors: Veeraraghavan H. 
Published: June 2015

‘Radiomics’ refers to studies that extract a large amount of quantitative information from medical imaging studies as a basis for characterizing a specific aspect of patient health. Radiomics models can be built to address a wide range of outcome predictions, clinical decisions, basic cancer biology, etc. For example, radiomics models can be built to predict the aggressiveness of an imaged cancer, cancer gene expression characteristics (radiogenomics), radiation therapy treatment response, etc. Technically, radiomics brings together quantitative imaging, computer vision/image processing, and machine learning. In this symposium, speakers will discuss approaches to radiomics investigations, including: longitudinal radiomics, radiomics combined with other biomarkers (‘pan‐omics’), radiomics for various imaging modalities (CT, MRI, and PET), and the use of registered multi‐modality imaging datasets as a basis for radiomics. There are many challenges to the eventual use of radiomics‐derived methods in clinical practice, including: standardization and robustness of selected metrics, accruing the data required, building and validating the resulting models, registering longitudinal data that often involve significant patient changes, reliable automated cancer segmentation tools, etc. Despite the hurdles, results achieved so far indicate the tremendous potential of this general approach to quantifying and using data from medical images. Specific applications of radiomics to be presented in this symposium will include: the longitudinal analysis of patients with low‐grade gliomas; automatic detection and assessment of patients with metastatic bone lesions; image‐based monitoring of patients with growing lymph nodes; predicting radiotherapy outcomes using multi‐modality radiomics; and studies relating radiomics with genomics in lung cancer and glioblastoma.Learning Objectives:

Understanding the basic image features that are often used in radiomic models.
Understanding requirements for reliable radiomic models, including robustness of metrics, adequate predictive accuracy, and generalizability.
Understanding the methodology behind radiomic‐genomic (‘radiogenomics’) correlations.
Research supported by NIH (US), CIHR (Canada), and NSERC (Canada)