bluuebunny/crossref_metadata_2025 huggingface dataset:
TU‐AB‐BRA‐10: Treatment of Gastric MALT Lymphoma Utilizing a Magnetic Resonance Image‐Guided Radiation Therapy (MR‐IGRT) System: Evaluation of Gating Feasibility
Authors: Mazur T , Gach H , Chundury A , Fischer‐Valuck B , Huang J , Thomas M , Green O
Published: July 2016

Purpose:

To evaluate the feasibility of real‐time, real‐anatomy tracking and gating for gastric lymphoma patients treated with magnetic resonance image‐guided radiation therapy (MR‐IGRT)

Methods:

Over the last 2 years, 8 patients with gastric lymphoma were treated with 0.3‐T, Co‐60 MR‐IGRT. Post‐treatment analysis of real‐time cine imaging in the sagittal plane during each patient's treatment revealed significant motion of the stomach. While this motion was accounted for with generous PTV margins, the system's capability for real‐time, real‐anatomy tracking could be used to reduce treatment margins by gating. However, analysis was needed for the feasibility of gating using only the single available sagittal imaging plane. While any plane may be chosen, if the stomach moves differently where it is not being observed, there may potentially be a mistreatment. To that end, imaging with healthy volunteers was done to ascertain stomach motion over 2–4 min by analyzing multiple parallel sagittal and coronal planes 0.75 cm apart. The stomach was contoured on every slice, and the mean displacement between pairs of contour centroids was used to determine the amount of overall motion.

Results:

The mean displacement of the centroid in the image plane was 4.3 ± 0.7 mm. The greatest observed motion was more medial with respect to the patient, and less motion laterally, which implies that gating on a plane located closer to MRI isocenter will provide the more conservative scenario as it will turn the radiation delivery off when the stomach is observed to move outside a predetermined boundary.

Conclusion:

The stomach was observed to move relatively uniformly throughout, with maximum extent of motion closer to where most MRI systems have the best spatial integrity (near isocenter). Analysis of possible PTV margins from the healthy volunteer study (coupled with previous patient data on interfraction volumetric stomach deformation) is pending.
TU‐AB‐BRA‐12: Quality Assurance of An Integrated Magnetic Resonance Image Guided Adaptive Radiotherapy Machine Using Cherenkov Imaging
Authors: Andreozzi J , Mooney K , Bruza P , Curcuru A , Saunders S , Gladstone D , Pogue B , Green O
Published: July 2016

Purpose:

To investigate the viability of using Cherenkov imaging as a fast and robust method for quality assurance tests in the presence of a magnetic field, where other instruments can be limited.

Methods:

Water tank measurements were acquired from a clinically utilized adaptive magnetic resonance image guided radiation therapy (MR‐IGRT) machine with three multileaf‐collimator equipped 60Co sources. Cherenkov imaging used an intensified charge coupled device (ICCD) camera placed 3.5m from the treatment isocenter, looking down the bore of the 0.35T MRI into a water tank. Images were post‐processed to make quantitative comparison between Cherenkov light intensity with both film and treatment planning system predictions, in terms of percent depth dose curves as well as lateral beam profile measurements. A TG‐119 commissioning test plan (C4: C‐Shape) was imaged in real‐time at 6.33 frames per second to investigate the temporal and spatial resolution of the Cherenkov imaging technique.

Results:

A .33mm/pixel Cherenkov image resolution was achieved across 1024×1024 pixels in this setup. Analysis of the Cherenkov image of a 10.5×10.5cm treatment beam in the water tank successfully measured the beam width at the depth of maximum dose within 1.2% of the film measurement at the same point. The percent depth dose curve for the same beam was on average within 2% of ionization chamber measurements for corresponding depths between 3–100mm. Cherenkov video of the TG‐119 test plan provided qualitative agreement with the treatment planning system dose predictions, and a novel temporal verification of the treatment.

Conclusions:

Cherenkov imaging was successfully used to make QA measurements of percent depth dose curves and cross beam profiles of MRI‐IGRT radiotherapy machines after only several seconds of beam‐on time and data capture; both curves were extracted from the same data set. Video‐rate imaging of a dynamic treatment plan provided new information regarding temporal dose deposition.

This study has been funded by NIH grants R21EB17559 and R01CA109558, as well as Norris Cotton Cancer Center Pilot funding.
TU‐AB‐202‐02: Deformable Image Registration Accuracy Between External Beam Radiotherapy and HDR Brachytherapy CT Images for Cervical Cancer Using a 3D‐Printed Deformable Pelvis Phantom
Authors: Miyasaka Y , Kadoya N , Kuroda Y , Ito K , Chiba M , Nakajima Y , Sato K , Dobashi S , Takeda K , Jingu K
Published: July 2016

Purpose:

Accurate deformable image registration (DIR) between external beam radiotherapy (EBRT) and HDR brachytherapy (BT) CT images in cervical cancer is challenging. DSC has been evaluated only on the basis of the consistency of the structure, and its use does not guarantee an anatomically reasonable deformation. We evaluate the DIR accuracy for cervical cancer with DSC and anatomical landmarks using a 3D‐printed pelvis phantom.

Methods:

A 3D‐printed, deformable female pelvis phantom was created on the basis of the patient's CT image. Urethane and silicon were used as materials for creating the uterus and bladder, respectively, in the phantom. We performed DIR in two cases: case‐A with a full bladder (170 ml) in both the EBRT and BT images and case‐B with a full bladder in the BT image and a half bladder (100 ml) in the EBRT image. DIR was evaluated using DSCs and 70 uterus and bladder landmarks. A Hybrid intensity and structure DIR algorithm with two settings (RayStation) was used.

Results:

In the case‐A, DSCs of the intensity‐based DIR were 0.93 and 0.85 for the bladder and uterus, respectively, whereas those of hybrid‐DIR were 0.98 and 0.96, respectively. The mean landmark error values of intensity‐based DIR were 0.73±0.29 and 1.70±0.19 cm for the bladder and uterus, respectively, whereas those of Hybrid‐DIR were 0.43±0.33 and 1.23±0.25 cm, respectively. In both cases, the Hybrid‐DIR accuracy was better than the intensity‐based DIR accuracy for both evaluation methods. However, for several bladder landmarks, the Hybrid‐DIR landmark errors were larger than the corresponding intensity‐based DIR errors (e.g., 2.26 vs 1.25 cm).

Conclusion:

Our results demonstrate that Hybrid‐DIR can perform with a better accuracy than the intensity‐based DIR for both DSC and landmark errors; however, Hybrid‐DIR shows a larger landmark error for some landmarks because the technique focuses on both the structure and intensity.
TU‐AB‐202‐04: Development of a DeformableImage Registration (DIR) Error Correction Method Employing Kolmogorov‐Zurbenko(KZ) Filter
Authors: Liang X , Wang C , Chang Z , Yin F , Cai J
Published: July 2016

Purpose:

This study aims to develop a DIR error correction method capable of utilizing sparse ground‐truth motion information and recovering missing data with the Kolmogorov‐Zurbenko (KZ) filter.

Methods:

The error correction method employs a two‐step approach. First, sparse ground‐truth displacement vectors are integrated into a pre‐correction deformable vector field (DVF) to estimate a post‐correction DVF with coarse resolution. Second, the coarse post‐correction DVF is boosted to a full‐resolution DVF through convolution with the KZ filter. To validate the use of the KZ filter for missing data recovery, recovery errors were determined by comparing a DVF recovered from down‐sampling with the original full‐resolution DVF. The entire error correction method was tested on an in‐house developed digital lung motion phantom consisting of a primary volume, a DVF, and a secondary volume synthesized by applying the DVF on the primary volume. Five pre‐correction DVFs were obtained by performing DIR between the two volumes using Velocity, MIM, ILK and OHS algorithms in DIRART toolbox, and Elastix, and then corrected. Primary volumes were synthesized with pre‐ and post‐correction DVFs, respectively. The error correction method was evaluated with pre‐ and post‐correction registration errors, and intensity errors in synthesized primary volumes.

Results:

Our test results for sparsely down‐sampled (<0.4%) DVFs showed that the KZ filter outperformed the cubic polynomial interpolation method for whole lung DVF map recovery in terms of median error (0.60mm vs 0.73mm) and mean error (1.18mm vs 1.29mm). Pre‐ and post‐correction 3D registration errors per voxel for Velocity, MIM, ILK, OHS, and Elastix are reduced by 2.39 mm on average. Pre‐ and post‐correction intensity errors are reduced by 0.37 in unit of image intensity on average.

Conclusion:

We have implemented a two‐step method capable of utilizing sparse ground‐truth displacement vectors for DIR error reduction, allowing DIR accuracy improvement utilizing clinically available motion data.

This study is supported by NIH grant 1R21CA165384.
TU‐AB‐202‐09: Performance of Cross‐Modality DIR Algorithms Using Images Computed from a Novel, Tissue‐Like Phantom Capable of Reproducible Degrees of Deformation
Authors: Ionascu D , Castillo E , Qin A , Solis D , Lack D , Sandhu R , Yee S , Guerrero T
Published: July 2016

Purpose:

Develop a framework for the spatial accuracy assessment of multi‐modality deformable image registration (DIR) based on precise and reproducible deformations of a novel prostate phantom.

Methods:

An existing, tissue‐like prostate phantom has been adapted to allow quantifiable, reproducible, and variable degrees of volumetric deformation. This phantom is sequentially deformed into 11 stationary deformation states that can be individually imaged using CT, MRI, US and CBCT. The deformation is induced programmatically by changing the water volume of a balloon using a precise syringe pusher (5ml increments), effectively displacing and deforming the prostate and surrounding tissue. To demonstrate the phantom's utility as a DIR assessment tool, selected DIR algorithms (CT<‐>MR: Normalized Mutual Information, MR‐MR: Mutual Information, CT‐CT: Local Cross‐Correlation+Mutual Information) were applied to intra and cross‐imaging modalities depicting varying degrees of deformation. DIR accuracy was assessed via the DICE overlap score, calculated between the deformed prostate contour (computed by warping the manually delineated contour on the initial deformation state) and the manually delineated contour on the target deformation state.

Results:

DICE coefficients show excellent agreement of individual deformation states for MR and CT, hence validating the reproducibility of the induced deformation (< 1.0 + 0.1 %). Intra‐modality DIR (MR‐MR, CT‐CT) shows good performance (0.93–0.98). CT‐to‐MR performance is acceptable only for the closest 5–6 deformation states (> 0.94), while the DIR solutions for farthest 6 deformation states (0.78–0.92) are erroneous or artifactual. MR‐to‐CT DIR performance is demonstrably weaker (0.0–0.96) yielding asymmetrical errors w.r.t. the initial deformation state (no‐deformation vs. maxdeformation). Moreover, the first 3 deformed contours show zero overlap with the manual contours.

Conclusion:

We have developed a novel prostate phantom capable of gradual and reproducible deformation, and demonstrated its ability to assess multi‐modality (CT<‐>MR) DIR algorithm performance and range. Due to the phantom multi‐imaging capabilities, other cross‐imaging DIR algorithms can now be explored.
TU‐AB‐202‐10: How Effective Are Current Atlas Selection Methods for Atlas‐Based Auto‐Contouring in Radiotherapy Planning?
Authors: Peressutti D , Schipaanboord B , van Soest J , Lustberg T , van Elmpt W , Kadir T , Dekker A , Gooding M
Published: July 2016

Purpose:

To investigate the effectiveness of atlas selection methods for improving atlas‐based auto‐contouring in radiotherapy planning.

Methods:

275 H&N clinically delineated cases were employed as an atlas database from which atlases would be selected. A further 40 previously contoured cases were used as test patients against which atlas selection could be performed and evaluated. 26 variations of selection methods proposed in the literature and used in commercial systems were investigated. Atlas selection methods comprised either global or local image similarity measures, computed after rigid or deformable registration, combined with direct atlas search or with an intermediate template image. Workflow Box (Mirada‐Medical, Oxford, UK) was used for all auto‐contouring. Results on brain, brainstem, parotids and spinal cord were compared to random selection, a fixed set of 10 “good” atlases, and optimal selection by an “oracle” with knowledge of the ground truth. The Dice score and the average ranking with respect to the “oracle” were employed to assess the performance of the top 10 atlases selected by each method.

Results:

The fixed set of “good” atlases outperformed all of the atlas‐patient image similarity‐based selection methods (mean Dice 0.715 c.f. 0.603 to 0.677). In general, methods based on exhaustive comparison of local similarity measures showed better average Dice scores (0.658 to 0.677) compared to the use of either template image (0.655 to 0.672) or global similarity measures (0.603 to 0.666). The performance of image‐based selection methods was found to be only slightly better than a random (0.645). Dice scores given relate to the left parotid, but similar results patterns were observed for all organs.

Conclusion:

Intuitively, atlas selection based on the patient CT is expected to improve auto‐contouring performance. However, it was found that published approaches performed marginally better than random and use of a fixed set of representative atlases showed favourable performance.

This research was funded via InnovateUK Grant 600277 as part of Eurostars Grant E!9297.

DP,BS,MG,TK are employees of Mirada Medical Ltd.
TU‐AB‐209‐02: Designing Model Observers for Signal‐Known‐Exactly Tasks in Digital Breast Tomosynthesis
Authors: Park S.
Published: July 2016

Digital breast tomosynthesis (DBT), a limited‐angle tomographic technique by its nature has multiple optimal system configurations, which can lead to many potential changes to the existing and new DBT systems entering the US market. With the availability of computational tools such as for modeling imaging physics, it is becoming increasingly important to conduct virtual trials for a rigorous, preclinical and task‐based assessment of DBT. For such virtual assessment to be successful, it is critical to: (1) develop model‐observer approaches that can account for patient data statistics stemming from realistic or real breast backgrounds as well as lesion characteristics, thereby performing given tasks effectively and (2) validate the model‐observer approaches and their performance trends/levels with physical measurements from a prototype or real DBT system and a physical phantom ensemble. It is also important to understand trade‐offs between patient (phantom) sample/effect size and observer performance reliability for gaining knowledge on how to choose appropriate model observers for the given tasks. In this session, a variety of model‐observer approaches associated with currently available breast phantoms (either physical or virtual) and their sample size will be discussed. The presenters in this session will also discuss the limitations of each model observer approach to provide an understanding of the circumstances where each of these approaches can be more suitable than the others. The session is organized as follows: First, the development of virtual and physical phantoms that mimic breast anatomy will be presented. This will be followed by two presentations on model observers for DBT, one on the designing of model observers for signal‐known‐exactly (SKE) tasks and another on the development of visual search based model observers with the intent of identifying useful image features. Finally, this will be followed by practical examples where such model observers are applied to digital breast tomosynthesis.
TU‐AB‐209‐03: Identifying Useful Features for Visual‐Search Model Observers
Authors: Gifford H.
Published: July 2016

Digital breast tomosynthesis (DBT), a limited‐angle tomographic technique by its nature has multiple optimal system configurations, which can lead to many potential changes to the existing and new DBT systems entering the US market. With the availability of computational tools such as for modeling imaging physics, it is becoming increasingly important to conduct virtual trials for a rigorous, preclinical and task‐based assessment of DBT. For such virtual assessment to be successful, it is critical to: (1) develop model‐observer approaches that can account for patient data statistics stemming from realistic or real breast backgrounds as well as lesion characteristics, thereby performing given tasks effectively and (2) validate the model‐observer approaches and their performance trends/levels with physical measurements from a prototype or real DBT system and a physical phantom ensemble. It is also important to understand trade‐offs between patient (phantom) sample/effect size and observer performance reliability for gaining knowledge on how to choose appropriate model observers for the given tasks. In this session, a variety of model‐observer approaches associated with currently available breast phantoms (either physical or virtual) and their sample size will be discussed. The presenters in this session will also discuss the limitations of each model observer approach to provide an understanding of the circumstances where each of these approaches can be more suitable than the others. The session is organized as follows: First, the development of virtual and physical phantoms that mimic breast anatomy will be presented. This will be followed by two presentations on model observers for DBT, one on the designing of model observers for signal‐known‐exactly (SKE) tasks and another on the development of visual search based model observers with the intent of identifying useful image features. Finally, this will be followed by practical examples where such model observers are applied to digital breast tomosynthesis.
TU‐B‐201‐03: Accounting for MV Imaging Dose and the Future of MV Imaging
Authors: Flynn R.
Published: July 2016

Radiotherapy is in the era of image guided radiation therapy (IGRT) in which imaging procedures are routinely performed for patient positioning, and target localization. The additional imaging dose delivered may increase risk to the patient and therefore needs to be managed. This lecture provides an overview of the AAPM TG‐180 which is charged with: providing an overview on imaging dose including megavoltage electronic portal imaging (MV EPI), kilovoltage digital radiography (kV DR), Tomotherapy MV‐CT, megavoltage cone‐beam CT (MV‐CBCT) and kilovoltage cone‐beam CT (kV‐CBCT) as well as providing general guidelines for commissioning and managing imaging dose calculations. The dose to radiotherapy (RT) patients resulting from different image guidance procedures is reviewed and recommendations for managing the imaging dose are provided. Different techniques for reducing the image guidance dose are summarized. A recommended threshold beyond which imaging dose should be considered in the treatment planning process is discussed. This lecture also discusses kilovoltage imaging dose determination by calculation and estimation, and inclusion in treatment planning as well as accounting for MV imaging dose and the future of MV imaging.

Learning Objectives:

Learn the different image guidance modalities, typical organ doses resulting from different image procedures, and techniques to reduce the imaging dose;

Understand the imaging dose threshold and rationale for accounting for the imaging dose;

Learn how to account for kV imaging dose

Learn how to account for MV imaging dose and understand the future of MV imaging
TU‐D‐204‐00: The Gadget: Making of the Atomic Bomb
Authors: Reiser Ingrid
Published: July 2016

Making of the Atomic Bomb

2015 is the 70th anniversary of the detonation of the first atomic bomb. Since then, few scientific issues have aroused so much public controversy as the effects of radiation. This lecture will present the extraordinary historical genesis and the thoughts of great men and women in the development of the atomic bomb. In addition, the difficult military and political decisions will be covered such as: target selection, the debate over whether to give the Japanese government a demonstration of its power and whether to use it at all. Also, were the German and Japanese scientists developing there own bomb? Declassified top secret documents now help in answering some of these questions.
TU‐D‐204‐01: Making of the Atomic Bomb
Authors: Strubler K.
Published: July 2016

Making of the Atomic Bomb

2015 is the 70th anniversary of the detonation of the first atomic bomb. Since then, few scientific issues have aroused so much public controversy as the effects of radiation. This lecture will present the extraordinary historical genesis and the thoughts of great men and women in the development of the atomic bomb. In addition, the difficult military and political decisions will be covered such as: target selection, the debate over whether to give the Japanese government a demonstration of its power and whether to use it at all. Also, were the German and Japanese scientists developing there own bomb? Declassified top secret documents now help in answering some of these questions.
TU‐D‐201‐04: Veracity of Data Elements in Radiation Oncology Incident Learning Systems
Authors: Kapur A , Evans S , Brown D , Ezzell G , Hoopes D , Dieterich S , Kapetanovic K , Tomlinson C
Published: July 2016

Purpose:

Incident learning systems encompass volumes, varieties, values, and velocities of underlying data elements consistent with the V's of big data. Veracity, the 5th V however exists only if there is high inter‐rater reliability (IRR) within the data elements. The purpose of this work was to assess IRR in the nationally deployed RO‐ILS: Radiation Oncology‐Incident Learning System (R) sponsored by the American Society for Radiation Oncology (ASTRO) and the American Association of Physicists in Medicine (AAPM).

Methods:

Ten incident reports covering a wide range of scenarios were created in standardized narrative and video formats and disseminated to 67 volunteers of multiple disciplines from 26 institutions along with two published narratives from the International Commission of Radiological Protection to assess IRR on a nationally representative level. The volunteers were instructed to independently enter the associated data elements in a test version of RO‐ILS over a 3‐week period. All responses were aggregated into a spreadsheet to assess IRR using free‐marginal kappa metrics.

Results:

48 volunteers from 21 institutions completed all reports in the study period. The average kappa score for all raters across all critical data elements was 0.659 [range 0.326–1.000]. Statistically significant differences (p <0.05) were noted between reporters of different disciplines and raters with varying levels of experience. Kappa scores were high for event classification (0.781) and contributory factors (0.777) and low for likelihood‐of‐harm (0.326). IRR was highest among AAPM‐ASTRO members (0.672) and lowest among trainees (0.463).

Conclusion:

A moderate‐to‐substantial level of IRR in RO‐ILS was noted in this study. Although the number of events reviewed in this study was small, opportunities for improving the taxonomy for the lower scoring data elements as well as specific educational targets for training were identified by assessing data veracity quantitatively. This is expected to improve the quality of the data garnered from RO‐ILS.
TU‐D‐201‐05: Validation of Treatment Planning Dose Calculations: Experience Working with MPPG 5.a
Authors: Xue J , Park J , Kim L , Balter P , Ohrt J , Kirsner S , Wang C , Ibbott G
Published: July 2016

Purpose:

Newly published medical physics practice guideline (MPPG 5.a.) has set the minimum requirements for commissioning and QA of treatment planning dose calculations. We present our experience in the validation of a commercial treatment planning system based on MPPG 5.a.

Methods:

In addition to tests traditionally performed to commission a model‐based dose calculation algorithm, extensive tests were carried out at short and extended SSDs, various depths, oblique gantry angles and off‐axis conditions to verify the robustness and limitations of a dose calculation algorithm. A comparison between measured and calculated dose was performed based on validation tests and evaluation criteria recommended by MPPG 5.a. An ion chamber was used for the measurement of dose at points of interest, and diodes were used for photon IMRT/VMAT validations. Dose profiles were measured with a three‐dimensional scanning system and calculated in the TPS using a virtual water phantom.

Results:

Calculated and measured absolute dose profiles were compared at each specified SSD and depth for open fields. The disagreement is easily identifiable with the difference curve. Subtle discrepancy has revealed the limitation of the measurement, e.g., a spike at the high dose region and an asymmetrical penumbra observed on the tests with an oblique MLC beam. The excellent results we had (> 98% pass rate on 3%/3mm gamma index) on the end‐to‐end tests for both IMRT and VMAT are attributed to the quality beam data and the good understanding of the modeling. The limitation of the model and the uncertainty of measurement were considered when comparing the results.

Conclusion:

The extensive tests recommended by the MPPG encourage us to understand the accuracy and limitations of a dose algorithm as well as the uncertainty of measurement. Our experience has shown how the suggested tests can be performed effectively to validate dose calculation models.
TU‐D‐201‐06: HDR Plan Prechecks Using Eclipse Scripting API
Authors: Palaniswaamy G , Morrow A , Kim S , Rangaraj D
Published: July 2016

Purpose:

Automate brachytherapy treatment plan quality check using Eclipse v13.6 scripting API based on pre‐configured rules to minimize human error and maximize efficiency.

Methods:

The HDR Precheck system is developed based on a rules‐driven approach using Eclipse scripting API. This system checks for critical plan parameters like channel length, first source position, source step size and channel mapping. The planned treatment time is verified independently based on analytical methods. For interstitial or SAVI APBI treatment plans, a Patterson‐Parker system calculation is performed to verify the planned treatment time. For endobronchial treatments, an analytical formula from TG‐59 is used. Acceptable tolerances were defined based on clinical experiences in our department. The system was designed to show PASS/FAIL status levels. Additional information, if necessary, is indicated appropriately in a separate comments field in the user interface.

Results:

The HDR Precheck system has been developed and tested to verify the treatment plan parameters that are routinely checked by the clinical physicist. The report also serves as a reminder or checklist for the planner to perform any additional critical checks such as applicator digitization or scenarios where the channel mapping was intentionally changed. It is expected to reduce the current manual plan check time from 15 minutes to <1 minute.

Conclusion:

Automating brachytherapy plan prechecks significantly reduces treatment plan precheck time and reduces human errors. When fully developed, this system will be able to perform TG‐43 based second check of the treatment planning system's dose calculation using random points in the target and critical structures. A histogram will be generated along with tabulated mean and standard deviation values for each structure. A knowledge database will also be developed for Brachyvision plans which will then be used for knowledge‐based plan quality checks to further reduce treatment planning errors and increase confidence in the planned treatment.
TU‐D‐201‐09: Is the MS Degree Still a Viable Option for Clinical Medical Physics Education and Training?
Authors: Loughery B , Burmeister J
Published: July 2016

Purpose:

Recent publications have questioned the value of the MS degree and its future in medical physics education. This study investigates the residency placement rate (RPR) for CAMPEP‐accredited MS programs as a metric to evaluate this degree as judged by residency programs.

Methods:

By CAMPEP Standard 2.10, accredited graduate programs must present placement data on their program webpage and update it annually. We used these data to calculate the RPR of 43 programs into CAMPEP‐accredited residency programs over a five year period (2010–2014). We further analyzed these rates by length of accreditation and degree program, when available. These placement data were validated against annual CAMPEP reports.

Results:

The cumulative RPR for MS graduates over the past five years is 22.4%. For individual programs, high placement was correlated with accreditation duration. Six graduate programs have never placed a resident – all were accredited after 2010. Of the 43 programs examined, only 4 have placed >40% of their graduates into residencies while placing at least 3 residents per year. These programs account for 39% of all MS residents placed, have a combined 51% placement for their MS graduates, and place MS graduates at rates significantly higher than the RPR for PhD graduates (36.2%). The RPR of the remaining 37 MS programs is 16%.

Conclusion:

The MS degree remains a viable option for clinical medical physics education and training, at least at several very successful programs. Thus, contrary to the perception among many entrants to medical physics education, one doesn't need a PhD to obtain a residency. However, prospective students are encouraged to carefully evaluate individual program statistics prior to entry. Moving forward, the profession should evaluate the relative success of MS medical physicists in both residency and clinical practice to determine whether to eliminate or cultivate this aspect of our educational infrastructure.
TU‐D‐201‐10: Ethics and Discriminatory Behavior in the MedPhys Match
Authors: Hendrickson K , Burmeister J , Rodrigues A , Juang T , Vimolchalao S
Published: July 2016

Purpose:

To investigate behaviors that may be in conflict with ethical standards of the Medical Physics Residency (MedPhys) Match process and with best practices for adhering to non‐discrimination regulations of the Equal Employment Opportunity Commission (EEOC).

Methods:

A confidential survey was sent to registered applicants and program directors for the 2014/2015 MedPhys Match. Survey questions included demographics, application, interview and post‐interview experiences, match results, and overall satisfaction with the process.

Results:

Of the 402 candidates emailed, 109 completed the survey. 48% of the respondents did match with a residency position in 2015. Of the 77 program directors emailed, 42 completed the survey. Selected results of the surveys are included. 69% of candidate respondents indicated that they were asked during interviews where else they were interviewing; 31.7% of those respondents indicated that they were uncomfortable or very uncomfortable answering. 40% of candidate respondents (39% of males, 41% of females) indicated that they were asked about their marital or relationship status. 23% of the respondents (19% of males, 33% of females) indicated that they were asked about children or plans to have children. 57% who were asked this question (27% of males, 89% of females) indicated that they were uncomfortable/very uncomfortable answering. 29% were told by a program that they were “ranked to match” or told their rank prior to the match deadline. Only 13% indicated that they were asked by a program how highly they were going to rank that program or asked which program they would rank number one. Among that 13%, 64% indicated that they were uncomfortable/very uncomfortable answering.

Conclusion:

In the inaugural year of the MedPhys Match, there were instances of ethical violations and discriminatory interviewing. Training on the Match rules and EEOC guidelines can decrease these instances and thereby increase the fairness of the residency selection process.
TU‐D‐BRB‐02: Dual‐Energy CT: Applications in Oncologic Imaging
Authors: Schoepf U.
Published: July 2016

Dual‐energy CT technology is becoming increasingly available to the medical imaging community. In addition, several models of CT simulators sold for use in radiation therapy departments now feature dual‐energy technology. The images provided by dual‐energy CT scanners add new information to the radiation treatment planning process; multiple spectral components can be used to separate and identify material composition as well as generate virtual monoenergetic images. In turn, this information could be used to investigate pathologic processes, separate the properties of contrast agents from soft tissues, assess tissue response to therapy, and other applications of therapeutic interest. Additionally, the decomposition of materials in images could directly integrate with and impact the accuracy of dose calculation algorithms.

This symposium will explore methods of generating dual‐energy CT images, spectral and image analysis algorithms, current and future applications of interest in oncologic imaging, and unique considerations when using dualenergy CT images in the radiation treatment planning process.

Learning Objectives:

Understand acquisition techniques and processing algorithms used in dual‐energy CT imaging.

Discover current and future applications of dual‐energy CT images in the radiological oncology setting.

Introduce some of the unique considerations and QA requirements when integrating a dual‐energy CT scanner into the radiation therapy environment.

N. Pelc: GE Healthcare, Philips Healthcare, Sony; U. Schoepf: Consultant for and / or research support from Astellas, Bayer,;Bracco, GE, Guerbet, Medrad, Siemens
TU‐D‐202‐03: Gating Is the Best ITV Killer
Authors: Low D.
Published: July 2016

Respiratory motion has long been recognized as an important factor affecting the precision of radiotherapy. After the introduction of the 4D CT to visualize the respiratory motion in 3D, the internal target volume (ITV) has been widely adopted as simple method to take the motion into account in treatment planning and delivery. The ITV is generated as the union of the CTVs as the patient goes through the respiratory cycle. Many issues have been identified with the ITV. In this session three alternatives for the ITV will be discussed: 1) An alternative motion‐inclusive approach with better imaging and smaller margins, called mid‐position CT. 2) The tracking approach and 3) The gating approach.

The following topics will be addressed by Marcel van Herk (“Is ITV the correct motion encompassing strategy”): Magnitude of respiratory motion, effect of motion on radiotherapy, motion encompassing strategies, and software solutions to assist in motion encompassing strategies. Then Paul Keall (“Make margins simple: Use real‐time target tracking”) will discuss tracking with: clinical drivers for tracking, current clinical status of tumor tracking, future tumor tracking technology, and margin margin challenges with and without tracking. Finally Daniel Low will discuss gating (“Gating is the best ITV killer”): why ITV in the first place, requirements for planning, requirements at the machine, benefits and costs.

The session will end with a discussion and live demo of motion simulation software to illustrate the issues and explain the relative benefit and appropriate uses for the three methods.

Learning Objectives:

Explain the 4D imaging and treatment planning process.

Summarize the various approaches to deal with respiratory motion during radiotherapy

Discuss the tradeoffs involved when choosing one of the three discussed approaches.

Explain in which situation each method is the best choice

Research is partly funded by Elekta Oncology Systems and the Dutch Cancer Foundation; M. van Herk, Part of the research was funded by Elekta Oncology Systems and the Dutch Cancer Foundation
TU‐D‐206‐00: Body Tomosynthesis
Authors: Flynn Michael
Published: July 2016

The current use of tomosynthesis for musculo‐skeletal, abdominal, and thoracic imaging will be considered in four sections:

A. Current Practice (M. Bath) : The presently available systems for body tomosynthesis will be reviewed and the current diagnostic applications described.

B. Image Features and artifacts (M. FLynn): The consequence of a limited angle linear acquisition scan on image features and artifacts will be explained.

C. Radiation Dose (J. Sabol): The organ dose associated with common tomosynthesis protocols will be reported and compared to the dose for radiographic and computed tomography procedures.

D. Acceptance testing and Quality Assurance (K. Jones): Recommended medical physics acceptance test will be described and appriate programs for quality assurance discussed.

Learning Objectives:

Learn how body tomosynthesis is currently being used in diagnostic radiology.

Understand how scan acquisitions can be designed to optimize image content and minimize artifacts.

Learn to radiation dose associated with common protocols.

Understand how to best evaluate a newly purchased tomosynthesis system.

J. Sabol, Presenter is an employee of GE Healthcare.
TU‐D‐209‐01: Dosimetry of Diagnostic Work Up Mammography
Authors: Jallow N , Sechopoulos I
Published: July 2016

Purpose:

To investigate patient average glandular dose (AGD) characteristics of diagnostic mammography.

Methods:

The techniques used to image 14420 patients who received diagnostic work up mammography from October 2008 to December 2014 at one academic hospital were retrospectively collected. The most common diagnostic views and the techniques used for each according to compressed breast thickness were determined. For all techniques, 1st half value layer and air kerma output per tube current‐exposure time product were measured; then the incident air kerma for each acquisition was calculated. The values for normalized glandular dose (DgN) were obtained with a validated Monte Carlo simulation of mammographic acquisition. The mono‐energetic DgN results were combined according to relative fluence using the TASMICS model to obtain DgN coefficients for each spectrum. The spectral DgN and calculated incident air kerma were used to estimate AGD of patients with breast thickness ranging from 2 to 8 cm.

Results:

The most common views utilized during diagnostic mammography were magnification craniocaudal (24%), magnification mediolateral (19%), spot craniocaudal (28%), and spot mediolateral oblique (24%). The AGD increased with increasing breast thickness for both the magnification and spot views. The AGD for a 5.5 cm thick breast was approximately 6.8 mGy and 2.2 mGy for the magnification and spot views, respectively. The AGD ranged from 3.6 mGy to 6.8 mGy for the magnification views and from 1.0 mGy to 3.1 mGy for spot views. The difference in AGD between the two magnification views or the two spot views was not significant.

Conclusion:

These results provide information on breast dose to which screening recalled women are exposed to. In addition to understanding the dose used for common clinical imaging tests, this data could be used when comparing use of mammography for diagnostic workup to other potential modalities, such as breast tomosynthesis and breast CT.
TU‐D‐PinS Room/Hall E‐00: Digital Breast Tomosynthesis I
Authors: Sammet Christina
Published: July 2016

This session along with the others on Digital Breast Tomosynthesis (DBT) offered at this years meeting as part of the Educational, Scientific and Partners in Solutions is intended to meet the FDA requirements for physicists to survey a DBT system. Specifically, this vendor offered session held as part of the Partners in Solutions is also meant to focus on those requirements. This session is being done along with the other two vendors of approved DBT systems in order to cover the machine specific features of those systems.

Learning Objectives:

Meet FDA requirement of introducing vendor specific features of this respective DBT system
TU‐FG‐204‐01: An Overview of ACR, Joint Commission, and the AAPM Practice Guidelines On CT Protocol Optimization
Authors: Szczykutowicz T.
Published: July 2016

The role of a medical physicist involved with clinical CT activities is changing rapidly. No longer is the physicist responsible for simply ensuring scanner QA. This shift is evident by looking at the trend to regulate more and more aspects of what activities must be performed to keep a CT practice within compliance. In this symposium, new guidelines from the ACR, Joint Commission, and several states will be addressed. An overview of these regulations will be provided. Then, three speakers will provide an in‐depth account of how their CT protocol Optimization team functions. Lastly, a representative from the Joint Commission will provide recent surveyor education, experience, and trend information.

Learning Objectives:

Understand the ACR, Joint Commission, and aspects of several state regulations/guidelines related to the clinical practice of CT.

Learn how a CT protocol optimization is organized and what tasks physicists perform from the perspective of four different institutions.

T. Szczykutowicz, TPS provides CT protocols to GE Healthcare under a license agreement. TPS receives grant support from GE Healthcare.
TU‐FG‐204‐03: An Overview of the CT Protocol Optimization Team at The University of Washington
Authors: Kanal K.
Published: July 2016

The role of a medical physicist involved with clinical CT activities is changing rapidly. No longer is the physicist responsible for simply ensuring scanner QA. This shift is evident by looking at the trend to regulate more and more aspects of what activities must be performed to keep a CT practice within compliance. In this symposium, new guidelines from the ACR, Joint Commission, and several states will be addressed. An overview of these regulations will be provided. Then, three speakers will provide an in‐depth account of how their CT protocol Optimization team functions. Lastly, a representative from the Joint Commission will provide recent surveyor education, experience, and trend information.

Learning Objectives:

Understand the ACR, Joint Commission, and aspects of several state regulations/guidelines related to the clinical practice of CT.

Learn how a CT protocol optimization is organized and what tasks physicists perform from the perspective of four different institutions.

T. Szczykutowicz, TPS provides CT protocols to GE Healthcare under a license agreement. TPS receives grant support from GE Healthcare.
TU‐E‐TOUR‐I‐01: Dosimters for QC in Diagnostic Imaging
Authors: Jiang X.
Published: July 2016

Tour Leader: Xia Jiang, Ohio State University, Columbus, OH

Tour Guides:

Xia Jiang, Ohio State University, Columbus, OH

Kevin Little, The University of Chicago, Chicago, IL

Christina Sammet, Lurie Children's Hospital of Chicago, Chicago, IL

Participating Vendors:

IBA

PTW ‐ New York

Radcal Corporation

RTI Electronics, Inc.

Exhibit Hall Guided Tours is a new program launching this year at the Annual Meeting. The Guided Tours are designed to enhance the interaction between meeting attendees and exhibitors. This year's Imaging Guided Tours are organized around the theme of dosimeters for quality control in diagnostic imaging. Tours will begin with an introduction and background given by Dr. Xia Jiang, the Tour Leader. The introduction will cover the types and properties of different radiation dosimeters used for quality assurance in clinical radiology. Attendees will then break into smaller groups, each lead by an AAPM‐member Tour Guide. The tour groups will visit the exhibit booths of vendors who provide appropriate dosimeters, and a vendor representative will give a presentation to the group about their particular product(s). The vendor representatives as well as the Tour Guides will be available to answer questions.

Outline:

Types and properties of radiation detectors and dosimeters

Ionization chamber dosimeters

Solid state dosimeters

Dosimeter calibration: Primary and secondary standards dosimetry laboratories

Instruments for measuring tube voltage and exposure time

Vendor presentations will likely cover features and innovations of different dosimeter systems, as well as their practical use.

Learning Objectives:

Understand the types and properties of different instrumentations used for quality control in diagnostic imaging.

Understand the process of dosimeter calibration.

Gain familiarity with the latest commercial dosimeter systems from different vendors.
TU‐H‐201‐06: Panel Discussion Member
Authors: Pavord D.
Published: July 2016

The New New Symposium is a symposium for members relatively new to the organization to learn about the organizational structure and operational procedures of the society; how decisions are made, how the council and committee leadership is appointed and operates, opportunities for volunteer involvement, and a brief overview of the services and efforts provided by the HQ staff and the website. Attendees will hear from council chairs, key staff and chairs, and members with volunteer experience.

After the symposium a social hour ensues with opportunities to interact with key AAPM members. The New Member Symposium is a (free) ticket option when you register online for the Annual Meeting. And don't forget registrants receive one (free) ticket for a beverage of your choice during the social afterwards.
TU‐H‐204‐00: Work of ICRP, NCRP and Others and How They Impact On Medical Physicists
Authors: Rehani Madan
Published: July 2016

Since 1928, the International Commission on Radiological Protection (ICRP) has developed, maintained, and elaborated the International System of Radiological Protection used world‐wide as the common basis for radiological protection standards, legislation, guidelines, programs, and practice. ICRP provides and periodically revises radiation and tissue weighing factors, provides and updates recommended dose limits for occupational and public exposures, recommends dose levels for termination of pregnancy, and estimates threshold doses for tissue reactions (deterministic effects). ICRP developed the dose quantity “effective dose”.

NCRP Council Committee 1 (CC‐1) is charged with developing recommendations for revising radiation protection guidance for the United States. Topics to be discussed include a summary of current ICRP guidance, NCRP CC‐1 directions, NRC regulatory changes on the horizon, and potential implications of radiation protection guidance changes on the practice of medicine. The opinions of AAPM members on potential changes are welcomed.

NCRP Program Area Committee (PAC) 4 has oversight of activities in radiation protection in medicine, including protection of patients and training of health care workers. Documents have been published recently on diagnostic reference levels and achievable doses, health effects of preconception and prenatal radiation exposure, and administrative policies for quality assurance and peer review of tissue reactions associated with fluoroscopically guided interventions. Additional documents are in preparation.

Learning Objectives:

To understand the international system of radiation protection and learn about the work of the International Commission on Radiological Protection (ICRP) in relation to activities of medical physicists

To understand the ongoing work of NCRP in developing new guidance for radiation protection in the U.S.

To understand the ongoing work of NCRP in developing new recommendations for radiation protection in medicine.

To learn about other national organizations in US whose work plays a useful role in the activities of medical physicists.

M. Rehani, Work done as part of being member of ICRP. ICRP is an independent charity.