bluuebunny/crossref_metadata_2025_split huggingface dataset:
TU‐G‐301‐01: Practical Contouring: Prostate and H&N Anatomies
Authors: Wu J , Hsu I , Smith J 
Published: November 2011

In the last decade IMRT and related treatment modes have become de facto, if not actual standards of care. These modes are heavily dependent on the anatomical modeling phase of treatment planning. It may in fact be argued that this is the most important step in the planning process, as the optimization and plan evaluation will be directly affected by a good or poor anatomical model. Physicists have increasingly been called upon to do much of this contouring, yet have traditionally had only a brief formal introduction to anatomy. This session will provide a brief overview and refresher on two anatomical regions that have come to be most often treated by IMRT and like modalities.Dr. Jonn Wu will discuss the contouring of prominent normal structures and target volumes in the head and neck using multiple imaging modalities, and illuminate key concepts in identifying these structures. Dr. I‐Chow Hsu will discuss the structures in the pelvis relevant to prostatic treatments, including pelvic lymphatic chains, using CT and the Visible Human Project.Learning Objectives:1. To better understand how to identify structures in the head and neck2. To better understand how to identify structures in the pelvis relevant to prostate treatments3. To understand the impact and pitfalls of different imaging modalities in these anatomical locations.
WE‐A‐220‐01: Current Status of HIFU Therapy for Treatment of Benign and Malignant Tumors of the Abdomen, Pelvis and Bone
Authors: Hwang J 
Published: November 2011

High‐intensity focused ultrasound (HIFU) is a noninvasive method currently being investigated to treat certain primary solid tumors, metastatic disease, and enhance drug delivery. The field of medicine is evolving towards increasing use of noninvasive and minimally invasive therapies such as HIFU. The application of HIFU for tumor therapy has recently been gaining momentum due to advances in imaging technology such as magnetic resonance thermometry and advanced ultrasound imaging techniques that permit real‐time monitoring of HIFU treatment effects. Currently, several commercially available HIFU devices are manufactured worldwide for treatment of a wide variety of both benign and malignant tumors including uterine fibroids, prostate cancer, pancreatic cancer, liver tumors, thyroid tumors and other solid tumors that are accessible to ultrasound energy. Although HIFU technology has been used clinically since the 1950ˈs it remains a new therapeutic technology requiring further laboratory and clinical evaluation. This presentation provides an overview of the current status of clinical applications of HIFU for benign and malignant tumors within the abdomen and pelvis as well as treatment of bone metastasis.Learning Objectives:1. Understand the mechanisms that HIFU induces a biologic effect2. Understand the current limitations of ultrasound and MR‐guided HIFU therapy3. Understand the anatomic requisites and limitations for HIFU therapy
WE‐B‐BRA‐01: TG‐142: Quality Assurance for Medical Accelerators
Authors: Klein E 
Published: November 2011

The task group (TG) for quality assurance of medical accelerators was constituted by the American Association of Physicists in Medicineˈs Science Council, under the direction of the Radiation Therapy Committee and the Quality Assurance and Outcome Improvement Subcommittee. The report was published in the Journal of Medical Physics in September of 2009. [http://aapm.org/pubs/reports/RPT_142.pdf] The task group (TG #142) had two main charges. First to update, as needed, recommendations of Table II of the AAPM TG ▭ 40 Report on Quality Assurance, and second, to add recommendations for Asymmetric Jaws, Multileaf Collimation (MLC), and Dynamic/Virtual Wedges. The TG accomplished the update to TG▭40, specifying new test and tolerances, and has added recommendations for not only the new ancillary delivery technologies, but also for imaging devices that are part of the linear accelerator. The imaging devices include x▭ray imaging, photon portal imaging, and cone▭beam CT. The TG report was designed to account for the types of treatments delivered with the particular machine. For example, machines that are used for radiosurgery treatments, or intensity modulated radiotherapy (IMRT) require different tests and/or tolerances. There are specific recommendations for MLC quality assurance for machines performing IMRT. There are specific tables according to daily, monthly, and annual reviews, along with unique tables for wedge systems, MLC, and imaging checks. The report is geared to be flexible for the physicist to customize the QA program depending on clinical utility. This is consistent with the philosophy of TG▭100, “Method for Evaluating QA Needs in Radiation Therapy.” The report also gives recommendations as to action levels for the physicists to implement particular actions, whether they are inspection, scheduled action, or immediate and corrective action. The report also gives specific implementation recommendations regarding setup of a QA program by the physicist, such as; building a QA team, establishing procedures, training of personnel, documentation, and end▭to▭end system checks. The tabulated items of this report have been considerably expanded as compared with the original TG 40 report and the recommended tolerances accommodate differences of the intended functionality (i.e., non▭IMRT, IMRT, or Stereotactic Delivery).Learning Objectives:1. To understand the updates to TG▭40 in the new TG▭142 report.2. To understand the recommend QA tests for wedge, MLC, and imaging systems as they pertain to accelerator type and procedures performed (i.e. IMRT).3. To understand the implementation plan and action level and response recommendations
WE‐B‐220‐02: Advances in MR for Guidance of US Therapy
Authors: Butts‐Pauly K , Kaye E , Holbrook A , Bitton R 
Published: November 2011

Image guidance of focused ultrasound therapy is important for targeting the therapy, ensuring treatment and safety, and for assessing the therapy. This presentation will describe recent advances in these areas of the MR guidance of focused ultrasound.Accurate focusing of the ultrasound beam to the target tissue can be done with a low temperature rise “test shot.” Alternatively, imaging the acoustic radiation force allows visualization of the focal spot without a temperature rise. MR imaging of the acoustic radiation force displacement (MR‐ARFI) relies on the application of the ultrasound during a portion of a series of gradient lobes. In areas where the tissue is displaced, the water spins experience a different magnetic field and accumulate phase, which is not fully refocused at the time of signal measurement. The visualization of the focal spot can thus be achieved without a temperature rise.In addition to straightforward visualization of the focal spot, MR‐ARFI can provide a means for image feedback when correcting phase aberrations from the skull. An iterative method allows modification of transducer phases while maximizing the displacement at the focus. A non‐iterative method requires the MR‐ARFI measurements to be made, followed by a matrix inversion.For tissue ablation, MR thermometry can be used to accurately monitor tissue temperature. MR thermometry can be very sensitive to motion, including motion of the treated tissue or even motion of tissue in the vicinity of the treated tissue (such as due to respiration). Temperature imaging methods must be robust to these types of motions and solutions include multibaseline, referenceless, and hybrid multibaseline/referenceless approaches. Another important task for MR guidance is in beam steering in moving organs, such as the liver and kidneys.This can be done based on imaging alone or on a combination of imaging and respiratory phase monitoring, such as can be done with the bellows.Lastly, there are a number of methods under investigation for the visualization of ablated tissue. MR‐ARFI is a potential candidate. The acoustic radiation force displacement depends both on the ultrasound intensity and on the displacement of the tissue, which in the latter case ARFI relies on tissue displacement by the ultrasound beam, which is related to the tissue stiffness. Evaluating the change in tissue stiffness provides the spatial extent of the thermal ablation. Other evaluative imaging methods includes contrast enhanced MRI, which visualizes disruption of perfusion, and diffusion‐weighted MRI, which demonstrates a 36% decrease in ADC in the ablated tissue.Learning Objectives1. Understand the basis for acoustic radiation force imaging and its applications2. Understand the current research in the image guidance of focused ultrasound
WE‐C‐224‐02: The Clinical Medical Physics Situation in Africa
Authors: Ige T , Nakatudde R , Seddik Aibn , Khaled M 
Published: November 2011

Medical Physics in Africa has evolved over the last half a century from the Republic of South Africa in the southern tip of the continent to Ghana and Nigeria in the Western half and also Kenya, Uganda and United Republic of Tanzania in the Eastern sphere of the region and unto Algeria, Egypt, Morocco and Sudan in the Northern part.There is a wide disparity in terms of educational infrastructure and availability of equipment across this very wide geographical landscape to provide the required medical physics services particularly in the health establishments as well as the other areas where the expertise of this cadre of professionals are needed. In terms of human resources capability, the continent can only boast of a slightly more than 300 personnel employed in and around her health facilities and about 60% of these staff are domiciled in just three countries — Egypt, Morocco and Republic of South Africa.An attempt will be made in this paper to discuss the clinical medical physics issues both from the historical perspectives as well as the current state of affairs in the continent which culminated in the recent birth of the Federation of African Medical Physics Organisation (FAMPO) which has just been recently given a charter as the youngest regional body of the International Organisation of Medical Physics (IOMP).Learning Objectives:1. The Medical Physics infrastructure in terms of equipment and manpower.2. The Status of Education and Training in Africa.3. The gaps in the Medical Physics profession that FAMPO intends to address in the continent.
WE‐C‐224‐03: Medical Physics in Senegal: Status and Prospects
Authors: Gueye P , Ka O , Diagne M 
Published: November 2011

Senegal is one of the leading economies in the western sub‐Saharan region. Still, first‐class radiological equipments are lacking in the country. Radiation treatments are still done with 60Co sources and only a few x‐ray machines with limited capabilities are available for diagnostic imaging. This situation is compounded by maintenance issues that are not always easily overcome, due to lack of adequate funds devoted to this aspect of the running of a medical infrastructure. On the other hand, specialized personnel are also needed, in particular medical physicists. The situation has a serious impact on the health care of patients in this country.An ongoing effort to establish in Senegal an international interdisciplinary center is expected to contribute in solving the many issues existing in the field of medical physics. Indeed, the center will offer a strong medical physics component, with diagnosis and treatment tools as well as educational programs aimed at providing the basis for the improvement of health care.This communication will present the current status of medical physics in Senegal together with the interdisciplinary center project and its impact in health care in this country and beyond, in particular in Western Africa.
WE‐C‐BRB‐03: Feasibility Study for Total Marrow Irradiation with RapidArc Volumetric Arc Therapy (VMAT‐TMI)
Authors: Surucu M , Yeginer M , Kavak G , Fan J , Aydogan B 
Published: November 2011

Purpose: To investigate the dosimetric feasibility of VMAT‐TMI technique in terms of treatment planning and delivery efficiency and accuracy for a Rando phantom using Eclipse RapidArc technology. Methods: Total body irradiation (TBI) has been an integral part of pre‐conditioning regimens for the treatment of hematologic malignancies. Normal tissue toxicity is a common complication of TBI inclusive regimens especially at doses higher than 12 Gy due to inhomogeneous and excessive dose to organs at risk (OARs). Fixed gantry linear accelerator (linac) and Tomotherapy intensity modulated total bone marrow (IM‐TMI) techniques have been reported to reduce doses to OARs. However, the treatment time of more than one hour with both techniques may limit their clinical application. Volumetric modulated arc therapy (VMAT) may be able to increase the treatment delivery efficiency while increasing the target conformality and reducing the radiation dose to OARs. In order to treat all the bones in the Rando phantom, three sub‐plans with a total of nine arcs were used. A total of 100 thermoluminescent detectors (TLDs) were placed at 39 positions throughout the phantom. The measured TLD doses were compared to the calculated plan doses. Planar dose for each arc was verified using MapCheck and MapPhan. Results: Excellent target coverage with the prescription dose and dose reduction to the OARs were achieved similar to the fixed gantry linac IM‐TMI technique. The number of monitor units was decreased by 50%, while the delivery efficiency increased by more than 60%. TLD readings demonstrated accurate dose delivery, with a median dose difference of 0.5% from the calculated dose. Planar dose distributions of all arcs satisfied the 3% and 3 mm gamma criteria with an average pass rate of 97.8%. Conclusions: Results from this study suggest that RapidArc VMAT‐TMI technique is clinically feasible.This study is supported by Varian Medical Systems
WE‐C‐214‐08: Benefit of an Industrial Engineering Tool (Statistical Process Control) in Radiation Oncology: Clinical Experience
Authors: Palaniswaamy G , Rangaraj D , Yaddanapudi S , DeWees T , Brame S , Mutic S 
Published: November 2011

Purpose:1. Develop a tool for data collection, retrieval, visualization, real‐time feedback and advanced statistical analysis of IMRT QA process.2. Evaluate the need for site‐specific tolerances for IMRT QA.3. Timely identify systematic drifts in the IMRT QA measurements.Methods: Statistical process control (SPC) is a statistical tool that can be used to study process variations and evaluate process capability. This tool is applicable to IMRT QA processes. There are two causes of variation present in a process — common cause, which is the reason for random variation in the process, and special (assignable) cause, which is the reason for identifiable variation in the process. Process capability and control charts (S chart for process variability and EWMA chart to study the process mean) are two of the several tools available to study the process of interest. We use SPC and paperless environment for collection and processing of clinical IMRT QA data to create a tool for improved management of IMRT QA. Results: Automatic data collection, data validation and visualization are facilitated with the help of the developed tool. Data visualization and control charts are used to study the process variation and identify drifts and outliers. Process capability studies identify systematic variations present in the process and evaluate the need for site‐specific tolerances. For instance, process capability studies of the QA results for treatment plans using 6 MV X‐rays revealed a 1.1% variation in calibration and 0.5% variation in beam model and MLC leaf model. Conclusion: We have built a tool that collects data, analyzes them, plots S chart for process variability and EWMA charts. Process capability studies show that using a global tolerance for all different sites is not sufficient. Hence, we propose the use of 2 standard deviations for a 95% confidence level in the IMRT QA measurements.
WE‐E‐224‐04: Mental Preparation to Pass the ABR Board Certification in Radiological Physics
Authors: Stuller E 
Published: November 2011

Passing the Board Certification in Radiological Physics by the American Board of Radiology presents unique challenges in all 3 phases. Recognizing ones individual learning and testing styles is critical to success in each phase. Although individual learning styles may vary, brain healthy preparation, handling test anxiety, and acquiring effective copping skills is essential to success. This talk is designed to inspire self‐confidence by acquiring specific oral and written test taking techniques, recognizing anticipatory and situational anxiety, and developing coping skills needed to pass all three phases of the Boards.Learning Objectives:1. Learn brain healthy strategies in preparation for the boards.2. Recognize and develop coping skills for pre —test anxiety, anxiety during the exam and surviving posttest anxiety.3. Build self‐confidence through adequate test preparation by acquiring skills in self‐care, sleep hygiene, strategies to cope with internal and external distractions, time management testing skills, and physical and sedentary exercises during preparation.4. Learning to finish strong in all 3 phases of testing by learning and mastering the acquired skills of test taking in both the written and oral boards.
WE‐E‐BRB‐05: Characterization of a Novel DNA Dosimeter for Skin Dose Measurements
Authors: Wood T , Lewis BJ , Corcoran EC , Kerr A , Schreiner LJ 
Published: November 2011

Purpose: To develop a novel DNA dosimeter for accurate dose measurements in a broad spectrum of therapeutics beams including contaminated x‐ray fields. Methods: Monte Carlo simulations were used to evaluate the DNA dosimeter for surface dose detection. The dose deposited to the detector while on the surface of a cylindrical tissue phantom was compared to the dose deposited to the first 1 mm of skin along the beamˈs central axis for electrons and photons with energies 100 keV to 20 MeV. These results were combined with a theoretical derivation of the dosimeterˈs response to a broad spectrum of electron‐photon fields and compared to experimental results. Results: Results from the Monte Carlo simulations and theoretical derivation concluded that the DNA detector is capable of measuring skin doses with a 4.2% relative uncertainty. The experimental uncertainty in absorbed dose measurements was found to be 9%. The DNA dosimeter showed a linear signal response with dose in the range of 10 cGy to 10 Gy and the responses were statistically equal in cobalt 60 and 6 MV beams. Conclusions: The DNA dosimeter is theoretically capable of accurate absorbed dose measurements in therapeutic beam including skin dose measurements from contaminated x‐ray beams. Further experimental testing is required to determine if the dosimeter is independent of energy in a broad energy range of electron and photon fields and lower the experimental uncertainty.This work has been partially funded by the Chemical, Biological, Radiological‐Nuclear and Explosives Research and Technology Initiative (CRTI), project #06‐0186RD.
WE‐E‐BRB‐11: Radiation Hardness of the Storage Phosphor Europium Doped Potassium Chloride for Radiation Therapy Dosimetry
Authors: Driewer J , Chen H , Osvet A. , Sun B , Ice L , Low D , Li H 
Published: November 2011

Purpose: An important property of a reusable dosimeter is its radiation hardness, that is, its ability to retain its dosimetric merits after irradiation. The radiation hardness of europium doped potassium chloride (KCl:Eu2+), a storage phosphor material recently proposed for radiation therapy dosimetry, is examined in this study. Methods: Pellet‐style KCl:Eu2+ dosimeters, 6 mm in diameter and 1 mm thick, were fabricated in‐house for this study. The pellets were exposed by a 6 MV photon beam or in a high dose‐rate 137Cs irradiator. Macroscopic properties, such as radiation sensitivity, dose response linearity, and signal stability, were studied with a laboratory photostimulated luminescence (PSL) readout system. Since phosphor performance is related to the state of the storage centers and the activator, Eu2+, in the host lattice, spectroscopic and temporal measurements were carried out in order to explore radiation‐induced changes at the microscopic level. Results: KCl:Eu2+ dosimeters retained 40% of their initial signal strength after a 5000 Gy dose history. Sensitivity recovered to nearly 90% via a high‐temperature annealing procedure. Dose response was initially supralinear over the dose range of 50–500 cGy but became more linear with dose history. Measured data fit a linear approximation to within an average of 2% after 200 Gy to 5000 Gy dose history. There were no significant changes in the PSL stimulation spectra, PSL emission spectra, photoluminescence spectra, or luminescent lifetime, indicating that the PSL signal process remains intact after irradiation but at a reduced efficiency due to recoverable radiation‐induced perturbations in the crystal lattice. Conclusions: Systematic studies of KCl:Eu2+ material are important for understanding how the material can be optimized for radiation therapy dosimetry purposes. The data presented here indicate that KCl:Eu2+ exhibits strong radiation hardness and lends support for further investigations of this novel material.This work was supported in part by NIH Grant Nos. R21CA131690 and R01CA148853.