bluuebunny/crossref_metadata_2025_split huggingface dataset:
WE‐A‐BRCD‐01: Stereotactic Radiosurgery: State of the Art Technology and Implementation
Authors: Yenice K , Petti P , Dieterich S , Solberg T 
Published: June 2012

Since its introduction nearly 60 years ago, stereotactic radiosurgery has become the standard of care for the noninvasive destruction of intracranial tissues or lesions that may be inaccessible or unsuitable for open surgery. Today, modern stereotactic radiosurgery is practiced using advanced image guided treatment planning and specialized delivery systems including micro‐ MLC equipped linacs, CyberKnife, and Gamma Knife machines. Stereotactic radisourgery delivers a large dose to a precisely defined volume in a short time, and as such requires the utmost attention to precision and quality assurance. Also critical is the meticulous design of treatment processes that eliminate the possibility of potentially disastrous errors. In this presentation we review the fundamental aspects of stereotactic targeting and delivery, the technologies for stereotactic localization and treatment of cranial targets, and the quality assurance aspects associated with establishing and maintaining a clinical radiosurgery program. Examples of radiosurgery cases will be presented from the best practice sites utilizing Gamma Knife, CyberKnife, and linac delivery systems, followed by an expert panel discussion of quality measures for treatment planning and delivery.Learning Objectives:1. Differentiate how radiation is delivered for Gamma Knife, CyberKnife and Linac‐based (conventional and robotic) stereotactic radiosurgery.2. Define the treatment planning parameters, imaging requirements and workflow for Gamma Knife, CyberKnife and Linac‐based stereotactic radiosurgery.3. Discuss measures for assuring accuracy in stereotactic localization and dose delivery for Gamma Knife, CyberKnife and Linac‐based stereotactic radiosurgery.4. Discuss uncertainties and limitations associated with Gamma Knife, CyberKnife and Linac‐based stereotactic radiosurgery
WE‐A‐211‐01: Medical Physics in Latin America ‐ How Can the AAPM Help?
Authors: Pipman Y 
Published: June 2012

Purpose: 1) To examine current clinical and educational needs in Medical Physics in Latin America and recent AAPM efforts to meet them. 2) To assess how can AAPM be more effective in Latin America. Methods: Data from the region are used to update the needs for training and education of Medical Physicists vis‐à‐vis current and projected staffing needs. Developments in the state of practice, and upgrades of equipment, are considered in the assessment of needs. Activities and resources of the AAPM are appraised for their specific requirements and their potential effectiveness. Results: Several programs and local resources have been added or expanded in a number of countries since the last update in 2010. These concentrate mainly in Radiation Oncology Physics, where the perceived need is most evident. Current and projected staffing necessitate more extensive education, training and certification in most countries in Latin America. There is marked difference in utilization of Medical Physics services in imaging between the region and North America. Regulatory requirements and adoption of practice standards are uneven between and within countries. AAPM, and a considerable number of its members, have supported, participated and contributed to a variety of educational and professional activities carried out by local and regional organizations. Several of these involved collaboration with international organizations such as IAEA and IOMP. A smaller number of projects involved individual commitments for longer durations. These provide an insight into ways of enhancing and further developing regional capabilities. Conclusions: There is measurable growth in the regional capabilities to educate and train Medical Physicists in Radiation Oncology, with a slower pace of growth in Imaging. The introduction of new technologies and methods requires this pace to be accelerated in order to meet current and projected needs. The AAPM has significant human and organizational resources to offer and can make a meaningful contribution to expand this local capacity. There is a need to leverage its resources by increased collaboration and coordination with international organizations and to explore funding mechanisms from companies to augment these resources. Longer term projects and partnerships need to be developed.Learning Objectives:1. Understand the current needs for Education and Training in Latin America2. Assess the resources that the AAPM and its members can offer to support the regional programs3. Discuss ways for leveraging the AAPM resources for a sustained and effective effort to meet the regional needs
WE‐A‐213AB‐01: Second Cancers from Radiation Therapy Procedures
Authors: Kry S , Howell R 
Published: June 2012

Second Cancers are the most common late effect among long‐term cancer survivors. Radiation has been a known risk factor for cancer induction based on atomic bomb survivor follow‐up. Over the last few decades, there has also been increasing data on second cancers in medically exposed populations, particularly radiotherapy patients. As treatments become more successful and patients survive longer after treatment, long‐term patient health considerations must play an increasing role in the selection of treatment. To this end, it is important that the field of medical physics become well educated in issues related to long‐term radiotherapy sequelae, including second cancers. The session chair will give an overview of retrospective dose reconstruction method commonly used in these large cohort studies second cancers in patients treated with radiation therapy. Understanding the dosimetry in these studies will provide a better understanding of the results of the studies, the dose response models, and gaps in knowledge regarding dose volume effects. In the remainder of the presentation, the speaker will focus on the current state of knowledge of second cancers, specifically focusing on information and limitations of the available literature. This will include the magnitude of risk of second cancers, including the impact of different demographics. It will also include etiological discussions, focusing on the risk attributable to radiation. This presentation will include the available data on the dose response of second cancers, including the large uncertainties inherent to both low and high dose regions. It will also highlight dosimetry for advanced radiotherapy techniques, and what associated doses might mean for the second cancer risk. Finally, the presentation will discuss examples of how second cancer risk can be reduced in routine clinical practice. Learning Objectives: increase the knowledge of clinical medical physicists regarding radiation‐ induced second cancers as well as stimulate further research in this broad and increasingly important area.Learning Objectives:1. To provide general overview of the dose reconstruction methods used in epidemiological retrospective cohort studies of radiation related late effects.2. To improve the understanding of the magnitude of the second cancer risk faced by radiotherapy patients.3. To improve the understanding of the etiology of second cancers.4. To present an overview of current knowledge on dose response for radiation induced second cancers.5. To discuss the impact of advanced radiotherapy techniques on the risk of second cancers6. To provide examples of how second cancer risk can be reduced in routine clinical practice.
WE‐B‐213AB‐01: AAPM TG1S7: An Overview of Source Modeling and Beam Commissioning for Clinical Monte Carlo
Authors: Ma C 
Published: June 2012

The Monte Carlo method is the most accurate dose calculation method for radiotherapy treatment planning and several commercial vendors have implemented Monte Carlo dose calculation algorithms for photon and electron radiation therapy treatment planning. The AAPM task group 157 was formed to deal with the source modeling and beam commissioning issues for the clinical implementation of Monte Carlo algorithms and a report has been produced to summarize the source models used by the commercial vendors and the beam commissioning recommendations by TG 157. This is the first presentation of this educational session on the TG 157 report and related topics. A brief introduction will be given of the basics of Monte Carlo dose calculation and methods developed for source modeling and beam commissioning for clinical Monte Carlo dose calculation. This will be followed by a brief introduction to the TG157 report that will provide some background information on the two following presentations.Learning Objectives:1. Understand the basics of Monte Carlo radiation transport2. Understand the methods for Monte Carlo source modeling and beam commissioning3. Understand the goals and scope of the AAPM Task Group 157
WE‐B‐213AB‐02: AAPM TG‐157 Recommendations on Beam Commissioning for Clinical Monte Carlo Dose Calculation
Authors: Chetty IJ , Faddegon B , Ma C 
Published: June 2012

Monte Carlo (MC) dose calculation algorithms are currently available for routine clinical planning in several commercial treatment planning systems. As noted in the AAPM Task Group Report No. 105 on issues associated with clinical implementation of MC dose algorithms, there are several fundamental differences between MC and other algorithms that need to be considered in the clinical commissioning process. The AAPM Task Group 157 was formed to provide comprehensive information on the factors relevant to source modeling and beam commissioning of MC dose algorithms. The TG‐157 report was charged to provide prescriptive guidelines to medical physicists as they embark on acceptance testing and clinical commissioning of these algorithms prior to clinical use. This lecture will focus specifically on the topic of beam commissioningLearning Objectives:1. Understand the basic components of the MC dose algorithm which need to be considered during clinical commissioning. Understand the beam commissioning requirements associated with different beam models.2. Understand the types of verification measurements necessary for accurate clinical commissioning of MC beam models and the criteria for acceptable agreement between calculations and measurements.3. Understand the issues associated with accurate benchmark measurements for beam modeling, especially under circumstances of charged particle disequilibrium.
WE‐B‐213AB‐03: AAPM TG‐1S7: Commercial Implementation of Source Modeling and Beam Commissioning for Clinical Monte Carlo Dose Calculation
Authors: Faddegon B , Ma C , Chetty I 
Published: June 2012

Monte Carlo simulation for dose calculation is available in several commercial treatment planning systems. A range of source models and beam commissioning methodology is available with the different systems. Source models are currently analytical or hybrid models, combining Monte Carlo simulation with analytical approaches. The models are characterized by measurement. In this lecture, source modeling and beam commissioning for dose calculation with the Monte Carlo method employed in 5 commercial treatment planning systems will be reviewed. For x‐rays: iPlan (BrainLAB), Monaco (Elekta), and Multiplan (Accuray). For electrons: Eclipse (Varian Medical Systems), and Oncentra MasterPlan (Nucletron). The beam modeling approaches will be compared and contrasted, based on published source models and information provided by the vendors.Learning Objectives:1. Understand the different source models used in commercial planning systems for dose calculation with the Monte Carlo method.2. Understand how these source models are commissioned.
WE‐B‐213CD‐01: International Actions on Radiation Safety in Fluoroscopic Procedures Performed Outside Radiology Departments
Authors: Rehani M 
Published: June 2012

Fluoroscopic guided procedures are increasingly being performed outside main radiology departments particularly in operation theatres. In some procedures the patient dose per procedure falls in the range of 5 to 30 mSv of effective dose and in some others local radiation is high enough with risks of radiation induced skin injuries. Generally most fluoroscopy machines used in operation theatres do not have protective lead glass screens for operators and other staff and thus there is possibility of higher exposure to staff. There has been general lack of training in radiation protection of doctors performing these procedures. Medical physicists are often asked to provide training or advice in such situations. International Commission on Radiological Protection (ICRP) has recently finalized a publication under the chairmanship of the presenter which is going to be published as Annals of ICRP 117. It deals with radiological protection aspects in vascular surgery, urology, orthopaedic surgery, obstetrics and gynaecology, gastroenterology, anaesthetics & pain management and sentinel lymph node biopsy. The IAEA has made available training materials as ppt slides on this subject that can be downloaded free and members of AAPM can effectively use. The IAEA has conducted training programs in which specialists from more than 35 countries have participated. The presentation shall review the work of ICRP and IAEA in this area in many countries.Learning Objectives:1. To understand radiation doses and risks to patients and staff in fluoroscopic guided procedures performed outside radiology such as in operation theatres2. To become familiar with recent international resources in this area3. To understand radiation protection methods as applicable in specific situation of procedures in operating theatres
WE‐B‐213CD‐02: NCRP‐168 as a Training and Operational Resource
Authors: Balter S 
Published: June 2012

NCRP Report 168 provides guidance on facilities as well as on patient and worker radiation safety during fluoroscopically guided interventions (FGI). Fluoroscopy is widely used in surgical settings in ways that can be comparable to its use in other FGI procedures. Surgical fluoroscopes range from simple mobile analog C‐arms, heavy mobiles with most of characteristics of a fixed system, to state of the art fixed systems. Patient and worker radiation safety concerns along with training, credentialing, and privileging of surgical staff are similar to those for all other FGI procedures. Recommendations relevant to the surgical setting will be reviewed. Two key recommendations are: An FGI procedure shall be performed or supervised only by a physician or other medical professional with fluoroscopic and clinical privileges appropriate to the specific procedure. An FGI procedure shall be performed or supervised only by a physician or other medical professional with fluoroscopic and clinical privileges appropriate to the specific procedure. Other topics such as responsibilities of all workers for their own radiation protection, those of the attending surgeon for patient dose management and follow‐up, and those of the facility for providing necessary resources will also be briefly discussed.Learning Objectives:1. To understand the responsibilities of surgeons and others working in a FGI environment toward patient and worker radiation safety.2. To understand radiation protection requirements and actions necessary for personal safety while radiation is in use in a surgical environment3. To gain familiarity with the knowledge base needed to safely perform or supervise FGA procedures in the surgical environment.
TH‐A‐211‐01: Deformable Registration in the Clinic: From Commissioning to Advanced Applications
Authors: Schreibmann E 
Published: June 2012

With deformable registration presented by several companies as a tool to improve treatment accuracy, clinical users often question the advantages and disadvantages of adopting this sophisticated technology to daily practice. This course will detail our experience in using deformable registration in the clinic. It will cover topics such as commissioning a system of deformable registration, patient‐specific QA to identify errors in the displacement field, common applications, anticipated changes in the clinical workflow and subsequent time savings. Emphasis will be placed on explaining the technology's mathematics and applications in layman terms to illustrate how various parameters can be chosen to fit various applications or can produce significant errors if improperly selected.Learning Objectives:1. Detail the installation and commissioning2. Present how parameter selection influence results3. Show clinical examples and practical conclusions drawn from the daily use of deformable registration.
TH‐A‐BRB‐03: Tumor Control Probability Models for Hypofractionated Therapy: Known Unknowns, Unknown Unknowns, and Comparison with Data
Authors: Deasy J , Jeong J 
Published: June 2012

In order to better understand factors that affect tumor dose response to hypofractionated and standard fractionation (∼ 2 Gy/day), we recently constructed a state‐based model to predict radiotherapy tumor outcomes. Put simply the model assumes that each small volume of the tumor at the beginning of therapy (a ‘tumorlet’) has a given, unchanging, supply level of oxygen and glucose. Cells are divided into those that have both adequate oxygen and adequate glucose (and are therefore at least intermittently proliferating), cells that only have adequate glucose (radiobiologically hypoxic but surviving), and those that are dying due to a lack of oxygen and glucose. The model is just complicated enough to take into account measured cell loss factors, growth fractions, and radiosensitivity as a function of cell cycle. The model naturally reproduces the effects of reoxygenation, accelerated clonogen proliferation, and regression as a function of the local tumorlet cell‐loss factor and growth fraction. Although the model appears to reproduce behavior consistent with response to standard fractionation, it does not adequately explain response to single‐ or few‐fraction delivery, where hypoxic cell survival is predicted to be orders‐ of‐magnitude too high. It is unlikely that a too‐high value of alpha/beta by itself explains the discrepancy as the ratio is expected to increase under hypoxic conditions by a factor equal to the oxygen enhancement ratio. These results are in agreement with previously published calculations by Brown et al. (IJROBP (2010) 78: 323‐327) using a different model of tumor response. We will discuss uncertainties in the model, including effects that have been left out, such as variations in vascular delivery.Learning Objectives:1. Understanding factors expected to impact radiotherapy response, including radiosensitivity, repair, reoxygenation, the cell loss factor, the growth fraction, and hypoxia.2. Understand basic mathematical formulations that can capture radiosensitivity and repair.
TH‐A‐BRB‐04: Vascular Response to Microbeam Radiation Therapy in Vivo Using a Murine Window Chamber Tumor Model
Authors: Dewhirst M , Fontanella A , Palmer G , Boss M , Zhang J , Hadsell M , Chang S 
Published: June 2012

Microbeam Radiation Therapy (MRT) has shown a marked tumor‐specific effect. The tissue‐sparing property of this unique treatment is possibly facilitated by efficient normal‐vessel repair mechanisms, contrary to the catastrophic disruption of poorly regulated tumor‐associated vasculature. However, significant controversy exists with regard to the role of endothelial cell death in radiation response. It is possible that the direct killing of tumor vasculature may increase radiation response within the tumor due to either oxygen/nutrient deprivation or through the “bystander effect”. The aim of this study was to characterize the vascular response to MRT in vivo using a murine window chamber model over an extended time course. MRT treatment at various doses (300 micron single beam, 0Gy, 50Gy, 80Gy) was applied to the murine window chamber tumor model. Changes in tumor‐associated vasculature after the MRT treatment utilizing intravital microscopy were profound. A robust angiogenic response was clearly present along the microbeam track in what appeared to be clusters of vessel proliferation following MRT of 50 and 80Gy. This distinctive pattern of angiogenesis was imaged through Day 7, as the irradiated track and regional microenvironment were infiltrated with a dense vascular network. In more recent experiments, we have observed infiltration of tumor cells along pre‐existing vascular networks adjacent to the microbeam, to distant unirradiated sites. These types of responses were not seen in controls or in chambers following wide beam irradiation to the entire window at comparable doses. This behavior strongly suggests that the treatment is promoting epithelial mesenchymal transition, angiogenesis and local invasion. Although these observations are for microbeam treatments, the biology being observed could equally be applied to the issue of marginal miss, which is of concern for high dose conformal radiotherapy. The window chamber model provides a novel approach to direct visualization of the longitudinal vascular changes following treatment with MRT. These findings suggest that radiation induced angiogenesis at sites adjacent to the MRT beam may play an important role in modifying the tumor microenvironment. Such a response may have significant implications with regard to the understood mechanism of radiation‐induced cell death.Learning Objectives:1. Be able to describe concept of microbeam irradiation2. Understand underlying mechanisms and implications of driving angiogenic response of tumor after irradiationThis work was supported by NIH/NCI grant CA40355 and DoD grant BC083195.
TH‐B‐211‐01: Cone Beam CT: Dose Measurement, Calculation, and Inclusion in the Treatment Plan
Authors: Alaei P , Ding G 
Published: June 2012

Measurement and calculation of the dose from imaging beams have gained interest following development of cone beam CT (CBCT) systems. Much work has been done in the use of various dosimeters to measure, as well as methods and algorithms to calculate the imaging dose both in phantom and in patient. Depending on beam quality, measuring imaging dose produces its own challenges. There have also been proposals on the methodology and quantities suitable to describe the dose from CBCT as well as those suitable to quantify the dose to patient. This lecture will review the various measurement and calculation methods as well as quantities used to describe the dose from CBCT systems. It will also review methods being developed to include imaging dose in the patient treatment plans.Learning Objectives:1. Understand the dosimeteric tools and methods used to measure dose from CBCT imaging2. Understand the methods used to calculate dose from CBCT imaging3. Understand the methodology used to describe the dose from CBCT imaging4. Understand the methods used to generate beam data from imaging systems for commissioning imaging beams in the treatment planning systems5. Update on the progress made on inclusion of the CBCT imaging dose in patient treatment plans using existing commercial planning systems as well as development of new algorithms.