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Sample records for radiation therapy optimization

  1. Two Effective Heuristics for Beam Angle Optimization in Radiation Therapy

    CERN Document Server

    Yarmand, Hamed

    2013-01-01

    In radiation therapy, mathematical methods have been used for optimizing treatment planning for delivery of sufficient dose to the cancerous cells while keeping the dose to critical surrounding structures minimal. This optimization problem can be modeled using mixed integer programming (MIP) whose solution gives the optimal beam orientation as well as optimal beam intensity. The challenge, however, is the computation time for this large scale MIP. We propose and investigate two novel heuristic approaches to reduce the computation time considerably while attaining high-quality solutions. We introduce a family of heuristic cuts based on the concept of 'adjacent beams' and a beam elimination scheme based on the contribution of each beam to deliver the dose to the tumor in the ideal plan in which all potential beams can be used simultaneously. We show the effectiveness of these heuristics for intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) on a clinical liver case.

  2. Optimization of adaptive radiation therapy in cervical cancer: Solutions for photon and proton therapy

    NARCIS (Netherlands)

    van de Schoot, A.J.A.J.

    2016-01-01

    In cervical cancer radiation therapy, an adaptive strategy is required to compensate for interfraction anatomical variations in order to achieve adequate dose delivery. In this thesis, we have aimed at optimizing adaptive radiation therapy in cervical cancer to improve treatment efficiency and

  3. Optimization in Radiation Therapy: Applications in Brachytherapy and Intensity Modulated Radiation Therapy

    Science.gov (United States)

    McGeachy, Philip David

    Over 50% of cancer patients require radiation therapy (RT). RT is an optimization problem requiring maximization of the radiation damage to the tumor while minimizing the harm to the healthy tissues. This dissertation focuses on two main RT optimization problems: 1) brachytherapy and 2) intensity modulated radiation therapy (IMRT). The brachytherapy research involved solving a non-convex optimization problem by creating an open-source genetic algorithm optimizer to determine the optimal radioactive seed distribution for a given set of patient volumes and constraints, both dosimetric- and implant-based. The optimizer was tested for a set of 45 prostate brachytherapy patients. While all solutions met the clinical standards, they also benchmarked favorably with those generated by a standard commercial solver. Compared to its compatriot, the salient features of the generated solutions were: slightly reduced prostate coverage, lower dose to the urethra and rectum, and a smaller number of needles required for an implant. Historically, IMRT requires modulation of fluence while keeping the photon beam energy fixed. The IMRT-related investigation in this thesis aimed at broadening the solution space by varying photon energy. The problem therefore involved simultaneous optimization of photon beamlet energy and fluence, denoted by XMRT. Formulating the problem as convex, linear programming was applied to obtain solutions for optimal energy-dependent fluences, while achieving all clinical objectives and constraints imposed. Dosimetric advantages of XMRT over single-energy IMRT in the improved sparing of organs at risk (OARs) was demonstrated in simplified phantom studies. The XMRT algorithm was improved to include clinical dose-volume constraints and clinical studies for prostate and head and neck cancer patients were investigated. Compared to IMRT, XMRT provided improved dosimetric benefit in the prostate case, particularly within intermediate- to low-dose regions (≤ 40 Gy

  4. Projections onto the Pareto surface in multicriteria radiation therapy optimization.

    Science.gov (United States)

    Bokrantz, Rasmus; Miettinen, Kaisa

    2015-10-01

    To eliminate or reduce the error to Pareto optimality that arises in Pareto surface navigation when the Pareto surface is approximated by a small number of plans. The authors propose to project the navigated plan onto the Pareto surface as a postprocessing step to the navigation. The projection attempts to find a Pareto optimal plan that is at least as good as or better than the initial navigated plan with respect to all objective functions. An augmented form of projection is also suggested where dose-volume histogram constraints are used to prevent that the projection causes a violation of some clinical goal. The projections were evaluated with respect to planning for intensity modulated radiation therapy delivered by step-and-shoot and sliding window and spot-scanned intensity modulated proton therapy. Retrospective plans were generated for a prostate and a head and neck case. The projections led to improved dose conformity and better sparing of organs at risk (OARs) for all three delivery techniques and both patient cases. The mean dose to OARs decreased by 3.1 Gy on average for the unconstrained form of the projection and by 2.0 Gy on average when dose-volume histogram constraints were used. No consistent improvements in target homogeneity were observed. There are situations when Pareto navigation leaves room for improvement in OAR sparing and dose conformity, for example, if the approximation of the Pareto surface is coarse or the problem formulation has too permissive constraints. A projection onto the Pareto surface can identify an inaccurate Pareto surface representation and, if necessary, improve the quality of the navigated plan.

  5. The Advantages of Collimator Optimization for Intensity Modulated Radiation Therapy

    Science.gov (United States)

    Doozan, Brian

    The goal of this study was to improve dosimetry for pelvic, lung, head and neck, and other cancers sites with aspherical planning target volumes (PTV) using a new algorithm for collimator optimization for intensity modulated radiation therapy (IMRT) that minimizes the x-jaw gap (CAX) and the area of the jaws (CAA) for each treatment field. A retroactive study on the effects of collimator optimization of 20 patients was performed by comparing metric results for new collimator optimization techniques in Eclipse version 11.0. Keeping all other parameters equal, multiple plans are created using four collimator techniques: CA 0, all fields have collimators set to 0°, CAE, using the Eclipse collimator optimization, CAA, minimizing the area of the jaws around the PTV, and CAX, minimizing the x-jaw gap. The minimum area and the minimum x-jaw angles are found by evaluating each field beam's eye view of the PTV with ImageJ and finding the desired parameters with a custom script. The evaluation of the plans included the monitor units (MU), the maximum dose of the plan, the maximum dose to organs at risk (OAR), the conformity index (CI) and the number of fields that are calculated to split. Compared to the CA0 plans, the monitor units decreased on average by 6% for the CAX method with a p-value of 0.01 from an ANOVA test. The average maximum dose remained within 1.1% difference between all four methods with the lowest given by CAX. The maximum dose to the most at risk organ was best spared by the CAA method, which decreased by 0.62% compared to the CA0. Minimizing the x-jaws significantly reduced the number of split fields from 61 to 37. In every metric tested the CAX optimization produced comparable or superior results compared to the other three techniques. For aspherical PTVs, CAX on average reduced the number of split fields, lowered the maximum dose, minimized the dose to the surrounding OAR, and decreased the monitor units. This is achieved while maintaining the same

  6. Optimizing global liver function in radiation therapy treatment planning.

    Science.gov (United States)

    Wu, Victor W; Epelman, Marina A; Wang, Hesheng; Edwin Romeijn, H; Feng, Mary; Cao, Yue; Ten Haken, Randall K; Matuszak, Martha M

    2016-09-07

    Liver stereotactic body radiation therapy (SBRT) patients differ in both pre-treatment liver function (e.g. due to degree of cirrhosis and/or prior treatment) and radiosensitivity, leading to high variability in potential liver toxicity with similar doses. This work investigates three treatment planning optimization models that minimize risk of toxicity: two consider both voxel-based pre-treatment liver function and local-function-based radiosensitivity with dose; one considers only dose. Each model optimizes different objective functions (varying in complexity of capturing the influence of dose on liver function) subject to the same dose constraints and are tested on 2D synthesized and 3D clinical cases. The normal-liver-based objective functions are the linearized equivalent uniform dose ([Formula: see text]) (conventional '[Formula: see text] model'), the so-called perfusion-weighted [Formula: see text] ([Formula: see text]) (proposed 'fEUD model'), and post-treatment global liver function (GLF) (proposed 'GLF model'), predicted by a new liver-perfusion-based dose-response model. The resulting [Formula: see text], fEUD, and GLF plans delivering the same target [Formula: see text] are compared with respect to their post-treatment function and various dose-based metrics. Voxel-based portal venous liver perfusion, used as a measure of local function, is computed using DCE-MRI. In cases used in our experiments, the GLF plan preserves up to [Formula: see text] more liver function than the fEUD ([Formula: see text]) plan does in 2D cases, and up to [Formula: see text] in 3D cases. The GLF and fEUD plans worsen in [Formula: see text] of functional liver on average by 1.0 Gy and 0.5 Gy in 2D and 3D cases, respectively. Liver perfusion information can be used during treatment planning to minimize the risk of toxicity by improving expected GLF; the degree of benefit varies with perfusion pattern. Although fEUD model optimization is computationally inexpensive and often

  7. Brachytherapy optimal planning with application to intravascular radiation therapy.

    Science.gov (United States)

    Sadegh, P; Mourtada, F A; Taylor, R H; Anderson, J H

    1999-09-01

    We have been studying brachytherapy planning with the objective of minimizing the maximum deviation of the delivered dose from prescribed dose bounds for treatment volumes. A general framework for optimal treatment planning is presented and the minmax optimization is formulated as a linear program. Dose rate calculations are based on the dosimetry formulation of the American Association of Physicists in Medicine, Task Group 43. We apply the technique to optimal planning for intravascular brachytherapy of intimal hyperplasia using ultrasound data and 192Ir seeds. The planning includes determination of an optimal dwell-time sequence for a train of seeds that deliver radiation while stepping through the vessel lesion. The results illustrate the advantage of this strategy over the common approach of delivering radiation by positioning a single train of seeds along the whole lesion.

  8. Radiation Therapy

    Science.gov (United States)

    ... Be extra careful not to spend time with children or pregnant women. Internal Radiation Therapy Makes You Give Off Radiation With systemic radiation, your body fluids ( urine , sweat, and saliva ) will give off radiation for a while. With ...

  9. Radiation Therapy

    Science.gov (United States)

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

  10. Computational Modeling of Medical Images of Brain Tumor Patients for Optimized Radiation Therapy Planning

    DEFF Research Database (Denmark)

    Agn, Mikael

    In brain tumor radiation therapy, the aim is to maximize the delivered radiation dose to the targeted tumor and at the same time minimize the dose to sensitive healthy structures – so-called organs-at-risk (OARs). When planning a radiation therapy session, the tumor and the OARs therefore need...... to be delineated on medical images of the patient’s head, to be able to optimize a radiation dose plan. In clinical practice, the delineation is performed manually with limited assistance from automatic procedures, which is both time-consuming and typically suffers from poor reproducibility. There is, therefore...

  11. Particle swarm optimizer for weighting factor selection in intensity-modulated radiation therapy optimization algorithms.

    Science.gov (United States)

    Yang, Jie; Zhang, Pengcheng; Zhang, Liyuan; Shu, Huazhong; Li, Baosheng; Gui, Zhiguo

    2017-01-01

    In inverse treatment planning of intensity-modulated radiation therapy (IMRT), the objective function is typically the sum of the weighted sub-scores, where the weights indicate the importance of the sub-scores. To obtain a high-quality treatment plan, the planner manually adjusts the objective weights using a trial-and-error procedure until an acceptable plan is reached. In this work, a new particle swarm optimization (PSO) method which can adjust the weighting factors automatically was investigated to overcome the requirement of manual adjustment, thereby reducing the workload of the human planner and contributing to the development of a fully automated planning process. The proposed optimization method consists of three steps. (i) First, a swarm of weighting factors (i.e., particles) is initialized randomly in the search space, where each particle corresponds to a global objective function. (ii) Then, a plan optimization solver is employed to obtain the optimal solution for each particle, and the values of the evaluation functions used to determine the particle's location and the population global location for the PSO are calculated based on these results. (iii) Next, the weighting factors are updated based on the particle's location and the population global location. Step (ii) is performed alternately with step (iii) until the termination condition is reached. In this method, the evaluation function is a combination of several key points on the dose volume histograms. Furthermore, a perturbation strategy - the crossover and mutation operator hybrid approach - is employed to enhance the population diversity, and two arguments are applied to the evaluation function to improve the flexibility of the algorithm. In this study, the proposed method was used to develop IMRT treatment plans involving five unequally spaced 6MV photon beams for 10 prostate cancer cases. The proposed optimization algorithm yielded high-quality plans for all of the cases, without human

  12. RT-13OPTIMIZING RADIATION THERAPY FOR GLIOBLASTOMA PATIENTS: A COMPARATIVE STUDY OF USING DIFFERENT MRI MODALITIES TO MINIMIZE RADIATION INJURY

    Science.gov (United States)

    Kim, Arin; Lee, Albert Weilin; Lee, Anna; Yanagihara, Theodore; Jani, Ashish; Isaacson, Steven R.; Cheng, Simon K.; Bruce, Jeffrey N.; Sisti, Michael B.; McKhann, Guy M.; Iwamoto, Fabio; Lassman, Andrew; Wang, Tony J.C.

    2014-01-01

    Glioblastoma multiforme is the most common and lethal primary malignant brain tumor and radiation therapy is considered the standard of care in the adjuvant setting. Current radiation treatment planning guidelines recommend FLAIR MRI sequence with a 2 cm margin to encompass the subclinical tumor spread. However, the FLAIR modality extensively visualizes the surrounding edema, possibly leading to unnecessary radiation toxicity to healthy brain tissue. We hypothesize that we can optimize radiation therapy by using alternative MRI modalities or by decreasing clinical tumor volume margins to minimize toxicity without compromising accurate tumor targeting. We retrospectively collected data for 21 patients with pathology confirmed recurrence and created radiation treatment plans using ADC, ADC without FLAIR shine-through (ADCst), DWI, T1, and FLAIR. For the FLAIR both a 1 cm and 2 cm margin was used (FLAIR1 and FLAIR2). Boolean operators were used to calculate the accuracy of targeting tumor recurrence and excessive radiation volume compared to the standard FLAIR2 treatment plan. All MRI modalities had complete coverage of the recurrent tumor and the mean differences in accuracy between the different MRI modalities and FLAIR2 was not significant. However, there was a significant reduction in the excessive radiation volume compared to FLAIR2. ADCst had a 51.3% reduction, DWI 42.3%, T1 42.6%, and FLAIR1 44.6% reduction of excessive radiation volume compared to FLAIR2 (p < 0.05). ADC did not have a significant reduction of excessive radiation volume compared to FLAIR2. Our data support the hypothesis that using MRI modalities other than the standard FLAIR or decreasing the margin by 1cm may optimize radiation therapy for GBM patients by reducing unnecessary radiation dose to healthy brain tissue without compromising accuracy. By using new MRI modalities in radiation treatment planning or modifying clinical tumor volume margins we can decrease radiation toxicity to patients

  13. Brachytherapy optimal planning with application to intravascular radiation therapy

    DEFF Research Database (Denmark)

    Sadegh, Payman; Mourtada, Firas A.; Taylor, Russell H.

    1999-01-01

    . Dose rate calculations are based on the sosimetry formulation of the American Association of Physicists in Medicine, Task Group 43. We apply the technique to optimal planning for intravascular brachytherapy of intimal hyperplasia using ultrasound data and 192Ir seeds. The planning includes...

  14. Beam angle optimization for intensity-modulated radiation therapy using a guided pattern search method

    Science.gov (United States)

    Rocha, Humberto; Dias, Joana M.; Ferreira, Brígida C.; Lopes, Maria C.

    2013-05-01

    Generally, the inverse planning of radiation therapy consists mainly of the fluence optimization. The beam angle optimization (BAO) in intensity-modulated radiation therapy (IMRT) consists of selecting appropriate radiation incidence directions and may influence the quality of the IMRT plans, both to enhance better organ sparing and to improve tumor coverage. However, in clinical practice, most of the time, beam directions continue to be manually selected by the treatment planner without objective and rigorous criteria. The goal of this paper is to introduce a novel approach that uses beam’s-eye-view dose ray tracing metrics within a pattern search method framework in the optimization of the highly non-convex BAO problem. Pattern search methods are derivative-free optimization methods that require a few function evaluations to progress and converge and have the ability to better avoid local entrapment. The pattern search method framework is composed of a search step and a poll step at each iteration. The poll step performs a local search in a mesh neighborhood and ensures the convergence to a local minimizer or stationary point. The search step provides the flexibility for a global search since it allows searches away from the neighborhood of the current iterate. Beam’s-eye-view dose metrics assign a score to each radiation beam direction and can be used within the pattern search framework furnishing a priori knowledge of the problem so that directions with larger dosimetric scores are tested first. A set of clinical cases of head-and-neck tumors treated at the Portuguese Institute of Oncology of Coimbra is used to discuss the potential of this approach in the optimization of the BAO problem.

  15. Radiation Therapy (For Parents)

    Science.gov (United States)

    ... Giving Teens a Voice in Health Care Decisions Radiation Therapy KidsHealth > For Parents > Radiation Therapy Print A ... have many questions and concerns about it. About Radiation Therapy In radiation therapy, high-energy radiation from ...

  16. Direct-aperture optimization applied to selection of beam orientations in intensity-modulated radiation therapy

    Science.gov (United States)

    Bedford, J. L.; Webb, S.

    2007-01-01

    Direct-aperture optimization (DAO) was applied to iterative beam-orientation selection in intensity-modulated radiation therapy (IMRT), so as to ensure a realistic segmental treatment plan at each iteration. Nested optimization engines dealt separately with gantry angles, couch angles, collimator angles, segment shapes, segment weights and wedge angles. Each optimization engine performed a random search with successively narrowing step sizes. For optimization of segment shapes, the filtered backprojection (FBP) method was first used to determine desired fluence, the fluence map was segmented, and then constrained direct-aperture optimization was used thereafter. Segment shapes were fully optimized when a beam angle was perturbed, and minimally re-optimized otherwise. The algorithm was compared with a previously reported method using FBP alone at each orientation iteration. An example case consisting of a cylindrical phantom with a hemi-annular planning target volume (PTV) showed that for three-field plans, the method performed better than when using FBP alone, but for five or more fields, neither method provided much benefit over equally spaced beams. For a prostate case, improved bladder sparing was achieved through the use of the new algorithm. A plan for partial scalp treatment showed slightly improved PTV coverage and lower irradiated volume of brain with the new method compared to FBP alone. It is concluded that, although the method is computationally intensive and not suitable for searching large unconstrained regions of beam space, it can be used effectively in conjunction with prior class solutions to provide individually optimized IMRT treatment plans.

  17. Radiation Therapy: Professions in Radiation Therapy

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Professions in Radiation Therapy Radiation Oncologist Therapeutic Medical Physicist Radiation Therapist Dosimetrist Radiation Oncology Nurse Social Worker Dietitian Radiation Oncologist Radiation oncologists are physicians who oversee the ...

  18. SU-E-T-295: Simultaneous Beam Sampling and Aperture Shape Optimization for Station Parameter Optimized Radiation Therapy (SPORT)

    Energy Technology Data Exchange (ETDEWEB)

    Zarepisheh, M; Li, R; Xing, L [Stanford UniversitySchool of Medicine, Stanford, CA (United States); Ye, Y [Stanford Univ, Management Science and Engineering, Stanford, Ca (United States); Boyd, S [Stanford University, Electrical Engineering, Stanford, CA (United States)

    2014-06-01

    Purpose: Station Parameter Optimized Radiation Therapy (SPORT) was recently proposed to fully utilize the technical capability of emerging digital LINACs, in which the station parameters of a delivery system, (such as aperture shape and weight, couch position/angle, gantry/collimator angle) are optimized altogether. SPORT promises to deliver unprecedented radiation dose distributions efficiently, yet there does not exist any optimization algorithm to implement it. The purpose of this work is to propose an optimization algorithm to simultaneously optimize the beam sampling and aperture shapes. Methods: We build a mathematical model whose variables are beam angles (including non-coplanar and/or even nonisocentric beams) and aperture shapes. To solve the resulting large scale optimization problem, we devise an exact, convergent and fast optimization algorithm by integrating three advanced optimization techniques named column generation, gradient method, and pattern search. Column generation is used to find a good set of aperture shapes as an initial solution by adding apertures sequentially. Then we apply the gradient method to iteratively improve the current solution by reshaping the aperture shapes and updating the beam angles toward the gradient. Algorithm continues by pattern search method to explore the part of the search space that cannot be reached by the gradient method. Results: The proposed technique is applied to a series of patient cases and significantly improves the plan quality. In a head-and-neck case, for example, the left parotid gland mean-dose, brainstem max-dose, spinal cord max-dose, and mandible mean-dose are reduced by 10%, 7%, 24% and 12% respectively, compared to the conventional VMAT plan while maintaining the same PTV coverage. Conclusion: Combined use of column generation, gradient search and pattern search algorithms provide an effective way to optimize simultaneously the large collection of station parameters and significantly improves

  19. Spherical cluster analysis for beam angle optimization in intensity-modulated radiation therapy treatment planning

    Science.gov (United States)

    Bangert, Mark; Oelfke, Uwe

    2010-10-01

    An intuitive heuristic to establish beam configurations for intensity-modulated radiation therapy is introduced as an extension of beam ensemble selection strategies applying scalar scoring functions. It is validated by treatment plan comparisons for three intra-cranial, pancreas, and prostate cases each. Based on a patient specific matrix listing the radiological quality of candidate beam directions individually for every target voxel, a set of locally ideal beam angles is generated. The spherical distribution of locally ideal beam angles is characteristic for every treatment site and patient: ideal beam angles typically cluster around distinct orientations. We interpret the cluster centroids, which are identified with a spherical K-means algorithm, as irradiation angles of an intensity-modulated radiation therapy treatment plan. The fluence profiles are subsequently optimized during a conventional inverse planning process. The average computation time for the pre-optimization of a beam ensemble is six minutes on a state-of-the-art work station. The treatment planning study demonstrates the potential benefit of the proposed beam angle optimization strategy. For the three prostate cases under investigation, the standard treatment plans applying nine coplanar equi-spaced beams and treatment plans applying an optimized non-coplanar nine-beam ensemble yield clinically comparable dose distributions. For symmetric patient geometries, the dose distribution formed by nine equi-spaced coplanar beams cannot be improved significantly. For the three pancreas and intra-cranial cases under investigation, the optimized non-coplanar beam ensembles enable better sparing of organs at risk while guaranteeing equivalent target coverage. Beam angle optimization by spherical cluster analysis shows the biggest impact for target volumes located asymmetrically within the patient and close to organs at risk.

  20. Spherical cluster analysis for beam angle optimization in intensity-modulated radiation therapy treatment planning.

    Science.gov (United States)

    Bangert, Mark; Oelfke, Uwe

    2010-10-07

    An intuitive heuristic to establish beam configurations for intensity-modulated radiation therapy is introduced as an extension of beam ensemble selection strategies applying scalar scoring functions. It is validated by treatment plan comparisons for three intra-cranial, pancreas, and prostate cases each. Based on a patient specific matrix listing the radiological quality of candidate beam directions individually for every target voxel, a set of locally ideal beam angles is generated. The spherical distribution of locally ideal beam angles is characteristic for every treatment site and patient: ideal beam angles typically cluster around distinct orientations. We interpret the cluster centroids, which are identified with a spherical K-means algorithm, as irradiation angles of an intensity-modulated radiation therapy treatment plan. The fluence profiles are subsequently optimized during a conventional inverse planning process. The average computation time for the pre-optimization of a beam ensemble is six minutes on a state-of-the-art work station. The treatment planning study demonstrates the potential benefit of the proposed beam angle optimization strategy. For the three prostate cases under investigation, the standard treatment plans applying nine coplanar equi-spaced beams and treatment plans applying an optimized non-coplanar nine-beam ensemble yield clinically comparable dose distributions. For symmetric patient geometries, the dose distribution formed by nine equi-spaced coplanar beams cannot be improved significantly. For the three pancreas and intra-cranial cases under investigation, the optimized non-coplanar beam ensembles enable better sparing of organs at risk while guaranteeing equivalent target coverage. Beam angle optimization by spherical cluster analysis shows the biggest impact for target volumes located asymmetrically within the patient and close to organs at risk.

  1. A nested partitions framework for beam angle optimization in intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    D' Souza, Warren D; Nazareth, Daryl P [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Zhang, Hao H; Shi Leyuan [Department of Industrial and Systems Engineering, University of Wisconsin, Madison, WI (United States); Meyer, Robert R [Computer Sciences Department, University of Wisconsin, Madison, WI (United States)], E-mail: dsouzaw@ohsu.edu

    2008-06-21

    Coupling beam angle optimization with dose optimization in intensity-modulated radiation therapy (IMRT) increases the size and complexity of an already large-scale combinatorial optimization problem. We have developed a novel algorithm, nested partitions (NP), that is capable of finding suitable beam angle sets by guiding the dose optimization process. NP is a metaheuristic that is flexible enough to guide the search of a heuristic or deterministic dose optimization algorithm. The NP method adaptively samples from the entire feasible region, or search space, and coordinates the sampling effort with a systematic partitioning of the feasible region at successive iterations, concentrating the search in promising subsets. We used a 'warm-start' approach by initiating NP with beam angle samples derived from an integer programming (IP) model. In this study, we describe our implementation of the NP framework with a commercial optimization algorithm. We compared the NP framework with equi-spaced beam angle selection, the IP method, greedy heuristic and random sampling heuristic methods. The results of the NP approach were evaluated using two clinical cases (head and neck and whole pelvis) involving the primary tumor and nodal volumes. Our results show that NP produces better quality solutions than the alternative considered methods.

  2. Clinical decision tool for optimal delivery of liver stereotactic body radiation therapy: Photons versus protons.

    Science.gov (United States)

    Gandhi, Saumil J; Liang, Xing; Ding, Xuanfeng; Zhu, Timothy C; Ben-Josef, Edgar; Plastaras, John P; Metz, James M; Both, Stefan; Apisarnthanarax, Smith

    2015-01-01

    Stereotactic body radiation therapy (SBRT) for treatment of liver tumors is often limited by liver dose constraints. Protons offer potential for more liver sparing, but clinical situations in which protons may be superior to photons are not well described. We developed and validated a treatment decision model to determine whether liver tumors of certain sizes and locations are more suited for photon versus proton SBRT. Six spherical mock tumors from 1 to 6 cm in diameter were contoured on computed tomography images of 1 patient at 4 locations: dome, caudal, left medial, and central. Photon and proton plans were generated to deliver 50 Gy in 5 fractions to each tumor and optimized to deliver equivalent target coverage and maximal liver sparing. Using these plans, we developed a hypothesis-generating model to predict the optimal modality for maximal liver sparing based on tumor size and location. We then validated this model in 10 patients with liver tumors. Protons spared significantly more liver than photons for dome or central tumors ≥3 cm (dome: 134 ± 21 cm(3), P = .03; central: 108 ± 4 cm(3), P = .01). Our model correctly predicted the optimal SBRT modality for all 10 patients. For patients with dome or central tumors ≥3 cm, protons significantly increased the volume of liver spared (176 ± 21 cm(3), P = .01) and decreased the mean liver dose (8.4 vs 12.2 Gy, P = .01) while offering no significant advantage for tumors protons should be considered as the radiation modality of choice for dome and central tumors >3 cm to allow maximal liver sparing and potentially reduce radiation toxicity. Protons should also be considered for any tumor >5 cm if photon plans fail to achieve adequate coverage or exceed the mean liver threshold. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  3. Comparison of optimization algorithms in intensity-modulated radiation therapy planning

    Science.gov (United States)

    Kendrick, Rachel

    Intensity-modulated radiation therapy is used to better conform the radiation dose to the target, which includes avoiding healthy tissue. Planning programs employ optimization methods to search for the best fluence of each photon beam, and therefore to create the best treatment plan. The Computational Environment for Radiotherapy Research (CERR), a program written in MATLAB, was used to examine some commonly-used algorithms for one 5-beam plan. Algorithms include the genetic algorithm, quadratic programming, pattern search, constrained nonlinear optimization, simulated annealing, the optimization method used in Varian EclipseTM, and some hybrids of these. Quadratic programing, simulated annealing, and a quadratic/simulated annealing hybrid were also separately compared using different prescription doses. The results of each dose-volume histogram as well as the visual dose color wash were used to compare the plans. CERR's built-in quadratic programming provided the best overall plan, but avoidance of the organ-at-risk was rivaled by other programs. Hybrids of quadratic programming with some of these algorithms seems to suggest the possibility of better planning programs, as shown by the improved quadratic/simulated annealing plan when compared to the simulated annealing algorithm alone. Further experimentation will be done to improve cost functions and computational time.

  4. SU-F-T-209: Multicriteria Optimization Algorithm for Intensity Modulated Radiation Therapy Using Pencil Proton Beam Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, C; Kamal, H [Mayo Clinic, Rochester, MN (United States)

    2016-06-15

    Purpose: To provide a multicriteria optimization algorithm for intensity modulated radiation therapy using pencil proton beam scanning. Methods: Intensity modulated radiation therapy using pencil proton beam scanning requires efficient optimization algorithms to overcome the uncertainties in the Bragg peaks locations. This work is focused on optimization algorithms that are based on Monte Carlo simulation of the treatment planning and use the weights and the dose volume histogram (DVH) control points to steer toward desired plans. The proton beam treatment planning process based on single objective optimization (representing a weighted sum of multiple objectives) usually leads to time-consuming iterations involving treatment planning team members. We proved a time efficient multicriteria optimization algorithm that is developed to run on NVIDIA GPU (Graphical Processing Units) cluster. The multicriteria optimization algorithm running time benefits from up-sampling of the CT voxel size of the calculations without loss of fidelity. Results: We will present preliminary results of Multicriteria optimization for intensity modulated proton therapy based on DVH control points. The results will show optimization results of a phantom case and a brain tumor case. Conclusion: The multicriteria optimization of the intensity modulated radiation therapy using pencil proton beam scanning provides a novel tool for treatment planning. Work support by a grant from Varian Inc.

  5. Multi-GPU configuration of 4D intensity modulated radiation therapy inverse planning using global optimization

    Science.gov (United States)

    Hagan, Aaron; Sawant, Amit; Folkerts, Michael; Modiri, Arezoo

    2018-01-01

    We report on the design, implementation and characterization of a multi-graphic processing unit (GPU) computational platform for higher-order optimization in radiotherapy treatment planning. In collaboration with a commercial vendor (Varian Medical Systems, Palo Alto, CA), a research prototype GPU-enabled Eclipse (V13.6) workstation was configured. The hardware consisted of dual 8-core Xeon processors, 256 GB RAM and four NVIDIA Tesla K80 general purpose GPUs. We demonstrate the utility of this platform for large radiotherapy optimization problems through the development and characterization of a parallelized particle swarm optimization (PSO) four dimensional (4D) intensity modulated radiation therapy (IMRT) technique. The PSO engine was coupled to the Eclipse treatment planning system via a vendor-provided scripting interface. Specific challenges addressed in this implementation were (i) data management and (ii) non-uniform memory access (NUMA). For the former, we alternated between parameters over which the computation process was parallelized. For the latter, we reduced the amount of data required to be transferred over the NUMA bridge. The datasets examined in this study were approximately 300 GB in size, including 4D computed tomography images, anatomical structure contours and dose deposition matrices. For evaluation, we created a 4D-IMRT treatment plan for one lung cancer patient and analyzed computation speed while varying several parameters (number of respiratory phases, GPUs, PSO particles, and data matrix sizes). The optimized 4D-IMRT plan enhanced sparing of organs at risk by an average reduction of 26% in maximum dose, compared to the clinical optimized IMRT plan, where the internal target volume was used. We validated our computation time analyses in two additional cases. The computation speed in our implementation did not monotonically increase with the number of GPUs. The optimal number of GPUs (five, in our study) is directly related to the

  6. Improving the quality, efficiency and robustness of radiation therapy planning and delivery through mathematical optimization

    NARCIS (Netherlands)

    Balvert, Marleen

    2017-01-01

    Radiation therapy is an established cancer treatment which exploits ionizing radiation to harm tumourous cells. As radiation can pass through healthy tissue to reach the tumour, this treatment is particularly useful in the case of deep-seated tumours. However, it inevitably yields exposure of the

  7. GPU-based ultra-fast direct aperture optimization for online adaptive radiation therapy

    CERN Document Server

    Men, Chunhua; Jiang, Steve B

    2010-01-01

    Online adaptive radiation therapy (ART) has great promise to significantly reduce normal tissue toxicity and/or improve tumor control through real-time treatment adaptations based on the current patient anatomy. However, the major technical obstacle for clinical realization of online ART, namely the inability to achieve real-time efficiency in treatment re-planning, has yet to be solved. To overcome this challenge, this paper presents our work on the implementation of an intensity modulated radiation therapy (IMRT) direct aperture optimization (DAO) algorithm on graphics processing unit (GPU) based on our previous work on CPU. We formulate the DAO problem as a large-scale convex programming problem, and use an exact method called column generation approach to deal with its extremely large dimensionality on GPU. Five 9-field prostate and five 5-field head-and-neck IMRT clinical cases with 5\\times5 mm2 beamlet size and 2.5\\times2.5\\times2.5 mm3 voxel size were used to evaluate our algorithm on GPU. It takes onl...

  8. GPU-based ultra-fast direct aperture optimization for online adaptive radiation therapy.

    Science.gov (United States)

    Men, Chunhua; Jia, Xun; Jiang, Steve B

    2010-08-07

    Online adaptive radiation therapy (ART) has great promise to significantly reduce normal tissue toxicity and/or improve tumor control through real-time treatment adaptations based on the current patient anatomy. However, the major technical obstacle for clinical realization of online ART, namely the inability to achieve real-time efficiency in treatment re-planning, has yet to be solved. To overcome this challenge, this paper presents our work on the implementation of an intensity-modulated radiation therapy (IMRT) direct aperture optimization (DAO) algorithm on the graphics processing unit (GPU) based on our previous work on the CPU. We formulate the DAO problem as a large-scale convex programming problem, and use an exact method called the column generation approach to deal with its extremely large dimensionality on the GPU. Five 9-field prostate and five 5-field head-and-neck IMRT clinical cases with 5 x 5 mm(2) beamlet size and 2.5 x 2.5 x 2.5 mm(3) voxel size were tested to evaluate our algorithm on the GPU. It takes only 0.7-3.8 s for our implementation to generate high-quality treatment plans on an NVIDIA Tesla C1060 GPU card. Our work has therefore solved a major problem in developing ultra-fast (re-)planning technologies for online ART.

  9. Explicit and convex optimization of plan quality measures in intensity-modulated radiation therapy treatment planning

    CERN Document Server

    Engberg, Lovisa; Forsgren, Anders; Hårdemark, Björn

    2016-01-01

    Given the widespread agreement that doses-at-volume play important roles in quality assessment of radiation therapy treatment plans, planning objectives that correlate well with explicit dose-at-volume optimization are likely to correlate well with plan quality. In this study, planning objectives are formulated to explicitly either minimize or maximize convex approximations of dose-at-volume, namely, mean-tail-doses. This is in contrast to the conventionally used planning objectives, which are used to maximize clinical goal fulfilment by relating to deviations from dose-at-volume thresholds. Advantages of the proposed planning objectives are investigated through juxtaposition with conventional objectives in a computational study of two patient cases, each with three doses-at-volume to be minimized subject to PTV coverage. With proposed planning objectives, this is translated into minimizing three mean-tail-doses. Comparison with conventional objectives is carried out in the dose-at-volume domain and in the no...

  10. Optimizing Cone Beam Computed Tomography (CBCT) System for Image Guided Radiation Therapy

    Science.gov (United States)

    Park, Chun Joo

    Cone Beam Computed Tomography (CBCT) system is the most widely used imaging device in image guided radiation therapy (IGRT), where set of 3D volumetric image of patient can be reconstructed to identify and correct position setup errors prior to the radiation treatment. This CBCT system can significantly improve precision of on-line setup errors of patient position and tumor target localization prior to the treatment. However, there are still a number of issues that needs to be investigated with CBCT system such as 1) progressively increasing defective pixels in imaging detectors by its frequent usage, 2) hazardous radiation exposure to patients during the CBCT imaging, 3) degradation of image quality due to patients' respiratory motion when CBCT is acquired and 4) unknown knowledge of certain anatomical features such as liver, due to lack of soft-tissue contrast which makes tumor motion verification challenging. In this dissertation, we explore on optimizing the use of cone beam computed tomography (CBCT) system under such circumstances. We begin by introducing general concept of IGRT. We then present the development of automated defective pixel detection algorithm for X-ray imagers that is used for CBCT imaging using wavelet analysis. We next investigate on developing fast and efficient low-dose volumetric reconstruction techniques which includes 1) fast digital tomosynthesis reconstruction using general-purpose graphics processing unit (GPGPU) programming and 2) fast low-dose CBCT image reconstruction based on the Gradient-Projection-Barzilai-Borwein formulation (GP-BB). We further developed two efficient approaches that could reduce the degradation of CBCT images from respiratory motion. First, we propose reconstructing four dimensional (4D) CBCT and DTS using respiratory signal extracted from fiducial markers implanted in liver. Second, novel motion-map constrained image reconstruction (MCIR) is proposed that allows reconstruction of high quality and high phase

  11. Poster - Thur Eve - 65: Optimization of an automatic image contouring system for radiation therapy.

    Science.gov (United States)

    Hamilton, T; Nedialkov, N; Wierzbicki, M

    2012-07-01

    Intensity modulated radiation therapy (IMRT) is an advanced technique used to concentrate the prescribed dose in the tumour while minimizing exposure to healthy tissues. Success in IMRT is greatly dependent upon the localization of the target volume and normal tissue, thus accurate contouring is crucial. In this paper, we describe an automated atlas-based image contouring system and our approach for improving the system by performing a full-scale optimization of registration parameters using high-performance computing. To achieve this, we use manually pre-contoured CT images of ten head and neck patients. For any parameter set, each patient data is registered with the remaining patients. Accuracy of the resulting contours is determined automatically by comparing their overlap with manually defined targets using Dice's similarity coefficient (DSC). This allows us to compare all permutations of the image registration parameter sets and input data to investigate their impact on final contour accuracy. Investigating the parameter space required 27,000 image registrations and 216,000 DSC computations. To perform these registrations we introduced a large cluster of high-performance computers and developed a parallel testing harness. The metrics collected from the tests show a wide range of performance, indicating that parameter selection is crucial in our contouring system. By selecting an optimized parameter set, we increased the mean overlap of the automatically contoured regions of interest by 50% and reduced registration time by 50% compared to the original parameters. Our findings illustrate that full-scale optimization is an effective method for improving the performance of the automated image contouring system. © 2012 American Association of Physicists in Medicine.

  12. Collimator optimization for small animal radiation therapy at a micro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Manuela C. [Heidelberg Univ., Mannheim (Germany). Medical Radiation Physics/Radiation Protection; Heidelberg Univ., Mannheim (Germany). Dept. of Radiation Oncology; Glatting, Gerhard [Heidelberg Univ., Mannheim (Germany). Medical Radiation Physics/Radiation Protection; Giordano, Frank A.; Wenz, Frederik; Fleckenstein, Jens [Heidelberg Univ., Mannheim (Germany). Dept. of Radiation Oncology; Brockmann, Marc A. [Heidelberg Univ., Mannheim (Germany). Dept. of Neuroradiology; University Medical Center Mainz (Germany). Dept. of Neuroradiology

    2017-05-01

    In radiation therapy of small animals treatment depths range from a few millimetres to several centimetres. In order to spare surrounding organs at risk steep dose gradients are necessary. To minimize the treatment time, and therefore the strain to the animals, a high dose rate is required. A description how these parameters can be optimized through an appropriate choice of collimators with different source surface distances (SSD) as well as different materials and geometries is presented. An industrial micro-CT unit (Y.Fox, YXLON GmbH, Hamburg, Germany) was converted into a precision irradiator for small animals. Different collimators of either stainless steel (Fe) with cylindrical bores (SSD = 42 mm) or tungsten (W) with conical bores (SSD = 14 mm) were evaluated. The dosimetry of very small radiation fields presents a challenge and was performed with GafChromic EBT3 films (Ashland, Vayne, KY, USA) in a water phantom. The films were calibrated with an ionization chamber in the uncollimated field. Treatments were performed via a rotation of the objects with a fixed radiation source. As expected, the shorter SSD of the W-collimators resulted in a (4.5 ± 1.6)-fold increase of the dose rates compared to the corresponding Fe-collimators. The ratios of the dose rates at 1 mm and 10 mm depth in the water phantom was (2.6 ± 0.2) for the Fe- and (4.5 ± 0.1) for the W-collimators. For rotational treatments in a cylindrical plastic phantom maximum dose rates of up to 1.2 Gy/min for Fe- and 5.1 Gy/min for W-collimators were measured. Choosing the smallest possible SSD leads to a high dose rate and a high surface dose, which is of advantage for the treatment of superficial target volumes. For larger SSD the dose rate is lower and the depth dose curve is shallower. This leads to a reduction of the surface dose and is best suited for treatments of deeper seated target volumes. Divergent collimator bores have, due to the reduced scatter within the collimators, a steeper

  13. Radiation Therapy

    Science.gov (United States)

    ... therapy, including: Fatigue Hair loss Skin changes Swelling/edema Nausea Sexual effects (reduced desire) Blood clots Your ... American Brain Tumor Association 8550 W. Bryn Mawr Ave. Ste 550 Chicago, IL 60631 © 2014 American Brain ...

  14. Optimizing Radiation Therapy Quality Assurance in Clinical Trials: A TROG 08.03 RAVES Substudy

    Energy Technology Data Exchange (ETDEWEB)

    Trada, Yuvnik, E-mail: yuvnik@gmail.com [Calvary Mater Newcastle, Waratah, New South Wales (Australia); Kneebone, Andrew [Royal North Shore Hospital, St Lenoards, New South Wales (Australia); Paneghel, Andrea [Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Pearse, Maria [Auckland Hospital, Auckland (New Zealand); Sidhom, Mark [Liverpool Hospital, Liverpool, New South Wales (Australia); Tang, Colin [Sir Charles Gairdner Hospital, Nedlands, Western Australia (Australia); Wiltshire, Kirsty; Haworth, Annette [Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Fraser-Browne, Carol [Auckland Hospital, Auckland (New Zealand); Martin, Jarad [Calvary Mater Newcastle, Waratah, New South Wales (Australia)

    2015-12-01

    Purpose: To explore site- and clinician-level factors associated with protocol violations requiring real-time-review (RTR) resubmission in a multicenter clinical trial to help tailor future quality assurance (QA) protocols. Methods and Materials: RAVES (Radiation Therapy–Adjuvant vs Early Salvage) (Trans-Tasman Radiation Oncology Group 08.03) is a randomized trial comparing adjuvant with early salvage radiation therapy in men with positive surgical margins or pT3 disease after prostatectomy. Quality assurance in RAVES required each clinician and site to submit a credentialing dummy run (DR) and for each patient's radiation therapy plan to undergo external RTR before treatment. Prospectively defined major violations from trial protocol required remedy and resubmission. Site and clinician factors associated with RTR resubmission were examined using hierarchical modeling. Results: Data were collected from 171 consecutive patients, treated by 46 clinicians at 32 hospitals. There were 47 RTR resubmissions (27%) due to 65 major violations. The relative rate of resubmission decreased by 29% per year as the study progressed (odds ratio OR. 0.71, P=.02). The majority of resubmissions were due to contouring violations (39 of 65) and dosimetric violations (22 of 65). For each additional patient accrued, significant decreases in RTR resubmission were seen at both clinician level (OR 0.75, P=.02) and site level (OR 0.72, P=.01). The rate of resubmission due to dosimetric violations was only 1.6% after the first 5 patients. Use of IMRT was associated with lower rates of resubmission compared with 3-dimensional conformal radiation therapy (OR 0.38, P=.05). Conclusion: Several low- and high-risk factors that may assist with tailoring future clinical trial QA were identified. Because the real-time resubmission rate was largely independent of the credentialing exercise, some form of RTR QA is recommended. The greatest benefit from QA was derived early in trial activation

  15. Radiation Therapy for Cancer

    Science.gov (United States)

    ... is exposed to radiation. Whether IMRT leads to improved control of tumor growth and better survival compared ... treatments. Some patients may receive radiation therapy and chemotherapy at the same time. The timing of radiation ...

  16. Hendee's radiation therapy physics

    CERN Document Server

    Pawlicki, Todd; Starkschall, George

    2016-01-01

    The publication of this fourth edition, more than ten years on from the publication of Radiation Therapy Physics third edition, provides a comprehensive and valuable update to the educational offerings in this field. Led by a new team of highly esteemed authors, building on Dr Hendee’s tradition, Hendee’s Radiation Therapy Physics offers a succinctly written, fully modernised update. Radiation physics has undergone many changes in the past ten years: intensity-modulated radiation therapy (IMRT) has become a routine method of radiation treatment delivery, digital imaging has replaced film-screen imaging for localization and verification, image-guided radiation therapy (IGRT) is frequently used, in many centers proton therapy has become a viable mode of radiation therapy, new approaches have been introduced to radiation therapy quality assurance and safety that focus more on process analysis rather than specific performance testing, and the explosion in patient-and machine-related data has necessitated an ...

  17. SU-E-T-589: Optimization of Patient Head Angle Position to Spare Hippocampus During the Brain Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, G; Kang, Y [Radiation Oncology, Seoul St. Mary’s Hospital, Seoul (Korea, Republic of); Kang, S; Kim, T; Kim, D; Suh, T [The Catholic University of Korea, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: Hippocampus is one of the important organs which controls emotions, behaviors, movements the memorizing and learning ability. In the conventional head & neck therapy position, it is difficult to perform the hippocampal-sparing brain radiation therapy. The purpose of this study is to investigate optimal head angle which can save the hippocampal-sparing and organ at risk (OAR) in conformal radiation therapy (CRT), Intensity modulation radiation therapy (IMRT) and helical tomotherapy (HT). Methods: Three types of radiation treatment plans, CRT, IMRT and Tomotherapy plans, were performed for 10 brain tumor patients. The image fusion between CT and MRI data were used in the contour due to the limited delineation of the target and OAR in the CT scan. The optimal condition plan was determined by comparing the dosimetric performance of the each plan with the use of various parameters which include three different techniques (CRT, IMRT, HT) and 4 angle (0, 15, 30, 40 degree). The each treatment plans of three different techniques were compared with the following parameters: conformity index (CI), homogeneity index (HI), target coverage, dose in the OARs, monitor units (MU), beam on time and the normal tissue complication probability (NTCP). Results: HI, CI and target coverage was most excellent in head angle 30 degree among all angle. When compared by modality, target coverage and CI showed good results in IMRT and TOMO than compared to the CRT. HI at the head angle 0 degrees is 1.137±0.17 (CRT), 1.085±0.09 (IMRT) and 1.077±0.06 (HT). HI at the head angle 30 degrees is 1.056±0.08 (CRT), 1.020±0.05 (IMRT) and 1.022±0.07 (HT). Conclusion: The results of our study show that when head angle tilted at 30 degree, target coverage, HI, CI were improved, and the dose delivered to OAR was reduced compared with conventional supine position in brain radiation therapy. This work was supported by the Radiation Technology R&D program (No. 2013M2A2A7043498) and the Mid

  18. Radiation therapy -- skin care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000735.htm Radiation therapy - skin care To use the sharing features ... this page, please enable JavaScript. When you have radiation treatment for cancer, you may have some changes ...

  19. Convex reformulation of biologically-based multi-criteria intensity-modulated radiation therapy optimization including fractionation effects

    Science.gov (United States)

    Hoffmann, Aswin L.; den Hertog, Dick; Siem, Alex Y. D.; Kaanders, Johannes H. A. M.; Huizenga, Henk

    2008-11-01

    Finding fluence maps for intensity-modulated radiation therapy (IMRT) can be formulated as a multi-criteria optimization problem for which Pareto optimal treatment plans exist. To account for the dose-per-fraction effect of fractionated IMRT, it is desirable to exploit radiobiological treatment plan evaluation criteria based on the linear-quadratic (LQ) cell survival model as a means to balance the radiation benefits and risks in terms of biologic response. Unfortunately, the LQ-model-based radiobiological criteria are nonconvex functions, which make the optimization problem hard to solve. We apply the framework proposed by Romeijn et al (2004 Phys. Med. Biol. 49 1991-2013) to find transformations of LQ-model-based radiobiological functions and establish conditions under which transformed functions result in equivalent convex criteria that do not change the set of Pareto optimal treatment plans. The functions analysed are: the LQ-Poisson-based model for tumour control probability (TCP) with and without inter-patient heterogeneity in radiation sensitivity, the LQ-Poisson-based relative seriality s-model for normal tissue complication probability (NTCP), the equivalent uniform dose (EUD) under the LQ-Poisson model and the fractionation-corrected Probit-based model for NTCP according to Lyman, Kutcher and Burman. These functions differ from those analysed before in that they cannot be decomposed into elementary EUD or generalized-EUD functions. In addition, we show that applying increasing and concave transformations to the convexified functions is beneficial for the piecewise approximation of the Pareto efficient frontier.

  20. Convex reformulation of biologically-based multi-criteria intensity-modulated radiation therapy optimization including fractionation effects.

    Science.gov (United States)

    Hoffmann, Aswin L; den Hertog, Dick; Siem, Alex Y D; Kaanders, Johannes H A M; Huizenga, Henk

    2008-11-21

    Finding fluence maps for intensity-modulated radiation therapy (IMRT) can be formulated as a multi-criteria optimization problem for which Pareto optimal treatment plans exist. To account for the dose-per-fraction effect of fractionated IMRT, it is desirable to exploit radiobiological treatment plan evaluation criteria based on the linear-quadratic (LQ) cell survival model as a means to balance the radiation benefits and risks in terms of biologic response. Unfortunately, the LQ-model-based radiobiological criteria are nonconvex functions, which make the optimization problem hard to solve. We apply the framework proposed by Romeijn et al (2004 Phys. Med. Biol. 49 1991-2013) to find transformations of LQ-model-based radiobiological functions and establish conditions under which transformed functions result in equivalent convex criteria that do not change the set of Pareto optimal treatment plans. The functions analysed are: the LQ-Poisson-based model for tumour control probability (TCP) with and without inter-patient heterogeneity in radiation sensitivity, the LQ-Poisson-based relative seriality s-model for normal tissue complication probability (NTCP), the equivalent uniform dose (EUD) under the LQ-Poisson model and the fractionation-corrected Probit-based model for NTCP according to Lyman, Kutcher and Burman. These functions differ from those analysed before in that they cannot be decomposed into elementary EUD or generalized-EUD functions. In addition, we show that applying increasing and concave transformations to the convexified functions is beneficial for the piecewise approximation of the Pareto efficient frontier.

  1. Optimization of an on-board imaging system for extremely rapid radiation therapy

    Science.gov (United States)

    Cherry Kemmerling, Erica M.; Wu, Meng; Yang, He; Maxim, Peter G.; Loo, Billy W.; Fahrig, Rebecca

    2015-01-01

    Purpose: Next-generation extremely rapid radiation therapy systems could mitigate the need for motion management, improve patient comfort during the treatment, and increase patient throughput for cost effectiveness. Such systems require an on-board imaging system that is competitively priced, fast, and of sufficiently high quality to allow good registration between the image taken on the day of treatment and the image taken the day of treatment planning. In this study, three different detectors for a custom on-board CT system were investigated to select the best design for integration with an extremely rapid radiation therapy system. Methods: Three different CT detectors are proposed: low-resolution (all 4 × 4 mm pixels), medium-resolution (a combination of 4 × 4 mm pixels and 2 × 2 mm pixels), and high-resolution (all 1 × 1 mm pixels). An in-house program was used to generate projection images of a numerical anthropomorphic phantom and to reconstruct the projections into CT datasets, henceforth called “realistic” images. Scatter was calculated using a separate Monte Carlo simulation, and the model included an antiscatter grid and bowtie filter. Diagnostic-quality images of the phantom were generated to represent the patient scan at the time of treatment planning. Commercial deformable registration software was used to register the diagnostic-quality scan to images produced by the various on-board detector configurations. The deformation fields were compared against a “gold standard” deformation field generated by registering initial and deformed images of the numerical phantoms that were used to make the diagnostic and treatment-day images. Registrations of on-board imaging system data were judged by the amount their deformation fields differed from the corresponding gold standard deformation fields—the smaller the difference, the better the system. To evaluate the registrations, the pointwise distance between gold standard and realistic registration

  2. Optimization of beam angles for intensity modulated radiation therapy treatment planning using genetic algorithm on a distributed computing platform.

    Science.gov (United States)

    Nazareth, Daryl P; Brunner, Stephen; Jones, Matthew D; Malhotra, Harish K; Bakhtiari, Mohammad

    2009-07-01

    Planning intensity modulated radiation therapy (IMRT) treatment involves selection of several angle parameters as well as specification of structures and constraints employed in the optimization process. Including these parameters in the combinatorial search space vastly increases the computational burden, and therefore the parameter selection is normally performed manually by a clinician, based on clinical experience. We have investigated the use of a genetic algorithm (GA) and distributed-computing platform to optimize the gantry angle parameters and provide insight into additional structures, which may be necessary, in the dose optimization process to produce optimal IMRT treatment plans. For an IMRT prostate patient, we produced the first generation of 40 samples, each of five gantry angles, by selecting from a uniform random distribution, subject to certain adjacency and opposition constraints. Dose optimization was performed by distributing the 40-plan workload over several machines running a commercial treatment planning system. A score was assigned to each resulting plan, based on how well it satisfied clinically-relevant constraints. The second generation of 40 samples was produced by combining the highest-scoring samples using techniques of crossover and mutation. The process was repeated until the sixth generation, and the results compared with a clinical (equally-spaced) gantry angle configuration. In the sixth generation, 34 of the 40 GA samples achieved better scores than the clinical plan, with the best plan showing an improvement of 84%. Moreover, the resulting configuration of beam angles tended to cluster toward the patient's sides, indicating where the inclusion of additional structures in the dose optimization process may avoid dose hot spots. Additional parameter selection in IMRT leads to a large-scale computational problem. We have demonstrated that the GA combined with a distributed-computing platform can be applied to optimize gantry angle

  3. Radiation Therapy - Multiple Languages

    Science.gov (United States)

    ... W XYZ List of All Topics All Radiation Therapy - Multiple Languages To use the sharing features on this page, ... Information Translations Vietnamese (Tiếng Việt) Expand Section Radiation Therapy - Tiếng Việt (Vietnamese) ... Health Information Translations Characters not displaying correctly on this page? See language display issues . Return to the MedlinePlus Health Information ...

  4. The integration of DVH-based planning aspects into a convex intensity modulated radiation therapy optimization framework.

    Science.gov (United States)

    Kratt, Karin; Scherrer, Alexander

    2009-06-21

    The formulation of intensity modulated radiation therapy (IMRT) planning aspects frequently uses the dose-volume histogram (DVH), whereas plan computations often happen in the more desirable convex IMRT optimization framework. Inspired by a recent publication of Zinchenko et al (2008 Phys. Med. Biol. 53 3231-50), this work addresses the integration of DVH-based planning aspects into this framework from a general point of view. It first provides the basic mathematical requirements on the evaluation functions in order to support such an incorporation. Then it introduces the condition number as a description for how precisely DVH-based planning aspects can be reformulated in terms of evaluation functions. Exemplary numerical studies for the generalized equivalent uniform dose and a physical constraint function show the influence of function parameter values and DVH approximation on the condition number. The work concludes by formulating the aspects that should be taken into account for an appropriate integration of DVH-based planning aspects.

  5. Beam Orientation Optimization for Intensity Modulated Radiation Therapy using Adaptive l1 Minimization

    CERN Document Server

    Jia, Xun; Lou, Yifei; Jiang, Steve B

    2011-01-01

    Beam orientation optimization (BOO) is a key component in the process of IMRT treatment planning. It determines to what degree one can achieve a good treatment plan quality in the subsequent plan optimization process. In this paper, we have developed a BOO algorithm via adaptive l_1 minimization. Specifically, we introduce a sparsity energy function term into our model which contains weighting factors for each beam angle adaptively adjusted during the optimization process. Such an energy term favors small number of beam angles. By optimizing a total energy function containing a dosimetric term and the sparsity term, we are able to identify the unimportant beam angles and gradually remove them without largely sacrificing the dosimetric objective. In one typical prostate case, the convergence property of our algorithm, as well as the how the beam angles are selected during the optimization process, is demonstrated. Fluence map optimization (FMO) is then performed based on the optimized beam angles. The resulted...

  6. Radiation therapy in horses.

    Science.gov (United States)

    Fidel, Janean L

    2010-04-01

    Although the diagnosis of cancer is relatively uncommon in horses, tumors do occur in this species. Surgery, radiation, and chemotherapy are traditional cancer treatments in all species. In equine patients, surgery has often been the only treatment offered; however, not all tumors can be controlled with surgery alone. In small animal oncology, newer and better therapies are in demand and available. Radiation therapy is often used to control or palliate tumors locally, especially to satisfy clients who demand sophisticated treatments. The large size of equine patients can make radiation therapy difficult, but it is a valuable tool for treating cancer and should not be overlooked when treating horses.

  7. Design of an Yb-169 source optimized for gold nanoparticle-aided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Reynoso, Francisco J.; Manohar, Nivedh [Nuclear/Radiological Engineering and Medical Physics Programs, Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States); Krishnan, Sunil [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Cho, Sang Hyun, E-mail: scho@mdanderson.org [Department of Radiation Physics and Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2014-10-15

    Purpose: To find an optimum design of a new high-dose rate ytterbium (Yb)-169 brachytherapy source that would maximize the dose enhancement during gold nanoparticle-aided radiation therapy (GNRT), while meeting practical constraints for manufacturing a clinically relevant brachytherapy source. Methods: Four different Yb-169 source designs were considered in this investigation. The first three source models had a single encapsulation made of one of the following materials: aluminum, titanium, and stainless steel. The last source model adopted a dual encapsulation design with an inner aluminum capsule surrounding the Yb-core and an outer titanium capsule. Monte Carlo (MC) simulations using the Monte Carlo N-Particle code version 5 (MCNP5) were conducted initially to investigate the spectral changes caused by these four source designs and the associated variations in macroscopic dose enhancement across the tumor loaded with gold nanoparticles (GNPs) at 0.7% by weight. Subsequent MC simulations were performed using the EGSnrc and NOREC codes to determine the secondary electron spectra and microscopic dose enhancement as a result of irradiating the GNP-loaded tumor with the MCNP-calculated source spectra. Results: Effects of the source filter design were apparent in the current MC results. The intensity-weighted average energy of the Yb-169 source varied from 108.9 to 122.9 keV, as the source encapsulation material changed from aluminum to stainless steel. Accordingly, the macroscopic dose enhancement calculated at 1 cm away from the source changed from 51.0% to 45.3%. The sources encapsulated by titanium and aluminum/titanium combination showed similar levels of dose enhancement, 49.3% at 1 cm, and average energies of 113.0 and 112.3 keV, respectively. While the secondary electron spectra due to the investigated source designs appeared to look similar in general, some differences were noted especially in the low energy region (<50 keV) of the spectra suggesting the

  8. Whole breast radiation therapy

    Science.gov (United States)

    ... 11, 2016. www.cancer.gov/types/breast/hp/breast-treatment-pdq . Accessed September 13, 2016. National Cancer Institute. Radiation therapy and you: support for people who have cancer. Cancer.gov Web ...

  9. Explicit optimization of plan quality measures in intensity-modulated radiation therapy treatment planning.

    Science.gov (United States)

    Engberg, Lovisa; Forsgren, Anders; Eriksson, Kjell; Hårdemark, Björn

    2017-06-01

    To formulate convex planning objectives of treatment plan multicriteria optimization with explicit relationships to the dose-volume histogram (DVH) statistics used in plan quality evaluation. Conventional planning objectives are designed to minimize the violation of DVH statistics thresholds using penalty functions. Although successful in guiding the DVH curve towards these thresholds, conventional planning objectives offer limited control of the individual points on the DVH curve (doses-at-volume) used to evaluate plan quality. In this study, we abandon the usual penalty-function framework and propose planning objectives that more closely relate to DVH statistics. The proposed planning objectives are based on mean-tail-dose, resulting in convex optimization. We also demonstrate how to adapt a standard optimization method to the proposed formulation in order to obtain a substantial reduction in computational cost. We investigated the potential of the proposed planning objectives as tools for optimizing DVH statistics through juxtaposition with the conventional planning objectives on two patient cases. Sets of treatment plans with differently balanced planning objectives were generated using either the proposed or the conventional approach. Dominance in the sense of better distributed doses-at-volume was observed in plans optimized within the proposed framework. The initial computational study indicates that the DVH statistics are better optimized and more efficiently balanced using the proposed planning objectives than using the conventional approach. © 2017 American Association of Physicists in Medicine.

  10. Robust plan optimization using edge-enhanced intensity for intrafraction organ deformation in prostate intensity-modulated radiation therapy.

    Science.gov (United States)

    Sumida, Iori; Yamaguchi, Hajime; Das, Indra J; Anetai, Yusuke; Kizaki, Hisao; Aboshi, Keiko; Tsujii, Mari; Yamada, Yuji; Tamari, Keisuke; Seo, Yuji; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko

    2017-01-01

    This study evaluated a method for prostate intensity-modulated radiation therapy (IMRT) based on edge-enhanced (EE) intensity in the presence of intrafraction organ deformation using the data of 37 patients treated with step-and-shoot IMRT. On the assumption that the patient setup error was already accounted for by image guidance, only organ deformation over the treatment course was considered. Once the clinical target volume (CTV), rectum, and bladder were delineated and assigned dose constraints for dose optimization, each voxel in the CTV derived from the DICOM RT-dose grid could have a stochastic dose from the different voxel location according to the probability density function as an organ deformation. The stochastic dose for the CTV was calculated as the mean dose at the location through changing the voxel location randomly 1000 times. In the EE approach, the underdose region in the CTV was delineated and optimized with higher dose constraints that resulted in an edge-enhanced intensity beam to the CTV. This was compared to a planning target volume (PTV) margin (PM) approach in which a CTV to PTV margin equivalent to the magnitude of organ deformation was added to obtain an optimized dose distribution. The total monitor units, number of segments, and conformity index were compared between the two approaches, and the dose based on the organ deformation of the CTV, rectum, and bladder was evaluated. The total monitor units, number of segments, and conformity index were significantly lower with the EE approach than with the PM approach, while maintaining the dose coverage to the CTV with organ deformation. The dose to the rectum and bladder were significantly reduced in the EE approach compared with the PM approach. We conclude that the EE approach is superior to the PM with regard to intrafraction organ deformation.

  11. Inverse planning in the age of digital LINACs: station parameter optimized radiation therapy (SPORT)

    Science.gov (United States)

    Xing, Lei; Li, Ruijiang

    2014-03-01

    The last few years have seen a number of technical and clinical advances which give rise to a need for innovations in dose optimization and delivery strategies. Technically, a new generation of digital linac has become available which offers features such as programmable motion between station parameters and high dose-rate Flattening Filter Free (FFF) beams. Current inverse planning methods are designed for traditional machines and cannot accommodate these features of new generation linacs without compromising either dose conformality and/or delivery efficiency. Furthermore, SBRT is becoming increasingly important, which elevates the need for more efficient delivery, improved dose distribution. Here we will give an overview of our recent work in SPORT designed to harness the digital linacs and highlight the essential components of SPORT. We will summarize the pros and cons of traditional beamlet-based optimization (BBO) and direct aperture optimization (DAO) and introduce a new type of algorithm, compressed sensing (CS)-based inverse planning, that is capable of automatically removing the redundant segments during optimization and providing a plan with high deliverability in the presence of a large number of station control points (potentially non-coplanar, non-isocentric, and even multi-isocenters). We show that CS-approach takes the interplay between planning and delivery into account and allows us to balance the dose optimality and delivery efficiency in a controlled way and, providing a viable framework to address various unmet demands of the new generation linacs. A few specific implementation strategies of SPORT in the forms of fixed-gantry and rotational arc delivery are also presented.

  12. A systematic approach to determine optimal composition of gel used in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yuan-Jen [Department of Management Information Systems, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Institute of Biomedical Engineering and Material Science, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Hsieh, Bor-Tsung, E-mail: bthsieh@ctust.edu.tw [Department of Biomedical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Liang, Ji-An [Department of Radiation Oncology, China Medical University Hospital, Taichung, Taiwan (China)

    2011-10-01

    The design of experiment was used to find the optimal composition of N-isopropyl acrylamide (NIPAM) gel. Optical computed tomography was used to scan the polymer gel dosimeter, which was irradiated from 0 to 20 Gy. The study was conducted following a statistical method using a two-level fractional factorial plan involving four variables (gelatin-5% and 6%, NIPAM-3% and 5%, Bis-2.5% and 3%, and THPC-5 and 10 mM). We produced three batches of gels of the same composition to replicate the experiments. Based on the statistical analysis, a regression model was built. The optimal gel composition for the dose range 0-15 Gy with linearity up to 1.000 is as follows: gelatin (5.67%), NIPAM (5%), Bis (2.56%), and THPC (10 mM). The dose response of the NIPAM polymer gel attains stability about 24 h after irradiation and remains stable up to 3 months.

  13. Guaranteed epsilon-optimal treatment plans with minimum number of beams for stereotactic body radiation therapy

    CERN Document Server

    Yarmand, Hamed

    2013-01-01

    Stereotactic body radiotherapy (SBRT) is characterized by delivering a high amount of dose in a short period of time. In SBRT the dose is delivered using open fields (e.g., beam's-eye-view) known as "apertures". Mathematical methods can be used for optimizing treatment planning for delivery of sufficient dose to the cancerous cells while keeping the dose to surrounding organs at risk (OARs) minimal. Two important elements of a treatment plan are quality and delivery time. Quality of a plan is measured based on the target coverage and dose to OARs. Delivery time heavily depends on the number of beams used in the plan since the setup times for different beam directions constitute a large portion of the delivery time. Therefore the ideal plan, in which all potential beams can be used simultaneously, will be associated with a long impractical delivery time. We use the dose to OARs in the ideal plan to find the plan with the minimum number of beams which is guaranteed to be epsilon-optimal (i.e., a predetermined m...

  14. Involved Node Radiation Therapy

    DEFF Research Database (Denmark)

    Maraldo, Maja V; Aznar, Marianne C; Vogelius, Ivan R

    2012-01-01

    PURPOSE: The involved node radiation therapy (INRT) strategy was introduced for patients with Hodgkin lymphoma (HL) to reduce the risk of late effects. With INRT, only the originally involved lymph nodes are irradiated. We present treatment outcome in a retrospective analysis using this strategy...... to 36 Gy). Patients attended regular follow-up visits until 5 years after therapy. RESULTS: The 4-year freedom from disease progression was 96.4% (95% confidence interval: 92.4%-100.4%), median follow-up of 50 months (range: 4-71 months). Three relapses occurred: 2 within the previous radiation field......, and 1 in a previously uninvolved region. The 4-year overall survival was 94% (95% confidence interval: 88.8%-99.1%), median follow-up of 58 months (range: 4-91 months). Early radiation therapy toxicity was limited to grade 1 (23.4%) and grade 2 (13.8%). During follow-up, 8 patients died, none from HL, 7...

  15. Radiation therapy physics

    CERN Document Server

    1995-01-01

    The aim of this book is to provide a uniquely comprehensive source of information on the entire field of radiation therapy physics. The very significant advances in imaging, computational, and accelerator technologies receive full consideration, as do such topics as the dosimetry of radiolabeled antibodies and dose calculation models. The scope of the book and the expertise of the authors make it essential reading for interested physicians and physicists and for radiation dosimetrists.

  16. Planning Target Volume D95 and Mean Dose Should Be Considered for Optimal Local Control for Stereotactic Ablative Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lina [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhou, Shouhao [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Balter, Peter [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Shen, Chan [Department of Health Service Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gomez, Daniel R.; Welsh, James D.; Lin, Steve H. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-07-15

    Purpose: To identify the optimal dose parameters predictive for local/lobar control after stereotactic ablative radiation therapy (SABR) in early-stage non-small cell lung cancer (NSCLC). Methods and Materials: This study encompassed a total of 1092 patients (1200 lesions) with NSCLC of clinical stage T1-T2 N0M0 who were treated with SABR of 50 Gy in 4 fractions or 70 Gy in 10 fractions, depending on tumor location/size, using computed tomography-based heterogeneity corrections and a convolution superposition calculation algorithm. Patients were monitored by chest CT or positron emission tomography/CT and/or biopsy after SABR. Factors predicting local/lobar recurrence (LR) were determined by competing risk multivariate analysis. Continuous variables were divided into 2 subgroups at cutoff values identified by receiver operating characteristic curves. Results: At a median follow-up time of 31.7 months (interquartile range, 14.8-51.3 months), the 5-year time to local recurrence within the same lobe and overall survival rates were 93.8% and 44.8%, respectively. Total cumulative number of patients experiencing LR was 40 (3.7%), occurring at a median time of 14.4 months (range, 4.8-46 months). Using multivariate competing risk analysis, independent predictive factors for LR after SABR were minimum biologically effective dose (BED{sub 10}) to 95% of planning target volume (PTVD95 BED{sub 10}) ≤86 Gy (corresponding to PTV D95 physics dose of 42 Gy in 4 fractions or 55 Gy in 10 fractions) and gross tumor volume ≥8.3 cm{sup 3}. The PTVmean BED{sub 10} was highly correlated with PTVD95 BED{sub 10.} In univariate analysis, a cutoff of 130 Gy for PTVmean BED{sub 10} (corresponding to PTVmean physics dose of 55 Gy in 4 fractions or 75 Gy in 10 fractions) was also significantly associated with LR. Conclusions: In addition to gross tumor volume, higher radiation dose delivered to the PTV predicts for better local/lobar control. We recommend that both PTVD95 BED

  17. Optimal schedules of fractionated radiation therapy by way of the greedy principle: biologically-based adaptive boosting

    Science.gov (United States)

    Hanin, Leonid; Zaider, Marco

    2014-08-01

    We revisit a long-standing problem of optimization of fractionated radiotherapy and solve it in considerable generality under the following three assumptions only: (1) repopulation of clonogenic cancer cells between radiation exposures follows linear birth-and-death Markov process; (2) clonogenic cancer cells do not interact with each other; and (3) the dose response function s(D) is decreasing and logarithmically concave. Optimal schedules of fractionated radiation identified in this work can be described by the following ‘greedy’ principle: give the maximum possible dose as soon as possible. This means that upper bounds on the total dose and the dose per fraction reflecting limitations on the damage to normal tissue, along with a lower bound on the time between successive fractions of radiation, determine the optimal radiation schedules completely. Results of this work lead to a new paradigm of dose delivery which we term optimal biologically-based adaptive boosting (OBBAB). It amounts to (a) subdividing the target into regions that are homogeneous with respect to the maximum total dose and maximum dose per fraction allowed by the anatomy and biological properties of the normal tissue within (or adjacent to) the region in question and (b) treating each region with an individual optimal schedule determined by these constraints. The fact that different regions may be treated to different total dose and dose per fraction mean that the number of fractions may also vary between regions. Numerical evidence suggests that OBBAB produces significantly larger tumor control probability than the corresponding conventional treatments.

  18. Optimal duration of androgen deprivation therapy following radiation therapy in intermediate- or high-risk non-metastatic prostate cancer: a systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Frederico; Figueiredo, Maximiliano Augusto Novis de; Sasse, Andre Deeke, E-mail: sasse@cevon.com.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

    2015-05-15

    Objectives: to investigate current evidence on the optimal duration of adjuvant hormone deprivation for prostate cancer treated with radiation therapy with curative intent. Materials and Methods: A systematic search was performed in electronic databases. Data from randomized trials comparing different durations of hormone blockade was collected for pooled analysis. Overall survival, disease-free survival, disease-specific survival and toxicity were the outcomes of interest. Meta-analyses were performed using random-effects model. Results: Six studies met the eligibility criteria. For overall survival, the pooled data from the studies demonstrated a statistically significant benefit for longer hormone deprivation (Hazard Ratio 0.84; 95% CI 0.74 - 0.96). A statistically significant benefit was also found for disease-free survival (Hazard Ratio 0.74; 95% CI 0.62 - 0.89), and disease-specific survival (Hazard Ratio 0.73; 95% CI 0.62 - 0.85). Studies with longer blockade duration arm demonstrated greater benefit. Toxicity was low, with no increase in cardiovascular events. Conclusions: Longer duration of androgen deprivation combined to radiotherapy prolongs OS, DFS and DSS in patients with intermediate and high-risk non-metastatic prostate cancer. However, this evidence is based on trials using older radiation techniques, and further research of combination of androgen deprivation and new RT technologies may be warranted. (author)

  19. Modeling Internal Radiation Therapy

    NARCIS (Netherlands)

    van den Broek, Egon; Schouten, Theo E.; Pellegrini, M.; Fred, A.; Filipe, J.; Gamboa, H.

    2011-01-01

    A new technique is described to model (internal) radiation therapy. It is founded on morphological processing, in particular distance transforms. Its formal basis is presented as well as its implementation via the Fast Exact Euclidean Distance (FEED) transform. Its use for all variations of internal

  20. Radiation Therapy for Gynecologic Cancers

    Science.gov (United States)

    ... 000 members who specialize in treating cancer with radiation therapies. ASTRO is dedicated to improving patient care through ... rtanswers.org © ASTRO 2016 PRINTED ON RECYCLED PAPER Radiation Therapy for Gynecologic Cancers Gynecologic cancers include malignancies of ...

  1. Radiation Therapy: Additional Treatment Options

    Science.gov (United States)

    ... Cancer Upper GI Cancers Search x FIND A RADIATION ONCOLOGIST CLOSE SNIPEND TREATMENT TYPES SNIPSTART Home / Treatment ... novel targeted therapies can act as radiosensitizers. Systemic Radiation Therapy Certain cancers may be treated with radioactive ...

  2. [Nanoparticles and radiation therapy].

    Science.gov (United States)

    Calugaru, Valentin; Magné, Nicolas; Hérault, Joel; Bonvalot, Sylvie; Le Tourneau, Christophe; Thariat, Juliette

    2015-01-01

    Nanoparticles have emerged in oncology as new therapeutic agents of distinct biochemical and physical properties, and pharmacokinetics. Current rationale and clinical applications in combination with radiation therapy were analyzed. A review of the literature was conducted on nanoparticles as radiosensitizers, with a focus on metallic nanoparticles and radiosensitization mechanisms. Nanoparticles are mainly used as vectors for drugs or to potentiate dose deposit selectively in irradiated tissues. Preclinical data suggest a predominating effect in the kilovoltage range through a photoelectric effect and a potential in the megavoltage range under a combination of physical and biochemical (diameter, concentration, site of infusion etc) conditions. Several clinical trials are ongoing with metallic/crystalline nanoparticles. Nanoparticles have shown a potential for better therapeutic index with radiation therapy, which is being increasingly investigated clinically. Copyright © 2014 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  3. [Cardiac effects of radiation therapy].

    Science.gov (United States)

    Tuohinen, Suvi; Turpeinen, Anu; Skyttä, Tanja; Kellokumpu-Lehtinen, Pirkko-Liisa

    2015-01-01

    Because of increased life-expentancy cancer patients having undergone radiation therapy nowadays live longer, and late-appearing adverse effects are therefore playing a more significant role. Radiation therapy given to the chest is known to approximately double the risk of heart disease, the cumulative total radiation dose being the most important risk-increasing factor. The most significant adverse effects appear only years after the treatment. The mortality from late manifestations reduces the total benefit of radiation therapy. Patients with radiation therapy due to a cancer of the left breast or Hodgkin's lymphoma are particularly susceptible to cardiac effects. A safe radiation dose is not known.

  4. A practical cone-beam CT scatter correction method with optimized Monte Carlo simulations for image-guided radiation therapy

    Science.gov (United States)

    Xu, Yuan; Bai, Ti; Yan, Hao; Ouyang, Luo; Pompos, Arnold; Wang, Jing; Zhou, Linghong; Jiang, Steve B.; Jia, Xun

    2015-05-01

    Cone-beam CT (CBCT) has become the standard image guidance tool for patient setup in image-guided radiation therapy. However, due to its large illumination field, scattered photons severely degrade its image quality. While kernel-based scatter correction methods have been used routinely in the clinic, it is still desirable to develop Monte Carlo (MC) simulation-based methods due to their accuracy. However, the high computational burden of the MC method has prevented routine clinical application. This paper reports our recent development of a practical method of MC-based scatter estimation and removal for CBCT. In contrast with conventional MC approaches that estimate scatter signals using a scatter-contaminated CBCT image, our method used a planning CT image for MC simulation, which has the advantages of accurate image intensity and absence of image truncation. In our method, the planning CT was first rigidly registered with the CBCT. Scatter signals were then estimated via MC simulation. After scatter signals were removed from the raw CBCT projections, a corrected CBCT image was reconstructed. The entire workflow was implemented on a GPU platform for high computational efficiency. Strategies such as projection denoising, CT image downsampling, and interpolation along the angular direction were employed to further enhance the calculation speed. We studied the impact of key parameters in the workflow on the resulting accuracy and efficiency, based on which the optimal parameter values were determined. Our method was evaluated in numerical simulation, phantom, and real patient cases. In the simulation cases, our method reduced mean HU errors from 44 to 3 HU and from 78 to 9 HU in the full-fan and the half-fan cases, respectively. In both the phantom and the patient cases, image artifacts caused by scatter, such as ring artifacts around the bowtie area, were reduced. With all the techniques employed, we achieved computation time of less than 30 s including the

  5. Radiation Therapy for Skin Cancer

    Science.gov (United States)

    ... make sure they are safe to use during radiation therapy. • Eat a balanced diet. If food tastes ... your fluid intake. • Treat the skin exposed to radiation with special care. Stay out of the sun, ...

  6. Study on external beam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Sook; Yoo, Seoung Yul; Yoo, Hyung Jun; Ji, Young Hoon; Lee, Dong Han; Lee, Dong Hoon; Choi, Mun Sik; Yoo, Dae Heon; Lee, Hyo Nam; Kim, Kyeoung Jung

    1999-04-01

    To develop the therapy technique which promote accuracy and convenience in external radiation therapy, to obtain the development of clinical treatment methods for the global competition. The contents of the R and D were 1. structure, process and outcome analysis in radiation therapy department. 2. Development of multimodality treatment in radiation therapy 3. Development of computation using networking techniques 4. Development of quality assurance (QA) system in radiation therapy 5. Development of radiotherapy tools 6. Development of intraoperative radiation therapy (IORT) tools. The results of the R and D were 1. completion of survey and analysis about Korea radiation therapy status 2. Performing QA analysis about ICR on cervix cancer 3. Trial of multicenter randomized study on lung cancers 4. Setting up inter-departmental LAN using MS NT server and Notes program 5. Development of ionization chamber and dose-rate meter for QA in linear accelerator 6. Development on optimized radiation distribution algorithm for multiple slice 7. Implementation on 3 dimensional volume surface algorithm and 8. Implementation on adaptor and cone for IORT.

  7. Smart Radiation Therapy Biomaterials.

    Science.gov (United States)

    Ngwa, Wilfred; Boateng, Francis; Kumar, Rajiv; Irvine, Darrell J; Formenti, Silvia; Ngoma, Twalib; Herskind, Carsten; Veldwijk, Marlon R; Hildenbrand, Georg Lars; Hausmann, Michael; Wenz, Frederik; Hesser, Juergen

    2017-03-01

    Radiation therapy (RT) is a crucial component of cancer care, used in the treatment of over 50% of cancer patients. Patients undergoing image guided RT or brachytherapy routinely have inert RT biomaterials implanted into their tumors. The single function of these RT biomaterials is to ensure geometric accuracy during treatment. Recent studies have proposed that the inert biomaterials could be upgraded to "smart" RT biomaterials, designed to do more than 1 function. Such smart biomaterials include next-generation fiducial markers, brachytherapy spacers, and balloon applicators, designed to respond to stimuli and perform additional desirable functions like controlled delivery of therapy-enhancing payloads directly into the tumor subvolume while minimizing normal tissue toxicities. More broadly, smart RT biomaterials may include functionalized nanoparticles that can be activated to boost RT efficacy. This work reviews the rationale for smart RT biomaterials, the state of the art in this emerging cross-disciplinary research area, challenges and opportunities for further research and development, and a purview of potential clinical applications. Applications covered include using smart RT biomaterials for boosting cancer therapy with minimal side effects, combining RT with immunotherapy or chemotherapy, reducing treatment time or health care costs, and other incipient applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. The physics of radiation therapy

    CERN Document Server

    Khan, Faiz M

    2009-01-01

    Dr. Khan's classic textbook on radiation oncology physics is now in its thoroughly revised and updated Fourth Edition. It provides the entire radiation therapy team—radiation oncologists, medical physicists, dosimetrists, and radiation therapists—with a thorough understanding of the physics and practical clinical applications of advanced radiation therapy technologies, including 3D-CRT, stereotactic radiotherapy, HDR, IMRT, IGRT, and proton beam therapy. These technologies are discussed along with the physical concepts underlying treatment planning, treatment delivery, and dosimetry. This Fourth Edition includes brand-new chapters on image-guided radiation therapy (IGRT) and proton beam therapy. Other chapters have been revised to incorporate the most recent developments in the field. This edition also features more than 100 full-color illustrations throughout.

  9. Different Approaches in Radiation Therapy

    Directory of Open Access Journals (Sweden)

    Rolf-Dieter eKortmann

    2011-12-01

    Full Text Available Radiation therapy is a cornerstone in the therapeutic management of craniopharyngioma. The close proximity to neighbouring eloquent structures pose a particular challenge to radiation therapy. Modern treatment technologies including fractionated 3-d conformal radiotherapy, intensity modulated radiation therapy and recently proton therapy are able to precisely cover the target while preserving surrounding tissue,Tumour controls between 80 and in access of 90 % can be achieved. Alternative treatments consisting of radiosurgery, intracavitary application of isotopes and brachytherapy also offer an acceptable tumour control and might be given in selected cases. More research is needed to establish the role of each treatment modality.

  10. Real-time Tumor Oxygenation Changes After Single High-dose Radiation Therapy in Orthotopic and Subcutaneous Lung Cancer in Mice: Clinical Implication for Stereotactic Ablative Radiation Therapy Schedule Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Song, Changhoon [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Hong, Beom-Ju; Bok, Seoyeon; Lee, Chan-Ju; Kim, Young-Eun [Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Gyeongbuk (Korea, Republic of); Jeon, Sang-Rok [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of); Wu, Hong-Gyun [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Yun-Sang [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cheon, Gi Jeong; Paeng, Jin Chul [Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Carlson, David J. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); and others

    2016-07-01

    Purpose: To investigate the serial changes of tumor hypoxia in response to single high-dose irradiation by various clinical and preclinical methods to propose an optimal fractionation schedule for stereotactic ablative radiation therapy. Methods and Materials: Syngeneic Lewis lung carcinomas were grown either orthotopically or subcutaneously in C57BL/6 mice and irradiated with a single dose of 15 Gy to mimic stereotactic ablative radiation therapy used in the clinic. Serial [{sup 18}F]-misonidazole (F-MISO) positron emission tomography (PET) imaging, pimonidazole fluorescence-activated cell sorting analyses, hypoxia-responsive element-driven bioluminescence, and Hoechst 33342 perfusion were performed before irradiation (day −1), at 6 hours (day 0), and 2 (day 2) and 6 (day 6) days after irradiation for both subcutaneous and orthotopic lung tumors. For F-MISO, the tumor/brain ratio was analyzed. Results: Hypoxic signals were too low to quantitate for orthotopic tumors using F-MISO PET or hypoxia-responsive element-driven bioluminescence imaging. In subcutaneous tumors, the maximum tumor/brain ratio was 2.87 ± 0.483 at day −1, 1.67 ± 0.116 at day 0, 2.92 ± 0.334 at day 2, and 2.13 ± 0.385 at day 6, indicating that tumor hypoxia was decreased immediately after irradiation and had returned to the pretreatment levels at day 2, followed by a slight decrease by day 6 after radiation. Pimonidazole analysis also revealed similar patterns. Using Hoechst 33342 vascular perfusion dye, CD31, and cleaved caspase 3 co-immunostaining, we found a rapid and transient vascular collapse, which might have resulted in poor intratumor perfusion of F-MISO PET tracer or pimonidazole delivered at day 0, leading to decreased hypoxic signals at day 0 by PET or pimonidazole analyses. Conclusions: We found tumor hypoxia levels decreased immediately after delivery of a single dose of 15 Gy and had returned to the pretreatment levels 2 days after irradiation and had decreased

  11. External Validation and Optimization of International Consensus Clinical Target Volumes for Adjuvant Radiation Therapy in Bladder Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Abhinav V. [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Christodouleas, John P. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Wu, Tianming [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Smith, Norman D.; Steinberg, Gary D. [Section of Urology, Department of Surgery, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Liauw, Stanley L., E-mail: sliauw@radonc.uchicago.edu [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States)

    2017-03-15

    Purpose: International consensus (IC) clinical target volumes (CTVs) have been proposed to standardize radiation field design in the treatment of patients at high risk of locoregional failure (LRF) after radical cystectomy. The purpose of this study was to externally validate the IC CTVs in a cohort of postsurgical patients followed up for LRF and identify revisions that might improve the IC CTVs' performance. Methods and Materials: Among 334 patients with pT3 to pT4 bladder cancer treated with radical cystectomy, LRF developed in 58 (17%), of whom 52 had computed tomography scans available for review. Images with LRF were exported into a treatment planning system, and IC CTVs were contoured and evaluated for adequacy of coverage of each LRF with respect to both the patient and each of 6 pelvic subsites: common iliac (CI) region, obturator region (OR), external and internal iliac region, presacral region, cystectomy bed, or other pelvic site. Revisions to the IC contours were proposed based on the findings. Results: Of the 52 patients with documented LRF, 13 (25%) had LRFs that were outside of the IC CTV involving 17 pelvic subsites: 5 near the CI CTV, 5 near the OR CTV, 1 near the external and internal iliac region, and 6 near the cystectomy bed. The 5 CI failures were located superior to the CTV, and the 5 OR failures were located medial to the CTV. Increasing the superior boundary of the CI to a vessel-based definition of the aortic bifurcation, as well as increasing the medial extension of the OR by an additional 9 mm, decreased the number of patients with LRF outside of the IC CTV to 7 (13%). Conclusions: Modified IC CTVs inclusive of a slight adjustment superiorly for the CI region and medially for the OR may reduce the risk of pelvic failure in patients treated with adjuvant radiation therapy.

  12. Radiation Therapy for Lung Cancer

    Science.gov (United States)

    ... is almost always due to smoking. TREATING LUNG CANCER Lung cancer treatment depends on several factors, including the ... org TARGETING CANCER CARE Radiation Therapy for Lung Cancer Lung cancer is the second most common cancer in ...

  13. Optimizing intraoperative fluid therapy.

    Science.gov (United States)

    Stephens, Robert; Mythen, Monty

    2003-08-01

    Correcting the fluid status of the surgical patient is an integral part of good anaesthetic practice. There have been few areas in anaesthesia and perioperative medicine as controversial as fluid resuscitation. Uncertainties still exist as to what the best solution to give is, whether it be a colloid or a crystalloid, and how and when to give it. As well as increasing awareness of the different properties of various colloids, there has been interest in the nature of the carrier solutions, essentially a choice between saline or Ringer's lactate (compound sodium lactate or Hartmann's solution). In this article we review recent studies involving crystalloids, the 'new colloids', and on the amount and timing of fluid therapy. Saline based fluids (including most colloids) are associated with a hyperchloremic metabolic acidosis, and a hypocoagulable state, although these may not necessarily harm the patient. Saline may have deleterious effects on renal function. Colloids in solutions similar to Ringer's lactate ('balanced solutions') may avoid these effects although few are currently available. Several studies that have used fluids (along with other therapies) to improve organ perfusion around the time of surgery have been associated with a better outcome. Compared with Ringer's lactate, saline, and saline-based colloids are associated with a hyperchloremic metabolic acidosis, and a hypocoagulable state although they may not be associated with adverse patient outcomes. Increasing awareness of the 'Stewart hypothesis' has led to new ways of managing hyperchloremic metabolic acidosis. The 'crystalloid-colloid debate' continues, and has led to an awareness that these different fluids, along with their carrier solutions are drugs with different effects. Several studies, in which patients have received more fluid in the protocol group, have found better clinical outcomes in the 'optimized' patients.

  14. Proton radiation therapy in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Grein, E.; Duzenli, C.; Pickles, T.; Ma, R.; Paton, K.; Kwa, W.; Harrison, R.; Blackmore, E. [BC Cancer Agency, Vancouver, British Columbia (Canada); TRIUMF, Vancouver, British Columbia (Canada)

    2002-04-01

    The development, commissioning, and implementation of the first Canadian Proton Radiation Therapy facility at TRIUMF in British Columbia is described. This was a collaborative project by the cyclotron physicists and staff at TRIUMF, the medical physicists and radiation oncologists of the Cancer Agency and the ocular oncology physicians of the Eye Care Center at Vancouver Hospital. (author)

  15. k-space sampling optimization for ultrashort TE imaging of cortical bone: Applications in radiation therapy planning and MR-based PET attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Lingzhi, E-mail: hlingzhi@gmail.com, E-mail: raymond.muzic@case.edu; Traughber, Melanie [Philips Healthcare, Cleveland, Ohio 44143 (United States); Su, Kuan-Hao; Pereira, Gisele C.; Grover, Anu; Traughber, Bryan; Muzic, Raymond F. Jr., E-mail: hlingzhi@gmail.com, E-mail: raymond.muzic@case.edu [University Hospitals Case Medical Center, Cleveland, Ohio 44106 (United States)

    2014-10-15

    Purpose: The ultrashort echo-time (UTE) sequence is a promising MR pulse sequence for imaging cortical bone which is otherwise difficult to image using conventional MR sequences and also poses strong attenuation for photons in radiation therapy and PET imaging. The authors report here a systematic characterization of cortical bone signal decay and a scanning time optimization strategy for the UTE sequence through k-space undersampling, which can result in up to a 75% reduction in acquisition time. Using the undersampled UTE imaging sequence, the authors also attempted to quantitatively investigate the MR properties of cortical bone in healthy volunteers, thus demonstrating the feasibility of using such a technique for generating bone-enhanced images which can be used for radiation therapy planning and attenuation correction with PET/MR. Methods: An angularly undersampled, radially encoded UTE sequence was used for scanning the brains of healthy volunteers. Quantitative MR characterization of tissue properties, including water fraction and R2{sup ∗} = 1/T2{sup ∗}, was performed by analyzing the UTE images acquired at multiple echo times. The impact of different sampling rates was evaluated through systematic comparison of the MR image quality, bone-enhanced image quality, image noise, water fraction, and R2{sup ∗} of cortical bone. Results: A reduced angular sampling rate of the UTE trajectory achieves acquisition durations in proportion to the sampling rate and in as short as 25% of the time required for full sampling using a standard Cartesian acquisition, while preserving unique MR contrast within the skull at the cost of a minimal increase in noise level. The R2{sup ∗} of human skull was measured as 0.2–0.3 ms{sup −1} depending on the specific region, which is more than ten times greater than the R2{sup ∗} of soft tissue. The water fraction in human skull was measured to be 60%–80%, which is significantly less than the >90% water fraction in

  16. Method for microbeam radiation therapy

    Science.gov (United States)

    Slatkin, Daniel N.; Dilmanian, F. Avraham; Spanne, Per O.

    1994-01-01

    A method of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation, in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue.

  17. A simple geometric algorithm to predict optimal starting gantry angles using equiangular-spaced beams for intensity modulated radiation therapy of prostate cancer.

    Science.gov (United States)

    Potrebko, Peter S; McCurdy, Boyd M C; Butler, James B; El-Gubtan, Adel S; Nugent, Zoann

    2007-10-01

    A fast, geometric beam angle optimization (BAO) algorithm for clinical intensity-modulated radiation therapy (IMRT) was implemented on ten localized prostate cancer patients on the Radiation Therapy Oncology Group (RTOG) 0126 protocol. The BAO algorithm computed the beam intersection volume (BIV) within the rectum and bladder using five and seven equiangular-spaced beams as a function of starting gantry angle for comparison to the V 75 Gy and V 70 Gy. A mathematical theory was presented to explain the correlation of BIV with dose and dose-volume metrics. The class solution 'W' pattern in the rectal V 75 Gy and V 70 Gy as a function of starting gantry angle using five equiangular-spaced beams (with two separate minima centered near 20 degrees and 50 degrees) was reproduced by the 5 BIV within the rectum. A strong correlation was found between the rectal 5 BIV and the rectal V 75 Gy and V 70 Gy as a function of starting gantry angle. The BAO algorithm predicted the location of the two dosimetric minima in rectal V 75 Gy and V 70 Gy (optimal starting gantry angles) to within 5 degrees. It was demonstrated that the BIV geometric variations for seven equiangular-spaced beams were too small to translate into a strong dosimetric effect in the rectal V 75 Gy and V 70 Gy. The relatively flat distribution with starting gantry angle of the bladder V 75 Gy and V 70 Gy was reproduced by the bladder five and seven BIV for each patient. A geometric BAO method based on BIV has the advantage over dosimetric BAO methods of simplicity and rapid computation time. This algorithm can be used as a standalone optimization method or act as a rapid calculation filter to reduce the search space for a dosimetric BAO method. Given the clinically infeasible computation times of many dosimetric beam orientation optimization algorithms, this robust geometric BIV algorithm has the potential to facilitate beam angle selection for prostate IMRT in clinical practice.

  18. Radiation Therapy in Keloids Treatment: History, Strategy, Effectiveness, and Complication

    Directory of Open Access Journals (Sweden)

    Jing Xu

    2017-01-01

    Conclusions: Both past and present evidence support the idea that combination therapy of radiation and surgical therapy is safe and feasible. However, the optimization of treatment strategy was based on different radiation types and should take dose, fractions, interval, and complications into consideration, which will then decrease the rate of recurrence and increase the level of satisfaction.

  19. Advances in radiation therapy dosimetry

    Directory of Open Access Journals (Sweden)

    Paliwal Bhudatt

    2009-01-01

    Full Text Available During the last decade, there has been an explosion of new radiation therapy planning and delivery tools. We went through a rapid transition from conventional three-dimensional (3D conformal radiation therapy to intensity-modulated radiation therapy (IMRT treatments, and additional new techniques for motion-adaptive radiation therapy are being introduced. These advances push the frontiers in our effort to provide better patient care; and with the addition of IMRT, temporal dimensions are major challenges for the radiotherapy patient dosimetry and delivery verification. Advanced techniques are less tolerant to poor implementation than are standard techniques. Mis-administrations are more difficult to detect and can possibly lead to poor outcomes for some patients. Instead of presenting a manual on quality assurance for radiation therapy, this manuscript provides an overview of dosimetry verification tools and a focused discussion on breath holding, respiratory gating and the applications of four-dimensional computed tomography in motion management. Some of the major challenges in the above areas are discussed.

  20. Radiation therapy in pseudotumour haemarthrosis

    Energy Technology Data Exchange (ETDEWEB)

    Lal, P.; Biswal, B.M.; Thulkar, S.; Patel, A.K.; Venkatesh, R.; Julka, P.K. [Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, Ansari Nagar, New Delhi (India). Departments of Radiation Oncology, Radiodiagnosis and Haematology

    1998-11-01

    Total or partial deficiency of factor VIII and IX in the coagulation cascade leads to haemophilia. Haemophilia affecting weight-bearing joints gives a `pseudotumour` or haemarthrosis-like condition. Surgery and cryoprecipitate infusions have been the treatment for this condition. Radiocolloids and radiation therapy have been used with some benefit. One case of ankle pseudotumour which was treated by low-dose external beam radiation is presented here. Copyright (1998) Blackwell Science Pty Ltd 14 refs., 2 figs.

  1. NMR with Combined Antiangiogenic and Radiation Therapies - Breast Cancer

    National Research Council Canada - National Science Library

    Brown, Stephen

    2000-01-01

    The original goal of the present study was to determine optimal strategies for combining radiation and antiangiogenic therapies in spontaneous murine tumors and to evaluate the potential of Nuclear Magnetic Resonance (NMR...

  2. SU-E-J-16: Automatic Image Contrast Enhancement Based On Automatic Parameter Optimization for Radiation Therapy Setup Verification

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, J [Taishan Medical University, Taian, Shandong (China); Washington University in St Louis, St Louis, MO (United States); Li, H. Harlod; Zhang, T; Yang, D [Washington University in St Louis, St Louis, MO (United States); Ma, F [Taishan Medical University, Taian, Shandong (China)

    2015-06-15

    Purpose: In RT patient setup 2D images, tissues often cannot be seen well due to the lack of image contrast. Contrast enhancement features provided by image reviewing software, e.g. Mosaiq and ARIA, require manual selection of the image processing filters and parameters thus inefficient and cannot be automated. In this work, we developed a novel method to automatically enhance the 2D RT image contrast to allow automatic verification of patient daily setups as a prerequisite step of automatic patient safety assurance. Methods: The new method is based on contrast limited adaptive histogram equalization (CLAHE) and high-pass filtering algorithms. The most important innovation is to automatically select the optimal parameters by optimizing the image contrast. The image processing procedure includes the following steps: 1) background and noise removal, 2) hi-pass filtering by subtracting the Gaussian smoothed Result, and 3) histogram equalization using CLAHE algorithm. Three parameters were determined through an iterative optimization which was based on the interior-point constrained optimization algorithm: the Gaussian smoothing weighting factor, the CLAHE algorithm block size and clip limiting parameters. The goal of the optimization is to maximize the entropy of the processed Result. Results: A total 42 RT images were processed. The results were visually evaluated by RT physicians and physicists. About 48% of the images processed by the new method were ranked as excellent. In comparison, only 29% and 18% of the images processed by the basic CLAHE algorithm and by the basic window level adjustment process, were ranked as excellent. Conclusion: This new image contrast enhancement method is robust and automatic, and is able to significantly outperform the basic CLAHE algorithm and the manual window-level adjustment process that are currently used in clinical 2D image review software tools.

  3. An optimized posterior axillary boost technique in radiation therapy to supraclavicular and axillary lymph nodes: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Victor, E-mail: vhernandezmasgrau@gmail.com [Department of Medical Physics, Hospital Sant Joan de Reus, IISPV, Tarragona (Spain); Arenas, Meritxell [Department of Radiation therapy, Hospital Sant Joan de Reus, IISPV, Tarragona (Spain); Müller, Katrin [Department of Medical Physics, Hospital Sant Joan de Reus, IISPV, Tarragona (Spain); Gomez, David; Bonet, Marta [Department of Radiation therapy, Hospital Sant Joan de Reus, IISPV, Tarragona (Spain)

    2013-01-01

    To assess the advantages of an optimized posterior axillary (AX) boost technique for the irradiation of supraclavicular (SC) and AX lymph nodes. Five techniques for the treatment of SC and levels I, II, and III AX lymph nodes were evaluated for 10 patients selected at random: a direct anterior field (AP); an anterior to posterior parallel pair (AP-PA); an anterior field with a posterior axillary boost (PAB); an anterior field with an anterior axillary boost (AAB); and an optimized PAB technique (OptPAB). The target coverage, hot spots, irradiated volume, and dose to organs at risk were evaluated and a statistical analysis comparison was performed. The AP technique delivered insufficient dose to the deeper AX nodes. The AP-PA technique produced larger irradiated volumes and higher mean lung doses than the other techniques. The PAB and AAB techniques originated excessive hot spots in most of the cases. The OptPAB technique produced moderate hot spots while maintaining a similar planning target volume (PTV) coverage, irradiated volume, and dose to organs at risk. This optimized technique combines the advantages of the PAB and AP-PA techniques, with moderate hot spots, sufficient target coverage, and adequate sparing of normal tissues. The presented technique is simple, fast, and easy to implement in routine clinical practice and is superior to the techniques historically used for the treatment of SC and AX lymph nodes.

  4. An Automated Treatment Plan Quality Control Tool for Intensity-Modulated Radiation Therapy Using a Voxel-Weighting Factor-Based Re-Optimization Algorithm.

    Directory of Open Access Journals (Sweden)

    Ting Song

    Full Text Available Intensity-modulated radiation therapy (IMRT currently plays an important role in radiotherapy, but its treatment plan quality can vary significantly among institutions and planners. Treatment plan quality control (QC is a necessary component for individual clinics to ensure that patients receive treatments with high therapeutic gain ratios. The voxel-weighting factor-based plan re-optimization mechanism has been proved able to explore a larger Pareto surface (solution domain and therefore increase the possibility of finding an optimal treatment plan. In this study, we incorporated additional modules into an in-house developed voxel weighting factor-based re-optimization algorithm, which was enhanced as a highly automated and accurate IMRT plan QC tool (TPS-QC tool. After importing an under-assessment plan, the TPS-QC tool was able to generate a QC report within 2 minutes. This QC report contains the plan quality determination as well as information supporting the determination. Finally, the IMRT plan quality can be controlled by approving quality-passed plans and replacing quality-failed plans using the TPS-QC tool. The feasibility and accuracy of the proposed TPS-QC tool were evaluated using 25 clinically approved cervical cancer patient IMRT plans and 5 manually created poor-quality IMRT plans. The results showed high consistency between the QC report quality determinations and the actual plan quality. In the 25 clinically approved cases that the TPS-QC tool identified as passed, a greater difference could be observed for dosimetric endpoints for organs at risk (OAR than for planning target volume (PTV, implying that better dose sparing could be achieved in OAR than in PTV. In addition, the dose-volume histogram (DVH curves of the TPS-QC tool re-optimized plans satisfied the dosimetric criteria more frequently than did the under-assessment plans. In addition, the criteria for unsatisfied dosimetric endpoints in the 5 poor-quality plans could

  5. Sensitizing Osteosarcoma to Radiation Therapy

    Science.gov (United States)

    Mamo, Tewodros Kebede

    Several strategies to enhance the effects of radiation therapy are being explored for various cancers, with multiple molecular pathways and physical approaches suggested to play a role. One approach to improve the effectiveness of radiation therapy in tumors is the use of radiosensitizing molecules. Among the key radiosensitizing molecules being explored in various cancers include pharmacologic inhibitors of DNA repair and gold nanoparticles that physically enhance the amount of radiation deposited inside cancer cells. The main goal of this thesis is to explore the role of DNA repair inhibition as a radiosensitizing strategy for osteosarcoma cells. Additionally, the thesis investigates the effects of particle size in the application of gold nanoparticles in osteosarcoma cells to help identify the key parameters relevant to choosing an effective gold nanoparticle-based radiosensitizer.

  6. Radiation therapy - questions to ask your doctor

    Science.gov (United States)

    What to ask your doctor about radiation therapy ... National Cancer Institute. Radiation therapy and you: support for people with cancer. Cancer.gov. Updated May 2007. www.cancer.gov/publications/patient-education/radiationttherapy. ...

  7. Uncomplicated and Cancer-Free Control Probability (UCFCP): A new integral approach to treatment plan optimization in photon radiation therapy.

    Science.gov (United States)

    Sánchez-Nieto, Beatriz; Romero-Expósito, Maite; Terrón, José A; Sánchez-Doblado, Francisco

    2017-10-01

    Biological treatment plan evaluation does not currently consider second cancer induction from peripheral doses associated to photon radiotherapy. The aim is to propose a methodology to characterize the therapeutic window by means of an integral radiobiological approach, which considers not only Tumour Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) but also Secondary Cancer Probability (SCP). Uncomplicated and Cancer-Free Control Probability (UCFCP) function has been proposed assuming a statistically uncorrelated response for tumour and normal tissues. The Poisson's and Lyman's models were chosen for TCP and NTCP calculations, respectively. SCP was modelled as the summation of risks associated to photon and neutron irradiation of radiosensitive organs. For the medium (>4Gy) and low dose regions, mechanistic and linear secondary cancer risks models were used, respectively. Two conformal and intensity-modulated prostate plans at 15MV (same prescription dose) were selected to illustrate the UCFCP features. UCFCP exhibits a bell-shaped behaviour with its maximum inside the therapeutic window. SCP values were not different for the plans analysed (∼2.4%) and agreed with published epidemiological results. Therefore, main differences in UCFCP came from differences in rectal NTCP (18% vs 9% for 3D-CRT and IMRT, respectively). According to UCFCP values, the evaluated IMRT plan ranked first. The level of SCP was found to be similar to that of NTCP complications which reinforces the importance of considering second cancer risks as part of the possible late sequelae due to treatment. Previous concerns about the effect of peripheral radiation, especially neutrons, in the induction of secondary cancers can be evaluated by quantifying the UCFCP. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  8. Intensity-modulated radiation therapy and xerostomia

    National Research Council Canada - National Science Library

    Chambers, Mark S; Weber, Randal S; Garden, Adam S

    2006-01-01

    Conformal radiation with intensity-modulated radiation therapy, IMRT, is a radiation technique that potentially can minimize the dose to salivary glands and thereby decrease the incidence of xerostomia...

  9. Late complications of radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Masaki, Norie [Osaka Prefectural Center for Adult Diseases (Japan)

    1998-03-01

    There are cases in which, although all traces of acute radiation complications seem to have disappeared, late complications may appear months or years to become apparent. Trauma, infection or chemotherapy may sometimes recall radiation damage and irreversible change. There were two cases of breast cancer that received an estimated skin dose in the 6000 cGy range followed by extirpation of the residual tumor. The one (12 y.o.) developed atrophy of the breast and severe teleangiectasis 18 years later radiotherapy. The other one (42 y.o.) developed severe skin necrosis twenty years later radiotherapy after administration of chemotherapy and received skin graft. A case (52 y.o.) of adenoidcystic carcinoma of the trachea received radiation therapy. The field included the thoracic spinal cord which received 6800 cGy. Two years and 8 months after radiation therapy she developed complete paraplegia and died 5 years later. A truly successful therapeutic outcome requires that the patient be alive, cured and free of significant treatment-related morbidity. As such, it is important to assess quality of life in long-term survivors of cancer treatment. (author)

  10. Development of local radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hoon; Lim, Sang Moo; Choi, Chang Woon; Chai, Jong Su; Kim, Eun Hee; Kim, Mi Sook; Yoo, Seong Yul; Cho, Chul Koo; Lee, Yong Sik; Lee, Hyun Moo

    1999-04-01

    The major limitations of radiation therapy for cancer are the low effectiveness of low LET and inevitable normal tissue damage. Boron Neutron Capture Therapy (BNCT) is a form of potent radiation therapy using Boron-10 having a high propensityof capturing theraml neutrons from nuclear reactor and reacting with a prompt nuclear reaction. Photodynamic therapy is a similiar treatment of modality to BNCT using tumor-seeking photosenistizer and LASER beam. If Boron-10 and photosensitizers are introduced selectively into tumor cells, it is theoretically possible to destroy the tumor and to spare the surrounding normal tissue. Therefore, BNCT and PDT will be new potent treatment modalities in the next century. In this project, we performed PDT in the patients with bladder cancers, oropharyngeal cancer, and skin cancers. Also we developed I-BPA, new porphyrin compounds, methods for estimation of radiobiological effect of neutron beam, and superficial animal brain tumor model. Furthermore, we prepared preclinical procedures for clinical application of BNCT, such as the macro- and microscopic dosimetry, obtaining thermal neutron flux from device used for fast neutron production in KCCH have been performed.

  11. Beam’s-eye-view dosimetrics (BEVD) guided rotational station parameter optimized radiation therapy (SPORT) planning based on reweighted total-variation minimization

    Science.gov (United States)

    Kim, Hojin; Li, Ruijiang; Lee, Rena; Xing, Lei

    2015-03-01

    Conventional VMAT optimizes aperture shapes and weights at uniformly sampled stations, which is a generalization of the concept of a control point. Recently, rotational station parameter optimized radiation therapy (SPORT) has been proposed to improve the plan quality by inserting beams to the regions that demand additional intensity modulations, thus formulating non-uniform beam sampling. This work presents a new rotational SPORT planning strategy based on reweighted total-variation (TV) minimization (min.), using beam’s-eye-view dosimetrics (BEVD) guided beam selection. The convex programming based reweighted TV min. assures the simplified fluence-map, which facilitates single-aperture selection at each station for single-arc delivery. For the rotational arc treatment planning and non-uniform beam angle setting, the mathematical model needs to be modified by additional penalty term describing the fluence-map similarity and by determination of appropriate angular weighting factors. The proposed algorithm with additional penalty term is capable of achieving more efficient and deliverable plans adaptive to the conventional VMAT and SPORT planning schemes by reducing the dose delivery time about 5 to 10 s in three clinical cases (one prostate and two head-and-neck (HN) cases with a single and multiple targets). The BEVD guided beam selection provides effective and yet easy calculating methodology to select angles for denser, non-uniform angular sampling in SPORT planning. Our BEVD guided SPORT treatment schemes improve the dose sparing to femoral heads in the prostate and brainstem, parotid glands and oral cavity in the two HN cases, where the mean dose reduction of those organs ranges from 0.5 to 2.5 Gy. Also, it increases the conformation number assessing the dose conformity to the target from 0.84, 0.75 and 0.74 to 0.86, 0.79 and 0.80 in the prostate and two HN cases, while preserving the delivery efficiency, relative to conventional single-arc VMAT plans.

  12. SIFT-based dense pixel tracking on 0.35 T cine-MR images acquired during image-guided radiation therapy with application to gating optimization

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, Thomas R., E-mail: tmazur@radonc.wustl.edu, E-mail: hli@radonc.wustl.edu; Fischer-Valuck, Benjamin W.; Wang, Yuhe; Yang, Deshan; Mutic, Sasa; Li, H. Harold, E-mail: tmazur@radonc.wustl.edu, E-mail: hli@radonc.wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 (United States)

    2016-01-15

    Purpose: To first demonstrate the viability of applying an image processing technique for tracking regions on low-contrast cine-MR images acquired during image-guided radiation therapy, and then outline a scheme that uses tracking data for optimizing gating results in a patient-specific manner. Methods: A first-generation MR-IGRT system—treating patients since January 2014—integrates a 0.35 T MR scanner into an annular gantry consisting of three independent Co-60 sources. Obtaining adequate frame rates for capturing relevant patient motion across large fields-of-view currently requires coarse in-plane spatial resolution. This study initially (1) investigate the feasibility of rapidly tracking dense pixel correspondences across single, sagittal plane images (with both moderate signal-to-noise and spatial resolution) using a matching objective for highly descriptive vectors called scale-invariant feature transform (SIFT) descriptors associated to all pixels that describe intensity gradients in local regions around each pixel. To more accurately track features, (2) harmonic analysis was then applied to all pixel trajectories within a region-of-interest across a short training period. In particular, the procedure adjusts the motion of outlying trajectories whose relative spectral power within a frequency bandwidth consistent with respiration (or another form of periodic motion) does not exceed a threshold value that is manually specified following the training period. To evaluate the tracking reliability after applying this correction, conventional metrics—including Dice similarity coefficients (DSCs), mean tracking errors (MTEs), and Hausdorff distances (HD)—were used to compare target segmentations obtained via tracking to manually delineated segmentations. Upon confirming the viability of this descriptor-based procedure for reliably tracking features, the study (3) outlines a scheme for optimizing gating parameters—including relative target position and a

  13. Optimizing the radiation therapy dose prescription for pediatric medulloblastoma: Minimizing the life years lost attributable to failure to control the disease and late complication risk

    DEFF Research Database (Denmark)

    Brodin, N. Patrik; Vogelius, Ivan R.; Bjork-Eriksson, Thomas

    2014-01-01

    Background. A mathematical framework is presented for simultaneously quantifying and evaluating the trade-off between tumor control and late complications for risk-based radiation therapy (RT) decision-support. To demonstrate this, we estimate life years lost (LYL) attributable to tumor recurrence......, late cardiac toxicity and secondary cancers for standard-risk pediatric medulloblastoma (MB) patients and compare the effect of dose re-distribution on a common scale. Methods. Total LYL were derived, based on the LYL attributable to radiation-induced late complications and the LYL from not controlling...... the primary disease. We compared the estimated LYL for three different treatments in 10 patients: 1) standard 3D conformal RT; 2) proton therapy; 3) risk-adaptive photon treatment lowering the dose to part of the craniospinal (CS) target volume situated close to critical risk organs. Results. Late toxicity...

  14. Intensity-Modulated Radiation Therapy (IMRT)

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Intensity-Modulated Radiation Therapy (IMRT) Intensity-modulated radiotherapy (IMRT) uses linear accelerators ... and after this procedure? What is Intensity-Modulated Radiation Therapy and how is it used? Intensity-modulated radiation ...

  15. Missed Radiation Therapy and Cancer Recurrence

    Science.gov (United States)

    Patients who miss radiation therapy sessions during cancer treatment have an increased risk of their disease returning, even if they eventually complete their course of radiation treatment, according to a new study.

  16. Mapping the literature of radiation therapy

    National Research Council Canada - National Science Library

    Delwiche, Frances A

    2013-01-01

    This study characterizes the literature of the radiation therapy profession, identifies the journals most frequently cited by authors writing in this discipline, and determines the level of coverage...

  17. Algorithms for optimizing drug therapy

    Directory of Open Access Journals (Sweden)

    Martin Lene

    2004-07-01

    Full Text Available Abstract Background Drug therapy has become increasingly efficient, with more drugs available for treatment of an ever-growing number of conditions. Yet, drug use is reported to be sub optimal in several aspects, such as dosage, patient's adherence and outcome of therapy. The aim of the current study was to investigate the possibility to optimize drug therapy using computer programs, available on the Internet. Methods One hundred and ten officially endorsed text documents, published between 1996 and 2004, containing guidelines for drug therapy in 246 disorders, were analyzed with regard to information about patient-, disease- and drug-related factors and relationships between these factors. This information was used to construct algorithms for identifying optimum treatment in each of the studied disorders. These algorithms were categorized in order to define as few models as possible that still could accommodate the identified factors and the relationships between them. The resulting program prototypes were implemented in HTML (user interface and JavaScript (program logic. Results Three types of algorithms were sufficient for the intended purpose. The simplest type is a list of factors, each of which implies that the particular patient should or should not receive treatment. This is adequate in situations where only one treatment exists. The second type, a more elaborate model, is required when treatment can by provided using drugs from different pharmacological classes and the selection of drug class is dependent on patient characteristics. An easily implemented set of if-then statements was able to manage the identified information in such instances. The third type was needed in the few situations where the selection and dosage of drugs were depending on the degree to which one or more patient-specific factors were present. In these cases the implementation of an established decision model based on fuzzy sets was required. Computer programs

  18. Melioidosis: reactivation during radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jegasothy, B.V.; Goslen, J.B.; Salvatore, M.A.

    1980-05-01

    Melioidosis is caused by Pseudomonas pseudomallei, a gram-negative, motile bacillus which is a naturally occurring soil saprophyte. The organism is endemic in Southeast Asia, the Philippines, Australia, and parts of Central and South America. Most human disease occurs from infection acquired in these countries. Infection with P pseudomallei may produce no apparent clinical disease. Acute pneumonitis or septicemia may result from inhalation of the organism, and inoculation into sites of trauma may cause localized skin abscesses, or the disease may remain latent and be reactivated months or years later by trauma, burns, or pneumococcal pneumonia, diabetic ketoacidosis, influenza, or bronchogenic carcinoma. The last is probably the commonest form of melioidosis seen in the United States. We present the first case of reactivation of melioidosis after radiation therapy for carcinoma of the lung, again emphasizing the need to consider melioidosis in a septic patient with a history of travel, especially to Southeast Asia.

  19. Exposure Risks Among Children Undergoing Radiation Therapy: Considerations in the Era of Image Guided Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Clayton B. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Thompson, Holly M. [Department of Diagnostic Radiology, University of California Davis Medical Center, Sacramento, California (United States); Benedict, Stanley H. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Seibert, J. Anthony [Department of Diagnostic Radiology, University of California Davis Medical Center, Sacramento, California (United States); Wong, Kenneth [Department of Radiation Oncology, University of California Los Angeles Jonsson Comprehensive Cancer Center, University of California David Geffen School of Medicine, Los Angeles, California (United States); Vaughan, Andrew T. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Chen, Allen M., E-mail: allenmchen@yahoo.com [Department of Radiation Oncology, University of California Los Angeles Jonsson Comprehensive Cancer Center, University of California David Geffen School of Medicine, Los Angeles, California (United States)

    2016-04-01

    Recent improvements in toxicity profiles of pediatric oncology patients are attributable, in part, to advances in the field of radiation oncology such as intensity modulated radiation (IMRT) and proton therapy (IMPT). While IMRT and IMPT deliver highly conformal dose to targeted volumes, they commonly demand the addition of 2- or 3-dimensional imaging for precise positioning—a technique known as image guided radiation therapy (IGRT). In this manuscript we address strategies to further minimize exposure risk in children by reducing effective IGRT dose. Portal X rays and cone beam computed tomography (CBCT) are commonly used to verify patient position during IGRT and, because their relative radiation exposure is far less than the radiation absorbed from therapeutic treatment beams, their sometimes significant contribution to cumulative risk can be easily overlooked. Optimizing the conformality of IMRT/IMPT while simultaneously ignoring IGRT dose may result in organs at risk being exposed to a greater proportion of radiation from IGRT than from therapeutic beams. Over a treatment course, cumulative central-axis CBCT effective dose can approach or supersede the amount of radiation absorbed from a single treatment fraction, a theoretical increase of 3% to 5% in mutagenic risk. In select scenarios, this may result in the underprediction of acute and late toxicity risk (such as azoospermia, ovarian dysfunction, or increased lifetime mutagenic risk) in radiation-sensitive organs and patients. Although dependent on variables such as patient age, gender, weight, body habitus, anatomic location, and dose-toxicity thresholds, modifying IGRT use and acquisition parameters such as frequency, imaging modality, beam energy, current, voltage, rotational degree, collimation, field size, reconstruction algorithm, and documentation can reduce exposure, avoid unnecessary toxicity, and achieve doses as low as reasonably achievable, promoting a culture and practice of “gentle IGRT.”.

  20. WE-AB-BRA-09: Sensitivity of Plan Re-Optimization to Errors in Deformable Image Registration in Online Adaptive Image-Guided Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    McClain, B; Olsen, J; Green, O; Yang, D; Santanam, L; Olsen, L; Zhao, T; Rodriguez, V; Wooten, H; Mutic, S; Kashani, R [Washington University School of Medicine, St. Louis, Missouri (United States); Victoria, J; Dempsey, J [ViewRay Incorporated, Oakwood Village, OH (United States)

    2015-06-15

    Purpose: Online adaptive therapy (ART) relies on auto-contouring using deformable image registration (DIR). DIR’s inherent uncertainties require user intervention and manual edits while the patient is on the table. We investigated the dosimetric impact of DIR errors on the quality of re-optimized plans, and used the findings to establish regions for focusing manual edits to where DIR errors can Result in clinically relevant dose differences. Methods: Our clinical implementation of online adaptive MR-IGRT involves using DIR to transfer contours from CT to daily MR, followed by a physicians’ edits. The plan is then re-optimized to meet the organs at risk (OARs) constraints. Re-optimized abdomen and pelvis plans generated based on physician edited OARs were selected as the baseline for evaluation. Plans were then re-optimized on auto-deformed contours with manual edits limited to pre-defined uniform rings (0 to 5cm) around the PTV. A 0cm ring indicates that the auto-deformed OARs were used without editing. The magnitude of the variations caused by the non-deterministic optimizer was quantified by repeat re-optimizations on the same geometry to determine the mean and standard deviation (STD). For each re-optimized plan, various volumetric parameters for the PTV, the OARs were extracted along with DVH and isodose evaluation. A plan was deemed acceptable if the variation from the baseline plan was within one STD. Results: Initial results show that for abdomen and pancreas cases, a minimum of 5cm margin around the PTV is required for contour corrections, while for pelvic and liver cases a 2–3 cm margin is sufficient. Conclusion: Focusing manual contour edits to regions of dosimetric relevance can reduce contouring time in the online ART process while maintaining a clinically comparable plan. Future work will further refine the contouring region by evaluating the path along the beams, dose gradients near the target and OAR dose metrics.

  1. Modern Radiation Therapy for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Specht, Lena; Yahalom, Joachim; Illidge, Tim

    2014-01-01

    Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced...... on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy......, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom...

  2. [Radiation therapy of locally advanced prostate cancer].

    Science.gov (United States)

    Schmidt-Hegemann, N-S; Li, M; Eze, C; Belka, C; Ganswindt, U

    2017-11-01

    The risk classification for localized prostate cancer is based on the groups "low", "intermediate", and "high-risk" prostate cancer. Following this established risk group definition, locally advanced prostate cancer (cT3/4N0M0) has to be classified as "high-risk" prostate cancer. Radical prostatectomy or high-dose radiotherapy, which is combined with androgen deprivation, are the only curative standard treatments for locally advanced prostate cancer. Particularly adequate radiation doses, modern radiotherapy techniques like IMRT/IGRT, as well as long-term androgen suppression are essential for an optimal treatment outcome. In combination with definitive radiotherapy, androgen deprivation therapy should be started neoadjuvant/simultaneous to radiotherapy and is recommended to be continued after radiotherapy. Previous data suggest that 2‑year long-term androgen deprivation in this setting may not be inferior to 3‑year long-term androgen deprivation in high-risk patients. An additional radiation therapy of the lymphatic pathways in men with cN0 locally advanced/high-risk prostate cancer is still a matter of research. Ongoing trials may define selected subgroups with a suggested benefit at its best.

  3. Radiation Dose Optimization For Critical Organs

    Science.gov (United States)

    Khodadadegan, Yasaman

    Ionizing radiation used in the patient diagnosis or therapy has negative effects on the patient body in short term and long term depending on the amount of exposure. More than 700,000 examinations are everyday performed on Interventional Radiology modalities, however; there is no patient-centric information available to the patient or the Quality Assurance for the amount of organ dose received. In this study, we are exploring the methodologies to systematically reduce the absorbed radiation dose in the Fluoroscopically Guided Interventional Radiology procedures. In the first part of this study, we developed a mathematical model which determines a set of geometry settings for the equipment and a level for the energy during a patient exam. The goal is to minimize the amount of absorbed dose in the critical organs while maintaining image quality required for the diagnosis. The model is a large-scale mixed integer program. We performed polyhedral analysis and derived several sets of strong inequalities to improve the computational speed and quality of the solution. Results present the amount of absorbed dose in the critical organ can be reduced up to 99% for a specific set of angles. In the second part, we apply an approximate gradient method to simultaneously optimize angle and table location while minimizing dose in the critical organs with respect to the image quality. In each iteration, we solve a sub-problem as a MIP to determine the radiation field size and corresponding X-ray tube energy. In the computational experiments, results show further reduction (up to 80%) of the absorbed dose in compare with previous method. Last, there are uncertainties in the medical procedures resulting imprecision of the absorbed dose. We propose a robust formulation to hedge from the worst case absorbed dose while ensuring feasibility. In this part, we investigate a robust approach for the organ motions within a radiology procedure. We minimize the absorbed dose for the critical

  4. Modern radiation therapy for primary cutaneous lymphomas

    DEFF Research Database (Denmark)

    Specht, Lena; Dabaja, Bouthaina; Illidge, Tim

    2015-01-01

    Primary cutaneous lymphomas are a heterogeneous group of diseases. They often remain localized, and they generally have a more indolent course and a better prognosis than lymphomas in other locations. They are highly radiosensitive, and radiation therapy is an important part of the treatment......, either as the sole treatment or as part of a multimodality approach. Radiation therapy of primary cutaneous lymphomas requires the use of special techniques that form the focus of these guidelines. The International Lymphoma Radiation Oncology Group has developed these guidelines after multinational...... meetings and analysis of available evidence. The guidelines represent an agreed consensus view of the International Lymphoma Radiation Oncology Group steering committee on the use of radiation therapy in primary cutaneous lymphomas in the modern era....

  5. Preoperative breast radiation therapy: Indications and perspectives

    DEFF Research Database (Denmark)

    Lightowlers, S V; Boersma, L J; Fourquet, A

    2017-01-01

    Preoperative breast radiation therapy (RT) is not a new concept, but older studies failed to change practice. More recently, there has been interest in revisiting preoperative RT using modern techniques. This current perspective discusses the indications, summarises the published literature...

  6. Partial breast radiation therapy - external beam

    Science.gov (United States)

    ... 11, 2016. www.cancer.gov/types/breast/hp/breast-treatment-pdq . Accessed September 13, 2016. National Cancer Institute. Radiation therapy and you: support for people who have cancer. Cancer.gov Web ...

  7. WE-AB-204-04: Feature Selection and Clustering Optimization for Pseudo-CT Generation in MR-Based Attenuation Correction and Radiation Therapy Planning

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, J; Su, K [Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio (United States); Department of Radiology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio (United States); Hu, L; Traughber, M [Philips Healthcare, Cleveland, Ohio (United States); Pereira, G; Traughber, B [Department of Radiation Oncology, University Hospitals Seidman Cancer Center, Case Western Reserve University, Cleveland, Ohio (United States); Herrmann, K [Department of Radiology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio (United States); Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio (United States); Muzic, R [Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio (United States); Department of Radiology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio (United States); Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH (United States)

    2015-06-15

    Purpose: Accurate and robust photon attenuation derived from MR is essential for PET/MR and MR-based radiation treatment planning applications. Although the fuzzy C-means (FCM) algorithm has been applied for pseudo-CT generation, the input feature combination and the number of clusters have not been optimized. This study aims to optimize both for clinically practical pseudo-CT generation. Methods: Nine volunteers were recruited. A 190-second, single-acquisition UTE-mDixon with 25% (angular) sampling and 3D radial readout was performed to acquire three primitive MR features at TEs of 0.1, 1.5, and 2.8 ms: the free-induction-decay (FID), the first and the second echo images. Three derived images, Dixon-fat and Dixon-water generated by two-point Dixon water/fat separation, and R2* (1/T2*) map, were also created. To identify informative inputs for generating a pseudo-CT image volume, all 63 combinations, choosing one to six of the feature images, were used as inputs to FCM for pseudo-CT generation. Further, the number of clusters was varied from four to seven to find the optimal approach. Mean prediction deviation (MPD), mean absolute prediction deviation (MAPD), and correlation coefficient (R) of different combinations were compared for feature selection. Results: Among the 63 feature combinations, the four that resulted in the best MAPD and R were further compared along with the set containing all six features. The results suggested that R2* and Dixon-water are the most informative features. Further, including FID also improved the performance of pseudo-CT generation. Consequently, the set containing FID, Dixon-water, and R2* resulted in the most accurate, robust pseudo-CT when the number of cluster equals to five (5C). The clusters were interpreted as air, fat, bone, brain, and fluid. The six-cluster Result additionally included bone marrow. Conclusion: The results suggested that FID, Dixon-water, R2* are the most important features. The findings can be used to

  8. Radiation therapy services in South Africa

    African Journals Online (AJOL)

    mum electron energy capacity greater than 10 MEV. Nine machines have a maximum photon energy capa- city below 10 MEV (Table I). A cyclotron-based 66. MEV neutron therapy machine used as a national faci- lity is based in the Cape. TABLE I. Megavoltage radiation therapy units in South Africa. Photon. Electron.

  9. Radiation therapy. Recent advances and nursing implications.

    Science.gov (United States)

    Strohl, R A

    1990-06-01

    Radiation therapy is one of the oldest treatments available for cancer management. Since the discovery of x-rays and radioactivity in the 1890s, patients have been treated with radiation. Advances in equipment and in the understanding of radiobiology permit delivery of effective doses of radiation to tumors while minimizing normal tissue damage. Recent advances in radiation have expanded the scope of treatment. Large-field, large-dose radiation, such as half-body treatment, permits treatment of metastatic disease in an effective and well-tolerated manner in patients too ill to travel for therapy. Total skin electron therapy has been successful in managing extensive skin disease. Hyperfractionated treatment is an experimental approach that attempts to achieve better tumor control by treating with two fractions per day. Intraoperative radiation is a conceptually sound but logistically cumbersome plan in which treatment is given in a single fraction at the time of surgery. Its full potential may be realized when the technical difficulties of administration can be overcome. Brachytherapy is the use of radioactive sources implanted directly into the tumor or in a cavity in proximity to the tumor. Techniques have improved in both surgery and radiation, which allow previously inaccessible sites such as the brain to be implanted. Early-stage breast cancer has been effectively managed with lumpectomy followed by radiation. Hyperthermia is the use of heat in conjunction with radiation. Heat has been found to enhance the effect of radiation and limit the repair of radiation damage. The properties of heat cause it to be more damaging to tumor cells than to normal ones. The ability to sensitize cancer cells to radiation and protect normal cells from radiation has been an ongoing research objective. Clinical trials are in progress to isolate effective, easily administered, and nontoxic compounds. The nurse caring for the patient receiving radiation must have an understanding of

  10. Radiation therapy for metastatic spinal tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kida, Akio; Fukuda, Haruyuki [Osaka City Univ. (Japan). Medical School; Taniguchi, Shuji; Sakai, Kazuaki

    2000-02-01

    The results of radiation therapy for metastatic spinal tumors were evaluated in terms of pain relief, improvement of neurological impairment, and survival. Between 1986 and 1995, 52 symptomatic patients with metastatic spinal tumors treated with radiation therapy were evaluated. The patients all received irradiation of megavoltage energy. Therapeutic efficacy was evaluated in terms of pain relief and improvement of neurological impairment. Pain relief was observed in 29 (61.7%) of 47 patients with pain. Therapy was effective for 17 (70.8%) of 24 patients without neurological impairment, and efficacy was detected in 12 (52.2%) of 23 patients with neurological impairment. Improvement of neurological symptoms was obtained in seven (25.0%) of 28 patients with neurological impairment. Radiation therapy was effective for pain relief in patients with metastatic spinal tumors. In patients with neurological impairment, less pain relief was observed than in those without impairment. Improvement of neurological impairment was restricted, but radiation therapy was thought to be effective in some cases in the early stage of neurological deterioration. Radiation therapy for metastatic spinal tumors contraindicated for surgery was considered effective for improvement of patients' activities of daily living. (author)

  11. Radiation Therapy and You: Support for People with Cancer

    Science.gov (United States)

    ... Terms Blogs and Newsletters Health Communications Publications Reports Radiation Therapy and You: Support for People With Cancer ... Copy This booklet covers: Questions and Answers About Radiation Therapy. Answers common questions, such as what radiation ...

  12. 42 CFR 410.35 - X-ray therapy and other radiation therapy services: Scope.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false X-ray therapy and other radiation therapy services... Other Health Services § 410.35 X-ray therapy and other radiation therapy services: Scope. Medicare Part B pays for X-ray therapy and other radiation therapy services, including radium therapy and...

  13. [Laser radiations in medical therapy].

    Science.gov (United States)

    Richand, P; Boulnois, J L

    1983-06-30

    The therapeutic effects of various types of laser beams and the various techniques employed are studied. Clinical and experimental research has shown that Helio-Neon laser beams are most effective as biological stimulants and in reducing inflammation. For this reasons they are best used in dermatological surgery cases (varicose ulcers, decubital and surgical wounds, keloid scars, etc.). Infrared diode laser beams have been shown to be highly effective painkillers especially in painful pathologies like postherpetic neuritis. The various applications of laser therapy in acupuncture, the treatment of reflex dermatologia and optic fibre endocavital therapy are presented. The neurophysiological bases of this therapy are also briefly described.

  14. Clinical applications of advanced rotational radiation therapy

    Science.gov (United States)

    Nalichowski, Adrian

    Purpose: With a fast adoption of emerging technologies, it is critical to fully test and understand its limits and capabilities. In this work we investigate new graphic processing unit (GPU) based treatment planning algorithm and its applications in helical tomotherapy dose delivery. We explore the limits of the system by applying it to challenging clinical cases of total marrow irradiation (TMI) and stereotactic radiosurgery (SRS). We also analyze the feasibility of alternative fractionation schemes for total body irradiation (TBI) and TMI based on reported historical data on lung dose and interstitial pneumonitis (IP) incidence rates. Methods and Materials: An anthropomorphic phantom was used to create TMI plans using the new GPU based treatment planning system and the existing CPU cluster based system. Optimization parameters were selected based on clinically used values for field width, modulation factor and pitch. Treatment plans were also created on Eclipse treatment planning system (Varian Medical Systems Inc, Palo Alto, CA) using volumetric modulated arc therapy (VMAT) for dose delivery on IX treatment unit. A retrospective review was performed of 42 publications that reported IP rates along with lung dose, fractionation regimen, dose rate and chemotherapy. The analysis consisted of nearly thirty two hundred patients and 34 unique radiation regimens. Multivariate logistic regression was performed to determine parameters associated with IP and establish does response function. Results: The results showed very good dosimetric agreement between the GPU and CPU calculated plans. The results from SBRT study show that GPU planning system can maintain 90% target coverage while meeting all the constraints of RTOG 0631 protocol. Beam on time for Tomotherapy and flattening filter free RapidArc was much faster than for Vero or Cyberknife. Retrospective data analysis showed that lung dose and Cyclophosphomide (Cy) are both predictors of IP in TBI/TMI treatments. The

  15. Radiation therapy for the solitary plasmacytoma

    Directory of Open Access Journals (Sweden)

    Esengül Koçak

    2010-06-01

    Full Text Available Plasma-cell neoplasms are classically categorized into four groups as: multiple myeloma (MM, plasma-cell leukemias, solitary plasmacytomas (SP of the bone (SPB, and extramedullary plasmacytomas (EMP. These tumors may be described as localized or diffuse in presentation. Localized plasma-cell neoplasms are rare, and include SP of the skeletal system, accounting for 2-5% of all plasma-cell neoplasms, and EMP of soft tissue, accounting for approximately 3% of all such neoplasms. SP is defined as a solitary mass of neoplastic plasma cells either in the bone marrow or in various soft tissue sites. There appears to be a continuum in which SP often progresses to MM. The main treatment modality for SP is radiation therapy (RT. However, there are no conclusive data in the literature on the optimal RT dose for SP. This review describes the interrelationship of plasma-cell neoplasms, and attempts to determine the minimal RT dose required to obtain local control.

  16. Cancer and electromagnetic radiation therapy: Quo Vadis?

    CERN Document Server

    Makropoulou, Mersini

    2016-01-01

    In oncology, treating cancer with a beam of photons is a well established therapeutic technique, developed over 100 years, and today over 50% of cancer patients will undergo traditional X-ray radiotherapy. However, ionizing radiation therapy is not the only option, as the high-energy photons delivering their cell-killing radiation energy into cancerous tumor can lead to significant damage to healthy tissues surrounding the tumor, located throughout the beam's path. Therefore, in nowadays, advances in ionizing radiation therapy are competitive to non-ionizing ones, as for example the laser light based therapy, resulting in a synergism that has revolutionized medicine. The use of non-invasive or minimally invasive (e.g. through flexible endoscopes) therapeutic procedures in the management of patients represents a very interesting treatment option. Moreover, as the major breakthrough in cancer management is the individualized patient treatment, new biophotonic techniques, e.g. photo-activated drug carriers, help...

  17. Monte Carlo techniques in radiation therapy

    CERN Document Server

    Verhaegen, Frank

    2013-01-01

    Modern cancer treatment relies on Monte Carlo simulations to help radiotherapists and clinical physicists better understand and compute radiation dose from imaging devices as well as exploit four-dimensional imaging data. With Monte Carlo-based treatment planning tools now available from commercial vendors, a complete transition to Monte Carlo-based dose calculation methods in radiotherapy could likely take place in the next decade. Monte Carlo Techniques in Radiation Therapy explores the use of Monte Carlo methods for modeling various features of internal and external radiation sources, including light ion beams. The book-the first of its kind-addresses applications of the Monte Carlo particle transport simulation technique in radiation therapy, mainly focusing on external beam radiotherapy and brachytherapy. It presents the mathematical and technical aspects of the methods in particle transport simulations. The book also discusses the modeling of medical linacs and other irradiation devices; issues specific...

  18. Advanced Small Animal Conformal Radiation Therapy Device.

    Science.gov (United States)

    Sharma, Sunil; Narayanasamy, Ganesh; Przybyla, Beata; Webber, Jessica; Boerma, Marjan; Clarkson, Richard; Moros, Eduardo G; Corry, Peter M; Griffin, Robert J

    2017-02-01

    We have developed a small animal conformal radiation therapy device that provides a degree of geometrical/anatomical targeting comparable to what is achievable in a commercial animal irradiator. small animal conformal radiation therapy device is capable of producing precise and accurate conformal delivery of radiation to target as well as for imaging small animals. The small animal conformal radiation therapy device uses an X-ray tube, a robotic animal position system, and a digital imager. The system is in a steel enclosure with adequate lead shielding following National Council on Radiation Protection and Measurements 49 guidelines and verified with Geiger-Mueller survey meter. The X-ray source is calibrated following AAPM TG-61 specifications and mounted at 101.6 cm from the floor, which is a primary barrier. The X-ray tube is mounted on a custom-made "gantry" and has a special collimating assembly system that allows field size between 0.5 mm and 20 cm at isocenter. Three-dimensional imaging can be performed to aid target localization using the same X-ray source at custom settings and an in-house reconstruction software. The small animal conformal radiation therapy device thus provides an excellent integrated system to promote translational research in radiation oncology in an academic laboratory. The purpose of this article is to review shielding and dosimetric measurement and highlight a few successful studies that have been performed to date with our system. In addition, an example of new data from an in vivo rat model of breast cancer is presented in which spatially fractionated radiation alone and in combination with thermal ablation was applied and the therapeutic benefit examined.

  19. Breast Reconstruction and Radiation Therapy: An Update.

    Science.gov (United States)

    Nelson, Jonas A; Disa, Joseph J

    2017-11-01

    With the indications for radiation therapy in the treatment of breast cancer continuing to expand, many patients present for reconstruction having previously had radiation or having a high likelihood of requiring radiation following mastectomy. Both situations are challenging for the plastic surgeon, with different variables impacting the surgical outcome. To date, multiple studies have been performed examining prosthetic and autologous reconstruction in this setting. The purpose of this article was to provide a general platform for understanding the literature as it relates to reconstruction and radiation through an examination of recent systematic reviews and relevant recent publications. We examined this with a focus on the timing of the radiation, and within this context, examined the data from the traditional surgical outcomes standpoint as well as from a patient-reported outcomes perspective. The data provided within will aid in patient counseling and the informed consent process.

  20. 21 CFR 892.5300 - Medical neutron radiation therapy system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical neutron radiation therapy system. 892.5300... therapy system. (a) Identification. A medical neutron radiation therapy system is a device intended to generate high-energy neutrons for radiation therapy. This generic type of device may include signal...

  1. Motion management in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bert, Christoph [GSI, Helmholtzzentrum fuer Schwerionenforschung, Abteilung Biophysik, Darmstadt (Germany)

    2009-07-01

    Radiotherapy of tumors that move during irradiation requires dedicated means to ensure target coverage despite the motion influence. Motion can occur inter-fractionally (e.g. position of the prostate) or intra-fractionally; the most dominant reason for intra-fractional motion is respiration. The standard procedure to reduce the influence of target motion is the use of margins encompassing the clinical target volume (CTV) to form a planning target volume (PTV) that covers all uncertainties. This approach ensures CTV coverage for most treatment modalities but results in therapeutic dose to normal tissue. With the opportunities given by improved imaging techniques such as time-resolved computed tomography (CT) or (cone-beam) CT in treatment position as well as motion mitigation techniques such as gating or tracking the dosimetric influence of target motion could be reduced. Especially for conformal techniques such as intensity modulated radiotherapy (IMRT) or particle therapy only advanced motion mitigation techniques and/or adaptive therapy concepts lead to preservation of the target conformation established for stationary targets in treatments of moving targets. In the scope of the talk an introduction to motion management is given with an emphasis on application in scanned particle beam therapy.

  2. Radiation Therapy for Carcinoma of the Oropharynx

    Energy Technology Data Exchange (ETDEWEB)

    Park, In Kyu; Kim, Jae Choel [Kyungpook National University College of Medicine, Taegu (Korea, Republic of)

    1996-06-15

    Purpose : A retrospective analysis for patients with oropharyngeal carcinoma who were treated with radiation was performed to assess the results of treatment and patterns of failure, and to identify the factors that might influence survival. Methods and Materials : From March 1985 through June 1993, 53 patients with oropharyngeal carcinoma were treated with either radiation therapy alone or combination of neoadjuvant chemotherapy and radiation therapy at the Department of Radiation Oncology, Kyungpook National University Hospital. Patients' ages ranged from 31 to 73 years with a median age of 54 years. There were 47 men and 6 women. Forty-two patients (79.2%) had squamous cell carcinoma, 10 patients (18.9%) had undifferentiated carcinoma and 1 patient (1.9%) had adenoid cystic carcinoma. There were 2 patients with stage I 12 patients with stage II, 12 patients with stage III and 27 patients with stage IV. According to the TNM classification, patients were distributed as follows: T1 7, T2 2, T3 10, T4 7, TX 1, and N0 17, N1 13, N2 21, N3 2. The primary tumor sites were tonsillar region in 36 patients (67.9%) base of the tongue in 12 patients (22.6%), and soft palate in 5 patients (9.4%). Twenty-five patients were treated with radiation therapy alone and twenty-eight patients were treated with one to three courses of chemotherapy followed by radiation therapy. Chemotherapeutic regimens used were either CF (cisplatin and 5-fluorouracil) or CVB (cisplatin, vincristine and bleomycin), Radiation therapy was delivered 180-200 cGy daily,five times a week using 6 MV X-ray with or without 8-10 MeV electron beams. A tumor dose ranged from 4500 cGy to 7740 cGy with a median dose of 7100 cGy. The follow-up time ranged from 4months to 99 months with a median of 21 months. Results : Thrity-seven patients (69.8%) achieved a CR (complete response) and PR (partial response) in 16 patients (30.2%) after radiation therapy. The overall survival rates were 47% at 2 years and 42% at

  3. PET/CT in Radiation Therapy Planning

    DEFF Research Database (Denmark)

    Specht, Lena; Berthelsen, Anne Kiil

    2018-01-01

    Radiation therapy (RT) is an important component of the management of lymphoma patients. Most lymphomas are metabolically active and accumulate 18F-fluorodeoxyglucose (FDG). Positron emission tomography with computer tomography (PET/CT) imaging using FDG is used routinely in staging and treatment...

  4. Process of Coping with Radiation Therapy.

    Science.gov (United States)

    Johnson, Jean E.; And Others

    1989-01-01

    Evaluated ability of self-regulation and emotional-drive theories to explain effects of informational intervention entailing objective descriptions of experience on outcomes of coping with radiation therapy among 84 men with prostate cancer. Consistent with self-regulation theory, similarity between expectations and experience and degree of…

  5. Stereotactic body radiation therapy delivery validation

    Science.gov (United States)

    Olding, T.; Garcia, L.; Alexander, K.; Schreiner, L. J.; Joshi, C.

    2013-06-01

    This work describes the use of a motion phantom and 1D, 2D, and 3D ion chamber, EBT3 film, electronic portal imaging device (EPID) and FXG gel measurements for dosimetric validation of a stereotactic ablative radiation therapy (SBRT) technique in our clinic. Results show good agreement between the measurements and calculated treatment plan dose.

  6. Stereotactic radiation therapy for large vestibular schwannomas

    NARCIS (Netherlands)

    Mandl, Ellen S.; Meijer, Otto W. M.; Slotman, Ben J.; Vandertop, W. Peter; Peerdeman, Saskia M.

    2010-01-01

    Background and purpose: To evaluate the morbidity and tumor-control rate in the treatment of large vestibular schwannomas (VS) after stereotactic radiation therapy in our institution. Material and methods: Twenty-five consecutive patients (17 men, 8 women) with large VS (diameter 3.0 cm or larger),

  7. A retrospective planning analysis comparing intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) using two optimization algorithms for the treatment of early-stage prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Elith, Craig A [British Columbia Cancer Agency, Fraser Valley Centre, Surrey, BC (Canada); School of Health Sciences, University of Newcastle, Newcastle, NSW (Australia); Dempsey, Shane E; Warren-Forward, Helen M [School of Health Sciences, University of Newcastle, Newcastle, NSW (Australia); British Columbia Cancer Agency, Fraser Valley Centre, Surrey, BC (Canada)

    2013-09-15

    The primary aim of this study is to compare intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) for the radical treatment of prostate cancer using version 10.0 (v10.0) of Varian Medical Systems, RapidArc radiation oncology system. Particular focus was placed on plan quality and the implications on departmental resources. The secondary objective was to compare the results in v10.0 to the preceding version 8.6 (v8.6). Twenty prostate cancer cases were retrospectively planned using v10.0 of Varian's Eclipse and RapidArc software. Three planning techniques were performed: a 5-field IMRT, VMAT using one arc (VMAT-1A), and VMAT with two arcs (VMAT-2A). Plan quality was assessed by examining homogeneity, conformity, the number of monitor units (MUs) utilized, and dose to the organs at risk (OAR). Resource implications were assessed by examining planning and treatment times. The results obtained using v10.0 were also compared to those previously reported by our group for v8.6. In v10.0, each technique was able to produce a dose distribution that achieved the departmental planning guidelines. The IMRT plans were produced faster than VMAT plans and displayed improved homogeneity. The VMAT plans provided better conformity to the target volume, improved dose to the OAR, and required fewer MUs. Treatments using VMAT-1A were significantly faster than both IMRT and VMAT-2A. Comparison between versions 8.6 and 10.0 revealed that in the newer version, VMAT planning was significantly faster and the quality of the VMAT dose distributions produced were of a better quality. VMAT (v10.0) using one or two arcs provides an acceptable alternative to IMRT for the treatment of prostate cancer. VMAT-1A has the greatest impact on reducing treatment time.

  8. [Radiation therapy in pancreatic cancer].

    Science.gov (United States)

    Chie, Eui Kyu

    2008-02-01

    Radiotherapy has been offered to patients with pancreatic cancer, either in the adjuvant or definitive setting. However, the role of radiotherapy in pancreatic cancer is increasingly doubted, especially after the introduction of gemcitabine to both domains. Although contradictory data exist, combined chemoradiotherapy improves both quantity and quality of life for patients with locally advanced tumors compared with radiotherapy alone or chemotherapy alone. Recently, induction chemotherapy strategy is being evaluated for better selection of patients for optimal benefit from consolidative chemoradiotherapy. Much controversy has been suggested concerning the role of adjuvant radiotherapy, but quality assurance for radiotherapy was not considered in the previously reported studies. Combined chemoradiotherapy in the adjuvant setting is still considered as a viable option. Current phase III randomized on-going studies will provide better answers on the role of radiotherapy in the treatment of pancreatic cancer.

  9. A dosimetric evaluation of volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy for the lower extremity soft tissue sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sol Min; Song, Seong Chan; Hyun, Sung Eun; Park, Heung Deuk; Lee, Jaegi; Kim, Young Suk; Kim, Gwi Eon [Dept. of Radiation Oncology, Jeju National University Hospital, Jeju (Korea, Republic of)

    2016-06-15

    A dosimetric evaluation of volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy for the lower extremity soft tissue sarcoma For the lower extremity soft tissue sarcoma, volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy were evaluated to compare these three treatment planning technique. The mean doses to the planning target volume and the femur were calculated to evaluate target coverage and the risk of bone fracture during radiation therapy. Volumetric modulated arc therapy can reduce the dose to the femur without compromising target coverage and reduce the treatment time compared with intensity modulated radiation therapy.

  10. Optimization of the image contrast in SPECT-CT bremsstrahlung imaging for Selective Internal Radiation Therapy of liver malignancies with Y-90 microspheres

    CERN Document Server

    Bonutti, Faustino; Magro, Giuseppe; Cecotti, Andrea; Della Schiava, Emanuele; Del Dò, Elena; Longo, Francesco; Herassi, Yassine; Bentayeb, Farida; Rossi, Marina; Ferretti, Guido; Geatti, Onelio; Padovani, Renato

    2015-01-01

    The quality of SPECT Bremsstrahlung images of patients treated with Y-90 is poor, mainly because of scattered radiation and collimator septa penetration. To minimize the latter effect, High Energy (HE) or Medium Energy (ME) collimators can be used. Scatter correction is not possible through the methods commonly used for the diagnostic radionuclides (Tc-99m, etc.) because the Bremsstrahlung radiation does not have distinct photopeaks, but a broad spectrum of energies ranging from zero to the maximum one detectable by the gamma-camera crystal is registered. Scatter radiation and collimator septa penetration affect the Contrast and the Contrast Recovery Coefficient (CRC) : our research focused on finding the best energy position for the acquisition window in order to maximize these parameters. To be guided in this finding, we first made a Monte Carlo (MC) simulation of a SPECT acquisition of a Y-90 cylindrical phantom and then we measured at different energies the Line Spread Function (LSF) of a linear Y-90 sour...

  11. Optimizing adherence to antiretroviral therapy.

    Science.gov (United States)

    Sahay, Seema; Reddy, K Srikanth; Dhayarkar, Sampada

    2011-12-01

    HIV has now become a manageable chronic disease. However, the treatment outcomes may get hampered by suboptimal adherence to ART. Adherence optimization is a concrete reality in the wake of 'universal access' and it is imperative to learn lessons from various studies and programmes. This review examines current literature on ART scale up, treatment outcomes of the large scale programmes and the role of adherence therein. Social, behavioural, biological and programme related factors arise in the context of ART adherence optimization. While emphasis is laid on adherence, retention of patients under the care umbrella emerges as a major challenge. An in-depth understanding of patients' health seeking behaviour and health care delivery system may be useful in improving adherence and retention of patients in care continuum and programme. A theoretical framework to address the barriers and facilitators has been articulated to identify problematic areas in order to intervene with specific strategies. Empirically tested objective adherence measurement tools and approaches to assess adherence in clinical/ programme settings are required. Strengthening of ART programmes would include appropriate policies for manpower and task sharing, integrating traditional health sector, innovations in counselling and community support. Implications for the use of theoretical model to guide research, clinical practice, community involvement and policy as part of a human rights approach to HIV disease is suggested.

  12. Comparison of particle-radiation-therapy modalities

    Energy Technology Data Exchange (ETDEWEB)

    Fairchild, R.G.; Bond, V.P.

    1981-01-01

    The characteristics of dose distribution, beam alignment, and radiobiological advantages accorded to high LET radiation were reviewed and compared for various particle beam radiotherapeutic modalities (neutron, Auger electrons, p, ..pi../sup -/, He, C, Ne, and Ar ions). Merit factors were evaluated on the basis of effective dose to tumor relative to normal tissue, linear energy transfer (LET), and dose localization, at depths of 1, 4, and 10 cm. In general, it was found that neutron capture therapy using an epithermal neutron beam provided the best merit factors available for depths up to 8 cm. The position of fast neutron therapy on the Merit Factor Tables was consistently lower than that of other particle modalities, and above only /sup 60/Co. The largest body of clinical data exists for fast neutron therapy; results are considered by some to be encouraging. It then follows that if benefits with fast neutron therapy are real, additional gains are within reach with other modalities.

  13. 21 CFR 892.5750 - Radionuclide radiation therapy system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide radiation therapy system. 892.5750... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5750 Radionuclide radiation therapy system. (a) Identification. A radionuclide radiation therapy system is a device intended to permit an...

  14. 21 CFR 892.5840 - Radiation therapy simulation system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiation therapy simulation system. 892.5840... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5840 Radiation therapy simulation system. (a) Identification. A radiation therapy simulation system is a fluoroscopic or radiographic x-ray...

  15. Aspects on the development of radiation therapy and radiation biology since the early work of Rolf Wideroee

    Energy Technology Data Exchange (ETDEWEB)

    Brahme, A. [Stockholm Univ. (Sweden). Dept. of Medical Radiation Physics

    1998-12-31

    Dr. Wideroee conceived his first idea on a `ray transformer` or betatron in 1922. During the 1950s and early 1960s Wideroee was extensively involved in the clinical developments of betatrons and he had a large number of patents on their chemical development. In the mid-1960 Wideroee took great interest in radiation biology, seeking to model the therapeutic properties and to better understand how to make the best use of radiation therapy beams. Many of Wideroee`s early publications contain the precursors of the rapid development of radiobiologically optimized treatment planning techniques that we are witnessing today. The recent developments, such as inverse treatment planning and optimization, biologically optimized therapy, modern dose delivery methods, fan- and pencil-beam therapy and scanning beam therapy are shortly reviewed.(orig./MG)

  16. Radiation Therapy in Elderly Skin Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hee [Keimyung University College of Medicine, Daegu (Korea, Republic of)

    2008-06-15

    To evaluate the long term results (local control, survival, failure, and complications) after radiation therapy for skin cancer in elderly patients. The study spanned from January 1990 to October 2002. Fifteen elderly patients with skin cancer were treated by radiotherapy at the Keimyung University Dongsan Medical Center. The age distribution of the patients surveyed was 72 to 95 years, with a median age of 78.8 years. The pathologic classification of the 15 patients included squamous cell carcinoma (10 patients), basal cell carcinoma (3 patients), verrucous carcinoma (1 patient) and skin adnexal origin carcinoma (1 patient). The most common tumor location was the head (13 patients). The mean tumor diameter was 4.9 cm (range 2 to 9 cm). The radiation dose was delivered via an electron beam of 6 to 15 MeV. The dose range was adjusted to the tumor diameter and depth of tumor invasion. The total radiation dose ranged from 50{approx}80 Gy (mean: 66 Gy) with a 2 Gy fractional dose prescribed to the 80% isodose line once a day and 5 times a week. One patient with lymph node metastasis was treated with six MV photon beams boosted with electron beams. The length of the follow-up periods ranged from 10 to 120 months with a median follow-up period of 48 months. The local control rates were 100% (15/15). In addition, the five year disease free survival rate (5YDFS) was 80% and twelve patients (80%) had no recurrence and skin cancer recurrence occurred in 3 patients (20%). Three patients have lived an average of 90 months (68{approx}120 months) without recurrence or metastasis. A total of 9 patients who died as a result of other causes had a mean survival time of 55.8 months after radiation therapy. No severe acute or chronic complications were observed after radiation therapy. Only minor complications including radiation dermatitis was treated with supportive care. The results suggest that radiation therapy is an effective and safe treatment method for the treatment of skin

  17. Targeted Radiation Therapy for Cancer Initiative

    Science.gov (United States)

    2017-11-01

    VA 22202- 4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing...Oncology Biology Physics. Contributors to this article are: Avinash R. Chaurasia, Kelly J. Sun, Christopher Premo, Timothy Brand , Brent Tinnel...salvage radiation therapy.” Poster was presented at the ASCO/ASTRO 2013 Genitourinary Cancers Symposium. • Chaurasia A, Sun K, Premo C, Brand T, Tinnel

  18. Arc binary intensity modulated radiation therapy (AB IMRT)

    Science.gov (United States)

    Yang, Jun

    The state of the art Intensity Modulate Radiation Therapy (IMRT) has been one of the most significant breakthroughs in the cancer treatment in the past 30 years. There are two types of IMRT systems. The first system is the binary-based tomotherapy, represented by the Peacock (Nomos Corp) and Tomo unit (TomoTherapy Inc.), adopting specific binary collimator leafs to deliver intensity modulated radiation fields in a serial or helical fashion. The other uses the conventional dynamic multileaf collimator (MLC) to deliver intensity modulated fields through a number of gantry positions. The proposed Arc Binary IMRT attempts to deliver Tomo-like IMRT with conventional dynamic MLC and combines the advantages of the two types of IMRT techniques: (1) maximizing the number of pencil beams for better dose optimization, (2) enabling conventional linear accelerator with dynamic MLC to deliver Tomo-like IMRT. In order to deliver IMRT with conventional dynamic MLC in a binary fashion, the slice-by-slice treatment with limited slice thickness has been proposed in the thesis to accommodate the limited MLC traveling speed. Instead of moving the patient to subsequent treatment slices, the proposed method offsets MLC to carry out the whole treatment, slice by slice sequentially, thus avoid patient position error. By denoting one arc pencil beam set as a gene, genetic algorithm (GA) is used as the searching engine for the dose optimization process. The selection of GA parameters is a crucial step and has been studied in depth so that the optimization process will converge with reasonable speed. Several hypothetical and clinical cases have been tested with the proposed IMRT method. The comparison of the dose distribution with other commercially available IMRT systems demonstrates the clear advantage of the new method. The proposed Arc Binary Intensity Modulated Radiation Therapy is not only theoretically sound but practically feasible. The implementation of this method would expand the

  19. Pirfenidone enhances the efficacy of combined radiation and sunitinib therapy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seo-Hyun; Nam, Jae-Kyung; Jang, Junho; Lee, Hae-June, E-mail: hjlee@kcch.re.kr; Lee, Yoon-Jin, E-mail: yjlee8@kcch.re.kr

    2015-06-26

    Radiotherapy is a widely used treatment for many tumors. Combination therapy using anti-angiogenic agents and radiation has shown promise; however, these combined therapies are reported to have many limitations in clinical trials. Here, we show that radiation transformed tumor endothelial cells (ECs) to fibroblasts, resulting in reduced vascular endothelial growth factor (VEGF) response and increased Snail1, Twist1, Type I collagen, and transforming growth factor (TGF)-β release. Irradiation of radioresistant Lewis lung carcinoma (LLC) tumors greater than 250 mm{sup 3} increased collagen levels, particularly in large tumor vessels. Furthermore, concomitant sunitinib therapy did not show a significant difference in tumor inhibition versus radiation alone. Thus, we evaluated multimodal therapy that combined pirfenidone, an inhibitor of TGF-induced collagen production, with radiation and sunitinib treatment. This trimodal therapy significantly reduced tumor growth, as compared to radiation alone. Immunohistochemical analysis revealed that radiation-induced collagen deposition and tumor microvessel density were significantly reduced with trimodal therapy, as compared to radiation alone. These data suggest that combined therapy using pirfenidone may modulate the radiation-altered tumor microenvironment, thereby enhancing the efficacy of radiation therapy and concurrent chemotherapy. - Highlights: • Radiation changes tumor endothelial cells to fibroblasts. • Radio-resistant tumors contain collagen deposits, especially in tumor vessels. • Pirfenidone enhances the efficacy of combined radiation and sunitinib therapy. • Pirfenidone reduces radiation-induced collagen deposits in tumors.

  20. Optimizing radiation exposure for CT localizer radiographs.

    Science.gov (United States)

    Bohrer, Evelyn; Schäfer, Stefan; Mäder, Ulf; Noël, Peter B; Krombach, Gabriele A; Fiebich, Martin

    2017-06-01

    The trend towards submillisievert CT scans leads to a higher dose fraction of localizer radiographs in CT examinations. The already existing technical capabilities make dose optimization of localizer radiographs worthwhile. Modern CT scanners apply automatic exposure control (AEC) based on attenuation data in such a localizer. Therefore not only this aspect but also the detectability of anatomical landmarks in the localizer for the desired CT scan range adjustment needs to be considered. The effective dose of a head, chest, and abdomen-pelvis localizer radiograph with standard factory settings and user-optimized settings was determined using Monte Carlo simulations. CT examinations of an anthropomorphic phantom were performed using multiple sets of acquisition parameters for the localizer radiograph and the AEC for the subsequent helical CT scan. Anatomical landmarks were defined to assess the image quality of the localizer. CTDIvol and effective mAs per slice of the helical CT scan were recorded to examine the impact of localizer settings on a helical CT scan. The dose of the localizer radiograph could be decreased by more than 90% while the image quality remained sufficient when selecting the lowest available settings (80kVp, 20mA, pa tube position). The tube position during localizer acquisition had a greater impact on the AEC than the reduction of tube voltage and tube current. Except for the use of a pa tube position, all changes of acquisition parameters for the localizer resulted in a decreased total radiation exposure. A dose reduction of CT localizer radiograph is necessary and possible. In the examined CT system there was no negative impact on the modulated helical CT scan when the lowest tube voltage and tube current were used for the localizer. Copyright © 2016. Published by Elsevier GmbH.

  1. Optimizing radiation exposure for CT localizer radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Bohrer, Evelyn; Maeder, Ulf; Fiebich, Martin [Univ. of Applied Sciences, Giessen (Germany). Inst. of Medical Physics and Radiation Protection-IMPS; Schaefer, Stefan; Krombach, Gabriele A. [Univ. Hospital Giessen (Germany). Dept. of Radiology; Noel, Peter B. [Technische Univ. Muenchen (Germany). Dept. of Diagnostic and Interventional Radiology

    2017-08-01

    The trend towards submillisievert CT scans leads to a higher dose fraction of localizer radiographs in CT examinations. The already existing technical capabilities make dose optimization of localizer radiographs worthwhile. Modern CT scanners apply automatic exposure control (AEC) based on attenuation data in such a localizer. Therefore not only this aspect but also the detectability of anatomical landmarks in the localizer for the desired CT scan range adjustment needs to be considered. The effective dose of a head, chest, and abdomen-pelvis localizer radiograph with standard factory settings and user-optimized settings was determined using Monte Carlo simulations. CT examinations of an anthropomorphic phantom were performed using multiple sets of acquisition parameters for the localizer radiograph and the AEC for the subsequent helical CT scan. Anatomical landmarks were defined to assess the image quality of the localizer. CTDI{sub vol} and effective mAs per slice of the helical CT scan were recorded to examine the impact of localizer settings on a helical CT scan. The dose of the localizer radiograph could be decreased by more than 90% while the image quality remained sufficient when selecting the lowest available settings (80 kVp, 20 mA, pa tube position). The tube position during localizer acquisition had a greater impact on the AEC than the reduction of tube voltage and tube current. Except for the use of a pa tube position, all changes of acquisition parameters for the localizer resulted in a decreased total radiation exposure. A dose reduction of CT localizer radiograph is necessary and possible. In the examined CT system there was no negative impact on the modulated helical CT scan when the lowest tube voltage and tube current were used for the localizer.

  2. EUD-based biological optimization for carbon ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brüningk, Sarah C., E-mail: sarah.brueningk@icr.ac.uk; Kamp, Florian; Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum rechts der Isar, Ismaninger Str. 22, München 81675, Germany and Physik-Department, Technische Universität München, James-Franck-Str. 1, Garching 85748 (Germany)

    2015-11-15

    Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

  3. Novel Silicon Devices for Radiation Therapy Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzi, Mara, E-mail: mara.bruzzi@unifi.it

    2016-02-11

    Modern radiotherapy techniques pose specific constraints in radiation-monitoring and dosimetry due to the occurrence of small radiation fields with high dose gradients, variation in space and time of the dose rate, variation in space and time of the beam energy spectrum. Novel devices coping with these strict conditions are needed. This paper reviews the most advanced technologies developed with silicon-based materials for clinical radiotherapy. Novel Si diodes as Pt-doped Si, epitaxial Si as well as thin devices have optimized performance, their response being independent of the accumulated dose, thus ensuring radiation tolerance and no need of recalibration. Monolithic devices based on segmented Si detectors can be easily tailored to optimize spatial resolution in the large active areas required in clinical radiotherapy. In particular, a monolithic device based on epitaxial p-type silicon, characterized by high spatial resolution and ability to directly measure temporal variations in dose modulation proved to be best viable solution for pre-treatment verifications in IMRT fields.

  4. Oral care of the cancer patient receiving radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Holtzhausen, T. (Medical Univ. of Southern Africa, Pretoria (South Africa). Dept. of Community Dentistry)

    1982-07-01

    Radiation therapy is frequently being used for the patient with oral cancer. The survival rate is increasing, due to more effective treatment technique. The question of whether any teeth should be extracted, the mode of therapy and the side effects of radiation like Xerostomia, caries, stomatitis, trismus and osteo-radionecrosis and also post radiation care are discussed.

  5. Stereotactic Body Radiation Therapy for Pancreatic Cancer.

    Science.gov (United States)

    Goodman, Karyn A

    2016-01-01

    The role of radiation therapy in the management of pancreatic cancer represents an area of some controversy. However, local disease progression remains a significant cause of morbidity and even mortality for patients with this disease. Stereotactic body radiotherapy (SBRT) is an emerging treatment option for pancreatic cancer, primarily for locally advanced (unresectable) disease as it can provide a therapeutic benefit with significant advantages for patients' quality of life over standard conventional chemoradiation. There may also be a role for SBRT as neoadjuvant therapy for patients with borderline resectable disease to allow conversion to resectability. The objective of this review is to present the data supporting SBRT in pancreatic cancer as well as the potential limitations and caveats of current studies.

  6. Mapping the literature of radiation therapy.

    Science.gov (United States)

    Delwiche, Frances A

    2013-04-01

    This study characterizes the literature of the radiation therapy profession, identifies the journals most frequently cited by authors writing in this discipline, and determines the level of coverage of these journals by major bibliographic indexes. Cited references from three discipline-specific source journals were analyzed according to the Mapping the Literature of Allied Health Project Protocol of the Nursing and Allied Health Resources Section of the Medical Library Association. Bradford's Law of Scattering was applied to all journal references to identify the most frequently cited journal titles. Journal references constituted 77.8% of the total, with books, government documents, Internet sites, and miscellaneous sources making up the remainder. Although a total of 908 journal titles were cited overall, approximately one-third of the journal citations came from just 11 journals. MEDLINE and Scopus provided the most comprehensive indexing of the journal titles in Zones 1 and 2. The source journals were indexed only by CINAHL and Scopus. The knowledgebase of radiation therapy draws heavily from the fields of oncology, radiology, medical physics, and nursing. Discipline-specific publications are not currently well covered by major indexing services, and those wishing to conduct comprehensive literature searches should search multiple resources.

  7. Mapping the literature of radiation therapy

    Science.gov (United States)

    Delwiche, Frances A.

    2013-01-01

    Objective: This study characterizes the literature of the radiation therapy profession, identifies the journals most frequently cited by authors writing in this discipline, and determines the level of coverage of these journals by major bibliographic indexes. Method: Cited references from three discipline-specific source journals were analyzed according to the Mapping the Literature of Allied Health Project Protocol of the Nursing and Allied Health Resources Section of the Medical Library Association. Bradford's Law of Scattering was applied to all journal references to identify the most frequently cited journal titles. Results: Journal references constituted 77.8% of the total, with books, government documents, Internet sites, and miscellaneous sources making up the remainder. Although a total of 908 journal titles were cited overall, approximately one-third of the journal citations came from just 11 journals. MEDLINE and Scopus provided the most comprehensive indexing of the journal titles in Zones 1 and 2. The source journals were indexed only by CINAHL and Scopus. Conclusion: The knowledgebase of radiation therapy draws heavily from the fields of oncology, radiology, medical physics, and nursing. Discipline-specific publications are not currently well covered by major indexing services, and those wishing to conduct comprehensive literature searches should search multiple resources. PMID:23646027

  8. Radiation therapy of the early glottic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Kazushige; Mitsuhashi, Norio; Ikeda, Hajime; Tamaki, Yoshio; Yamakawa, Michitaka; Takahashi, Mitsuhiro; Matsuura, Masana; Niibe, Hideo (Gunma Univ., Maebashi (Japan). School of Medicine)

    1984-10-01

    During the period from 1970 to 1980, 129 patients with laryngeal cancer were treated with radiation therapy alone in the Department of Radiology, Gunma University Hospital. The number of cases with glottic, supraglottic and subglottic cancer were 80 (62%), 38 (29%) and 11 (9%) respectively. The cumulative 5-year survival rate of cases with glottic cancer was 80% (stage I), 70% (stage II), 43% (stage III) and 0% (stage IV). The relative 5-year survival rate was 104%, 87%, 67% and 0%. Twenty-nine patients (36%) were older than 70 years. Of 54 cases with early (T1, T2) glottic cancer, 11 patients developed local relapses. They consist of seven T1a, one T1b and three T2 cases. The lymph nodal relapse was seen in a T1 case. The local relapses were ascribed to the lower tumor dose produced by the technical failures (4 cases) and to the histological factors (4 cases with papilloma like carcinoma). All of the T1 patients with relapses were salvaged with surgery. The larynges of 4 patients salvaged were still in fair preservation. Only one of 3 relapsed T2 cases was salvaged. These treatment results suggest that a regular check-up of general condition of the patients is very important for raising the survival rate, and that the radiation therapy should be first selected for preservation of the larynx in the early glottic cancer.

  9. Study on radiation therapy for prostatic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, T. (Yokohama City Univ. (Japan). Faculty of Medicine)

    1981-10-01

    In an attempt to clarify the effects of radiation therapy for prostatic cancer, the author studied 71 prostatic cancer patients with megavoltage radiation therapy at the Cancer Institute Hospital for the past 17 years between 1964 and 1980. Fifty nine out of 71 cases received combined treatment with hormone. Of 71, 28 patients were examined for remaining foci by transperineal needle biopsy at various times after irradiation. The 5-year actuarial survival rate was 100% for stage A, 92% for stage B, 60.2% for stage C and 25.2% for stage D, respectively. Local control rates by digital rectal examination were 92.3% for stage B and 65.5% for stage C, whereas local atrophy rates were 61.5% for stage B and 31% for stage C cases. The positive rate of biopsy was 75%, negative rate was 20.8% and false negative rate was 4.2% within 1 year. The positive rate decreased to 63.6%, while negative rate increased to 31.8% and false positive rate was 4.6% after 1 year. Some cases, in whom the size of the prostate had decreased, showed good prognosis despite the presence of viable cells in biopsy specimens, therefore the waiting policy seemed indicated by frequent local palpation in future follow up to examine any regrowth in size of the lesion.

  10. The role of medical physics in prostate cancer radiation therapy.

    Science.gov (United States)

    Fiorino, Claudio; Seuntjens, Jan

    2016-03-01

    Medical physics, both as a scientific discipline and clinical service, hugely contributed and still contributes to the advances in the radiotherapy of prostate cancer. The traditional translational role in developing and safely implementing new technology and methods for better optimizing, delivering and monitoring the treatment is rapidly expanding to include new fields such as quantitative morphological and functional imaging and the possibility of individually predicting outcome and toxicity. The pivotal position of medical physicists in treatment personalization probably represents the main challenge of current and next years and needs a gradual change of vision and training, without losing the traditional and fundamental role of physicists to guarantee a high quality of the treatment. The current focus issue is intended to cover traditional and new fields of investigation in prostate cancer radiation therapy with the aim to provide up-to-date reference material to medical physicists daily working to cure prostate cancer patients. The papers presented in this focus issue touch upon present and upcoming challenges that need to be met in order to further advance prostate cancer radiation therapy. We suggest that there is a smart future for medical physicists willing to perform research and innovate, while they continue to provide high-quality clinical service. However, physicists are increasingly expected to actively integrate their implicitly translational, flexible and high-level skills within multi-disciplinary teams including many clinical figures (first of all radiation oncologists) as well as scientists from other disciplines. Copyright © 2016. Published by Elsevier Ltd.

  11. Potential for heavy particle radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M.R.; Phillips, T.L.

    1977-03-01

    Radiation therapy remains one of the major forms of cancer treatment. When x rays are used in radiotherapy, there are large variations in radiation sensitivity among tumors because of the possible differences in the presence of hypoxic but viable tumor cells, differences in reoxygenation during treatment, differences in distribution of the tumor cells in their cell cycle, and differences in repair of sublethal damage. When high-LET particles are used, depending upon the LET distribution, these differences are reduced considerably. Because of these differences between x rays and high-LET particle effects, the high-LET particles may be more effective on tumor cells for a given effect on normal cells. Heavy particles have potential application in improving radiotherapy because of improved dose localization and possible advantages of high-LET particles due to their radiobiological characteristics. Protons, because of their defined range, Bragg peak, and small effects of scattering, have good dose localization characteristics. The use of protons in radiotherapy minimizes the morbidity of radiotherapy treatment and is very effective in treating deep tumors located near vital structures. Fast neutrons have no physical advantages over /sup 60/Co gamma rays but, because of their high-LET component, could be very effective in treating tumors that are resistant to conventional radiations. Negative pions and heavy ions combine some of the advantages of protons and fast neutrons.

  12. Better Efficacy of Synchrotron Spatially Microfractionated Radiation Therapy Than Uniform Radiation Therapy on Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Bouchet, Audrey, E-mail: audrey.m.bouchet@gmail.com [Université Grenoble Alpes, Grenoble Institut des Neurosciences, Grenoble (France); Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble (France); Bräuer-Krisch, Elke; Prezado, Yolanda [Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble (France); El Atifi, Michèle [Université Grenoble Alpes, Grenoble Institut des Neurosciences, Grenoble (France); Grenoble University Hospital, Grenoble (France); Rogalev, Léonid; Le Clec' h, Céline [Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble (France); Laissue, Jean Albert [University of Bern, Bern (Switzerland); Pelletier, Laurent, E-mail: laurent.pelletier@ujf-grenoble.fr [Université Grenoble Alpes, Grenoble Institut des Neurosciences, Grenoble (France); Grenoble University Hospital, Grenoble (France); Le Duc, Géraldine [Biomedical Beamline, European Synchrotron Radiation Facility, Grenoble (France)

    2016-08-01

    Purpose: Synchrotron microbeam radiation therapy (MRT) is based on the spatial fractionation of the incident, highly focused synchrotron beam into arrays of parallel microbeams, typically a few tens of microns wide and depositing several hundred grays. This irradiation modality was shown to have a high therapeutic impact on tumors, especially in intracranial locations. However, mechanisms responsible for such a property are not fully understood. Methods and Materials: Thanks to recent progress in dosimetry, we compared the effect of MRT and synchrotron broad beam (BB) radiation therapy delivered at comparable doses (equivalent to MRT valley dose) on tumor growth control and on classical radiobiological functions by histologic evaluation and/or transcriptomic analysis. Results: MRT significantly improved survival of rats bearing 9L intracranial glioma compared with BB radiation therapy delivered at a comparable dose (P<.001); the efficacy of MRT and BB radiation therapy was similar when the MRT dose was half that of BB. The greater efficacy of MRT was not correlated with a difference in cell proliferation (Mki67 and proliferating cell nuclear antigen) or in transcriptomic stimulation of angiogenesis (vascular endothelial growth factor A or tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 2) but was correlated with a higher cell death rate (factor for apoptosis signals) and higher recruitment of macrophages (tyrosine kinase with immunoglobulin-like and epidermal growth factor-like domains 1 and CD68 transcripts) a few days after MRT. Conclusions: These results show the superiority of MRT over BB radiation therapy when applied at comparable doses, suggesting that spatial fractionation is responsible for a specific and particularly efficient tissue response. The higher induction of cell death and immune cell activation in brain tumors treated by MRT may be involved in such responses.

  13. Intensity-Modulated Radiation Therapy Improves the Target Coverage Over 3-D Planning While Meeting Lung Tolerance Doses for All Patients With Malignant Pleural Mesothelioma.

    Science.gov (United States)

    Ulger, Sukran; Cetin, Eren; Catli, Serap; Sarac, Hilal; Kilic, Diclehan; Bora, Huseyin

    2017-06-01

    To investigate high conformality on target coverage and the ability on creating strict lung dose limitation of intensity-modulated radiation therapy in malignant pleural mesothelioma. Twenty-four radiation therapy plannings were evaluated and compared with dosimetric outcomes of conformal radiation therapy and intensity-modulated radiation therapy. Hemithoracal radiation therapy was performed on 12 patients with a fraction of 1.8 Gy to a total dose of 50.4 Gy. All organs at risk were contoured. Radiotherapy plannings were differed according to the technique; conformal radiation therapy was planned with conventionally combined photon-electron fields, and intensity-modulated radiation therapy was planned with 7 to 9 radiation beam angles optimized in inverse planning. Strict dose-volume constraints were applied. Intensity-modulated radiation therapy was statistically superior in target coverage and dose homogeneity (intensity-modulated radiation therapy-planning target volume 95 mean 100%; 3-dimensional conformal radiation therapy-planning target volume 95 mean 71.29%, P = .0001; intensity-modulated radiation therapy-planning target volume 105 mean 11.14%; 3-dimensional conformal radiation therapy-planning target volume 105 mean 35.69%, P = .001). The dosimetric results of the remaining lung was below the limitations on intensity-modulated radiation therapy planning data (intensity-modulated radiation therapy-lung mean dose mean 7.5 [range: 5.6%-8.5%]; intensity-modulated radiation therapy-lung V5 mean 55.55% [range: 47%-59.9%]; intensity-modulated radiation therapy-lung V20 mean 4.5% [range: 0.5%-9.5%]; intensity-modulated radiation therapy-lung V13 mean 13.43% [range: 4.2%-22.9%]). With a complex and large target volume of malignant pleural mesothelioma, intensity-modulated radiation therapy has the ability to deliver efficient tumoricidal radiation dose within the safe dose limits of the remaining lung tissue.

  14. Optimal primary therapy of ovarian cancer.

    Science.gov (United States)

    Bookman, M A

    2016-04-01

    Epithelial ovarian cancer continues to have the highest case-fatality ratio of all gynecologic cancers, in spite of ongoing advances in risk-assessment, genomics, tumor biology, cytoreductive surgery, chemotherapy, and molecular-targeted interventions. Primary treatment options for advanced-stage disease not only should reflect current best standards, but also need to be tailored for individual patients, with consideration of local resources. Formulation of recommendations for optimal primary therapy based on a selective review of data from completed randomized trials, analysis of ongoing trials, and integration with current tumor biology, within the context of individualized clinical care. Recommendations were presented for discussion during an international meeting of experts in ovarian cancer treatment. Key recommendations include full adjuvant therapy for early-stage high-grade serous cancer; tailored utilization of neoadjuvant chemotherapy based on patient comorbidities, extent of disease, and likelihood of achieving optimal surgical cytoreduction; preferred utilization of carboplatin with weekly paclitaxel as primary therapy; consideration of intraperitoneal cisplatin-based therapy in appropriate patients; avoidance of maintenance chemotherapy; lack of necessity for bevacizumab during primary chemotherapy and primary maintenance; acknowledgement of research opportunities and priorities. Integrated multidisciplinary care, including cytoreductive surgery and platinum-based chemotherapy, remain central to the optimal management of women with advanced-stage ovarian cancer. However, even with recent technical advances, the impact on disease-related mortality is limited, and more attention will be focused on the early integration of research, particularly with neoadjuvant chemotherapy and interval cytoreductive surgery. © The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For

  15. Prone Breast Intensity Modulated Radiation Therapy: 5-Year Results

    Energy Technology Data Exchange (ETDEWEB)

    Osa, Etin-Osa O.; DeWyngaert, Keith [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States); Roses, Daniel [Department of Surgery, New York University School of Medicine, New York, New York (United States); Speyer, James [Department of Medical Oncology, New York University School of Medicine, New York, New York (United States); Guth, Amber; Axelrod, Deborah [Department of Surgery, New York University School of Medicine, New York, New York (United States); Fenton Kerimian, Maria [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States); Goldberg, Judith D. [Department of Population Health, New York University School of Medicine, New York, New York (United States); Formenti, Silvia C., E-mail: Silvia.formenti@nyumc.org [Department of Radiation Oncology, New York University School of Medicine, New York, New York (United States)

    2014-07-15

    Purpose: To report the 5-year results of a technique of prone breast radiation therapy delivered by a regimen of accelerated intensity modulated radiation therapy with a concurrent boost to the tumor bed. Methods and Materials: Between 2003 and 2006, 404 patients with stage I-II breast cancer were prospectively enrolled into 2 consecutive protocols, institutional trials 03-30 and 05-181, that used the same regimen of 40.5 Gy/15 fractions delivered to the index breast over 3 weeks, with a concomitant daily boost to the tumor bed of 0.5 Gy (total dose 48 Gy). All patients were treated after segmental mastectomy and had negative margins and nodal assessment. Patients were set up prone: only if lung or heart volumes were in the field was a supine setup attempted and chosen if found to better spare these organs. Results: Ninety-two percent of patients were treated prone, 8% supine. Seventy-two percent had stage I, 28% stage II invasive breast cancer. In-field lung volume ranged from 0 to 228.27 cm{sup 3}, mean 19.65 cm{sup 3}. In-field heart volume for left breast cancer patients ranged from 0 to 21.24 cm{sup 3}, mean 1.59 cm{sup 3}. There was no heart in the field for right breast cancer patients. At a median follow-up of 5 years, the 5-year cumulative incidence of isolated ipsilateral breast tumor recurrence was 0.82% (95% confidence interval [CI] 0.65%-1.04%). The 5-year cumulative incidence of regional recurrence was 0.53% (95% CI 0.41%-0.69%), and the 5-year overall cumulative death rate was 1.28% (95% CI 0.48%-3.38%). Eighty-two percent (95% CI 77%-85%) of patients judged their final cosmetic result as excellent/good. Conclusions: Prone accelerated intensity modulated radiation therapy with a concomitant boost results in excellent local control and optimal sparing of heart and lung, with good cosmesis. Radiation Therapy Oncology Group protocol 1005, a phase 3, multi-institutional, randomized trial is ongoing and is evaluating the equivalence of a similar dose and

  16. In-Space Radiator Shape Optimization using Genetic Algorithms

    Science.gov (United States)

    Hull, Patrick V.; Kittredge, Ken; Tinker, Michael; SanSoucie, Michael

    2006-01-01

    Future space exploration missions will require the development of more advanced in-space radiators. These radiators should be highly efficient and lightweight, deployable heat rejection systems. Typical radiators for in-space heat mitigation commonly comprise a substantial portion of the total vehicle mass. A small mass savings of even 5-10% can greatly improve vehicle performance. The objective of this paper is to present the development of detailed tools for the analysis and design of in-space radiators using evolutionary computation techniques. The optimality criterion is defined as a two-dimensional radiator with a shape demonstrating the smallest mass for the greatest overall heat transfer, thus the end result is a set of highly functional radiator designs. This cross-disciplinary work combines topology optimization and thermal analysis design by means of a genetic algorithm The proposed design tool consists of the following steps; design parameterization based on the exterior boundary of the radiator, objective function definition (mass minimization and heat loss maximization), objective function evaluation via finite element analysis (thermal radiation analysis) and optimization based on evolutionary algorithms. The radiator design problem is defined as follows: the input force is a driving temperature and the output reaction is heat loss. Appropriate modeling of the space environment is added to capture its effect on the radiator. The design parameters chosen for this radiator shape optimization problem fall into two classes, variable height along the width of the radiator and a spline curve defining the -material boundary of the radiator. The implementation of multiple design parameter schemes allows the user to have more confidence in the radiator optimization tool upon demonstration of convergence between the two design parameter schemes. This tool easily allows the user to manipulate the driving temperature regions thus permitting detailed design of in

  17. Stereotactic Body Radiation Therapy for Oligometastatic Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Muldermans, Jonathan L. [F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland (United States); Romak, Lindsay B. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Kwon, Eugene D. [Department of Urology, Mayo Clinic, Rochester, Minnesota (United States); Department of Immunology, Mayo Clinic, Rochester, Minnesota (United States); Park, Sean S. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Olivier, Kenneth R., E-mail: olivier.kenneth@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States)

    2016-06-01

    Purpose: To review outcomes of patients with oligometastatic prostate cancer (PCa) treated with stereotactic body radiation therapy (SBRT) and to identify variables associated with local failure. Methods and Materials: We retrospectively reviewed records of patients treated with SBRT for oligometastatic PCa. Metastasis control (ie, control of the treated lesion, MC), biochemical progression-free survival, distant progression-free survival, and overall survival were estimated with the Kaplan-Meier method. Results: Sixty-six men with 81 metastatic PCa lesions, 50 of which were castrate-resistant, were included in the analysis. Lesions were in bone (n=74), lymph nodes (n=6), or liver (n=1). Stereotactic body radiation therapy was delivered in 1 fraction to 71 lesions (88%), at a median dose of 16 Gy (range, 16-24 Gy). The remaining lesions received 30 Gy in 3 fractions (n=6) or 50 Gy in 5 fractions (n=4). Median follow-up was 16 months (range, 3-49 months). Estimated MC at 2 years was 82%. Biochemical progression-free survival, distant progression-free survival, and overall survival were 54%, 45%, and 83%, respectively. On multivariate analysis, only the dose of SBRT was significantly associated with MC; lesions treated with 16 Gy had 58% MC, and those treated with ≥18 Gy had 95% MC at 2 years (P≤.001). At 2 years, MC for lesions treated with 18 Gy (n=21) was 88%. No patient treated with ≥18 Gy in a single fraction or with any multifraction regimen had local failure. Six patients (9%) had grade 1 pain flare, and 2 (3%) had grade 2 pain flare. No grade 2 or greater late toxicities were reported. Conclusions: Stereotactic body radiation therapy for patients with oligometastatic prostate cancer provided optimal metastasis control and acceptable toxicity with doses ≥18 Gy. Biochemical progression-free survival was 54% at 16 months with the inclusion of SBRT in the treatment regimen. Stereotactic body radiation therapy should be considered in

  18. Are Patients Traveling for Intraoperative Radiation Therapy?

    Directory of Open Access Journals (Sweden)

    Kelsey E. Larson

    2017-01-01

    Full Text Available Purpose. One benefit of intraoperative radiation therapy (IORT is that it usually requires a single treatment, thus potentially eliminating distance as a barrier to receipt of whole breast irradiation. The aim of this study was to evaluate the distance traveled by IORT patients at our institution. Methods. Our institutional prospective registry was used to identify IORT patients from 10/2011 to 2/2017. Patient’s home zip code was compared to institution zip code to determine travel distance. Characteristics of local (100 miles patients were compared. Results. 150 were patients included with a median travel distance of 27 miles and mean travel distance of 121 miles. Most were local (68.7%, with the second largest group living faraway (20.0%. Subset analysis of local patients demonstrated 20.4% traveled 1000 miles. The local, regional, and faraway patients did not differ with respect to age, race, tumor characteristics, or whole breast irradiation. Conclusions. Breast cancer patients are traveling for IORT, with 63% traveling >20 miles for care. IORT is an excellent strategy to promote breast conservation in selected patients, particularly those who live remote from a radiation facility.

  19. Ultraviolet radiation therapy and UVR dose models.

    Science.gov (United States)

    Grimes, David Robert

    2015-01-01

    Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed.

  20. [New strategies to interfere with radiation response: "biomodulation" of radiation therapy].

    Science.gov (United States)

    Deutsch, E; Kaliski, A; Maggiorella, L; Bourhis, J

    2005-03-01

    The development of several new anti cancer agents has been made possible because of recent significant achievements in our global understanding of cancer biology. These new "targeted" agents selectively inhibit targets necessary for tumor cell growth and viability with little toxicity to normal cells compared to conventional cytotoxic agents. So far, the efficacy of many of these new promising agents when used alone treatment remains limited, it is likely that the optimal use of these agents could be obtained in combination with conventional agents such as radiation therapy. The potential benefit of these targeted therapies combined with irradiation seems important. They might offer the advantage of increasing the tumor response to radiation with no or little increase in normal tissue damage. Therefore, these new types of chemo-radiation approaches might respect the normal tissue versus tumor cell "therapeutic ratio". These approaches can be sub divided in three sub groups: 1) Therapeutics targeting selectively one tumor related biochemical activity such as EGFR inhibitors. These approaches are efficient but one mutation of the target might render them inefficient. 2) Therapeutics directed against a widely expressed target. This is the case for anti Insulin Growth Factor-1 (IGF1R) interventions: IGF1R inhibition seems to specifically alter tumor cell viability with a minimal effect on normal cells viability. 3) Strategies which are not targeted against the tumor but the microenvironment, especially angiogenesis. This type of approaches seems to be applicable independently of tumor intrinsic biologic related factors.

  1. Efficacy of Six Weeks Infrared Radiation Therapy on Chronic Low ...

    African Journals Online (AJOL)

    TNHJOURNALPH

    The beneficial effect of infrared radiation therapy on chronic low back pain and functional disability as seen in this present study may be related to the hypothesized theory that infrared radiation therapy reduces pain intensity by, vascular changes in blood flow, reflex activity, possibly through the activation of pain gate theory ...

  2. Occurrence of BOOP outside radiation field after radiation therapy for small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hamanishi, Tohru; Oida, Kazukiyo [Tenri Hospital, Nara (Japan); Morimatu, Takafumi (and others)

    2001-09-01

    We report a case of bronchiolitis obliterans organizing pneumonia (BOOP) that occurred outside the radiation field after radiation therapy for small cell lung cancer. A 74-year-old woman received chemotherapy and a total of 60 Gy of radiation therapy to the right hilum and mediastinum for small cell carcinoma of the suprahilar area of the right lung. Radiation pneumonitis developed within the radiation port 3 months after the completion of radiation therapy. She complained of cough and was admitted 7 months after completion of the radiation therapy. Chest radiography and computed tomography demonstrated peripheral alveolar opacities outside the radiation field on the side contralateral to that receiving the radiation therapy. Bronchoalveolar lavage showed that the total cell count was increased, with a markedly increased percentage of lymphocytes. Transbronchial lung biopsy revealed a histologic pattern consistent with BOOP. Treatment with corticosteroids resulted in rapid improvement of the symptoms and complete resolution of the radiographic abnormalities of the left lung. Although some cases of BOOP following radiation therapy for breast cancer have been reported, none of BOOP after radiation therapy for lung cancer have appeared in the literature. (author)

  3. Scalp Dose Evaluation According Radiation Therapy Technique of Whole Brain Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2011-09-15

    Opposing portal irradiation with helmet field shape that has been given to a patient with brain metastasis can cause excess dose in patient's scalp, resulting in hair loss. For this reason, this study is to quantitatively analyze scalp dose for effective prevention of hair loss by comparing opposing portal irradiation with scalp-shielding shape and tomotherapy designed to protect patient's scalp with conventional radiation therapy. Scalp dose was measured by using three therapies (HELMET, MLC, TOMO) after five thermo-luminescence dosimeters were positioned along center line of frontal lobe by using RANDO Phantom. Scalp dose and change in dose distribution were compared and analyzed with DVH after radiation therapy plan was made by using Radiation Treatment Planning System (Pinnacle3, Philips Medical System, USA) and 6 MV X-ray (Clinac 6EX, VARIAN, USA). When surface dose of scalp by using thermo-luminescence dosimeters was measured, it was revealed that scalp dose decreased by average 87.44% at each point in MLC technique and that scalp dose decreased by average 88.03% at each point in TOMO compared with HELMET field therapy. In addition, when percentage of volume (V95%, V100%, V105% of prescribed dose) was calculated by using Dose Volume Histogram (DVH) in order to evaluate the existence or nonexistence of hotspot in scalp as to three therapies (HELMET, MLC, TOMO), it was revealed that MLC technique and TOMO plan had good dose coverage and did not have hot spot. Reducing hair loss of a patient who receives whole brain radiotherapy treatment can make a contribution to improve life quality of the patient. It is expected that making good use of opposing portal irradiation with scalp-shielding shape and tomotherapy to protect scalp of a patient based on this study will reduce hair loss of a patient.

  4. Modern Radiation Therapy for Hodgkin Lymphoma: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group (ILROG)

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Lena, E-mail: lena.specht@regionh.dk [Department of Oncology and Hematology, Rigshospitalet, University of Copenhagen (Denmark); Yahalom, Joachim [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Illidge, Tim [Institute of Cancer Sciences, University of Manchester, Manchester Academic Health Sciences Centre, Christie Hospital NHS Trust, Manchester (United Kingdom); Berthelsen, Anne Kiil [Department of Radiation Oncology and PET Centre, Rigshospitalet, University of Copenhagen (Denmark); Constine, Louis S. [Department of Radiation Oncology and Pediatrics, James P. Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York (United States); Eich, Hans Theodor [Department of Radiation Oncology, University of Münster (Germany); Girinsky, Theodore [Department of Radiation Oncology, Institut Gustave-Roussy, Villejuif (France); Hoppe, Richard T. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Mauch, Peter [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard University, Boston, Massachusetts (United States); Mikhaeel, N. George [Department of Clinical Oncology and Radiotherapy, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Ng, Andrea [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard University, Boston, Massachusetts (United States)

    2014-07-15

    Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solely on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the

  5. Bioluminescence Tomography–Guided Radiation Therapy for Preclinical Research

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bin [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland (United States); Wang, Ken Kang-Hsin, E-mail: kwang27@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland (United States); Yu, Jingjing [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland (United States); School of Physics and Information Technology, Shaanxi Normal University, Shaanxi (China); Eslami, Sohrab; Iordachita, Iulian [Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, Maryland (United States); Reyes, Juvenal; Malek, Reem [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland (United States); Tran, Phuoc T. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland (United States); Department of Oncology and Urology, Brady Urological Institute, Johns Hopkins University, Baltimore, Maryland (United States); Patterson, Michael S. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario (Canada); Wong, John W. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland (United States)

    2016-04-01

    Purpose: In preclinical radiation research, it is challenging to localize soft tissue targets based on cone beam computed tomography (CBCT) guidance. As a more effective method to localize soft tissue targets, we developed an online bioluminescence tomography (BLT) system for small-animal radiation research platform (SARRP). We demonstrated BLT-guided radiation therapy and validated targeting accuracy based on a newly developed reconstruction algorithm. Methods and Materials: The BLT system was designed to dock with the SARRP for image acquisition and to be detached before radiation delivery. A 3-mirror system was devised to reflect the bioluminescence emitted from the subject to a stationary charge-coupled device (CCD) camera. Multispectral BLT and the incomplete variables truncated conjugate gradient method with a permissible region shrinking strategy were used as the optimization scheme to reconstruct bioluminescent source distributions. To validate BLT targeting accuracy, a small cylindrical light source with high CBCT contrast was placed in a phantom and also in the abdomen of a mouse carcass. The center of mass (CoM) of the source was recovered from BLT and used to guide radiation delivery. The accuracy of the BLT-guided targeting was validated with films and compared with the CBCT-guided delivery. In vivo experiments were conducted to demonstrate BLT localization capability for various source geometries. Results: Online BLT was able to recover the CoM of the embedded light source with an average accuracy of 1 mm compared to that with CBCT localization. Differences between BLT- and CBCT-guided irradiation shown on the films were consistent with the source localization revealed in the BLT and CBCT images. In vivo results demonstrated that our BLT system could potentially be applied for multiple targets and tumors. Conclusions: The online BLT/CBCT/SARRP system provides an effective solution for soft tissue targeting, particularly for small, nonpalpable, or

  6. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a (60)Co Magnetic Resonance Image Guidance Radiation Therapy System

    DEFF Research Database (Denmark)

    Wooten, H Omar; Green, Olga; Yang, Min

    2015-01-01

    PURPOSE: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating (60)Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. METHODS AND MATERIALS...

  7. Cancer and Radiation Therapy: Current Advances and Future Directions

    Science.gov (United States)

    Baskar, Rajamanickam; Lee, Kuo Ann; Yeo, Richard; Yeoh, Kheng-Wei

    2012-01-01

    In recent years remarkable progress has been made towards the understanding of proposed hallmarks of cancer development and treatment. However with its increasing incidence, the clinical management of cancer continues to be a challenge for the 21st century. Treatment modalities comprise of radiation therapy, surgery, chemotherapy, immunotherapy and hormonal therapy. Radiation therapy remains an important component of cancer treatment with approximately 50% of all cancer patients receiving radiation therapy during their course of illness; it contributes towards 40% of curative treatment for cancer. The main goal of radiation therapy is to deprive cancer cells of their multiplication (cell division) potential. Celebrating a century of advances since Marie Curie won her second Nobel Prize for her research into radium, 2011 has been designated the Year of Radiation therapy in the UK. Over the last 100 years, ongoing advances in the techniques of radiation treatment and progress made in understanding the biology of cancer cell responses to radiation will endeavor to increase the survival and reduce treatment side effects for cancer patients. In this review, principles, application and advances in radiation therapy with their biological end points are discussed. PMID:22408567

  8. Use of proximal operator graph solver for radiation therapy inverse treatment planning.

    Science.gov (United States)

    Liu, Xinmin; Pelizzari, Charles; Belcher, Andrew H; Grelewicz, Zachary; Wiersma, Rodney D

    2017-04-01

    Most radiation therapy optimization problems can be formulated as an unconstrained problem and solved efficiently by quasi-Newton methods such as the Limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm. However, several next generation planning techniques such as total variation regularization- based optimization and MV+kV optimization, involve constrained or mixed-norm optimization, and cannot be solved by quasi-Newton methods. Using standard optimization algorithms on such problems often leads to prohibitively long optimization times and large memory requirements. This work investigates the use of a recently developed proximal operator graph solver (POGS) in solving such radiation therapy optimization problems. Radiation therapy inverse treatment planning was formulated as a graph form problem, and the proximal operators of POGS for quadratic optimization were derived. POGS was exploited for the first time to impose hard dose constraints along with soft constraints in the objective function. The solver was applied to several clinical treatment sites (TG119, liver, prostate, and head&neck), and the results were compared to the solutions obtained by other commercial and non-commercial optimizers. For inverse planning optimization with nonnegativity box constraints on beamlet intensity, the speed of POGS can compete with that of LBFGSB in some situations. For constrained and mixed-norm optimization, POGS is about one or two orders of magnitude faster than the other solvers while requiring less computer memory. POGS was used for solving inverse treatment planning problems involving constrained or mixed-norm formulation on several example sites. This approach was found to improve upon standard solvers in terms of computation speed and memory usage, and is capable of solving traditionally difficult problems, such as total variation regularization-based optimization and combined MV+kV optimization. © 2017 American Association of Physicists in Medicine.

  9. On probabilistically defined margins in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Papiez, Lech; Langer, Mark [Department of Radiation Oncology, Indiana University, Indianapolis, IN (United States)

    2006-08-21

    Margins about a target volume subject to external beam radiation therapy are designed to assure that the target volume of tissue to be sterilized by treatment is adequately covered by a lethal dose. Thus, margins are meant to guarantee that all potential variation in tumour position relative to beams allows the tumour to stay within the margin. Variation in tumour position can be broken into two types of dislocations, reducible and irreducible. Reducible variations in tumour position are those that can be accommodated with the use of modern image-guided techniques that derive parameters for compensating motions of patient bodies and/or motions of beams relative to patient bodies. Irreducible variations in tumour position are those random dislocations of a target that are related to errors intrinsic in the design and performance limitations of the software and hardware, as well as limitations of human perception and decision making. Thus, margins in the era of image-guided treatments will need to accommodate only random errors residual in patient setup accuracy (after image-guided setup corrections) and in the accuracy of systems designed to track moving and deforming tissues of the targeted regions of the patient's body. Therefore, construction of these margins will have to be based on purely statistical data. The characteristics of these data have to be determined through the central limit theorem and Gaussian properties of limiting error distributions. In this paper, we show how statistically determined margins are to be designed in the general case of correlated distributions of position errors in three-dimensional space. In particular, we show how the minimal margins for a given level of statistical confidence are found. Then, how they are to be used to determine geometrically minimal PTV that provides coverage of GTV at the assumed level of statistical confidence. Our results generalize earlier recommendations for statistical, central limit theorem

  10. On probabilistically defined margins in radiation therapy

    Science.gov (United States)

    Papiez, Lech; Langer, Mark

    2006-08-01

    Margins about a target volume subject to external beam radiation therapy are designed to assure that the target volume of tissue to be sterilized by treatment is adequately covered by a lethal dose. Thus, margins are meant to guarantee that all potential variation in tumour position relative to beams allows the tumour to stay within the margin. Variation in tumour position can be broken into two types of dislocations, reducible and irreducible. Reducible variations in tumour position are those that can be accommodated with the use of modern image-guided techniques that derive parameters for compensating motions of patient bodies and/or motions of beams relative to patient bodies. Irreducible variations in tumour position are those random dislocations of a target that are related to errors intrinsic in the design and performance limitations of the software and hardware, as well as limitations of human perception and decision making. Thus, margins in the era of image-guided treatments will need to accommodate only random errors residual in patient setup accuracy (after image-guided setup corrections) and in the accuracy of systems designed to track moving and deforming tissues of the targeted regions of the patient's body. Therefore, construction of these margins will have to be based on purely statistical data. The characteristics of these data have to be determined through the central limit theorem and Gaussian properties of limiting error distributions. In this paper, we show how statistically determined margins are to be designed in the general case of correlated distributions of position errors in three-dimensional space. In particular, we show how the minimal margins for a given level of statistical confidence are found. Then, how they are to be used to determine geometrically minimal PTV that provides coverage of GTV at the assumed level of statistical confidence. Our results generalize earlier recommendations for statistical, central limit theorem

  11. Results of PWO Radiation Hardness Optimization.

    CERN Document Server

    Drobychev, Gleb; Auffray, Etiennette; Borisevich, A E; Korzhik, Mikhail; Kostylev, V; Lecoq, Paul; Ligoun, V D; Peigneux, Jean-Pierre

    1999-01-01

    The results of analysis of the PWO radiation hardness depending of crystal growth technology are presented. The PWO crystals of different crystallization numbers with one kind of doping and double doped as well as crystals grown from recycled raw materials were analyzed. The presented results show high level of crystal technology reproducibility. More than 95% of double doped crystals satisfy to the CMS ECAL specification requirements.

  12. Cardiac resynchronization therapy optimization by finger plethysmography.

    Science.gov (United States)

    Butter, Christian; Stellbrink, Christoph; Belalcazar, Andres; Villalta, Don; Schlegl, Michael; Sinha, Anil; Cuesta, Francisca; Reister, Craig

    2004-11-01

    We tested a simple noninvasive method for cardiac resynchronization therapy (CRT) optimization using standard finger photoplethysmography (FPPG). CRT can increase left ventricular cardiac output in patients with heart failure and ventricular conduction delay. Optimal therapy delivery depends on an appropriate AV delay. Multiple invasive and noninvasive methods have been attempted to identify patients and the best AV delay for CRT, but all suffer from a combination of high patient risk, cost, complexity, and low reproducibility. FPPG and invasive aortic pressure data were simultaneously collected from 57 heart failure patients during intrinsic rhythm alternating with very brief periods of pacing at 4 to 5 AV delays. After correcting data for artifacts, the median percentage responses for each AV delay were classified as positive, negative, or neutral compared to baseline (Wilcoxon rank test). FPPG correctly identified positive aortic pulse pressure responses with 71% sensitivity (95% CI: 60-80%) and 90% specificity (95% CI: 84-94%) and negative aortic pulse pressure responses with 57% sensitivity (95% CI: 44-69%) and 96% specificity (95% CI: 91-98%). The magnitude of FPPG changes were strongly correlated with positive aortic pulse pressure changes (R(2) = 0.73, P < .0001) but less well correlated with negative aortic pulse pressure changes (R(2) = 0.43, P < .0001). FPPG selected 78% of the patients having positive aortic pulse pressure changes to CRT and identified the AV delay giving maximum aortic pulse pressure change in all selected patients. FPPG can provide a simple noninvasive method for identifying significant changes in aortic pulse pressure with high specificity, including identifying patients in whom aortic pulse pressure increases with CRT and the AV delay giving the maximum aortic pulse pressure.

  13. State population as a predictor of radiation therapy staffing levels.

    Science.gov (United States)

    Culbertson, John; Carbonneau, Kira; Kudlas, Myke

    2012-05-01

    Considering the cyclical nature of shortages and oversupplies of staffing levels in the labor force, an accurate prediction of future demand for personnel is of great importance. Historically, the profession of radiation therapy has been plagued with these cycles. This study establishes state population as a strong predictor of radiation therapy staffing levels. A linear regression analysis was performed to determine the association between state population and radiation therapy staffing levels from 2002 to 2010. State population is a significant and substantial predictor variable for the number of actively employed and registered radiation therapists, with 89.5% to 91.4% of the variance accounted for from 2002 to 2010. Additional research in estimating future demand in radiation therapy is possible. By monitoring change in state population, health care professionals can proactively address cycles of shortages and oversupplies in staffing levels. Copyright © 2012 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  14. New technologies in radiation therapy: ensuring patient safety, radiation safety and regulatory issues in radiation oncology.

    Science.gov (United States)

    Amols, Howard I

    2008-11-01

    New technologies such as intensity modulated and image guided radiation therapy, computer controlled linear accelerators, record and verify systems, electronic charts, and digital imaging have revolutionized radiation therapy over the past 10-15 y. Quality assurance (QA) as historically practiced and as recommended in reports such as American Association of Physicists in Medicine Task Groups 40 and 53 needs to be updated to address the increasing complexity and computerization of radiotherapy equipment, and the increased quantity of data defining a treatment plan and treatment delivery. While new technology has reduced the probability of many types of medical events, seeing new types of errors caused by improper use of new technology, communication failures between computers, corrupted or erroneous computer data files, and "software bugs" are now being seen. The increased use of computed tomography, magnetic resonance, and positron emission tomography imaging has become routine for many types of radiotherapy treatment planning, and QA for imaging modalities is beyond the expertise of most radiotherapy physicists. Errors in radiotherapy rarely result solely from hardware failures. More commonly they are a combination of computer and human errors. The increased use of radiosurgery, hypofractionation, more complex intensity modulated treatment plans, image guided radiation therapy, and increasing financial pressures to treat more patients in less time will continue to fuel this reliance on high technology and complex computer software. Clinical practitioners and regulatory agencies are beginning to realize that QA for new technologies is a major challenge and poses dangers different in nature than what are historically familiar.

  15. Geometric accuracy in radiation therapy: Dosimetric, imaging and economic considerations

    Science.gov (United States)

    Ploquin, Nicolas P.

    In 2007 in Canada, 159,900 men and women will be diagnosed with cancer. Radiation Therapy (RT) is the treatment of cancer by irradiating malignant tissue with ionizing radiation and it is used on up to 50% of all cancers. The objective of radiation therapy is to deliver a lethal dose of radiation to the tumour while sparing the surrounding healthy tissues and organs at risks (OARs). Thus, the accuracy with which the radiation therapy process must be carried out is critical. The presence of setup errors and uncertainties throughout the RT process impacts the dose received by the tumour and OARs and can compromise the outcome for the patient. This thesis focuses on the study of the limiting geometrical accuracy imposed by factors present in radiation therapy process (such as setup errors and uncertainties or the spatial resolution of the imaging systems that we use) and its consequences for the patient. The consequences are quantified through the use of a physical outcome surrogate, the Equivalent Uniform Dose (EUD), which numerically describes the dose distribution received by the target and normal structures surrounding it. A cost-outcome analysis is presented in which the incremental cost of radiation therapy is directly related to the patients outcome (using the EUD) for using various imaging modalities and correction protocols in Image Guided Adaptive Radiation Therapy (IGART).

  16. Postoperative radiation therapy for esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Yasumasa; Ono, Koji; Imamura, Masayuki; Hiraoka, Masahiro; Takahashi, Masaji; Abe, Mitsuyuki; Ohishi, Ken; Yanagibashi, Ken; Tobe, Takayoshi (Kyoto Univ. (Japan). Faculty of Medicine)

    1989-04-01

    The value of postoperative radiation therapy (RT) was investigated in 77 patients with esophageal cancer resected between 1977 and 1986. Surgical resection was palliative in 13 of these patients. Although seven of them underwent postoperative irradiation to the residual tumor, all of the patients died within one year. Following potentially curative resection performed in 64 patients, 31 patients received 50 Gy of postoperative RT to the lower neck and the mediastinum (group Ia), seven were unable to receive full-dose postoperative RT (group Ib), and 26 were not treated with postoperative RT (group II). The 5-year survival rate estimated by the Kaplan-Meier method was 54% for group Ia, 29% for group Ib, and 33% for group II, with the difference between groups Ia and II being significant (p<0.025). The local recurrence rate in the mediastinum was lower in group Ia than in group II. Prophylactic postoperative RT for esophageal cancer is a safe and effective regimen for patients with resected disease. (author).

  17. Optimal control of radiator systems; Optimal reglering av radiatorsystem

    Energy Technology Data Exchange (ETDEWEB)

    Wollerstrand, J.; Ljunggren, P.; Johansson, P.O.

    2007-07-01

    This report presents results from a study aiming to considerably improve the development towards minimizing the primary return temperature from a district heating (DH) substation by optimizing the control algorithm for the space heating system. The investigation of this research field started about 20 years ago in Sweden when low flow operation of space heating systems was introduced. Following a couple of years of partly confused discussions, the method was accepted by many, but was rejected by others. Our thesis is that further improvement of cooling of DH water is possible when advanced, but robust, control algorithms are used for the space heating system. A space heating system is traditionally designed for a specific constant circulation flow combined with a suitable control curve for the space heating supply temperature as a function of the outdoor temperature. Optimal choice of the control curve varies from case to case and is an issue both we and others have dealt with in previous work. A large step was to derive theoretical control curves for optimal control of the space heating system, with an analysis of how temperature and circulation flow varies with heat load. The estimated gain varies strongly depending on the conditions, however, with realistic conditions it can be as much as 5 deg C decreased DH return temperature on yearly average. To be able to work properly under varying physical circumstances, a control algorithm must be able to combine variation of space heating supply temperature and circulation flow as a function of the heat load. By regulating the rotation speed of the circulation pump this can be achieved. Such regulation can be adjusted for each and every building by regulating a few parameters in a regulator. The results from this work are, that important theoretical knowledge has been completed, to show results systematically and to find support from practical experiments. A hands-on description of the method for optimizing DH water

  18. Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Katrina, E-mail: Trinabena23@gmail.com; Lenards, Nishele; Holson, Janice

    2016-04-01

    The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient's neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient's data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain.

  19. COMPARISON OF HYPOFRACTIONATED RADIATION THERAPY VERSUS CONVENTIONAL RADIATION THERAPY IN POST MASTECTOMY BREAST CANCER

    Directory of Open Access Journals (Sweden)

    Abhilash

    2016-03-01

    Full Text Available INTRODUCTION Breast cancer is the most common cancer in women worldwide and a leading cause of cancer death in females and accounts for 1.8 million new cases and approximately 0.5 million deaths annually. Patients who present with locally advanced breast cancer (LABC require multidisciplinary team approach that incorporates diagnostic imaging, surgery, chemotherapy and histopathological assessment, including molecular-based studies, radiation, and, if indicated, biologic and hormonal therapies. Hypofractionated radiation therapy following mastectomy has been used in many institutions for several decades and have demonstrated equivalent local control, cosmetic and normal tissues between 50 Gy in 25 fractions and various hypofractionated radiotherapy prescriptions employing 13-16 fractions. Evidence suggests that hypofractionated radiotherapy may also be safe and effective for regional nodal disease. AIMS AND OBJECTIVES To compare the local control and side effects of hypofractionated radiation therapy with conventional radiation therapy in post mastectomy carcinoma breast with stage II and III and to compare the tolerability and compliance of both schedules. MATERIALS AND METHODS The study was conducted on 60 histopathologically proven patients of carcinoma of breast, treated surgically with modified radical mastectomy. Group I patients were given external radiation to chest flap and drainage areas, a dose of 39 Gy/13 fractions/3.1 weeks, a daily dose 3 Gy for 13 fractions in 4 days a week schedule and Group II patients were given external radiation to chest flap and drainage areas, a dose of 50 Gy/25 fractions/5 weeks, to receive a daily dose 2 Gy for 25 fractions in a 5 days a week schedule. RESULTS The median age at presentation in Group I and II was 48 and 50 years respectively. Locoregional control after completion of radiotherapy in Group I vs. Group II was 26/30 (86.7% vs. 27/30 (90% respectively. Acute reactions and their grades in Group

  20. Intravesical ozone therapy for progressive radiation-induced hematuria.

    Science.gov (United States)

    Clavo, Bernardino; Gutiérrez, Dominga; Martín, Dionisio; Suárez, Gerardo; Hernández, María A; Robaina, Francisco

    2005-06-01

    Progressive radiation-induced cystitis can become a serious clinical problem the therapeutic solution of which is limited and almost invariably aggressive. Ozone therapy is a nonconventional therapy that has been reported to offer benefits in late-onset wound healing and ischemic disorders. This report describes a patient with progressive radiation-induced hematuria from standard conservative treatment that was further treated with ozone therapy. Ozone therapy was achieved by intravesical instillation of ozonized bi-distilled water over a period of 30 minutes, three sessions per week during the first weeks. Later, ozone therapy sessions were decreased and involved ozonized water or direct intravesicular instillation of ozone at 20-25 microg/mL. Hematuria was successfully controlled by intravesical application of ozone therapy. The successes achieved with this technique suggest that intravesicular instillation of ozonized bi-distilled water or ozone merits further investigation with a view to its application to counter this radiation-induced side-effect.

  1. Waiting times for radiation therapy in Ontario.

    Science.gov (United States)

    Benk, Veronique; Przybysz, Raymond; McGowan, Tom; Paszat, Lawrence

    2006-02-01

    The mass media and clinical journals have reported lengthy waiting times after surgery before initiation of radiation therapy (RT) for cancer across Canada. We aimed to describe the length of time between the last date of surgery or biopsy or chemotherapy and first date of RT. This is a population-based study measuring waiting times for RT in Ontario among all patients with potentially curable cancer of the cervix, tonsil and larynx and a random sample of women who had had breast cancer resection, whose first date of RT fell between Sept. 1, 2001, and Aug. 31, 2002. Abstraction of original health care records provided each patient's demographics, cancer stage and cancer treatment (last surgery, consultation, simulation, first RT). Last dates of chemotherapy before RT were obtained from abstraction or from Ontario Health Insurance Plan (OHIP) files, and last dates of surgery before RT were compared with dates in the Canadian Institute for Health Information (CIHI) Discharge Abstract Database. Waiting times between the last date of surgery or chemotherapy and the first date of RT varied significantly among the health regions of Ontario. Increasing age, but not the presence of comorbidity, was associated with longer waiting times. Women who did not receive postoperative chemotherapy before RT for breast cancer waited significantly longer than all others. Measurement of waiting times for cancer RT must discount time during which adjuvant intravenous chemotherapy is administered after surgery and before RT. There appears to be a formal or informal process by which those at highest risk begin RT most rapidly.

  2. Alternatives for optimal hormone replacement therapy.

    Science.gov (United States)

    Sitruk-Ware, R

    2003-08-01

    To satisfy the needs of women with a wide variety of different medical histories and preferences, a wide choice of various forms of hormone replacement therapy (HRT) is desirable. The potential long-term benefits of HRT, in terms of osteoporosis, cardiovascular disease and dementia, require good compliance, which in turn requires an HRT formulation that is highly acceptable. An absence of weight gain and lack of androgenic effects are of great importance, as are predictable bleeding and positive effects on postmenopausal symptoms and quality of life. HRT should be tailored to each woman's needs by the choice of appropriate estrogens and particularly a progestogen with a suitable pharmacological profile. An ideal progestogen should be targeted at preventing endometrial hyperplasia without opposing the effects of estrogen on the vessels. Several new progestogens have been synthesized in recent years. Dienogest, the progestogenic component of a new hormone replacement therapy with estradiol valerate, has many desirable features, including antiandrogenic properties; in this respect, it is unique amongst progestogens derived from testosterone. Tailored HRT should treat symptoms, minimize risk factors, meet personal preferences and lifestyle needs, and not be contraindicated for concomitant diseases. During the next decade, optimal HRT must match a number of trends, including an aging population, and is likely to be influenced by the outcome of major trials such as the Women's Health Initiative trial whose negative results will impact the prescriptions, the advent of new compounds--particularly the selective estrogen receptor modulators and progestogen receptor modulators--and the introduction of new methods of delivery, including vaginal rings and medicated intrauterine systems.

  3. Automatic Organ Localization for Adaptive Radiation Therapy for Prostate Cancer

    National Research Council Canada - National Science Library

    Joshi, Sarang

    2004-01-01

    The focus of this study is adaptive radiation therapy (ART) for prostate cancer, in which the treatment is to be adjusted over time, based on CT images acquired on the treatment table before each daily treatment...

  4. Cardiac complications of radiation therapy. Complications cardiaques de la radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, E.; Baudouy, M.; Morand, P. (Hopital Pasteur, 06 - Nice (France)); Lagrange, J.L. (Centre de Lutte Contre le Cancer Antoine Lacassagne, 06 - Nice (France)); Taillan, B. (Hopital de Cimiez, 06 - Nice (France))

    1993-01-01

    In this article, the authors expose the possible cardiac complications following a radiation therapy: pericarditis, effects on ventricular function, coronary lesions, valvular lesions, electrocardiographic anomalies and pace-maker disfunction.

  5. Sensitivity analysis for lexicographic ordering in radiation therapy treatment planning

    Science.gov (United States)

    Long, T.; Matuszak, M.; Feng, M.; Fraass, B. A.; Ten Haken, R. K.; Romeijn, H. E.

    2012-01-01

    Purpose: To introduce a method to efficiently identify and calculate meaningful tradeoffs between criteria in an interactive IMRT treatment planning procedure. The method provides a systematic approach to developing high-quality radiation therapy treatment plans. Methods: Treatment planners consider numerous dosimetric criteria of varying importance that, when optimized simultaneously through multicriteria optimization, yield a Pareto frontier which represents the set of Pareto-optimal treatment plans. However, generating and navigating this frontier is a time-consuming, nontrivial process. A lexicographic ordering (LO) approach to IMRT uses a physician’s criteria preferences to partition the treatment planning decisions into a multistage treatment planning model. Because the relative importance of criteria optimized in the different stages may not necessarily constitute a strict prioritization, the authors introduce an interactive process, sensitivity analysis in lexicographic ordering (SALO), to allow the treatment planner control over the relative sequential-stage tradeoffs. By allowing this flexibility within a structured process, SALO implicitly restricts attention to and allows exploration of a subset of the Pareto efficient frontier that the physicians have deemed most important. Results: Improvements to treatment plans over a LO approach were found by implementing the SALO procedure on a brain case and a prostate case. In each stage, a physician assessed the tradeoff between previous stage and current stage criteria. The SALO method provided critical tradeoff information through curves approximating the relationship between criteria, which allowed the physician to determine the most desirable treatment plan. Conclusions: The SALO procedure provides treatment planners with a directed, systematic process to treatment plan selection. By following a physician’s prioritization, the treatment planner can avoid wasting effort considering clinically inferior

  6. The physical basis and future of radiation therapy

    OpenAIRE

    Bortfeld, T.; Jeraj, R

    2011-01-01

    The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more...

  7. Estimated radiation pneumonitis risk after photon versus proton therapy alone or combined with chemotherapy for lung cancer

    DEFF Research Database (Denmark)

    Vogelius, Ivan R.; Westerly, David C; Aznar, Marianne Camille

    2011-01-01

    Background. Traditionally, radiation therapy plans are optimized without consideration of chemotherapy. Here, we model the risk of radiation pneumonitis (RP) in the presence of a possible interaction between chemotherapy and radiation dose distribution. Material and methods. Three alternative...... highly conformal photon techniques may become relevant for lung toxicity when radiation is combined with cytotoxic chemotherapy as shown here. Proton therapy allows highly conformal delivery while minimizing the low dose bath potentially interacting with chemotherapy. Thus, intensive drug-radiation...... treatment plans are compared in 18 non-small cell lung cancer patients previously treated with helical tomotherapy; the tomotherapy plan, an intensity modulated proton therapy plan (IMPT) and a three dimensional conformal radiotherapy (3D-CRT) plan. All plans are optimized without consideration...

  8. Can radiation therapy treatment planning system accurately predict surface doses in postmastectomy radiation therapy patients?

    Science.gov (United States)

    Wong, Sharon; Back, Michael; Tan, Poh Wee; Lee, Khai Mun; Baggarley, Shaun; Lu, Jaide Jay

    2012-01-01

    Skin doses have been an important factor in the dose prescription for breast radiotherapy. Recent advances in radiotherapy treatment techniques, such as intensity-modulated radiation therapy (IMRT) and new treatment schemes such as hypofractionated breast therapy have made the precise determination of the surface dose necessary. Detailed information of the dose at various depths of the skin is also critical in designing new treatment strategies. The purpose of this work was to assess the accuracy of surface dose calculation by a clinically used treatment planning system and those measured by thermoluminescence dosimeters (TLDs) in a customized chest wall phantom. This study involved the construction of a chest wall phantom for skin dose assessment. Seven TLDs were distributed throughout each right chest wall phantom to give adequate representation of measured radiation doses. Point doses from the CMS Xio® treatment planning system (TPS) were calculated for each relevant TLD positions and results correlated. There were no significant difference between measured absorbed dose by TLD and calculated doses by the TPS (p > 0.05 (1-tailed). Dose accuracy of up to 2.21% was found. The deviations from the calculated absorbed doses were overall larger (3.4%) when wedges and bolus were used. 3D radiotherapy TPS is a useful and accurate tool to assess the accuracy of surface dose. Our studies have shown that radiation treatment accuracy expressed as a comparison between calculated doses (by TPS) and measured doses (by TLD dosimetry) can be accurately predicted for tangential treatment of the chest wall after mastectomy. Copyright © 2012 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  9. Pelvic Normal Tissue Contouring Guidelines for Radiation Therapy: A Radiation Therapy Oncology Group Consensus Panel Atlas

    Energy Technology Data Exchange (ETDEWEB)

    Gay, Hiram A., E-mail: hgay@radonc.wustl.edu [Washington University School of Medicine, St Louis, MO (United States); Barthold, H. Joseph [Commonwealth Hematology and Oncology, Weymouth, MA (United States); Beth Israel Deaconess Medical Center, Boston, MA (Israel); O' Meara, Elizabeth [Radiation Therapy Oncology Group, Philadelphia, PA (United States); Bosch, Walter R. [Washington University School of Medicine, St Louis, MO (United States); El Naqa, Issam [Department of Radiation Oncology, McGill University Health Center, Montreal, Quebec (Canada); Al-Lozi, Rawan [Washington University School of Medicine, St Louis, MO (United States); Rosenthal, Seth A. [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); Lawton, Colleen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Lee, W. Robert [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Sandler, Howard [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Zietman, Anthony [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Myerson, Robert [Washington University School of Medicine, St Louis, MO (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Willett, Christopher [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, MA (United States); Jhingran, Anuja [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Portelance, Lorraine [University of Miami, Miami, FL (United States); Ryu, Janice [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); and others

    2012-07-01

    Purpose: To define a male and female pelvic normal tissue contouring atlas for Radiation Therapy Oncology Group (RTOG) trials. Methods and Materials: One male pelvis computed tomography (CT) data set and one female pelvis CT data set were shared via the Image-Guided Therapy QA Center. A total of 16 radiation oncologists participated. The following organs at risk were contoured in both CT sets: anus, anorectum, rectum (gastrointestinal and genitourinary definitions), bowel NOS (not otherwise specified), small bowel, large bowel, and proximal femurs. The following were contoured in the male set only: bladder, prostate, seminal vesicles, and penile bulb. The following were contoured in the female set only: uterus, cervix, and ovaries. A computer program used the binomial distribution to generate 95% group consensus contours. These contours and definitions were then reviewed by the group and modified. Results: The panel achieved consensus definitions for pelvic normal tissue contouring in RTOG trials with these standardized names: Rectum, AnoRectum, SmallBowel, Colon, BowelBag, Bladder, UteroCervix, Adnexa{sub R}, Adnexa{sub L}, Prostate, SeminalVesc, PenileBulb, Femur{sub R}, and Femur{sub L}. Two additional normal structures whose purpose is to serve as targets in anal and rectal cancer were defined: AnoRectumSig and Mesorectum. Detailed target volume contouring guidelines and images are discussed. Conclusions: Consensus guidelines for pelvic normal tissue contouring were reached and are available as a CT image atlas on the RTOG Web site. This will allow uniformity in defining normal tissues for clinical trials delivering pelvic radiation and will facilitate future normal tissue complication research.

  10. Feasibility of prostate robotic radiation therapy on conventional C-arm linacs.

    Science.gov (United States)

    Dong, Peng; Nguyen, Dan; Ruan, Dan; King, Christopher; Long, Troy; Romeijn, Edwin; Low, Daniel A; Kupelian, Patrick; Steinberg, Michael; Yang, Yingli; Sheng, Ke

    2014-01-01

    Significant dosimetric improvement for radiation therapy using optimized noncoplanar fields has been previously demonstrated. The purpose here is to study the feasibility of optimized robotic noncoplanar radiation therapy, termed 4π therapy, for prostate cancer treatments on a conventional C-arm linac. Twelve low-risk prostate cancer patients previously treated by 2-arc volumetric modulated arc therapy (VMAT) were selected. Forty gray in 5 fractions were prescribed to cover 95% of the prostate planning target volume (PTV). To replan by 4π therapy, a column generation method was used to optimize beam orientations and fluence. A total of 30 beams were selected for each patient. Both planning methods provided adequate PTV coverage. Compared against VMAT plans, the 4π plan reduced the rectum V50%, V80%, V90%, D1cc, and the penile bulb maximum doses by 50%, 28%, 19% 11%, and 9% (P arm linac platform. Copyright © 2014 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  11. Low-Dose Pretreatment for Radiation Therapy

    OpenAIRE

    Blankenbecler, Richard

    2010-01-01

    In radiotherapy, a large radiation dose must be applied to both cancer and neighboring healthy cells. Recent experiments have shown that a low dose of ionizing radiation turns on certain protective mechanisms that allow a cell to better survive a subsequent high dose of radiation. This adaptive response can have important and positive consequences for radiotherapy. This paper describes a simple change in treatment procedures to make use of these beneficial effects. A low dose applied only to ...

  12. Therapy radiation apparatus for veterinary medicine

    Energy Technology Data Exchange (ETDEWEB)

    Parris, D.M.

    1987-03-03

    A radiation device is described for use in veterinary medicine, for treating exterior and interior portions of animal bodies, comprising: (a) power supply means providing selected voltages; (b) high frequency oscillator means; (c) frequency divider means responsive to the oscillator means, and adapted to control switch means for modulating a voltage supply for at least one non-laser broad band infrared radiation diode providing an expanding beam of radiation; and (d) means for applying at least one one-laser broad band infrared radiation diode to a dermal surface of an animal.

  13. Coronary artery calcium in breast cancer survivors after radiation therapy

    NARCIS (Netherlands)

    Takx, Richard A P; Vliegenthart, Rozemarijn; Schoepf, U Joseph; Pilz, Lothar R; Schoenberg, Stefan O; Morris, Pamela B; Henzler, Thomas; Apfaltrer, Paul

    The purpose of the current study is to investigate whether breast cancer survivors after radiation therapy have a higher burden of coronary artery calcium as a potential surrogate of radiation-induced accelerated coronary artery disease. 333 patients were included. 54 patients underwent chest CT ae

  14. Cranial Radiation Therapy and Damage to Hippocampal Neurogenesis

    Science.gov (United States)

    Monje, Michelle

    2008-01-01

    Cranial radiation therapy is associated with a progressive decline in cognitive function, prominently memory function. Impairment of hippocampal neurogenesis is thought to be an important mechanism underlying this cognitive decline. Recent work has elucidated the mechanisms of radiation-induced failure of neurogenesis. Potential therapeutic…

  15. Palliative radiation therapy for bone metastases: Update of an ASTRO Evidence-Based Guideline.

    Science.gov (United States)

    Lutz, Stephen; Balboni, Tracy; Jones, Joshua; Lo, Simon; Petit, Joshua; Rich, Shayna E; Wong, Rebecca; Hahn, Carol

    The purpose is to provide an update the Bone Metastases Guideline published in 2011 based on evidence complemented by expert opinion. The update will discuss new high-quality literature for the 8 key questions from the original guideline and implications for practice. A systematic PubMed search from the last date included in the original Guideline yielded 414 relevant articles. Ultimately, 20 randomized controlled trials, 32 prospective nonrandomized studies, and 4 meta-analyses/pooled analyses were selected and abstracted into evidence tables. The authors synthesized the evidence and reached consensus on the included recommendations. Available literature continues to support pain relief equivalency between single and multiple fraction regimens for bone metastases. High-quality data confirm single fraction radiation therapy may be delivered to spine lesions with acceptable late toxicity. One prospective, randomized trial confirms both peripheral and spine-based painful metastases can be successfully and safely palliated with retreatment for recurrence pain with adherence to published dosing constraints. Advanced radiation therapy techniques such as stereotactic body radiation therapy lack high-quality data, leading the panel to favor its use on a clinical trial or when results will be collected in a registry. The panel's conclusion remains that surgery, radionuclides, bisphosphonates, and kyphoplasty/vertebroplasty do not obviate the need for external beam radiation therapy. Updated data analysis confirms that radiation therapy provides excellent palliation for painful bone metastases and that retreatment is safe and effective. Although adherence to evidence-based medicine is critical, thorough expert radiation oncology physician judgment and discretion regarding number of fractions and advanced techniques are also essential to optimize outcomes when considering the patient's overall health, life expectancy, comorbidities, tumor biology, anatomy, previous treatment

  16. Prototype demonstration of radiation therapy planning code system

    Energy Technology Data Exchange (ETDEWEB)

    Little, R.C.; Adams, K.J.; Estes, G.P.; Hughes, L.S. III; Waters, L.S. [and others

    1996-09-01

    This is the final report of a one-year, Laboratory-Directed Research and Development project at the Los Alamos National Laboratory (LANL). Radiation therapy planning is the process by which a radiation oncologist plans a treatment protocol for a patient preparing to undergo radiation therapy. The objective is to develop a protocol that delivers sufficient radiation dose to the entire tumor volume, while minimizing dose to healthy tissue. Radiation therapy planning, as currently practiced in the field, suffers from inaccuracies made in modeling patient anatomy and radiation transport. This project investigated the ability to automatically model patient-specific, three-dimensional (3-D) geometries in advanced Los Alamos radiation transport codes (such as MCNP), and to efficiently generate accurate radiation dose profiles in these geometries via sophisticated physics modeling. Modem scientific visualization techniques were utilized. The long-term goal is that such a system could be used by a non-expert in a distributed computing environment to help plan the treatment protocol for any candidate radiation source. The improved accuracy offered by such a system promises increased efficacy and reduced costs for this important aspect of health care.

  17. Organ doses from radiation therapy in atomic bomb survivors.

    Science.gov (United States)

    Kato, K; Antoku, S; Kodama, K; Kawamura, S; Fujita, Y; Komatsu, K; Awa, A A

    2001-06-01

    Previous surveys of radiation therapy among the Life Span Study (LSS) population at the Radiation Effects Research Foundation (RERF) revealed that 1,670 (1.4%) of the LSS participants received radiation treatments before 1984. The data on therapeutic radiation doses are indispensable for studying the relationship between radiation treatments and subsequent cancer occurrences. In this study, the radiation treatments were reproduced experimentally to determine the scattered radiation doses. The experiments were conducted using a female human phantom and various radiation sources, including a medium-voltage X-ray machine and a (60)Co gamma-ray source. Doses were measured using thermoluminescence dosimetry and ionization chambers. Radiation doses were determined for the salivary glands, thyroid gland, breast, lung, stomach, colon, ovary and active bone marrow. The results have been used for documenting the organ doses received by patients in previous surveys. The contribution of therapeutic irradiation to the occurrence of chromosome aberrations was studied using data on doses to active bone marrow from both radiation treatments and atomic bomb exposures in 26 RERF Adult Health Study participants. The results suggest that radiation treatments contributed to a large part of their frequencies of stable-type chromosome aberrations. The therapeutic radiation doses determined in the present study are available for investigating the effects of therapeutic irradiation on the subsequent primary cancers among atomic bomb survivors who received radiation treatments.

  18. Once-Daily Radiation Therapy for Inflammatory Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Lindsay [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Harmsen, William [Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota (United States); Blanchard, Miran [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Goetz, Matthew [Division of Medical Oncology, Mayo Clinic, Rochester, Minnesota (United States); Jakub, James [Department of Surgery, Mayo Clinic, Rochester, Minnesota (United States); Mutter, Robert; Petersen, Ivy; Rooney, Jessica [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Stauder, Michael [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Yan, Elizabeth [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Laack, Nadia, E-mail: laack.nadia@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States)

    2014-08-01

    Purpose: Inflammatory breast cancer (IBC) is a rare and aggressive breast cancer variant treated with multimodality therapy. A variety of approaches intended to escalate the intensity and efficacy of radiation therapy have been reported, including twice-daily radiation therapy, dose escalation, and aggressive use of bolus. Herein, we examine our outcomes for patients treated with once-daily radiation therapy with aggressive bolus utilization, focusing on treatment technique. Methods and Materials: A retrospective review of patients with nonmetastatic IBC treated from January 1, 2000, through December 31, 2010, was performed. Locoregional control (LRC), disease-free survival (DFS), overall survival (OS) and predictors thereof were assessed. Results: Fifty-two women with IBC were identified, 49 (94%) of whom were treated with neoadjuvant chemotherapy. All underwent mastectomy followed by adjuvant radiation therapy. Radiation was delivered in once-daily fractions of 1.8 to 2.25 Gy (median, 2 Gy). Patients were typically treated with daily 1-cm bolus throughout treatment, and 33 (63%) received a subsequent boost to the mastectomy scar. Five-year Kaplan Meier survival estimates for LRC, DFS, and OS were 81%, 56%, and 64%, respectively. Locoregional recurrence was associated with poorer OS (P<.001; hazard ratio [HR], 4.1). Extracapsular extension was associated with worse LRC (P=.02), DFS (P=.007), and OS (P=.002). Age greater than 50 years was associated with better DFS (P=.03). Pathologic complete response was associated with a trend toward improved LRC (P=.06). Conclusions: Once-daily radiation therapy with aggressive use of bolus for IBC results in outcomes consistent with previous reports using various intensified radiation therapy regimens. LRC remains a challenge despite modern systemic therapy. Extracapsular extension, age ≤50 years, and lack of complete response to chemotherapy appear to be associated with worse outcomes. Novel strategies are needed in IBC

  19. SU-F-J-178: A Computer Simulation Model Observer for Task-Based Image Quality Assessment in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Dolly, S; Mutic, S; Anastasio, M; Li, H [Washington University School of Medicine, Saint Louis, MO (United States); Yu, L [Mayo Clinic, Rochester, MN (United States)

    2016-06-15

    Purpose: Traditionally, image quality in radiation therapy is assessed subjectively or by utilizing physically-based metrics. Some model observers exist for task-based medical image quality assessment, but almost exclusively for diagnostic imaging tasks. As opposed to disease diagnosis, the task for image observers in radiation therapy is to utilize the available images to design and deliver a radiation dose which maximizes patient disease control while minimizing normal tissue damage. The purpose of this study was to design and implement a new computer simulation model observer to enable task-based image quality assessment in radiation therapy. Methods: A modular computer simulation framework was developed to resemble the radiotherapy observer by simulating an end-to-end radiation therapy treatment. Given images and the ground-truth organ boundaries from a numerical phantom as inputs, the framework simulates an external beam radiation therapy treatment and quantifies patient treatment outcomes using the previously defined therapeutic operating characteristic (TOC) curve. As a preliminary demonstration, TOC curves were calculated for various CT acquisition and reconstruction parameters, with the goal of assessing and optimizing simulation CT image quality for radiation therapy. Sources of randomness and bias within the system were analyzed. Results: The relationship between CT imaging dose and patient treatment outcome was objectively quantified in terms of a singular value, the area under the TOC (AUTOC) curve. The AUTOC decreases more rapidly for low-dose imaging protocols. AUTOC variation introduced by the dose optimization algorithm was approximately 0.02%, at the 95% confidence interval. Conclusion: A model observer has been developed and implemented to assess image quality based on radiation therapy treatment efficacy. It enables objective determination of appropriate imaging parameter values (e.g. imaging dose). Framework flexibility allows for incorporation

  20. Development of medical application methods using radiation. Radionuclide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chang Woon; Lim, S. M.; Kim, E.H.; Woo, K. S.; Chung, W. S.; Lim, S. J.; Choi, T. H.; Hong, S. W.; Chung, H. Y.; No, W. C. [Korea Atomic Energy Research Institute. Korea Cancer Center Hospital, Seoul, (Korea, Republic of); Oh, B. H. [Seoul National University. Hospital, Seoul (Korea, Republic of); Hong, H. J. [Antibody Engineering Research Unit, Taejon (Korea, Republic of)

    1999-04-01

    In this project, we studied following subjects: 1. development of monoclonal antibodies and radiopharmaceuticals 2. clinical applications of radionuclide therapy 3. radioimmunoguided surgery 4. prevention of restenosis with intracoronary radiation. The results can be applied for the following objectives: (1) radionuclide therapy will be applied in clinical practice to treat the cancer patients or other diseases in multi-center trial. (2) The newly developed monoclonal antibodies and biomolecules can be used in biology, chemistry or other basic life science research. (3) The new methods for the analysis of therapeutic effects, such as dosimetry, and quantitative analysis methods of radioactivity, can be applied in basic research, such as radiation oncology and radiation biology.

  1. [Ozone therapy for radiation reactions and skin lesions after neutron therapy in patients with malignant tumors].

    Science.gov (United States)

    Velikaya, V V; Gribova, O V; Musabaeva, L I; Startseva, Zh A; Simonov, K A; Aleinik, A N; Lisin, V A

    2015-01-01

    The article discusses the problem of radiation complications from normal tissues in patients after therapy with fast neutrons of 6.3 MeV. The methods of treatment using ozone technologies in patients with radiation reactions and skin lesions on the areas of irradiation after neutron and neutron-photon therapy have been worked out. Ozone therapy showed its harmlessness and increased efficiency of complex treatment of these patients.

  2. 21 CFR 892.5050 - Medical charged-particle radiation therapy system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical charged-particle radiation therapy system...-particle radiation therapy system. (a) Identification. A medical charged-particle radiation therapy system...) intended for use in radiation therapy. This generic type of device may include signal analysis and display...

  3. [The application of total quality management (TQM) in quality management of radiation therapy].

    Science.gov (United States)

    Jiang, Rui-yao; Fu, Shen; Li, Bin

    2009-03-01

    The strategies and methods of the total quality management (TQM) need to applied in quality management of radiation therapy. We should improve the level of quality control and quality assurance in radiation therapy. By establishing quality control system in radiation therapy, standardization of radiation therapy workflow, strengthening quality control of devices and physical technique and paying attention to safety protection and staff training.

  4. Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

    Science.gov (United States)

    Bednarz, Bryan; Besemer, Abigail

    2017-09-01

    The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

  5. Results of Radiation Therapy in Stage III Uterine Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Chang Woo; Shin, Byung Chul; Yum, Ha Yong; Jeung, Tae Sig; Yoo, Myung Jin [Kosin University College of Medicine, Seoul (Korea, Republic of)

    1995-09-15

    Purpose : The aim of this study is to analyze the survival rate, treatment failure and complication of radiation therapy alone in stage III uterine cervical cancer. Materials and Methods : From January 1980 through December 1985, 227 patients with stage II uterine cervical cancer treated with radiation therapy at Kosin Medical Center were retrospectively studied. Among 227 patients, 72 patients(31.7%) were stage IIIa, and 155 patients(68.3%) were stage IIIb according to FIGO classification. Age distribution was 32-71 years(median: 62 years). Sixty nine patients(95.8%) in stage IIIa and 150 patients(96.8%) in stage IIIb were squamous cell carcinoma. Pelvic lymph node metastasis at initial diagnosis was 8 patients (11.1%) in stage IIIa and 29 patients(18.7%) in stage IIIb. Among 72 patients with stage IIIa, 36 patients(50%) were treated with external radiation therapy alone by conventional technique (180-200 cGy/fr). And 36 patients(50%) were treated with external radiation therapy with intracavitary radiotherapy(ICR) with Cs137 sources, and among 155 patients with stage IIIb, 80 patients(51.6%) were treated with external radiation therapy alone and 75 patients(48.4%) were treated with external radiation therapy with ICR. Total radiation doses of stage IIIa and IIIb were 65-105 Gy(median : 78.5 Gy) and 65-125.5 Gy (median :83.5 Gy). Survival rate was calculated by life-table method. Results : Complete response rates were 58.3% (42 patients) in state IIIa and 56.1%(87 patients) in stage Iiib. Overall 5 year survival rates were 57% in stage IIIa and 40% in stage IIIb. Five year survival rates by radiation technique in stage IIIa and IIIb were 64%, 40% in group treated in combination of external radiation and ICR, and 50%, 40% in the group of external radiation therapy alone(P=NS). Five year survival rates by response of radiation therapy in stage IIIa and IIIb were 90%, 66% in responder group, and 10%, 7% in non-responder group (P<0.01). There were statistically no

  6. Hyperbaric oxygen therapy for radiation-induced hemorrhagic cystitis

    Energy Technology Data Exchange (ETDEWEB)

    Miyazato, Tomonori; Yusa, Toshiko; Onaga, Tomohiro; Sugaya, Kimio; Koyama, Yuzo; Hatano, Tadashi; Ogawa, Yoshihide [Ryukyus Univ., Nishihara, Okinawa (Japan). Faculty of Medicine

    1998-05-01

    Radiation therapy has widely been used for cancers in the pelvis. Radiation cystitis, one of the late complications, presents often as hemorrhagic cystitis, which is refractory to the conventional therapy and may threaten the patient`s life. We used hyperbaric oxygen therapy on patients with radiation cystitis to test its potential benefit. Ten patients aged from 46 to 81 years with a mean of 62 years underwent one or more courses of hyperbaric oxygen therapy according to their symptoms, consisting of 20 sessions (3 to 5 sessions a week) at the Department of Hyperbaric Medicine, the University of the Ryukyus Hospital in the 9-year period from 1985 to 1994. They included 8 patients having a history of cervical cancer, one with external genital cancer and one with vaginal cancer. During the 75 min hyperbaric oxygen therapy patients received 100% oxygen at 2 absolute atmosphere pressure in the Multiplace Hyperbaric Chamber. Hematuria subsided and subjective symptoms including urinary frequency improved in seven patients. Cystoscopic findings including mucosal edema, redness, and capillary dilation were partially improved. The procedure subjectively and objectively palliated the 10 patients in a favorable manner. To date we have not armed any active procedure to control radiation-induced refractory hemorrhagic cystitis in terms of efficacy, invasiveness, and adverse effects. Therefore, in consideration of our clinical results, hyperbaric oxygen therapy appears to be useful for radiation cystitis. (author)

  7. Music therapy CD creation for initial pediatric radiation therapy: a mixed methods analysis.

    Science.gov (United States)

    Barry, Philippa; O'Callaghan, Clare; Wheeler, Greg; Grocke, Denise

    2010-01-01

    A mixed methods research design was used to investigate the effects of a music therapy CD (MTCD) creation intervention on pediatric oncology patients' distress and coping during their first radiation therapy treatment. The music therapy method involved children creating a music CD using interactive computer-based music software, which was "remixed" by the music therapist-researcher to extend the musical material. Eleven pediatric radiation therapy outpatients aged 6 to 13 years were randomly assigned to either an experimental group, in which they could create a music CD prior to their initial treatment to listen to during radiation therapy, or to a standard care group. Quantitative and qualitative analyses generated multiple perceptions from the pediatric patients, parents, radiation therapy staff, and music therapist-researcher. Ratings of distress during initial radiation therapy treatment were low for all children. The comparison between the two groups found that 67% of the children in the standard care group used social withdrawal as a coping strategy, compared to 0% of the children in the music therapy group; this trend approached significance (p = 0.076). MTCD creation was a fun, engaging, and developmentally appropriate intervention for pediatric patients, which offered a positive experience and aided their use of effective coping strategies to meet the demands of their initial radiation therapy treatment.

  8. Radiation Therapy for Neovascular Age-related Macular Degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Kishan, Amar U. [Harvard Medical School, Boston, Massachusetts (United States); Modjtahedi, Bobeck S.; Morse, Lawrence S. [Department of Ophthalmology and Vision Sciences, University of California, Davis, Sacramento, California (United States); Lee, Percy, E-mail: percylee@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California (United States)

    2013-03-01

    In the enormity of the public health burden imposed by age-related macular degeneration (ARMD), much effort has been directed toward identifying effective and efficient treatments. Currently, anti-vascular endothelial growth factor (VEGF) injections have demonstrated considerably efficacy in treating neovascular ARMD, but patients require frequent treatment to fully benefit. Here, we review the rationale and evidence for radiation therapy of ARMD. The results of early photon external beam radiation therapy are included to provide a framework for the sequential discussion of evidence for the usage of stereotactic radiation therapy, proton therapy, and brachytherapy. The evidence suggests that these 3 modern modalities can provide a dose-dependent benefit in the treatment of ARMD. Most importantly, preliminary data suggest that all 3 can be used in conjunction with anti-VEGF therapeutics, thereby reducing the frequency of anti-VEGF injections required to maintain visual acuity.

  9. Optimization of Transient Response Radiation of Printed Ultra Wideband Dipole Antennas (Using Particle Swarm Optimization Method

    Directory of Open Access Journals (Sweden)

    M. Mazanek

    2007-06-01

    Full Text Available In case of particular ultra wideband applications (i.e. radar, positioning, etc., it is crucial to know the transient responses of antennas. In the first part of the paper, the optimization process searches for the dipole shape that accomplishes two required parameters i.e. a good matching and a minimal distortion. The particle swarm optimization method was used in the process of the dipole shape optimization. As a result, the optimized ultra wideband dipole is perfectly matched. Moreover, it minimally distorts the applied signal. The second part of the paper discusses the influence of the feeding circuit on radiating parameters and on the dipole antenna matching.

  10. Stereotactic body radiation therapy versus conventional radiation therapy in patients with early stage non-small cell lung cancer

    DEFF Research Database (Denmark)

    Jeppesen, Stefan Starup; Schytte, Tine; Jensen, Henrik R

    2013-01-01

    Abstract Introduction. Stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) is now an accepted and patient friendly treatment, but still controversy exists about its comparability to conventional radiation therapy (RT). The purpose of this single...... and SBRT predicted improved prognosis. However, staging procedure, confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes. However, SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients....

  11. DESIGN OF MICROSTRIP RADIATOR USING PARTICLE SWARM OPTIMIZATION TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Yogesh Kumar Choukiker

    2011-09-01

    Full Text Available An inset feed Microstrip radiator has been designed and developed for operation at 2.4GHz frequency. The Microstrip patch antenna (MPA parameters were designed using IE3D®TM EM simulator (version 14.0 and optimized with an evolutionary stochastic optimizer i.e. Particle Swarm Optimization (PSO technique. Optimized results show that the antenna has a bandwidth of 33.54 MHz (<-10dB in the range 2.38355 GHz to 2.41709 GHz and a maximum return loss of -43.87dB at the resonant frequency of 2.4 GHz. The patch antenna is fabricated and the important parameters like return loss, VSWR etc were measured. The measured parameters match with the simulated results well within the tolerable limits.

  12. Risk-optimized proton therapy to minimize radiogenic second cancers

    DEFF Research Database (Denmark)

    Rechner, Laura A; Eley, John G; Howell, Rebecca M

    2015-01-01

    Proton therapy confers substantially lower predicted risk of second cancer compared with photon therapy. However, no previous studies have used an algorithmic approach to optimize beam angle or fluence-modulation for proton therapy to minimize those risks. The objectives of this study were...... to demonstrate the feasibility of risk-optimized proton therapy and to determine the combination of beam angles and fluence weights that minimizes the risk of second cancer in the bladder and rectum for a prostate cancer patient. We used 6 risk models to predict excess relative risk of second cancer. Treatment...

  13. Technical basis of radiation therapy. Practical clinical applications. 5. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Levitt, Seymour H. [Karolinska Institutet Stockholm (Sweden). Dept. of Oncol-Pathol; Perez, Carlos A. [Washington Univ. Medical Center, St. Louis, MO (United States). Dept. of Radiation Oncology; Purdy, James A. [California Univ., Sacramento, CA (United States). Dept. of Radiation Oncology; Poortmans, Philip [Institute Verbeeten, Tilburg (Netherlands). Dept. of Radiation Oncology

    2012-07-01

    This well-received book, now in its fifth edition, is unique in providing a detailed description of the technological basis of radiation therapy. Another novel feature is the collaborative writing of the chapters by North American and European authors. This considerably broadens the book's perspective and increases its applicability in daily practice throughout the world. The book is divided into two sections. The first covers basic concepts in treatment planning, including essential physics and biological principles related to time-dose-fractionation, and explains the various technological approaches to radiation therapy, such as intensity-modulated radiation therapy, tomotherapy, stereotactic radiotherapy, and high and low dose rate brachytherapy. Issues relating to quality assurance, technology assessment, and cost-benefit analysis are also reviewed. The second part of the book discusses in depth the practical clinical applications of the different radiation therapy techniques in a wide range of cancer sites. All of the chapters have been written by leaders in the field. This book will serve to instruct and acquaint teachers, students, and practitioners in the various fields of oncology with the basic technological factors and approaches in radiation therapy. (orig.)

  14. Technological progress in radiation therapy for brain tumors

    LENUS (Irish Health Repository)

    Vernimmen, Frederik Jozef

    2014-01-01

    To achieve a good therapeutic ratio the radiation dose to the tumor should be as high as possible with the lowest possible dose to the surrounding normal tissue. This is especially the case for brain tumors. Technological ad- vancements in diagnostic imaging, dose calculations, and radiation delivery systems, combined with a better un- derstanding of the pathophysiology of brain tumors have led to improvements in the therapeutic results. The widely used technology of delivering 3-D conformal therapy with photon beams (gamma rays) produced by Li-near Accelerators has progressed into the use of Intensity modulated radiation therapy (IMRT). Particle beams have been used for several decades for radiotherapy because of their favorable depth dose characteristics. The introduction of clinically dedicated proton beam therapy facilities has improved the access for cancer patients to this treatment. Proton therapy is of particular interest for pediatric malignancies. These technical improvements are further enhanced by the evolution in tumor physiology imaging which allows for improved delineation of the tumor. This in turn opens the potential to adjust the radiation dose to maximize the radiobiological effects. The advances in both imaging and radiation therapy delivery will be discussed.

  15. Deformable image registration in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seung Jong; Kim, Si Yong [Dept. of Radiation Oncology, Virginia Commonwealth University, Richmond (United States)

    2017-06-15

    The number of imaging data sets has significantly increased during radiation treatment after introducing a diverse range of advanced techniques into the field of radiation oncology. As a consequence, there have been many studies proposing meaningful applications of imaging data set use. These applications commonly require a method to align the data sets at a reference. Deformable image registration (DIR) is a process which satisfies this requirement by locally registering image data sets into a reference image set. DIR identifies the spatial correspondence in order to minimize the differences between two or among multiple sets of images. This article describes clinical applications, validation, and algorithms of DIR techniques. Applications of DIR in radiation treatment include dose accumulation, mathematical modeling, automatic segmentation, and functional imaging. Validation methods discussed are based on anatomical landmarks, physical phantoms, digital phantoms, and per application purpose. DIR algorithms are also briefly reviewed with respect to two algorithmic components: similarity index and deformation models.

  16. Modern radiation therapy for extranodal lymphomas

    DEFF Research Database (Denmark)

    Yahalom, Joachim; Illidge, Tim; Specht, Lena

    2015-01-01

    adopted RT volume definitions based on the International Commission on Radiation Units and Measurements (ICRU), as has been widely adopted by the field of radiation oncology for solid tumors. Organ-specific recommendations take into account histological subtype, anatomy, the treatment intent, and other......, involving any organ in the body and the spectrum of histological sub-types, poses a challenge both for routine clinical care and for the conduct of prospective and retrospective studies. This has led to uncertainty and lack of consistency in RT approaches between centers and clinicians. Thus far...

  17. Communication skills training for radiation therapists: preparing patients for radiation therapy.

    Science.gov (United States)

    Halkett, Georgia; O'Connor, Moira; Aranda, Sanchia; Jefford, Michael; Merchant, Susan; York, Debra; Miller, Lisa; Schofield, Penelope

    2016-12-01

    Patients sometimes present for radiation therapy with high levels of anxiety. Communication skills training may assist radiation therapists to conduct more effective consultations with patients prior to treatment planning and treatment commencement. The overall aim of our research is to examine the effectiveness of a preparatory programme 'RT Prepare' delivered by radiation therapists to reduce patient psychological distress. The purpose of this manuscript was to describe the communication skills workshops developed for radiation therapists and evaluate participants' feedback. Radiation therapists were invited to participate in two communication skills workshops run on the same day: (1) Consultation skills in radiation therapy and (2) Eliciting and responding to patients' emotional cues. Evaluation forms were completed. Radiation therapists' consultations with patients were then audio-recorded and evaluated prior to providing a follow-up workshop with participants. Nine full day workshops were held. Sixty radiation therapists participated. Positive feedback was received for both workshops with 88% or more participants agreeing or strongly agreeing with all the statements about the different components of the two workshops. Radiation therapists highlighted participating in role play with an actor, discussing issues; receiving feedback; acquiring new skills and knowledge; watching others role play and practicing with checklist were their favourite aspects of the initial workshop. The follow-up workshops provided radiation therapists with feedback on how they identified and addressed patients' psychological concerns; time spent with patients during consultations and the importance of finding private space for consultations. Communication skills training consisting of preparing patients for radiation therapy and eliciting and responding to emotional cues with follow-up workshops has the potential to improve radiation therapists' interactions with patients undergoing

  18. Optical tomography for measuring dose distribution in radiation therapy

    Directory of Open Access Journals (Sweden)

    Kauppinen Matti

    2014-01-01

    Full Text Available The dosimetry is used to verify the dose magnitude with artificial samples (phantoms before giving the planned radiation therapy to the patient. Typically, dose distribution is measured only in a single point or on a two-dimensional matrix plane. New techniques of radiation therapy ensure more detailed planning of radiation dose distribution which will lead to the need of measuring the radiation dose distribution three-dimensionally. The gel dosimetry is used to indicate and determine the ionizing radiation three-dimensionally. The radiation causes changes in chemical properties of the gel. The radiation dose distribution is defined by measuring the chemical changes. A conventional method is the magnetic resonance imaging and a new possibility is optical computed tomography (optical-CT. The optical-CT is much cheaper and more practical than magnetic resonance imaging. In this project, an optical-CT based method device was built by aiming at low material costs and a simple realization. The constructed device applies the charge coupled device camera and fluorescent lamp technologies. The test results show that the opacity level of the radiated gel can be measured accurately enough. The imaging accuracy is restricted by the optical distortion, e. g. vignetting, of the lenses, the distortion of a fluorescent lamp as the light source and a noisy measuring environment.

  19. Determinants of job satisfaction among radiation therapy faculty.

    Science.gov (United States)

    Swafford, Larry G; Legg, Jeffrey S

    2009-01-01

    Job satisfaction is one of the most significant predictors of employee retention in a variety of occupational settings, including health care and education. A national survey of radiation therapy educators (n = 90) has indicated that respondents are not satisfied with their jobs based on data collected using the Minnesota Satisfaction Questionnaire (MSQ). To predict the factors associated with job satisfaction or dissatisfaction, the authors used a nine-item questionnaire derived from the MSQ. Educators were grouped according to their job satisfaction scores, and multiple discriminant analysis was used to determine which factors were predictive of satisfaction among groups of educators. Statistical results indicate that ability utilization, institutional support, compensation, personnel, and job characteristics were key determinants of job satisfaction among radiation therapy educators. These results may better inform faculty and administration of important factors that can promote job satisfaction and retain faculty in radiation therapy education programs.

  20. Hypofractionated radiation therapy versus conventional radiation therapy in prostate cancer: A systematic review of its safety and efficacy.

    Science.gov (United States)

    Sánchez-Gómez, L M; Polo-deSantos, M; Rodríguez-Melcón, J I; Angulo, J C; Luengo-Matos, S

    2015-01-01

    New therapeutic alternatives can improve the safety and efficacy of prostate cancer treatment. To assess whether hypofractionated radiation therapy results in better safety and efficacy in the treatment of prostate cancer. Systematic review of the literature through searches on PubMed, Cochrane Library, CRD, ClinicalTrials and EuroScan, collecting indicators of safety and efficacy. We included 2 systematic reviews and a clinical trial. In terms of efficacy, there is considerable heterogeneity among the studies, and no conclusive results were found concerning the superiority of the hypofractionated option over the normal fractionated option. In terms of safety, there were no significant differences in the onset of acute genitourinary complications between the 2 treatments. However, one of the reviews found more acute gastrointestinal complications in patients treated with hypofractionated radiation therapy. There were no significant differences in long-term complications based on the type of radiation therapy used, although the studies did have limitations. To date, there are no conclusive results that show that hypofractionated radiation therapy is more effective or safer than normal fractionated radiation therapy in the treatment of localized prostate cancer. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Current status of radiation therapy. Evidence-based medicine (EBM) of radiation therapy. Non-small cell lung cancer (NSCLC)

    Energy Technology Data Exchange (ETDEWEB)

    Sumi, Minako [National Cancer Center, Tokyo (Japan). Hospital

    2002-04-01

    The goal of radiation therapy for non-small cell lung cancer (NSCLC) is to improve the survival rate of patients without increasing treatment-related toxicity and to improve patients' quality of life. Several prospective randomized trials have demonstrated a survival advantage in combined modality treatment over radiotherapy or chemotherapy alone when a cisplatin-based chemotherapy regimen is utilized in the treatment plan. Combined modality treatment of cisplatin-based chemotherapy and radiotherapy is standard treatment for selected patients such as those with better performance status with locally or regionally advanced lung cancer including T3-T4 or N2-N3. Determining the contribution of new agents in combined modality treatment will require carefully designed and conducted clinical trials. High-dose involved field radiation therapy using 3D-conformal radiation therapy potentially enables the use of higher doses than standard radiation therapy, because less normal tissue is irradiated, and may improve local control and survival. The combination of radiotherapy with chemotherapy and dose escalation using 3D-conformal radiation therapy is also a possibility in unresectable NSCLC. In surgery cases, the results of several Phase III trials of cisplatin-based preoperative chemotherapy have suggested survival improvement. But the concept needs to be tested in a larger Phase III trial. (author)

  2. Cost-Effectiveness of Surgery, Stereotactic Body Radiation Therapy, and Systemic Therapy for Pulmonary Oligometastases

    Energy Technology Data Exchange (ETDEWEB)

    Lester-Coll, Nataniel H., E-mail: nataniel.lester-coll@yale.edu [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Rutter, Charles E.; Bledsoe, Trevor J. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Goldberg, Sarah B. [Department of Medicine (Medical Oncology), Yale University School of Medicine, New Haven, Connecticut (United States); Decker, Roy H.; Yu, James B. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States)

    2016-06-01

    Introduction: Pulmonary oligometastases have conventionally been managed with surgery and/or systemic therapy. However, given concerns about the high cost of systemic therapy and improvements in local treatment of metastatic cancer, the optimal cost-effective management of these patients is unclear. Therefore, we sought to assess the cost-effectiveness of initial management strategies for pulmonary oligometastases. Methods and Materials: A cost-effectiveness analysis using a Markov modeling approach was used to compare average cumulative costs, quality adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) among 3 initial disease management strategies: video-assisted thoracic surgery (VATS) wedge resection, stereotactic body radiation therapy (SBRT), and systemic therapy among 5 different cohorts of patient disease: (1) melanoma; (2) non-small cell lung cancer adenocarcinoma without an EGFR mutation (NSCLC AC); (3) NSCLC with an EGFR mutation (NSCLC EGFRm AC); (4) NSCLC squamous cell carcinoma (NSCLC SCC); and (5) colon cancer. One-way sensitivity analyses and probabilistic sensitivity analyses were performed to analyze uncertainty with regard to model parameters. Results: In the base case, SBRT was cost effective for melanoma, with costs/net QALYs of $467,787/0.85. In patients with NSCLC, the most cost-effective strategies were SBRT for AC ($156,725/0.80), paclitaxel/carboplatin for SCC ($123,799/0.48), and erlotinib for EGFRm AC ($147,091/1.90). Stereotactic body radiation therapy was marginally cost-effective for EGFRm AC compared to erlotinib with an incremental cost-effectiveness ratio of $126,303/QALY. For colon cancer, VATS wedge resection ($147,730/2.14) was the most cost-effective strategy. Variables with the greatest influence in the model were erlotinib-associated progression-free survival (EGFRm AC), toxicity (EGFRm AC), cost of SBRT (NSCLC SCC), and patient utilities (all histologies). Conclusions: Video-assisted thoracic

  3. The physical basis and future of radiation therapy

    Science.gov (United States)

    Bortfeld, T; Jeraj, R

    2011-01-01

    The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued “fuelling” of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more “professionalism” in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics. PMID:21606068

  4. The physical basis and future of radiation therapy.

    Science.gov (United States)

    Bortfeld, T; Jeraj, R

    2011-06-01

    The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued "fuelling" of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more "professionalism" in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics.

  5. Synchrotron Radiation Therapy from a Medical Physics point of view

    Science.gov (United States)

    Prezado, Y.; Adam, J. F.; Berkvens, P.; Martinez-Rovira, I.; Fois, G.; Thengumpallil, S.; Edouard, M.; Vautrin, M.; Deman, P.; Bräuer-Krisch, E.; Renier, M.; Elleaume, H.; Estève, F.; Bravin, A.

    2010-07-01

    Synchrotron radiation (SR) therapy is a promising alternative to treat brain tumors, whose management is limited due to the high morbidity of the surrounding healthy tissues. Several approaches are being explored by using SR at the European Synchrotron Radiation Facility (ESRF), where three techniques are under development Synchrotron Stereotactic Radiation Therapy (SSRT), Microbeam Radiation Therapy (MRT) and Minibeam Radiation Therapy (MBRT). The sucess of the preclinical studies on SSRT and MRT has paved the way to clinical trials currently in preparation at the ESRF. With this aim, different dosimetric aspects from both theoretical and experimental points of view have been assessed. In particular, the definition of safe irradiation protocols, the beam energy providing the best balance between tumor treatment and healthy tissue sparing in MRT and MBRT, the special dosimetric considerations for small field dosimetry, etc will be described. In addition, for the clinical trials, the definition of appropiate dosimetry protocols for patients according to the well established European Medical Physics recommendations will be discussed. Finally, the state of the art of the MBRT technical developments at the ESRF will be presented. In 2006 A. Dilmanian and collaborators proposed the use of thicker microbeams (0.36-0.68 mm). This new type of radiotherapy is the most recently implemented technique at the ESRF and it has been called MBRT. The main advantage of MBRT with respect to MRT is that it does not require high dose rates. Therefore it can be more easily applied and extended outside synchrotron sources in the future.

  6. Current status of radiation therapy. Evidence-based medicine (EBM) of radiation therapy. Current management of patients with esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Kenji [Tohoku Univ., Sendai (Japan). School of Medicine

    2002-03-01

    The best management for small mucosal esophageal cancer is generally endoscopic mucosal resection. However, for submucosal cancer and extensive mucosal caner, either radical surgery or radiation seems to be an equally efficacious option. Radiation therapy concurrent with chemotherapy is more effective than radiation therapy alone for patients with unresectable esophageal cancer. The key drugs are cisplatin and 5-fluorouracil. However, for patients with poor performance status or for aged patients, radiation therapy alone is still a choice of treatment. Surgery has generally been indicated for patients with resectable esophageal cancer. However, outcomes of concurrent chemoradiation therapy may be comparable with those of surgery. Therefore, a prospective randomized study should be performed to determine the best management for patients with resectable esophageal cancer. The usefulness of intra-cavitary irradiation for esophageal cancer has not been clarified. A prospective randomized trial with a large number of patients is necessary to determine the effectiveness of intra-cavitary irradiation. The best management for patients with loco-regionally recurrent esophageal cancer after surgery has not been determined. Intensive therapy should be considered if the site of recurrence is limited and the time interval from surgery to recurrence is long. Chemotherapy is essential in the management of patients with small cell esophageal cancer. However, the best local therapy has not been determined. (author)

  7. Complications of head and neck radiation therapy and their management

    Energy Technology Data Exchange (ETDEWEB)

    Engelmeier, R.L.; King, G.E.

    1983-04-01

    Patients who receive radiation therapy to the head and neck suffer potential complications and undesirable side-effects of this therapy. The extent of undesirable responses is dependent on the source of irradiation, the fields of irradiation, and the dose. The radiotherapist determines these factors by the extent, location, and radiosensitivity of the tumor. The potential undesirable side-effects are xerostomia, mucositis, fibrosis, trismus, dermatitis, photosensitivity, radiation caries, soft tissue necrosis, and osteoradionecrosis. Each of these clinical entities and their proposed management have been discussed.

  8. Khan's lectures handbook of the physics of radiation therapy

    CERN Document Server

    Khan, Faiz M; Mihailidis, Dimitris

    2011-01-01

    Khan's Lectures: Handbook of the Physics of Radiation Therapy will provide a digest of the material contained in The Physics of Radiation Therapy. Lectures will be presented somewhat similar to a PowerPoint format, discussing key points of individual chapters. Selected diagrams from the textbook will be used to initiate the discussion. New illustrations will used, wherever needed, to enhance the understanding of important concepts. Discussion will be condensed and often bulleted. Theoretical details will be referred to the textbook and the cited literature. A problem set (practice questions) w

  9. Radiation therapy planning with photons and protons for early and advanced breast cancer: an overview

    Directory of Open Access Journals (Sweden)

    Lomax Antony J

    2006-07-01

    Full Text Available Abstract Postoperative radiation therapy substantially decreases local relapse and moderately reduces breast cancer mortality, but can be associated with increased late mortality due to cardiovascular morbidity and secondary malignancies. Sophistication of breast irradiation techniques, including conformal radiotherapy and intensity modulated radiation therapy, has been shown to markedly reduce cardiac and lung irradiation. The delivery of more conformal treatment can also be achieved with particle beam therapy using protons. Protons have superior dose distributional qualities compared to photons, as dose deposition occurs in a modulated narrow zone, called the Bragg peak. As a result, further dose optimization in breast cancer treatment can be reasonably expected with protons. In this review, we outline the potential indications and benefits of breast cancer radiotherapy with protons. Comparative planning studies and preliminary clinical data are detailed and future developments are considered.

  10. Determinants of Optimal Adherence to Antiretroviral Therapy among ...

    African Journals Online (AJOL)

    SITWALA COMPUTERS

    Determinants of Optimal Adherence to Antiretroviral. Therapy among People Living With HIV/AIDS. Registered for Antiretroviral Therapy in Zimbabwe. 1. 2. L Gonah , A Mukwirimba .... and Shona (native language in Masvingo province) language speakers trained on quantitative research methodology participated in data ...

  11. Radiation-induced pseudotumor following therapy for soft tissue sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Lacey F.; Kransdorf, Mark J. [Mayo Clinic, Department of Radiology, Jacksonville, FL (United States); Buskirk, Steven J. [Mayo Clinic, Department of Radiation Oncology, Jacksonville, FL (United States); O' Connor, Mary I. [Mayo Clinic, Department of Orthopedic Surgery, Jacksonville, FL (United States); Menke, David M. [Mayo Clinic, Department of Pathology, Jacksonville, FL (United States)

    2009-06-15

    The purpose of this study was to describe the prevalence and imaging appearance of radiation induced pseudotumors in patients following radiation therapy for extremity soft tissue sarcomas. We retrospectively reviewed the serial magnetic resonance (MR) images of 24 patients following radiation therapy for extremity soft tissue sarcomas. A total of 208 exams were reviewed (mean, 8.7 exams per patient) and included all available studies following the start of radiation therapy. Exams were analyzed for the identification of focal signal abnormalities within the surgical bed suggesting local tumor recurrence. Histopathologic correlation was available in nine patients suspected of having local tumor recurrence. Additional information recorded included patient demographics, tumor type and location, radiation type, and dose. The study group consisted of 12 men and 12 women, having an average age of 63 years (range, 39-88 years). Primary tumors were malignant fibrous histiocytoma (n = 13), leiomyosarcoma (n = 6), liposarcoma (n = 3), synovial sarcoma (n = 1), and extraskeletal chondrosarcoma (n = 1). All lesions were high-grade sarcomas, except for two myxoid liposarcomas. Average patient radiation dose was 5,658 cGy (range, 4,500-8,040 cGy). Average follow-up time was 63 months (range, 3-204 months). Focal signal abnormalities suggesting local recurrence were seen in nine (38%) patients. Three of the nine patients with these signal abnormalities were surgically proven to have radiation-induced pseudotumor. The pseudotumors developed between 11 and 61 months following the initiation of radiation therapy (mean, 38 months), with an average radiation dose of 5,527 cGy (range, 5,040-6,500 cGy). MR imaging demonstrated a relatively ill-defined ovoid focus of abnormal signal and intense heterogeneous enhancement with little or no associated mass effect. MR imaging of radiation-induced pseudotumor typically demonstrates a relatively ill-defined ovoid mass-like focus of intense

  12. Immunomodulatory effects of radiation: what is next for cancer therapy?

    Science.gov (United States)

    Kumari, Anita; Simon, Samantha S; Moody, Tomika D; Garnett-Benson, Charlie

    2016-01-01

    Despite its former reputation as being immunosuppressive, it has become evident that radiation therapy can enhance antitumor immune responses. This quality can be harnessed by utilizing radiation as an adjuvant to cancer immunotherapies. Most studies combine the standard radiation dose and regimens indicated for the given disease state, with novel cancer immunotherapies. It has become apparent that low-dose radiation, as well as doses within the hypofractionated range, can modulate tumor cells making them better targets for immune cell reactivity. Herein, we describe the range of phenotypic changes induced in tumor cells by radiation, and explore the diverse mechanisms of immunogenic modulation reported at these doses. We also review the impact of these doses on the immune cell function of cytotoxic cells in vivo and in vitro.

  13. Stereotactic radiation therapy and selective internal radiation therapy for hepatocellular carcinoma; Radiotherapie stereotaxique et radiotherapie interne selective du carcinome hepatocellulaire

    Energy Technology Data Exchange (ETDEWEB)

    Bujold, A.; Dawson, L.A. [Radiation Medicine Program, Princess Margaret Hospital, 610, University Avenue, Toronto M5G 2C1 (Canada)

    2011-02-15

    Recent technological advances allow precise and safe radiation delivery in hepatocellular carcinoma. Stereotactic body radiotherapy is a conformal external beam radiation technique that uses a small number of relatively large fractions to deliver potent doses of radiation therapy to extracranial sites. It requires stringent breathing motion control and image guidance. Selective internal radiotherapy or radio-embolization refers to the injection of radioisotopes, usually delivered to liver tumors via the hepatic artery. Clinical results for both treatments show that excellent local control is possible with acceptable toxicity. Most appropriate patient populations and when which type of radiation therapy should be best employed in the vast therapeutic armamentarium of hepatocellular carcinoma are still to be clarified. (authors)

  14. Postoperative radiation therapy for malignant glioma. Results of conventional radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Teshima, T.; Inoue, T.; Chatani, M.; Hata, K.; Taki, T.; Nii, Y.; Nakagawa, H.

    1987-02-01

    From December 1977 through September 1984, a total of 39 cases of malignant glioma were treated with radiation therapy (RT) postoperatively. Twenty-nine cases were classified into glioblastoma (GM) and 10 astrocytoma (AS) (low grade : 6 and anaplastic : 4) histologically. One third of cases received 50 Gy/25 FRX/5 WKS of whole brain RT. Another two thirds of cases underwent 60 Gy/30 FRX/6 WKS of whole brain or 50 Gy/25 FRX/5 WKS of whole brain + additional 20 Gy/10 FRX/2 WKS of localized field RT. Chemotherapy (BLM, MeCCNU and ACNU) was given for 34 cases. Survivals at 3 years for GM and AS were 12 % and 68 %, respectively. Prognostic factors for GM were age, neurologic function (RTOG), AJC-staging T-factor, pre-RT LDH level and volume of residual tumor. Corresponding factors for AS were histological subclassification and neurologic function (RTOG). However, RT dose and field did not impact on survival significantly. Acute adverse effects of RT were otitis media or externa (70 %) and conjunctivitis (8 %). Retinal bleeding was noted in three long-term survivors at 2 years after RT.

  15. Phenytoin Induced Erythema Multiforme after Cranial Radiation Therapy.

    Science.gov (United States)

    Kazanci, Atilla; Tekkök, İsmail Hakkı

    2015-08-01

    The prophylactic use of phenytoin during and after brain surgery and cranial irradiation is a common measure in brain tumor therapy. Phenytoin has been associated with variety of adverse skin reactions including urticaria, erythroderma, erythema multiforme (EM), Stevens-Johnson syndrome, and toxic epidermal necrolysis. EM associated with phenytoin and cranial radiation therapy (EMPACT) is a rare specific entity among patients with brain tumors receiving radiation therapy while on prophylactic anti-convulsive therapy. Herein we report a 41-year-old female patient with left temporal glial tumor who underwent surgery and then received whole brain radiation therapy and chemotherapy. After 24 days of continous prophylactic phenytoin therapy the patient developed minor skin reactions and 2 days later the patient returned with generalized erythamatous and itchy maculopapuler rash involving neck, chest, face, trunk, extremities. There was significant periorbital and perioral edema. Painful mucosal lesions consisting of oral and platal erosions also occurred and prevented oral intake significantly. Phenytoin was discontinued gradually. Systemic admistration of corticosteroids combined with topical usage of steroids for oral lesions resulted in complete resolution of eruptions in 3 weeks. All cutaneous lesions in patients with phenytoin usage with the radiotherapy must be evoluated with suspicion for EM.

  16. Long Term Results of Radiation Therapy in Early Glottic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hee; Byun, Sang Jun [Dongsan Medical Center, Daegu (Korea, Republic of)

    2009-03-15

    This study was designed to evaluate long-term results in terms of failure, survival and voice preservation after radiation therapy for early glottic cancer. From February 1988 to December 2003, 70 patients with early glottic cancer were treated with radiation therapy at Keimyung University Dongsan Medical Center. Patient age distribution was from 39 to 79 years, with a median age of 62 years. All patients had squamous cell carcinoma. According to the TNM stage, 58 patients had stage I disease, 12 patients had stage II disease; 67 patients were male. The laryngeal area was irradiated with the use of bilateral opposing fields with/without a wedge filter with 6 MV photons at a total dose of 54{approx}70.2 Gy in 1.8{approx}2.2 Gy fractions over 6{approx}8 weeks. We delivered a median radiation dose of 60 Gy for stage I patients and a median radiation dose of 66 Gy for stage II patients. Salvage surgery was performed in patients with local recurrence. The voice preservation rate was analyzed after all treatments including salvage surgery. Follow-up periods were from 13 to 180 months, with a median follow-up period of 77.5 months. The survival rate was analyzed by the use of the Kaplan Meier method and log rank test. A comparison of two groups was performed with the use of the chi-squared test. The local control rate was 98.5% (69/70). The five-year-overall survival rate was 93.9%. The five-year disease free survival rate (5YDFS) was 84.1% and the 5YDFS after radiation and salvage surgery was 92.8%. According to stage, the 5YDFS was 93.1% and 91.7% for stage I and stage II respectively. Thirteen patients (18.5%) had local failure with 24 months of median time to local failure and nine patients received salvage surgery; however, four patients were lost to follow-up after a diagnosis of recurrence. Only two patients died due to a distant metastasis at 33 months and 71 months after radiation therapy, respectively. Nine patients died due to other diseases with a median time

  17. SU-E-T-211: Peer Review System for Ensuring Quality of Radiation Therapy Treatments.

    Science.gov (United States)

    Kapoor, R; Kapur, P; Kumar, S A; Alex, D; Ranka, S; Palta, J

    2012-06-01

    To demonstrate a Web-based electronic peer review system that has the potential to improve quality of care for radiation therapy patients. The system provides tools that allow radiation oncologists to seek peer review of target and critical structure delineation, treatment plans, and share clinical data with peers to optimize radiation therapy treatments. Peer review of radiation therapy treatment planning data prior to its initiation improves the quality of radiation therapy and clinical outcomes. Web-based access to radiation therapy treatment planning data and medical records mitigate existing geographical and temporal constraints. With internet access, the healthcare provider can access the data from any location and review it in an interactive and collaborative manner. Interoperability standard like DICOM-RT and IHE-RO compliant RT Systems have facilitated the design and implementation of PRS with Silverlight Web technology, .net Framework and SQL Server. Local DICOM-RT archive and cloud based services are deployed to facilitate remote peer reviews. To validate the PRS system, we tested the system for 100 patients with Philips Pinnacle v 9.0 and Varian Eclipse v 8.9 treatment planning system (TPS). We transmitted the DICOM RT data from the TPS to the cloud based services via the PRS local DICOM RT Archive. Various CT simulation based parameters such as orientation of CT, properties of RT structures etc. were compared between the TPS and PRS system. Data integrity of other parameters such as patient demographics (patient name, ID, attending physician etc.) and dose volume related parameters were also evaluated. Such rigorous testing allowed us to optimize the functionalities and clinical implementation of the PRS. We believe that the PRS will improve the quality and safety of a broad spectrum of radiation therapy patients treated in underserved areas while discouraging the overutilization of expensive radiation treatment modalities. This research and

  18. Individual skin care during radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, J.S. [Klinik fuer Strahlentherapie (Radioonkologie), Christian-Albrechts-Universitaet Kiel (Germany); Budach, W. [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Eberhard-Carls-Universitaet Tuebingen (Germany); Doerr, W. [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Medizinische Fakultaet Carl Gustav Carus, Dresden (Germany)

    1998-11-01

    Background: In many clinical settings, the irradiated patient feels additional discomfort by the inhibition of washing the treatment portals and interruption of his adapted skin care habits. Material and methods: An analysis of the scientific recommendations as well as an analysis of the skin dose to the irradiated portals has been performed. An individual scheme for skin care under radiation has been developed. Results: A substantial decrease of the skin dose is achieved in many modern radiation techniques. The consequent reduction of severe skin reactions allowed the use of water and mild soaps as has been approved within many radiotherapy departments. This has lead to an individualized concept for skin care under radiation treatment including the allowance of gentle washing. The skin marks may be saved by using highly tolerable adhesive plasters or small tattoo points, if they are not superfluous by using masks or single referee points instead of marks for the field borders. Conclusions: The individualized concept for skin care during radiation may offer improved life quality to the patient and may decrease the acute reactions of the skin at least in some cases. (orig.) [Deutsch] Hintergrund: In vielen klinischen Situationen erfaehrt der bestrahlte Patient zusaetzliche Belastungen durch das frueher ausgesprochene Waschverbot der Bestrahlungsfelder wie auch durch die Unterbrechung seiner langjaehrigen Hygienegewohnheiten. Material und Methoden: Es wurde eine Analyse der wissenschaftlichen Empfehlungen wie auch der heutzutage bei modernen Bestrahlungstechniken auftretenden Hautdosis durchgefuehrt. Ein individuelles Schema zur Pflege der bestrahlten Haut wurde entwickelt. Ergebnisse: Durch eine Verringerung der Hautdosis und damit der Inzidenz schwerer Hautreaktionen bei modernen Bestrahlungstechniken wird mittlerweile in vielen Abteilungen das `Waschverbot` fuer bestrahlte Haut gelockert. Dies hat zu einem individualisierten Hautpflegekonzept unter der Bestrahlung

  19. Salvage radiation therapy following radical prostatectomy

    DEFF Research Database (Denmark)

    Ervandian, Maria; Høyer, Morten; Petersen, Stine Elleberg

    2016-01-01

    .0%. Nearly half of the patients (44%) received androgen deprivation therapy (ADT) in combination with SRT. Positive surgical tumour margins (p = 0.025) and ADT (p = 0.001) were the only markers independently correlated with b-PFS. In patients who received SRT without ADT, both a pre-SRT PSA level ≤0.5 ng...

  20. Maxillary sinus carcinoma: result of radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, H.; Horiuchi, J.; Suzuki, S.; Shioda, S.; Enomoto, S.

    1984-07-01

    This hundred and sixteen patients with carcinoma of the maxillary sinus received primary therapy consisting of external beam irradiation alone or in combination with surgery and/or chemotherapy at the Department of Radiology, Tokyo Medical and Dental University Hospital, between 1953 and 1982. In our institution, methods of treating cancer of the maxillary sinus have been changed from time to time and showed different control rates and clinical courses. An actuarial 10-year survival rate of 21% has been obtained by the megavoltage irradiation alone as well as 34% actuarial 10-year survival rate by megavoltage irradiation with surgery. After the introduction of conservative surgery followed by conventional trimodal combination therapy, the local control rate has been improved. The amount of functional, cosmetic, and brain damages have been remarkably decreased by this mode of therapy. The actuarial five year survival rate was 67%. In addition, along with the improvement of the local control rate, the control of nodal and distant organ metastases have been emerging as one of the important contributions to the prognosis of this disease.

  1. Complications after radiation therapy for cervical carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, M. (Iwate Medical Coll., Morioka (Japan). School of Medicine)

    1981-04-01

    From 1966 to 1973, 215 patients with cervical cancer were treated at the Department of Obstetrics and Gynecology, School of Medicine, Iwate Medical University. The patients were divided into two groups. In the first group, 123 patients were treated by external radiation with Tele-/sup 60/Co plus radium insertions (1966-1970). In the second group, 83 patients were treated with linear accelerator plus cesium insertions (1970-1973). The results on both of 5-year survival rate and appearance of radiation injuries were compared with in the two groups. There was no significant difference in the cure rate between those groups. The incidence of pigmentation, edema and diarrhea (early complications) was higher and the diarrhea continued significantly longer in the second group. The incidence of rectal ulcer and rectostenosis (later complications) was significantly higher than former group. A study was made to learn the reason for the significantly higher occurrence of rectal ulcer and rectostenosis. As a result, it was determined that later complication was more emphasized especially by dose rate of intracavitary irradiation. In addition, it is thought that the dose rate, the dose volume and natural history such as the patients' age are also related to the severity of the complications.

  2. BRCA1 Mutation: A Predictive Marker for Radiation Therapy?

    Energy Technology Data Exchange (ETDEWEB)

    Kan, Charlene; Zhang, Junran, E-mail: Junran.zhang@case.edu

    2015-10-01

    DNA repair, in particular, DNA double-strand break (DSB) repair, is essential for the survival of both normal and cancer cells. An elaborate repair mechanism has been developed in cells to efficiently repair the damaged DNA. The pathways predominately involved in DSB repair are homologous recombination and classic nonhomologous end-joining, although the alternative NHEJ pathway, a third DSB repair pathway, could also be important in certain contexts. The protein of BRCA1 encoded by the tumor suppressor gene BRCA1 regulates all DSB repair pathways. Given that DSBs represent the most biologically significant lesions induced by ionizing radiation and that impaired DSB repair leads to radiation sensitivity, it has been expected that cancer patients with BRCA1 mutations should benefit from radiation therapy. However, the clinical data have been conflicting and inconclusive. We provide an overview about the current status of the data regarding BRCA1 deficiency and radiation therapy sensitivity in both experimental models and clinical investigations. In addition, we discuss a strategy to potentiate the effects of radiation therapy by poly(ADP-ribose) polymerase inhibitors, the pharmacologic drugs being investigated as monotherapy for the treatment of patients with BRCA1/2 mutations.

  3. Waiting Lists for Radiation Therapy: A Case Study

    Directory of Open Access Journals (Sweden)

    Singer Peter A

    2001-04-01

    Full Text Available Abstract Background Why waiting lists arise and how to address them remains unclear, and an improved understanding of these waiting list "dynamics" could lead to better management. The purpose of this study is to understand how the current shortage in radiation therapy in Ontario developed; the implications of prolonged waits; who is held accountable for managing such delays; and short, intermediate, and long-term solutions. Methods A case study of the radiation therapy shortage in 1998-99 at Princess Margaret Hospital, Toronto, Ontario, Canada. Relevant documents were collected; semi-structured, face-to-face interviews with ten administrators, health care workers, and patients were conducted, audio-taped and transcribed; and relevant meetings were observed. Results The radiation therapy shortage arose from a complex interplay of factors including: rising cancer incidence rates; broadening indications for radiation therapy; human resources management issues; government funding decisions; and responsiveness to previous planning recommendations. Implications of delays include poorer cancer control rates; patient suffering; and strained doctor-patient relationships. An incompatible relationship exists between moral responsibility, borne by government, and legal liability, borne by physicians. Short-term solutions include re-referral to centers with available resources; long-term solutions include training and recruiting health care workers, improving workload standards, increasing compensation, and making changes to the funding formula. Conclusion Human resource planning plays a critical role in the causes and solutions of waiting lists. Waiting lists have harsh implications for patients. Accountability relationships require realignment.

  4. The role of radiation therapy in epithelial ovarian cancer | Dreyer ...

    African Journals Online (AJOL)

    The role of radiation therapy in epithelial ovarian cancer. G Dreyer. Abstract. No Abstract. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

  5. A maximum feasible subset algorithm with application to radiation therapy

    DEFF Research Database (Denmark)

    Sadegh, Payman

    1999-01-01

    . The algorithm relies on an iterative constraint removal procedure where constraints are eliminated from a set proposed by solutions to minmax linear programs. The method is illustrated by a simulated example of a linear system with double sided bounds and a case from the area of radiation therapy....

  6. Baroreflex failure following radiation therapy for nasopharyngeal carcinoma

    NARCIS (Netherlands)

    Timmers, H. J.; Karemaker, J. M.; Lenders, J. W.; Wieling, W.

    1999-01-01

    The authors present a 51-year-old man with right-sided nasopharyngeal carcinoma who was treated for regional lymph node involvement by bilateral radiation therapy of the neck. Six years later he presented with episodic complaints of headache, flushing, and palpitations accompanied by elevations of

  7. Radiation therapy in the multimodal treatment approach of pituitary adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G. [Klinik am Eichert, Goeppingen (Germany). Dept. of Radiooncology and Radiation Therapy; Radiooncologic Univ. Clinic, Tuebingen (Germany); Kocher, M.; Mueller, R.P. [Koeln Univ. (Germany). Clinic of Radiation Therapy; Kortmann, R.D.; Paulsen, F.; Jeremic, B.; Bamberg, M. [Radiooncologic Univ. Clinic, Tuebingen (Germany)

    2002-04-01

    In this paper, literature will be reviewed to assess the role of modern radiotherapy and radiosurgery in the management of pituitary adenomas. Material and Methods: Nowadays, magnetic resonance imaging for the definition of the target volume and a real three-dimensional (3-D) treatment planning with field conformation and the possibility for non-coplanar irradiation has to be recommended. Most groups irradiate these benign tumors with single doses of 1.8-2.0 Gy up to a total dose of 45 Gy or 50.4 Gy in extensive parasellar adenomas. Adenomas are mostly small, well circumscribed lesions, and have, therefore, attracted the use of stereotactically guided high-precision irradiation techniques which allow extreme focussing and provide steep dose gradients with selective treatment of the target and optimal protection of the surrounding brain tissue. Results: Radiation therapy controls tumor growth in 80-98% of patients with non-secreting adenomas and 67-89% for endocrine active tumors. Reviewing the recent literature including endocrine active and non-secreting adenomas, irradiated postoperatively or in case of recurrence the 5-, 10- and 15-year local control rates amount 92%, 89% and 79%. In cases of microprolactinoma primary therapy consists of dopamine agonists. Irradiation should be preferred in patients with macroprolactinomas, when drug therapy and/or surgery failed or for patients medically unsuitable for surgery. Reduction and control of prolactin secretion can be achieved in 44-70% of patients. After radiotherapy in acromegaly patients somatomedin-C and growth hormone concentrations decrease to normal levels in 70-90%, with a decrease rate of 10-30% per year. Hypercortisolism is controlled in 50-83% of adults and 80% of children with Cushing's disease, generally in less than 9 months. Hypopituitarism is the most common side effect of pituitary irradiation with an incidence of 13-56%. Long-term overall risk for brain necrosis in a total of 1,388 analyzed

  8. The quest for optimal antimicrobial therapy

    NARCIS (Netherlands)

    Mol, Petrus Gerardus Maria

    2005-01-01

    Since the discovery of sulphonam ides and penicillin in the 1930's, and their widespread use in clinical practice during World War II a plethora of new antimicrobial agents have entered the market. Initial optim ism has faded that these new drugs would eliminate infectious diseases as killer

  9. Optimal Furosemide Therapy in Critically Ill infants

    NARCIS (Netherlands)

    M.M.J. van der Vorst

    2007-01-01

    textabstractFurosemide as continuous infusion is used in infants after cardiopulmonary bypass (CPB) surgery and during extracorporeal membrane oxygenation (ECMO). The currently used regimens which start with low dose (0.05 - 0.1 mg/kg.hr) may not be optimal in this group of patients with

  10. Gastrointestinal Toxicities With Combined Antiangiogenic and Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pollom, Erqi L.; Deng, Lei [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Pai, Reetesh K. [Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Brown, J. Martin; Giaccia, Amato; Loo, Billy W.; Shultz, David B.; Le, Quynh Thu; Koong, Albert C. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Chang, Daniel T., E-mail: dtchang@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States)

    2015-07-01

    Combining the latest targeted biologic agents with the most advanced radiation technologies has been an exciting development in the treatment of cancer patients. Stereotactic body radiation therapy (SBRT) is an ablative radiation approach that has become established for the treatment of a variety of malignancies, and it has been increasingly used in combination with biologic agents, including those targeting angiogenesis-specific pathways. Multiple reports have emerged describing unanticipated toxicities arising from the combination of SBRT and angiogenesis-targeting agents, particularly of late luminal gastrointestinal toxicities. In this review, we summarize the literature describing these toxicities, explore the biological mechanism of action of toxicity with the combined use of antiangiogenic therapies, and discuss areas of future research, so that this combination of treatment modalities can continue to be used in broader clinical contexts.

  11. Intraoperative radiation therapy for noncuratively resected pancreatic carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Atsutake; Tsuruta, Kohji; Tabata, Ikuo; Isawa, Tomoaki; Kamisawa, Terumi; Tanaka, Yoshiaki (Tokyo Metropolitan Komagome Hospital (Japan))

    1992-08-01

    The effect of intraoperative radiation therapy (IORT) was studied in 20 patients with noncuratively resected pancreatic carcinoma. Seventeen out of the 20 patients also received external beam radiation therapy (EBRT) by conformation radiation. The IORT targets were the retroperitoneal tissues, such as lymph vessels, nerve plexuses around the SMA and the wall of the SMV where macroscopic or microscopic residual might remain. The one-, and 2 year survival rates were 52.6%, and 10.5%, respectively, with a median survival of 12.1 months, in 19 patients excluding one operative death. These survival rates were not significantly different from those in 30 patients with unresectable tumors treated by IORT in combination with EBRT, though their tumor conditions were more advanced. From these, the treatment with IORT plus EBRT should be useful for patients with advanced disease, avoiding aggressive tumor resection, if tumor resection becomes noncurative. At present, we approach to evaluate possible effects of IORT for curative tumor resection. (author).

  12. Radiation therapy-associated invasive bladder tumors

    Energy Technology Data Exchange (ETDEWEB)

    Sella, A.; Dexeus, F.H.; Chong, C.; Ro, J.Y.; Logothetis, C.J.

    1989-03-01

    Radiotherapy-associated bladder carcinoma was found in 3.7 percent of 244 cases of advanced urothelial carcinoma. Average age at diagnosis of the bladder tumor was 63.1 years, with a mean of 20.5 years between radiation treatment and diagnosis. All 9 patients presented with gross hematuria. Eight patients had transitional cell carcinoma, 7/8 (87.5%) also had vascular or lymphatic invasion, and 1 was adenocarcinoma. Mean survival was 15.4 months (range 1-40 mos.), with a 55.5 percent one-year disease-free survival after diagnosis. Four patients died of bladder tumor, 4 were alive with no evidence of disease, and 1 was alive with metastasis.

  13. Optimization approaches to volumetric modulated arc therapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu; Bortfeld, Thomas; Craft, David [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Alber, Markus [Department of Medical Physics and Department of Radiation Oncology, Aarhus University Hospital, Aarhus C DK-8000 (Denmark); Bangert, Mark [Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg D-69120 (Germany); Bokrantz, Rasmus [RaySearch Laboratories, Stockholm SE-111 34 (Sweden); Chen, Danny [Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Li, Ruijiang; Xing, Lei [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Men, Chunhua [Department of Research, Elekta, Maryland Heights, Missouri 63043 (United States); Nill, Simeon [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG (United Kingdom); Papp, Dávid [Department of Mathematics, North Carolina State University, Raleigh, North Carolina 27695 (United States); Romeijn, Edwin [H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Salari, Ehsan [Department of Industrial and Manufacturing Engineering, Wichita State University, Wichita, Kansas 67260 (United States)

    2015-03-15

    Volumetric modulated arc therapy (VMAT) has found widespread clinical application in recent years. A large number of treatment planning studies have evaluated the potential for VMAT for different disease sites based on the currently available commercial implementations of VMAT planning. In contrast, literature on the underlying mathematical optimization methods used in treatment planning is scarce. VMAT planning represents a challenging large scale optimization problem. In contrast to fluence map optimization in intensity-modulated radiotherapy planning for static beams, VMAT planning represents a nonconvex optimization problem. In this paper, the authors review the state-of-the-art in VMAT planning from an algorithmic perspective. Different approaches to VMAT optimization, including arc sequencing methods, extensions of direct aperture optimization, and direct optimization of leaf trajectories are reviewed. Their advantages and limitations are outlined and recommendations for improvements are discussed.

  14. Oxygenation of spontaneous canine tumors during fractionated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Achermann, R.E.; Ohlerth, S.M.; Bley, C.R.; Inteeworn, N.; Schaerz, M.; Wergin, M.C.; Kaser-Hotz, B. [Section of Diagnostic Imaging and Radiation Oncology, Veterinary School, Univ. of Zurich (Switzerland); Gassmann, M. [Inst. for Veterinary Physiology, Univ. of Zurich (Switzerland); Roos, M. [Inst. for Social and Preventive Medicine, Univ. of Zurich (Switzerland)

    2004-05-01

    Background and purpose: tumor oxygenation predicts treatment outcome, and reoxygenation is considered important in the efficacy of fractionated radiation therapy. Therefore, the purpose of this study was to document the changes of the oxygenation status in spontaneous canine tumors during fractionated radiation therapy using polarographic needle electrodes. Material and methods: tumor oxygen partial pressure (pO{sub 2}) measurements were performed with the eppendorf-pO{sub 2}-Histograph. The measurements were done under general anesthesia, and probe tracks were guided with ultrasound. pO{sub 2} was measured before radiation therapy in all dogs. In patients treated with curative intent, measurements were done sequentially up to eight times (total dose: 45-59.5 Gy). Oxygenation status of the palliative patient group was examined before each fraction of radiation therapy up to five times (total dose: 24-30 Gy). Results: 15/26 tumors had a pretreatment median pO{sub 2} {<=} 10 mmHg. The pO{sub 2} values appeared to be quite variable in individual tumors during fractionated radiation therapy. The pO{sub 2} of initially hypoxic tumors (pretreatment median pO{sub 2} {<=} 10 mmHg) remained unchanged during fractionated radiotherapy, whereas in initially normoxic tumors the pO{sub 2} decreased. Conclusion: hypoxia is common in spontaneous canine tumors, as 57.7% of the recorded values were {>=} 10 mmHg. The data of this study showed that initially hypoxic tumors remained hypoxic, whereas normoxic tumors became more hypoxic. (orig.)

  15. The Results of Postoperative Radiation Therapy in the Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Ja [Ewha Womans University College of Medicine, Seoul (Korea, Republic of)

    1994-02-15

    Purpose: Despite apparently complete resection of cancer of the rectum, local recurrence rate was high. Radiation therapy has been used either alone or in combination with chemotherapy as an adjunct to surgery to reduce the risk of recurrence. This study was designed to evaluate the prognostic factors, survival rate and local recurrence rate of the rectal cancer who had received postoperative radiation therapy by retrospective analysis. Method: From 1982 to 1990, 63 patients with cancer of the rectum surgically staged as B2 or C disease received postoperative adjuvant radiation therapy after curative resection of tumor for cure. Postoperative radiation therapy was given to the whole pelvis (mean dose: 5040 cGy in 5-6weeks) and perineum was included in irradiated field in case of abdominoperineal resection. Results: Three-year actuarial survival rate was 73.2% overall, 87.7% in stage B2+3 and 62.9% in stage C2+3. Three-year disease-free survival rate was 69.5% overall, 87.7% in stage B2+3 and 56.8% in stage C2+3. Three-year disease-free survival rate in anterior resection was 77.8% and 44.4% in abdominoperineal resection. The local recurrence rate was 15.9% and distant failure rate was 20.6%. Severe late complication was small bowel obstruction in 6 patients and surgery was required in 4 patients (6.3%). The prognostic factors were stage (p=0.0221) and method of surgery(p=0.0414) (anterior resection vs abdominoperineal resection). Conclusion: This study provides evidence supporting the use of postoperative radiation therapy for reducing the local recurrence rate in patients who have had curative resection of rectal cancer with involvement of perirectal fat or regional nodes or both (stage B2 and C)

  16. Modern Radiation Therapy and Cardiac Outcomes in Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Boero, Isabel J.; Paravati, Anthony J.; Triplett, Daniel P.; Hwang, Lindsay; Matsuno, Rayna K.; Gillespie, Erin F.; Yashar, Catheryn M.; Moiseenko, Vitali; Einck, John P.; Mell, Loren K. [Department of Radiation Medicine and Applied Sciences, Moores Cancer Center, University of California, San Diego, La Jolla, California (United States); Parikh, Sahil A. [University Hospitals Case Medical Center, Harrington Heart and Vascular Institute, and Case Western Reserve University School of Medicine, Cleveland, Ohio (United States); Murphy, James D., E-mail: j2murphy@ucsd.edu [Department of Radiation Medicine and Applied Sciences, Moores Cancer Center, University of California, San Diego, La Jolla, California (United States)

    2016-03-15

    Purpose: Adjuvant radiation therapy, which has proven benefit against breast cancer, has historically been associated with an increased incidence of ischemic heart disease. Modern techniques have reduced this risk, but a detailed evaluation has not recently been conducted. The present study evaluated the effect of current radiation practices on ischemia-related cardiac events and procedures in a population-based study of older women with nonmetastatic breast cancer. Methods and Materials: A total of 29,102 patients diagnosed from 2000 to 2009 were identified from the Surveillance, Epidemiology, and End Results–Medicare database. Medicare claims were used to identify the radiation therapy and cardiac outcomes. Competing risk models were used to assess the effect of radiation on these outcomes. Results: Patients with left-sided breast cancer had a small increase in their risk of percutaneous coronary intervention (PCI) after radiation therapy—the 10-year cumulative incidence for these patients was 5.5% (95% confidence interval [CI] 4.9%-6.2%) and 4.5% (95% CI 4.0%-5.0%) for right-sided patients. This risk was limited to women with previous cardiac disease. For patients who underwent PCI, those with left-sided breast cancer had a significantly increased risk of cardiac mortality with a subdistribution hazard ratio of 2.02 (95% CI 1.23-3.34). No other outcome, including cardiac mortality for the entire cohort, showed a significant relationship with tumor laterality. Conclusions: For women with a history of cardiac disease, those with left-sided breast cancer who underwent radiation therapy had increased rates of PCI and a survival decrement if treated with PCI. The results of the present study could help cardiologists and radiation oncologists better stratify patients who need more aggressive cardioprotective techniques.

  17. Occurrence of BOOP outside radiation field after tangential radiation therapy for breast carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Hamanishi, Tohru; Gohma, Iwao; Oida, Kazukiyo [Tenri Hospital, Nara (Japan)] (and others)

    2000-07-01

    We report three cases of bronchiolitis obliterans organizing pneumonia (BOOP) that occurred outside the radiation field after radiation therapy using tangential fields for breast carcinoma. All patients complained of a cough between 14 and 20 weeks after completion of radiation therapy. Fever also developed in two of the three. Chest radiography and computed tomography demonstrated peripheral alveolar opacities outside the radiation field on the same side as the radiation therapy. Laboratory data showed an increased level of C-reactive protein and an increased erythrocyte sedimentation rate. Bronchoalveolar lavage showed an elevated total cell count with a very high percentage of lymphocytes. Transbronchial lung biopsy revealed a histologic pattern consistent with BOOP. Treatment with corticosteroids resulted in rapid clinical improvement and complete resolution of the radiographic abnormalities. This pulmonary disorder appears to be induced by radiation, especially when a tangential field is employed for breast carcinoma, though the etiology has not been fully investigated. It is important to be aware of this type of pulmonary complication in patients given radiotherapy for breast carcinoma. (author)

  18. Hyperbaric oxygen therapy for delayed radiation injuries in gynecological cancers.

    Science.gov (United States)

    Fink, D; Chetty, N; Lehm, J P; Marsden, D E; Hacker, N F

    2006-01-01

    Delayed radiation-induced injuries are difficult to treat. The treatment of delayed radiation injuries with hyperbaric oxygen therapy (HBOT) is reported in small case series and case reports. This study reports the experience of a single institution with HBOT in delayed radiation injuries in patients with gynecological cancers. At least 20 sessions of 100% oxygen inhalation at 2.4 Atmospheric Absolutes (ATA) for 90 min in a hyperbaric chamber were carried out. Of the 14 patients included in the study, 10 patients have healed or showed improvement of more than 50%, resulting in a success rate of 71%. Mean follow-up was 31.6 months (range 6-70 months). The adverse events were acceptable. HBOT should be considered for patients with delayed radiation injuries, not responding to other treatments.

  19. What to Know about Brachytherapy (A Type of Internal Radiation Therapy)

    Science.gov (United States)

    N ational C ancer I nstitute Understanding Radiation Therapy What To Know About Brachytherapy (A Type of Internal Radiation Therapy) “I asked questions. My doctor took the time to help my family ...

  20. Scope of nanotechnology-based radiation therapy and thermotherapy methods in cancer treatment.

    Science.gov (United States)

    Bakht, Mohamadreza K; Sadeghi, Mahdi; Pourbaghi-Masouleh, Milad; Tenreiro, Claudio

    2012-10-01

    The main aim of nanomedicine is to revolutionize the health care system and find effective approaches to fighting fatal diseases. Therapeutic beams, which are employed in radiation therapy, do not discriminate between normal and cancerous cells and must rely on targeting the radiation beams to specific cells. Interestingly, the application of nanoscale particles in radiation therapy has aimed to improve outcomes in radiation therapy by increasing toxicity in tumors and reducing it in normal tissues. This review focuses on approaches to nanotechnology-based cancer radiation therapy methods such as radionuclide therapy, photodynamic therapy, and neutron capture therapy. Moreover, we have investigated nanotechnology-based thermotherapy methods, including hyperthermia and thermoablation, as non-ionizing modalities of treatment using thermal radiation. The results strongly demonstrate that nanotechnology-based cancer radiation therapy and thermotherapy methods hold substantial potential to improve the efficacy of anticancer radiation and thermotherapy modalities.

  1. Anaemia and radiation therapy; Anemie et radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Denis, F. [Clinique d' Oncologie et de Radiotherapie, INSERM U619, 37 - Tours (France); Lartigau, E. [Centre de Lutte Contre le Cancer Oscar-Lambret, Dept. de Radiotherapie, 59 - Lille (France)

    2004-11-01

    Anaemia is frequent in cancer and may increase tumour hypoxia that stimulates angiogenesis. However, erythropoietin is a hypoxia-inducible stimulator of erythropoiesis which seems to improve quality of life in cancer patients. Two recent phase III randomized studies showed negative results using erythropoietin in head and neck cancer patients and in metastatic breast cancer patients with impaired specific survival. In vitro and in vivo experiments have provided erythropoietin-receptor expression in endothelial cancer cells including malignant tumours of the breast, prostate, cervix, lung, head and neck, ovary, melanoma, stomach, gut, kidney etc. Biologic effect of erythropoietin and its receptor linkage induces proliferation of human breast cancer and angiogenesis and may limit anti-tumour effect of cancer treatment, in part, by tumour vascularization improvement. In addition, the use of exogenous erythropoietin could be able to favour tumour progression by improving tumour oxygenation and nutriment supply. If erythropoietin receptor were functional in human cancer. the assessment of erythropoietin receptor expression on tumour cell may help to select patients benefiting from exogenous erythropoietin. However. the relationship between erythropoietin receptor expression, tumour growth and exogenous erythropoietin. requires more studies. The results of recent clinical trials suggest that using erythropoietin should be avoided in non-anemic patients and discussed in patients receiving curative therapy. (authors)

  2. Radiobiological risk estimates of adverse events and secondary cancer for proton and photon radiation therapy of pediatric medulloblastoma

    DEFF Research Database (Denmark)

    Brodin, N Patrik; Munck af Rosenschöld, Per Martin; Aznar, Marianne C

    2011-01-01

    The aim of this model study was to estimate and compare the risk of radiation-induced adverse late effects in pediatric patients with medulloblastoma (MB) treated with either three-dimensional conformal radiotherapy (3D CRT), inversely-optimized arc therapy (RapidArc(®) (RA)) or spot...

  3. Three dimensional conformal radiation therapy may improve the therapeutic ratio of radiation therapy after pneumonectomy for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Trouette, R.; Causse, N.; Elkhadri, M.; Caudry, M.; Maire, J.P.; Houlard, J.P.; Racaldini, L.; Demeaux, H.

    1995-12-01

    Three dimensional conformal radiation therapy would allow to decrease the normal tissue dose while maintaining the same target dose as standard treatment. To evaluate the feasibility of normal tissue dose reduction for ten patients with pneumonectomy for lung cancer, we determined the dose distribution to the normal tissue with 3-dimensional conformal radiation therapy (3-DCRT) and conventional treatment planning (CTP). Dose-volume histograms for target and normal tissue (lung, heart) were used for comparison of the different treatment planning. The mean percentages of lung and heart volumes which received 40 Gy with 3-DCRT were respectively 63% and 37% of the mean percentage of lung and volumes which received the same dose with CTP. These preliminary results suggest that conformal therapy may improve the therapeutic ratio by reducing risk to normal tissue.

  4. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Science.gov (United States)

    2010-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., and Radiation Therapy Technologists The following section describes basic elements to be incorporated... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2. Licenses...

  5. Neutrophils, a candidate biomarker and target for radiation therapy?

    Science.gov (United States)

    Schernberg, Antoine; Blanchard, Pierre; Chargari, Cyrus; Deutsch, Eric

    2017-11-01

    Neutrophils are the most abundant blood-circulating white blood cells, continuously generated in the bone marrow. Growing evidence suggests they regulate the innate and adaptive immune system during tumor evolution. This review will first summarize the recent findings on neutrophils as a key player in cancer evolution, then as a potential biomarker, and finally as therapeutic targets, with respective focuses on the interplay with radiation therapy. A complex interplay: Neutrophils have been associated with tumor progression through multiple pathways. Ionizing radiation has cytotoxic effects on cancer cells, but the sensitivity to radiation therapy in vivo differ from isolated cancer cells in vitro, partially due to the tumor microenvironment. Different microenvironmental states, whether baseline or induced, can modulate or even attenuate the effects of radiation, with consequences for therapeutic efficacy. Inflammatory biomarkers: Inflammation-based scores have been widely studied as prognostic biomarkers in cancer patients. We have performed a large retrospective cohort of patients undergoing radiation therapy (1233 patients), with robust relationship between baseline blood neutrophil count and 3-year's patient's overall survival in patients with different cancer histologies. (Pearson's correlation test: p = .001, r = -.93). Therapeutic approaches: Neutrophil-targeting agents are being developed for the treatment of inflammatory and autoimmune diseases. Neutrophils either can exert antitumoral (N1 phenotype) or protumoral (N2 phenotype) activity, depending on the Tumor Micro Environment. Tumor associated N2 neutrophils are characterized by high expression of CXCR4, VEGF, and gelatinase B/MMP9. TGF-β within the tumor microenvironment induces a population of TAN with a protumor N2 phenotype. TGF-β blockade slows tumor growth through activation of CD8 + T cells, macrophages, and tumor associated neutrophils with an antitumor N1 phenotype. This supports

  6. The effect of radiation therapy on hemophilic arthropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jin Oh; Hong, Seong Eon; Kim, Sang Gi; Shin, Dong Oh [School of Medicine, KyungHee University, Seoul (Korea, Republic of)

    2005-06-15

    Repetitive bleeding into the joint space is the cause of debilitative hemophilic arthropathy. To interrupt this process, we treated the hemophilic patients suffering from repetitive joint bleeding with radiation therapy. From 1997 to 2001, a total of 41 joints from 37 hemophilic arthropathy patients were treated with radiation therapy at KyungHee University Hospital. The treated joints were 35 ankles, 3 knees and 3 elbows, respectively. The age of the patients ranged from 4 to 27 years (median age: 11 years). The radiation dose ranged from 900 cGy to 2360 cGy (median dose: 900 cGy). The fraction size was 150 cGy, 180 cGy or 200 cGy. The number of bleeding in one year before and after radiotherapy was compared. There was a tendency of frequent bleeding for the patients younger than 11 ({rho} 0.051) but there was also a tendency for more improvement in this group ({rho} 0.057). The number of joint bleedings was related with joint pain ({rho} 0.012) and joint swelling ({rho} = 0.033) but not with the Arbold-Hilgartner stage ({rho} 0.739),cartilage destruction ({rho} = 0.718) and synovial hypertrophy ({rho} = 0.079). The number of bleeding was reduced in thirty-three cases, and eight cases showed no improvement after radiation therapy. The average number of bleeding in a month was 2.52 before radiotherapy, but this was reduced to 1.4 after radiotherapy ({rho} = 0.017). Radiation therapy was effective for the hemophilia patients with repetitive joint bleeding to decrease the bleeding frequency and to prevent hemophilic arthropathy.

  7. Radiation therapy in the treatment of metastatic renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Onufrey, V.; Mohiuddin, M.

    1985-11-01

    Adenocarcinoma of the kidney is an unusual tumor, both in its biological behavior and in its response to radiation treatment. Historically, these tumors have been considered to be radioresistant, and the role of radiation therapy remains questionable in the primary management of this disease. However, radiation treatment is routinely used in the palliation of metastatic lesions for relief of symptoms. Therefore, we have undertaken a review of our experience in the treatment of this disease to determine the effectiveness of radiation in its palliation. From 1956 to 1981, 125 patients with metastatic lesions from hypernephroma have been treated in the Department of Radiation Therapy at Thomas Jefferson University Hospital. Most patients were referred for relief of bone pain (86), brain metastasis (12), spinal cord compression (9), and soft tissue masses (18). Total doses varied from 2000 rad to a maximum of 6000 rad. Response to treatment was evaluated on the basis of relief of symptoms, either complete, partial or no change. Our results indicate a significantly higher response rate of 65% for total doses equal to or greater than a TDF of 70, as compared to 25% for doses lower than a TDF of 70. No difference in response was observed either for bone or soft tissue metastasis or visceral disease. This leads us to believe that metastatic lesions from adenocarcinomas of the kidney should be treated to higher doses to obtain maximum response rates. Analysis of these results are presented in detail.

  8. Immunotherapy and radiation therapy for malignant pleural mesothelioma

    Science.gov (United States)

    Katz, Sharyn I.; Cengel, Keith A.; Simone, Charles B.

    2017-01-01

    Malignant pleural mesothelioma (MPM) is a particularly aggressive thoracic malignancy with limited survival following combination chemotherapy. As a result, there has been increased interested in immunotherapy for mesothelioma, both in the first-line and salvage settings. Early investigations of interleukin-2 (IL-2) and interferon alfa-2a/b have been limited by modest response rates and toxicity, whereas cytokine gene therapy is currently being investigated and shows early promise. The most prominent class of immunotherapies to be trialed with mesothelioma in the past half-decade has been immune checkpoint inhibitors (CPI). Early results are encouraging, particularly for agents targeting the PD-1/PD-L1 pathways. With the increasing recognition of the immune potential of mesothelioma, interest in the immunomodulatory properties of radiation therapy has emerged. The combination of immunotherapy and radiation therapy may allow for complimentary immunologic effects that can enhance antitumor response. This article reviews the existing literature on the efficacy of immunotherapy for MPM, describes the rationale for combining immunotherapy with radiation therapy, and discusses early literature on this treatment combination. PMID:28529903

  9. Gold Nanoparticles and Their Alternatives for Radiation Therapy Enhancement

    Directory of Open Access Journals (Sweden)

    Daniel R. Cooper

    2014-10-01

    Full Text Available Radiation therapy is one of the most commonly used treatments for cancer. The dose of delivered ionizing radiation can be amplified by the presence of high-Z materials via an enhancement of the photoelectric effect; the most widely studied material is gold (atomic number 79. However, a large amount is needed to obtain a significant dose enhancement, presenting a challenge for delivery. In order to make this technique of broader applicability, the gold must be targeted, or alternative formulations developed that do not rely solely on the photoelectric effect. One possible approach is to excite scintillating nanoparticles with ionizing radiation, and then exploit energy transfer between these particles and attached dyes in a manner analogous to photodynamic therapy. Doped rare-earth halides and semiconductor quantum dots have been investigated for this purpose. However, although the spectrum of emitted light after radiation excitation is usually similar to that seen with light excitation, the yield is not. Measurement of scintillation yields is challenging, and in many cases has been done only for bulk materials, with little understanding of how the principles translate to the nanoscale. Another alternative is to use local heating using gold or iron, followed by application of ionizing radiation. Hyperthermia pre-sensitizes the tumors, leading to an improved response. Another approach is to use chemotherapeutic drugs that can radiosensitize tumors. Drugs may be attached to high-Z nanoparticles or encapsulated. This article discusses each of these techniques, giving an overview of the current state of nanoparticle-assisted radiation therapy and future directions.

  10. Radiation therapy for metastatic lesions from breast cancer. Breast cancer metastasis to bone

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Shinya; Hoshi, Hiroaki [Gifu Univ. (Japan). School of Medicine

    2000-10-01

    -fraction irradiation, however, is not in commonly used in Japan, and it has been reported that there is no significant difference in pain palliation between single-fraction irradiation and multi-fraction irradiation. The effectiveness of prophylactic use of single-fraction irradiation to prevent fractures is unclear. Hemibody (or wide-field) radiation therapy is used to palliate pain from multiple bone metastases or as adjuvant therapy after local-field irradiation, but it has not been widely used in Japan because of adverse reactions. Further investigation is needed to determine the optimal method in terms of irradiation dose, timing of combination therapy, and reduction of adverse reactions. Systemic radionuclide treatment with 89SrCl is used for pain palliation and as adjuvant therapy after local-field irradiation. 89SrCl therapy is considered useful in improving the QOL of breast cancer patients with bone metastasis. Although phase III clinical trials of 89SrCl therapy have been completed in Japan, it will be several more years before clinical use of 89SrCl is approved. The mechanism of pain palliation by radiation therapy has not yet been clarified, however, it cannot be explained by the antitumor effect of irradiation alone. It is suspected that radiation therapy may suppress osteoclast function, the secretion of various cytokines causing pain stimuli, and the proliferation of tumor cells in bone. Clarification of the basic mechanism of pain palliation will be useful in determining the optimal irradiation schedule. Spinal cord compression occurs in about 5% of patients with malignant tumors, and it is particularly frequent in breast cancer, lung cancer, and prostate cancer. It usually requires surgery or radiation therapy. Neuropathic symptoms cannot be treated by radiation therapy alone. Accordingly, surgery is recommended for the purpose of diagnosis and treatment whenever spinal cord compression is suspected. Although steroid therapy is frequently combined with radiation

  11. Analysis of Radiation Treatment Planning by Dose Calculation and Optimization Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Sup; Yoon, In Ha; Lee, Woo Seok; Baek, Geum Mun [Dept. of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)

    2012-09-15

    Analyze the Effectiveness of Radiation Treatment Planning by dose calculation and optimization algorithm, apply consideration of actual treatment planning, and then suggest the best way to treatment planning protocol. The treatment planning system use Eclipse 10.0. (Varian, USA). PBC (Pencil Beam Convolution) and AAA (Anisotropic Analytical Algorithm) Apply to Dose calculation, DVO (Dose Volume Optimizer 10.0.28) used for optimized algorithm of Intensity Modulated Radiation Therapy (IMRT), PRO II (Progressive Resolution Optimizer V 8.9.17) and PRO III (Progressive Resolution Optimizer V 10.0.28) used for optimized algorithm of VAMT. A phantom for experiment virtually created at treatment planning system, 30x30x30 cm sized, homogeneous density (HU: 0) and heterogeneous density that inserted air assumed material (HU: -1,000). Apply to clinical treatment planning on the basis of general treatment planning feature analyzed with Phantom planning. In homogeneous density phantom, PBC and AAA show 65.2% PDD (6 MV, 10 cm) both, In heterogeneous density phantom, also show similar PDD value before meet with low density material, but they show different dose curve in air territory, PDD 10 cm showed 75%, 73% each after penetrate phantom. 3D treatment plan in same MU, AAA treatment planning shows low dose at Lung included area. 2D POP treatment plan with 15 MV of cervical vertebral region include trachea and lung area, Conformity Index (ICRU 62) is 0.95 in PBC calculation and 0.93 in AAA. DVO DVH and Dose calculation DVH are showed equal value in IMRT treatment plan. But AAA calculation shows lack of dose compared with DVO result which is satisfactory condition. Optimizing VMAT treatment plans using PRO II obtained results were satisfactory, but lower density area showed lack of dose in dose calculations. PRO III, but optimizing the dose calculation results were similar with optimized the same conditions once more. In this study, do not judge the rightness of the dose

  12. Stochastic Predictions of Cell Kill During Stereotactic Ablative Radiation Therapy: Do Hypoxia and Reoxygenation Really Matter?

    Energy Technology Data Exchange (ETDEWEB)

    Harriss-Phillips, Wendy M., E-mail: wharrphil@gmail.com [Department of Medical Physics, Royal Adelaide Hospital, Adelaide, South Australia (Australia); School of Chemistry and Physics, University of Adelaide, Adelaide, South Australia (Australia); Bezak, Eva [School of Chemistry and Physics, University of Adelaide, Adelaide, South Australia (Australia); International Centre for Allied Health Evidence, University of South Australia, Adelaide, South Australia (Australia); Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia (Australia); Potter, Andrew [Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, South Australia (Australia); Adelaide Radiotherapy Centre, Genesis CancerCare, Adelaide, South Australia (Australia)

    2016-07-15

    Purpose: To simulate stereotactic ablative radiation therapy on hypoxic and well-oxygenated in silico tumors, incorporating probabilistic parameter distributions and linear-quadratic versus linear-quadratic-cubic methodology and the evaluation of optimal fractionation schemes using biological effective dose (BED{sub α/β=10} {sub or} {sub 3}) comparisons. Methods and Materials: A temporal tumor growth and radiation therapy algorithm simulated high-dose external beam radiation therapy using stochastic methods. Realistic biological proliferative cellular hierarchy and pO{sub 2} histograms were incorporated into the 10{sup 8}-cell tumor model, with randomized radiation therapy applied during continual cell proliferation and volume-based gradual tumor reoxygenation. Dose fractions ranged from 6-35 Gy, with predictive outcomes presented in terms of the total doses (converted to BED) required to eliminate all cells that could potentially regenerate the tumor. Results: Well-oxygenated tumor control BED{sub 10} outcomes were not significantly different for high-dose versus conventional radiation therapy (BED{sub 10}: 79-84 Gy; Equivalent Dose in 2 Gy fractions with α/β of 10: 66-70 Gy); however, total treatment times decreased from 7 down to 1-3 weeks. For hypoxic tumors, an additional 28 Gy (51 Gy BED{sub 10}) was required, with BED{sub 10} increasing with dose per fraction due to wasted dose in the final fraction. Fractions of 9 Gy compromised well for total treatment time and BED, with BED{sub 10}:BED{sub 3} of 84:176 Gy for oxic and 132:278 Gy for non-reoxygenating hypoxic tumors. Initial doses of 12 Gy followed by 6 Gy further increased the therapeutic ratio. When delivering ≥9 Gy per fraction, applying reoxygenation and/or linear-quadratic-cubic cell survival both affected tumor control doses by a significant 1-2 fractions. Conclusions: The complex temporal dynamics of tumor oxygenation combined with probabilistic cell kinetics in the modeling of

  13. Task-based image quality assessment in radiation therapy: initial characterization and demonstration with CT simulation images

    Science.gov (United States)

    Dolly, Steven R.; Anastasio, Mark A.; Yu, Lifeng; Li, Hua

    2017-03-01

    In current radiation therapy practice, image quality is still assessed subjectively or by utilizing physically-based metrics. Recently, a methodology for objective task-based image quality (IQ) assessment in radiation therapy was proposed by Barrett et al.1 In this work, we present a comprehensive implementation and evaluation of this new IQ assessment methodology. A modular simulation framework was designed to perform an automated, computer-simulated end-to-end radiation therapy treatment. A fully simulated framework was created that utilizes new learning-based stochastic object models (SOM) to obtain known organ boundaries, generates a set of images directly from the numerical phantoms created with the SOM, and automates the image segmentation and treatment planning steps of a radiation therapy work ow. By use of this computational framework, therapeutic operating characteristic (TOC) curves can be computed and the area under the TOC curve (AUTOC) can be employed as a figure-of-merit to guide optimization of different components of the treatment planning process. The developed computational framework is employed to optimize X-ray CT pre-treatment imaging. We demonstrate that use of the radiation therapy-based-based IQ measures lead to different imaging parameters than obtained by use of physical-based measures.

  14. 21 CFR 892.5900 - X-ray radiation therapy system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false X-ray radiation therapy system. 892.5900 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5900 X-ray radiation therapy system. (a) Identification. An x-ray radiation therapy system is a device intended to produce and control x...

  15. 21 CFR 892.5710 - Radiation therapy beam-shaping block.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiation therapy beam-shaping block. 892.5710... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5710 Radiation therapy beam-shaping block. (a) Identification. A radiation therapy beam-shaping block is a device made of a highly...

  16. A prospective study of quality of life in breast cancer patients undergoing radiation therapy

    Directory of Open Access Journals (Sweden)

    Canhua Xiao, PhD, RN

    2016-01-01

    Conclusions: Radiation therapy did not worsen QOL in breast cancer patients. However, pre-radiation therapy patient characteristics including BMI and perceived stress may be used to identify women who may experience decreased physical and mental function during and up to 1 year after radiation therapy.

  17. Accreditation and quality assurance for Radiation Therapy Oncology Group: Multicenter clinical trials using Stereotactic Body Radiation Therapy in lung cancer.

    Science.gov (United States)

    Timmerman, Robert; Galvin, James; Michalski, Jeff; Straube, William; Ibbott, Geoffrey; Martin, Elizabeth; Abdulrahman, Ramzi; Swann, Suzanne; Fowler, Jack; Choy, Hak

    2006-01-01

    Starting in 2002, the Radiation Therapy Oncology Group in North America began the process of developing multicenter prospective trials in lung cancer using Stereotactic Body Radiation Therapy (SBRT). Much of the work was based on the prospective single institution trials from Indiana University that had been presented and published. In late 2004, RTOG 0236 using SBRT for medically inoperable patients with clinical stage I non-small cell lung cancer (NSCLC) was activated for accrual. Prior to activation, representatives from the Lung, Image-Guided Therapy, Physics, and Radiobiology Committees met on regular occasions to design the multicenter study and quality assurance measures. SBRT is not a black box, and the essence of the therapy had to be distilled via guidelines. Issues related to patient selection, method of dosimetry construction, equipment requirements, motion assessments and control, site accreditation, data exchange, and follow-up policies were worked out by compromise and consensus. RTOG 0236 has nearly completed its accrual. The Lung Committee has initiated the development of several other trials, each building on the last, to investigate the therapy in central tumors, in combinations with systemic therapy, in operable patients, and in lung metastases patients. The guidelines developed for RTOG 0236 will be refined to take advantage of more modern innovations including heterogeneity corrections and intensity modulation when appropriate. The development of RTOG 0618 using SBRT in operable patients with early stage NSCLC is a testament to both the enthusiasm from already published works and prospective multicenter clinical testing using SBRT techniques.

  18. Adjuvant and Salvage Radiation Therapy After Prostatectomy: American Society for Radiation Oncology/American Urological Association Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Valicenti, Richard K., E-mail: Richard.valicenti@ucdmc.ucdavis.edu [Department of Radiation Oncology, University of California, Davis School of Medicine, Davis, California (United States); Thompson, Ian [Department of Urology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States); Albertsen, Peter [Division of Urology, University of Connecticut Health Center, Farmington, Connecticut (United States); Davis, Brian J. [Department of Radiation Oncology, Mayo Medical School, Rochester, Minnesota (United States); Goldenberg, S. Larry [Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia (Canada); Wolf, J. Stuart [Department of Urology, University of Michigan, Ann Arbor, Michigan (United States); Sartor, Oliver [Department of Medicine and Urology, Tulane Medical School, New Orleans, Louisiana (United States); Klein, Eric [Glickman Urological Kidney Institute, Cleveland Clinic, Cleveland, Ohio (United States); Hahn, Carol [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Michalski, Jeff [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); Roach, Mack [Department of Radiation Oncology, University of California, San Francisco, San Francisco, California (United States); Faraday, Martha M. [Four Oaks, Inc (United States)

    2013-08-01

    Purpose: The purpose of this guideline was to provide a clinical framework for the use of radiation therapy after radical prostatectomy as adjuvant or salvage therapy. Methods and Materials: A systematic literature review using PubMed, Embase, and Cochrane database was conducted to identify peer-reviewed publications relevant to the use of radiation therapy after prostatectomy. The review yielded 294 articles; these publications were used to create the evidence-based guideline statements. Additional guidance is provided as Clinical Principles when insufficient evidence existed. Results: Guideline statements are provided for patient counseling, use of radiation therapy in the adjuvant and salvage contexts, defining biochemical recurrence, and conducting a restaging evaluation. Conclusions: Physicians should offer adjuvant radiation therapy to patients with adverse pathologic findings at prostatectomy (ie, seminal vesicle invastion, positive surgical margins, extraprostatic extension) and salvage radiation therapy to patients with prostate-specific antigen (PSA) or local recurrence after prostatectomy in whom there is no evidence of distant metastatic disease. The offer of radiation therapy should be made in the context of a thoughtful discussion of possible short- and long-term side effects of radiation therapy as well as the potential benefits of preventing recurrence. The decision to administer radiation therapy should be made by the patient and the multidisciplinary treatment team with full consideration of the patient's history, values, preferences, quality of life, and functional status. The American Society for Radiation Oncology and American Urological Association websites show this guideline in its entirety, including the full literature review.

  19. Accounting for radiation quality in heavy ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kellerer, A.M. [LMU, Muenchen (Germany). Radiobiological Inst.]|[Gesellschaft fuer Strahlen- und Umweltforschung, Muenchen (Germany). Inst. fuer Nuklearbiologie

    1997-09-01

    This introductory contribution outlines the need for models and their use in radiotherapy dose planning. The linear-quadratic dose relation is now predominantly used in therapy dose planning. In Section I it is linked to the earlier quantitative scheme for conventional radiotherapy. In Section II two major approaches are presented in a form that makes them comparable; the section can be read by itself, if this comparison alone is of interest. Models for therapy planning are tools, largely of empirical character; they do not need to elucidate unknown mechanisms of radiation action. The emphasis is, therefore, on the computational scheme, not on its interpretation. (orig.)

  20. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

    Energy Technology Data Exchange (ETDEWEB)

    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham [Andrew Love Cancer Centre, Geelong Hospital, Geelong, Victoria (Australia)

    2013-12-15

    Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques.

  1. Stereotactic body radiation therapy for metastasis to the adrenal glands.

    Science.gov (United States)

    Shiue, Kevin; Song, Andrew; Teh, Bin S; Ellis, Rodney J; Yao, Min; Mayr, Nina A; Huang, Zhibin; Sohn, Jason; Machtay, Mitchell; Lo, Simon S

    2012-12-01

    Many primary cancers can metastasize to the adrenal glands. Adrenalectomy via an open or laparoscopic approach is the current definitive treatment, but not all patients are eligible or wish to undergo surgery. There are only limited studies on the use of conventional radiation therapy for palliation of symptoms from adrenal metastasis. However, the advent of stereotactic body radiation therapy (SBRT) - also named stereotactic ablative radiotherapy for primary lung cancer, metastases to the lung, and metastases to the liver - have prompted some investigators to consider the use of SBRT for metastases to the adrenal glands. This review focuses on the emerging data on SBRT of metastasis to the adrenal glands, while also providing a brief discussion of the overall management of adrenal metastasis.

  2. Radiation therapy planning for early-stage Hodgkin lymphoma

    DEFF Research Database (Denmark)

    Maraldo, Maja V; Dabaja, Bouthaina S; Filippi, Andrea R

    2015-01-01

    PURPOSE: Early-stage Hodgkin lymphoma (HL) is a rare disease, and the location of lymphoma varies considerably between patients. Here, we evaluate the variability of radiation therapy (RT) plans among 5 International Lymphoma Radiation Oncology Group (ILROG) centers with regard to beam arrangements...... axillary disease, and 1 had disease in the neck only. The median age at diagnosis was 34 years (range, 21-74 years), and 5 patients were male. Of the resulting 50 treatment plans, 15 were planned with volumetric modulated arc therapy (1-4 arcs), 16 with intensity modulated RT (3-9 fields), and 19 with 3......, planning parameters, and estimated doses to the critical organs at risk (OARs). METHODS: Ten patients with stage I-II classic HL with masses of different sizes and locations were selected. On the basis of the clinical information, 5 ILROG centers were asked to create RT plans to a prescribed dose of 30...

  3. Palliative care and palliative radiation therapy education in radiation oncology: A survey of US radiation oncology program directors.

    Science.gov (United States)

    Wei, Randy L; Colbert, Lauren E; Jones, Joshua; Racsa, Margarita; Kane, Gabrielle; Lutz, Steve; Vapiwala, Neha; Dharmarajan, Kavita V

    The purpose of this study was to assess the state of palliative and supportive care (PSC) and palliative radiation therapy (RT) educational curricula in radiation oncology residency programs in the United States. We surveyed 87 program directors of radiation oncology residency programs in the United States between September 2015 and November 2015. An electronic survey on PSC and palliative RT education during residency was sent to all program directors. The survey consisted of questions on (1) perceived relevance of PSC and palliative RT to radiation oncology training, (2) formal didactic sessions on domains of PSC and palliative RT, (3) effective teaching formats for PSC and palliative RT education, and (4) perceived barriers for integrating PSC and palliative RT into the residency curriculum. A total of 57 responses (63%) was received. Most program directors agreed or strongly agreed that PSC (93%) and palliative radiation therapy (99%) are important competencies for radiation oncology residents and fellows; however, only 67% of residency programs had formal educational activities in principles and practice of PSC. Most programs had 1 or more hours of formal didactics on management of pain (67%), management of neuropathic pain (65%), and management of nausea and vomiting (63%); however, only 35%, 33%, and 30% had dedicated lectures on initial management of fatigue, assessing role of spirituality, and discussing advance care directives, respectively. Last, 85% of programs reported having a formal curriculum on palliative RT. Programs were most likely to have education on palliative radiation to brain, bone, and spine, but less likely on visceral, or skin, metastasis. Residency program directors believe that PSC and palliative RT are important competencies for their trainees and support increasing education in these 2 educational domains. Many residency programs have structured curricula on PSC and palliative radiation education, but room for improvement exists in

  4. Optimal Neutron Source & Beam Shaping Assembly for Boron Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    J. Vujic; E. Greenspan; W.E. Kastenber; Y. Karni; D. Regev; J.M. Verbeke, K.N. Leung; D. Chivers; S. Guess; L. Kim; W. Waldron; Y. Zhu

    2003-04-30

    There were three objectives to this project: (1) The development of the 2-D Swan code for the optimization of the nuclear design of facilities for medical applications of radiation, radiation shields, blankets of accelerator-driven systems, fusion facilities, etc. (2) Identification of the maximum beam quality that can be obtained for Boron Neutron Capture Therapy (BNCT) from different reactor-, and accelerator-based neutron sources. The optimal beam-shaping assembly (BSA) design for each neutron source was also to e obtained. (3) Feasibility assessment of a new neutron source for NCT and other medical and industrial applications. This source consists of a state-of-the-art proton or deuteron accelerator driving and inherently safe, proliferation resistant, small subcritical fission assembly.

  5. Optimal Neutron Source and Beam Shaping Assembly for Boron Neutron Capture Therapy

    CERN Document Server

    Vujic, J L; Greenspan, E; Guess, S; Karni, Y; Kastenber, W E; Kim, L; Leung, K N; Regev, D; Verbeke, J M; Waldron, W L; Zhu, Y

    2003-01-01

    There were three objectives to this project: (1) The development of the 2-D Swan code for the optimization of the nuclear design of facilities for medical applications of radiation, radiation shields, blankets of accelerator-driven systems, fusion facilities, etc. (2) Identification of the maximum beam quality that can be obtained for Boron Neutron Capture Therapy (BNCT) from different reactor-, and accelerator-based neutron sources. The optimal beam-shaping assembly (BSA) design for each neutron source was also to e obtained. (3) Feasibility assessment of a new neutron source for NCT and other medical and industrial applications. This source consists of a state-of-the-art proton or deuteron accelerator driving and inherently safe, proliferation resistant, small subcritical fission assembly.

  6. WE-B-BRD-02: MR Simulation for Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, K. [Deparment of Radiation Oncology, University of California Los Angeles (United States)

    2015-06-15

    The use of MRI in radiation therapy is rapidly increasing. Applications vary from the MRI simulator, to the MRI fused with CT, and to the integrated MRI+RT system. Compared with the standard MRI QA, a broader scope of QA features has to be defined in order to maximize the benefits of using MRI in radiation therapy. These QA features include geometric fidelity, image registration, motion management, cross-system alignment, and hardware interference. Advanced MRI techniques require a specific type of QA, as they are being widely used in radiation therapy planning, dose calculations, post-implant dosimetry, and prognoses. A vigorous and adaptive QA program is crucial to defining the responsibility of the entire radiation therapy group and detecting deviations from the performance of high-quality treatment. As a drastic departure from CT simulation, MRI simulation requires changes in the work flow of treatment planning and image guidance. MRI guided radiotherapy platforms are being developed and commercialized to take the advantage of the advance in knowledge, technology and clinical experience. This symposium will from an educational perspective discuss the scope and specific issues related to MRI guided radiotherapy. Learning Objectives: Understand the difference between a standard and a radiotherapy-specific MRI QA program. Understand the effects of MRI artifacts (geometric distortion and motion) on radiotherapy. Understand advanced MRI techniques (ultrashort echo, fast MRI including dynamic MRI and 4DMRI, diffusion, perfusion, and MRS) and related QA. Understand the methods to prepare MRI for treatment planning (electron density assignment, multimodality image registration, segmentation and motion management). Current status of MRI guided treatment platforms. Dr. Jihong Wang has a research grant with Elekta-MRL project. Dr. Ke Sheng receives research grants from Varian Medical systems.

  7. Effects of radiation therapy on growing long bones

    Energy Technology Data Exchange (ETDEWEB)

    De Smet, A.A.; Kuhns, L.R.; Fayos, J.V.; Holt, J.F.

    1976-12-01

    Characteristic radiographic changes were seen in six of 14 children who received radiation therapy to the epiphyseal plate of a long bone. These changes, which include metaphyseal sclerosis, metaphyseal fraying, and epiphyseal plate widening, resemble rickets. In three patients, these changes were followed by development of a broad metaphyseal band of increased density. The absence of metaphyseal changes may indicate sterilization of cartilage cells and may be predictive of significant limb shortening.

  8. Implications of the Bystander and Abscopal Effects of Radiation Therapy.

    Science.gov (United States)

    Verma, Vivek; Lin, Steven H

    2016-10-01

    Siva and colleagues have demonstrated that localized thoracic radiation resulted in DNA damage at out-of-field sites. Although these interesting findings require validation, we discuss the important clinical implications of these data, especially in the era of immune therapies. Clin Cancer Res; 22(19); 4763-5. ©2016 AACRSee related article by Siva et al., p. 4817. ©2016 American Association for Cancer Research.

  9. Sick sinus syndrome as a complication of mediastinal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pohjola-Sintonen, S.; Toetterman, K.J.K.; Kupari, M. (Helsinki Univ. Central Hospital (Finland))

    1990-06-01

    A 33-year-old man who had received mediastinal radiation therapy for Hodgkin's disease 12 years earlier developed a symptomatic sick sinus syndrome requiring the implantation of a permanent pacemaker. The sick sinus syndrome and a finding of an occult constrictive pericarditis were considered to be due to the previous mediastinal irradiation. A ventricular pacemaker was chosen because mediastinal radiotherapy also increases the risk of developing atrioventricular conduction defects.

  10. Definitive radiation therapy for infiltrative thyroid carcinoma in dogs.

    Science.gov (United States)

    Pack, L; Roberts, R E; Dawson, S D; Dookwah, H D

    2001-01-01

    The medical records of eight dogs with histopathologically confirmed infiltrative thyroid carcinoma treated with external beam radiation were reviewed and a retrospective analysis of survival and local tumor control were performed. The dogs received a definitive radiotherapy protocol of 46.8-48 Gray. All dogs had a reduction in tumor size to a clinically undetectable level on follow up examinations. Kaplan-Meier analysis indicated a median survival time of 24.5 months. Pulmonary metastasis was detected in three dogs and one of these dogs had concurrent bone metastasis. One dog had bone metastasis alone. Two dogs were alive at the censor. This study suggests that fractionated, definitive radiation therapy using multiple, moderate doses of radiation is an effective treatment for local control of invasive thyroid carcinoma in dogs.

  11. Towards magnetic resonance imaging guided radiation therapy (MRIgRT)

    Science.gov (United States)

    Stanescu, Teodor Marius

    The goal of this work is to address key aspects of the magnetic resonance imaging guided radiation therapy (MRIgRT) process of cancer sites. MRIgRT is implemented by using a system comprised of a magnetic resonance imaging (MRI) scanner coupled with a radiation source, in our case a radiotherapy accelerator (Linac). The potential benefits of MRIgRT are the real-time tracking of the tumor and neighbouring healthy anatomy during treatment irradiation leading to on-line treatment plan optimization. Ultimately, this results in an increased accuracy and efficiency of the overall treatment process. A large research effort is conducted at Cross Cancer Institute to develop a hybrid MRI-Linac system consisting of a bi-planar 0.2 T permanent magnet coupled with a 6 MV Linac. The present work is part of this project and aims to address the following key components: (a) magnetic shielding and dosimetric effects of the MRI-Linac system, (b) measure and correction of scanner-related MR image distortions, and (c) MRI-based treatment planning procedure for intracranial lesions. The first two components are essential for the optimal construction and operation of the MRI-Linac system while the third one represents a direct application of the system. The linac passive shielding was achieved by (a) adding two 10 cm thick steel (1020) plates placed at a distance of 10 cm from the structure on opposite sides of the magnet; and (b) a box lined with a 1 mm MuMetal(TM) wall surrounding the Linac. For our proposed MRI-Linac configuration (i.e. 0.2 T field and rotating bi-planar geometry) the maximum dose difference from zero magnetic field case was found to be within 6% and 12% in a water and water-lung-water phantom, respectively. We developed an image system distortion correction method for MRI that relies on adaptive thresholding and an iterative algorithm to determine the 3D distortion field. Applying this technique the residual image distortions were reduced to within the voxel

  12. Sparing of tissue by using micro-slit-beam radiation therapy reduces neurotoxicity compared with broad-beam radiation therapy.

    Science.gov (United States)

    Mukumoto, Naritoshi; Nakayama, Masao; Akasaka, Hiroaki; Shimizu, Yasuyuki; Osuga, Saki; Miyawaki, Daisuke; Yoshida, Kenji; Ejima, Yasuo; Miura, Yasushi; Umetani, Keiji; Kondoh, Takeshi; Sasaki, Ryohei

    2017-01-01

    Micro-slit-beam radiation therapy (MRT) using synchrotron-generated X-ray beams allows for extremely high-dose irradiation. However, the toxicity of MRT in central nervous system (CNS) use is still unknown. To gather baseline toxicological data, we evaluated mortality in normal mice following CNS-targeted MRT. Male C57BL/6 J mice were head-fixed in a stereotaxic frame. Synchrotron X-ray-beam radiation was provided by the SPring-8 BL28B2 beam-line. For MRT, radiation was delivered to groups of mice in a 10 × 12 mm unidirectional array consisting of 25-μm-wide beams spaced 100, 200 or 300 μm apart; another group of mice received the equivalent broad-beam radiation therapy (BRT) for comparison. Peak and valley dose rates of the MRT were 120 and 0.7 Gy/s, respectively. Delivered doses were 96-960 Gy for MRT, and 24-120 Gy for BRT. Mortality was monitored for 90 days post-irradiation. Brain tissue was stained using hematoxylin and eosin to evaluate neural structure. Demyelination was evaluated by Klüver-Barrera staining. The LD50 and LD100 when using MRT were 600 Gy and 720 Gy, respectively, and when using BRT they were 80 Gy and 96 Gy, respectively. In MRT, mortality decreased as the center-to-center beam spacing increased from 100 μm to 300 μm. Cortical architecture was well preserved in MRT, whereas BRT induced various degrees of cerebral hemorrhage and demyelination. MRT was able to deliver extremely high doses of radiation, while still minimizing neuronal death. The valley doses, influenced by beam spacing and irradiated dose, could represent important survival factors for MRT. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  13. Hyperbaric oxygen therapy for refractory radiation-induced hemorrhagic cystitis.

    Science.gov (United States)

    Ribeiro de Oliveira, Tiago M; Carmelo Romão, António J; Gamito Guerreiro, Francisco M; Matos Lopes, Tomé M

    2015-10-01

    To analyze the efficacy of hyperbaric oxygen for the treatment of radiation-induced hemorrhagic cystitis and to identify factors associated with successful treatment. Clinical records from 176 patients with refractory radiation-induced hemorrhagic cystitis treated at the Portuguese Navy Center for Underwater and Hyperbaric Medicine, during a 15-year period, were retrospectively analyzed. Evolution of macroscopic hematuria was used to analyze treatment efficacy and correlated with other external variables. From a total of 176 treated patients, 23.9% evidenced other radiation-induced soft tissue lesions. After an average on 37 sessions, 89.8% of patients showed resolution of hematuria, with only 1.7% of adverse events. In our sample, hematuria resolution after treatment with hyperbaric oxygen was statistically associated to the need for transfusion therapy (P = 0.026) and the number of sessions of hyperbaric oxygen (P = 0.042). No relationship was found with the remaining variables. Refractory radiation-induced hemorrhagic cystitis can be successfully and safely treated with hyperbaric oxygen. Treatment effectiveness seems to be correlated with the need for transfusion therapy and the number of sessions performed. © 2015 The Japanese Urological Association.

  14. Brachytherapy with an improved MammoSite Radiation Therapy System

    Science.gov (United States)

    Karthik, Nanda; Keppel, Cynthia; Nazaryan, Vahagn

    2007-03-01

    Accelerated partial breast irradiation treatment utilizing the MammoSite Radiation Therapy System (MRTS) is becoming increasingly popular. Clinical studies show excellent results for disease control and localization, as well as for cosmesis. Several Phase I, II, and III clinical trials have found significant association between skin spacing and cosmetic results after treatment with MRTS. As a result, patients with skin spacing less then 7 mm are not recommended to undergo this treatment. We have developed a practical innovation to the MammoSite brachytherapy methodology that is directed to overcome the skin spacing problem. The idea is to partially shield the radiation dose to the skin where the skin spacing is less then 7 mm, thereby protecting the skin from radiation damage. Our innovation to the MRTS will allow better cosmetic outcome in breast conserving therapy (BCT), and will furthermore allow more women to take advantage of BCT. Reduction in skin radiation exposure is particularly important for patients also undergoing adjuvant chemotherapy. We will present the method and preliminary laboratory and Monte Carlo simulation results.

  15. The Role of Postoperative Pelvic Radiation Therapy in Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Yong Chan; Kim, Jae Sung; Yun, Hyong Geun; Ha, Sung Whan; Park, Charn Il [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1991-06-15

    To evaluate the role of postoperative pelvic radiation therapy in rectal cancer, a retrospective analysis was done on 189 patients with modified Astler-Coller stages B2+3, C1, and C2+3 who were treated from February 1979 to June 1986. Forty-seven patients were staged as B2+3, 17 as C1, and 125 as C2+3. As a curative resection, 41 received low anterior resection, 143 received abdomino-perineal resection, and five received pelvic exenteration. The survival and disease-free survival rates of the total patients at five year were 45.3% and 44.1%, respectively. The stage was an important prognostic factor for survival and disease-free survival: the survival rates at five year were 55.7% in B2+3, 65.7% in C1, and 36.4% in C2+3, respectively (p<0.01). The liver was the most frequently involved organ of recurrence followed by the lung and the perineum. The patients who received low anterior resection achieved better disease-free survival but were more prone to late radiation bowel morbidities than those who received abdominoperineal resection. Postoperative pelvic radiation therapy proved to be effective in locoregional disease control but did not prevent the appearance of distant metastasis, which was of major concern in advanced stages. Patterns of treatment failure, and factors relating to radiation morbidity are discussed, and therapeutic options for better results are proposed.

  16. Martian Radiative Transfer Modeling Using the Optimal Spectral Sampling Method

    Science.gov (United States)

    Eluszkiewicz, J.; Cady-Pereira, K.; Uymin, G.; Moncet, J.-L.

    2005-01-01

    The large volume of existing and planned infrared observations of Mars have prompted the development of a new martian radiative transfer model that could be used in the retrievals of atmospheric and surface properties. The model is based on the Optimal Spectral Sampling (OSS) method [1]. The method is a fast and accurate monochromatic technique applicable to a wide range of remote sensing platforms (from microwave to UV) and was originally developed for the real-time processing of infrared and microwave data acquired by instruments aboard the satellites forming part of the next-generation global weather satellite system NPOESS (National Polarorbiting Operational Satellite System) [2]. As part of our on-going research related to the radiative properties of the martian polar caps, we have begun the development of a martian OSS model with the goal of using it to perform self-consistent atmospheric corrections necessary to retrieve caps emissivity from the Thermal Emission Spectrometer (TES) spectra. While the caps will provide the initial focus area for applying the new model, it is hoped that the model will be of interest to the wider Mars remote sensing community.

  17. Approximated segmentation considering technical and dosimetric constraints in intensity-modulated radiation therapy with electrons

    CERN Document Server

    Kiesel, Antje

    2010-01-01

    In intensity-modulated radiation therapy, optimal intensity distributions of incoming beams are decomposed into linear combinations of leaf openings of a multileaf collimator (segments). In order to avoid inefficient dose delivery, the decomposition should satisfy a number of dosimetric constraints due to suboptimal dose characteristics of small segments. However, exact decomposition with dosimetric constraints is only in limited cases possible. The present work introduces new heuristic segmentation algorithms for the following optimization problem: Find a segmentation of an approximated matrix using only allowed fields and minimize the approximation error. Finally, the decomposition algorithms were implemented into an optimization programme in order to examine the assumptions of the algorithms for a clinical example. As a result, identical dose distributions with much fewer segments and a significantly smaller number of monitor units could be achieved using dosimetric constraints. Consequently, the dose deli...

  18. Breast Cancer Biology: Clinical Implications for Breast Radiation Therapy.

    Science.gov (United States)

    Horton, Janet K; Jagsi, Reshma; Woodward, Wendy A; Ho, Alice

    2018-01-01

    Historically, prognosis and treatment decision making for breast cancer patients have been dictated by the anatomic extent of tumor spread. However, in recent years, "breast cancer" has proven to be a collection of unique phenotypes with distinct prognoses, patterns of failure, and treatment responses. Recent advances in biologically based assays and targeted therapies designed to exploit these unique phenotypes have profoundly altered systemic therapy practice patterns and treatment outcomes. Data associating locoregional outcomes with tumor biology are emerging. However, the likelihood of obtaining level I evidence for fundamental radiation therapy questions within each of the specific subtypes in the immediate future is low. As such, this review aims to summarize the existing data and provide practical context for the incorporation of breast tumor biology into clinical practice. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Imaging Changes in Pediatric Intracranial Ependymoma Patients Treated With Proton Beam Radiation Therapy Compared to Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, Jillian R. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Sato, Mariko; Chintagumpala, Murali [Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Texas Children' s Cancer Center, Houston, Texas (United States); Ketonen, Leena [Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jones, Jeremy Y. [Department of Pediatric Radiology, Texas Children' s Hospital, Houston, Texas (United States); Allen, Pamela K. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Paulino, Arnold C. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Texas Children' s Cancer Center, Houston, Texas (United States); Okcu, M. Fatih; Su, Jack M. [Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Texas Children' s Cancer Center, Houston, Texas (United States); Weinberg, Jeffrey [Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Boehling, Nicholas S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Khatua, Soumen [Department of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Adesina, Adekunle [Department of Pathology, Baylor College of Medicine, Texas Children' s Hospital, Houston, Texas (United States); Dauser, Robert; Whitehead, William E. [Department of Neurosurgery, Texas Children' s Hospital, Houston, Texas (United States); Mahajan, Anita, E-mail: amahajan@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-09-01

    Purpose: The clinical significance of magnetic resonance imaging (MRI) changes after radiation therapy (RT) in children with ependymoma is not well defined. We compared imaging changes following proton beam radiation therapy (PBRT) to those after photon-based intensity modulated RT (IMRT). Methods and Materials: Seventy-two patients with nonmetastatic intracranial ependymoma who received postoperative RT (37 PBRT, 35 IMRT) were analyzed retrospectively. MRI images were reviewed by 2 neuroradiologists. Results: Sixteen PBRT patients (43%) developed postradiation MRI changes at 3.8 months (median) with resolution by 6.1 months. Six IMRT patients (17%) developed changes at 5.3 months (median) with 8.3 months to resolution. Mean age at radiation was 4.4 and 6.9 years for PBRT and IMRT, respectively (P=.06). Age at diagnosis (>3 years) and time of radiation (≥3 years) was associated with fewer imaging changes on univariate analysis (odds ratio [OR]: 0.35, P=.048; OR: 0.36, P=.05). PBRT (compared to IMRT) was associated with more frequent imaging changes, both on univariate (OR: 3.68, P=.019) and multivariate (OR: 3.89, P=.024) analyses. Seven (3 IMRT, 4 PBRT) of 22 patients with changes had symptoms requiring intervention. Most patients were treated with steroids; some PBRT patients also received bevacizumab and hyperbaric oxygen therapy. None of the IMRT patients had lasting deficits, but 2 patients died from recurrent disease. Three PBRT patients had persistent neurological deficits, and 1 child died secondarily to complications from radiation necrosis. Conclusions: Postradiation MRI changes are more common with PBRT and in patients less than 3 years of age at diagnosis and treatment. It is difficult to predict causes for development of imaging changes that progress to clinical significance. These changes are usually self-limiting, but some require medical intervention, especially those involving the brainstem.

  20. Analysis of radiation pneumonitis outside the radiation field in breast conserving therapy for early breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ogo, Etsuyo; Fujimoto, Kiminori; Hayabuchi, Naofumi [Kurume Univ., Fukuoka (Japan). School of Medicine] (and others)

    2002-02-01

    In a retrospective study of radiation-induced pulmonary changes for patients with breast conserving therapy for early breast cancer, we sent questionnaires to the main hospitals in Japan. In this study, we analyzed pulmonary changes after tangential whole-breast irradiation. The purpose of this study was to determine the incidence and risk factors for radiation pneumonitis outside the radiation field. The questionnaires included patients data, therapy data, and lung injury information between August 1999 and May 2000. On the first questionnaires, answer letters were received from 107 institutions out of 158 (67.7%). On the second questionnaires, response rate (hospitals which had radiation pneumonitis outside the radiation field) was 21.7% (23/106). We could find no risk factors of this type of pneumonitis. We suggested that lung irradiation might trigger this type of pneumonitis which is clinically similar to BOOP (bronchiolitis obliterans organizing pneumonia). It developed in 1.5-2.1% among the patients with breast conserving surgery and tangential whole-breast irradiation. And it is likely appeared within 6 months after radiotherapy. (author)

  1. Evaluation of patients' engagement in radiation therapy safety.

    Science.gov (United States)

    Pernet, A; Mollo, V; Bibault, J-E; Giraud, P

    2016-12-01

    Treatment safety has become a priority in health policies after several incidents occurred around the world in radiation oncology departments. The aim of this study was to analyse the patients' contribution in that field and to understand which actions empower the patient in that regard. Several methods were used in a general hospital and in a comprehensive cancer centre to analyse the activities of the radiation therapists and the patients and the interactions between them: treatment session observations, semidirective interviews with radiation therapists and patients, self and alloconfrontation with radiation therapists and explanatory interviews with patients. Cooperation of the patients in treatment safety acts as an additional step that contributes to safer treatments. Radiation therapy sessions are a creative opportunity for the patient to observe, learn and analyse what is happening. Changes between treatment sessions are a source of anxiety for the patients. This study highlights the factors that favour the patients' participation. A trusting relationship and support from the health professionals can be leveraged in that manner. There is a common will shared between the patients and the health professionals towards better treatment safety. The cooperation is still not well-known and underused. This empowerment of the patient cannot be mandatory but should be promoted and developed. Copyright © 2016. Published by Elsevier SAS.

  2. Current status of radiation therapy. Evidence-based medicine (EBM) of radiation therapy. Non-Hodgkin's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Oguchi, Masahiko; Gomi, Koutaro [Japanese Foundation for Cancer Research, Tokyo (Japan). Hospital; Shikama, Naoto [Shinshu Univ., Matsumoto, Nagano (Japan). Hospital

    2002-04-01

    Non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of lympho-proliferative disorders, mainly originating in lymphoid tissues and other extranodal organs, with different patterns of behavior. Prognosis depends on the histo-pathologic type, prognostic factors, and treatment. According to the WHO classification (2001), the NHLs are divided into two prognostic groups: the indolent lymphomas (follicular lymphoma, marginal zone B-cell lymphoma, etc.) and the aggressive lymphomas (diffuse large B-cell lymphoma, peripheral T-cell lymphoma, etc.). Indolent NHLs have a good prognosis, with median survival as long as 10 years, and early stage (I and II) indolent NHLs can be treated with radiation therapy alone, with 70% to 90% 5-year overall survival rates. The aggressive NHLs have shorter natural histories, but the number of patients cured with intensive chemotherapy currently is increasing. In general, overall survival at 5 years is approximately 50% to 60%. Patients with stage I and contiguous stage II aggressive NHLs enjoy excellent survival rates when treated with a combined modality including chemotherapy (CHOP) and radiation therapy. The radiation dose for NHLs varies from 25 to 50 Gy and is dependent on pathologic type and the organs at risk. Radiation fields are basically limited to involved regions or extended to immediately adjacent sites. Localized presentations of extranodal NHLs can be treated with involved-field techniques with significant success. However, the long-term adverse reactions must be considered carefully. (author)

  3. Radiation-induced myocardial perfusion abnormalities in breast cancer patients following external beam radiation therapy

    Directory of Open Access Journals (Sweden)

    Mohammad Eftekhari

    2015-01-01

    Full Text Available Objective(s: Radiation therapy for breast cancer can induce myocardial capillary injury and increase cardiovascular morbidity and mortality. A prospective cohort was conducted to study the prevalence of myocardial perfusion abnormalities following radiation therapy of left-sided breast cancer patients as compared to those with right–sided cancer. Methods: To minimize potential confounding factors, only those patients with low 10-year risk of coronary artery disease (based on Framingham risk scoring were included. All patients were initially treated by modified radical mastectomy and then were managed by postoperative 3D Conformal Radiation Therapy (CRT to the surgical bed with an additional 1-cm margin, delivered by 46-50 Gy (in 2 Gy daily fractions over a 5-week course. The same dose-adjusted chemotherapy regimen (including anthracyclines, cyclophosphamide and taxol was given to all patients. Six months after radiation therapy, all patients underwent cardiac SPECT for the evaluation of myocardial perfusion. Results: A total of 71 patients with a mean age of 45.3±7.2 years [35 patients with leftsided breast cancer (exposed and 36 patients with right-sided cancer (controls] were enrolled. Dose-volume histogram (DVH [showing the percentage of the heart exposed to >50% of radiation] was significantly higher in patients with left-sided breast cancer. Visual interpretation detected perfusion abnormalities in 42.9% of cases and 16.7% of controls (P=0.02, Odds ratio=1.46. In semiquantitative segmental analysis, only apical (28.6% versus 8.3%, P=0.03 and anterolateral (17.1% versus 2.8%, P=0.049 walls showed significantly reduced myocardial perfusion in the exposed group. Summed Stress Score (SSS of>3 was observed in twelve cases (34.3%, while in five of the controls (13.9%,(Odds ratio=1.3. There was no significant difference between the groups regarding left ventricular ejection fraction. Conclusion: The risk of radiation induced myocardial

  4. Anonymization of DICOM electronic medical records for radiation therapy.

    Science.gov (United States)

    Newhauser, Wayne; Jones, Timothy; Swerdloff, Stuart; Newhauser, Warren; Cilia, Mark; Carver, Robert; Halloran, Andy; Zhang, Rui

    2014-10-01

    Electronic medical records (EMR) and treatment plans are used in research on patient outcomes and radiation effects. In many situations researchers must remove protected health information (PHI) from EMRs. The literature contains several studies describing the anonymization of generic Digital Imaging and Communication in Medicine (DICOM) files and DICOM image sets but no publications were found that discuss the anonymization of DICOM radiation therapy plans, a key component of an EMR in a cancer clinic. In addition to this we were unable to find a commercial software tool that met the minimum requirements for anonymization and preservation of data integrity for radiation therapy research. The purpose of this study was to develop a prototype software code to meet the requirements for the anonymization of radiation therapy treatment plans and to develop a way to validate that code and demonstrate that it properly anonymized treatment plans and preserved data integrity. We extended an open-source code to process all relevant PHI and to allow for the automatic anonymization of multiple EMRs. The prototype code successfully anonymized multiple treatment plans in less than 1min/patient. We also tested commercial optical character recognition (OCR) algorithms for the detection of burned-in text on the images, but they were unable to reliably recognize text. In addition, we developed and tested an image filtering algorithm that allowed us to isolate and redact alpha-numeric text from a test radiograph. Validation tests verified that PHI was anonymized and data integrity, such as the relationship between DICOM unique identifiers (UID) was preserved. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. A point kernel algorithm for microbeam radiation therapy

    Science.gov (United States)

    Debus, Charlotte; Oelfke, Uwe; Bartzsch, Stefan

    2017-11-01

    Microbeam radiation therapy (MRT) is a treatment approach in radiation therapy where the treatment field is spatially fractionated into arrays of a few tens of micrometre wide planar beams of unusually high peak doses separated by low dose regions of several hundred micrometre width. In preclinical studies, this treatment approach has proven to spare normal tissue more effectively than conventional radiation therapy, while being equally efficient in tumour control. So far dose calculations in MRT, a prerequisite for future clinical applications are based on Monte Carlo simulations. However, they are computationally expensive, since scoring volumes have to be small. In this article a kernel based dose calculation algorithm is presented that splits the calculation into photon and electron mediated energy transport, and performs the calculation of peak and valley doses in typical MRT treatment fields within a few minutes. Kernels are analytically calculated depending on the energy spectrum and material composition. In various homogeneous materials peak, valley doses and microbeam profiles are calculated and compared to Monte Carlo simulations. For a microbeam exposure of an anthropomorphic head phantom calculated dose values are compared to measurements and Monte Carlo calculations. Except for regions close to material interfaces calculated peak dose values match Monte Carlo results within 4% and valley dose values within 8% deviation. No significant differences are observed between profiles calculated by the kernel algorithm and Monte Carlo simulations. Measurements in the head phantom agree within 4% in the peak and within 10% in the valley region. The presented algorithm is attached to the treatment planning platform VIRTUOS. It was and is used for dose calculations in preclinical and pet-clinical trials at the biomedical beamline ID17 of the European synchrotron radiation facility in Grenoble, France.

  6. Survival times for canine intranasal sarcomas treated with radiation therapy: 86 cases (1996-2011).

    Science.gov (United States)

    Sones, Evan; Smith, Annette; Schleis, Stephanie; Brawner, William; Almond, Gregory; Taylor, Kathryn; Haney, Siobhan; Wypij, Jackie; Keyerleber, Michele; Arthur, Jennifer; Hamilton, Terrance; Lawrence, Jessica; Gieger, Tracy; Sellon, Rance; Wright, Zack

    2013-01-01

    Sarcomas comprise approximately one-third of canine intranasal tumors, however few veterinary studies have described survival times of dogs with histologic subtypes of sarcomas separately from other intranasal tumors. One objective of this study was to describe median survival times for dogs treated with radiation therapy for intranasal sarcomas. A second objective was to compare survival times for dogs treated with three radiation therapy protocols: daily-fractionated radiation therapy; Monday, Wednesday, and Friday fractionated radiation therapy; and palliative radiation therapy. Medical records were retrospectively reviewed for dogs that had been treated with radiation therapy for confirmed intranasal sarcoma. A total of 86 dogs met inclusion criteria. Overall median survival time for included dogs was 444 days. Median survival time for dogs with chondrosarcoma (n = 42) was 463 days, fibrosarcoma (n = 12) 379 days, osteosarcoma (n = 6) 624 days, and undifferentiated sarcoma (n = 22) 344 days. Dogs treated with daily-fractionated radiation therapy protocols; Monday, Wednesday and Friday fractionated radiation therapy protocols; and palliative radiation therapy protocols had median survival times of 641, 347, and 305 days, respectively. A significant difference in survival time was found for dogs receiving curative intent radiation therapy vs. palliative radiation therapy (P = 0.032). A significant difference in survival time was also found for dogs receiving daily-fractionated radiation therapy vs. Monday, Wednesday and Friday fractionated radiation therapy (P = 0.0134). Findings from this study support the use of curative intent radiation therapy for dogs with intranasal sarcoma. Future prospective, randomized trials are needed for confirmation of treatment benefits. © 2012 Veterinary Radiology & Ultrasound.

  7. Accuracy of marketing claims by providers of stereotactic radiation therapy.

    Science.gov (United States)

    Narang, Amol K; Lam, Edwin; Makary, Martin A; Deweese, Theodore L; Pawlik, Timothy M; Pronovost, Peter J; Herman, Joseph M

    2013-01-01

    Direct-to-consumer advertising by industry has been criticized for encouraging overuse of unproven therapies, but advertising by health care providers has not been as carefully scrutinized. Stereotactic radiation therapy is an emerging technology that has sparked controversy regarding the marketing campaigns of some manufacturers. Given that this technology is also being heavily advertised on the Web sites of health care providers, the accuracy of providers' marketing claims should be rigorously evaluated. We reviewed the Web sites of all U.S. hospitals and private practices that provide stereotactic radiation using two leading brands of stereotactic radiosurgery technology. Centers were identified by using data from the manufacturers. Centers without Web sites were excluded. The final study population consisted of 212 centers with online advertisements for stereotactic radiation. Web sites were evaluated for advertisements that were inconsistent with advertising guidelines provided by the American Medical Association. Most centers (76%) had individual pages dedicated to the marketing of their brand of stereotactic technology that frequently contained manufacturer-authored images (50%) or text (55%). Advertising for the treatment of tumors that have not been endorsed by professional societies was present on 66% of Web sites. Centers commonly claimed improved survival (22%), disease control (20%), quality of life (17%), and toxicity (43%) with stereotactic radiation. Although 40% of Web sites championed the center's regional expertise in delivering stereotactic treatments, only 15% of Web sites provided data to support their claims. Provider advertisements for stereotactic radiation were prominent and aggressive. Further investigation of provider advertising, its effects on quality of care, and potential oversight mechanisms is needed.

  8. Accuracy of Marketing Claims by Providers of Stereotactic Radiation Therapy

    Science.gov (United States)

    Narang, Amol K.; Lam, Edwin; Makary, Martin A.; DeWeese, Theodore L.; Pawlik, Timothy M.; Pronovost, Peter J.; Herman, Joseph M.

    2013-01-01

    Purpose: Direct-to-consumer advertising by industry has been criticized for encouraging overuse of unproven therapies, but advertising by health care providers has not been as carefully scrutinized. Stereotactic radiation therapy is an emerging technology that has sparked controversy regarding the marketing campaigns of some manufacturers. Given that this technology is also being heavily advertised on the Web sites of health care providers, the accuracy of providers' marketing claims should be rigorously evaluated. Methods: We reviewed the Web sites of all US hospitals and private practices that provide stereotactic radiation using two leading brands of stereotactic radiosurgery technology. Centers were identified by using data from the manufacturers. Centers without Web sites were excluded. The final study population consisted of 212 centers with online advertisements for stereotactic radiation. Web sites were evaluated for advertisements that were inconsistent with advertising guidelines provided by the American Medical Association. Results: Most centers (76%) had individual pages dedicated to the marketing of their brand of stereotactic technology that frequently contained manufacturer-authored images (50%) or text (55%). Advertising for the treatment of tumors that have not been endorsed by professional societies was present on 66% of Web sites. Centers commonly claimed improved survival (22%), disease control (20%), quality of life (17%), and toxicity (43%) with stereotactic radiation. Although 40% of Web sites championed the center's regional expertise in delivering stereotactic treatments, only 15% of Web sites provided data to support their claims. Conclusion: Provider advertisements for stereotactic radiation were prominent and aggressive. Further investigation of provider advertising, its effects on quality of care, and potential oversight mechanisms is needed. PMID:23633973

  9. Implementation of MRI gel dosimetry in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Baeck, S.Aa.J

    1998-12-01

    Gel dosimetry was used together with magnetic resonance imaging (MRI) to measure three-dimensional absorbed dose distributions in radiation therapy. Two different dosimeters were studied: ferrous- and monomer gel, based on the principles of radiation-induced oxidation and polymerisation, respectively. Single clinical electron and photon beams were evaluated and gel dose distributions were mainly within 2% of conventional detector results. The ferrous-gel was also used for clinical proton beams. A decrease in signal per absorbed dose was found close to the end of the range of the protons (15-20%). This effect was explained as a linear energy transfer dependence, further supported with Monte Carlo simulations. A method for analysing and comparing data from treatment planning system (TPS) and gel measurements was developed. The method enables a new pixel by pixel evaluation, isodose comparison and dose volume histogram verification. Two standard clinical radiation therapy procedures were examined using the developed TPS verification method. The treatment regimes included several beams of different radiation qualities. The TPS calculated data were in very good agreement with the dose distribution measured by the ferrous-gel. However, in a beam abutment region, larger dose difference was found. Beam adjustment errors and a minor TPS underestimation of the lateral scatter contribution outside the primary electron beam may explain the discrepancy. The overall uncertainty in the ferrous-gel dose determination was considerably reduced using an optimised MRI acquisition protocol and a new MRI scanner. The relative dose uncertainty was found to be better than 3.3% for all dose levels (95% confidence level). Using the method developed for comparing measured gel data with calculated treatment plans, the gel dosimetry method was proven to be a useful tool for radiation treatment planning verification 103 refs, 20 figs, 6 tabs

  10. A Population-Based Study of the Fractionation of Postlumpectomy Breast Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ashworth, Allison [Division of Cancer Care and Epidemiology, Queen' s University Cancer Research Institute, Kingston, Ontario (Canada); Cancer Center of Southeastern Ontario, Kingston, Ontario (Canada); Kong, Weidong [Division of Cancer Care and Epidemiology, Queen' s University Cancer Research Institute, Kingston, Ontario (Canada); Whelan, Timothy [Juravinski Cancer Center, Hamilton, Ontario (Canada); Mackillop, William J., E-mail: william.mackillop@krcc.on.ca [Division of Cancer Care and Epidemiology, Queen' s University Cancer Research Institute, Kingston, Ontario (Canada)

    2013-05-01

    Purpose: The optimal fractionation schedule of post lumpectomy radiation therapy remains controversial. The objective of this study was to describe the fractionation of post-lumpectomy radiation therapy (RT) in Ontario, before and after the seminal Ontario Clinical Oncology Group (OCOG) trial, which showed the equivalence of 16- and 25-fraction schedules. Methods and Materials: This was a retrospective cohort study conducted by linking electronic treatment records to a population-based cancer registry. The study population included all patients who underwent lumpectomy for invasive breast cancer in Ontario, Canada, between 1984 and 2008. Results: Over the study period, 41,747 breast cancer patients received post lumpectomy radiation therapy to the breast only. Both 16- and 25-fraction schedules were commonly used throughout the study period. In the early 1980s, shorter fractionation schedules were used in >80% of cases. Between 1985 and 1995, the proportion of patients treated with shorter fractionation decreased to 48%. After completion of the OCOG trial, shorter fractionation schemes were once again widely adopted across Ontario, and are currently used in about 71% of cases; however, large intercenter variations in fractionation persisted. Conclusions: The use of shorter schedules of post lumpectomy RT in Ontario increased after completion of the OCOG trial, but the trial had a less normative effect on practice than expected.

  11. Linear energy transfer incorporated intensity modulated proton therapy optimization

    Science.gov (United States)

    Cao, Wenhua; Khabazian, Azin; Yepes, Pablo P.; Lim, Gino; Poenisch, Falk; Grosshans, David R.; Mohan, Radhe

    2018-01-01

    The purpose of this study was to investigate the feasibility of incorporating linear energy transfer (LET) into the optimization of intensity modulated proton therapy (IMPT) plans. Because increased LET correlates with increased biological effectiveness of protons, high LETs in target volumes and low LETs in critical structures and normal tissues are preferred in an IMPT plan. However, if not explicitly incorporated into the optimization criteria, different IMPT plans may yield similar physical dose distributions but greatly different LET, specifically dose-averaged LET, distributions. Conventionally, the IMPT optimization criteria (or cost function) only includes dose-based objectives in which the relative biological effectiveness (RBE) is assumed to have a constant value of 1.1. In this study, we added LET-based objectives for maximizing LET in target volumes and minimizing LET in critical structures and normal tissues. Due to the fractional programming nature of the resulting model, we used a variable reformulation approach so that the optimization process is computationally equivalent to conventional IMPT optimization. In this study, five brain tumor patients who had been treated with proton therapy at our institution were selected. Two plans were created for each patient based on the proposed LET-incorporated optimization (LETOpt) and the conventional dose-based optimization (DoseOpt). The optimized plans were compared in terms of both dose (assuming a constant RBE of 1.1 as adopted in clinical practice) and LET. Both optimization approaches were able to generate comparable dose distributions. The LET-incorporated optimization achieved not only pronounced reduction of LET values in critical organs, such as brainstem and optic chiasm, but also increased LET in target volumes, compared to the conventional dose-based optimization. However, on occasion, there was a need to tradeoff the acceptability of dose and LET distributions. Our conclusion is that the

  12. Linear energy transfer incorporated intensity modulated proton therapy optimization.

    Science.gov (United States)

    Cao, Wenhua; Khabazian, Azin; Yepes, Pablo P; Lim, Gino J; Poenisch, Falk; Grosshans, David R; Mohan, Radhe

    2017-11-13

    The purpose of this study was to investigate the feasibility of incorporating linear energy transfer (LET) into the optimization of intensity modulated proton therapy (IMPT) plans. Because increased LET correlates with increased biological effectiveness of protons, high LETs in target volumes and low LETs in critical structures and normal tissues are preferred in an IMPT plan. However, if not explicitly incorporated into the optimization criteria, different IMPT plans may yield similar physical dose distributions but greatly different LET, specifically dose-averaged LET, distributions. Conventionally, the IMPT optimization criteria (or cost function) only includes dose-based objectives in which the relative biological effectiveness (RBE) is assumed to have a constant value of 1.1. In this study, we added LET-based objectives for maximizing LET in target volumes and minimizing LET in critical structures and normal tissues. Due to the fractional programming nature of the resulting model, we used a variable reformulation approach so that the optimization process is computationally equivalent to conventional IMPT optimization. In this study, five brain tumor patients who had been treated with proton therapy at our institution were selected. Two plans were created for each patient based on the proposed LET-incorporated optimization (LETOpt) and the conventional dose-based optimization (DoseOpt). The optimized plans were compared in terms of both dose (assuming a constant RBE of 1.1 as adopted in clinical practice) and LET. Both optimization approaches were able to generate comparable dose distributions. The LET-incorporated optimization achieved not only pronounced reduction of LET values in critical organs, such as brainstem and optic chiasm, but also increased LET in the target volumes, compared to the conventional dose-based optimization. However, on occasion, there was a need to tradeoff the acceptability of dose and LET distributions. Our conclusion is that the

  13. Novel approach to lung stereotactic body radiation therapy plan evaluation and delivery

    Science.gov (United States)

    Jurkovic, Ines-Ana

    clinically used margins especially for the very small tumor volumes. Found correlations and motion trajectory similarities as well as ability to achieve a good planar fit for the tumor motion paths lead to development of the novel predictive models based on data mining algorithms which would provide an automatic tool for the calculation of the extent of lung tumor motion characterized by its known location and size. Proposed solution has several advantages and high prediction accuracy. The goal of the Specific Aim 2 was to produce true four-dimensional step and shoot intensity modulated radiation therapy plans and make true four-dimensional delivery. Before four-dimensional dose accumulation was performed, used deformable image registration algorithm was assessed for its quality, accuracy and physicality. The optimal measures that may be used for the evaluation of the deformable registration accuracy of a four-dimensional computed tomography dataset were demonstrated. Next the effect of the four-dimensional computed tomography dose distribution reconstruction through the breathing phases and the influence of the chosen deformable registration method on the final result was investigated. Study showed that the accuracy of the deformable image registration algorithm is patient and location dependent, and it considerably influences the final four-dimensional dose distribution. At present, radiotherapy treatment planning evaluation is based for the most part on dosimetric plan performance, nevertheless, using radiobiological analysis to assess benefits of tumor control while limiting injury to normal tissues can be very beneficial. Therefore, Specific Aim 3 investigated the influence of breathing motion and deformable image registration method choice on the quality of delivered radiation therapy treatment for lung cancer patients through radiobiological analysis. Differences observed in dosimetric and radiobiological analysis of the 'four-dimensional' and 'four

  14. Adjuvant postoperative radiation therapy for carcinoma of the uterine cervix

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Ja; Moon, Hye Seong; Kim, Seung Cheol; Kim, Chong Il; Ahn, Jung Ja [College of Medicine, Ewha Womans Univ., Seoul (Korea, Republic of)

    2003-09-01

    This study was undertaken to evaluate the efficacy of postoperative radiotherapy, and to investigate the prognostic factors for FIGO stages IB-IIB cervical cancer patients who were treated with simple hysterectomy, or who had high-risk factors following radical hysterectomy and pelvic lymph node dissection. Between March 1986 and December 1998, 58 patients, with FIGO stages IB-IIB cervical cancer were included in this study, The indications for postoperative radiation therapy were based on the pathological findings, including lymph node metastasis, positive surgical margin, parametrial extension, Iymphovascular invasion, invasion of more than half the cervical stroma, uterine extension and the incidental finding of cervix cancer following simple hysterectomy. All patients received external pelvic radiotherapy, and 5 patients, received an additional intracavitary radiation therapy. The radiation dose from the external beam to the whole pelvis was 45 - 50 Gy. Vagina cuff irradiation was performed, after completion of the external beam irradiation, al a low-dose rate of CS-137, with the total dose of 4488-4932 chy (median: 4500 chy) at 5 mm depth from the vagina surface. The median follow-up period was 44 months (15-108 months), The 5-yr actuarial local control rate, distant free survival and disease-free survival rate were 98%, 95% and 94%, respectively. A univariate analysis of the clinical and pathological parameters revealed that the clinical stage (p=0.0145), status of vaginal resection margin (p=0.0002) and parametrial extension (p=0.0001) affected the disease-free survival. From a multivariate analysis, only a parametrial extension independently influenced the disease-free survival. Five patients (9%) experienced Grade 2 late treatment-related complications, such as radiation proctitis (1 patient), cystitis (3 patients) and lymphedema of the leg (1 patient). No patient had grade 3 or 4 complications. Our results indicate that postoperative radiation therapy can

  15. Failure of odontogenesis after chemo-radiation therapy for rhabdomyosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sun Young; Hong, Sung Woo; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    1998-02-15

    This report details a case of 8-year-old girl showing failure of odontogenesis after chemo-radiation therapy for rhabdomysarcoma at the age of 4. The observed results were as follows: 1. Past history revealed that she had received for a total radiation dose od 4430 cGy, 29 fractions in 6 weeks and chemotherapy with vincristine, actinomycin D and cytoxan, followed as maintenance phase for 2 years. 2. The patient was symptom-free and appointed for the treatment of multiple dental caries. 3. Oral examination showed hypoplastic enamel on whole erupted permanent teeth and showed retarded eruption. 4. Conventional radiograms showed failure of root development including abrupt cessation of root formation and root agenesis, and microdobtia, missing teeth, irregular enamel, dislocation of the impacted teeth. Additional finding showed good healing bone pattern on the left mandibular ramus and angle area. 5. Cehalometric analysis revealed failure of bite raising due to incomplete eruption of all the first molars and made it possible to suspect entrapped mandibular growth and then Class II tendency growth. 6. There was correlation between the time of chemo-radiation therapy and the damage of the teeth.

  16. Combined preoperative therapy for oral cancer with nedaplatin and radiation

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Masatoshi; Shibata, Akihiko; Hayashi, Munehiro [Nippon Dental Univ., Tokyo (Japan). Hospital] (and others)

    2002-03-01

    We performed preoperative combined therapy using nedaplatin (CDGP) and radiation in 12 patients with squamous cell carcinoma originating from the oral cavity and maxillary sinus, and examined for any adverse events that may have occurred during this therapeutic regimen. Regarding the irradiation, external irradiation utilizing a 6 MV linac (linear accelerator) at a dose of 2.0 Gy/day was performed 5 times a week, with the target total radiation dose set at 40 Gy. In addition, CDGP was intravenously administered 30 minutes before irradiation at a dose of 5 mg/m{sup 2}/day. Mucositis was observed in all 12 subjects, however, the severity was observed to be grade 1-2 with no major differences in comparison to the patients given standard radiation monotherapy. Two subjects developed grade 3 leucopenia and were thus given granulocyte colony stimulating factor (G-CSF). In addition, grade 2 and grade 3 thrombocytopenia were both observed in one subject each. The subject with grade 3 thrombocytopenia required a platelet transfusion during surgery. No marked changes in serum creatinine levels were noted. These findings are therefore considered to provide evidence supporting the safety of this combination therapy. (author)

  17. Radiation Physics and Chemistry in Heavy-ion Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Kimura, M.

    2007-12-01

    Full Text Available Heavy ions, such as carbon and oxygen ions, are classified as high-LET radiations, and produce a characteristic dose-depth distribution different from that of low-LET radiations such as γ-rays, xrays and electrons. Heavy ions lose less energy at the entrance to an irradiated biological system up to some depth than the low-LET radiations, while they deposit a large amount of dose within a very narrow range at a certain depth, producing the characteristic sharp peak called the Bragg peak. Therefore, by controlling the Bragg peak, it becomes possible to irradiate only the tumor region in a pin-point manner, while avoiding irradiation of the normal tissue, thus making heavyion therapy ideal for deep-seated tumor treatment. Clinical results on more than 2400 patients are very encouraging. However, very little is known about what is going on in terms of physics and chemistry inside the Bragg peak. In this paper the current status of our understanding of heavy-ion interactions and remaining problems of physics and chemistry for the heavy-ion treatment are explored, particularly in the Bragg peak region. Specially, the survey of the basic physical quantity, the mean energy required to form an ion pair (Wvalue for heavy ions of interest for radiotherapy is presented. Finally, the current clinical status of heavy-ion therapy is presented.

  18. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Luxemburgo Hospital, Mario Penna Institute, Belo Horizonte, MG (Brazil)

    2015-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  19. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Minas Gerais, MG (Brazil). Dept. de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Instituto Mario Penna, Minas Gerais, MG (Brazil). Hospital Luxemburgo

    2013-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  20. Percutaneous coronary intervention with optimal medical therapy vs. optimal medical therapy alone for patients with stable angina pectoris

    Directory of Open Access Journals (Sweden)

    Gorenoi, Vitali

    2011-01-01

    Full Text Available Scientific background: Stable Angina Pectoris (AP is a main syndrome of chronic coronary artery disease (CAD, a disease with enormous epidemiological and health economic relevance. Medical therapy and percutaneous coronary interventions (PCI are the most important methods used in the treatment of chronic CAD. Research questions: The evaluation addresses questions on medical efficacy, incremental cost-effectiveness as well as ethic, social and legal aspects in the use of PCI in CAD patients in comparison to optimal medical therapy alone. Methods: A systematic literature search was conducted in June 2010 in the electronic databases (MEDLINE, EMBASE etc. and was completed by a hand search. The medical analysis was initially based on systematic reviews of randomized controlled trials (RCT and was followed by the evaluation of RCT with use of current optimal medical therapy. The results of the RCT were combined using meta-analysis. The strength and the applicability of the determined evidence were appraised. The health economic analysis was initially focused on the published studies. Additionally, a health economic modelling was performed with clinical assumptions derived from the conducted meta-analysis and economic assumptions derived from the German Diagnosis Related Groups 2011. Results: Seven systematic reviews (applicability of the evidence low and three RCT with use of optimal medical therapy (applicability of the evidence for the endpoints AP and revascularisations moderate, for further endpoints high were included in the medical analysis. The results from RCT are used as a base of the evaluation. The routine use of the PCI reduces the proportion of patients with AP attacks in the follow-up after one and after three years in comparison with optimal medical therapy alone (evidence strength moderate; however, this effect was not demonstrated in the follow-up after five years (evidence strength low. The difference in effect in the follow

  1. Percutaneous coronary intervention with optimal medical therapy vs. optimal medical therapy alone for patients with stable angina pectoris.

    Science.gov (United States)

    Gorenoi, Vitali; Schönermark, Matthias P; Hagen, Anja

    2011-01-01

    Stable Angina Pectoris (AP) is a main syndrome of chronic coronary artery disease (CAD), a disease with enormous epidemiological and health economic relevance. Medical therapy and percutaneous coronary interventions (PCI) are the most important methods used in the treatment of chronic CAD. The evaluation addresses questions on medical efficacy, incremental cost-effectiveness as well as ethic, social and legal aspects in the use of PCI in CAD patients in comparison to optimal medical therapy alone. A systematic literature search was conducted in June 2010 in the electronic databases (MEDLINE, EMBASE etc.) and was completed by a hand search. The medical analysis was initially based on systematic reviews of randomized controlled trials (RCT) and was followed by the evaluation of RCT with use of current optimal medical therapy. The results of the RCT were combined using meta-analysis. The strength and the applicability of the determined evidence were appraised. The health economic analysis was initially focused on the published studies. Additionally, a health economic modelling was performed with clinical assumptions derived from the conducted meta-analysis and economic assumptions derived from the German Diagnosis Related Groups 2011. Seven systematic reviews (applicability of the evidence low) and three RCT with use of optimal medical therapy (applicability of the evidence for the endpoints AP and revascularisations moderate, for further endpoints high) were included in the medical analysis. The results from RCT are used as a base of the evaluation. The routine use of the PCI reduces the proportion of patients with AP attacks in the follow-up after one and after three years in comparison with optimal medical therapy alone (evidence strength moderate); however, this effect was not demonstrated in the follow-up after five years (evidence strength low). The difference in effect in the follow-up after four to five years was not found for the further investigated clinical

  2. Endoscopic diode laser therapy for chronic radiation proctitis.

    Science.gov (United States)

    Polese, Lino; Marini, Lucia; Rizzato, Roberto; Picardi, Edgardo; Merigliano, Stefano

    2018-01-01

    The purpose of this study is to determine the effectiveness of endoscopic diode laser therapy in patients presenting rectal bleeding due to chronic radiation proctitis (CRP). A retrospective analysis of CRP patients who underwent diode laser therapy in a single institution between 2010 and 2016 was carried out. The patients were treated by non-contact fibers without sedation in an outpatient setting. Fourteen patients (median age 77, range 73-87 years) diagnosed with CRP who had undergone high-dose radiotherapy for prostatic cancer and who presented with rectal bleeding were included. Six required blood transfusions. Antiplatelet (three patients) and anticoagulant (two patients) therapy was not suspended during the treatments. The patients underwent a median of two sessions; overall, a mean of 1684 J of laser energy per session was used. Bleeding was resolved in 10/14 (71%) patients, and other two patients showed improvement (93%). Only one patient, who did not complete the treatment, required blood transfusions after laser therapy; no complications were noted during or after the procedures. Study findings demonstrated that endoscopic non-contact diode laser treatment is safe and effective in CRP patients, even in those receiving antiplatelet and/or anticoagulant therapy.

  3. Analysis of Prostate Deformation during a Course of Radiation Therapy for Prostate Cancer.

    Science.gov (United States)

    Nakazawa, Takuya; Tateoka, Kunihiko; Saito, Yuichi; Abe, Tadanori; Yano, Masaki; Yaegashi, Yuji; Narimatsu, Hirokazu; Fujimoto, Kazunori; Nakata, Akihiro; Nakata, Kensei; Someya, Masanori; Hori, Masakazu; Hareyama, Masato; Sakata, Koichi

    2015-01-01

    Accurate analysis of the correlation between deformation of the prostate and displacement of its center of gravity (CoG) is important for efficient radiation therapy for prostate cancer. In this study, we addressed this problem by introducing a new analysis approach. A planning computed tomography (CT) scan and 7 repeat cone-beam CT scans during the course of treatment were obtained for 19 prostate cancer patients who underwent three-dimensional conformal radiation therapy. A single observer contoured the prostate gland only. To evaluate the local deformation of the prostate, it was divided into 12 manually defined segments. Prostate deformation was calculated using in-house developed software. The correlation between the displacement of the CoG and the local deformation of the prostate was evaluated using multiple regression analysis. The mean value and standard deviation (SD) of the prostate deformation were 0.6 mm and 1.7 mm, respectively. For the majority of the patients, the local SD of the deformation was slightly lager in the superior and inferior segments. Multiple regression analysis revealed that the anterior-posterior displacement of the CoG of the prostate had a highly significant correlation with the deformations in the middle-anterior (p deformation of the prostate surface in other segments. Anterior-posterior displacement of the CoG of the prostate is highly correlated with deformation in its middle-anterior and posterior segments. In the radiation therapy for prostate cancer, it is necessary to optimize the internal margin for every position of the prostate measured using image-guided radiation therapy.

  4. The role of a prone setup in breast radiation therapy

    Directory of Open Access Journals (Sweden)

    Nelly eHuppert

    2011-10-01

    Full Text Available Most patients undergoing breast conservation therapy (BCT receive radiotherapy in the supine position. Historically, prone breast irradiation has been advocated for women with large pendulous breasts in order to decrease acute and late toxicities. With the advent of CT planning, the prone technique has become both feasible and reproducible. It was shown to be advantageous not only for women with larger breasts but in most patients since it consistently reduces, if not eliminates, the inclusion of heart and lung within the field. The prone setup has been accepted as the best localizing position for both MRI and stereotactic biopsy, but its adoption has been delayed in radiotherapy. New technological advances including image-modulated radiation therapy (IMRT and image-guided radiation therapy (IGRT have made possible the exploration of accelerated fractionation schemes with a concomitant boost to the tumor bed in the prone position, along with better imaging and verification of reproducibility of patient setup. This review describes some of the available techniques for prone breast radiotherapy and the available experience in their application. The NYU prone breast radiotherapy approach is discussed, including a summary of the results from several prospective trials.

  5. Prioritized efficiency optimization for intensity modulated proton therapy.

    Science.gov (United States)

    Müller, Birgit S; Wilkens, Jan J

    2016-12-07

    A high dosimetric quality and short treatment time are major goals in radiotherapy planning. Intensity modulated proton therapy (IMPT) plans obtain dose distributions of great conformity but often result in long delivery times which are typically not incorporated into the optimization process. We present an algorithm to optimize delivery efficiency of IMPT plans while maintaining plan quality, and study the potential trade-offs of these interdependent objectives. The algorithm is based on prioritized optimization, a stepwise approach to implemented objectives. First the quality of the plan is optimized. The second step of the prioritized efficiency optimization (PrEfOpt) routine offers four alternatives for reducing delivery time: minimization of the total spot weight sum (A), maximization of the lowest spot intensity of each energy layer (B), elimination of low-weighted spots (C) or energy layers (D). The trade-off between dosimetric quality (step I) and treatment time (step II) is controlled during the optimization by option-dependent parameters. PrEfOpt was applied to a clinical patient case, and plans for different trade-offs were calculated. Delivery times were simulated for two virtual facilities with constant and variable proton current, i.e. independent and dependent on the optimized spot weight distributions. Delivery times decreased without major degradation of plan quality; absolute time reductions varied with the applied method and facility type. Minimizing the total spot weight sum (A) reduced times by 28% for a similar plan quality at a constant current (changes of minimum dose in the target  optimization step into the optimization process can yield reduced delivery times with similar plan qualities. A potential clinical application of PrEfOpt is the generation of multiple plans with different trade-offs for a multicriteria optimization setting. Then, the planner can select the preferred compromise between treatment time and quality for each

  6. Implementation of Remote 3-Dimensional Image Guided Radiation Therapy Quality Assurance for Radiation Therapy Oncology Group Clinical Trials

    Energy Technology Data Exchange (ETDEWEB)

    Cui Yunfeng [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Galvin, James M. [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Radiation Therapy Oncology Group, American College of Radiology, Philadelphia, Pennsylvania (United States); Parker, William [Department of Medical Physics, McGill University Health Center, Montreal, QC (Canada); Breen, Stephen [Department of Radiation Physics, Princess Margaret Hospital, Toronto, ON (Canada); Yin Fangfang; Cai Jing [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Papiez, Lech S. [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Bednarz, Greg [Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Chen Wenzhou [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Xiao Ying, E-mail: ying.xiao@jefferson.edu [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Radiation Therapy Oncology Group, American College of Radiology, Philadelphia, Pennsylvania (United States)

    2013-01-01

    Purpose: To report the process and initial experience of remote credentialing of three-dimensional (3D) image guided radiation therapy (IGRT) as part of the quality assurance (QA) of submitted data for Radiation Therapy Oncology Group (RTOG) clinical trials; and to identify major issues resulting from this process and analyze the review results on patient positioning shifts. Methods and Materials: Image guided radiation therapy datasets including in-room positioning CT scans and daily shifts applied were submitted through the Image Guided Therapy QA Center from institutions for the IGRT credentialing process, as required by various RTOG trials. A centralized virtual environment is established at the RTOG Core Laboratory, containing analysis tools and database infrastructure for remote review by the Physics Principal Investigators of each protocol. The appropriateness of IGRT technique and volumetric image registration accuracy were evaluated. Registration accuracy was verified by repeat registration with a third-party registration software system. With the accumulated review results, registration differences between those obtained by the Physics Principal Investigators and from the institutions were analyzed for different imaging sites, shift directions, and imaging modalities. Results: The remote review process was successfully carried out for 87 3D cases (out of 137 total cases, including 2-dimensional and 3D) during 2010. Frequent errors in submitted IGRT data and challenges in the review of image registration for some special cases were identified. Workarounds for these issues were developed. The average differences of registration results between reviewers and institutions ranged between 2 mm and 3 mm. Large discrepancies in the superior-inferior direction were found for megavoltage CT cases, owing to low spatial resolution in this direction for most megavoltage CT cases. Conclusion: This first experience indicated that remote review for 3D IGRT as part of QA

  7. Intraoperative radiation therapy for breast cancer patients: current perspectives

    Directory of Open Access Journals (Sweden)

    Dutta SW

    2017-04-01

    Full Text Available Sunil W Dutta,1 Shayna L Showalter,2 Timothy N Showalter,1 Bruce Libby,1 Daniel M Trifiletti1 1Department of Radiation Oncology, 2Division of Surgical Oncology, Department of Surgery, University of Virginia School of Medicine, Charlottesville, VA, USA Abstract: Accelerated partial breast irradiation (APBI provides an attractive alternative to whole breast irradiation (WBI through normal tissue radiation exposure and reduced treatment duration. Intraoperative radiation therapy (IORT is a form of APBI with the shortest time interval, as it delivers the entirety of a planned radiation course at the time of breast surgery. However, faster is not always better, and IORT has been met with healthy skepticism. Patients treated with IORT have an increased compliance and overall satisfaction when compared to patients treated with WBI. However, early randomized trial results demonstrated an increased rate of recurrence after IORT, slowing its widespread adoption. Despite these controversies, IORT utilization is increasing nationally and several novel developments are aimed at continuing to minimize the risk of recurrence and treatment-related toxicity while maximizing the patient experience. Keywords: IORT, lumpectomy, breast conservation, electron, photon, evidence

  8. Has the use of computers in radiation therapy improved the accuracy in radiation dose delivery?

    Science.gov (United States)

    Van Dyk, J.; Battista, J.

    2014-03-01

    Purpose: It is well recognized that computer technology has had a major impact on the practice of radiation oncology. This paper addresses the question as to how these computer advances have specifically impacted the accuracy of radiation dose delivery to the patient. Methods: A review was undertaken of all the key steps in the radiation treatment process ranging from machine calibration to patient treatment verification and irradiation. Using a semi-quantitative scale, each stage in the process was analysed from the point of view of gains in treatment accuracy. Results: Our critical review indicated that computerization related to digital medical imaging (ranging from target volume localization, to treatment planning, to image-guided treatment) has had the most significant impact on the accuracy of radiation treatment. Conversely, the premature adoption of intensity-modulated radiation therapy has actually degraded the accuracy of dose delivery compared to 3-D conformal radiation therapy. While computational power has improved dose calibration accuracy through Monte Carlo simulations of dosimeter response parameters, the overall impact in terms of percent improvement is relatively small compared to the improvements accrued from 3-D/4-D imaging. Conclusions: As a result of computer applications, we are better able to see and track the internal anatomy of the patient before, during and after treatment. This has yielded the most significant enhancement to the knowledge of "in vivo" dose distributions in the patient. Furthermore, a much richer set of 3-D/4-D co-registered dose-image data is thus becoming available for retrospective analysis of radiobiological and clinical responses.

  9. Delineation of Supraclavicular Target Volumes in Breast Cancer Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Lindsay C. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Diehn, Felix E. [Department of Radiology, Mayo Clinic, Rochester, Minnesota (United States); Boughey, Judy C. [Department of Surgery, Mayo Clinic, Rochester, Minnesota (United States); Childs, Stephanie K.; Park, Sean S.; Yan, Elizabeth S.; Petersen, Ivy A. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Mutter, Robert W., E-mail: mutter.robert@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States)

    2015-07-01

    Purpose: To map the location of gross supraclavicular metastases in patients with breast cancer, in order to determine areas at highest risk of harboring subclinical disease. Methods and Materials: Patients with axial imaging of gross supraclavicular disease were identified from an institutional breast cancer registry. Locations of the metastatic lymph nodes were transferred onto representative axial computed tomography images of the supraclavicular region and compared with the Radiation Therapy Oncology Group (RTOG) breast cancer atlas for radiation therapy planning. Results: Sixty-two patients with 161 supraclavicular nodal metastases were eligible for study inclusion. At the time of diagnosis, 117 nodal metastases were present in 44 patients. Forty-four nodal metastases in 18 patients were detected at disease recurrence, 4 of whom had received prior radiation to the supraclavicular fossa. Of the 161 nodal metastases, 95 (59%) were within the RTOG consensus volume, 4 nodal metastases (2%) in 3 patients were marginally within the volume, and 62 nodal metastases (39%) in 30 patients were outside the volume. Supraclavicular disease outside the RTOG consensus volume was located in 3 regions: at the level of the cricoid and thyroid cartilage (superior to the RTOG volume), in the posterolateral supraclavicular fossa (posterolateral to the RTOG volume), and in the lateral low supraclavicular fossa (lateral to the RTOG volume). Only women with multiple supraclavicular metastases had nodal disease that extended superiorly to the level of the thyroid cartilage. Conclusions: For women with risk of harboring subclinical supraclavicular disease warranting the addition of supraclavicular radiation, coverage of the posterior triangle and the lateral low supraclavicular region should be considered. For women with known supraclavicular disease, extension of neck coverage superior to the cricoid cartilage may be warranted.

  10. Treatment of retinoblastoma by precision megavoltage radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Schipper, J.; Peperzeel, H.A. van (Rijksuniversiteit Utrecht (Netherlands). Academisch Ziekenhuis); Tan, K.E.W.P. (Royal Dutch Eye Hospital, Utrecht, Netherlands)

    1985-02-01

    The principal treatment concept in the Utrecht Retinoblastoma Centre is megavoltage irradiation, followed by light coagulation and/or cryotherapy if there is any doubt as to whether the residual tumour is still active. Radiation therapy is administered by means of a simple but highly accurate temporal beam technique. A standardized dose of 45 Gy is given in 15 fractions of 3 Gy at 3 fractions per week. From 1971 to 1982, 39 children with retinoblastoma have been irradiated in at least one eye. Of the 73 affected eyes, 18 were primarily enucleated, one received light coagulation only, and 54 received radiation therapy. Of the 54 irradiated eyes, 32 were additionally treated by light coagulation and/or cryotherapy for suspicious residual tumour (in 29 eyes), recurrent tumour (in 1 eye), and/or new tumour (in 3 eyes) and 10 were ultimately enucleated. Two eyes also received hyperthermia. The percentages of cure of the irradiated eyes with a minimum follow-up of 2 years were 100% (14/14), 100% (9/9), 83% (10/12), 79% (11/14) and 0% (0/5) in the Reese-Ellsworth groups I to V-A, respectively. Of the saved eyes 95% achieved useful vision. Eighteen eyes developed a clinically detectable radiation cataract; in five of these the lens was aspirated. Cataracts developed exclusively in those lenses of which a posterior portion of more than 1 mm had to be included in the treatment field. The likelihood and the degree of cataract formation was found to be directly related to the dose of radiation to the germinative zone of the lens epithelium. The minimum cataractogenic dose found in this series was 8 Gy.

  11. Solitary plasmacytomas: outcome and prognostic factors after definitive radiation therapy.

    Science.gov (United States)

    Reed, Valerie; Shah, Jatin; Medeiros, L Jeffery; Ha, Chul S; Mazloom, Ali; Weber, Donna M; Arzu, Isidora Y; Orlowski, Robert Z; Thomas, Sheeba K; Shihadeh, Ferial; Alexanian, Raymond; Dabaja, Bouthaina S

    2011-10-01

    The objective of this study was to review the outcome of patients with solitary plasmacytoma (SP) after definitive radiation therapy. The authors retrospectively reviewed 84 patients with SP who were diagnosed and treated at The University of Texas MD Anderson Cancer Center during 1988 to 2008. The impact of tumor anatomic site, tumor size, and the presence of serum and urinary paraprotein at diagnosis was assessed on local control, survival, and the risk of developing multiple myeloma (MM). Fifty-nine patients (70%) had bone SP, and 25 patients (30%) had extramedullary SP. Serum paraprotein was present in 39 patients (46%). The median radiation dose was 45 grays (Gy) (range, 36-53.4 Gy). Local control was achieved in 77 patients (92%). Neither radiation dose nor tumor size predicted local control. The 5-year rate of progression to MM was 47% and was higher for patients with bone SP (56% vs 30% for extramedullary SP; P = .021), and patients who had serum paraprotein detected at diagnosis (60% vs 39%; P = .016). On univariate analysis, patients aged location and serum protein at diagnosis were associated statistically with progression to MM. The 5-year overall survival rate for the entire patient cohort was 78%, and no difference was observed between patients who had bone SP versus extramedullary SP (76% vs 85%, respectively; P = .274). The current results indicated that definitive radiation therapy for SP can provide excellent local control. Progression to MM remains the main problem and is more common among patients with bone SP and those who have serum paraprotein detected at diagnosis. Copyright © 2011 American Cancer Society.

  12. Hyperfractionation radiation therapy in advanced head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hee; Ye, Ji Won [College of Medicine, Keimyung Univ., Daegu (Korea, Republic of)

    2003-03-01

    The effects of hyperfractionation radiation therapy, such as the failure pattern and survival, on the treatment results in advanced stage head and neck cancer were studied. Between September 1990 and October 1998, 24 patients with advanced stage (III, IV) head and neck cancers, were treated using hyperfractionation radiation therapy in the Department at Radiation Oncology at the Keimyung University Dongsan Medical Center. The male to female ratio was 7 ; 1, and the age range from 38 to 71 years with the median of 56 years. With regard to the TNM stage, 11 patients were stage III and 13 were stage IV. The sites of primary cancer were the nasopharynx in six, the hypopharynx in 6, the larynx in five, the oropharynx in three, the maxillary sinus in three, and the oral cavity in one patient. The radiotherapy was delivered by 6 MV X-ray, with a fraction size of 1.2 Gy at two fractions a day, with at least 6 hours inter-fractional interval. The mean total radiation doses was 72 Gy, (ranging from 64.4 to 76.8 Gy). Fallow-up periods ranged between 3 and 136 months, with the median of 52 months. The overall survival rates at 3 and 5 years in all patients were 66.7% and 52.4%. The disease-free survival rates at 3 and 5 years (3YDFS, 5YDFS) in all patients Were 66.7% and 47.6%. The 3YDFS and 5YDFS in stage III patients were 81.8% and 63.6%, and those in stage IV patients were 53.8% and 32.3%. Ten patients were alive with no local nor distant failures at the time of analyses. Six patients (25%) died due to distant metastasis and 12.5% died due to local failure. Distant metastasis was the major cause of failure, but 2 patients died due to unknown failures and 3 of other diseases. The distant metastasis sites were the lung (3 patients), the bone (1 patient), and the liver (2 patients). One patient died of second esophageal cancer. There were no severe late complications, with the exception of 1 osteoradionecrosis of the mandible 58 months after treatment. Although this study was

  13. Extrapleural pneumonectomy, photodynamic therapy and intensity modulated radiation therapy for the treatment of malignant pleural mesothelioma.

    Science.gov (United States)

    Du, Kevin L; Both, Stefan; Friedberg, Joseph S; Rengan, Ramesh; Hahn, Stephen M; Cengel, Keith A

    2010-09-01

    Intensity modulated radiation therapy (IMRT) has recently been proposed for the treatment of malignant pleural mesothelioma (MPM). Here, we describe our experience with a multimodality approach for the treatment of mesothelioma, incorporating extrapleural pneumonectomy, intraoperative photodynamic therapy and postoperative hemithoracic IMRT. From 2004-2007, we treated 11 MPM patients with hemithoracic IMRT, 7 of whom had undergone porfimer sodium-mediated PDT as an intraoperative adjuvant to surgical debulking. The median radiation dose to the planning treatment volume (PTV) ranged from 45.4-54.5 Gy. For the contralateral lung, V20 ranged from 1.4-28.5%, V5 from 42-100% and MLD from 6.8-16.5 Gy. In our series, 1 patient experienced respiratory failure secondary to radiation pneumonitis that did not require mechanical ventilation. Multimodality therapy combining surgery with increased doses of radiation using IMRT, and newer treatment modalities such as PDT , appears safe. Future prospective analysis will be needed to demonstrate efficacy of this approach in the treatment of malignant mesothelioma. Efforts to reduce lung toxicity and improve dose delivery are needed and provide the promise of improved local control and quality of life in a carefully chosen multidisciplinary approach.

  14. Linear algebraic methods applied to intensity modulated radiation therapy.

    Science.gov (United States)

    Crooks, S M; Xing, L

    2001-10-01

    Methods of linear algebra are applied to the choice of beam weights for intensity modulated radiation therapy (IMRT). It is shown that the physical interpretation of the beam weights, target homogeneity and ratios of deposited energy can be given in terms of matrix equations and quadratic forms. The methodology of fitting using linear algebra as applied to IMRT is examined. Results are compared with IMRT plans that had been prepared using a commercially available IMRT treatment planning system and previously delivered to cancer patients.

  15. 3D measurement of absolute radiation dose in grid therapy

    Science.gov (United States)

    Trapp, J. V.; Warrington, A. P.; Partridge, M.; Philps, A.; Leach, M. O.; Webb, S.

    2004-01-01

    Spatially fractionated radiotherapy through a grid is a concept which has a long history and was routinely used in orthovoltage radiation therapy in the middle of last century to minimize damage to the skin and subcutaneous tissue. With the advent of megavoltage radiotherapy and its skin sparing effects the use of grids in radiotherapy declined in the 1970s. However there has recently been a revival of the technique for use in palliative treatments with a single fraction of 10 to 20 Gy. In this work the absolute 3D dose distribution in a grid irradiation is measured for photons using a combination of film and gel dosimetry.

  16. Image-guided radiation therapy. Paradigm change in radiation therapy; Bildgestuetzte Strahlentherapie. Paradigmenwechsel in der Strahlentherapie

    Energy Technology Data Exchange (ETDEWEB)

    Wenz, F. [Universitaetsmedizin Mannheim der Universitaet Heidelberg, Klinik fuer Strahlentherapie und Radioonkologie, Mannheim (Germany); Belka, C. [Klinikum der Ludwig-Maximilians-Universitaet, Klinik fuer Strahlentherapie und Radioonkologie, Muenchen (Germany); Reiser, M. [Klinikum der Ludwig-Maximilians-Universitaet, Institut fuer Klinische Radiologie, Muenchen (Germany); Schoenberg, S.O. [Universitaetsmedizin Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Mannheim (Germany)

    2012-03-15

    The introduction of image-guided radiotherapy (IGRT) has changed the workflow in radiation oncology more dramatically than any other innovation in the last decades. Imaging for treatment planning before the initiation of the radiotherapy series does not take alterations in patient anatomy and organ movement into account. The principle of IGRT is the temporal and spatial connection of imaging in the treatment position immediately before radiation treatment. The actual position and the target position are compared using cone-beam computed tomography (CT) or stereotactic ultrasound. The IGRT procedure allows a reduction of the safety margins and dose to normal tissue without an increase in risk of local recurrence. In the future the linear treatment chain in radiation oncology will be developed based on the closed-loop feedback principle. The IGRT procedure is increasingly being used especially for high precision radiotherapy, e.g. for prostate or brain tumors. (orig.) [German] Die Einfuehrung der bildgestuetzten Radiotherapie (IGRT - ''image-guided radiotherapy'') hat wie kaum eine andere Innovation die Behandlungsablaeufe in der Radioonkologie veraendert. Eine einmalige Bildgebung zur Bestrahlungsplanung vor der Behandlungsserie beruecksichtigt nicht die Aenderung der Patientengeometrie und die Organbeweglichkeit. Das Prinzip der IGRT besteht in der raeumlichen und zeitlichen Zusammenfuehrung von Bildgebung in der Bestrahlungsposition unmittelbar vor der eigentlichen Bestrahlung. Mittels Cone-beam-CT oder stereotaktischem Ultraschall wird die Ist- mit der Sollposition verglichen. Die IGRT erlaubt die Reduktion der Sicherheitssaeume und damit die Schonung des Normalgewebes, ohne das Rezidivrisiko zu erhoehen. Zukuenftig wird die lineare Behandlungskette in der Radioonkologie durch eine geschlossene, multipel rueckgekoppelte Therapieschleife ersetzt werden. Speziell bei Praezisionsbestrahlungen wie z. B. Prostata- oder Hirntumoren kommt die IGRT

  17. 21 CFR 892.5770 - Powered radiation therapy patient support assembly.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered radiation therapy patient support assembly. 892.5770 Section 892.5770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... therapy patient support assembly. (a) Identification. A powered radiation therapy patient support assembly...

  18. Therapy of patients with osteoarthritis with low energy laser radiation

    Directory of Open Access Journals (Sweden)

    L. V. Vasiljeva

    2008-01-01

    Full Text Available Objective. To assess influence oflow energy laser radiation (LELR on glycosaminoglycan (GAG and vitamin С level in pts with osteoarthritis (OA. Material and methods. 82 pts with primary OA and 25 healthy volunteers signed informed consent were included in an open randomized prospective 12-month study. Inclusion criteria: unsatisfactory effect of previous drug therapy (DT, stable NSAID dose 3-5 days before and during LELR course, absence of comorbid hepatic and kidney diseases in stage of functional decompensation, malignant diseases, exclusion therapy influencing microcirculation, exercise therapy, physical therapy. Intra-articular injections were not done during 3 months before the study. Pts were divided into 2 groups. Group 1 received complex DT and LELR, group 2 - DT. clinical and laboratory parameters were used as efficacy measures. Statistical analysis was performed on personal computer IBM PC (OS — Windows EP Home Edition with Microsoft office and STATISTICA 6.0 programs. Results. Analysis of the results showed significant improvement of most measures in comparison with traditional DT. LELR administration allowed to decrease chondroprotector and NSAID doses. Vitamin С decrease in serum of OA pts may be a risk factor of development and progression of this disease.

  19. Sequential estrogen and radiation therapy for stage C prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tachibana, Yuichi; Kawai, Tsuneo; Kobayashi, Tsuyoshi; Yamauchi, Tamio; Aizawa, Taku (Japanese Foundation for Cancer Research, Tokyo (Japan). Hospital)

    1993-03-01

    Twenty of 34 stage C cases have been treated by sequential estrogen and radiation in our hospital between 1980 and 1989 and half of them had actually been done staging operation. An average age was 69.3. Tumor differentiations were distributed well in 5 cases, moderately in 5 and poorly in 9. The other unknown differentiation case was diagnosed by fine needle aspiration cytology. Previously administered estrogens were diethylstilbestrol diphosphate in 15 cases and others in 5. Total doses of 70 Gy in 35 fractions were sequentially delivered to the prostate, involving if necessary the seminal vesicles over a seven-week period by bilateral 120deg pendel using linear accelerator. Radiation field was sized from 6 x 6 to 8 x 8 cm. Estrogens have been continuously administered following radiation in 11 cases. Therapeutic effects upon the prostate were evaluated by digital rectal palpation. Improvement rate and atrophy rate of the primary lesion were 94.4% and 50% respectively. Recurrences were observed in 4 cases and 3 of them recurred within 3 years after initiation of the treatment. Recurred sites were in primary lesion in 2 cases and in bone in two. Five year non-recurrence rate was 81% by Kaplan Meier's method. One of 3 who discontinued hormone administration during or immediately after radiotherapy had local recurrence after 65 months and the other 2 cases died of gastric cancer and unknown cause. Causes of 6 dead cases were one prostate cancer, one gastric cancer, one heart failure, one pneumonia and 2 unknown. The cancer death rate was 25% (1/4 cases). Five year cumulative survival rate by Kaplan-Meier's method was 59.0%. Our results support the view that the sequential estrogen and radiation therapy for the pathological stage C patients of the prostate cancer may be as preferable as radiation alone for the treatment of stage B prostate cancer. (J.P.N.).

  20. Some strategies of activation therapy using radiations of microwave ranges in experiments on tumorbearing animals

    Directory of Open Access Journals (Sweden)

    Galina V. Zhukova

    2015-11-01

    Full Text Available The paper offers an analysis of activation therapy approaches to an increase in efficacy of antitumor treatment with the use of electromagnetic-nature factors as developed by L.Kh. Garkavi and E.B.Kvakina. Basic principles of optimization of the effects of exposures to electromagnetic radiation in various frequency bands, considering the patterns of development of general unspecific adaptation reactions of the organism as well as conceptual presentation of the organism as a complex nonlinear dissipative system, are described herein. Analyzed are effects of exposure to low-intensity radiationin the millimeter and decimeter wave bands, undertaken according to the above principles, detected in oculated tumor bearing rats. A weak infra-low magnetic field was applied in the study as an additional factor. The experimental study shows a possibility to obtain marked antitumor effects without use of conventional antitumor therapy means.

  1. Heuristic optimization of the scanning path of particle therapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, J.; Donetti, M.; Bourhaleb, F.; Ansarinejad, A.; Attili, A.; Cirio, R.; Garella, M. A.; Giordanengo, S.; Givehchi, N.; La Rosa, A.; Marchetto, F.; Monaco, V.; Pecka, A.; Peroni, C.; Russo, G.; Sacchi, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy) and Fondazione CNAO, Via Caminadella 16, I-20123, Milano (Italy); Dipartimento di Fisica Sperimentale, Universita di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy) and Dipartimento di Fisica Sperimentale, Universita di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy) and Dipartimento di Fisica Sperimentale, Universita di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy) and Dipartimento di Fisica Sperimentale, Universita di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy) and Dipartimento di Fisica Sperimentale, Universita di Torino, Via P. Giuria 1, I-10125 Torino (Italy)

    2009-06-15

    Quasidiscrete scanning is a delivery strategy for proton and ion beam therapy in which the beam is turned off when a slice is finished and a new energy must be set but not during the scanning between consecutive spots. Different scanning paths lead to different dose distributions due to the contribution of the unintended transit dose between spots. In this work an algorithm to optimize the scanning path for quasidiscrete scanned beams is presented. The classical simulated annealing algorithm is used. It is a heuristic algorithm frequently used in combinatorial optimization problems, which allows us to obtain nearly optimal solutions in acceptable running times. A study focused on the best choice of operational parameters on which the algorithm performance depends is presented. The convergence properties of the algorithm have been further improved by using the next-neighbor algorithm to generate the starting paths. Scanning paths for two clinical treatments have been optimized. The optimized paths are found to be shorter than the back-and-forth, top-to-bottom (zigzag) paths generally provided by the treatment planning systems. The gamma method has been applied to quantify the improvement achieved on the dose distribution. Results show a reduction of the transit dose when the optimized paths are used. The benefit is clear especially when the fluence per spot is low, as in the case of repainting. The minimization of the transit dose can potentially allow the use of higher beam intensities, thus decreasing the treatment time. The algorithm implemented for this work can optimize efficiently the scanning path of quasidiscrete scanned particle beams. Optimized scanning paths decrease the transit dose and lead to better dose distributions.

  2. Current status of radiation therapy. Evidence-based medicine (EBM) of radiation therapy. Radiotherapy for pharyngeal and laryngeal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chatani, Masashi [Osaka Rosai Hospital, Sakai (Japan)

    2002-03-01

    Radiation therapy is the first choice of treatment for early pharyngeal and laryngeal cancers, especially those of the glotic larynx and nasopharynx. For advanced lesions without distant metastasis, more intensive treatments, i.e., chemoradiotherapy, multiple fractions per day, and conformal radiotherapy are introduced to improve local control and survival. However, the level of evidence-based medicine is different for each treatment modality. In this review, recent reports of radiotherapy for pharyngeal and laryngeal cancer are introduced from the point of view of the evidence level. (author)

  3. Adjuvant radiation therapy in metastatic lymph nodes from melanoma

    Directory of Open Access Journals (Sweden)

    Penel Nicolas

    2011-02-01

    Full Text Available Abstract Purpose To analyze the outcome after adjuvant radiation therapy with standard fractionation regimen in metastatic lymph nodes (LN from cutaneous melanoma. Patients and methods 86 successive patients (57 men were treated for locally advanced melanoma in our institution. 60 patients (69% underwent LN dissection followed by radiation therapy (RT, while 26 patients (31% had no radiotherapy. Results The median number of resected LN was 12 (1 to 36 with 2 metastases (1 to 28. Median survival after the first relapse was 31.8 months. Extracapsular extension was a significant prognostic factor for regional control (p = 0.019. Median total dose was 50 Gy (30 to 70 Gy. A standard fractionation regimen was used (2 Gy/fraction. Median number of fractions was 25 (10 to 44 fractions. Patients were treated with five fractions/week. Patients with extracapsular extension treated with surgery followed by RT (total dose ≥50 Gy had a better regional control than patients treated by surgery followed by RT with a total dose Conclusion Adjuvant radiotherapy was able to increase regional control in targeted sub-population (LN with extracapsular extension.

  4. Subacute brain atrophy after radiation therapy for malignant brain tumor

    Energy Technology Data Exchange (ETDEWEB)

    Asai, A.; Matsutani, M.; Kohno, T.; Nakamura, O.; Tanaka, H.; Fujimaki, T.; Funada, N.; Matsuda, T.; Nagata, K.; Takakura, K.

    1989-05-15

    Brain atrophy with mental and neurologic deterioration developing a few months after radiation therapy in patients without residual or recurrent brain tumors has been recognized. Two illustrative case reports of this pathologic entity are presented. Six autopsy cases with this entity including the two cases were reviewed neurologically, radiographically, and histopathologically. All patients presented progressive disturbances of mental status and consciousness, akinesia, and tremor-like involuntary movement. Computerized tomography (CT) demonstrated marked enlargement of the ventricles, moderate widening of the cortical sulci, and a moderately attenuated CT number for the white matter in all six patients. Four of the six patients had CSF drainage (ventriculoperitoneal shunt or continuous lumbar drainage), however, none of them improved. Histologic examination demonstrated swelling and loss of the myelin sheath in the white matter in all patients, and reactive astrocytosis in three of the six patients. Neither prominent neuronal loss in the cerebral cortex or basal ganglia, nor axonal loss in the white matter was generally identified. The blood vessels of the cerebral cortex and white matter were normal. Ependymal layer and the surrounding brain tissue were normal in all patients. These findings suggested that this pathologic condition results from demyelination secondary to direct neurotoxic effect of irradiation. The authors' previous report was reviewed and the differential diagnoses, the risk factors for this pathologic entity, and the indication for radiation therapy in aged patients with a malignant brain tumor are discussed.

  5. Sexual function after surgical and radiation therapy for cervical carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Seibel, M. (Beth Israel Hospital, Boston, MA); Freeman, M.G.; Graves, W.L.

    1982-10-01

    One hundred women treated for carcinoma of the cervix were interviewed more than one year later to establish the effects of radiation or surgical therapy on sexual function. Forty-three had received irradiation, 44 nonradical surgery, six combined surgery and irradiation, and seven radical surgery. The irradiation and nonradical surgery groups were each further subdivided into subgroups of patients aged 30 to 49 for age-controlled comparison. Patients in the irradiation group had statistically significant decreases in sexual enjoyment, ability to attain orgasm, coital opportunity, frequency of intercourse, and coital desire. The group who had nonradical surgical procedures had no significant change in sexual function after treatment. Similar results were found in both age-controlled subgroups, eliminating age as a major etiologic factor. Marked vaginal alterations were recorded in the majority of irradiated patients, but were not present among the groups treated with nonradical surgery. The vaginal changes alone could not be held accountable for the significant decrease in sexual function among women who received pelvic irradiation. The origin of decreased sexual desire after radiation therapy is complex, and not yet completely understood. We propose therapeutic programs to help women deal with the emotional and physical consequences of pelvic irradiation.

  6. Late Effects of Radiation Therapy in Pediatric Cancer Survivors.

    Science.gov (United States)

    Arain, Abeer; Herman, Terence; Matthiesen, Chance

    2015-04-01

    The overall survival rates of many pediatric cancers continue to improve with each decade due to new advances in therapy. As this trend continues, the focus and importance of minimizing acute and long-term toxicity associated with treatment is paramount. While significant research regarding many of the late responses of normal tissues associated with radiation exposure has been established, future endeavors must be directed toward the identification of therapy related factors including radiation total dose, dose rate, exposure, and target treatment volumes. Awareness of short and long-term health risks of these patients is important and careful follow-up of long-term survivors is essential. In this report, we review some selected late adverse effects including the development of secondary malignancies, cardiotoxicity, physiological changes to glandular tissue, hormonal and reproductive changes to germ cells, and neurocognitive changes. Furthermore, we compared the differences regarding late effects of normal tissues associated with the use of proton versus photon radiotherapy, a topic that has received a great deal of attention in pediatric cancer and is increasing in utilization in the United States and world-wide.

  7. Ion chambers compliance results of Brazilian radiation therapy facilities.

    Science.gov (United States)

    Joana, Georgia Santos; Salata, Camila; Leal, Paulo; Oliveira, Renato; Couto, Nozimar do; Teixeira, Flavia Cristina; Soares, Abner Duarte; Santini, Eduardo Sergio; Gonçalves, Marcello Gomes

    2017-12-07

    Brazilian Nuclear Energy Commission (cnen) has been making a constant effort to keep updated with international standards and national needs to strengthen the status of radiological protection of the country. The guidelines related to radiation therapy facilities have been revised in the last five years in order to take in consideration the most relevant aspects of the growing technology as well as to mitigate the accidents or incidents observed in practice. Hence, clinical dosimeters have gained special importance in this matter. In the present work we discuss the effectiveness of regulation and inspections to the enforcement of instrument calibration accuracy for improvement of patient dosimetry and quality control. As a result, we observed that the number of calibrated instruments, mainly well-chambers, is increasing each year. The same behavior is observed for instruments employed in technologically advanced radiation treatments such as intensity modulated radiotherapy (imrt), volumetric therapy and stereotatic radiosurgery (srs). We ascribe this behavior to the new regulation. © 2017 IOP Publishing Ltd.

  8. Surgical procedures for digestive fistulae caused by radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Satoshi; Honda, Ichiro; Watanabe, Kazuo; Nagata, Matsuo; Yamamoto, Hiroshi; Soda, Hiroaki; Tasaki, Kentaro [Chiba Cancer Center Hospital (Japan)

    2002-09-01

    We evaluated the effectiveness of surgery to treat ileal fistulations associated with radiation exposure. An ileal fistula developed in eight patients, 13-102 months after 60 Gy of irradiation to the pelvic cavity, given as initial treatment or supportive therapy following resection of the primary tumor. The underlying diseases were cervical cancer in seven women and bladder cancer in one man. Two patients had an ileorectal fistula, two had an ileosigmoidal fistula, three had an ileovesical fistula, and one had an ileourethral fistula. We performed a partial enterectomy in one patient, a simple bypass operation without exclusion in one, and bypass operations with exclusion in the other six. Intestinal expansion in the exclusion site occurred in one patient, but there were no other complications related directly to surgery, such as sutural insufficiency. The patient who underwent a simple bypass operation died of emaciation 2 months after the surgery, but all of the other patients were discharged capable of oral ingestion. Our findings showed that surgery was beneficial for alleviating the various conditions related to digestive fistulation following radiation therapy. (author)

  9. Enhanced Radiation Therapy of Gold Nanoparticles in Liver Cancer

    Directory of Open Access Journals (Sweden)

    Meili Guo

    2017-03-01

    Full Text Available Gold nanoparticles (GNPs were widely used in X-ray imaging and radiation therapy due to strong photoelectric effects and secondary electrons under high energy irradiation. As liver cancer is one of the most common forms of cancer, the use of GNPs could enhance liver cancer radiotherapy. We synthesized polyethylene glycol (PEG-coated GNPs of two different sizes by chemical reduction reaction. Blood stability, cellular uptake, cytotoxicity and radiation therapy were investigated. A 3–5 nm red shift of SPR caused by interactions between PEG-coated GNPs and plasma indicated their good stability. Cellular uptake assay showed that PEG-coated GNPs would enhance an appreciable uptake. GNPs preferred to combine with blood proteins, and thus induced the formation of 30–50 nm Au-protein corona. GNPs were endocytosed by cytoplasmic vesicles, localized in intracellular region, and presented concentration dependent cell viability. Clonogenic assay illustrated that the PEG-coated GNPs could sensitize two liver cancer cell lines to irradiation.

  10. MO-G-9A-01: Imaging Refresher for Standard of Care Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Labby, Z [The University of Michigan Hospital ' Health Sys, Ann Arbor, MI (United States); Sensakovic, W [Florida Hospital, Orlando, FL (United States); Hipp, E [NYULMC Clinical Cancer Center, New York, NY (United States); Altman, M [Washington University School of Medicine, St. Louis, MO (United States)

    2014-06-15

    Imaging techniques and technology which were previously the domain of diagnostic medicine are becoming increasingly integrated and utilized in radiation therapy (RT) clinical practice. As such, there are a number of specific imaging topics that are highly applicable to modern radiation therapy physics. As imaging becomes more widely integrated into standard clinical radiation oncology practice, the impetus is on RT physicists to be informed and up-to-date on those imaging modalities relevant to the design and delivery of therapeutic radiation treatments. For example, knowing that, for a given situation, a fluid attenuated inversion recovery (FLAIR) image set is most likely what the physician would like to import and contour is helpful, but may not be sufficient to providing the best quality of care. Understanding the physics of how that pulse sequence works and why it is used could help assess its utility and determine if it is the optimal sequence for aiding in that specific clinical situation. It is thus important that clinical medical physicists be able to understand and explain the physics behind the imaging techniques used in all aspects of clinical radiation oncology practice. This session will provide the basic physics for a variety of imaging modalities for applications that are highly relevant to radiation oncology practice: computed tomography (CT) (including kV, MV, cone beam CT [CBCT], and 4DCT), positron emission tomography (PET)/CT, magnetic resonance imaging (MRI), and imaging specific to brachytherapy (including ultrasound and some brachytherapy specific topics in MR). For each unique modality, the image formation process will be reviewed, trade-offs between image quality and other factors (e.g. imaging time or radiation dose) will be clarified, and typically used cases for each modality will be introduced. The current and near-future uses of these modalities and techniques in radiation oncology clinical practice will also be discussed. Learning

  11. Long-Term Outcome After Radiotherapy in Patients With Atypical and Malignant Meningiomas-Clinical Results in 85 Patients Treated in a Single Institution Leading to Optimized Guidelines for Early Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Adeberg, Sebastian [Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg (Germany); Hartmann, Christian [Department of Neuropathology, Institute for Pathology, University Hospital of Heidelberg, Heidelberg (Germany); German Cancer Research Center, Clinical Cooperation Unit Neuropathology, Heidelberg (Germany); Welzel, Thomas; Rieken, Stefan; Habermehl, Daniel [Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg (Germany); Deimling, Andreas von [Department of Neuropathology, Institute for Pathology, University Hospital of Heidelberg, Heidelberg (Germany); German Cancer Research Center, Clinical Cooperation Unit Neuropathology, Heidelberg (Germany); Debus, Juergen [Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg (Germany); Combs, Stephanie E., E-mail: Stephanie.combs@med.uni-heidelberg.de [Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg (Germany)

    2012-07-01

    Purpose: Previously, we could show that the new World Health Organization (WHO) classification of meningiomas significantly correlated with outcome in patients with atypical and anaplastic histology. In the present work, we analyzed our long-term experience in radiotherapy for atypical and malignant meningioma diagnosed according to the most recent WHO categorization system. Patients and Methods: Sixty-two patients with atypical and 23 patients with malignant meningioma have been treated with radiotherapy. Sixty percent of all patients received radiotherapy (RT) after surgical resection, 19% at disease progression and 8.3% as a primary treatment. Radiation was applied using different techniques including fractionated stereotactic RT (FSRT), intensity-modulated RT, and combination treatment with carbon ions. The median PTV was 156.0 mL. An average dose of 57.6 Gy (range, 30-68.4 Gy) in 1.8-3 Gy fractions was applied. All patients were followed regularly including clinical-neurological follow-up as well as computed tomographies or magnetic resonance imaging. Results: Overall survival was impacted significantly by histological grade, with 81% and 53% at 5 years for atypical or anaplastic meningiomas, respectively. This difference was significant at p = 0.022. Eighteen patients died of tumor progression during follow-up. Progression-free survival was 95% and 50% for atypical, and 63% and 13% for anaplastic histology at 2 and 5 years. This difference was significant at p = 0.017. Despite histology, we could not observe any prognostic factors including age, resection status, or Karnofsky performance score. However, preexisting clinical symptoms observed in 63 patients improved in 29.3% of these patients. Conclusion: RT resulted in improvement of preexisting clinical symptoms; outcome is comparable to other series reported in the literature. RT should be offered after surgical resection after initial diagnosis to increase progression-free survival as well as overall

  12. Gaps in Radiation Therapy Awareness: Results From an Educational Multi-institutional Survey of US Internal Medicine Residents.

    Science.gov (United States)

    Shaverdian, Narek; Yoo, Sun Mi; Cook, Ryan; Chang, Eric M; Jiang, Naomi; Yuan, Ye; Sandler, Kiri; Steinberg, Michael; Lee, Percy

    2017-08-01

    Internists and primary care providers play a growing role in cancer care. We therefore evaluated the awareness of radiation therapy in general and specifically the clinical utility of stereotactic body radiation therapy (SBRT) for early-stage non-small cell lung cancer (NSCLC) among current US internal medicine residents. A web-based institutional review board-approved multi-institutional survey was distributed to US internal medicine residency programs. The survey evaluated trainee demographic characteristics, baseline radiation oncology awareness, knowledge of the role of SBRT for early-stage NSCLC, and whether the survey successfully improved awareness. Thirty US internal medicine programs participated, with an overall participant response rate of 46% (1177 of 2551). Of the trainees, 93% (n=1076) reported no radiation oncology education in their residency, 39% (n=452) reported confidence in knowing when to consult radiation oncology in an oncologic emergency, and 26% (n=293) reported confidence in knowing when to consult radiation oncology in the setting of a newly diagnosed cancer. Of the participants, 76% (n=850) correctly identified that surgical resection is the standard treatment in operable early-stage NSCLC, but only 50% (n=559) of participants would recommend SBRT to a medically inoperable patient, followed by 31% of participants (n=347) who were unsure of the most appropriate treatment, and 10% (n=117) who recommended waiting to offer palliative therapy. Ninety percent of participants (n=1029) agreed that they would benefit from further training on when to consult radiation oncology. Overall, 96% (n=1072) indicated that the survey increased their knowledge and awareness of the role of SBRT. The majority of participating trainees received no education in radiation oncology in their residency, reported a lack of confidence regarding when to consult radiation oncology, and overwhelmingly agreed that they would benefit from further training. These findings

  13. Usefulness of radiation treatment planning allpied respiration factor for streotatic body radiation therapy in the lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sung Pil; Kim, Tae Hyung; So, Woon Young; Back, Geum Mun [Dept. of Medical Health Science, Graduate School, Kangwon National University, Chuncheon (Korea, Republic of)

    2016-12-15

    We are evaluated the usefulness of radiation treatment planning applied respiration factor for stereotactic body radiation therapy in the lung cancer. Four dimensional computed tomography images were obtained in 10 patients with lung cancer. The radiation treatment plans were established total lung volume according to respiration images (new method) and conventional method. We was analyzed in the lung volume, radiation absorbed dose of lung and main organs (ribs, tracheobronchus, esophagus, spinal cord) around the tumor, respectively. We were confirmed that lung volume and radiation absorbed dose of lung and main organs around the tumor deference according to applied respiration. In conclusion, radiation treatment planning applied respiration factor seems to be useful for stereotactic body radiation therapy in the lung cancer.

  14. SU-E-P-07: Evaluation of Productivity Systems for Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, C; Usynin, A [Thompson Cancer Survival Center, Knoxville, TN (United States)

    2014-06-01

    Purpose: Health systems throughout the United States are under increased financial pressure to reduce operating cost. As a result, productivity models developed by third-party consultants are being used to optimize staff to treatment volumes. The purpose of this study was to critically evaluate productivity systems for radiation oncology. Methods: Staffing efficiency was evaluated using multiple productivity models. The first model evaluated staffing levels using equal weighting of procedure codes and hours worked. A second productivity model was developed using hours worked by job class and relative value units for each procedure code. A third model was developed using the measured procedure times extracted from the electronic medical record, which tracks the wait and treatment times for each patient for each treatment fraction. A MatLab program was developed to query and analyze the daily treatment data. A model was then created to determine any theoretical gains in treatment productivity. Results: Productivity was evaluated for six radiation therapy departments operating nine linear accelerators delivering over 40,000 treatment fractions per year. Third party productivity models that do not take into consideration the unique nature of radiation therapy can be counterproductive. For example, other outpatient departments can compress their daily schedule to decrease the worked hours. This approach was tested using the treatment schedule evaluation tool developed as part of this study. It was determined that the maximum possible savings for treatment schedule compression was $32,000 per year per linac. All annual cost savings would be lost if only two patients per year choose to be treated elsewhere because of limited or restricted appointment times. Conclusion: The use of productivity models in radiation therapy can easily result in a loss of treatment revenue that is greater than any potential cost savings in reduced hours worked by staff.

  15. Ultrasound Thermometry for Therapy-level Radiation Dosimetry

    Science.gov (United States)

    Taylor, Courtney

    2010-03-01

    Radiation oncology is the process of administering a specified dose of radiation to a patient currently receiving treatment for a form of cancer. In this process, it is vital to know the delivered dose for a given radiation beam to correctly treat a patient. The primary reference standard for absorbed dose is established using water calorimetry. The absorbed dose, typically of order 1 Gy (J/kg) at therapy levels, is realized by measuring sub-millikelvin temperature changes using a thermistor in a sensitive Wheatstone bridge. Ultrasound technology has been investigated as an alternative to thermistor measurements since the speed of sound propagation in water varies with temperature. With ultrasonic time-of-flight and highly sensitive phase detection techniques, temperature sensitivity comparable to that of the thermistor bridge has been achieved without introducing non-water materials into the test area. A single ultrasound transducer transmitting and receiving at 5.0 MHz throughout the length of the water phantom, and the phase change of the sound wave was used to determine temperature increase from an irradiative source at specified depths of the phantom. In this experiment, the exposure period was varied from 15s to 160s cyclically by modulating a heat lamp, and a profile of the measured temperature response as a function of the period was obtained using Fourier analysis. Due to the large temperature gradient in the water phantom, measurements are prone to convection which was indeed observed and will be discussed.

  16. Therapeutic Implications for Overcoming Radiation Resistance in Cancer Therapy

    Science.gov (United States)

    Kim, Byeong Mo; Hong, Yunkyung; Lee, Seunghoon; Liu, Pengda; Lim, Ji Hong; Lee, Yong Heon; Lee, Tae Ho; Chang, Kyu Tae; Hong, Yonggeun

    2015-01-01

    Ionizing radiation (IR), such as X-rays and gamma (γ)-rays, mediates various forms of cancer cell death such as apoptosis, necrosis, autophagy, mitotic catastrophe, and senescence. Among them, apoptosis and mitotic catastrophe are the main mechanisms of IR action. DNA damage and genomic instability contribute to IR-induced cancer cell death. Although IR therapy may be curative in a number of cancer types, the resistance of cancer cells to radiation remains a major therapeutic problem. In this review, we describe the morphological and molecular aspects of various IR-induced types of cell death. We also discuss cytogenetic variations representative of IR-induced DNA damage and genomic instability. Most importantly, we focus on several pathways and their associated marker proteins responsible for cancer resistance and its therapeutic implications in terms of cancer cell death of various types and characteristics. Finally, we propose radiation-sensitization strategies, such as the modification of fractionation, inflammation, and hypoxia and the combined treatment, that can counteract the resistance of tumors to IR. PMID:26569225

  17. Therapeutic Implications for Overcoming Radiation Resistance in Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Byeong Mo Kim

    2015-11-01

    Full Text Available Ionizing radiation (IR, such as X-rays and gamma (γ-rays, mediates various forms of cancer cell death such as apoptosis, necrosis, autophagy, mitotic catastrophe, and senescence. Among them, apoptosis and mitotic catastrophe are the main mechanisms of IR action. DNA damage and genomic instability contribute to IR-induced cancer cell death. Although IR therapy may be curative in a number of cancer types, the resistance of cancer cells to radiation remains a major therapeutic problem. In this review, we describe the morphological and molecular aspects of various IR-induced types of cell death. We also discuss cytogenetic variations representative of IR-induced DNA damage and genomic instability. Most importantly, we focus on several pathways and their associated marker proteins responsible for cancer resistance and its therapeutic implications in terms of cancer cell death of various types and characteristics. Finally, we propose radiation-sensitization strategies, such as the modification of fractionation, inflammation, and hypoxia and the combined treatment, that can counteract the resistance of tumors to IR.

  18. A computational tool for the efficient analysis of dose-volume histograms for radiation therapy treatment plans

    Science.gov (United States)

    Pyakuryal, Anil; Myint, W. Kenji; Gopalakrishnan, Mahesh; Jang, Sunyoung; Logemann, Jerilyn A.; Mittal, Bharat B.

    2010-01-01

    A Histogram Analysis in Radiation Therapy (HART) program was primarily developed to increase the efficiency and accuracy of dose–volume histogram (DVH) analysis of large quantities of patient data in radiation therapy research. The program was written in MATLAB to analyze patient plans exported from the treatment planning system (Pinnacle3) in the American Association of Physicists in Medicine/Radiation Therapy Oncology Group (AAPM/RTOG) format. HART-computed DVH data was validated against manually extracted data from the planning system for five head and neck cancer patients treated with the intensity-modulated radiation therapy (IMRT) technique. HART calculated over 4000 parameters from the differential DVH (dDVH) curves for each patient in approximately 10–15 minutes. Manual extraction of this amount of data required 5 to 6 hours. The normalized root mean square deviation (NRMSD) for the HART–extracted DVH outcomes was less than 1%, or within 0.5% distance-to-agreement (DTA). This tool is supported with various user-friendly options and graphical displays. Additional features include optimal polynomial modeling of DVH curves for organs, treatment plan indices (TPI) evaluation, plan-specific outcome analysis (POA), and spatial DVH (zDVH) and dose surface histogram (DSH) analyses, respectively. HART is freely available to the radiation oncology community. PMID:20160690

  19. Predictors of overall satisfaction of cancer patients undergoing radiation therapy

    Directory of Open Access Journals (Sweden)

    Becker-Schiebe M

    2015-09-01

    Full Text Available Martina Becker-Schiebe,1,2 Uwe Pinkert,1 Tahera Ahmad,1 Christof Schäfer,3 Wolfgang Hoffmann,1 Heiko Franz4 1Department of Radiotherapy and Radio-Oncology, Städtisches Klinikum Braunschweig gGmbH, Braunschweig, 2Radiation Oncology, Hannover Medical School, Hannover, 3Radiation Oncology Straubing, University of Regensburg, Regensburg, 4Department of Gynecology and Obstetrics, Städtisches Klinikum Braunschweig gGmbH, Braunschweig, Germany Background: Reporting the experiences and satisfaction of patients, as well as their quality of care scores is an emerging recommendation in health care systems. Many aspects of patients’ experience determine their overall satisfaction. The aim of this evaluation was to define the main factors contributing to the satisfaction of patients undergoing radiotherapy in an outpatient setting. Patients and methods: A total of 1,710 patients with a histologically proven cancer, who were treated in our department between 2012 and 2014, were recruited for this prospective evaluation. At the end of therapy, each patient was asked to grade the skills and the care provided by radiation therapists, physicians, and physician’s assistants, as well as the overall satisfaction during therapy. Statistical analysis was performed to determine which parameters had the greatest influence on overall satisfaction. Results: Overall satisfaction with the provided care was high with a mean satisfaction score of 1.4. Significant correlations were found between overall satisfaction and each of the following survey items: courtesy, protection of privacy, professional skills and care provided by the radiation therapists and physicians, accuracy of provided information, and cleanliness. Linear regression analysis demonstrated that courteous behavior and the protection of privacy were the strongest predictors for overall satisfaction (P<0.001, followed by care and skills of physicians and radiation therapists. Patients suffering from head

  20. Hyperbaric Oxygen Therapy for Radiation-Induced Cystitis and Proctitis

    Energy Technology Data Exchange (ETDEWEB)

    Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W. [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States); Komarnicky, Lydia T., E-mail: lydia.komarnicky-kocher@drexelmed.edu [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)

    2012-11-01

    Purpose: To provide a retrospective analysis of the efficacy of hyperbaric oxygen therapy (HBOT) for treating hemorrhagic cystitis (HC) and proctitis secondary to pelvic- and prostate-only radiotherapy. Methods and Materials: Nineteen patients were treated with HBOT for radiation-induced HC and proctitis. The median age at treatment was 66 years (range, 15-84 years). The range of external-beam radiation delivered was 50.0-75.6 Gy. Bleeding must have been refractory to other therapies. Patients received 100% oxygen at 2.0 atmospheres absolute pressure for 90-120 min per treatment in a monoplace chamber. Symptoms were retrospectively scored according to the Late Effects of Normal Tissues-Subjective, Objective, Management, Analytic (LENT-SOMA) scale to evaluate short-term efficacy. Recurrence of hematuria/hematochezia was used to assess long-term efficacy. Results: Four of the 19 patients were lost to follow-up. Fifteen patients were evaluated and received a mean of 29.8 dives: 11 developed HC and 4 proctitis. All patients experienced a reduction in their LENT-SOMA score. After completion of HBOT, the mean LENT-SOMA score was reduced from 0.78 to 0.20 in patients with HC and from 0.66 to 0.26 in patients with proctitis. Median follow-up was 39 months (range, 7-70 months). No cases of hematuria were refractory to HBOT. Complete resolution of hematuria was seen in 81% (n = 9) and partial response in 18% (n = 2). Recurrence of hematuria occurred in 36% (n = 4) after a median of 10 months. Complete resolution of hematochezia was seen in 50% (n = 2), partial response in 25% (n = 1), and refractory bleeding in 25% (n = 1). Conclusions: Hyperbaric oxygen therapy is appropriate for radiation-induced HC once less time-consuming therapies have failed to resolve the bleeding. In these conditions, HBOT is efficacious in the short and long term, with minimal side effects.

  1. The concept and evolution of involved site radiation therapy for lymphoma

    DEFF Research Database (Denmark)

    Specht, Lena; Yahalom, Joachim

    2015-01-01

    We describe the development of radiation therapy for lymphoma from extended field radiotherapy of the past to modern conformal treatment with involved site radiation therapy based on advanced imaging, three-dimensional treatment planning and advanced treatment delivery techniques. Today, radiation...... therapy is part of the multimodality treatment of lymphoma, and the irradiated tissue volume is much smaller than before, leading to highly significant reductions in the risks of long-term complications....

  2. Disparities in the Use of Postmastectomy Radiation Therapy for Inflammatory Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Loveland-Jones, Catherine [MD Anderson Cancer Center at Cooper, Camden, New Jersey (United States); Lin, Heather; Shen, Yu; Bedrosian, Isabelle; Shaitelman, Simona; Kuerer, Henry [University of Texas, MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy; Ueno, Naoto; Valero, Vicente [University of Texas, MD Anderson Cancer Center, Houston, Texas (United States); MD Anderson Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, Houston, Texas (United States); Babiera, Gildy, E-mail: gvbabiera@mdanderson.org [University of Texas, MD Anderson Cancer Center, Houston, Texas (United States); MD Anderson Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, Houston, Texas (United States)

    2016-07-15

    Purpose: Although radiation therapy improves locoregional control and survival for inflammatory breast cancer (IBC), it is underused in this population. The purpose of this study was to identify variables associated with the underuse of postmastectomy radiation therapy (PMRT) for IBC. Methods and Materials: Using the 1998 to 2011 National Cancer Data Base, we identified 8273 women who underwent mastectomy for nonmetastatic IBC. We used logistic regression modeling to determine the demographic, tumor, and treatment variables associated with the underuse of PMRT. Results: Although the use of PMRT increased over time, a total of 30.3% of our cohort did not receive PMRT. On multivariate analysis, variables associated with the underuse of PMRT for IBC included the following (all P<.05): Medicare insurance (odds ratio [OR] = 0.70), annual income <$34,999 (<$30,000: OR=0.79; $30,000-$34,999: OR=0.82), cN2 and cN0 disease (cN2: OR=0.71; cN0: OR=0.63), failure to receive chemotherapy and hormone therapy (chemotherapy: OR=0.15; hormone therapy: OR=0.35), treatment at lower-volume centers (OR=0.83), and treatment in the South and West (South: OR=0.73; West: OR=0.80). Greater distance between patient's residence and radiation facility was also associated with the underuse of PMRT (P=.0001). Conclusions: Although the use of PMRT for IBC has increased over time, it continues to be underused. Disparities related to a variety of variables impact which IBC patients receive PMRT. A concerted effort must be made to address these disparities in order to optimize the outcomes for IBC.

  3. Investigation of Radiation Protection Methodologies for Radiation Therapy Shielding Using Monte Carlo Simulation and Measurement

    Science.gov (United States)

    Tanny, Sean

    The advent of high-energy linear accelerators for dedicated medical use in the 1950's by Henry Kaplan and the Stanford University physics department began a revolution in radiation oncology. Today, linear accelerators are the standard of care for modern radiation therapy and can generate high-energy beams that can produce tens of Gy per minute at isocenter. This creates a need for a large amount of shielding material to properly protect members of the public and hospital staff. Standardized vault designs and guidance on shielding properties of various materials are provided by the National Council on Radiation Protection (NCRP) Report 151. However, physicists are seeking ways to minimize the footprint and volume of shielding material needed which leads to the use of non-standard vault configurations and less-studied materials, such as high-density concrete. The University of Toledo Dana Cancer Center has utilized both of these methods to minimize the cost and spatial footprint of the requisite radiation shielding. To ensure a safe work environment, computer simulations were performed to verify the attenuation properties and shielding workloads produced by a variety of situations where standard recommendations and guidance documents were insufficient. This project studies two areas of concern that are not addressed by NCRP 151, the radiation shielding workload for the vault door with a non-standard design, and the attenuation properties of high-density concrete for both photon and neutron radiation. Simulations have been performed using a Monte-Carlo code produced by the Los Alamos National Lab (LANL), Monte Carlo Neutrons, Photons 5 (MCNP5). Measurements have been performed using a shielding test port designed into the maze of the Varian Edge treatment vault.

  4. Results of conservative surgery and radiation therapy for breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Osteen, R.T.; Smith, B.L. (Harvard Medical School, Boston, MA (USA))

    1990-10-01

    For stage I or II breast cancer, conservative surgery and radiation therapy are as effective as modified radical or radical mastectomy. In most cases, cosmetic considerations and the availability of therapy are the primary concerns. The extent of a surgical resection less than a mastectomy has not been a subject of a randomized trial and is controversial. It appears that removal of a quadrant of the breast for small lesions is safe but excessive. It may be possible to limit the breast resection to gross tumor removal for most patients while using wider resections for patients with an extensive intraductal component or for invasive lobular carcinoma. It also appears that excluding patients from breast conservation on the basis of positive margins on the first attempt at tumor excision may be unnecessarily restrictive. Although patients with an extensive intraductal component or invasive lobular carcinoma should have negative margins, it appears that a patient with predominantly invasive ductal carcinoma can be treated without re-excision if all gross tumor has been resected and there is no reason to suspect extensive microscopic disease. Patients with indeterminate margins should have a re-excision. Axillary dissection provides prognostic information and prevents progression of the disease within the axilla. Axillary dissections limited to level I will accurately identify a substantial number of patients who have pathologically positive but clinically negative nodes. When combined with radiation therapy to the axilla, a level I dissection results in a limited number of patients with progressive axillary disease. Patients with pathologically positive axillas and patients at particularly high risk for systemic disease because of the extent of axillary node involvement can be identified by dissections of levels I and II. 60 references.

  5. The peer review system (PRS) for quality assurance and treatment improvement in radiation therapy

    Science.gov (United States)

    Le, Anh H. T.; Kapoor, Rishabh; Palta, Jatinder R.

    2012-02-01

    Peer reviews are needed across all disciplines of medicine to address complex medical challenges in disease care, medical safety, insurance coverage handling, and public safety. Radiation therapy utilizes technologically advanced imaging for treatment planning, often with excellent efficacy. Since planning data requirements are substantial, patients are at risk for repeat diagnostic procedures or suboptimal therapeutic intervention due to a lack of knowledge regarding previous treatments. The Peer Review System (PRS) will make this critical radiation therapy information readily available on demand via Web technology. The PRS system has been developed with current Web technology, .NET framework, and in-house DICOM library. With the advantages of Web server-client architecture, including IIS web server, SOAP Web Services and Silverlight for the client side, the patient data can be visualized through web browser and distributed across multiple locations by the local area network and Internet. This PRS will significantly improve the quality, safety, and accessibility, of treatment plans in cancer therapy. Furthermore, the secure Web-based PRS with DICOM-RT compliance will provide flexible utilities for organization, sorting, and retrieval of imaging studies and treatment plans to optimize the patient treatment and ultimately improve patient safety and treatment quality.

  6. Clinical significance of radiation therapy in breast recurrence and prognosis in breast-conserving surgery

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Reiki; Nagao, Kazuharu; Miyayama, Haruhiko [Kumamoto City Hospital (Japan)] [and others

    1999-03-01

    Significant risk factors for recurrence of breast cancer after breast-conserving therapy, which has become a standard treatment for breast cancer, are positive surgical margins and the failure to perform radiation therapy. In this study, we evaluated the clinical significance of radiation therapy after primary surgery or breast recurrence. In 344 cases of breast-conserving surgery, disease recurred in 43 cases (12.5%), which were classified as follows: 17 cases of breast recurrence, 13 cases of breast and distant metastasis, and 13 cases of distant metastasis. Sixty-two patients (16.7%) received radiation therapy. A positive surgical margin and younger age were significant risk factors for breast recurrence in patients not receiving postoperative radiation therapy but not in patients receiving radiation therapy. Radiation therapy may be beneficial for younger patients with positive surgical margins. Furthermore, radiation therapy after recurrence was effective in the cases not treated with postoperative radiation but not in cases with inflammatory recurrence. Patients with breast recurrence alone had significantly higher survival rates than did patients with distant metastases regardless of breast recurrence. These findings suggest that the adaptation criteria of radiation therapy for local control must be clarified. (author)

  7. Genomic Classifier Augments the Role of Pathological Features in Identifying Optimal Candidates for Adjuvant Radiation Therapy in Patients With Prostate Cancer: Development and Internal Validation of a Multivariable Prognostic Model.

    Science.gov (United States)

    Dalela, Deepansh; Santiago-Jiménez, María; Yousefi, Kasra; Karnes, R Jeffrey; Ross, Ashley E; Den, Robert B; Freedland, Stephen J; Schaeffer, Edward M; Dicker, Adam P; Menon, Mani; Briganti, Alberto; Davicioni, Elai; Abdollah, Firas

    2017-06-20

    Purpose Despite documented oncologic benefit, use of postoperative adjuvant radiotherapy (aRT) in patients with prostate cancer is still limited in the United States. We aimed to develop and internally validate a risk-stratification tool incorporating the Decipher score, along with routinely available clinicopathologic features, to identify patients who would benefit the most from aRT. Patient and Methods Our cohort included 512 patients with prostate cancer treated with radical prostatectomy at one of four US academic centers between 1990 and 2010. All patients had ≥ pT3a disease, positive surgical margins, and/or pathologic lymph node invasion. Multivariable Cox regression analysis tested the relationship between available predictors (including Decipher score) and clinical recurrence (CR), which were then used to develop a novel risk-stratification tool. Our study adhered to the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis guidelines for development of prognostic models. Results Overall, 21.9% of patients received aRT. Median follow-up in censored patients was 8.3 years. The 10-year CR rate was 4.9% vs. 17.4% in patients treated with aRT versus initial observation ( P 0.6 were independent predictors of CR (all P < .01). The cumulative number of risk factors was 0, 1, 2, and 3 to 4 in 46.5%, 28.9%, 17.2%, and 7.4% of patients, respectively. aRT was associated with decreased CR rate in patients with two or more risk factors (10-year CR rate 10.1% in aRT v 42.1% in initial observation; P = .012), but not in those with fewer than two risk factors ( P = .18). Conclusion Using the new model to indicate aRT might reduce overtreatment, decrease unnecessary adverse effects, and reduce risk of CR in the subset of patients (approximately 25% of all patients with aggressive pathologic disease in our cohort) who benefit from this therapy.

  8. Estimating the excess lifetime risk of radiation induced secondary malignancy (SMN) in pediatric patients treated with craniospinal irradiation (CSI): Conventional radiation therapy versus helical intensity modulated radiation therapy.

    Science.gov (United States)

    Holmes, Jordan A; Chera, Bhishamjit S; Brenner, David J; Shuryak, Igor; Wilson, Adam K; Lehman-Davis, Misty; Fried, David V; Somasundaram, Vivek; Lian, Jun; Cullip, Tim; Marks, Lawrence B

    To quantify the risk of radiation-induced second malignancies (SMN) in pediatric patients receiving craniospinal irradiation (CSI) either with 3-dimensional conformal radiation therapy (Conv CSI) or tomotherapy helical intensity modulated radiation therapy (Tomo CSI). A novel predictive model that accounts for short- and long-term carcinogenesis was incorporated into our institutional treatment planning system to quantify the lifetime risk of SMN in incidentally irradiated organs. Five pediatric patients previously treated with CSI were studied. For each case, Conv CSI and Tomo CSI plans were computed. The excess absolute number of SMN was computed for each plan for each patient. For female patients, age was varied to assess its impact. Tomo CSI has a much higher risk than Conv CSI for breast cancer. Tomo has a slightly increased risk for the lung, and conventional has a slightly higher risk for the thyroid. Both techniques have intermediate risks to the pancreas and stomach, and lesser risks to the bladder and rectum. For the breast, the magnitude of the absolute risks varied with age: 14.2% versus 7.4% (Tomo vs Conv) age 5; 16.9% versus 7.6% age 10, and 18.6% versus 8.0% age 15. Tomo has a higher risk for inducing breast and lung second cancers, and when using Tomo-based intensity modulated radiation therapy, care should be taken to avoid incidental radiation to the breast. When planning CSI, one needs to balance these cancer risks against other normal tissue effects. Copyright © 2016. Published by Elsevier Inc.

  9. FINITE ELEMENT ANALYSIS FOR OPTIMIZING ANTENNA FOR MICROWAVE COAGULATION THERAPY

    Directory of Open Access Journals (Sweden)

    MARWAHA S.

    2012-08-01

    Full Text Available Microwave coagulation therapy (MCT is emerging as an attractive modality for thermal therapy of soft tissues targeted in short periods of time, making it particularly suitable for ablation of hepatic and other tumors. In this field of microwave coagulation therapy, the use of minimally invasive antenna is recognized as a very promising technique for the treatment of small tumors because a very thin antenna can be easily inserted inside the body and precisely localized using the advanced 3D imaging techniques and surgical robots. The authors investigated the microwave coaxial antenna operating at 2.45 GHz by varying the slots size for the removal of liver tumor. The analysis was done using 2D finite element modeling. By several optimization steps the antenna is simulated and optimized by comparing the values of specific absorption rate (SAR, mesh statistics and temperature distributions in tissue generated by the antenna with the variations of dimensions of slot from 1 mm to 1.7 mm.

  10. Therapy with {sup 90}Y microspheres: radiation protection in new medical therapies; Terapia con microesferas de {sup 90}Y: proteccion radiologica en nuevas terapias medicas

    Energy Technology Data Exchange (ETDEWEB)

    Rojo, Ana; Puerta, Nancy, E-mail: arojo@arn.gob.ar [Autoridad Regulatoria Nuclear (ARN), Buenos Aires (Argentina)

    2013-07-01

    Primary liver cancer is one of the most frequent in the world and with a low cure rate. Radioembolization using 90y spheres is a promising treatment of this pathology and involves the percutaneous vascular application of radioisotope-labeled the order of Micron size particles. The advantages of this technique include the permit administered high doses of radiation to small volumes with low relative toxicity, offer the possibility of treating all the liver including microscopic tumors, and finally, the feasibility of combined with other therapies. Radiation protection in new medical therapies requires justification and optimization, as requirements for their implementation. The application of the principle of optimization in the context of the protection of the patient must be the minimum that it can be reasonably reached compatible with the required doses of treatment dose to healthy tissue. With {sup 90}Y microspheres therapy this optimization applies to the activity of 90y which is administered to the patient, and estimation methods are postulated. in this work are analyzed comparatively these methods, described the early physicists, equations and the limitations of each. Finally, it is concluded that the optimal method to be implemented for the evaluation of the activity of {sup 90}Y manage must be based in a voxel dosimetric model specific for each patient, however, the partitional method may be a good alternative if you don't have the tools to apply the method.

  11. Radiation recall dermatitis triggered by sorafenib after radiation therapy for hepatocellular carcinoma

    Science.gov (United States)

    Kim, Gwi Eon; Song, Hee-Sung; Ahn, Ki Jung; Kim, Young Suk

    2017-01-01

    Sorafenib is widely used for unresectable and metastatic hepatocellular carcinomas. Radiation recall dermatitis (RRD) is an acute inflammatory reaction confined to previously irradiated skin that occurs after the administration of certain drugs. RRD after sorafenib treatment is rare; five cases have been reported thus far. We describe a 44-year-old man irradiated for chest wall bone metastasis from hepatocellular carcinoma. Eight days after radiotherapy completion, systemic therapy for metastatic hepatocellular carcinoma was initiated with sorafenib treatment. Eleven days after starting sorafenib, the patient complained of erythematous rash with pruritus in the chest wall, in a location consistent with the previous radiation field. Sorafenib was continued at the same dose, despite the RRD. The skin reaction subsided over the next 2 weeks without any medical intervention. PMID:29037022

  12. Radiation recall dermatitis triggered by sorafenib after radiation therapy for hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gwi Eon; Song, Hee Sung; Kim, Young Suk [Jeju National University Hospital, Jeju National University School of Medicine, Jeju (Korea, Republic of); Ahn, Ki Jung [Dept. of Radiation Oncology, Inje University Busan Paik Hospital, Inje University of Medicine, Busan (Korea, Republic of)

    2017-09-15

    Sorafenib is widely used for unresectable and metastatic hepatocellular carcinomas. Radiation recall dermatitis (RRD) is an acute inflammatory reaction confined to previously irradiated skin that occurs after the administration of certain drugs. RRD after sorafenib treatment is rare; five cases have been reported thus far. We describe a 44-year-old man irradiated for chest wall bone metastasis from hepatocellular carcinoma. Eight days after radiotherapy completion, systemic therapy for metastatic hepatocellular carcinoma was initiated with sorafenib treatment. Eleven days after starting sorafenib, the patient complained of erythematous rash with pruritus in the chest wall, in a location consistent with the previous radiation field. Sorafenib was continued at the same dose, despite the RRD. The skin reaction subsided over the next 2 weeks without any medical intervention.

  13. A case of post-radiation constrictive pericarditis developing 12 years after radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sakuraba, Motoki; Tanaka, Jun-ichi; Ikeda, Shingo; Kigawa, Ikutaro; Fukuda, Sachito; Wanibuchi, Yasuhiko [Mitsui Memorial Hospital, Tokyo (Japan)

    1997-11-01

    A 70-year-old woman underwent radical mastectomy for carcinoma of the left breast in 1982. Postoperative radiation therapy was given in a total dose of 50 Gy for parasternal and left subclavian nodes. Symptoms of heart failure such as exertional dyspnea, facial edema, and hepatomegaly manifested in 1992. Cardiac catheterization revealed marked elevation of mean right atrial pressure and right ventricular end-diastolic pressure. The pressure wave form of the right ventricle showed the so called ``dip and plateau`` feature. Pericardiectomy without using extracorporeal circulation was performed in 1994. Operative findings and pathological study results were compatible with radiation-induced constrictive pericarditis. She rapidly recovered from heart failure after this operation, and has done very well to date. (author)

  14. Size-dependent radiosensitization of PEG-coated gold nanoparticles for cancer radiation therapy

    CERN Document Server

    Zhang, Xiao-Dong; Shen, Xiu; Chen, Jie; Sun, Yuan-Ming; Liu, Pei-Xun; Liang, Xing-Jie

    2012-01-01

    Gold nanoparticles have been conceived as a radiosensitizer in cancer radiation therapy, but one of the important questions for primary drug screening is what size of gold nanoparticles can optimally enhance radiation effects. Herein, we perform in vitro and in vivo radiosensitization studies of 4.8, 12.1, 27.3, and 46.6 nm PEG-coated gold nanoparticles. In vitro results show that all sizes of the PEG-coated gold nanoparticles can cause a significant decrease in cancer cell survival after gamma radiation. 12.1 and 27.3 nm PEG-coated gold nanoparticles have dispersive distributions in the cells and have stronger sensitization effects than 4.8 and 46.6 nm particles by both cell apoptosis and necrosis. Further, in vivo results also show all sizes of the PEG-coated gold nanoparticles can decrease tumor volume and weight after 5 Gy radiations, and 12.1 and 27.3 nm PEG-coated gold nanoparticles have greater sensitization effects than 4.8 and 46.6 nm particles, which can lead to almost complete disappearance of the ...

  15. [Benchmark experiment to verify radiation transport calculations for dosimetry in radiation therapy].

    Science.gov (United States)

    Renner, Franziska

    2016-09-01

    Monte Carlo simulations are regarded as the most accurate method of solving complex problems in the field of dosimetry and radiation transport. In (external) radiation therapy they are increasingly used for the calculation of dose distributions during treatment planning. In comparison to other algorithms for the calculation of dose distributions, Monte Carlo methods have the capability of improving the accuracy of dose calculations - especially under complex circumstances (e.g. consideration of inhomogeneities). However, there is a lack of knowledge of how accurate the results of Monte Carlo calculations are on an absolute basis. A practical verification of the calculations can be performed by direct comparison with the results of a benchmark experiment. This work presents such a benchmark experiment and compares its results (with detailed consideration of measurement uncertainty) with the results of Monte Carlo calculations using the well-established Monte Carlo code EGSnrc. The experiment was designed to have parallels to external beam radiation therapy with respect to the type and energy of the radiation, the materials used and the kind of dose measurement. Because the properties of the beam have to be well known in order to compare the results of the experiment and the simulation on an absolute basis, the benchmark experiment was performed using the research electron accelerator of the Physikalisch-Technische Bundesanstalt (PTB), whose beam was accurately characterized in advance. The benchmark experiment and the corresponding Monte Carlo simulations were carried out for two different types of ionization chambers and the results were compared. Considering the uncertainty, which is about 0.7 % for the experimental values and about 1.0 % for the Monte Carlo simulation, the results of the simulation and the experiment coincide. Copyright © 2015. Published by Elsevier GmbH.

  16. Prioritized efficiency optimization for intensity modulated proton therapy

    Science.gov (United States)

    Müller, Birgit S.; Wilkens, Jan J.

    2016-12-01

    A high dosimetric quality and short treatment time are major goals in radiotherapy planning. Intensity modulated proton therapy (IMPT) plans obtain dose distributions of great conformity but often result in long delivery times which are typically not incorporated into the optimization process. We present an algorithm to optimize delivery efficiency of IMPT plans while maintaining plan quality, and study the potential trade-offs of these interdependent objectives. The algorithm is based on prioritized optimization, a stepwise approach to implemented objectives. First the quality of the plan is optimized. The second step of the prioritized efficiency optimization (PrEfOpt) routine offers four alternatives for reducing delivery time: minimization of the total spot weight sum (A), maximization of the lowest spot intensity of each energy layer (B), elimination of low-weighted spots (C) or energy layers (D). The trade-off between dosimetric quality (step I) and treatment time (step II) is controlled during the optimization by option-dependent parameters. PrEfOpt was applied to a clinical patient case, and plans for different trade-offs were calculated. Delivery times were simulated for two virtual facilities with constant and variable proton current, i.e. independent and dependent on the optimized spot weight distributions. Delivery times decreased without major degradation of plan quality; absolute time reductions varied with the applied method and facility type. Minimizing the total spot weight sum (A) reduced times by 28% for a similar plan quality at a constant current (changes of minimum dose in the target  <1%). For a variable proton current, eliminating low-weighted spots (C) led to remarkably faster delivery (16%). The implementation of an efficiency-optimization step into the optimization process can yield reduced delivery times with similar plan qualities. A potential clinical application of PrEfOpt is the generation of multiple plans with different trade

  17. An analysis of the incidence and related factors for radiation dermatitis in breast cancer patients who receive radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sun Young; Kwon, Hyoung Cheol; Kim, Jung Soo [Dept. of Radiation Oncology, Chonbuk National University Hospital, Jeonju (Korea, Republic of); Lee, Heui Kwan [Prebyterian Medical Center, Jeonju (Korea, Republic of)

    2010-11-15

    We analyzed the incidence and related factors of radiation dermatitis; at first, to recognize whether a decrease in radiation dermatitis is possible or not in breast cancer patients who received radiation therapy. Of 338 patients, 284 with invasive breast cancer who received breast conservation surgery with radiotherapy at Chonbuk National University Hospital from January 2007 to June 2009 were evaluated. Patients who also underwent bolus, previous contralateral breast irradiation and irradiation on both breasts were excluded. For patients who appeared to have greater than moderate radiation dermatitis, the incidence and relating factors for radiation dermatitis were analyzed retrospectively. A total of 207 and 77 patients appeared to have RTOG grade 0/1 or above RTOG grade 2 radiation dermatitis, respectively. The factors found to be statistically significant for the 77 patients who appeared to have greater than moderate radiation dermatitis include the presence of lymphocele due to the stasis of lymph and lymph edema which affect the healing disturbance of radiation dermatitis (p=0.003, p=0.001). Moreover, an allergic reaction to plaster due to the immune cells of skin and the activation of cytokine and concomitant hormonal therapy were also statistically significant factors (p=0.001, p=0.025). Most of the breast cancer patients who received radiation therapy appeared to have a greater than mild case of radiation dermatitis. Lymphocele, lymphedema, an allergy to plaster and concomitant hormonal therapy which affect radiation dermatitis were found to be significant factors. Consequently, we should eliminate lymphocele prior to radiation treatment for patients who appear to have an allergic reaction to plaster. We should also instruct patients of methods to maintain skin moisture if they appear to have a greater than moderate case of radiation dermatitis.

  18. Radiation Hardness of dSiPM Sensors in a Proton Therapy Radiation Environment

    Science.gov (United States)

    Diblen, Faruk; Buitenhuis, Tom; Solf, Torsten; Rodrigues, Pedro; van der Graaf, Emiel; van Goethem, Marc-Jan; Brandenburg, Sytze; Dendooven, Peter

    2017-07-01

    In vivo verification of dose delivery in proton therapy by means of positron emission tomography (PET) or prompt gamma imaging is mostly based on fast scintillation detectors. The digital silicon photomultiplier (dSiPM) allows excellent scintillation detector timing properties and is thus being considered for such verification methods. We present here the results of the first investigation of radiation damage to dSiPM sensors in a proton therapy radiation environment. Radiation hardness experiments were performed at the AGOR cyclotron facility at the KVI-Center for Advanced Radiation Technology, University of Groningen. A 150-MeV proton beam was fully stopped in a water target. In the first experiment, bare dSiPM sensors were placed at 25 cm from the Bragg peak, perpendicular to the beam direction, a geometry typical for an in situ implementation of a PET or prompt gamma imaging device. In the second experiment, dSiPM-based PET detectors containing lutetium yttrium orthosilicate scintillator crystal arrays were placed at 2 and 4 m from the Bragg peak, perpendicular to the beam direction; resembling an in-room PET implementation. Furthermore, the experimental setup was simulated with a Geant4-based Monte Carlo code in order to determine the angular and energy distributions of the neutrons and to determine the 1-MeV equivalent neutron fluences delivered to the dSiPM sensors. A noticeable increase in dark count rate (DCR) after an irradiation with about 108 1-MeV equivalent neutrons/cm2 agrees with observations by others for analog SiPMs, indicating that the radiation damage occurs in the single photon avalanche diodes and not in the electronics integrated on the sensor chip. It was found that in the in situ location, the DCR becomes too large for successful operation after the equivalent of a few weeks of use in a proton therapy treatment room (about 5 × 1013 protons). For PET detectors in an in-room setup, detector performance was unchanged even after an

  19. Modern Radiation Therapy for Primary Cutaneous Lymphomas: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Lena, E-mail: lena.specht@regionh.dk [Departments of Oncology and Hematology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Dabaja, Bouthaina [Division of Radiation Oncology, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Illidge, Tim [Institute of Cancer Sciences, University of Manchester, Manchester Academic Health Sciences Centre, The Christie National Health Service Foundation Trust, Manchester (United Kingdom); Wilson, Lynn D. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Hoppe, Richard T. [Department of Radiation Oncology, Stanford University, Stanford, California (United States)

    2015-05-01

    Primary cutaneous lymphomas are a heterogeneous group of diseases. They often remain localized, and they generally have a more indolent course and a better prognosis than lymphomas in other locations. They are highly radiosensitive, and radiation therapy is an important part of the treatment, either as the sole treatment or as part of a multimodality approach. Radiation therapy of primary cutaneous lymphomas requires the use of special techniques that form the focus of these guidelines. The International Lymphoma Radiation Oncology Group has developed these guidelines after multinational meetings and analysis of available evidence. The guidelines represent an agreed consensus view of the International Lymphoma Radiation Oncology Group steering committee on the use of radiation therapy in primary cutaneous lymphomas in the modern era.

  20. Doses to Carotid Arteries After Modern Radiation Therapy for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Maraldo, M.V.; Brodin, Nils Patrik; Aznar, Marianne Camille

    2013-01-01

    Hodgkin lymphoma (HL) survivors are at an increased risk of stroke because of carotid artery irradiation. However, for early-stage HL involved node radiation therapy (INRT) reduces the volume of normal tissue exposed to high doses. Here, we evaluate 3-dimensional conformal radiation therapy (3D......-CRT), volumetric-modulated arc therapy (VMAT), and proton therapy (PT) delivered as INRT along with the extensive mantle field (MF) by comparing doses to the carotid arteries and corresponding risk estimates....

  1. Multimodal hypoxia imaging and intensity modulated radiation therapy for unresectable non-small-cell lung cancer: the HIL trial

    Directory of Open Access Journals (Sweden)

    Askoxylakis Vasileios

    2012-09-01

    Full Text Available Abstract Background Radiotherapy, preferably combined with chemotherapy, is the treatment standard for locally advanced, unresectable non-small cell lung cancer (NSCLC. The tumor response to different therapy protocols is variable, with hypoxia known to be a major factor that negatively influences treatment effectiveness. Visualisation of tumor hypoxia prior to the use of modern radiation therapy strategies, such as intensity modulated radiation therapy (IMRT, might allow optimized dose applications to the target volume, leading to improvement of therapy outcome. 18 F-fluoromisonidazole dynamic positron emission tomography and computed tomography (18 F-FMISO dPET-CT and functional magnetic resonance imaging (functional MRI are attractive options for imaging tumor hypoxia. Methods/design The HIL trial is a single centre study combining multimodal hypoxia imaging with 18 F-FMISO dPET-CT and functional MRI, with intensity modulated radiation therapy (IMRT in patients with inoperable stage III NSCLC. 15 patients will be recruited in the study. All patients undergo initial FDG PET-CT and serial 18 F-FMISO dPET-CT and functional MRI before treatment, at week 5 of radiotherapy and 6 weeks post treatment. Radiation therapy is performed as inversely planned IMRT based on 4D-CT. Discussion Primary objectives of the trial are to characterize the correlation of 18 F-FMISO dPET-CT and functional MRI for tumor hypoxia imaging in NSCLC and evaluate possible effects of radiation therapy on tumor re-oxygenation. Further objectives include the generation of data regarding the prognostic value of 18 F-FMISO dPET-CT and functional MRI for locoregional control, progression free survival and overall survival of NSCLC treated with IMRT, which will form the basis for larger clinical trials focusing on possible interactions between tumor oxygenation and radiotherapy outcome. Trial registration The ClinicalTrials.gov protocol ID is NCT01617980

  2. Scatter correction for cone-beam CT in radiation therapy.

    Science.gov (United States)

    Zhu, Lei; Xie, Yaoqin; Wang, Jing; Xing, Lei

    2009-06-01

    Cone-beam CT (CBCT) is being increasingly used in modern radiation therapy for patient setup and adaptive replanning. However, due to the large volume of x-ray illumination, scatter becomes a rather serious problem and is considered as one of the fundamental limitations of CBCT image quality. Many scatter correction algorithms have been proposed in literature, while a standard practical solution still remains elusive. In radiation therapy, the same patient is scanned repetitively during a course of treatment, a natural question to ask is whether one can obtain the scatter distribution on the first day of treatment and then use the data for scatter correction in the subsequent scans on different days. To realize this scatter removal scheme, two technical pieces must be in place: (i) A strategy to obtain the scatter distribution in on-board CBCT imaging and (ii) a method to spatially match a prior scatter distribution with the on-treatment CBCT projection data for scatter subtraction. In this work, simple solutions to the two problems are provided. A partially blocked CBCT is used to extract the scatter distribution. The x-ray beam blocker has a strip pattern, such that partial volume can still be accurately reconstructed and the whole-field scatter distribution can be estimated from the detected signals in the shadow regions using interpolation/extrapolation. In the subsequent scans, the patient transformation is determined using a rigid registration of the conventional CBCT and the prior partial CBCT. From the derived patient transformation, the measured scatter is then modified to adapt the new on-treatment patient geometry for scatter correction. The proposed method is evaluated using physical experiments on a clinical CBCT system. On the Catphan 600 phantom, the errors in Hounsfield unit (HU) in the selected regions of interest are reduced from about 350 to below 50 HU; on an anthropomorphic phantom, the error is reduced from 15.7% to 5.4%. The proposed method

  3. Tangential intensity modulated radiation therapy (IMRT) to the intact breast.

    Science.gov (United States)

    Dean, Jenna; Hansen, Carmen J; Westhuyzen, Justin; Waller, Brett; Turnbull, Kirsty; Wood, Maree; Last, Andrew

    2016-12-01

    Inverse-planned intensity modulated radiation therapy (IP-IMRT) has potential benefits over other techniques for tangential intact breast radiotherapy. Possible benefits include increased homogeneity, faster planning time, less inter-planner variability and lower doses to organs at risk (OAR). We therefore conducted a pilot study of previously treated intact breast patients to compare the current forward-planned 'field-in-field' technique (FP-IMRT) with an IP-IMRT alternative. The IP-IMRT plans of 20 patients were generated from a template created for the planning system. All patients were prescribed adjuvant whole breast radiotherapy using a hypofractionated regimen of 40.05 Gy in 15 fractions over 3 weeks. Plans were assessed based on visual inspection of coverage as well as statistical analysis and compared to the clinically acceptable FP-IMRT plans. Patients were planned retrospectively in Monaco 3.2(®) using a laterality-specific, tangential planning template. Minor adjustments were made as necessary to meet the planning criteria in the protocol. Dose coverage, maximums, homogeneity indices and doses to OAR were recorded. The IP-IMRT plans provided more consistent coverage (38.18 Gy vs. 36.08 Gy of D95; P = 0.005), a comparable though higher average maximum (D2 = 42.52 Gy vs. 42.08 Gy; P = 0.0001), more homogeneous plans (homogeneity index = 0.908 vs. 0.861; P = 0.01) and somewhat lower V20 heart and lung doses (0.11% vs. 0.89% for heart; 5.4% vs. 7.52% for lung) than FP-IMRT (P > 0.05). Clinically acceptable plans have been generated using the IP-IMRT templates in Monaco. Improvements in consistency and quality were seen when compared to the FP-IMRT plans. The template-based process is an efficient method to inversely plan IMRT for breast patients. © 2016 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of

  4. Optimization and simplification of antiretroviral therapy for adults and children.

    Science.gov (United States)

    Ford, Nathan; Flexner, Charles; Vella, Stefano; Ripin, David; Vitoria, Marco

    2013-11-01

    The review reflects on opportunities and challenges for HIV treatment optimization for the next 5 years. Considering all currently available options, the fixed-dose combination of tenofovir + lamivudine (or emtricitabine) + efavirenz is considered as the best option for first-line treatment for the short to medium term. Second-line therapy will likely continue to be comprised of a boosted protease inhibitor in combination with two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), with potential for combining with integrase inhibitors. For children, there is potential for simplification and harmonization with adult antiretroviral regimens. First-line therapy for children younger than 3 years of age may be best delivered using two nucleoside reverse transcriptase inhibitors (NRTIs) and a boosted protease inhibitor; above 3 years of age, the standard of care is two NRTIs and a non-nucleoside reverse transcriptase inhibitor (NNRTI) as recommended for adults. Important research questions include the dosing and safety of new antiretroviral agents and formulations, particularly once-daily fixed-dose combinations, the role of integrase inhibitors and the optimal second-line regimen for NNRTI-exposed children who fail protease inhibitor-containing first-line regimens. Treatment simplification is critical to further antiretroviral therapy scaling-up and support long-term retention in care. Future guidance should consider the broader benefits of earlier antiretroviral therapy initiation beyond potential AIDS mortality reduction, notably mitigation of short- and long-term HIV-associated comorbidities, reduction of HIV transmission, increased retention in care, and enhancing programme simplification.

  5. Simultaneous reconstruction of temperature field and radiative properties by inverse radiation analysis using stochastic particle swarm optimization

    Directory of Open Access Journals (Sweden)

    Liu Dong

    2016-01-01

    Full Text Available Simultaneous reconstruction of temperature field and radiative properties including scattering albedo and extinction coefficient is presented in a two-dimensional (2-D rectangular, absorbing, emitting and isotropically scattering gray medium from the knowledge of the exit radiative intensities received by charge-coupled device (CCD cameras at boundary surfaces. The inverse problem is formulated as a non-linear optimization problem and solved by stochastic particle swarm optimization. The effects of particle swarm size, generation number, measurement errors, and optical thickness on the accuracy of the estimation, and computing time were investigated and the results show that the temperature field and radiative properties can be reconstructed well for the exact and noisy data, but radiative properties are harder to obtain than temperature field. Moreover, the extinction coefficient is more difficult to reconstruct than scattering albedo.

  6. Combinations of Radiation Therapy and Immunotherapy for Melanoma: A Review of Clinical Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Barker, Christopher A., E-mail: barkerc@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Postow, Michael A. [Department of Medicine, Melanoma and Sarcoma Oncology Service, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2014-04-01

    Radiation therapy has long played a role in the management of melanoma. Recent advances have also demonstrated the efficacy of immunotherapy in the treatment of melanoma. Preclinical data suggest a biologic interaction between radiation therapy and immunotherapy. Several clinical studies corroborate these findings. This review will summarize the outcomes of studies reporting on patients with melanoma treated with a combination of radiation therapy and immunotherapy. Vaccine therapies often use irradiated melanoma cells, and may be enhanced by radiation therapy. The cytokines interferon-α and interleukin-2 have been combined with radiation therapy in several small studies, with some evidence suggesting increased toxicity and/or efficacy. Ipilimumab, a monoclonal antibody which blocks cytotoxic T-lymphocyte antigen-4, has been combined with radiation therapy in several notable case studies and series. Finally, pilot studies of adoptive cell transfer have suggested that radiation therapy may improve the efficacy of treatment. The review will demonstrate that the combination of radiation therapy and immunotherapy has been reported in several notable case studies, series and clinical trials. These clinical results suggest interaction and the need for further study.

  7. Stereotactic Body Radiation Therapy (SBRT) for Unresectable Pancreatic Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Stauder, Michael C.; Miller, Robert C., E-mail: miller.robert@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States)

    2010-08-09

    Survival in patients with unresectable pancreatic carcinoma is poor. Studies by Mayo Clinic and the Gastrointestinal Tumor Study Group (GITSG) have established combined modality treatment with chemotherapy and radiation as the standard of care. Use of gemcitabine-based chemotherapy alone has also been shown to provide a benefit, but 5‑year overall survival still remains less than 5%. Conventional radiotherapy is traditionally delivered over a six week period and high toxicity is seen with the concomitant use of chemotherapy. In contrast, SBRT can be delivered in 3–5 days and, when used as a component of combined modality therapy with gemcitabine, disruption to the timely delivery of chemotherapy is minimal. Early single-institution reports of SBRT for unresectable pancreatic carcinoma demonstrate excellent local control with acceptable toxicity. Use of SBRT in unresectable pancreatic carcinoma warrants further investigation in order to improve the survival of patients with historically poor outcomes.

  8. Effects of Radiation Therapy on Established Neurogenic Heterotopic Ossification.

    Science.gov (United States)

    Lee, Chan Ho; Shim, Su Jung; Kim, Hyun Jung; Yang, Hyuna; Kang, Youn Joo

    2016-12-01

    Heterotopic ossification (HO) is frequently seen on rehabilitation units after spinal cord injuries, fractures, brain injuries, and limb amputations. Currently, there is no effective treatment for HO other than prophylaxis with anti-inflammatory medications, irradiation, and bisphosphonate administration. These prophylactic treatments are not effective for managing ectopic bone once it has formed. Here we describe three cases of established neurogenic HO treated with radiation therapy (RT). All patients had decreased serum alkaline phosphatase (ALP) and bone-specific ALP levels with decreased pain but increased range of motion immediately after RT. Post-treatment X-rays revealed no further growth of the HO. All patients maintained clinical and laboratory improvements 4 or 6 months after the RT. Our results suggest that RT is safe and effective in decreasing pain and activity of neurogenic HO.

  9. Clinical observation of taste disturbance induced by radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Yuzuru; Sera, Koshi; Nagasawa, Hiroshi; Fukushima, Noriyuki; Yajin, Koji; Harada, Yasuo (Hiroshima Univ. (Japan). School of Medicine)

    1984-02-01

    Qualitative gustometry (filter paper disc method) was performed in six patients who underwent radiation therapy. Following results were obtained. 1) Subjective taste disturbance appeared when irradiation dosage amounted to 1000-2000 rad. Whereas, it disappeared in 1 to 3 months after the termination of irradiation. 2) The longer the period of irradiation, the more slowly taste disturbance recovered. 3) Disgeusia was noticed in 44.3% of S, 66.7% of N, 70% of T and 36.2% of Q tests. 4) Taste thresholds in the apical tongue region improved almost parallel to subjective recovery of the taste. Occasionally taste disturbance was prolonged over a month. This is possibly due to delayed regeneration of the gustatory buds. Furthermore, conditions of the oral cavity, such as infection, or mechanical stimulation, may well influence degree of taste disturbance and the process of regeneration.

  10. Nanoparticles for Radiation Therapy Enhancement: the Key Parameters.

    Science.gov (United States)

    Retif, Paul; Pinel, Sophie; Toussaint, Magali; Frochot, Céline; Chouikrat, Rima; Bastogne, Thierry; Barberi-Heyob, Muriel

    2015-01-01

    This review focuses on the radiosensitization strategies that use high-Z nanoparticles. It does not establish an exhaustive list of the works in this field but rather propose constructive criticisms pointing out critical factors that could improve the nano-radiation therapy. Whereas most reviews show the chemists and/or biologists points of view, the present analysis is also seen through the prism of the medical physicist. In particular, we described and evaluated the influence of X-rays energy spectra using a numerical analysis. We observed a lack of standardization in preclinical studies that could partially explain the low number of translation to clinical applications for this innovative therapeutic strategy. Pointing out the critical parameters of high-Z nanoparticles radiosensitization, this review is expected to contribute to a larger preclinical and clinical development.

  11. Eddy current analysis and optimization of fast scanning magnet for a proton therapy system

    Science.gov (United States)

    Liu, Xu; Qin, Bin; Liu, Kaifeng; Chen, Wei; Liang, Zhikai; Chen, Qushan; Chen, Dezhi; Fan, Mingwu

    2017-08-01

    Proton therapy is now recognized as one of the most effective radiation therapy methods for cancers. A proton therapy facility with multiple gantry treatment rooms is under development in HUST (Huazhong University of Science and Technology), which is based on isochronous superconducting cyclotron scheme. In the beam line, the scanning system spreads out the proton beam on the target according to the complex tumour shape by two scanning magnets for horizontal and vertical scanning independently. Since these two magnets are excited by alternating currents and the maximum repetition frequency is up to 100 Hz, eddy currents and losses are expected to be significant. Slits are proven to be an effective way to reduce the eddy currents. To evaluate the heat distribution due to eddy losses in the pole end of the scanning magnet, the transient electromagnetic analysis and steady-state thermal analysis are performed. This paper describes design considerations of the scanning system and mainly analyses the eddy current effect of the scanning magnets. Different coil shapes and slit arrangements are simulated and compared to obtain the optimal configuration. The maximum temperatures of two magnets are optimized below 70 °C. In addition, the lag effect due to eddy currents is also discussed.

  12. Dosimetrically Triggered Adaptive Intensity Modulated Radiation Therapy for Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Karen [Department of Radiation Oncology, Liverpool Hospital, Sydney (Australia); Stewart, James [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario (Canada); Kelly, Valerie [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Xie, Jason [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Brock, Kristy K. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Moseley, Joanne [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Cho, Young-Bin; Fyles, Anthony [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Lundin, Anna; Rehbinder, Henrik; Löf, Johan [RaySearch Laboratories AB, Stockholm (Sweden); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Techna Institute for the Advancement of Technology for Health, Toronto, Ontario (Canada); Milosevic, Michael, E-mail: mike.milosevic@rmp.uhn.ca [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada)

    2014-09-01

    Purpose: The widespread use of intensity modulated radiation therapy (IMRT) for cervical cancer has been limited by internal target and normal tissue motion. Such motion increases the risk of underdosing the target, especially as planning margins are reduced in an effort to reduce toxicity. This study explored 2 adaptive strategies to mitigate this risk and proposes a new, automated method that minimizes replanning workload. Methods and Materials: Thirty patients with cervical cancer participated in a prospective clinical study and underwent pretreatment and weekly magnetic resonance (MR) scans over a 5-week course of daily external beam radiation therapy. Target volumes and organs at risk (OARs) were contoured on each of the scans. Deformable image registration was used to model the accumulated dose (the real dose delivered to the target and OARs) for 2 adaptive replanning scenarios that assumed a very small PTV margin of only 3 mm to account for setup and internal interfractional motion: (1) a preprogrammed, anatomy-driven midtreatment replan (A-IMRT); and (2) a dosimetry-triggered replan driven by target dose accumulation over time (D-IMRT). Results: Across all 30 patients, clinically relevant target dose thresholds failed for 8 patients (27%) if 3-mm margins were used without replanning. A-IMRT failed in only 3 patients and also yielded an additional small reduction in OAR doses at the cost of 30 replans. D-IMRT assured adequate target coverage in all patients, with only 23 replans in 16 patients. Conclusions: A novel, dosimetry-triggered adaptive IMRT strategy for patients with cervical cancer can minimize the risk of target underdosing in the setting of very small margins and substantial interfractional motion while minimizing programmatic workload and cost.

  13. Radiation Therapy for Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Gyu; Kim, Jin Hee; Byun, Sang Jun; Kim, Ok Bae; Hwang, Jae Seok; Oh, Young Kee; Choi, Tae Jin [Dongsan Medical Center, Keimyung University School of Medicine, Daegu (Korea, Republic of)

    2011-03-15

    To evaluate the effectiveness of radiation therapy (RT) for hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) and to analyze the prognostic factors. From December 2004 to April 2009, 70 patients who had HCC with PVTT were treated with RT at Keimyung University Dongsan Medical Center. Nineteen patients whose total dose was below 30 Gy and one patient who underwent liver transplantation were excluded. The remaining 50 patients (45 males, 5 females; median age 55 years) were analyzed. According to the LCSGJ TNM stage, there were 27 patients (54.0%) with stage III and 23 (46.0%) with stage IV. Total dose of 30-54 Gy was administered (median 45). Thirty patients (60.0%) were treated with concurrent chemoradiation therapy (CCRT). The median follow-up duration was from 13.5 months (range, 3 to 70 months). The median survival time from the start of RT was 9 months. One-year and 2-year overall survival rates were 24.9% and 11.2%, respectively. At the follow-up time, three patients (6.0%) displayed no evidence of disease. Seven patients (14.0%) were alive with disease, and 40 (80.0%) patients had expired due to disease progression. CCRT was associated with worse survival than RT alone (p=0.034). Response to RT (p=0.037), CLIP stage (p=0.017), and TNM stage (p=0.041) were statistically significant prognostic factors. There was no radiation-induced liver disease. RT is an effective and safe modality for HCC with PVTT. Further studies such as prospective randomized trials are needed to confirm the role of RT for HCC with PVTT.

  14. Proton-minibeam radiation therapy: A proof of concept

    Energy Technology Data Exchange (ETDEWEB)

    Prezado, Y. [IMNC-UMR 8165, CNRS, Paris 7 and Paris 11 Universities, 15 rue Georges Clemenceau, 91406 Orsay Cedex (France); Fois, G. R. [Dipartimento di Fisica, Universita degli Studi di Cagliari, Strada provinciale Monserrato Sestu km 0.700, Monserrato, Cagliari 09042 (Italy)

    2013-03-15

    Purpose: This Monte Carlo simulation work aims at studying a new radiotherapy approach called proton-minibeam radiation therapy (pMBRT). The main objective of this proof of concept was the evaluation of the possible gain in tissue sparing, thanks to the spatial fractionation of the dose, which could be used to deposit higher and potentially curative doses in clinical cases where tissue tolerances are a limit for conventional methods. Methods: Monte Carlo simulations (GATE v.6) have been used as a method to calculate the ratio of the peak-to-valley doses (PVDR) for arrays of proton minibeams of 0.7 mm width and several center-to-center distances, at different depths in a water phantom. The beam penumbras were also evaluated as an important parameter for tissue sparing, for example, in the treatment of non-cancer diseases like epilepsy. Two proton energies were considered in this study: a clinically relevant energy (105 MeV) and a very high energy (1 GeV), to benefit from a reduced lateral scattering. For the latter case, an interlaced geometry was also evaluated. Results: Higher or similar PVDR than the ones obtained in x-rays minibeam radiation therapy were achieved in several pMBRT configurations. In addition, for the two energies studied, the beam penumbras are smaller than in the case of Gamma Knife radiosurgery. Conclusions: The high PVDR obtained for some configurations and the small penumbras in comparison with existing radiosurgery techniques, suggest a potential gain in healthy tissue sparing in this new technique. Biological studies are warranted to assess the effects of pMBRT on both normal and tumoral tissues.

  15. Dynamic trajectory-based couch motion for improvement of radiation therapy trajectories in cranial SRT

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, R. Lee [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada); Thomas, Christopher G., E-mail: Chris.Thomas@cdha.nshealth.ca [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Medical Physics, Nova Scotia Cancer Centre, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia B3H 1V7 (Canada); Department of Radiation Oncology, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Radiology, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada)

    2015-05-15

    Purpose: To investigate potential improvement in external beam stereotactic radiation therapy plan quality for cranial cases using an optimized dynamic gantry and patient support couch motion trajectory, which could minimize exposure to sensitive healthy tissue. Methods: Anonymized patient anatomy and treatment plans of cranial cancer patients were used to quantify the geometric overlap between planning target volumes and organs-at-risk (OARs) based on their two-dimensional projection from source to a plane at isocenter as a function of gantry and couch angle. Published dose constraints were then used as weighting factors for the OARs to generate a map of couch-gantry coordinate space, indicating degree of overlap at each point in space. A couch-gantry collision space was generated by direct measurement on a linear accelerator and couch using an anthropomorphic solid-water phantom. A dynamic, fully customizable algorithm was written to generate a navigable ideal trajectory for the patient specific couch-gantry space. The advanced algorithm can be used to balance the implementation of absolute minimum values of overlap with the clinical practicality of large-scale couch motion and delivery time. Optimized cranial cancer treatment trajectories were compared to conventional treatment trajectories. Results: Comparison of optimized treatment trajectories with conventional treatment trajectories indicated an average decrease in mean dose to the OARs of 19% and an average decrease in maximum dose to the OARs of 12%. Degradation was seen for homogeneity index (6.14% ± 0.67%–5.48% ± 0.76%) and conformation number (0.82 ± 0.02–0.79 ± 0.02), but neither was statistically significant. Removal of OAR constraints from volumetric modulated arc therapy optimization reveals that reduction in dose to OARs is almost exclusively due to the optimized trajectory and not the OAR constraints. Conclusions: The authors’ study indicated that simultaneous couch and gantry motion

  16. DICOM and imaging informatics-based radiation therapy (RT) server

    Science.gov (United States)

    Law, Maria Y. Y.; Huang, H. K.; Zhang, Xiaoyan; Zhang, Jianguo

    2002-05-01

    Radiation therapy (RT) is an image intensive treatment. It requires images from projection X-rays, CT, MR, PET for tumor localization, treatment planning and verification of treatment plans. It also needs patient information, images and their processing for tumor localization and dose computation to ensure the delivery of uniform high dose to the target but avoidance of sensitive structures. In these processes, PACS and imaging informatics technologies are used extensively. However, they are not integrated with these technologies as a complete radiation treatment system. Currently RT treatment still relies mostly on tedious manual image and data transfer methods because the community as a whole has not championed the concept of system integration heavily. System integration of RT treatment has many benefits including lower equipment and operation costs, streamline treatment procedures, and better healthcare delivery to the patient. In this paper, we discuss the concept of a DICOM and imaging informatics-based RT server as an attempt to integrate diverse healthcare information systems, imaging modalities and RT equipment into one seamless treatment system.

  17. Stroke-like Migraine Attacks after Radiation Therapy Syndrome

    Directory of Open Access Journals (Sweden)

    Qian Zheng

    2015-01-01

    Full Text Available Objective: To summarize the clinical presentation, pathogenesis, neuroimaging, treatment, and outcome of stroke-like migraine attacks after radiation therapy (SMART syndrome, and to propose diagnostic criteria for this disorder. Data Sources: We searched the PubMed database for articles in English published from 1995 to 2015 using the terms of "stroke-like AND migraine AND radiation." Reference lists of the identified articles and reviews were used to retrieve additional articles. Study Selection: Data and articles related to late-onset effects of cerebral radiation were selected and reviewed. Results: SMART is a rare condition that involves complex migraines with focal neurologic deficits following cranial irradiation for central nervous system malignancies. The recovery, which ranges from hours to days to weeks, can be partial or complete. We propose the following diagnostic criteria for SMART: (1 Remote history of therapeutic external beam cranial irradiation for malignancy; (2 prolonged, reversible clinical manifestations mostly years after irradiation, which may include migraine, seizures, hemiparesis, hemisensory deficits, visuospatial defect, aphasia, confusion and so on; (3 reversible, transient, unilateral cortical gadolinium enhancement correlative abnormal T2 and fluid-attenuated inversion recovery signal of the affected cerebral region; (4 eventual complete or partial recovery, the length of duration of recovery ranging from hours to days to weeks; (5 no evidence of residual or recurrent tumor; (6 not attributable to another disease. To date, no specific treatment has been identified for this syndrome. Conclusions: SMART is an extremely rare delayed complication of brain irradiation. However, improvements in cancer survival rates have resulted in a rise in its frequency. Hence, awareness and recognition of the syndrome is important to make a rapid diagnosis and avoid aggressive interventions such as brain biopsy and cerebral

  18. Prevention of normal tissue complications in radiation therapy of head and neck cancer : the role of 3D conformal radiation therapy (3DCRT)

    NARCIS (Netherlands)

    O.B. Wijers (Oda)

    2002-01-01

    textabstractIn The Netherlands. head and neck cancer (3.9%) ranks the eighth most frequemly diagnoscd malignant tumor. Radiation therapy (IIT) plays an important role in the treatmem of patients with head and neck cancer, as they constitute approximately 6% of those treated in a routine radiation

  19. Stroke After Radiation Therapy for Head and Neck Cancer: What Is the Risk?

    Energy Technology Data Exchange (ETDEWEB)

    Arthurs, Erin [Department of Public Health Sciences, Queen' s University, Kingston, Ontario (Canada); Hanna, Timothy P. [Division of Cancer Care and Epidemiology, Queen' s University, Kingston, Ontario (Canada); Department of Oncology, Queen' s University, Kingston, Ontario (Canada); Zaza, Khaled [Department of Oncology, Queen' s University, Kingston, Ontario (Canada); Peng, Yingwei [Department of Public Health Sciences, Queen' s University, Kingston, Ontario (Canada); Hall, Stephen F., E-mail: sfh@queensu.ca [Division of Cancer Care and Epidemiology, Queen' s University, Kingston, Ontario (Canada); Department of Otolaryngology, Queen' s University, Kingston, Ontario (Canada)

    2016-11-01

    Purpose: A retrospective population-based cohort study was conducted to determine the risk of ischemic stroke with respect to time, associated with curative radiation therapy in head and neck squamous cell carcinomas (HNSCC). Methods and Materials: On the basis of data from the Ontario Cancer Registry and regional cancer treatment centers, 14,069 patients were identified with diagnoses of squamous cell carcinoma of the oral cavity, larynx, and pharynx who were treated for cure between 1990 and 2010. Hazards of stroke and time to stroke were examined, accounting for the competing risk of death. Stroke risk factors identified through diagnostic and procedural administrative codes were adjusted for in the comparison between treatment regimens, which included surgery alone versus radiation therapy alone and surgery alone versus any exposure to radiation therapy. Results: Overall, 6% of patients experienced an ischemic stroke after treatment, with 5% experiencing a stroke after surgery, 8% after radiation therapy alone, and 6% after any exposure to radiation therapy. The cause-specific hazard ratios of ischemic stroke after radiation therapy alone and after any exposure to radiation therapy compared with surgery were 1.70 (95% confidence interval [CI]: 1.41-2.05) and 1.46 (95% CI: 1.23-1.73), respectively, after adjustment for stroke risk factors, patient factors, and disease-related factors. Conclusions: Radiation therapy was associated with an increased risk of ischemic stroke compared with surgery alone: for both radiation therapy alone and after all treatment modalities that included any radiation treatment were combined. Because of a shift toward a younger HNSCC patient population, our results speak to the need for adequate follow-up and survivorship care among patients who have been treated with radiation therapy. Advances in treatment that minimize chronic morbidity also require further evaluation.

  20. Reducing rectal injury in men receiving prostate cancer radiation therapy: current perspectives

    Directory of Open Access Journals (Sweden)

    Serrano NA

    2017-07-01

    Full Text Available Nicholas A Serrano,1 Noah S Kalman,1 Mitchell S Anscher2 1Department of Radiation Oncology, Virginia Commonwealth University – Massey Cancer Center, Richmond, VA, 2Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA Abstract: Dose escalation is now the standard of care for the treatment of prostate cancer with radiation therapy. However, the rectum tends to be the dose-limiting structure when treating prostate cancer, given its close proximity. Early and late toxicities can occur when the rectum receives large doses of radiation therapy. New technologies allow for prevention of these toxicities. In this review, we examine the evidence that supports various dose constraints employed to prevent these rectal injuries from occurring. We also examine the use of intensity-modulated radiation therapy and how this compares to older radiation therapy techniques that allow for further sparing of the rectum during a radiation therapy course. We then review the literature on endorectal balloons and the effects of their daily use throughout a radiation therapy course. Tissue spacers are now being investigated in greater detail; these devices are injected into the rectoprostatic fascia to physically increase the distance between the prostate and the anterior rectal wall. Last, we review the use of systemic drugs, specifically statin medications and antihypertensives, as well as their impact on rectal toxicity. Keywords: rectal toxicity, radiation therapy, prostate, prevention 

  1. Molecular targeted treatment and radiation therapy for rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Marquardt, Friederike; Roedel, Franz; Capalbo, Gianni; Weiss, Christian; Roedel, Claus [Dept. of Radiation Therapy, Univ. of Frankfurt/Main (Germany)

    2009-06-15

    Background: EGFR (epidermal growth factor receptor) and VEGF (vascular endothelial growth factor) inhibitors confer clinical benefit in metastatic colorectal cancer when combined with chemotherapy. An emerging strategy to improve outcomes in rectal cancer is to integrate biologically active, targeted agents as triple therapy into chemoradiation protocols. Material and methods: cetuximab and bevacizumab have now been incorporated into phase I-II studies of preoperative chemoradiation therapy (CRT) for rectal cancer. The rationale of these combinations, early efficacy and toxicity data, and possible molecular predictors for tumor response are reviewed. Computerized bibliographic searches of Pubmed were supplemented with hand searches of reference lists and abstracts of ASCO and ASTRO meetings. Results: the combination of cetuximab and CRT can be safely applied without dose compromises of the respective treatment components. Disappointingly low rates of pathologic complete remission have been noted in several phase II studies. The K-ras mutation status and the gene copy number of EGFR may predict tumor response. The toxicity pattern (radiation-induced enteritis, perforations) and surgical complications (wound healing, fistula, bleeding) observed in at least some of the clinical studies with bevacizumab and CRT warrant further investigations. Conclusion: longer follow-up (and, finally, randomized trials) is needed to draw any firm conclusions with respect to local and distant failure rates, and toxicity associated with these novel treatment approaches. (orig.)

  2. Intraoperative radiation therapy (IORT) for adenocarcinoma of the pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Yasue, Mitsunori

    1988-04-01

    Between April 1980 and August 1987, a total of 54 patients with pancreatic adenocarcinoma were treated with intraoperative radiation therapy (IORT). Thirty-five patients underwent IORT with palliative intent (Group I), and the remaining 19 underwent it as an adjuvant therapy for pancreatectomy (Group II). The dosage of electron beams ranged from 12 to 30 Gy in Group I and from 20 to 30 Gy in Group II. Intractable back pain that was observed in 25 patients was relieved in 20 patients (80 %) within one week after IORT. The median survival was 5.3 months in Group I and 9.4 months in Group II. The longest survival (6 years and 10 months) was attained in a patient undergoing absolute non-curative distal pancreatectomy, followed by 20 Gy of IORT. In comparing patients treated before and after the introduction of IORT, both survival rate and staying-home survival rate were significantly better in the era of IORT during which background factors were rather worse. (Namekawa, K.).

  3. Cancer stem cells, cancer cell plasticity and radiation therapy.

    Science.gov (United States)

    Vlashi, Erina; Pajonk, Frank

    2015-04-01

    Since the first prospective identification of cancer stem cells in solid cancers the cancer stem cell hypothesis has reemerged as a research topic of increasing interest. It postulates that solid cancers are organized hierarchically with a small number of cancer stem cells driving tumor growth, repopulation after injury and metastasis. They give rise to differentiated progeny, which lack these features. The model predicts that for any therapy to provide cure, all cancer stem cells have to be eliminated while the survival of differentiated progeny is less critical. In this review we discuss recent reports challenging the idea of a unidirectional differentiation of cancer cells. These reports provide evidence supporting the idea that non-stem cancer cells exhibit a remarkable degree of plasticity that allows them to re-acquire cancer stem cell traits, especially in the context of radiation therapy. We summarize conditions under which differentiation is reversed and discuss the current knowledge of the underlying mechanisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The Role of Hypofractionated Radiation Therapy with Photons, Protons and Heavy Ions for Treating Extracranial Lesions

    Directory of Open Access Journals (Sweden)

    Aaron Michael Laine

    2016-01-01

    Full Text Available Traditionally, the ability to deliver large doses of ionizing radiation to a tumor has been limited by radiation induced toxicity to normal surrounding tissues. This was the initial impetus for the development of conventionally fractionated radiation therapy, where large volumes of healthy tissue received radiation and were allowed the time to repair the radiation damage. However, advances in radiation delivery techniques and image guidance have allowed for more ablative doses of radiation to be delivered in a very accurate, conformal and safe manner with shortened fractionation schemes. Hypofractionated regimens with photons have already transformed how certain tumor types are treated with radiation therapy. Additionally, hypofractionation is able to deliver a complete course of ablative radiation therapy over a shorter period of time compared to conventional fractionation regimens making treatment more convenient to the patient and potentially more cost-effective. Recently there has been an increased interest in proton therapy because of the potential further improvement in dose distributions achievable due to their unique physical characteristics. Furthermore, with heavier ions the dose conformality is increased and in addition there is potentially a higher biological effectiveness compared to protons and photons. Due to the properties mentioned above, charged particle therapy has already become an attractive modality to further investigate the role of hypofractionation in the treatment of various tumors. This review will discuss the rationale and evolution of hypofractionated radiation therapy, the reported clinical success with initially photon and then charged particle modalities, and further potential implementation into treatment regimens going forward.

  5. Dysuria Following Stereotactic Body Radiation Therapy for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Einsley-Marie eJanowski

    2015-07-01

    Full Text Available Background: Dysuria following prostate radiation therapy is a common toxicity that adversely affects patients’ quality of life and may be difficult to manage. Methods: 204 patients treated with stereotactic body radiation therapy (SBRT from 2007 to 2010 for localized prostate carcinoma with a minimum follow up of three years were included in this retrospective review of prospectively collected data. All patients were treated to 35-36.25Gy in 5 fractions delivered with robotic SBRT with real time fiducial tracking. Dysuria and other lower urinary tract symptoms were assessed via Question 4b (Pain or burning on urination of the Expanded Prostate Index Composite (EPIC-26 and the American Urological Association (AUA Symptom Score at baseline and at routine follow up. Results: 204 patients (82 low-, 105 intermediate-, and 17 high risk according to the D’Amico classification at a median age of 69 years (range 48-91 received SBRT for their localized prostate cancer with a median follow up of 47 months. Bother associated with dysuria significantly increased from a baseline of 12% to a maximum of 43% at one month (p<0.0001. There were two distinct peaks of moderate to severe dysuria bother at 1 month and at 6-12 months, with 9% of patients experiencing a late transient dysuria flare. While a low level of dysuria was seen through the first two years of follow-up, it returned to below baseline by two years (p=0.91. The median baseline AUA score of 7.5 significantly increased to 11 at 1 month (p<0.0001 and returned to 7 at 3 months (p= 0.54. Patients with dysuria had a statistically higher AUA score at baseline and at all follow-ups up to 30 months. Dysuria significantly correlated with dose and AUA score on multivariate analysis. Frequency and strain significantly correlated with dysuria on stepwise multivariate analysis.Conclusions: The rate and severity of dysuria following SBRT is comparable to patients treated with other radiation modalities.

  6. First reported treatment of aggressive hemangioma with intraoperative radiation therapy and kyphoplasty (Kypho-IORT

    Directory of Open Access Journals (Sweden)

    B. Pinar Sedeño

    2017-02-01

    Full Text Available Aggressive hemangiomas invade the spinal canal and/or paravertebral space and may cause cord compression and neurological symptoms. Radiation therapy was recognized as an effective strategy for the treatment of aggressive hemangiomas. Here, it is reported the first case of aggressive vertebral hemangioma treated by a combination of intraoperative radiation therapy and kyphoplasty (Kypho-IORT.

  7. Efficacy of six weeks infrared radiation therapy on chronic low back ...

    African Journals Online (AJOL)

    Background: Infrared radiation therapy is a modality widely used in Physiotherapy for the management of pain. The objective of this study was to determine the efficacy of six weeks infrared radiation therapy on pain intensity and functional disability index in subjects suffering from non- specific low back pain. Methods: The ...

  8. Ultraviolet B radiation therapy for psoriasis: Pursuing the optimal regime

    NARCIS (Netherlands)

    Matos, Tiago R.; Ling, Tsui C.; Sheth, Vaneeta

    2016-01-01

    Psoriasis is a chronic and common disease mediated by resident memory T cells that negatively affects a broad range of people worldwide. One of the oldest and most commonly used treatments is phototherapy. We reviewed the existing literature on the four main ultraviolet B (UVB) modalities of

  9. Sensitivity to plant modelling uncertainties in optimal feedback control of sound radiation from a panel

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    1997-01-01

    Optimal feedback control of broadband sound radiation from a rectangular baffled panel has been investigated through computer simulations. Special emphasis has been put on the sensitivity of the optimal feedback control to uncertainties in the modelling of the system under control.A model...... of a rectangular baffled panel radiating into free field has been constructed. Secondary actuators have been modelled as vibrational inputs acting directly on the panel. A cost function proportional to the averaged radiated sound power and based on knowledge of the modal amplitudes of the panel has been derived...... in terms of a set of radiation filters modelling the radiation dynamics.Linear quadratic feedback control applied to the panel in order to minimise the radiated sound power has then been simulated. The sensitivity of the model based controller to modelling uncertainties when using feedback from actual...

  10. Perspective in optimization of stem cell therapies for heart regeneration.

    Science.gov (United States)

    Gapska, Paulina; Kurpisz, Maciej

    2017-12-07

    There is a variety of mechanisms(s) factor(s) that may influence stem cell therapies for heart regeneration. Among the best candidates for stem cell source are: mesenchymal stem cells (also those isolated from adipose tissue), cardiac cell progenitors (CPC) and descendants of iPSC cells. iPSC/s can be potentially beneficial although their pluripotent induction has been still in question due to: low propagation efficacy, danger of genomic integration/instability, biological risk of current vector system teratoma formation etc. which have been discussed in this review. Optimization protocols are required in order to enhance stem cells resistance to pathological conditions that they may encounter in pathological organ and to increase their retention. Combination between gene transfer and stem cell therapy is now more often used in pre-clinical studies with the prospect of subsequent clinical trials. Complementary substances have been contemplated to support stem cell viability (mainly anti-inflammatory and anti- apoptotic agents), which have been tested in animal models with promising results. Integration of nanotechnology both for efficient stem cell imaging as well as with the aim to provide cell supporting scaffolds seem to be inevitable for further development of cellular therapies. The whole organ (heart) reconstruction as well as biodegradable scaffolds and scaffold-free cell sheets have been also outlined.

  11. [Uveitis associated with juvenile idiopathic arthritis : Optimization of immunomodulatory therapy].

    Science.gov (United States)

    Heiligenhaus, A; Tappeiner, C; Walscheid, K; Heinz, C

    2016-05-01

    Uveitis associated with juvenile idiopathic arthritis (JIA-associated uveitis) is a vision-threatening disorder with a high complication rate. Besides early diagnosis within screening programs an adequate therapy is essential for improvement of the long-term prognosis. Corticosteroid therapy is often insufficient. In addition to conventional immunosuppression, immunomodulatory drugs, so-called biologicals, are novel highly effective treatment modalities. A systematic search of the literature was carried out for biologicals currently used in the treatment of JIA-associated uveitis. Review of current publications, summary of treatment guidelines and discussion of treatment options for therapy refractive patients. In accordance with the current recommendations tumor necrosis factor (TNF) inhibitors are administered if uveitis inactivity cannot be achieved with topical corticosteroids and in the next stage with immunosuppressants (methotrexate preferred). According to the currently available data adalimumab is then preferred. When the effectiveness of TNF inhibitors ceases during long-term administration and/or recurrences, other biological response modifiers are attractive treatment options (e. g. lymphocyte inhibitors or specific receptor antagonists). The TNF inhibitors are of major importance for the treatment of JIA-associated uveitis. Prospective studies and registries would be desirable in order to be able to compare the value of TNF inhibitors and other biologicals and for optimization of treatment recommendations.

  12. Perspective in optimization of stem cell therapies for heart regeneration

    Directory of Open Access Journals (Sweden)

    Paulina Gapska

    2017-12-01

    Full Text Available There is a variety of mechanisms(s factor(s that may influence stem cell therapies for heart regeneration. Among the best candidates for stem cell source are: mesenchymal stem cells (also those isolated from adipose tissue, cardiac cell progenitors (CPC and descendants of iPSC cells. iPSC/s can be potentially beneficial although their pluripotent induction has been still in question due to: low propagation efficacy, danger of genomic integration/instability, biological risk of current vector system teratoma formation etc. which have been discussed in this review. Optimization protocols are required in order to enhance stem cells resistance to pathological conditions that they may encounter in pathological organ and to increase their retention. Combination between gene transfer and stem cell therapy is now more often used in pre-clinical studies with the prospect of subsequent clinical trials. Complementary substances have been contemplated to support stem cell viability (mainly anti-inflammatory and anti- apoptotic agents, which have been tested in animal models with promising results. Integration of nanotechnology both for efficient stem cell imaging as well as with the aim to provide cell supporting scaffolds seem to be inevitable for further development of cellular therapies. The whole organ (heart reconstruction as well as biodegradable scaffolds and scaffold-free cell sheets have been also outlined.

  13. SU-C-16A-06: Optimum Radiation Source for Radiation Therapy of Skin Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Safigholi, Habib [Science and Research Branch, Islamic Azad University, Fars, Persepolis (Iran, Islamic Republic of); Meigooni, A S. [Comprehensive cancer center of Nevada, Las Vegas, NV (United States); University of Nevada Las Vegas (UNLV), Las Vegas, NV (United States)

    2014-06-15

    Purpose: Recently, different applicators are designed for treatment of the skin cancer such as scalp and legs, using Ir-192 HDR Brachytherapy Sources (IR-HDRS), Miniature Electronic Brachytherapy Sources (MEBXS), and External Electron Beam Radiation Therapy (EEBRT). Although, all of these methodologies may deliver the desired radiation dose to the skin, the dose to the underlying bone may become the limiting factor for selection of the optimum treatment technique. In this project the radiation dose delivered to the underlying bone has been evaluated as a function of the radiation source and thickness of the underlying bone. Methods: MC simulations were performed using MCNP5 code. In these simulations, the mono-energetic and non-divergent photon beams of 30 keV, 50 keV, and 70 keV for MEBXS, 380 keV photons for IR-HDRS, and 6 MeV mono-energetic electron beam for EEBRT were modeled. A 0.5 cm thick soft tissue (0.3 cm skin and 0.2 cm adipose) with underlying 0.5 cm cortical bone followed by 14 cm soft tissue are utilized for simulations. Results: Dose values to bone tissue as a function of beam energy and beam type, for a delivery of 5000 cGy dose to skin, were compared. These results indicate that for delivery of 5000 cGy dose to the skin surface with 30 keV, 50 keV, 70 keV of MEBXS, IR-HDRS, and EEBRT techniques, bone will receive 31750 cGy, 27450 cGy, 18550 cGy, 4875 cGy, and 10450 cGy, respectively. Conclusion: The results of these investigations indicate that, for delivery of the same skin dose, average doses received by the underlying bone are 5.2 and 2.2 times larger with a 50 keV MEBXS and EEBRT techniques than IR-HDRS, respectively.

  14. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a {sup 60}Co Magnetic Resonance Image Guidance Radiation Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, H. Omar, E-mail: hwooten@radonc.wustl.edu; Green, Olga; Yang, Min; DeWees, Todd; Kashani, Rojano; Olsen, Jeff; Michalski, Jeff; Yang, Deshan; Tanderup, Kari; Hu, Yanle; Li, H. Harold; Mutic, Sasa

    2015-07-15

    Purpose: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating {sup 60}Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. Methods and Materials: The ViewRay treatment planning system (Oakwood Village, OH) was used to create {sup 60}Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The {sup 60}Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses and heterogeneity indices (HI) for planning target volumes (PTVs) and maximum, mean, and dose-volume histogram (DVH) values for OARs. Results: All {sup 60}Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for {sup 60}Co was within <1% and 3% of linac plans for 100% and 95% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range <20 Gy, but comparable sparing for organs with mean doses >20 Gy. The mean doses for all {sup 60}Co plan OARs were within clinical tolerances. Conclusions: A commercial {sup 60}Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system.

  15. Adaptive radiation therapy for postprostatectomy patients using real-time electromagnetic target motion tracking during external beam radiation therapy.

    Science.gov (United States)

    Zhu, Mingyao; Bharat, Shyam; Michalski, Jeff M; Gay, Hiram A; Hou, Wei-Hsien; Parikh, Parag J

    2013-03-15

    Using real-time electromagnetic (EM) transponder tracking data recorded by the Calypso 4D Localization System, we report inter- and intrafractional target motion of the prostate bed, describe a strategy to evaluate treatment adequacy in postprostatectomy patients receiving intensity modulated radiation therapy (IMRT), and propose an adaptive workflow. Tracking data recorded by Calypso EM transponders was analyzed for postprostatectomy patients that underwent step-and-shoot IMRT. Rigid target motion parameters during beam delivery were calculated from recorded transponder positions in 16 patients with rigid transponder geometry. The delivered doses to the clinical target volume (CTV) were estimated from the planned dose matrix and the target motion for the first 3, 5, 10, and all fractions. Treatment adequacy was determined by comparing the delivered minimum dose (Dmin) with the planned Dmin to the CTV. Treatments were considered adequate if the delivered CTV Dmin is at least 95% of the planned CTV Dmin. Translational target motion was minimal for all 16 patients (mean: 0.02 cm; range: -0.12 cm to 0.07 cm). Rotational motion was patient-specific, and maximum pitch, yaw, and roll were 12.2, 4.1, and 10.5°, respectively. We observed inadequate treatments in 5 patients. In these treatments, we observed greater target rotations along with large distances between the CTV centroid and transponder centroid. The treatment adequacy from the initial 10 fractions successfully predicted the overall adequacy in 4 of 5 inadequate treatments and 10 of 11 adequate treatments. Target rotational motion could cause underdosage to partial volume of the postprostatectomy targets. Our adaptive treatment strategy is applicable to post-prostatectomy patients receiving IMRT to evaluate and improve radiation therapy delivery. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Mometasone Furoate Cream Reduces Acute Radiation Dermatitis in Patients Receiving Breast Radiation Therapy: Results of a Randomized Trial

    Energy Technology Data Exchange (ETDEWEB)

    Hindley, Andrew, E-mail: andrew.hindley@lthtr.nhs.uk [Rosemere Cancer Centre, Royal Preston Hospital, Preston (United Kingdom); Zain, Zakiyah [College of Arts and Sciences, Universiti Utara Malaysia, Kedah (Malaysia); Wood, Lisa [Department of Social Sciences, Lancaster Medical School, Lancaster (United Kingdom); Whitehead, Anne [Medical and Pharmaceutical Statistics Research Unit, Lancaster University, Lancaster (United Kingdom); Sanneh, Alison; Barber, David; Hornsby, Ruth [Rosemere Cancer Centre, Royal Preston Hospital, Preston (United Kingdom)

    2014-11-15

    Purpose: We wanted to confirm the benefit of mometasone furoate (MF) in preventing acute radiation reactions, as shown in a previous study (Boström et al, Radiother Oncol 2001;59:257-265). Methods and Materials: The study was a double-blind comparison of MF with D (Diprobase), administered daily from the start of radiation therapy for 5 weeks in patients receiving breast radiation therapy, 40 Gy in 2.67-Gy fractions daily over 3 weeks. The primary endpoint was mean modified Radiation Therapy Oncology Group (RTOG) score. Results: Mean RTOG scores were significantly less for MF than for D (P=.046). Maximum RTOG and mean erythema scores were significantly less for MF than for D (P=.018 and P=.012, respectively). The Dermatology Life Quality Index (DLQI) score was significantly less for MF than for D at weeks 4 and 5 when corrected for Hospital Anxiety and Depression (HAD) questionnaire scores. Conclusions: MF cream significantly reduces radiation dermatitis when applied to the breast during and after radiation therapy. For the first time, we have shown a significantly beneficial effect on quality of life using a validated instrument (DLQI), for a topical steroid cream. We believe that application of this cream should be the standard of care where radiation dermatitis is expected.

  17. Applications of Cherenkov Light Emission for Dosimetry in Radiation Therapy

    Science.gov (United States)

    Glaser, Adam Kenneth

    Since its discovery in the 1930's, the Cherenkov effect has been paramount in the development of high-energy physics research. It results in light emission from charged particles traveling faster than the local speed of light in a dielectric medium. The ability of this emitted light to describe a charged particle's trajectory, energy, velocity, and mass has allowed scientists to study subatomic particles, detect neutrinos, and explore the properties of interstellar matter. However, only recently has the phenomenon been considered in the practical context of medical physics and radiation therapy dosimetry, where Cherenkov light is induced by clinical x-ray photon, electron, and proton beams. To investigate the relationship between this phenomenon and dose deposition, a Monte Carlo plug-in was developed within the Geant4 architecture for medically-oriented simulations (GAMOS) to simulate radiation-induced optical emission in biological media. Using this simulation framework, it was determined that Cherenkov light emission may be well suited for radiation dosimetry of clinically used x-ray photon beams. To advance this application, several novel techniques were implemented to realize the maximum potential of the signal, such as time-gating for maximizing the signal to noise ratio (SNR) and Cherenkov-excited fluorescence for generating isotropic light release in water. Proof of concept experiments were conducted in water tanks to demonstrate the feasibility of the proposed method for two-dimensional (2D) projection imaging, three-dimensional (3D) parallel beam tomography, large field of view 3D cone beam tomography, and video-rate dynamic imaging of treatment plans for a number of common radiotherapy applications. The proposed dosimetry method was found to have a number of unique advantages, including but not limited to its non-invasive nature, water-equivalence, speed, high-resolution, ability to provide full 3D data, and potential to yield data in-vivo. Based on

  18. A case of spontaneous pneumothorax following radiation therapy for non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Himanshu Bhardwaj

    2013-01-01

    Full Text Available Spontaneous pneumothorax (SPTX is a potentially devastating rare complication of the thoracic radiation therapy. Most of the cases in the medical literature, have been described in lymphoma patients receiving radiation therapy. The pathogenesis of this adverse event remains undefined although different mechanisms have been proposed. We present a case of post-radiation therapy SPTX in a non-small cell lung cancer (NSCLC, following intensity modulated radiation therapy (IMRT, which to our knowledge is the first such reported case related to this newer mode of radiation therapy. This report highlights the importance of keeping a close eye for this complication as timely treatment with chest tube insertion and drainage of the pneumothorax can be a lifesaving in these patients.

  19. Role of radiation therapy in the treatment of benign ocular diseases

    Directory of Open Access Journals (Sweden)

    Racheline

    1991-01-01

    Full Text Available Radiation therapy, although a prime treatment modality for malignant disease, has few definitive indications for some benign ocular diseases too. Orbital pseudotumour, Graves ophthalmopathy and pterygium are the conditions where the radiation oncologist has got an important role to play. This article reviews the current status of the role of radiation and its effectiveness in the management of these diseases.

  20. WE-D-BRD-01: Innovation in Radiation Therapy Delivery: Advanced Digital Linac Features

    Energy Technology Data Exchange (ETDEWEB)

    Xing, L [Stanford University, Stanford, CA (United States); Wong, J [Johns Hopkins University, Baltimore, MD (United States); Li, R [Stanford University, Palo Alto, CA (United States)

    2014-06-15

    Last few years has witnessed significant advances in linac technology and therapeutic dose delivery method. Digital linacs equipped with high dose rate FFF beams have been clinically implemented in a number of hospitals. Gated VMAT is becoming increasingly popular in treating tumors affected by respiratory motion. This session is devoted to update the audience with these technical advances and to present our experience in clinically implementing the new linacs and dose delivery methods. Topics to be covered include, technical features of new generation of linacs from different vendors, dosimetric characteristics and clinical need for FFF-beam based IMRT and VMAT, respiration-gated VMAT, the concept and implementation of station parameter optimized radiation therapy (SPORT), beam level imaging and onboard image guidance tools. Emphasis will be on providing fundamental understanding of the new treatment delivery and image guidance strategies, control systems, and the associated dosimetric characteristics. Commissioning and acceptance experience on these new treatment delivery technologies will be reported. Clinical experience and challenges encountered during the process of implementation of the new treatment techniques and future applications of the systems will also be highlighted. Learning Objectives: Present background knowledge of emerging digital linacs and summarize their key geometric and dosimetric features. SPORT as an emerging radiation therapy modality specifically designed to take advantage of digital linacs. Discuss issues related to the acceptance and commissioning of the digital linacs and FFF beams. Describe clinical utility of the new generation of digital linacs and their future applications.

  1. Comprehensive optimization of a heat pipe radiator assembly filled with ammonia or acetone

    Energy Technology Data Exchange (ETDEWEB)

    Vlassov, Valeri V.; De Sousa, Fabiano L.; Takahashi, Walter K. [National Institute for Space Research (INPE/DMC), Av. dos Astronautas, 1758. S.J.Campos, SP, 12227-010 (Brazil)

    2006-11-15

    Optimal mass characteristics for a heat pipe radiator assembly for space application are investigated. The assembly consists of the heat pipe itself, an evaporator saddle and a radiator. The internal HP geometry and the dimensions of the saddle and radiator panel are the variables to be optimized. Operational and structural constraints are considered and the assembly is optimized for different operational modes in 0g and 1g gravity conditions. A new global search metaheuristic, called generalized extremal optimization, was used as the optimization tool. The results show that under certain combinations of input parameters the assembly with acetone HP can be more weight effective than the one with ammonia, in spite of the liquid transport factor criterion indicates an opposite trend. (author)

  2. Use dibunol therapy for radiation injuries of the skin and mucous membranes

    Energy Technology Data Exchange (ETDEWEB)

    Agafonova, G.B.; Barsel' , V.A.; Sarkisyan, Yu.Kh.; Terekhova, G.S.; Podlyashchuk, E.L.; Ustinova, V.F. (Nauchno-Issledovatel' skij Inst. Rentgenologii i Radiologii, Moscow (USSR); AN SSSR, Moscow. Inst. Khimicheskoj Fiziki)

    1983-04-01

    There are presented the results of the use of dibunol in the form of liniment (1-10%) for the treatment of radiation cystitis and rectitis resulting from radiation therapy of small pelvic tumors, epidermitis and epithelitis that develop in the course of treatment of skin and lower lip tumors. A high efficacy of the drug in the therapy of radiation injury has been shown in 212 patients.

  3. WE-A-BRF-01: Dual-Energy CT Imaging in Diagnostic Imaging and Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Molloi, S [University of California, Irvine, CA (United States); Li, B [Boston University Medical Center, Boston, MA (United States); Yin, F [Duke University Medical Center, Durham, NC (United States); Chen, H [New York Presbyterian Hospital, New York, NY (United States)

    2014-06-15

    classification based on calcium scores shows excellent agreement with classification on the basis of conventional coronary artery calcium scoring. These studies demonstrate dual-energy cardiovascular CT can potentially be a noninvasive and sensitive modality in high risk patients. On-board KV/MV Imaging. To enhance soft tissue contrast and reduce metal artifacts, we have developed a dual-energy CBCT technique and a novel on-board kV/MV imaging technique based on hardware available on modern linear accelerators. We have also evaluated the feasibility of these two techniques in various phantom studies. Optimal techniques (energy, beam filtration, # of overlapping projections, etc) have been investigated with unique calibration procedures, which leads to successful decomposition of imaged material into acrylic-aluminum basis material pair. This enables the synthesis of virtual monochromatic (VM) CBCT images that demonstrate much less beam hardening, significantly reduced metal artifacts, and/or higher soft tissue CNR compared to single-energy CBCT. Adaptive Radiation Therapy. DECT could actually contribute to the area of Dose-Guided Radiation Therapy (or Adaptive Therapy). The application of DECT imaging using 80kV and 140 kV combinations could potentially increase the image quality by reducing the bone or high density material artifacts and also increase the soft tissue contrast by a light contrast agent. The result of this higher contrast / quality images is beneficial for deformable image registration / segmentation algorithm to improve its accuracy hence to make adaptive therapy less time consuming in its recontouring process. The real time re-planning prior to per treatment fraction could become more realistic with this improvement especially in hypofractional SBRT cases. Learning Objectives: Learn recent developments of dual-energy imaging in diagnosis and radiation therapy; Understand the unique clinical problem and required quantification accuracy in each application

  4. Comparison of acute and subacute genitourinary and gastrointestinal adverse events of radiotherapy for prostate cancer using intensity-modulated radiation therapy, three-dimensional conformal radiation therapy, permanent implant brachytherapy and high-dose-rate brachytherapy

    NARCIS (Netherlands)

    Morimoto, Masahiro; Yoshioka, Yasuo; Konishi, Koji; Isohashi, Fumiaki; Takahashi, Yutaka; Ogata, Toshiyuki; Koizumi, Masahiko; Teshima, Teruki; Bijl, Henk P; van der Schaaf, Arjen; Langendijk, Johannes A; Ogawa, Kazuhiko

    2014-01-01

    AIMS AND BACKGROUND: To examine acute and subacute urinary and rectal toxicity in patients with localized prostate cancer monotherapeutically treated with the following four radiotherapeutic techniques: intensity-modulated radiation therapy, three-dimensional conformal radiation therapy,

  5. Harnessing the Cancer Radiation Therapy by Lanthanide-Doped Zinc Oxide Based Theranostic Nanoparticles.

    Science.gov (United States)

    Ghaemi, Behnaz; Mashinchian, Omid; Mousavi, Tayebeh; Karimi, Roya; Kharrazi, Sharmin; Amani, Amir

    2016-02-10

    In this paper, doping of europium (Eu) and gadolinium (Gd) as high-Z elements into zinc oxide (ZnO) nanoparticles (NPs) was designed to optimize restricted energy absorption from a conventional radiation therapy by X-ray. Gd/Eu-doped ZnO NPs with a size of 9 nm were synthesized by a chemical precipitation method. The cytotoxic effects of Eu/Gd-doped ZnO NPs were determined using MTT assay in L929, HeLa, and PC3 cell lines under dark conditions as well as exposure to ultraviolet, X-ray, and γ radiation. Doped NPs at 20 μg/mL concentration under an X-ray dose of 2 Gy were as efficient as 6 Gy X-ray radiation on untreated cells. It is thus suggested that the doped NPs may be used as photoinducers to increase the efficacy of X-rays within the cells, consequently, cancer cell death. The doped NPs also could reduce the received dose by normal cells around the tumor. Additionally, we evaluated the diagnostic efficacy of doped NPs as CT/MRI nanoprobes. Results showed an efficient theranostic nanoparticulate system for simultaneous CT/MR imaging and cancer treatment.

  6. Nominal effective radiation doses delivered during clinical trials of boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Capala, J.; Diaz, A.Z.; Chanana, A.D.

    1997-12-31

    Boron neutron capture therapy (BNCT) is a binary system that, in theory, should selectively deliver lethal, high linear energy transfer (LET) radiation to tumor cells dispersed within normal tissues. It is based on the nuclear reaction 10-B(n, {alpha})7-Li, which occurs when the stable nucleus of boron-10 captures a thermal neutron. Due to the relatively high cross-section of the 10-B nucleus for thermal neutron capture and short ranges of the products of this reaction, tumor cells in the volume exposed to thermal neutrons and containing sufficiently high concentration of 10-B would receive a much higher radiation dose than the normal cells contained within the exposed volume. Nevertheless, radiation dose deposited in normal tissue by gamma and fast neutron contamination of the neutron beam, as well as neutron capture in nitrogen, 14-N(n,p)14-C, hydrogen, 1-H(n,{gamma})2-H, and in boron present in blood and normal cells, limits the dose that can be delivered to tumor cells. It is, therefore, imperative for the success of the BNCT the dosed delivered to normal tissues be accurately determined in order to optimize the irradiation geometry and to limit the volume of normal tissue exposed to thermal neutrons. These are the major objectives of BNCT treatment planning.

  7. Predictors of urinary and rectal toxicity after external conformed radiation therapy in prostate cancer: Correlation between clinical, tumour and dosimetric parameters and radical and postoperative radiation therapy.

    Science.gov (United States)

    Martínez-Arribas, C M; González-San Segundo, C; Cuesta-Álvaro, P; Calvo-Manuel, F A

    2017-06-15

    To determine rectal and urinary toxicity after external beam radiation therapy (EBRT), assessing the results of patients who undergo radical or postoperative therapy for prostate cancer (pancreatic cancer) and their correlation with potential risk factors. A total of 333 patients were treated with EBRT. Of these, 285 underwent radical therapy and 48 underwent postoperative therapy (39 cases of rescue and 9 of adjuvant therapy). We collected clinical, tumour and dosimetric variable to correlate with toxicity parameters. We developed decision trees based on the degree of statistical significance. The rate of severe acute toxicity, both urinary and rectal, was 5.4% and 1.5%, respectively. The rate of chronic toxicity was 4.5% and 2.7%, respectively. Twenty-seven patients presented haematuria, and 9 presented haemorrhagic rectitis. Twenty-five patients (7.5%) presented permanent limiting sequela. The patients with lower urinary tract symptoms prior to the radiation therapy presented poorer tolerance, with greater acute bladder toxicity (P=0.041). In terms of acute rectal toxicity, 63% of the patients with mean rectal doses >45Gy and anticoagulant/antiplatelet therapy developed mild toxicity compared with 37% of the patients with mean rectal doses <45 Gy and without anticoagulant therapy. We were unable to establish predictors of chronic toxicity in the multivariate analysis. The long-term sequelae were greater in the patients who underwent urological operations prior to the radiation therapy and who were undergoing anticoagulant therapy. The tolerance to EBRT was good, and severe toxicity was uncommon. Baseline urinary symptoms constitute the predictor that most influenced the acute urinary toxicity. Rectal toxicity is related to the mean rectal dose and with anticoagulant/antiplatelet therapy. There were no significant differences in severe toxicity between radical versus postoperative radiation therapy. Copyright © 2017 AEU. Publicado por Elsevier España, S

  8. A challenge for theranostics: is the optimal particle for therapy also optimal for diagnostics?

    Science.gov (United States)

    Dreifuss, Tamar; Betzer, Oshra; Shilo, Malka; Popovtzer, Aron; Motiei, Menachem; Popovtzer, Rachela

    2015-09-01

    Theranostics is defined as the combination of therapeutic and diagnostic capabilities in the same agent. Nanotechnology is emerging as an efficient platform for theranostics, since nanoparticle-based contrast agents are powerful tools for enhancing in vivo imaging, while therapeutic nanoparticles may overcome several limitations of conventional drug delivery systems. Theranostic nanoparticles have drawn particular interest in cancer treatment, as they offer significant advantages over both common imaging contrast agents and chemotherapeutic drugs. However, the development of platforms for theranostic applications raises critical questions; is the optimal particle for therapy also the optimal particle for diagnostics? Are the specific characteristics needed to optimize diagnostic imaging parallel to those required for treatment applications? This issue is examined in the present study, by investigating the effect of the gold nanoparticle (GNP) size on tumor uptake and tumor imaging. A series of anti-epidermal growth factor receptor conjugated GNPs of different sizes (diameter range: 20-120 nm) was synthesized, and then their uptake by human squamous cell carcinoma head and neck cancer cells, in vitro and in vivo, as well as their tumor visualization capabilities were evaluated using CT. The results showed that the size of the nanoparticle plays an instrumental role in determining its potential activity in vivo. Interestingly, we found that although the highest tumor uptake was obtained with 20 nm C225-GNPs, the highest contrast enhancement in the tumor was obtained with 50 nm C225-GNPs, thus leading to the conclusion that the optimal particle size for drug delivery is not necessarily optimal for imaging. These findings stress the importance of the investigation and design of optimal nanoparticles for theranostic applications.Theranostics is defined as the combination of therapeutic and diagnostic capabilities in the same agent. Nanotechnology is emerging as an

  9. Theoretical dosimetric evaluation of carbon and oxygen minibeam radiation therapy.

    Science.gov (United States)

    González, Wilfredo; Peucelle, Cécile; Prezado, Yolanda

    2017-05-01

    Charged particles have several advantages over x-ray radiations, both in terms of physics and radiobiology. The combination of these advantages with those of minibeam radiation therapy (MBRT) could help enhancing the therapeutic index for some cancers with poor prognosis. Among the different ions explored for therapy, carbon ions are considered to provide the optimum physical and biological characteristics. Oxygen could be advantageous due to a reduced oxygen enhancement ratio along with a still moderate biological entrance dose. The aforementioned reasons justified an in-depth evaluation of the dosimetric features of carbon and oxygen minibeam radiation therapy to establish the interest of further explorations of this avenue. The GATE/Geant4 6.2 Monte Carlo simulation platform was employed to simulate arrays of rectangular carbon and oxygen minibeams (600 μm × 2 cm) at a water phantom entrance. They were assumed to be generated by means of a magnetic focusing. The irradiations were performed with a 2-cm-long spread-out Bragg peak (SOBP) centered at 7-cm-depth. Several center-to-center (c-t-c) distances were considered. Peak and valley doses, as well as peak-to-valley dose ratio (PVDR) and the relative contribution of nuclear fragments and electromagnetic processes were assessed. In addition, the type and proportion of the secondary nuclear fragments were evaluated in both peak and valley regions. Carbon and oxygen MBRT lead to very similar dose distributions. No significant advantage of oxygen over carbon ions was observed from physical point of view. Favorable dosimetric features were observed for both ions. Thanks to the reduced lateral scattering, the standard shape of the depth dose curves (in the peaks) is maintained even for submillimetric beam sizes. When a narrow c-t-c is considered (910-980 μm), a (quasi) homogenization of the dose can be obtained at the target, while a spatial fractionation of the dose is maintained in the proximal normal tissues with

  10. Managing Radiation Therapy Side Effects: What to Do about Feeling Sick to Your Stomach and Throwing Up (Nausea and ...

    Science.gov (United States)

    ... Radiation Therapy Side Effects What To Do About Feeling Sick to Your Stomach and Throwing Up (Nausea ... you eat it. Managing Radiation Therapy Side Effects: Feeling Sick to Your Stomach and Throwing Up (Nausea ...

  11. [Prognostic factors of hyperbaric oxygen therapy in hemorrhagic radiation cystitis].

    Science.gov (United States)

    Bouaziz, M; Genestal, M; Perez, G; Bou-Nasr, E; Latorzeff, I; Thoulouzan, M; Game, X; Soulie, M; Beauval, J-B; Huyghe, E

    2017-01-01

    To emphasize prognostic factors of hyperbaric oxygen therapy (HBOT) on hematuria at 3 and 12 months in the context of a radiation cystitis. A cohort of 134 patients was treated from 2008 to 2013 in the hyperbaric medicine center of Toulouse University Hospital, France for radiation cystitis. Hematuria was ranked using the SOMA score. HBOT has been applied according to a standardized protocol of 20 renewable sessions, with pure oxygen to 2.5 ATA. The median number of sessions at 12 months was 50. HBOT had an efficacy of 83% at 3 months and 81% at 12 months. Twenty percent of patients had minor side effects. Compared to the pre-HBOT period, the number of hospitalizations decreased by 75% following treatment. The efficacy at 3 months was predictive of efficacy at 12 months (P<0.0001). There was an inverse correlation between the initial grade and efficacy at 3 months (P=0.026) and 12 months (P=0.001). A high WHO status diminished HBOT efficacy at 3 and 12 months (P=0.0014 and P<0.0001, respectively). An anticoagulant intake decreased the HBOT response at 12 months (P=0.002). Other parameters had no effects on efficacy. The efficacy at 3 months seems to be predictive of efficacy at 12 months. The initial hematuria grade is inversely correlated with efficacy at 3 and 12 months. It appears necessary to achieve at least 32 HBOT sessions. Moreover, a high WHO status and an anticoagulant intake seem to have a negative prognostic value. 4. Copyright © 2016. Published by Elsevier Masson SAS.

  12. Proton Radiation Therapy for the Treatment of Retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Mouw, Kent W. [Harvard Radiation Oncology Program, Boston, Massachusetts (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Sethi, Roshan V.; Yeap, Beow Y.; MacDonald, Shannon M.; Chen, Yen-Lin E.; Tarbell, Nancy J.; Yock, Torunn I.; Munzenrider, John E.; Adams, Judith [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Grabowski, Eric [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); Mukai, Shizuo [Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2014-11-15

    Purpose: To investigate long-term disease and toxicity outcomes for pediatric retinoblastoma patients treated with proton radiation therapy (PRT). Methods and Materials: This is a retrospective analysis of 49 retinoblastoma patients (60 eyes) treated with PRT between 1986 and 2012. Results: The majority (84%) of patients had bilateral disease, and nearly half (45%) had received prior chemotherapy. At a median follow-up of 8 years (range, 1-24 years), no patients died of retinoblastoma or developed metastatic disease. The post-PRT enucleation rate was low (18%), especially in patients with early-stage disease (11% for patients with International Classification for Intraocular Retinoblastoma [ICIR] stage A-B disease vs 23% for patients with ICIR stage C-D disease). Post-PRT ophthalmologic follow-up was available for 61% of the preserved eyes (30 of 49): 14 of 30 eyes (47%) had 20/40 visual acuity or better, 7 of 30 (23%) had moderate visual acuity (20/40-20/600), and 9 of 30 (30%) had little or no useful vision (worse than 20/600). Twelve of 60 treated eyes (20%) experienced a post-PRT event requiring intervention, with cataracts the most common (4 eyes). No patients developed an in-field second malignancy. Conclusions: Long-term follow-up of retinoblastoma patients treated with PRT demonstrates that PRT can achieve high local control rates, even in advanced cases, and many patients retain useful vision in the treated eye. Treatment-related ocular side effects were uncommon, and no radiation-associated malignancies were observed.

  13. Radiation therapy and androgen deprivation in the management of high risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Alan Dal Pra

    2011-04-01

    Full Text Available The combined use of radiation therapy (RT and androgen deprivation for patients with localized high-risk prostate cancer is commonly accepted as the standard treatment among uro-oncologists. Preclinical studies have provided rationale for the use of this combination. Additionally, results of phase 3 studies using conventional doses of RT have supported the combined approach. Other phase 3 studies have also shown a benefit for using higher doses of RT; however, the role of androgen deprivation in this context is not clear. The optimal duration of the androgen deprivation, in both the neoadjuvant and adjuvant setting, is still under investigation. This article critically reviews the data on the use of RT combined with androgen deprivation for the treatment of high-risk prostate cancer with emphasis on the results of phase 3 trials.

  14. A Study of Pseudoprogression After Spine Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bahig, Houda; Simard, Dany [Department of Radiation Oncology, Centre Hospitalier de l' Université de Montréal, Montreal, Quebec (Canada); Létourneau, Laurent [Department of Radiology, Centre Hospitalier de l' Université de Montréal, Montreal, Quebec (Canada); Wong, Philip; Roberge, David; Filion, Edith; Donath, David [Department of Radiation Oncology, Centre Hospitalier de l' Université de Montréal, Montreal, Quebec (Canada); Sahgal, Arjun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Masucci, Laura, E-mail: g.laura.masucci.chum@ssss.gouv.qc.ca [Department of Radiation Oncology, Centre Hospitalier de l' Université de Montréal, Montreal, Quebec (Canada)

    2016-11-15

    Purpose: To determine the incidence of pseudoprogression (PP) after spine stereotactic body radiation therapy based on a detailed and quantitative assessment of magnetic resonance imaging (MRI) morphologic tumor alterations, and to identify predictive factors distinguishing PP from local recurrence (LR). Methods and Materials: A retrospective analysis of 35 patients with 49 spinal segments treated with spine stereotactic body radiation therapy, from 2009 to 2014, was conducted. The median number of follow-up MRI studies was 4 (range, 2-7). The gross tumor volumes (GTVs) within each of the 49 spinal segments were contoured on the pretreatment and each subsequent follow-up T1- and T2-weighted MRI sagittal sequence. T2 signal intensity was reported as the mean intensity of voxels constituting each volume. LR was defined as persistent GTV enlargement on ≥2 serial MRI studies for ≥6 months or on pathologic confirmation. PP was defined as a GTV enlargement followed by stability or regression on subsequent imaging within 6 months. Kaplan-Meier analysis was used for estimation of actuarial local control, disease-free survival, and overall survival. Results: The median follow-up was 23 months (range, 1-39 months). PP was identified in 18% of treated segments (9 of 49) and LR in 29% (14 of 49). Earlier volume enlargement (5 months for PP vs 15 months for LR, P=.005), greater GTV to reference nonirradiated vertebral body T2 intensity ratio (+30% for PP vs −10% for LR, P=.005), and growth confined to 80% of the prescription isodose line (80% IDL) (8 of 9 PP cases vs 1 of 14 LR cases, P=.002) were associated with PP on univariate analysis. Multivariate analysis confirmed an earlier time to volume enlargement and growth within the 80% IDL as significant predictors of PP. LR involved the epidural space in all but 1 lesion, whereas PP was confined to the vertebral body in 7 of 9 cases. Conclusions: PP was observed in 18% of treated spinal segments. Tumor growth

  15. Image-guided radiation therapy for treatment delivery and verification

    Science.gov (United States)

    Schubert, Leah Kayomi

    Target conformity and normal tissue sparing provided by modern radiation therapy techniques often result in steep dose gradients, which increase the need for more accurate patient setup and treatment delivery. Image guidance is starting to play a major role in determining the accuracy of treatment setup. A typical objective of image-guided radiation therapy (IGRT) is to minimize differences between planned and delivered treatment by imaging the patient prior to delivery. This step verifies and corrects for patient setup and is referred to as setup verification. This dissertation evaluates the efficacy of daily imaging for setup verification and investigates new uses of IGRT for potential improvements in treatment delivery. The necessity of daily imaging can first be determined by assessing differences in setup corrections between patient groups. Therefore, the first objective of this investigation was to evaluate the application of IGRT for setup verification by quantifying differences in patient positioning for several anatomical disease sites. Detailed analysis of setup corrections for brain, head and neck, lung, and prostate treatments is presented. In this analysis, large setup errors were observed for prostate treatments. Further assessment of prostate treatments was performed, and patient-specific causes of setup errors investigated. Setup corrections are applied via rigid shifts or rotations of the patient or machine, but anatomical deformations occur for which rigid shifts cannot correct. Fortunately, IGRT provides images on which anatomical changes occurring throughout the course of treatment can be detected. From those images, the efficacy of IGRT in ensuring accurate treatment delivery can be evaluated and improved by determining delivered doses and adapting the plan during treatment. The second objective of this dissertation was to explore new applications of IGRT to further improve treatment. By utilizing daily IGRT images, a retrospective analysis of

  16. Estimated radiation pneumonitis risk after photon versus proton therapy alone or combined with chemotherapy for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Vogelius, Ivan R.; Aznar, Marianne C. (Radiation Medicine Research Center, Dept. of Radiation Oncology, Rigshospitalet, Copenhagen Univ. Hospital (Denmark)), e-mail: vogelius@gmail.com; Westerly, David C.; Cannon, George M.; Mackie, Thomas R.; Bentzen, Soeren M. (Dept. of Human Oncology, Univ. of Wisconsin School of Medicine and Public Health, Madison (United States)); Korreman, Stine S. (Radiation Medicine Research Center, Dept. of Radiation Oncology, Rigshospitalet, Copenhagen Univ. Hospital (Denmark); Dept. of Science, Systems and Models, Roskilde Univ., Roskilde (Denmark)); Mehta, Minesh P. (Northwestern Univ., Feinberg School of Medicine, Chicago (United States))

    2011-08-15

    Background. Traditionally, radiation therapy plans are optimized without consideration of chemotherapy. Here, we model the risk of radiation pneumonitis (RP) in the presence of a possible interaction between chemotherapy and radiation dose distribution. Material and methods. Three alternative treatment plans are compared in 18 non-small cell lung cancer patients previously treated with helical tomotherapy; the tomotherapy plan, an intensity modulated proton therapy plan (IMPT) and a three dimensional conformal radiotherapy (3D-CRT) plan. All plans are optimized without consideration of the chemotherapy effect. The effect of chemotherapy is modeled as an independent cell killing process using a uniform chemotherapy equivalent radiation dose (CERD) added to the entire organ at risk. We estimate the risk of grade 3 or higher RP (G3RP) using the critical volume model. Results. The mean risk of clinical G3RP at zero CERD is 5% for tomotherapy (range: 1-18 %) and 14% for 3D-CRT (range 2-49%). When the CERD exceeds 9 Gy, however, the risk of RP with the tomotherapy plans become higher than the 3D-CRT plans. The IMPT plans are less toxic both at zero CERD (mean 2%, range 1-5%) and at CERD = 10 Gy (mean 7%, range 1-28%). Tomotherapy yields a lower risk of RP than 3D-CRT for 17/18 patients at zero CERD, but only for 7/18 patients at CERD = 10 Gy. IMPT gives the lowest risk of all plans for 17/18 patients at zero CERD and for all patients with CERD = 10 Gy. Conclusions. The low dose bath from highly conformal photon techniques may become relevant for lung toxicity when radiation is combined with cytotoxic chemotherapy as shown here. Proton therapy allows highly conformal delivery while minimizing the low dose bath potentially interacting with chemotherapy. Thus, intensive drug-radiation combinations could be an interesting indication for selecting patients for proton therapy. It is likely that the IMRT plans would perform better if the CERD was accounted for during

  17. Optimal antiviral switching to minimize resistance risk in HIV therapy.

    Directory of Open Access Journals (Sweden)

    Rutao Luo

    Full Text Available The development of resistant strains of HIV is the most significant barrier to effective long-term treatment of HIV infection. The most common causes of resistance development are patient noncompliance and pre-existence of resistant strains. In this paper, methods of antiviral regimen switching are developed that minimize the risk of pre-existing resistant virus emerging during therapy switches necessitated by virological failure. Two distinct cases are considered; a single previous virological failure and multiple virological failures. These methods use optimal control approaches on experimentally verified mathematical models of HIV strain competition and statistical models of resistance risk. It is shown that, theoretically, order-of-magnitude reduction in risk can be achieved, and multiple previous virological failures enable greater success of these methods in reducing the risk of subsequent treatment failures.

  18. Allogeneic cell therapy bioprocess economics and optimization: downstream processing decisions.

    Science.gov (United States)

    Hassan, Sally; Simaria, Ana S; Varadaraju, Hemanthram; Gupta, Siddharth; Warren, Kim; Farid, Suzanne S

    2015-01-01

    To develop a decisional tool to identify the most cost effective process flowsheets for allogeneic cell therapies across a range of production scales. A bioprocess economics and optimization tool was built to assess competing cell expansion and downstream processing (DSP) technologies. Tangential flow filtration was generally more cost-effective for the lower cells/lot achieved in planar technologies and fluidized bed centrifugation became the only feasible option for handling large bioreactor outputs. DSP bottlenecks were observed at large commercial lot sizes requiring multiple large bioreactors. The DSP contribution to the cost of goods/dose ranged between 20-55%, and 50-80% for planar and bioreactor flowsheets, respectively. This analysis can facilitate early decision-making during process development.

  19. Radiobiological mechanisms of stereotactic body radiation therapy and stereotactic radiation surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Sook; Kim, Won Woo; Park, In Hwan; Kim, Hee Jong; Lee, Eun Jin; Jung, Jae Hoon [Research Center for Radiotherapy, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Cho, Lawrence Chin Soo; Song, Chang W. [Dept. of Radiation Oncology, University of Minnesota Medical School, Minneapolis (United States)

    2015-12-15

    Despite the increasing use of stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS) in recent years, the biological base of these high-dose hypo-fractionated radiotherapy modalities has been elusive. Given that most human tumors contain radioresistant hypoxic tumor cells, the radiobiological principles for the conventional multiple-fractionated radiotherapy cannot account for the high efficacy of SBRT and SRS. Recent emerging evidence strongly indicates that SBRT and SRS not only directly kill tumor cells, but also destroy the tumor vascular beds, thereby deteriorating intratumor microenvironment leading to indirect tumor cell death. Furthermore, indications are that the massive release of tumor antigens from the tumor cells directly and indirectly killed by SBRT and SRS stimulate anti-tumor immunity, thereby suppressing recurrence and metastatic tumor growth. The reoxygenation, repair, repopulation, and redistribution, which are important components in the response of tumors to conventional fractionated radiotherapy, play relatively little role in SBRT and SRS. The linear-quadratic model, which accounts for only direct cell death has been suggested to overestimate the cell death by high dose per fraction irradiation. However, the model may in some clinical cases incidentally do not overestimate total cell death because high-dose irradiation causes additional cell death through indirect mechanisms. For the improvement of the efficacy of SBRT and SRS, further investigation is warranted to gain detailed insights into the mechanisms underlying the SBRT and SRS.

  20. A comprehensive dosimetric study of pancreatic cancer treatment using three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated radiation therapy (VMAT), and passive-scattering and modulated-scanning