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Sample records for therapy treatment planning

  1. Treatment planning optimisation in proton therapy

    Science.gov (United States)

    McGowan, S E; Burnet, N G; Lomax, A J

    2013-01-01

    ABSTRACT. The goal of radiotherapy is to achieve uniform target coverage while sparing normal tissue. In proton therapy, the same sources of geometric uncertainty are present as in conventional radiotherapy. However, an important and fundamental difference in proton therapy is that protons have a finite range, highly dependent on the electron density of the material they are traversing, resulting in a steep dose gradient at the distal edge of the Bragg peak. Therefore, an accurate knowledge of the sources and magnitudes of the uncertainties affecting the proton range is essential for producing plans which are robust to these uncertainties. This review describes the current knowledge of the geometric uncertainties and discusses their impact on proton dose plans. The need for patient-specific validation is essential and in cases of complex intensity-modulated proton therapy plans the use of a planning target volume (PTV) may fail to ensure coverage of the target. In cases where a PTV cannot be used, other methods of quantifying plan quality have been investigated. A promising option is to incorporate uncertainties directly into the optimisation algorithm. A further development is the inclusion of robustness into a multicriteria optimisation framework, allowing a multi-objective Pareto optimisation function to balance robustness and conformity. The question remains as to whether adaptive therapy can become an integral part of a proton therapy, to allow re-optimisation during the course of a patient's treatment. The challenge of ensuring that plans are robust to range uncertainties in proton therapy remains, although these methods can provide practical solutions. PMID:23255545

  2. 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

  3. SERA - An Advanced Treatment Planning System for Neutron Therapy

    Energy Technology Data Exchange (ETDEWEB)

    C. A. Wemple; C. L. Albright; D. W. Nigg; D. W. Wessol; F. J. Wheeler; G. J. Harkin; M. B. Rossmeirer; M. T. Cohen; M. W. Frandsen

    1999-06-01

    The technology for computational dosimetry and treatment planning for Boron Neutron Capture Therapy (BNCT) has advanced significantly over the past few years. Because of the more complex nature of the problem, the computational methods that work well for treatment planning in photon radiotherapy are not applicable to BNCT. The necessary methods have, however, been developed and have been successfully employed both for research applications as well as human trials. Computational geometry for BNCT applications can be constructed directly from tomographic medical imagery and computed radiation dose distributions can be readily displayed in formats that are familiar to the radiotherapy community. The SERA system represents a significant advance in several areas for treatment planning. However further improvements in speed and results presentation are still needed for routine clinical applications, particularly when optimizations of dose pattern is required.

  4. 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

  5. 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...

  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. 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.

  8. Investigating the robustness of ion beam therapy treatment plans to uncertainties in biological treatment parameters

    CERN Document Server

    Boehlen, T T; Dosanjh, M; Ferrari, A; Fossati, P; Haberer, T; Mairani, A; Patera, V

    2012-01-01

    Uncertainties in determining clinically used relative biological effectiveness (RBE) values for ion beam therapy carry the risk of absolute and relative misestimations of RBE-weighted doses for clinical scenarios. This study assesses the consequences of hypothetical misestimations of input parameters to the RBE modelling for carbon ion treatment plans by a variational approach. The impact of the variations on resulting cell survival and RBE values is evaluated as a function of the remaining ion range. In addition, the sensitivity to misestimations in RBE modelling is compared for single fields and two opposed fields using differing optimization criteria. It is demonstrated for single treatment fields that moderate variations (up to +/-50\\%) of representative nominal input parameters for four tumours result mainly in a misestimation of the RBE-weighted dose in the planning target volume (PTV) by a constant factor and only smaller RBE-weighted dose gradients. Ensuring a more uniform radiation quality in the PTV...

  9. Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning

    OpenAIRE

    Paulus, Daniel H.; Thorwath, Daniela; Schmidt, Holger; Quick, Harald H.

    2014-01-01

    Purpose: Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning d...

  10. 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.

  11. Improving proton therapy accessibility through seamless electronic integration of remote treatment planning sites.

    Science.gov (United States)

    Belard, Arnaud; Dolney, Derek; Zelig, Tochner; McDonough, James; O'Connell, John

    2011-06-01

    Proton radiotherapy is a relatively scarce treatment modality in radiation oncology, with only nine centers currently operating in the United States. Funded by Public Law 107-248, the University of Pennsylvania and the Walter Reed Army Medical Center have developed a remote proton radiation therapy solution with the goals of improving access to proton radiation therapy for Department of Defense (DoD) beneficiaries while minimizing treatment delays and time spent away from home/work (time savings of up to 3 weeks per patient). To meet both Health Insurance Portability and Accountability Act guidelines and the more stringent security restrictions imposed by the DoD, our program developed a hybrid remote proton radiation therapy solution merging a CITRIX server with a JITIC-certified (Joint Interoperability Test Command) desktop videoconferencing unit. This conduit, thoroughly tested over a period of 6 months, integrates both institutions' radiation oncology treatment planning infrastructures into a single entity for DoD patients' treatment planning and delivery. This telemedicine solution enables DoD radiation oncologists and medical physicists the ability to (1) remotely access a proton therapy treatment planning platform, (2) transfer patient plans securely to the University of Pennsylvania patient database, and (3) initiate ad-hoc point-to-point and multipoint videoconferences to dynamically optimize and validate treatment plans. Our robust and secure remote treatment planning solution grants DoD patients not only access to a state-of-the-art treatment modality, but also participation in the treatment planning process by Walter Reed Army Medical Center radiation oncologists and medical physicists. This telemedicine system has the potential to lead to a greater integration of military treatment facilities and/or satellite clinics into regional proton therapy centers.

  12. 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.

  13. Generalizable class solutions for treatment planning of spinal stereotactic body radiation therapy.

    Science.gov (United States)

    Weksberg, David C; Palmer, Matthew B; Vu, Khoi N; Rebueno, Neal C; Sharp, Hadley J; Luo, Dershan; Yang, James N; Shiu, Almon S; Rhines, Laurence D; McAleer, Mary Frances; Brown, Paul D; Chang, Eric L

    2012-11-01

    Spinal stereotactic body radiation therapy (SBRT) continues to emerge as an effective therapeutic approach to spinal metastases; however, treatment planning and delivery remain resource intensive at many centers, which may hamper efficient implementation in clinical practice. We sought to develop a generalizable class solution approach for spinal SBRT treatment planning that would allow confidence that a given plan provides optimal target coverage, reduce integral dose, and maximize planning efficiency. We examined 91 patients treated with spinal SBRT at our institution. Treatment plans were categorized by lesion location, clinical target volume (CTV) configuration, and dose fractionation scheme, and then analyzed to determine the technically achievable dose gradient. A radial cord expansion was subtracted from the CTV to yield a planning CTV (pCTV) construct for plan evaluation. We reviewed the treatment plans with respect to target coverage, dose gradient, integral dose, conformality, and maximum cord dose to select the best plans and develop a set of class solutions. The class solution technique generated plans that maintained target coverage and improved conformality (1.2-fold increase in the 95% van't Riet Conformation Number describing the conformality of a reference dose to the target) while reducing normal tissue integral dose (1.3-fold decrease in the volume receiving 4 Gy (V(4Gy)) and machine output (19% monitor unit (MU) reduction). In trials of planning efficiency, the class solution technique reduced treatment planning time by 30% to 60% and MUs required by ∼20%: an effect independent of prior planning experience. We have developed a set of class solutions for spinal SBRT that incorporate a pCTV metric for plan evaluation while yielding dosimetrically superior treatment plans with increased planning efficiency. Our technique thus allows for efficient, reproducible, and high-quality spinal SBRT treatment planning. Copyright © 2012. Published by

  14. A Monte Carlo-based treatment-planning tool for ion beam therapy

    CERN Document Server

    Böhlen, T T; Dosanjh, M; Ferrari, A; Haberer, T; Parodi, K; Patera, V; Mairan, A

    2013-01-01

    Ion beam therapy, as an emerging radiation therapy modality, requires continuous efforts to develop and improve tools for patient treatment planning (TP) and research applications. Dose and fluence computation algorithms using the Monte Carlo (MC) technique have served for decades as reference tools for accurate dose computations for radiotherapy. In this work, a novel MC-based treatment-planning (MCTP) tool for ion beam therapy using the pencil beam scanning technique is presented. It allows single-field and simultaneous multiple-fields optimization for realistic patient treatment conditions and for dosimetric quality assurance for irradiation conditions at state-of-the-art ion beam therapy facilities. It employs iterative procedures that allow for the optimization of absorbed dose and relative biological effectiveness (RBE)-weighted dose using radiobiological input tables generated by external RBE models. Using a re-implementation of the local effect model (LEM), theMCTP tool is able to perform TP studies u...

  15. Developing a treatment planning process and software for improved translation of photodynamic therapy

    Science.gov (United States)

    Cassidy, J.; Zheng, Z.; Xu, Y.; Betz, V.; Lilge, L.

    2017-04-01

    Background: The majority of de novo cancers are diagnosed in low and middle-income countries, which often lack the resources to provide adequate therapeutic options. None or minimally invasive therapies such as Photodynamic Therapy (PDT) or photothermal therapies could become part of the overall treatment options in these countries. However, widespread acceptance is hindered by the current empirical training of surgeons in these optical techniques and a lack of easily usable treatment optimizing tools. Methods: Based on image processing programs, ITK-SNAP, and the publicly available FullMonte light propagation software, a work plan is proposed that allows for personalized PDT treatment planning. Starting with, contoured clinical CT or MRI images, the generation of 3D tetrahedral models in silico, execution of the Monte Carlo simulation and presentation of the 3D fluence rate, Φ, [mWcm-2] distribution a treatment plan optimizing photon source placement is developed. Results: Permitting 1-2 days for the installation of the required programs, novices can generate their first fluence, H [Jcm-2] or Φ distribution in a matter of hours. This is reduced to 10th of minutes with some training. Executing the photon simulation calculations is rapid and not the performance limiting process. Largest sources of errors are uncertainties in the contouring and unknown tissue optical properties. Conclusions: The presented FullMonte simulation is the fastest tetrahedral based photon propagation program and provides the basis for PDT treatment planning processes, enabling a faster proliferation of low cost, minimal invasive personalized cancer therapies.

  16. SU-E-T-56: Brain Metastasis Treatment Plans for Contrast-Enhanced Synchrotron Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Obeid, L; Adam, J [Grenoble Institut des Neurosciences, La Tronche, Rhone-Alpes (France); Tessier, A [Centre Hospitalier Universitaire, La Tronche, Rhone-Alpes (France); Vautrin, M; Benkebil, M [DOSIsoft, Cachan, Ile de France (France); Sihanath, R [Centre Hospitalier Universitaire, La Tronche, Rhone- Alpes (France)

    2014-06-01

    Purpose: Iodine-enhanced radiotherapy is an innovative treatment combining the selective accumulation of an iodinated contrast agent in brain tumors with irradiations using monochromatic medium energy x-rays. The aim of this study is to compare dynamic stereotactic arc-therapy and iodineenhanced SSRT. Methods: Five patients bearing brain metastasis received a standard helical 3D-scan without iodine. A second scan was acquired 13 min after an 80 g iodine infusion. Two SSRT treatment plans (with/without iodine) were performed for each patient using a dedicated Monte Carlo (MC) treatment planning system (TPS) based on the ISOgray TPS. Ten coplanar beams (6×6 cm2, shaped with collimator) were simulated. MC statistical error objective was less than 5% in the 50% isodose. The dynamic arc-therapy plan was achieved on the Iplan Brainlab TPS. The treatment plan validation criteria were fixed such that 100% of the prescribed dose is delivered at the beam isocentre and the 70% isodose contains the whole target volume. The comparison elements were the 70% isodose volume, the average and maximum doses delivered to organs at risk (OAR): brainstem, optical nerves, chiasma, eyes, skull bone and healthy brain parenchyma. Results: The stereotactic dynamic arc-therapy remains the best technique in terms of dose conformation. Iodine-enhanced SSRT presents similar performances to dynamic arc-therapy with increased brainstem and brain parenchyma sparing. One disadvantage of SSRT is the high dose to the skull bone. Iodine accumulation in metastasis may increase the dose by 20–30%, allowing a normal tissue sparing effect at constant prescribed dose. Treatment without any iodine enhancement (medium-energy stereotactic radiotherapy) is not relevant with degraded HDVs (brain, parenchyma and skull bone) comparing to stereotactic dynamic arc-therapy. Conclusion: Iodine-enhanced SSRT exhibits a good potential for brain metastasis treatment regarding the dose distribution and OAR criteria.

  17. 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.

  18. 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.

  19. Photodynamic therapy in neurosurgery: a proof of concept of treatment planning system

    Science.gov (United States)

    Dupont, C.; Reyns, N.; Mordon, S.; Vermandel, M.

    2017-02-01

    Glioblastoma (GBM) is the most common primary brain tumor. PhotoDynamic Therapy (PDT) appears as an interesting research field to improve GBM treatment. Nevertheless, PDT cannot fit into the current therapeutic modalities according to several reasons: the lack of reliable and reproducible therapy schemes (devices, light delivery system), the lack of consensus on a photosensitizer and the absence of randomized and controlled multicenter clinical trial. The main objective of this study is to bring a common support for PDT planning. Here, we describe a proof of concept of Treatment Planning System (TPS) dedicated to interstitial PDT for GBM treatment. The TPS was developed with the integrated development environment C++ Builder XE8 and the environment ArtiMED, developed in our laboratory. This software enables stereotactic registration of DICOM images, light sources insertion and an accelerated CUDA GPU dosimetry modeling. Although, Monte-Carlo is more robust to describe light diffusion in biological tissue, analytical model accelerated by GPU remains relevant for dose preview or fast reverse planning processes. Finally, this preliminary work proposes a new tool to plan interstitial or intraoperative PDT treatment and might be included in the design of future clinical trials in order to deliver PDT straightforwardly and homogenously in investigator centers.

  20. An Approach in Radiation Therapy Treatment Planning: A Fast, GPU-Based Monte Carlo Method.

    Science.gov (United States)

    Karbalaee, Mojtaba; Shahbazi-Gahrouei, Daryoush; Tavakoli, Mohammad B

    2017-01-01

    An accurate and fast radiation dose calculation is essential for successful radiation radiotherapy. The aim of this study was to implement a new graphic processing unit (GPU) based radiation therapy treatment planning for accurate and fast dose calculation in radiotherapy centers. A program was written for parallel running based on GPU. The code validation was performed by EGSnrc/DOSXYZnrc. Moreover, a semi-automatic, rotary, asymmetric phantom was designed and produced using a bone, the lung, and the soft tissue equivalent materials. All measurements were performed using a Mapcheck dosimeter. The accuracy of the code was validated using the experimental data, which was obtained from the anthropomorphic phantom as the gold standard. The findings showed that, compared with those of DOSXYZnrc in the virtual phantom and for most of the voxels (>95%), GPU-based Monte Carlo method in dose calculation may be useful in routine radiation therapy centers as the core and main component of a treatment planning verification system.

  1. Scanned ion beam therapy for prostate carcinoma. Comparison of single plan treatment and daily plan-adapted treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hild, Sebastian [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Department of Biophysics, Darmstadt (Germany); University Clinic Erlangen and Friedrich- Alexander-University Erlangen-Nuernberg (FAU), Department of Radiation Oncology, Erlangen (Germany); Graeff, Christian [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Department of Biophysics, Darmstadt (Germany); Rucinski, Antoni [University Clinic Heidelberg, Heidelberg Ion-Beam Therapy Center (HIT) and Department of Radiation Oncology, Heidelberg (Germany); Sapienza Universit' a di Roma, Dipartimento di Scienze di Base e Applicate per Ingegneria, Roma (Italy); INFN, Roma (Italy); Zink, Klemens [University of Applied Sciences, Institute for Medical Physics and Radiation Protection, Giessen (Germany); University Medical Center Giessen-Marburg, Department of Radiotherapy and Radiooncology, Marburg (Germany); Habl, Gregor [University Clinic Heidelberg, Heidelberg Ion-Beam Therapy Center (HIT) and Department of Radiation Oncology, Heidelberg (Germany); Klinikum rechts der Isar, Technische Universitaet Muenchen (TUM), Department of Radiation Oncology, Munich (Germany); Durante, Marco [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Department of Biophysics, Darmstadt (Germany); Technische Universitaet Darmstadt, Faculty of Physics, Darmstadt (Germany); Herfarth, Klaus [University Clinic Heidelberg, Heidelberg Ion-Beam Therapy Center (HIT) and Department of Radiation Oncology, Heidelberg (Germany); Bert, Christoph [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Department of Biophysics, Darmstadt (Germany); University Clinic Erlangen and Friedrich- Alexander-University Erlangen-Nuernberg (FAU), Department of Radiation Oncology, Erlangen (Germany); University Hospital Erlangen, Radiation Oncology, Erlangen (Germany)

    2016-02-15

    Intensity-modulated particle therapy (IMPT) for tumors showing interfraction motion is a topic of current research. The purpose of this work is to compare three treatment strategies for IMPT to determine potential advantages and disadvantages of ion prostate cancer therapy. Simulations for three treatment strategies, conventional one-plan radiotherapy (ConvRT), image-guided radiotherapy (IGRT), and online adaptive radiotherapy (ART) were performed employing a dataset of 10 prostate cancer patients with six CT scans taken at one week intervals. The simulation results, using a geometric margin concept (7-2 mm) as well as patient-specific internal target volume definitions for IMPT were analyzed by target coverage and exposure of critical structures on single fraction dose distributions. All strategies led to clinically acceptable target coverage in patients exhibiting small prostate motion (mean displacement < 4 mm), but IGRT and especially ART led to significant sparing of the rectum. In 20 % of the patients, prostate motion exceeded 4 mm causing insufficient target coverage for ConvRT (V95{sub mean} = 0.86, range 0.63-0.99) and IGRT (V95{sub mean} = 0.91, range 0.68-1.00), while ART maintained acceptable target coverage. IMPT of prostate cancer demands consideration of rectal sparing and adaptive treatment replanning for patients exhibiting large prostate motion. (orig.) [German] Adaptive Therapieansaetze fuer sich interfraktionell bewegende Zielvolumina in der intensitaetsmodulierten Partikeltherapie (IMPT) befinden sich zurzeit in der Entwicklung. In dieser Arbeit werden drei Behandlungsstrategien auf moegliche Vor- und Nachteile in der IMPT des Prostatakarzinoms hin untersucht. Auf Basis eines anonymisierten Datensatzes aus 10 Patienten mit Prostatakarzinom wurden die drei Bestrahlungsstrategien, konventionelle Ein-Plan-Strahlentherapie (ConvRT), bildunterstuetzte Strahlentherapie (IGRT) und tagesaktuelle Strahlentherapie (adaptive radiotherapy,ART), simuliert

  2. SU-F-T-617: Remotely Pre-Planned Stereotactic Ablative Radiation Therapy: Validation of Treatment Plan Quality

    Energy Technology Data Exchange (ETDEWEB)

    Juang, T; Bush, K; Loo, B; Gensheimer, M [Stanford University, Stanford, CA (United States)

    2016-06-15

    Purpose: We propose a workflow to improve access to stereotactic ablative radiation therapy (SABR) for rural patients. When implemented, a separate trip to the central facility for simulation can be eliminated. Two elements are required: (1) Fabrication of custom immobilization devices to match positioning on prior diagnostic CT (dxCT). (2) Remote radiation pre-planning on dxCT, with transfer of contours/plan to simulation CT (simCT) and initiation of treatment same-day or next day. In this retrospective study, we validated part 2 of the workflow using patients already treated with SABR for upper lobe lung tumors. Methods: Target/normal structures were contoured on dxCT; a plan was created and approved by the physician. Structures were transferred to simCT using deformable image registration and the plan was re-optimized on simCT. Plan quality was evaluated through comparison to gold-standard structures contoured on simCT and a gold-standard plan based on these structures. Workflow-generated plan quality in this study represents a worst-case scenario as these patients were not treated using custom immobilization to match dxCT position as would be done when the workflow is implemented clinically. Results: 5/6 plans created through the pre-planning workflow were clinically acceptable. For all six plans, the gold-standard GTV received full prescription dose, along with median PTV V95%=95.2% and median PTV D95%=95.4%. Median GTV DSC=0.80, indicating high degree of similarity between the deformed and gold-standard GTV contours despite small GTV sizes (mean=3.0cc). One outlier (DSC=0.49) resulted in inadequate PTV coverage (V95%=62.9%) in the workflow plan; in clinical practice, this mismatch between deformed/gold-standard GTV would be revised by the physician after deformable registration. For all patients, normal tissue doses were comparable to the gold-standard plan and well within constraints. Conclusion: Pre-planning SABR cases on diagnostic imaging generated

  3. MO-D-BRB-00: Pediatric Radiation Therapy Planning, Treatment, and Late Effects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Most Medical Physicists working in radiotherapy departments see few pediatric patients. This is because, fortunately, children get cancer at a rate nearly 100 times lower than adults. Children have not smoked, abused alcohol, or been exposed to environmental carcinogens for decades, and of course, have not fallen victim to the aging process. Children get very different cancers than adults. Breast or prostate cancers, typical in adults, are rarely seen in children but instead a variety of tumors occur in children that are rarely seen in adults; examples are germinomas, ependymomas and primitive neuroectodermal tumors, which require treatment of the child’s brain or neuroblastoma, requiring treatment in the abdomen. The treatment of children with cancer using radiation therapy is one of the most challenging planning and delivery problems facing the physicist. This is because bones, brain, breast tissue, and other organs are more sensitive to radiation in children than in adults. Because most therapy departments treat mostly adults, when the rare 8 year-old patient comes to the department for treatment, the physicist may not understand the clinical issues of his disease which drive the planning and delivery decisions. Additionally, children are more prone than adults to developing secondary cancers after radiation. For bilateral retinoblastoma for example, an irradiated child has a 40% chance of developing a second cancer by age 50. The dosimetric tradeoffs made during the planning process are complex and require careful consideration for children treated with radiotherapy. In the first presentation, an overview of childhood cancers and their corresponding treatment techniques will be given. These can be some of the most complex treatments that are delivered in the radiation therapy department. These cancers include leukemia treated with total body irradiation, medulloblastoma, treated with craniospinal irradiation plus a conformal boost to the posterior fossa

  4. Microbeam radiation therapy. Physical and biological aspects of a new cancer therapy and development of a treatment planning system

    Energy Technology Data Exchange (ETDEWEB)

    Bartzsch, Stefan

    2014-11-05

    Microbeam Radiation Therapy (MRT) is a novel treatment strategy against cancer. Highly brilliant synchrotron radiation is collimated to parallel, a few micrometre wide, planar beams and used to irradiate malignant tissues with high doses. The applied peak doses are considerably higher than in conventional radiotherapy, but valley doses between the beams remain underneath the established tissue tolerance. Previous research has shown that these beam geometries spare normal tissue, while being effective in tumour ablation. In this work physical and biological aspects of the therapy were investigated. A therapy planning system was developed for the first clinical treatments at the European Synchrotron Radiation Facility in Grenoble (France) and a dosimetry method based on radiochromic films was created to validate planned doses with measurements on a micrometre scale. Finally, experiments were carried out on a cellular level in order to correlate the physically planned doses with the biological damage caused in the tissue. The differences between Monte Carlo dose and dosimetry are less than 10% in the valley and 5% in the peak regions. Developed alternative faster dose calculation methods deviate from the computational intensive MC simulations by less than 15% and are able to determine the dose within a few minutes. The experiments in cell biology revealed an significant influence of intercellular signalling on the survival of cells close to radiation boundaries. These observations may not only be important for MRT but also for conventional radiotherapy.

  5. Development of an autonomous treatment planning strategy for radiation therapy with effective use of population-based prior data.

    Science.gov (United States)

    Wang, Huan; Dong, Peng; Liu, Hongcheng; Xing, Lei

    2017-02-01

    Current treatment planning remains a costly and labor intensive procedure and requires multiple trial-and-error adjustments of system parameters such as the weighting factors and prescriptions. The purpose of this work is to develop an autonomous treatment planning strategy with effective use of prior knowledge and in a clinically realistic treatment planning platform to facilitate radiation therapy workflow. Our technique consists of three major components: (i) a clinical treatment planning system (TPS); (ii) a formulation of decision-function constructed using an assemble of prior treatment plans; (iii) a plan evaluator or decision-function and an outer-loop optimization independent of the clinical TPS to assess the TPS-generated plan and to drive the search toward a solution optimizing the decision-function. Microsoft (MS) Visual Studio Coded UI is applied to record some common planner-TPS interactions as subroutines for querying and interacting with the TPS. These subroutines are called back in the outer-loop optimization program to navigate the plan selection process through the solution space iteratively. The utility of the approach is demonstrated by using clinical prostate and head-and-neck cases. An autonomous treatment planning technique with effective use of an assemble of prior treatment plans is developed to automatically maneuver the clinical treatment planning process in the platform of a commercial TPS. The process mimics the decision-making process of a human planner and provides a clinically sensible treatment plan automatically, thus reducing/eliminating the tedious manual trial-and-errors of treatment planning. It is found that the prostate and head-and-neck treatment plans generated using the approach compare favorably with that used for the patients' actual treatments. Clinical inverse treatment planning process can be automated effectively with the guidance of an assemble of prior treatment plans. The approach has the potential to

  6. A fast - Monte Carlo toolkit on GPU for treatment plan dose recalculation in proton therapy

    Science.gov (United States)

    Senzacqua, M.; Schiavi, A.; Patera, V.; Pioli, S.; Battistoni, G.; Ciocca, M.; Mairani, A.; Magro, G.; Molinelli, S.

    2017-10-01

    In the context of the particle therapy a crucial role is played by Treatment Planning Systems (TPSs), tools aimed to compute and optimize the tratment plan. Nowadays one of the major issues related to the TPS in particle therapy is the large CPU time needed. We developed a software toolkit (FRED) for reducing dose recalculation time by exploiting Graphics Processing Units (GPU) hardware. Thanks to their high parallelization capability, GPUs significantly reduce the computation time, up to factor 100 respect to a standard CPU running software. The transport of proton beams in the patient is accurately described through Monte Carlo methods. Physical processes reproduced are: Multiple Coulomb Scattering, energy straggling and nuclear interactions of protons with the main nuclei composing the biological tissues. FRED toolkit does not rely on the water equivalent translation of tissues, but exploits the Computed Tomography anatomical information by reconstructing and simulating the atomic composition of each crossed tissue. FRED can be used as an efficient tool for dose recalculation, on the day of the treatment. In fact it can provide in about one minute on standard hardware the dose map obtained combining the treatment plan, earlier computed by the TPS, and the current patient anatomic arrangement.

  7. 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.

  8. Automatic MRI Atlas-Based External Beam Radiation Therapy Treatment Planning for Prostate Cancer

    Science.gov (United States)

    Dowling, Jason; Lambert, Jonathan; Parker, Joel; Greer, Peter B.; Fripp, Jurgen; Denham, James; Ourselin, Sébastien; Salvado, Olivier

    Prostate radiation therapy dose planning currently requires computed tomography (CT) scans as they contain electron density information needed for patient dose calculations. However magnetic resonance imaging (MRI) images have significantly superior soft-tissue contrast for segmenting organs of interest and determining the target volume for treatment. This paper describes work on the development of an alternative treatment workflow enabling both organ delineation and dose planning to be performed using MRI alone. This is achieved by atlas based segmentation and the generation of pseudo-CT scans from MRI. Planning and dosimetry results for three prostate cancer patients from Calvary Mater Newcastle Hospital (Australia) are presented supporting the feasibility of this workflow. Good DSC scores were found for the atlas based segmentation of the prostate (mean 0.84) and bones (mean 0.89). The agreement between MRI/pseudo-CT and CT planning was quantified by dose differences and distance to agreement in corresponding voxels. Dose differences were found to be less than 2%. Chi values indicate that the planning CT and pseudo-CT dose distributions are equivalent.

  9. SU-F-T-128: Dose-Volume Constraints for Particle Therapy Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, R; Smith, W; Hendrickson, K; Meyer, J; Cao, N; Lee, E; Gopan, O; Sandison, G; Parvathaneni, U; Laramore, G [University of Washington, Seattle, WA (United States)

    2016-06-15

    Purpose: Determine equivalent Organ at Risk (OAR) tolerance dose (TD) constraints for MV x-rays and particle therapy. Methods: Equivalent TD estimates for MV x-rays are determined from an isoeffect, regression-analysis of published and in-house constraints for various fractionation schedules (n fractions). The analysis yields an estimate of (α/β) for an OAR. To determine equivalent particle therapy constraints, the MV x-ray TD(n) values are divided by the RBE for DSB induction (RBE{sub DSB}) or cell survival (RBE{sub S}). Estimates of (RBE{sub DSB}) are computed using the Monte Carlo Damage Simulation, and estimates of RBES are computed using the Repair-Misrepair-Fixation (RMF) model. A research build of the RayStation™ treatment planning system implementing the above model is used to estimate (RBE{sub DSB}) for OARs of interest in 16 proton therapy patient plans (head and neck, thorax, prostate and brain). Results: The analysis gives an (α/β) estimate of about 20 Gy for the trachea and heart and 2–4 Gy for the esophagus, spine, and brachial plexus. Extrapolation of MV x-ray constraints (n = 1) to fast neutrons using RBE{sub DSB} = 2.7 are in excellent agreement with clinical experience (n = 10 to 20). When conventional (n > 30) x-ray treatments are used as the reference radiation, fast neutron RBE increased to a maximum of 6. For comparison to a constant RBE of 1.1, the RayStation™ analysis gave estimates of proton RBE{sub DSB} from 1.03 to 1.33 for OARs of interest. Conclusion: The presented system of models is a convenient formalism to synthesize from multiple sources of information a set of self-consistent plan constraints for MV x-ray and hadron therapy treatments. Estimates of RBE{sub DSB} from the RayStation™ analysis differ substantially from 1.1 and vary among patients and treatment sites. A treatment planning system that incorporates patient and anatomy-specific corrections in proton RBE would create opportunities to increase the therapeutic

  10. Feasibility of Proton Beam Therapy for Ocular Melanoma Using a Novel 3D Treatment Planning Technique

    Energy Technology Data Exchange (ETDEWEB)

    Hartsell, William F., E-mail: whartsell@chicagocancer.org [Northwestern Medicine Chicago Proton Center, Proton Collaborative Group, Warrenville, Illinois (United States); Kapur, Rashmi [Retina Consultants, Des Plaines, Illinois (United States); Hartsell, Siobhan O' Connor; Sweeney, Patrick [Northwestern Medicine Chicago Proton Center, Warrenville, Illinois (United States); Lopes, Caitlin [Rush Medical College, Chicago, Illinois (United States); Duggal, Amanda [Northwestern Medicine Chicago Proton Center, Warrenville, Illinois (United States); Cohen, Jack [Department of Ophthalmology, Rush University, Chicago, Illinois (United States); Chang, John [Northwestern Medicine Chicago Proton Center, Proton Collaborative Group, Warrenville, Illinois (United States); Polasani, Rajeev S. [Northwestern Medicine Central DuPage Hospital, Winfield, Illinois (United States); Dunn, Megan [Northwestern Medicine Chicago Proton Center, Proton Collaborative Group, Warrenville, Illinois (United States); Pankuch, Mark [Northwestern Medicine Chicago Proton Center, Proton Collaborative Group, Warrenville, Illinois (United States)

    2016-05-01

    Purpose: We evaluated sparing of normal structures using 3-dimensional (3D) treatment planning for proton therapy of ocular melanomas. Methods and Materials: We evaluated 26 consecutive patients with choroidal melanomas on a prospective registry. Ophthalmologic work-up included fundoscopic photographs, fluorescein angiography, ultrasonographic evaluation of tumor dimensions, and magnetic resonance imaging of orbits. Three tantalum clips were placed as fiducial markers to confirm eye position for treatment. Macula, fovea, optic disc, optic nerve, ciliary body, lacrimal gland, lens, and gross tumor volume were contoured on treatment planning compute tomography scans. 3D treatment planning was performed using noncoplanar field arrangements. Patients were typically treated with 3 fields, with at least 95% of planning target volume receiving 50 GyRBE in 5 fractions. Results: Tumor stage was T1a in 10 patients, T2a in 10 patients, T2b in 1 patient, T3a in 2 patients, T3b in 1 patient, and T4a in 2 patients. Acute toxicity was mild. All patients completed treatment as planned. Mean optic nerve dose was 10.1 Gy relative biological effectiveness (RBE). Ciliary body doses were higher for nasal (mean: 11.4 GyRBE) than temporal tumors (5.8 GyRBE). Median follow-up was 31 months (range: 18-40 months). Six patients developed changes which required intraocular bevacizumab or corticosteroid therapy, but only 1 patient developed neovascular glaucoma. Five patients have since died: 1 from metastatic disease and 4 from other causes. Two patients have since required enucleation: 1 due to tumor and 1 due to neovascular glaucoma. Conclusions: 3D treatment planning can be used to obtain appropriate coverage of choroidal melanomas. This technique is feasible with relatively low doses to anterior structures, and appears to have acceptable rates of local control with low risk of enucleation. Further evaluation and follow-up is needed to determine optimal dose-volume relationships for

  11. Head and Neck Margin Reduction With Adaptive Radiation Therapy: Robustness of Treatment Plans Against Anatomy Changes

    Energy Technology Data Exchange (ETDEWEB)

    Kranen, Simon van; Hamming-Vrieze, Olga; Wolf, Annelisa; Damen, Eugène [Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam (Netherlands); Herk, Marcel van [Christie Hospital and University of Manchester, Manchester (United Kingdom); Sonke, Jan-Jakob, E-mail: j.sonke@nki.nl [Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam (Netherlands)

    2016-11-01

    Purpose: We set out to investigate loss of target coverage from anatomy changes in head and neck cancer patients as a function of applied safety margins and to verify a cone beam computed tomography (CBCT)–based adaptive strategy with an average patient anatomy to overcome possible target underdosage. Methods and Materials: For 19 oropharyngeal cancer patients, volumetric modulated arc therapy treatment plans (2 arcs; simultaneous integrated boost, 70 and 54.25 Gy; 35 fractions) were automatically optimized with uniform clinical target volume (CTV)–to–planning target volume margins of 5, 3, and 0 mm. We applied b-spline CBCT–to–computed tomography (CT) deformable registration to allow recalculation of the dose on modified CT scans (planning CT deformed to daily CBCT following online positioning) and dose accumulation in the planning CT scan. Patients with deviations in primary or elective CTV coverage >2 Gy were identified as candidates for adaptive replanning. For these patients, a single adaptive intervention was simulated with an average anatomy from the first 10 fractions. Results: Margin reduction from 5 mm to 3 mm to 0 mm generally led to an organ-at-risk (OAR) mean dose (D{sub mean}) sparing of approximately 1 Gy/mm. CTV shrinkage was mainly seen in the elective volumes (up to 10%), likely related to weight loss. Despite online repositioning, substantial systematic errors were present (>3 mm) in lymph node CTV, the parotid glands, and the larynx. Nevertheless, the average increase in OAR dose was small: maximum of 1.2 Gy (parotid glands, D{sub mean}) for all applied margins. Loss of CTV coverage >2 Gy was found in 1, 3, and 7 of 73 CTVs, respectively. Adaptive intervention in 0-mm plans substantially improved coverage: in 5 of 7 CTVs (in 6 patients) to <2 Gy of initially planned. Conclusions: Volumetric modulated arc therapy head and neck cancer treatment plans with 5-mm margins are robust for anatomy changes and show a modest

  12. An efficient Volumetric Arc Therapy treatment planning approach for hippocampal-avoidance whole-brain radiation therapy (HA-WBRT)

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Jin [Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY (United States); Bender, Edward [Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Yaparpalvi, Ravindra; Kuo, Hsiang-Chi; Basavatia, Amar; Hong, Linda; Bodner, William; Garg, Madhur K.; Kalnicki, Shalom [Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY (United States); Tomé, Wolfgang A., E-mail: wtome@montefiore.org [Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States)

    2015-10-01

    An efficient and simple class solution is proposed for hippocampal-avoidance whole-brain radiation therapy (HA-WBRT) planning using the Volumetric Arc Therapy (VMAT) delivery technique following the NRG Oncology protocol NRG-CC001 treatment planning guidelines. The whole-brain planning target volume (PTV) was subdivided into subplanning volumes that lie in plane and out of plane with the hippocampal-avoidance volume. To further improve VMAT treatment plans, a partial-field dual-arc technique was developed. Both the arcs were allowed to overlap on the in-plane subtarget volume, and in addition, one arc covered the superior out-of-plane sub-PTV, while the other covered the inferior out-of-plane subtarget volume. For all plans (n = 20), the NRG-CC001 protocol dose-volume criteria were met. Mean values of volumes for the hippocampus and the hippocampal-avoidance volume were 4.1 cm{sup 3} ± 1.0 cm{sup 3} and 28.52 cm{sup 3} ± 3.22 cm{sup 3}, respectively. For the PTV, the average values of D{sub 2%} and D{sub 98%} were 36.1 Gy ± 0.8 Gy and 26.2 Gy ± 0.6 Gy, respectively. The hippocampus D{sub 100%} mean value was 8.5 Gy ± 0.2 Gy and the maximum dose was 15.7 Gy ± 0.3 Gy. The corresponding plan quality indices were 0.30 ± 0.01 (homogeneity index), 0.94 ± 0.01 (target conformality), and 0.75 ± 0.02 (confirmation number). The median total monitor unit (MU) per fraction was 806 MU (interquartile range [IQR]: 792 to 818 MU) and the average beam total delivery time was 121.2 seconds (IQR: 120.6 to 121.35 seconds). All plans passed the gamma evaluation using the 5-mm, 4% criteria, with γ > 1 of not more than 9.1% data points for all fields. An efficient and simple planning class solution for HA-WBRT using VMAT has been developed that allows all protocol constraints of NRG-CC001 to be met.

  13. Virtual commissioning of a treatment planning system for proton therapy of ocular cancers.

    Science.gov (United States)

    Koch, N; Newhauser, W

    2005-01-01

    The virtual commissioning of a treatment planning system (TPS) for ocular proton beam therapy was performed using Monte Carlo (MC) simulations and a model of a double-scattering ocular treatment nozzle. The simulations produced both the input data required by the TPS and the dose distributions to validate the analytical predictions from the TPS. An MC simulation of a typical ocular melanoma treatment was compared with the TPS predictions, revealing generally good agreement in the absorbed dose distribution. However, in the depth-dose profiles, differences >5% existed in the proximal region of all validation cases considered. Comparison of the radiation coverage at or above the 90% dose level, showed that MC calculated coverage was 82% and 68% of the coverage calculated by the TPS in two planes intersecting the tumour.

  14. Upgrade and benchmarking of a 4D treatment planning system for scanned ion beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Richter, D.; Schwarzkopf, A.; Trautmann, J.; Durante, M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Abt. Biophysik, Planckstrasse 1, 64291 Darmstadt (Germany); TU Darmstadt, Hochschulstrasse 6, 64289 Darmstadt (Germany); Kraemer, M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Abt. Biophysik, Planckstrasse 1, 64291 Darmstadt (Germany); Jaekel, O. [Clinic for Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld, Heidelberg 69120 (Germany); Bert, C. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Abt. Biophysik, Planckstrasse 1, 64291 Darmstadt (Germany); Department of Radiation Oncology, University Hospital Erlangen, Universitaetsstr. 27, 91054 Erlangen (Germany)

    2013-05-15

    Purpose: Upgrade and benchmarking of a research 4D treatment planning system (4DTPS) suitable for realistic patient treatment planning and treatment simulations taking into account specific requirements for scanned ion beam therapy, i.e., modeling of dose heterogeneities due to interplay effects and range changes caused by patient motion and dynamic beam delivery. Methods: The 4DTPS integrates data interfaces to 4D computed tomography (4DCT), deformable image registration and clinically used motion monitoring devices. The authors implemented a novel data model for 4D image segmentation using Boolean mask volume datasets and developed an algorithm propagating a manually contoured reference contour dataset to all 4DCT phases. They further included detailed treatment simulation and dose reconstruction functionality, based on the irregular patient motion and the temporal structure of the beam delivery. The treatment simulation functionality was validated against experimental data from irradiation of moving radiographic films in air, 3D moving ionization chambers in a water phantom, and moving cells in a biological phantom with a scanned carbon ion beam. The performance of the program was compared to results obtained with predecessor programs. Results: The measured optical density distributions of the radiographic films were reproduced by the simulations to (-2 {+-} 12)%. Compared to earlier versions of the 4DTPS, the mean agreement improved by 2%, standard deviations were reduced by 7%. The simulated dose to the moving ionization chambers in water showed an agreement with the measured dose of (-1 {+-} 4)% for the typical beam configuration. The mean deviation of the simulated from the measured biologically effective dose determined via cell survival was (617 {+-} 538) mGy relative biological effectiveness corresponding to (10 {+-} 9)%. Conclusions: The authors developed a research 4DTPS suitable for realistic treatment planning on patient data and capable of simulating

  15. Treatment planning for internal emitter therapy: Methods, applications and clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Sgouros, G. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    1999-01-01

    Treatment planning involves three basic steps: (1) a procedure must be devised that will provide the most relevant information, (2) the procedure must be applied and (3) the resulting information must be translated into a definition of the optimum implementation. There are varying degrees of treatment planning that may be implemented in internal emitter therapy. As in chemotherapy, the information from a Phase 1 study may be used to treat patients based upon body surface area. If treatment planning is included on a patient-specific basis, a pretherapy, trace-labeled, administration of the radiopharmaceutical is generally required. The data collected following the tracer dose may range from time-activity curves of blood and whole-body for use in blood, marrow or total body absorbed dose estimation to patient imaging for three-dimensional internal emitter dosimetry. The most ambitious approach requires a three-dimensional set of images representing radionuclide distribution (SPECT or PET) and a corresponding set of images representing anatomy (CT or MRI). The absorbed dose (or dose-rate) distribution may be obtained by convolution of a point kernel with the radioactivity distribution or by direct Monte Carlo calculation. A critical requirement for both techniques is the development of an overall structure that makes it possible, in a routine manner, to input the images, to identify the structures of interest and to display the results of the dose calculations in a clinically relevant manner. 52 refs., 4 figs., 1 tab.

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

    Science.gov (United States)

    Wooten, H Omar; 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

    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. The ViewRay treatment planning system (Oakwood Village, OH) was used to create (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 (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. All (60)Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for (60)Co was within 20 Gy. The mean doses for all (60)Co plan OARs were within clinical tolerances. A commercial (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. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Randomized algorithms for high quality treatment planning in volumetric modulated arc therapy

    Science.gov (United States)

    Yang, Yu; Dong, Bin; Wen, Zaiwen

    2017-02-01

    In recent years, volumetric modulated arc therapy (VMAT) has been becoming a more and more important radiation technique widely used in clinical application for cancer treatment. One of the key problems in VMAT is treatment plan optimization, which is complicated due to the constraints imposed by the involved equipments. In this paper, we consider a model with four major constraints: the bound on the beam intensity, an upper bound on the rate of the change of the beam intensity, the moving speed of leaves of the multi-leaf collimator (MLC) and its directional-convexity. We solve the model by a two-stage algorithm: performing minimization with respect to the shapes of the aperture and the beam intensities alternatively. Specifically, the shapes of the aperture are obtained by a greedy algorithm whose performance is enhanced by random sampling in the leaf pairs with a decremental rate. The beam intensity is optimized using a gradient projection method with non-monotonic line search. We further improve the proposed algorithm by an incremental random importance sampling of the voxels to reduce the computational cost of the energy functional. Numerical simulations on two clinical cancer date sets demonstrate that our method is highly competitive to the state-of-the-art algorithms in terms of both computational time and quality of treatment planning.

  18. Intensity modulated radiation therapy class solutions in Philips Pinnacle treatment planning for central nervous system malignancies: Standardized, efficient, and effective.

    Science.gov (United States)

    Likhacheva, Anna; Palmer, Matthew; Du, Weiliang; Brown, Paul D; Mahajan, Anita

    2012-01-01

    The use of intensity modulated radiation therapy (IMRT) is becoming more commonplace in the treatment of central nervous system (CNS) malignancies. However, the determination of beam arrangements is still an empirical process, and optimization of any given plan may take hours on the part of the dosimetrist and the physician to achieve optimal conformity and normal tissue doses. Regional CNS class solutions (CS) for IMRT planning with the Philips Pinnacle treatment planning system (version 8.0; ADAC Laboratories, Milpitas, CA) have been in partial implementation at our institution since 2009. The purpose of this present work was to investigate their validity in clinical practice. The plans of 55 patients treated for high-grade gliomas since 2009 were analyzed retrospectively. Thirty plans were categorized as having been planned with class solutions and 25 plans with user-defined optimization. Each plan was evaluated based on the following: (1) mean dose to the brain; (2) brain V30; and (3) Radiation Therapy Oncology Group (RTOG) conformity index (CIRTOG). These data were then compared with 140 historical benchmark plans that were generated using user-defined optimization prior to 2009. The CS plans for gliomas in frontal, parietal-occipital, and temporal regions typically resulted in superior mean brain dose, brain V30, and conformity index when compared with user-defined plans. The CS plans for brainstem gliomas exhibited improved CIRTOG, but not brain V30 and brain mean dose. In trials of planning efficiency, the CS technique reduced treatment planning time by more than 2 times, independent of prior planning experience. We have developed a CS protocol for IMRT planning of gliomas that has dramatically simplified this complex planning process, allowing dosimetrists of all levels of experience to produce highly conformal plans in a time efficient manner. Copyright © 2012 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  19. Treatment planning and dose analysis for interstitial photodynamic therapy of prostate cancer

    Science.gov (United States)

    Davidson, Sean R. H.; Weersink, Robert A.; Haider, Masoom A.; Gertner, Mark R.; Bogaards, Arjen; Giewercer, David; Scherz, Avigdor; Sherar, Michael D.; Elhilali, Mostafa; Chin, Joseph L.; Trachtenberg, John; Wilson, Brian C.

    2009-04-01

    With the development of new photosensitizers that are activated by light at longer wavelengths, interstitial photodynamic therapy (PDT) is emerging as a feasible alternative for the treatment of larger volumes of tissue. Described here is the application of PDT treatment planning software developed by our group to ensure complete coverage of larger, geometrically complex target volumes such as the prostate. In a phase II clinical trial of TOOKAD vascular targeted photodynamic therapy (VTP) for prostate cancer in patients who failed prior radiotherapy, the software was used to generate patient-specific treatment prescriptions for the number of treatment fibres, their lengths, their positions and the energy each delivered. The core of the software is a finite element solution to the light diffusion equation. Validation against in vivo light measurements indicated that the software could predict the location of an iso-fluence contour to within approximately ±2 mm. The same software was used to reconstruct the treatments that were actually delivered, thereby providing an analysis of the threshold light dose required for TOOKAD-VTP of the post-irradiated prostate. The threshold light dose for VTP-induced prostate damage, as measured one week post-treatment using contrast-enhanced MRI, was found to be highly heterogeneous, both within and between patients. The minimum light dose received by 90% of the prostate, D90, was determined from each patient's dose-volume histogram and compared to six-month sextant biopsy results. No patient with a D90 less than 23 J cm-2 had complete biopsy response, while 8/13 (62%) of patients with a D90 greater than 23 J cm-2 had negative biopsies at six months. The doses received by the urethra and the rectal wall were also investigated.

  20. Treatment planning and dose analysis for interstitial photodynamic therapy of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Sean R H; Gertner, Mark R; Bogaards, Arjen; Sherar, Michael D; Wilson, Brian C [Division of Biophysics and Bioimaging, Ontario Cancer Institute, University Health Network, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Weersink, Robert A; Giewercer, David [Laboratory for Applied Biophysics, Ontario Cancer Institute, University Health Network, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Haider, Masoom A [Joint Department of Medical Imaging, University Health Network, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Scherz, Avigdor [Department of Plant Science, Weizmann Institute of Science, PO Box 26, Rehovot 76100 (Israel); Elhilali, Mostafa [Department of Surgery, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec H3G 1Y6 (Canada); Chin, Joseph L [Department of Oncology, University of Western Ontario, 800 Commissioners Road East, PO Box 5010, London, Ontario N6A 5W9 (Canada); Trachtenberg, John [Department of Urology, University Health Network, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada)], E-mail: wilson@uhnres.utoronto.ca

    2009-04-21

    With the development of new photosensitizers that are activated by light at longer wavelengths, interstitial photodynamic therapy (PDT) is emerging as a feasible alternative for the treatment of larger volumes of tissue. Described here is the application of PDT treatment planning software developed by our group to ensure complete coverage of larger, geometrically complex target volumes such as the prostate. In a phase II clinical trial of TOOKAD vascular targeted photodynamic therapy (VTP) for prostate cancer in patients who failed prior radiotherapy, the software was used to generate patient-specific treatment prescriptions for the number of treatment fibres, their lengths, their positions and the energy each delivered. The core of the software is a finite element solution to the light diffusion equation. Validation against in vivo light measurements indicated that the software could predict the location of an iso-fluence contour to within approximately {+-}2 mm. The same software was used to reconstruct the treatments that were actually delivered, thereby providing an analysis of the threshold light dose required for TOOKAD-VTP of the post-irradiated prostate. The threshold light dose for VTP-induced prostate damage, as measured one week post-treatment using contrast-enhanced MRI, was found to be highly heterogeneous, both within and between patients. The minimum light dose received by 90% of the prostate, D{sub 90}, was determined from each patient's dose-volume histogram and compared to six-month sextant biopsy results. No patient with a D{sub 90} less than 23 J cm{sup -2} had complete biopsy response, while 8/13 (62%) of patients with a D{sub 90} greater than 23 J cm{sup -2} had negative biopsies at six months. The doses received by the urethra and the rectal wall were also investigated.

  1. Analysis of fractionation correction methodologies for multiple phase treatment plans in radiation therapy.

    Science.gov (United States)

    Mavroidis, Panayiotis; Ferreira, Brigida Costa; Papanikolaou, Nikos; Lopes, Maria do Carmo

    2013-03-01

    Radiation therapy is often delivered by multiple sequential treatment plans. For an accurate radiobiological evaluation of the overall treatment, fractionation corrections to each dose distribution must be applied before summing the three-dimensional dose matrix of each plan since the simpler approach of performing the fractionation correction to the total dose-volume histograms, obtained by the arithmetical sum of the different plans, becomes inaccurate for more heterogeneous dose patterns. In this study, the differences between these two fractionation correction methods, named here as exact (corrected before) and approximate (after summation), respectively, are assessed for different cancer types. Prostate, breast, and head and neck (HN) tumor patients were selected to quantify the differences between two fractionation correction methods (the exact vs the approximate). For each cancer type, two different treatment plans were developed using uniform (CRT) and intensity modulated beams (IMRT), respectively. The responses of the target and normal tissue were calculated using the Poisson linear-quadratic-time model and the relative seriality model, respectively. All treatments were radiobiologically evaluated and compared using the complication-free tumor control probability (P+), the biologically effective uniform dose (D) together with common dosimetric criteria. For the prostate cancer patient, an underestimation of around 14%-15% in P+ was obtained when the fractionation correction was applied after summation compared to the exact approach due to significant biological and dosimetric variations obtained between the two fractionation correction methods in the involved lymph nodes. For the breast cancer patient, an underestimation of around 3%-4% in the maximum dose in the heart was obtained. Despite the dosimetric differences in this organ, no significant variations were obtained in treatment outcome. For the HN tumor patient, an underestimation of about 5% in

  2. Three-dimensional radiobiological dosimetry of kidneys for treatment planning in peptide receptor radionuclide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, Sebastien; Hobbs, Robert F.; Boubaker, Ariane; Buchegger, Franz; He Bin; Frey, Eric C.; Sgouros, George [Institute of Radiation Physics, Lausanne University Hospital, 1007 Lausanne (Switzerland); Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21231 (United States); Department of Nuclear Medicine, Lausanne University Hospital, 1011 Lausanne (Switzerland); Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21231 (United States)

    2012-10-15

    Purpose: Peptide receptor radionuclide therapy (PRRT) delivers high absorbed doses to kidneys and may lead to permanent nephropathy. Reliable dosimetry of kidneys is thus critical for safe and effective PRRT. The aim of this work was to assess the feasibility of planning PRRT based on 3D radiobiological dosimetry (3D-RD) in order to optimize both the amount of activity to administer and the fractionation scheme, while limiting the absorbed dose and the biological effective dose (BED) to the renal cortex. Methods: Planar and SPECT data were available for a patient examined with {sup 111}In-DTPA-octreotide at 0.5 (planar only), 4, 24, and 48 h post-injection. Absorbed dose and BED distributions were calculated for common therapeutic radionuclides, i.e., {sup 111}In, {sup 90}Y and {sup 177}Lu, using the 3D-RD methodology. Dose-volume histograms were computed and mean absorbed doses to kidneys, renal cortices, and medullae were compared with results obtained using the MIRD schema (S-values) with the multiregion kidney dosimetry model. Two different treatment planning approaches based on (1) the fixed absorbed dose to the cortex and (2) the fixed BED to the cortex were then considered to optimize the activity to administer by varying the number of fractions. Results: Mean absorbed doses calculated with 3D-RD were in good agreement with those obtained with S-value-based SPECT dosimetry for {sup 90}Y and {sup 177}Lu. Nevertheless, for {sup 111}In, differences of 14% and 22% were found for the whole kidneys and the cortex, respectively. Moreover, the authors found that planar-based dosimetry systematically underestimates the absorbed dose in comparison with SPECT-based methods, up to 32%. Regarding the 3D-RD-based treatment planning using a fixed BED constraint to the renal cortex, the optimal number of fractions was found to be 3 or 4, depending on the radionuclide administered and the value of the fixed BED. Cumulative activities obtained using the proposed simulated

  3. Total variation superiorization in dual-energy CT reconstruction for proton therapy treatment planning

    Science.gov (United States)

    Zhu, Jiahua; Penfold, Scott

    2017-04-01

    Proton therapy is a precise form of radiotherapy in which the range of an energetic beam of protons within a patient must be accurately known. The current approach based on single-energy computed tomography (SECT) can lead to uncertainties in the proton range of approximately 3%. This range of uncertainty may lead to under-dosing of the tumour or over-dosing of healthy tissues. Dual-energy CT (DECT) theoretically has the potential to reduce these range uncertainties by quantifying electron density and the effective atomic number. In practice, however, DECT images reconstructed with filtered backprojection (FBP) tend to suffer from high levels of noise. The objective of the current work was to examine the effect of total variation superiorization (TVS) on proton therapy planning accuracy when compared with FBP. A virtual CT scanner was created with the Monte Carlo toolkit Geant4. Tomographic images were reconstructed with FBP and TVS combined with diagonally relaxed orthogonal projections (TVS-DROP). A total variation minimization (TVM) filter was also applied to the image reconstructed with FBP (FBP-TVM). Quantitative accuracy and variance of proton relative stopping power (RSP) derived from each image set was assessed. Mean RSPs were comparable with each image; however, the standard deviation of pixel values with TVS-DROP was reduced by a factor of 0.44 compared with the FBP image and a factor of 0.66 when compared with the FBP-TVM image. Proton doses calculated with the TVS-DROP image set were also better able to predict a reference dose distribution when compared with the FBP and FBP-TVM image sets. The study demonstrated the potential advantages of TVS-DROP as an image reconstruction method for DECT applied to proton therapy treatment planning.

  4. Distributed approximation of Pareto surfaces in multicriteria radiation therapy treatment planning.

    Science.gov (United States)

    Bokrantz, Rasmus

    2013-06-07

    We consider multicriteria radiation therapy treatment planning by navigation over the Pareto surface, implemented by interpolation between discrete treatment plans. Current state of the art for calculation of a discrete representation of the Pareto surface is to sandwich this set between inner and outer approximations that are updated one point at a time. In this paper, we generalize this sequential method to an algorithm that permits parallelization. The principle of the generalization is to apply the sequential method to an approximation of an inexpensive model of the Pareto surface. The information gathered from the model is sub-sequently used for the calculation of points from the exact Pareto surface, which are processed in parallel. The model is constructed according to the current inner and outer approximations, and given a shape that is difficult to approximate, in order to avoid that parts of the Pareto surface are incorrectly disregarded. Approximations of comparable quality to those generated by the sequential method are demonstrated when the degree of parallelization is up to twice the number of dimensions of the objective space. For practical applications, the number of dimensions is typically at least five, so that a speed-up of one order of magnitude is obtained.

  5. Fast voxel and polygon ray-tracing algorithms in intensity modulated radiation therapy treatment planning.

    Science.gov (United States)

    Fox, Christopher; Romeijn, H Edwin; Dempsey, James F

    2006-05-01

    We present work on combining three algorithms to improve ray-tracing efficiency in radiation therapy dose computation. The three algorithms include: An improved point-in-polygon algorithm, incremental voxel ray tracing algorithm, and stereographic projection of beamlets for voxel truncation. The point-in-polygon and incremental voxel ray-tracing algorithms have been used in computer graphics and nuclear medicine applications while the stereographic projection algorithm was developed by our group. These algorithms demonstrate significant improvements over the current standard algorithms in peer reviewed literature, i.e., the polygon and voxel ray-tracing algorithms of Siddon for voxel classification (point-in-polygon testing) and dose computation, respectively, and radius testing for voxel truncation. The presented polygon ray-tracing technique was tested on 10 intensity modulated radiation therapy (IMRT) treatment planning cases that required the classification of between 0.58 and 2.0 million voxels on a 2.5 mm isotropic dose grid into 1-4 targets and 5-14 structures represented as extruded polygons (a.k.a. Siddon prisms). Incremental voxel ray tracing and voxel truncation employing virtual stereographic projection was tested on the same IMRT treatment planning cases where voxel dose was required for 230-2400 beamlets using a finite-size pencil-beam algorithm. Between a 100 and 360 fold cpu time improvement over Siddon's method was observed for the polygon ray-tracing algorithm to perform classification of voxels for target and structure membership. Between a 2.6 and 3.1 fold reduction in cpu time over current algorithms was found for the implementation of incremental ray tracing. Additionally, voxel truncation via stereographic projection was observed to be 11-25 times faster than the radial-testing beamlet extent approach and was further improved 1.7-2.0 fold through point-classification using the method of translation over the cross product technique.

  6. Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Paulus, Daniel H., E-mail: daniel.paulus@imp.uni-erlangen.de [Institute of Medical Physics, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen 91052 (Germany); Thorwath, Daniela [Section for Biomedical Physics, University Hospital for Radiation Oncology, Eberhard Karls University Tübingen, Tübingen 72076 (Germany); Schmidt, Holger [Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tübingen, Tübingen 72076 (Germany); Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Tübingen 72076 (Germany); Quick, Harald H. [Institute of Medical Physics, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen 91052 (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen 45141 (Germany); High Field and Hybrid MR-Imaging, University Hospital Essen, Essen 45147 (Germany)

    2014-07-15

    Purpose: Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning devices intended for PET/MR hybrid imaging are introduced and tested toward PET/MR compatibility and image quality. Methods: A prototype flat RT table overlay and two radiofrequency (RF) coil holders that each fix one flexible body matrix RF coil for RT head/neck imaging have been evaluated within this study. MR image quality with the RT head setup was compared to the actual PET/MR setup with a dedicated head RF coil. PET photon attenuation and CT-based attenuation correction (AC) of the hardware components has been quantitatively evaluated by phantom scans. Clinical application of the new RT setup in PET/MR imaging was evaluated in anin vivo study. Results: The RT table overlay and RF coil holders are fully PET/MR compatible. MR phantom and volunteer imaging with the RT head setup revealed high image quality, comparable to images acquired with the dedicated PET/MR head RF coil, albeit with 25% reduced SNR. Repositioning accuracy of the RF coil holders was below 1 mm. PET photon attenuation of the RT table overlay was calculated to be 3.8% and 13.8% for the RF coil holders. With CT-based AC of the devices, the underestimation error was reduced to 0.6% and 0.8%, respectively. Comparable results were found within the patient study. Conclusions: The newly designed RT devices for hybrid PET/MR imaging are PET and MR compatible. The mechanically rigid design and the reproducible positioning allow for straightforward CT-based AC. The systematic evaluation within this study provides the

  7. Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning.

    Science.gov (United States)

    Paulus, Daniel H; Thorwath, Daniela; Schmidt, Holger; Quick, Harald H

    2014-07-01

    Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning devices intended for PET/MR hybrid imaging are introduced and tested toward PET/MR compatibility and image quality. A prototype flat RT table overlay and two radiofrequency (RF) coil holders that each fix one flexible body matrix RF coil for RT head/neck imaging have been evaluated within this study. MR image quality with the RT head setup was compared to the actual PET/MR setup with a dedicated head RF coil. PET photon attenuation and CT-based attenuation correction (AC) of the hardware components has been quantitatively evaluated by phantom scans. Clinical application of the new RT setup in PET/MR imaging was evaluated in anin vivo study. The RT table overlay and RF coil holders are fully PET/MR compatible. MR phantom and volunteer imaging with the RT head setup revealed high image quality, comparable to images acquired with the dedicated PET/MR head RF coil, albeit with 25% reduced SNR. Repositioning accuracy of the RF coil holders was below 1 mm. PET photon attenuation of the RT table overlay was calculated to be 3.8% and 13.8% for the RF coil holders. With CT-based AC of the devices, the underestimation error was reduced to 0.6% and 0.8%, respectively. Comparable results were found within the patient study. The newly designed RT devices for hybrid PET/MR imaging are PET and MR compatible. The mechanically rigid design and the reproducible positioning allow for straightforward CT-based AC. The systematic evaluation within this study provides the technical basis for the clinical

  8. High resolution X-ray fluorescence imaging for a microbeam radiation therapy treatment planning system

    Science.gov (United States)

    Chtcheprov, Pavel; Inscoe, Christina; Burk, Laurel; Ger, Rachel; Yuan, Hong; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) uses an array of high-dose, narrow (~100 μm) beams separated by a fraction of a millimeter to treat various radio-resistant, deep-seated tumors. MRT has been shown to spare normal tissue up to 1000 Gy of entrance dose while still being highly tumoricidal. Current methods of tumor localization for our MRT treatments require MRI and X-ray imaging with subject motion and image registration that contribute to the measurement error. The purpose of this study is to develop a novel form of imaging to quickly and accurately assist in high resolution target positioning for MRT treatments using X-ray fluorescence (XRF). The key to this method is using the microbeam to both treat and image. High Z contrast media is injected into the phantom or blood pool of the subject prior to imaging. Using a collimated spectrum analyzer, the region of interest is scanned through the MRT beam and the fluorescence signal is recorded for each slice. The signal can be processed to show vascular differences in the tissue and isolate tumor regions. Using the radiation therapy source as the imaging source, repositioning and registration errors are eliminated. A phantom study showed that a spatial resolution of a fraction of microbeam width can be achieved by precision translation of the mouse stage. Preliminary results from an animal study showed accurate iodine profusion, confirmed by CT. The proposed image guidance method, using XRF to locate and ablate tumors, can be used as a fast and accurate MRT treatment planning system.

  9. Imaging method and system for verification of a treatment plan in hadron therapy

    NARCIS (Netherlands)

    Sevastyuk, Oksana; van Goethem, Marc-Jan; Brandenburg, Sijtze

    2016-01-01

    An imaging method and system for verification of a treatment plan (A). A phantom volume (V) is provided consisting of a material (10m) having dose absorbing properties similar to a biological tissue according to the treatment plan (A). Dose parameters (Q) of a hadron beam (B) are set according to

  10. SU-E-T-337: Treatment Planning Study of Craniospinal Irradiation with Spot Scanning Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Tasson, A; Beltran, C; Laack, N; Childs, S; Tryggestad, E; Whitaker, T [Mayo Clinic, Rochester, MN (United States)

    2014-06-01

    Purpose: To develop a treatment planning technique that achieves optimal robustness against systematic position and range uncertainties, and interfield position errors for craniospinal irradiation (CSI) using spot scanning proton radiotherapy. Methods: Eighteen CSI patients who had previously been treated using photon radiation were used for this study. Eight patients were less than 10 years old. The prescription dose was 23.4Gy in 1.8Gy fractions. Two different field arrangement types were investigated: 1 posterior field per isocenter and 2 posterior oblique fields per isocenter. For each field type, two delivery configurations were used: 5cm bolus attached to the treatment table and a 4.5cm range shifter located inside the nozzle. The target for each plan was the whole brain and thecal sac. For children under the age of 10, all plan types were repeated with an additional dose of 21Gy prescribed to the vertebral bodies. Treatment fields were matched by stepping down the dose in 10% increments over 9cm. Robustness against 3% and 3mm uncertainties, as well as a 3mm inter-field error was analyzed. Dose coverage of the target and critical structure sparing for each plan type will be considered. Ease of planning and treatment delivery was also considered for each plan type. Results: The mean dose volume histograms show that the bolus plan with posterior beams gave the best overall plan, and all proton plans were comparable to or better than the photon plans. The plan type that was the most robust against the imposed uncertainties was also the bolus plan with posterior beams. This is also the plan configuration that is the easiest to deliver and plan. Conclusion: The bolus plan with posterior beams achieved optimal robustness against systematic position and range uncertainties, as well as inter-field position errors.

  11. SU-E-T-28: A Treatment Planning Comparison of Volumetric Modulated Arc Therapy Vs. Proton Therapy for Post-Mastectomy Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, M; Zhang, R; Sanders, M; Newhauser, W [Louisiana State University, Baton Rouge, LA (United States)

    2014-06-01

    Purpose: The delivery of post-mastectomy radiotherapy (PMRT) can be challenging for patients with left-sided breast cancer due to the PTV size and proximity to critical organs. This study investigates the use of protons for PMRT in a clinically-representative cohort of patients, and quantitatively compares volumetric modulated arc therapy (VMAT) to proton therapy to have an evidence-based rationale for selecting a treatment modality for these patients. Methods: Eight left-sided PMRT patients previously treated at our clinic with VMAT were identified for the study. PTVs included the chest wall and regional lymph nodes. Passively scattered (PS) and intensity modulated proton therapy (IMPT) plans were constructed using the Eclipse proton planning system. The resulting plans were compared to the original VMAT plan on the basis of PTV coverage; dose homogeneity index (DHI) and conformity index (CI); dose to organs at risk (OAR); tumor control probability (TCP), normal tissue complication probability (NTCP) and secondary cancer complication probability (SCCP). Differences were tested for significance using the paired Student's t-test (p<0.01). Results: All modalities produced clinically acceptable PMRT plans. The comparison demonstrated proton treatment plans provide significantly lower NTCP values for the heart and the lung while maintaining significantly better CI and DHI. At a prescribed dose of 50.4 Gy (RBE) in the PTV, the calculated mean NTCP value for the patients decreased from 1.3% to 0.05% for the whole heart (cardiac mortality) and from 3.8% to 1.1% for the lungs (radiation pneumonitis) for both proton therapy plans from VMAT plans. Both proton modalities showed a significantly lower SCCP for the contralateral breast compared to VMAT. Conclusion: All three plans (VMAT, PS, and IMPT) provide acceptable treatment plans for PMRT. However, proton therapy shows a significant advantage over VMAT with regards to sparing OARs and may be more advantageous for

  12. Full Monte Carlo-Based Biologic Treatment Plan Optimization System for Intensity Modulated Carbon Ion Therapy on Graphics Processing Unit.

    Science.gov (United States)

    Qin, Nan; Shen, Chenyang; Tsai, Min-Yu; Pinto, Marco; Tian, Zhen; Dedes, Georgios; Pompos, Arnold; Jiang, Steve B; Parodi, Katia; Jia, Xun

    2018-01-01

    One of the major benefits of carbon ion therapy is enhanced biological effectiveness at the Bragg peak region. For intensity modulated carbon ion therapy (IMCT), it is desirable to use Monte Carlo (MC) methods to compute the properties of each pencil beam spot for treatment planning, because of their accuracy in modeling physics processes and estimating biological effects. We previously developed goCMC, a graphics processing unit (GPU)-oriented MC engine for carbon ion therapy. The purpose of the present study was to build a biological treatment plan optimization system using goCMC. The repair-misrepair-fixation model was implemented to compute the spatial distribution of linear-quadratic model parameters for each spot. A treatment plan optimization module was developed to minimize the difference between the prescribed and actual biological effect. We used a gradient-based algorithm to solve the optimization problem. The system was embedded in the Varian Eclipse treatment planning system under a client-server architecture to achieve a user-friendly planning environment. We tested the system with a 1-dimensional homogeneous water case and 3 3-dimensional patient cases. Our system generated treatment plans with biological spread-out Bragg peaks covering the targeted regions and sparing critical structures. Using 4 NVidia GTX 1080 GPUs, the total computation time, including spot simulation, optimization, and final dose calculation, was 0.6 hour for the prostate case (8282 spots), 0.2 hour for the pancreas case (3795 spots), and 0.3 hour for the brain case (6724 spots). The computation time was dominated by MC spot simulation. We built a biological treatment plan optimization system for IMCT that performs simulations using a fast MC engine, goCMC. To the best of our knowledge, this is the first time that full MC-based IMCT inverse planning has been achieved in a clinically viable time frame. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Randomized Algorithms For High Quality Treatment Planning in Volumetric Modulated Arc Therapy

    CERN Document Server

    Yang, Yu; Wen, Zaiwen

    2015-01-01

    In recent years, volumetric modulated arc therapy (VMAT) has been becoming a more and more important radiation technique widely used in clinical application for cancer treatment. One of the key problems in VMAT is treatment plan optimization, which is complicated due to the constraints imposed by the involved equipments. In this paper, we consider a model with four major constraints: the bound on the beam intensity, an upper bound on the rate of the change of the beam intensity, the moving speed of leaves of the multi-leaf collimator (MLC) and its directional-convexity. We solve the model by a two-stage algorithm: performing minimization with respect to the shapes of the aperture and the beam intensities alternatively. Specifically, the shapes of the aperture are obtained by a greedy algorithm whose performance is enhanced by random sampling in the leaf pairs with a decremental rate. The beam intensity is optimized using a gradient projection method with non-monotonic line search. We further improve the propo...

  14. 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.

  15. Spot scanning proton therapy for malignancies of the base of skull: treatment planning, acute toxicities, and preliminary clinical outcomes.

    Science.gov (United States)

    Grosshans, David R; Zhu, X Ronald; Melancon, Adam; Allen, Pamela K; Poenisch, Falk; Palmer, Matthew; McAleer, Mary Frances; McGovern, Susan L; Gillin, Michael; DeMonte, Franco; Chang, Eric L; Brown, Paul D; Mahajan, Anita

    2014-11-01

    To describe treatment planning techniques and early clinical outcomes in patients treated with spot scanning proton therapy for chordoma or chondrosarcoma of the skull base. From June 2010 through August 2011, 15 patients were treated with spot scanning proton therapy for chordoma (n=10) or chondrosarcoma (n=5) at a single institution. Toxicity was prospectively evaluated and scored weekly and at all follow-up visits according to Common Terminology Criteria for Adverse Events, version 3.0. Treatment planning techniques and dosimetric data were recorded and compared with those of passive scattering plans created with clinically applicable dose constraints. Ten patients were treated with single-field-optimized scanning beam plans and 5 with multifield-optimized intensity modulated proton therapy. All but 2 patients received a simultaneous integrated boost as well. The mean prescribed radiation doses were 69.8 Gy (relative biological effectiveness [RBE]; range, 68-70 Gy [RBE]) for chordoma and 68.4 Gy (RBE) (range, 66-70) for chondrosarcoma. In comparison with passive scattering plans, spot scanning plans demonstrated improved high-dose conformality and sparing of temporal lobes and brainstem. Clinically, the most common acute toxicities included fatigue (grade 2 for 2 patients, grade 1 for 8 patients) and nausea (grade 2 for 2 patients, grade 1 for 6 patients). No toxicities of grades 3 to 5 were recorded. At a median follow-up time of 27 months (range, 13-42 months), 1 patient had experienced local recurrence and a second developed distant metastatic disease. Two patients had magnetic resonance imaging-documented temporal lobe changes, and a third patient developed facial numbness. No other subacute or late effects were recorded. In comparison to passive scattering, treatment plans for spot scanning proton therapy displayed improved high-dose conformality. Clinically, the treatment was well tolerated, and with short-term follow-up, disease control rates and toxicity

  16. 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

  17. Neurocognition and quality of life after reinitiating antiretroviral therapy in children randomized to planned treatment interruption

    NARCIS (Netherlands)

    Ananworanich, Jintanat; Melvin, Diane; Amador, Jose T. R.; Childs, Tristan; Medin, Gabriela; Boscolo, Valentina; Compagnucci, Alexandra; Kanjanavanit, Suparat; Montero, Samuel; Gibb, Diana M.; Aboulker, J. -P.; Babiker, A.; Belfrage, E.; Bernardi, S.; Bologna, R.; Burger, D.; Butler, K.; Castelli-Gattinara, G.; Castro, H.; Clayden, P.; Compagnucci, A.; Cressey, T.; Darbyshire, J. H.; Debré, M.; de Groot, R.; della Negra, M.; Di Biagio, A.; de Rossi, A.; Duicelescu, D.; Faye, A.; Giaquinto, C.; Giacomet, V.; Gibb, D. M.; Grosch-Wörner, I.; Hainault, M.; Klein, N.; Lallemant, M.; Levy, J.; Lyall, H.; Marczynska, M.; Marques, L.; Mardarescu, M.; Mellado Peña, M. J.; Nadal, D.; Nastouli, E.; Naver, L.; Niehues, T.; Peckham, C.; Pillay, D.; Popieska, J.; Ramos Amador, J. T.; Rojo Conejo, P.; Rosado, L.; Rosso, R.; Rudin, C.; Scherpbier, H. J.; Sharland, M.; Stevanovic, M.; Thorne, C.; Tovo, P. A.; Tudor-Williams, G.; Turkova, A.; Valerius, N.; Volokha, A.; Walker, A. S.; Welch, S.; Wintergerst, U.; Aboulker, J. P.; Burger, D. M.; Green, H.; Harper, L.; Mofenson, L.; Moye, J.; Saïdi, Y.; Cressey, T. R.; Jacqz-Aigrain, E.; Khoo, S.; Regazzi, M.; Tréluyer, J. M.; Ngo-Giang-Huong, N.; Muñoz Fernandez, M. A.; Hill, C.; Lepage, P.; Pozniak, A.; Vella, S.; Chêne, G.; Vesikari, T.; Hadjou, G.; Léonardo, S.; Riault, Y.; Bleier, J.; Buck, L.; Duong, T.; Farrelly, L.; Forcat, S.; Harrison, L.; Horton, J.; Johnson, D.; Montero, S.; Taylor, C.; Chalermpantmetagul, S.; Peongjakta, R.; Khamjakkaew, W.; Than-in-at, K.; Chailert, S.; Jourdain, G.; Le Coeur, S.; Floret, D.; Costanzo, P.; Le Thi, T. T.; Monpoux, F.; Mellul, S.; Caranta, I.; Boudjoudi, N.; Firtion, G.; Denon, M.; Charlemaine, E.; Picard, F.; Hellier, E.; Heuninck, C.; Damond, F.; Alexandre, G.; Tricoire, J.; Antras, M.; Lachendowier, C.; Nicot, F.; Krivine, A.; Rivaux, D.; Notheis, G.; Strotmann, G.; Schlieben, S.; Rampon, O.; Boscolo, V.; Zanchetta, M.; Ginocchio, F.; Viscoli, C.; Martino, A.; Pontrelli, G.; Baldassar, S.; Concato, C.; Mazza, A.; Rossetti, G.; Dobosz, S.; Oldakowska, A.; Popielska, J.; Kaflik, M.; Stanczak, J.; Stanczack, G.; Dyda, T.; Kruk, M.; González Tomé, M. I.; Delgado García, R.; Fernandez Gonzalez, M. T.; Medin, G.; Mellado Peña, M. José; Martín Fontelos, P.; Garcia Mellado, M. I.; Medina, A. F.; Ascencion, B.; Garcia Bermejo, I.; Navarro Gomez, D. M. L.; Saavedra, J.; Prieto, C.; Jimenez, J. L.; Muñoz-Fernandez, M. A.; Garcia Torre, A.; de José Gómez, M. I.; García Rodriguez, M. C.; Moreno Pérez, D.; Núñez Cuadros, E.; Asensi-Botet, F.; Otero Reigada, C.; Pérez Tamarit, M. D.; Vilalta, R.; Molina Moreno, J. M.; Rainer, Truninger; Schupbach, J.; Rutishauser, M.; Bunupuradah, T.; Butterworth, O.; Phasomsap, C.; Prasitsuebsai, W.; Chuanjaroen, T.; Jupimai, T.; Ubolyam, S.; Phanuphak, P.; Puthanakit, T.; Pancharoen, C.; Mai, Chaing; Kanjanavanit, S.; Namwong, T.; Punsakoon, W.; Payakachat, S.; Chutima, D.; Raksasang, M.; Foster, C.; Hamadache, D.; Campbell, S.; Newbould, C.; Monrose, C.; Abdulla, A.; Walley, A.; Melvin, D.; Patel, D.; Kaye, S.; Seery, P.; Rankin, A.; Wildfire, A.; Novelli, V.; Shingadia, D.; Moshal, K.; Flynn, J.; Clapson, M.; Allen, A.; Spencer, L.; Rackstraw, C.; Ward, B.; Parkes, K.; Depala, M.; Jacobsen, M.; Poulsom, H.; Barkley, L.; Miah, J.; Lurie, P.; Keane, C.; McMaster, P.; Phipps, M.; Orendi, J.; Farmer, C.; Liebeschuetz, S.; Sodeinde, O.; Wong, S.; Bostock, V.; Heath, Y.; Scott, S.; Gandhi, K.; Lewis, P.; Daglish, J.; Miles, K.; Summerhill, L.; Subramaniam, B.; Weiner, L.; Famiglietti, M.; Rana, S.; Yu, P.; Roa, J.; Puga, A.; Haerry, A.

    2016-01-01

    Objective: Understanding the effects of antiretroviral treatment (ART) interruption on neurocognition and quality of life (QoL) are important for managing unplanned interruptions and planned interruptions in HIV cure research. Design: Children previously randomized to continuous (continuous ART, n =

  18. The role of patient-based treatment planning in peptide receptor radionuclide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hardiansyah, Deni; Attarwala, Ali Asgar [Heidelberg University, Medical Radiation Physics/Radiation Protection, Universitaetsmedizin Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Universitaetsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Department of Radiation Oncology, Mannheim (Germany); Maass, Christian; Glatting, Gerhard [Heidelberg University, Medical Radiation Physics/Radiation Protection, Universitaetsmedizin Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Mueller, Berthold [University Hospital, RWTH Aachen University, Klinik fuer Nuklearmedizin, Aachen (Germany); Kletting, Peter [Universitaet Ulm, Klinik fuer Nuklearmedizin, Ulm (Germany); Mottaghy, Felix M. [University Hospital, RWTH Aachen University, Klinik fuer Nuklearmedizin, Aachen (Germany); Maastricht University Medical Center (MUMC+), Department of Nuclear Medicine, Maastricht (Netherlands)

    2016-05-15

    Accurate treatment planning is recommended in peptide-receptor radionuclide therapy (PRRT) to minimize the toxicity to organs at risk while maximizing tumor cell sterilization. The aim of this study was to quantify the effect of different degrees of individualization on the prediction accuracy of individual therapeutic biodistributions in patients with neuroendocrine tumors (NETs). A recently developed physiologically based pharmacokinetic (PBPK) model was fitted to the biokinetic data of 15 patients with NETs after pre-therapeutic injection of {sup 111}In-DTPAOC. Mathematical phantom patients (MPP) were defined using the assumed true (true MPP), mean (MPP 1A) and median (MPP 1B) parameter values of the patient group. Alterations of the degree of individualization were introduced to both mean and median patients by including patient-specific information as a priori knowledge: physical parameters and hematocrit (MPP 2A/2B). Successively, measurable individual biokinetic parameters were added: tumor volume V{sub tu} (MPP 3A/3B), glomerular filtration rate GFR (MPP 4A/4B), and tumor perfusion f{sub tu} (MPP 5A/5B). Furthermore, parameters of MPP 5A/5B and a simulated {sup 68}Ga-DOTATATE PET measurement 60 min p.i. were used together with the population values used as Bayesian parameters (MPP 6A/6B). Therapeutic biodistributions were simulated assuming an infusion of {sup 90}Y-DOTATATE (3.3 GBq) over 30 min to all MPPs. Time-integrated activity coefficients were predicted for all MPPs and compared to the true MPPs for each patient in tumor, kidneys, spleen, liver, remainder, and whole body to obtain the relative differences RD. The large RD values of MPP 1A [RD{sub tumor} = (625 ± 1266)%, RD{sub kidneys} = (11 ± 38)% ], and MPP 1B [RD{sub tumor} = (197 ± 505)%, RD{sub kidneys} = (11 ± 39)% ] demonstrate that individual treatment planning is needed due to large physiological differences between patients. Although addition of individual patient parameters reduced the

  19. Treatment planning with intensity modulated particle therapy for multiple targets in stage IV non-small cell lung cancer

    Science.gov (United States)

    Anderle, Kristjan; Stroom, Joep; Vieira, Sandra; Pimentel, Nuno; Greco, Carlo; Durante, Marco; Graeff, Christian

    2018-01-01

    Intensity modulated particle therapy (IMPT) can produce highly conformal plans, but is limited in advanced lung cancer patients with multiple lesions due to motion and planning complexity. A 4D IMPT optimization including all motion states was expanded to include multiple targets, where each target (isocenter) is designated to specific field(s). Furthermore, to achieve stereotactic treatment planning objectives, target and OAR weights plus objective doses were automatically iteratively adapted. Finally, 4D doses were calculated for different motion scenarios. The results from our algorithm were compared to clinical stereotactic body radiation treatment (SBRT) plans. The study included eight patients with 24 lesions in total. Intended dose regimen for SBRT was 24 Gy in one fraction, but lower fractionated doses had to be delivered in three cases due to OAR constraints or failed plan quality assurance. The resulting IMPT treatment plans had no significant difference in target coverage compared to SBRT treatment plans. Average maximum point dose and dose to specific volume in OARs were on average 65% and 22% smaller with IMPT. IMPT could also deliver 24 Gy in one fraction in a patient where SBRT was limited due to the OAR vicinity. The developed algorithm shows the potential of IMPT in treatment of multiple moving targets in a complex geometry.

  20. Benchmarking of a treatment planning system for spot scanning proton therapy: Comparison and analysis of robustness to setup errors of photon IMRT and proton SFUD treatment plans of base of skull meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Harding, R., E-mail: ruth.harding2@wales.nhs.uk [St James’s Institute of Oncology, Medical Physics and Engineering, Leeds LS9 7TF, United Kingdomand Abertawe Bro Morgannwg University Health Board, Medical Physics and Clinical Engineering, Swansea SA2 8QA (United Kingdom); Trnková, P.; Lomax, A. J. [Paul Scherrer Institute, Centre for Proton Therapy, Villigen 5232 (Switzerland); Weston, S. J.; Lilley, J.; Thompson, C. M.; Cosgrove, V. P. [St James’s Institute of Oncology, Medical Physics and Engineering, Leeds LS9 7TF (United Kingdom); Short, S. C. [Leeds Institute of Molecular Medicine, Oncology and Clinical Research, Leeds LS9 7TF, United Kingdomand St James’s Institute of Oncology, Oncology, Leeds LS9 7TF (United Kingdom); Loughrey, C. [St James’s Institute of Oncology, Oncology, Leeds LS9 7TF (United Kingdom); Thwaites, D. I. [St James’s Institute of Oncology, Medical Physics and Engineering, Leeds LS9 7TF, United Kingdomand Institute of Medical Physics, School of Physics, University of Sydney, Sydney NSW 2006 (Australia)

    2014-11-01

    Purpose: Base of skull meningioma can be treated with both intensity modulated radiation therapy (IMRT) and spot scanned proton therapy (PT). One of the main benefits of PT is better sparing of organs at risk, but due to the physical and dosimetric characteristics of protons, spot scanned PT can be more sensitive to the uncertainties encountered in the treatment process compared with photon treatment. Therefore, robustness analysis should be part of a comprehensive comparison between these two treatment methods in order to quantify and understand the sensitivity of the treatment techniques to uncertainties. The aim of this work was to benchmark a spot scanning treatment planning system for planning of base of skull meningioma and to compare the created plans and analyze their robustness to setup errors against the IMRT technique. Methods: Plans were produced for three base of skull meningioma cases: IMRT planned with a commercial TPS [Monaco (Elekta AB, Sweden)]; single field uniform dose (SFUD) spot scanning PT produced with an in-house TPS (PSI-plan); and SFUD spot scanning PT plan created with a commercial TPS [XiO (Elekta AB, Sweden)]. A tool for evaluating robustness to random setup errors was created and, for each plan, both a dosimetric evaluation and a robustness analysis to setup errors were performed. Results: It was possible to create clinically acceptable treatment plans for spot scanning proton therapy of meningioma with a commercially available TPS. However, since each treatment planning system uses different methods, this comparison showed different dosimetric results as well as different sensitivities to setup uncertainties. The results confirmed the necessity of an analysis tool for assessing plan robustness to provide a fair comparison of photon and proton plans. Conclusions: Robustness analysis is a critical part of plan evaluation when comparing IMRT plans with spot scanned proton therapy plans.

  1. Automated Volumetric Modulated Arc Therapy Treatment Planning for Stage III Lung Cancer: How Does It Compare With Intensity-Modulated Radio Therapy?

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Enzhuo M. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Joe Y.; Liao Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Xia Tingyi [Department of Radiation Oncology, Beijing 301 Hospital, Beijing (China); Yuan Zhiyong [Department of Radiation Oncology, Tianjin Medical University Cancer Hospital and Institute, Tianjin (China); Liu Hui [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Zhongshan University Hospital, Guangzhou (China); Li, Xiaoqiang; Wages, Cody A.; Mohan, Radhe [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhang Xiaodong, E-mail: xizhang@mdanderson.org [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-09-01

    Purpose: To compare the quality of volumetric modulated arc therapy (VMAT) or intensity-modulated radiation therapy (IMRT) plans generated by an automated inverse planning system with that of dosimetrist-generated IMRT treatment plans for patients with stage III lung cancer. Methods and Materials: Two groups of 8 patients with stage III lung cancer were randomly selected. For group 1, the dosimetrists spent their best effort in designing IMRT plans to compete with the automated inverse planning system (mdaccAutoPlan); for group 2, the dosimetrists were not in competition and spent their regular effort. Five experienced radiation oncologists independently blind-reviewed and ranked the three plans for each patient: a rank of 1 was the best and 3 was the worst. Dosimetric measures were also performed to quantitatively evaluate the three types of plans. Results: Blind rankings from different oncologists were generally consistent. For group 1, the auto-VMAT, auto-IMRT, and manual IMRT plans received average ranks of 1.6, 2.13, and 2.18, respectively. The auto-VMAT plans in group 1 had 10% higher planning tumor volume (PTV) conformality and 24% lower esophagus V70 (the volume receiving 70 Gy or more) than the manual IMRT plans; they also resulted in more than 20% higher complication-free tumor control probability (P+) than either type of IMRT plans. The auto- and manual IMRT plans in this group yielded generally comparable dosimetric measures. For group 2, the auto-VMAT, auto-IMRT, and manual IMRT plans received average ranks of 1.55, 1.75, and 2.75, respectively. Compared to the manual IMRT plans in this group, the auto-VMAT plans and auto-IMRT plans showed, respectively, 17% and 14% higher PTV dose conformality, 8% and 17% lower mean lung dose, 17% and 26% lower mean heart dose, and 36% and 23% higher P+. Conclusions: mdaccAutoPlan is capable of generating high-quality VMAT and IMRT treatment plans for stage III lung cancer. Manual IMRT plans could achieve quality

  2. Comparison of dose calculation algorithms for treatment planning in external photon beam therapy for clinical situations

    DEFF Research Database (Denmark)

    Knöös, Tommy; Wieslander, Elinore; Cozzi, Luca

    2006-01-01

    A study of the performance of five commercial radiotherapy treatment planning systems (TPSs) for common treatment sites regarding their ability to model heterogeneities and scattered photons has been performed. The comparison was based on CT information for prostate, head and neck, breast and lun...

  3. Treatment planning of intensity modulated composite particle therapy with dose and linear energy transfer optimization

    Science.gov (United States)

    Inaniwa, Taku; Kanematsu, Nobuyuki; Noda, Koji; Kamada, Tadashi

    2017-06-01

    The biological effect of charged-particle beams depends on both dose and particle spectrum. As one of the physical quantities describing the particle spectrum of charged-particle beams, we considered the linear energy transfer (LET) throughout this study. We investigated a new therapeutic technique using two or more ion species in one treatment session, which we call an intensity modulated composite particle therapy (IMPACT), for optimizing the physical dose and dose-averaged LET distributions in a patient as its proof of principle. Protons and helium, carbon, and oxygen ions were considered as ion species for IMPACT. For three cubic targets of 4  ×  4  ×  4, 8  ×  8  ×  8, and 12  ×  12  ×  12 cm3, defined at the center of the water phantom of 20  ×  20  ×  20 cm3, we made IMPACT plans of two composite fields with opposing and orthogonal geometries. The prescribed dose to the target was fixed at 1 Gy, while the prescribed LET to the target was varied from 1 keV µm-1 to 120 keV µm-1 to investigate the range of LET valid for prescription. The minimum and maximum prescribed LETs, (L T_min, L T_max), by the opposing-field geometry, were (3 keV µm-1, 115 keV µm-1), (2 keV µm-1, 84 keV µm-1),and (2 keV µm-1, 66 keV µm-1), while those by the orthogonal-field geometry were (8 keV µm-1, 98 keV µm-1), (7 keV µm-1, 72 keV µm-1), and (8 keV µm-1, 57 keV µm-1) for the three targets, respectively. To show the proof of principle of IMPACT in a clinical situation, we made IMPACT plans for a prostate case. In accordance with the prescriptions, the LETs in prostate, planning target volume (PTV), and rectum could be adjusted at 80 keV µm-1, at 50 keV µm-1, and below 30 keV µm-1, respectively, while keeping the dose to the PTV at 2 Gy uniformly. IMPACT enables the optimization of the dose and the LET distributions in a patient, which will maximize the

  4. 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...

  5. Continued Development Of An Inexpensive Simulator Based CT Scanner For Radiation Therapy Treatment Planning

    Science.gov (United States)

    Peschmann, K. R.; Parker, D. L.; Smith, V.

    1982-11-01

    An abundant number of different CT scanner models has been developed in the past ten years, meeting increasing standards of performance. From the beginning they remained a comparatively expensive piece of equipment. This is due not only to their technical complexity but is also due to the difficulties involved in assessing "true" specifications (avoiding "overde-sign"). Our aim has been to provide, for Radiation Therapy Treatment Planning, a low cost CT scanner system featuring large freedom in patient positioning. We have taken advantage of the concurrent tremendously increased amount of knowledge and experience in the technical area of CT1 . By way of extensive computer simulations we gained confidence that an inexpensive C-arm simulator gantry and a simple one phase-two pulse generator in connection with a standard x-ray tube could be used, without sacrificing image quality. These components have been complemented by a commercial high precision shaft encoder, a simple and effective fan beam collimator, a high precision, high efficiency, luminescence crystal-silicon photodiode detector with 256 channels, low noise electronic preamplifier and sampling filter stages, a simplified data aquisition system furnished by Toshiba/ Analogic and an LSI 11/23 microcomputer plus data storage disk as well as various smaller interfaces linking the electrical components. The quality of CT scan pictures of phantoms,performed by the end of last year confirmed that this simple approach is working well. As a next step we intend to upgrade this system with an array processor in order to shorten recon-struction time to one minute per slice. We estimate that the system including this processor could be manufactured for a selling price of $210,000.

  6. Practical aspects of inverse-planned intensity-modulated radiation therapy for prostate cancer: a radiation treatment planner's perspective.

    Science.gov (United States)

    Parker, William; Patrocinio, Horacio

    2005-06-01

    From a radiation treatment planner perspective, in the treatment of prostate cancer, inverse-planned intensity-modulated radiation therapy (IMRT) differs considerably from conventional, conformal, and forward-planned IMRT. In this work we aim to discuss the rationale behind the use of inverse-planned IMRT for the treatment of prostate cancer, as well as some of the practical aspects, including the differences in planning strategies, dose fractionation and issues in plan evaluation. The primary motivation behind the use of inverse-planned IMRT for prostate cancer radiotherapy is to attempt further dose escalation while maintaining critical structure and healthy tissue sparing at an acceptable level. The sparing of normal tissues is largely dependent on the size of the planning target volume (PTV) defined, and if the PTV overlaps critical structures. Depending on how the PTV is defined it may be impossible to achieve the desired healthy tissue sparing even with IMRT. A second role for the use of IMRT in the treatment of prostate cancer may be to conform the isodose distribution to a complex PTV, such as one that includes the seminal vesicles or the pelvic lymph nodes in the treatment volume. Finally, inverse planned IMRT may be useful in the planning and delivery of simultaneous integrated boosts where different parts of the target structures receive different daily doses. This again has applications for the simultaneous treatment of pelvic lymph nodes with the prostate treatment volume, and presents interesting opportunities for hypo-fractionation. All of these options of course require careful plan evaluation with respect to isodose distributions and dose-volume constraints as well as the radiobiological consequences of using unconventional fractionation. IMRT seems to be the most effective modality for treating complex target geometries and for delivering simultaneous integrated boosts. In particular for prostate cancer, the simultaneous treatment of the prostate

  7. Advanced treatment planning using direct 4D optimisation for pencil-beam scanned particle therapy.

    Science.gov (United States)

    Bernatowicz, Kinga; Zhang, Ye; Perrin, Rosalind; Weber, Damien C; Lomax, Antony J

    2017-07-31

    We report on development of a new four-dimensional (4D) optimisation approach for scanned proton beams, which incorporates both irregular motion patterns and the delivery dynamics of the treatment machine into the plan optimiser. Furthermore, we assess the effectiveness of this technique to reduce dose to critical structures in proximity to moving targets, while maintaining effective target dose homogeneity and coverage. The proposed approach has been tested using both a simulated phantom and a clinical liver cancer case, and allows for realistic 4D calculations and optimisation using irregular breathing patterns extracted from e.g. 4DCT-MRI (4D computed tomography-magnetic resonance imaging). 4D dose distributions resulting from our 4D optimisation can achieve almost the same quality as static plans, independent of the studied geometry/anatomy or selected motion (regular and irregular). Additionally, current implementation of the 4D optimisation approach requires less than 3 min to find the solution for a single field planned on 4DCT of a liver cancer patient. Although 4D optimisation allows for realistic calculations using irregular breathing patterns, it is very sensitive to variations from the planned motion. Based on a sensitivity analysis, target dose homogeneity comparable to static plans (D5-D95  optimisation. As such, methods to robustly deliver 4D optimised plans employing 4D intensity-modulated delivery are discussed.

  8. Stereotactic intensity-modulated radiation therapy (IMRT) and inverse treatment planning for advanced pleural mesothelioma. Feasibility and initial results

    Energy Technology Data Exchange (ETDEWEB)

    Muenter, M.W.; Thilmann, C.; Hof, H.; Debus, J. [Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (dkfz), Heidelberg (Germany); Nill, S.; Hoess, A.; Partridge, M. [Dept. of Medical Physics, German Cancer Research Center (dkfz), Heidelberg (Germany); Haering, P. [Dept. of Central Dosimetry, German Cancer Research Center (dkfz), Heidelberg (Germany); Manegold, C. [Dept. of Medical Oncology/Internal Medicine, Thoraxklinik Heidelberg gGmbH, Heidelberg (Germany); Wannenmacher, M. [Dept. of Clinical Radiology, Univ. of Heidelberg, Heidelberg (Germany)

    2003-08-01

    Background and Purpose: Complex-shaped malignant pleural mesotheliomas (MPMs) with challenging volumes are extremely difficult to treat by conventional radiotherapy due to tolerance doses of the surrounding normal tissue. In a feasibility study, we evaluated if inversely planned stereotactic intensity-modulated radiation therapy (IMRT) could be applied in the treatment of MPM. Patients and Methods: Eight patients with unresectable lesions were treated after failure of chemotherapy. All patients were positioned using noninvasive patient fixation techniques which can be attached to the applied extracranial stereotactic system. Due to craniocaudal extension of the tumor, it was necessary to develop a special software attached to the inverse planning program KonRad, which can connect two inverse treatment plans and consider the applied dose of the first treatment plan in the area of the matchline of the second treatment plan. Results: Except for one patient, in whom radiotherapy was canceled due to abdominal metastasis, treatment could be completed in all patients and was well tolerated. Median survival after diagnosis was 20 months and after IMRT 6.5 months. Therefore, both the 1-year actuarial overall survival from the start of radiotherapy and the 2-year actuarial overall survival since diagnosis were 28%. IMRT did not result in clinically significant acute side effects. By using the described inverse planning software, over- or underdosage in the region of the field matchline could be prevented. Pure treatment time ranged between 10 and 21 min. Conclusion: This study showed that IMRT is feasible in advanced unresectable MPM. The presented possibilities of stereotactic IMRT in the treatment of MPM will justify the evaluation of IMRT in early-stage pleural mesothelioma combined with chemotherapy in a study protocol, in order to improve the outcome of these patients. Furthermore, dose escalation should be possible by using IMRT. (orig.)

  9. Spot Scanning Proton Therapy for Malignancies of the Base of Skull: Treatment Planning, Acute Toxicities, and Preliminary Clinical Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Grosshans, David R., E-mail: dgrossha@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhu, X. Ronald; Melancon, Adam [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Allen, Pamela K. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Poenisch, Falk; Palmer, Matthew [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); McAleer, Mary Frances; McGovern, Susan L. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gillin, Michael [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); DeMonte, Franco [Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Eric L. [Department of Radiation Oncology, University of Southern California Keck School of Medicine, Los Angeles, California (United States); Brown, Paul D.; Mahajan, Anita [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-11-01

    Purpose: To describe treatment planning techniques and early clinical outcomes in patients treated with spot scanning proton therapy for chordoma or chondrosarcoma of the skull base. Methods and Materials: From June 2010 through August 2011, 15 patients were treated with spot scanning proton therapy for chordoma (n=10) or chondrosarcoma (n=5) at a single institution. Toxicity was prospectively evaluated and scored weekly and at all follow-up visits according to Common Terminology Criteria for Adverse Events, version 3.0. Treatment planning techniques and dosimetric data were recorded and compared with those of passive scattering plans created with clinically applicable dose constraints. Results: Ten patients were treated with single-field-optimized scanning beam plans and 5 with multifield-optimized intensity modulated proton therapy. All but 2 patients received a simultaneous integrated boost as well. The mean prescribed radiation doses were 69.8 Gy (relative biological effectiveness [RBE]; range, 68-70 Gy [RBE]) for chordoma and 68.4 Gy (RBE) (range, 66-70) for chondrosarcoma. In comparison with passive scattering plans, spot scanning plans demonstrated improved high-dose conformality and sparing of temporal lobes and brainstem. Clinically, the most common acute toxicities included fatigue (grade 2 for 2 patients, grade 1 for 8 patients) and nausea (grade 2 for 2 patients, grade 1 for 6 patients). No toxicities of grades 3 to 5 were recorded. At a median follow-up time of 27 months (range, 13-42 months), 1 patient had experienced local recurrence and a second developed distant metastatic disease. Two patients had magnetic resonance imaging-documented temporal lobe changes, and a third patient developed facial numbness. No other subacute or late effects were recorded. Conclusions: In comparison to passive scattering, treatment plans for spot scanning proton therapy displayed improved high-dose conformality. Clinically, the treatment was well tolerated, and

  10. SU-G-TeP4-06: An Integrated Application for Radiation Therapy Treatment Plan Directives, Management, and Reporting

    Energy Technology Data Exchange (ETDEWEB)

    Matuszak, M; Anderson, C; Lee, C; Vineberg, K; Green, M; Younge, K; Moran, J; Mayo, C [University of Michigan, Ann Arbor, MI (United States)

    2016-06-15

    Purpose: With electronic medical records, patient information for the treatment planning process has become disseminated across multiple applications with limited quality control and many associated failure modes. We present the development of a single application with a centralized database to manage the planning process. Methods: The system was designed to replace current functionalities of (i) static directives representing the physician intent for the prescription and planning goals, localization information for delivery, and other information, (ii) planning objective reports, (iii) localization and image guidance documents and (iv) the official radiation therapy prescription in the medical record. Using the Eclipse Scripting Application Programming Interface, a plug-in script with an associated domain-specific SQL Server database was created to manage the information in (i)–(iv). The system’s user interface and database were designed by a team of physicians, clinical physicists, database experts, and software engineers to ensure usability and robustness for clinical use. Results: The resulting system has been fully integrated within the TPS via a custom script and database. Planning scenario templates, version control, approvals, and logic-based quality control allow this system to fully track and document the planning process as well as physician approval of tradeoffs while improving the consistency of the data. Multiple plans and prescriptions are supported along with non-traditional dose objectives and evaluation such as biologically corrected models, composite dose limits, and management of localization goals. User-specific custom views were developed for the attending physician review, physicist plan checks, treating therapists, and peer review in chart rounds. Conclusion: A method was developed to maintain cohesive information throughout the planning process within one integrated system by using a custom treatment planning management application that

  11. A unifying probabilistic Bayesian approach to derive electron density from MRI for radiation therapy treatment planning.

    Science.gov (United States)

    Gudur, Madhu Sudhan Reddy; Hara, Wendy; Le, Quynh-Thu; Wang, Lei; Xing, Lei; Li, Ruijiang

    2014-11-07

    MRI significantly improves the accuracy and reliability of target delineation in radiation therapy for certain tumors due to its superior soft tissue contrast compared to CT. A treatment planning process with MRI as the sole imaging modality will eliminate systematic CT/MRI co-registration errors, reduce cost and radiation exposure, and simplify clinical workflow. However, MRI lacks the key electron density information necessary for accurate dose calculation and generating reference images for patient setup. The purpose of this work is to develop a unifying method to derive electron density from standard T1-weighted MRI. We propose to combine both intensity and geometry information into a unifying probabilistic Bayesian framework for electron density mapping. For each voxel, we compute two conditional probability density functions (PDFs) of electron density given its: (1) T1-weighted MRI intensity, and (2) geometry in a reference anatomy, obtained by deformable image registration between the MRI of the atlas and test patient. The two conditional PDFs containing intensity and geometry information are combined into a unifying posterior PDF, whose mean value corresponds to the optimal electron density value under the mean-square error criterion. We evaluated the algorithm's accuracy of electron density mapping and its ability to detect bone in the head for eight patients, using an additional patient as the atlas or template. Mean absolute HU error between the estimated and true CT, as well as receiver operating characteristics for bone detection (HU > 200) were calculated. The performance was compared with a global intensity approach based on T1 and no density correction (set whole head to water). The proposed technique significantly reduced the errors in electron density estimation, with a mean absolute HU error of 126, compared with 139 for deformable registration (p = 2  ×  10(-4)), 283 for the intensity approach (p = 2  ×  10(-6)) and 282 without density

  12. Fred: a GPU-accelerated fast-Monte Carlo code for rapid treatment plan recalculation in ion beam therapy

    Science.gov (United States)

    Schiavi, A.; Senzacqua, M.; Pioli, S.; Mairani, A.; Magro, G.; Molinelli, S.; Ciocca, M.; Battistoni, G.; Patera, V.

    2017-09-01

    Ion beam therapy is a rapidly growing technique for tumor radiation therapy. Ions allow for a high dose deposition in the tumor region, while sparing the surrounding healthy tissue. For this reason, the highest possible accuracy in the calculation of dose and its spatial distribution is required in treatment planning. On one hand, commonly used treatment planning software solutions adopt a simplified beam-body interaction model by remapping pre-calculated dose distributions into a 3D water-equivalent representation of the patient morphology. On the other hand, Monte Carlo (MC) simulations, which explicitly take into account all the details in the interaction of particles with human tissues, are considered to be the most reliable tool to address the complexity of mixed field irradiation in a heterogeneous environment. However, full MC calculations are not routinely used in clinical practice because they typically demand substantial computational resources. Therefore MC simulations are usually only used to check treatment plans for a restricted number of difficult cases. The advent of general-purpose programming GPU cards prompted the development of trimmed-down MC-based dose engines which can significantly reduce the time needed to recalculate a treatment plan with respect to standard MC codes in CPU hardware. In this work, we report on the development of fred, a new MC simulation platform for treatment planning in ion beam therapy. The code can transport particles through a 3D voxel grid using a class II MC algorithm. Both primary and secondary particles are tracked and their energy deposition is scored along the trajectory. Effective models for particle-medium interaction have been implemented, balancing accuracy in dose deposition with computational cost. Currently, the most refined module is the transport of proton beams in water: single pencil beam dose-depth distributions obtained with fred agree with those produced by standard MC codes within 1-2% of the

  13. Monte Carlo-based treatment planning system calculation engine for microbeam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Rovira, I.; Sempau, J.; Prezado, Y. [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, Barcelona E-08028 (Spain) and ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 rue Jules Horowitz B.P. 220, F-38043 Grenoble Cedex (France); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, Barcelona E-08028 (Spain); Laboratoire Imagerie et modelisation en neurobiologie et cancerologie, UMR8165, Centre National de la Recherche Scientifique (CNRS), Universites Paris 7 et Paris 11, Bat 440., 15 rue Georges Clemenceau, F-91406 Orsay Cedex (France)

    2012-05-15

    Purpose: Microbeam radiation therapy (MRT) is a synchrotron radiotherapy technique that explores the limits of the dose-volume effect. Preclinical studies have shown that MRT irradiations (arrays of 25-75-{mu}m-wide microbeams spaced by 200-400 {mu}m) are able to eradicate highly aggressive animal tumor models while healthy tissue is preserved. These promising results have provided the basis for the forthcoming clinical trials at the ID17 Biomedical Beamline of the European Synchrotron Radiation Facility (ESRF). The first step includes irradiation of pets (cats and dogs) as a milestone before treatment of human patients. Within this context, accurate dose calculations are required. The distinct features of both beam generation and irradiation geometry in MRT with respect to conventional techniques require the development of a specific MRT treatment planning system (TPS). In particular, a Monte Carlo (MC)-based calculation engine for the MRT TPS has been developed in this work. Experimental verification in heterogeneous phantoms and optimization of the computation time have also been performed. Methods: The penelope/penEasy MC code was used to compute dose distributions from a realistic beam source model. Experimental verification was carried out by means of radiochromic films placed within heterogeneous slab-phantoms. Once validation was completed, dose computations in a virtual model of a patient, reconstructed from computed tomography (CT) images, were performed. To this end, decoupling of the CT image voxel grid (a few cubic millimeter volume) to the dose bin grid, which has micrometer dimensions in the transversal direction of the microbeams, was performed. Optimization of the simulation parameters, the use of variance-reduction (VR) techniques, and other methods, such as the parallelization of the simulations, were applied in order to speed up the dose computation. Results: Good agreement between MC simulations and experimental results was achieved, even at

  14. Spot-scanning beam proton therapy vs intensity-modulated radiation therapy for ipsilateral head and neck malignancies: A treatment planning comparison

    Energy Technology Data Exchange (ETDEWEB)

    Kandula, Shravan [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Zhu, Xiaorong [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Garden, Adam S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Gillin, Michael [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Rosenthal, David I.; Ang, Kie-Kian [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Mohan, Radhe [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Amin, Mayankkumar V.; Garcia, John A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Wu, Richard; Sahoo, Narayan [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Frank, Steven J., E-mail: sjfrank@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2013-01-01

    Radiation therapy for head and neck malignancies can have side effects that impede quality of life. Theoretically, proton therapy can reduce treatment-related morbidity by minimizing the dose to critical normal tissues. We evaluated the feasibility of spot-scanning proton therapy for head and neck malignancies and compared dosimetry between those plans and intensity-modulated radiation therapy (IMRT) plans. Plans from 5 patients who had undergone IMRT for primary tumors of the head and neck were used for planning proton therapy. Both sets of plans were prepared using computed tomography (CT) scans with the goals of achieving 100% of the prescribed dose to the clinical target volume (CTV) and 95% to the planning TV (PTV) while maximizing conformity to the PTV. Dose-volume histograms were generated and compared, as were conformity indexes (CIs) to the PTVs and mean doses to the organs at risk (OARs). Both modalities in all cases achieved 100% of the dose to the CTV and 95% to the PTV. Mean PTV CIs were comparable (0.371 IMRT, 0.374 protons, p = 0.953). Mean doses were significantly lower in the proton plans to the contralateral submandibular (638.7 cGy IMRT, 4.3 cGy protons, p = 0.002) and parotid (533.3 cGy IMRT, 48.5 cGy protons, p = 0.003) glands; oral cavity (1760.4 cGy IMRT, 458.9 cGy protons, p = 0.003); spinal cord (2112.4 cGy IMRT, 249.2 cGy protons, p = 0.002); and brainstem (1553.52 cGy IMRT, 166.2 cGy protons, p = 0.005). Proton plans also produced lower maximum doses to the spinal cord (3692.1 cGy IMRT, 2014.8 cGy protons, p = 0.034) and brainstem (3412.1 cGy IMRT, 1387.6 cGy protons, p = 0.005). Normal tissue V{sub 10}, V{sub 30}, and V{sub 50} values were also significantly lower in the proton plans. We conclude that spot-scanning proton therapy can significantly reduce the integral dose to head and neck critical structures. Prospective studies are underway to determine if this reduced dose translates to improved quality of life.

  15. Advanced treatment planning using direct 4D optimisation for pencil-beam scanned particle therapy

    Science.gov (United States)

    Bernatowicz, Kinga; Zhang, Ye; Perrin, Rosalind; Weber, Damien C.; Lomax, Antony J.

    2017-08-01

    We report on development of a new four-dimensional (4D) optimisation approach for scanned proton beams, which incorporates both irregular motion patterns and the delivery dynamics of the treatment machine into the plan optimiser. Furthermore, we assess the effectiveness of this technique to reduce dose to critical structures in proximity to moving targets, while maintaining effective target dose homogeneity and coverage. The proposed approach has been tested using both a simulated phantom and a clinical liver cancer case, and allows for realistic 4D calculations and optimisation using irregular breathing patterns extracted from e.g. 4DCT-MRI (4D computed tomography-magnetic resonance imaging). 4D dose distributions resulting from our 4D optimisation can achieve almost the same quality as static plans, independent of the studied geometry/anatomy or selected motion (regular and irregular). Additionally, current implementation of the 4D optimisation approach requires less than 3 min to find the solution for a single field planned on 4DCT of a liver cancer patient. Although 4D optimisation allows for realistic calculations using irregular breathing patterns, it is very sensitive to variations from the planned motion. Based on a sensitivity analysis, target dose homogeneity comparable to static plans (D5-D95  <5%) has been found only for differences in amplitude of up to 1 mm, for changes in respiratory phase  <200 ms and for changes in the breathing period of  <20 ms in comparison to the motions used during optimisation. As such, methods to robustly deliver 4D optimised plans employing 4D intensity-modulated delivery are discussed.

  16. Oxygen beams for therapy: advanced biological treatment planning and experimental verification

    Science.gov (United States)

    Sokol, O.; Scifoni, E.; Tinganelli, W.; Kraft-Weyrather, W.; Wiedemann, J.; Maier, A.; Boscolo, D.; Friedrich, T.; Brons, S.; Durante, M.; Krämer, M.

    2017-10-01

    Nowadays there is a rising interest towards exploiting new therapeutical beams beyond carbon ions and protons. In particular, 16 O ions are being widely discussed due to their increased LET distribution. In this contribution, we report on the first experimental verification of biologically optimized treatment plans, accounting for different biological effects, generated with the TRiP98 planning system with 16 O beams, performed at HIT and GSI. This implies the measurements of 3D profiles of absorbed dose as well as several biological measurements. The latter includes the measurements of relative biological effectiveness along the range of linear energy transfer values from  ≈20 up to  ≈750 keV μ m-1 , oxygen enhancement ratio values and the verification of the kill-painting approach, to overcome hypoxia, with a phantom imitating an unevenly oxygenated target. With the present implementation, our treatment planning system is able to perform a comparative analysis of different ions, according to any given condition of the target. For the particular cases of low target oxygenation, 16 O ions demonstrate a higher peak-to-entrance dose ratio for the same cell killing in the target region compared to 12 C ions. Based on this phenomenon, we performed a short computational analysis to reveal the potential range of treatment plans, where 16 O can benefit over lighter modalities. It emerges that for more hypoxic target regions (partial oxygen pressure of  ≈0.15% or lower) and relatively low doses (≈4 Gy or lower) the choice of 16 O over 12 C or 4 He may be justified.

  17. Comparison of dose calculation algorithms for treatment planning in external photon beam therapy for clinical situations.

    Science.gov (United States)

    Knöös, Tommy; Wieslander, Elinore; Cozzi, Luca; Brink, Carsten; Fogliata, Antonella; Albers, Dirk; Nyström, Håkan; Lassen, Søren

    2006-11-21

    A study of the performance of five commercial radiotherapy treatment planning systems (TPSs) for common treatment sites regarding their ability to model heterogeneities and scattered photons has been performed. The comparison was based on CT information for prostate, head and neck, breast and lung cancer cases. The TPSs were installed locally at different institutions and commissioned for clinical use based on local procedures. For the evaluation, beam qualities as identical as possible were used: low energy (6 MV) and high energy (15 or 18 MV) x-rays. All relevant anatomical structures were outlined and simple treatment plans were set up. Images, structures and plans were exported, anonymized and distributed to the participating institutions using the DICOM protocol. The plans were then re-calculated locally and exported back for evaluation. The TPSs cover dose calculation techniques from correction-based equivalent path length algorithms to model-based algorithms. These were divided into two groups based on how changes in electron transport are accounted for ((a) not considered and (b) considered). Increasing the complexity from the relatively homogeneous pelvic region to the very inhomogeneous lung region resulted in less accurate dose distributions. Improvements in the calculated dose have been shown when models consider volume scatter and changes in electron transport, especially when the extension of the irradiated volume was limited and when low densities were present in or adjacent to the fields. A Monte Carlo calculated algorithm input data set and a benchmark set for a virtual linear accelerator have been produced which have facilitated the analysis and interpretation of the results. The more sophisticated models in the type b group exhibit changes in both absorbed dose and its distribution which are congruent with the simulations performed by Monte Carlo-based virtual accelerator.

  18. Poster — Thur Eve — 32: Stereotactic Body Radiation Therapy for Peripheral Lung Lesion: Treatment Planning and Quality Assurance

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Shuying; Oliver, Michael; Wang, Xiaofang [Northeast Cancer Centre, Health Sciences North, Sudbury, Ontario (Canada)

    2014-08-15

    Stereotactic body radiation therapy (SBRT), due to its high precision for target localizing, has become widely used to treat tumours at various locations, including the lungs. Lung SBRT program was started at our institution a year ago. Eighteen patients with peripheral lesions up to 3 cm diameter have been treated with 48 Gy in 4 fractions. Based on four-dimensional computed tomography (4DCT) simulation, internal target volume (ITV) was delineated to encompass the respiratory motion of the lesion. A margin of 5 mm was then added to create the planning target volume (PTV) for setup uncertainties. There was no expansion from gross tumour volume (GTV) to clinical target volume (CTV). Pinnacle 9.6 was used as the primary treatment planning system. Volumetric modulated arc therapy (VMAT) technique, with one or two coplanar arcs, generally worked well. For quality assurance (QA), each plan was exported to Eclipse 10 and dose calculation was repeated. Dose volume histograms (DVHs) of the targets and organs at risk (OARs) were then compared between the two treatment planning systems. Winston-Lutz tests were carried out as routine machine QA. Patient-specific QA included ArcCheck measurement with an insert, where an ionization chamber was placed at the centre to measure dose at the isocenter. For the first several patients, and subsequently for the plans with extremely strong modulation, Gafchromic film dosimetry was also employed. For each patient, a mock setup was scheduled prior to treatments. Daily pre- and post-CBCT were acquired for setup and assessment of intra-fractional motion, respectively.

  19. 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

  20. Simultaneous delivery time and aperture shape optimization for the volumetric-modulated arc therapy (VMAT) treatment planning problem.

    Science.gov (United States)

    Mahnam, Mehdi; Gendreau, Michel; Lahrichi, Nadia; Rousseau, Louis-Martin

    2017-06-14

    In this paper, we propose a novel heuristic algorithm for the volumetric-modulated arc therapy treatment planning problem, optimizing the trade-off between delivery time and treatment quality. We present a new mixed integer programming model in which the multi-leaf collimator leaf positions, gantry speed, and dose rate are determined simultaneously. Our heuristic is based on column generation; the aperture configuration is modeled in the columns and the dose distribution and time restriction in the rows. To reduce the number of voxels and increase the efficiency of the master model, we aggregate similar voxels using a clustering technique. The efficiency of the algorithm and the treatment quality are evaluated on a benchmark clinical prostate cancer case. The computational results show that a high-quality treatment is achievable using a four-thread CPU. Finally, we analyze the effects of the various parameters and two leaf-motion strategies.

  1. Simultaneous delivery time and aperture shape optimization for the volumetric-modulated arc therapy (VMAT) treatment planning problem

    Science.gov (United States)

    Mahnam, Mehdi; Gendreau, Michel; Lahrichi, Nadia; Rousseau, Louis-Martin

    2017-07-01

    In this paper, we propose a novel heuristic algorithm for the volumetric-modulated arc therapy treatment planning problem, optimizing the trade-off between delivery time and treatment quality. We present a new mixed integer programming model in which the multi-leaf collimator leaf positions, gantry speed, and dose rate are determined simultaneously. Our heuristic is based on column generation; the aperture configuration is modeled in the columns and the dose distribution and time restriction in the rows. To reduce the number of voxels and increase the efficiency of the master model, we aggregate similar voxels using a clustering technique. The efficiency of the algorithm and the treatment quality are evaluated on a benchmark clinical prostate cancer case. The computational results show that a high-quality treatment is achievable using a four-thread CPU. Finally, we analyze the effects of the various parameters and two leaf-motion strategies.

  2. Impact of tissue specific parameters on the predition of the biological effectiveness for treatment planning in ion beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gruen, Rebecca Antonia

    2014-06-03

    Treatment planning in ion beam therapy requires a reliable estimation of the relative biological effectiveness (RBE) of the irradiated tissue. For the pilot project at GSI Helmholtzzentrum fuer Schwerionenforschung GmbH and at other European ion beam therapy centers RBE prediction is based on a biophysical model, the Local Effect Model (LEM). The model version in use, LEM I, is optimized to give a reliable estimation of RBE in the target volume for carbon ion irradiation. However, systematic deviations are observed for the entrance channel of carbon ions and in general for lighter ions. Thus, the LEM has been continuously developed to improve accuracy. The recent version LEM IV has proven to better describe in-vitro cell experiments. Thus, for the clinical application of LEM IV it is of interest to analyze potential differences compared to LEM I under treatment-like conditions. The systematic analysis presented in this work is aiming at the comparison of RBE-weighted doses resulting from different approaches and model versions for protons and carbon ions. This will facilitate the assessment of consequences for clinical application and the interpretation of clinical results from different institutions. In the course of this thesis it has been shown that the RBE-weighted doses predicted on the basis of LEM IV for typical situations representing chordoma treatments differ on average by less than 10 % to those based on LEM I and thus also allow a consistent interpretation of the clinical results. At Japanese ion beam therapy centers the RBE is estimated using their clinical experience from neutron therapy in combination with in-vitro measurements for carbon ions (HIMAC approach). The methods presented in this work allow direct comparison of the HIMAC approach and the LEM and thus of the clinical results obtained at Japanese and European ion beam therapy centers. Furthermore, the sensitivity of the RBE on the model parameters was evaluated. Among all parameters the

  3. Target splitting in radiation therapy for lung cancer: further developments and exemplary treatment plans

    Directory of Open Access Journals (Sweden)

    Schöller Helmut

    2009-08-01

    Full Text Available Abstract Background Reporting further developments evolved since the first report about this conformal technique. Methods Technical progress focused on optimization of the quality assurance (QA program, especially regarding the required work input; and on optimization of beam arrangements. Results Besides performing the regular QA program, additional time consuming dosimetric measurements and verifications no longer have to be accomplished. 'Class solutions' of treatment plans for six patients with non-resected non-small cell lung cancer in locally advanced stages are presented. Target configurations comprise one central and five peripheral tumor sites with different topographic positions to hilus and mediastinum. The mean dose to the primary tumor is 81,9 Gy (range 79,2–90,0 Gy, to macroscopically involved nodes 61,2 Gy (range 55,8–63,0 Gy, to electively treated nodes 45,0 Gy. Treatments are performed twice daily, with fractional doses of 1,8 Gy at an interval of 11 hours. Median overall treatment time is 33 days. The set-up time at the linac does not exceed the average time for any other patient. Conclusion Target splitting is a highly conformal and nonetheless non-expensive method with regard to linac and staff time. It enables secure accelerated high-dose treatments of patients with NSCLC.

  4. A new approach to integrate GPU-based Monte Carlo simulation into inverse treatment plan optimization for proton therapy.

    Science.gov (United States)

    Li, Yongbao; Tian, Zhen; Song, Ting; Wu, Zhaoxia; Liu, Yaqiang; Jiang, Steve; Jia, Xun

    2017-01-07

    Monte Carlo (MC)-based spot dose calculation is highly desired for inverse treatment planning in proton therapy because of its accuracy. Recent studies on biological optimization have also indicated the use of MC methods to compute relevant quantities of interest, e.g. linear energy transfer. Although GPU-based MC engines have been developed to address inverse optimization problems, their efficiency still needs to be improved. Also, the use of a large number of GPUs in MC calculation is not favorable for clinical applications. The previously proposed adaptive particle sampling (APS) method can improve the efficiency of MC-based inverse optimization by using the computationally expensive MC simulation more effectively. This method is more efficient than the conventional approach that performs spot dose calculation and optimization in two sequential steps. In this paper, we propose a computational library to perform MC-based spot dose calculation on GPU with the APS scheme. The implemented APS method performs a non-uniform sampling of the particles from pencil beam spots during the optimization process, favoring those from the high intensity spots. The library also conducts two computationally intensive matrix-vector operations frequently used when solving an optimization problem. This library design allows a streamlined integration of the MC-based spot dose calculation into an existing proton therapy inverse planning process. We tested the developed library in a typical inverse optimization system with four patient cases. The library achieved the targeted functions by supporting inverse planning in various proton therapy schemes, e.g. single field uniform dose, 3D intensity modulated proton therapy, and distal edge tracking. The efficiency was 41.6  ±  15.3% higher than the use of a GPU-based MC package in a conventional calculation scheme. The total computation time ranged between 2 and 50 min on a single GPU card depending on the problem size.

  5. Feasibility assessment of the interactive use of a Monte Carlo algorithm in treatment planning for intraoperative electron radiation therapy

    Science.gov (United States)

    Guerra, Pedro; Udías, José M.; Herranz, Elena; Santos-Miranda, Juan Antonio; Herraiz, Joaquín L.; Valdivieso, Manlio F.; Rodríguez, Raúl; Calama, Juan A.; Pascau, Javier; Calvo, Felipe A.; Illana, Carlos; Ledesma-Carbayo, María J.; Santos, Andrés

    2014-12-01

    This work analysed the feasibility of using a fast, customized Monte Carlo (MC) method to perform accurate computation of dose distributions during pre- and intraplanning of intraoperative electron radiation therapy (IOERT) procedures. The MC method that was implemented, which has been integrated into a specific innovative simulation and planning tool, is able to simulate the fate of thousands of particles per second, and it was the aim of this work to determine the level of interactivity that could be achieved. The planning workflow enabled calibration of the imaging and treatment equipment, as well as manipulation of the surgical frame and insertion of the protection shields around the organs at risk and other beam modifiers. In this way, the multidisciplinary team involved in IOERT has all the tools necessary to perform complex MC dosage simulations adapted to their equipment in an efficient and transparent way. To assess the accuracy and reliability of this MC technique, dose distributions for a monoenergetic source were compared with those obtained using a general-purpose software package used widely in medical physics applications. Once accuracy of the underlying simulator was confirmed, a clinical accelerator was modelled and experimental measurements in water were conducted. A comparison was made with the output from the simulator to identify the conditions under which accurate dose estimations could be obtained in less than 3 min, which is the threshold imposed to allow for interactive use of the tool in treatment planning. Finally, a clinically relevant scenario, namely early-stage breast cancer treatment, was simulated with pre- and intraoperative volumes to verify that it was feasible to use the MC tool intraoperatively and to adjust dose delivery based on the simulation output, without compromising accuracy. The workflow provided a satisfactory model of the treatment head and the imaging system, enabling proper configuration of the treatment planning

  6. Zero echo time MRI-only treatment planning for radiation therapy of brain tumors after resection.

    Science.gov (United States)

    Boydev, C; Demol, B; Pasquier, D; Saint-Jalmes, H; Delpon, G; Reynaert, N

    2017-10-01

    Using magnetic resonance imaging (MRI) as the sole imaging modality for patient modeling in radiation therapy (RT) is a challenging task due to the need to derive electron density information from MRI and construct a so-called pseudo-computed tomography (pCT) image. We have previously published a new method to derive pCT images from head T1-weighted (T1-w) MR images using a single-atlas propagation scheme followed by a post hoc correction of the mapped CT numbers using local intensity information. The purpose of this study was to investigate the performance of our method with head zero echo time (ZTE) MR images. To evaluate results, the mean absolute error in bins of 20 HU was calculated with respect to the true planning CT scan of the patient. We demonstrated that applying our method using ZTE MR images instead of T1-w improved the correctness of the pCT in case of bone resection surgery prior to RT (that is, an example of large anatomical difference between the atlas and the patient). Copyright © 2017. Published by Elsevier Ltd.

  7. Revision of Calibration Method of CT-Number to Stopping-Power-Ratio Conversion for Treatment Planning of Particle Therapy.

    Science.gov (United States)

    Kanematsu, Nobuyuki; Mori, Shinichiro; Inaniwa, Taku

    A calibration method for CT-number to stopping-power-ratio conversion was recently proposed as a revision of the Japanese de facto standard method that has been used at particle therapy centers in Japan for over a decade. The revised method deals with 11 representative tissues of specific elemental composition and density, based on a latest compilation of standard tissue data. We report here how the revision was actually implemented into clinical practice. We applied the revised method to 7 CT-scanning conditions currently in use for treatment planning. For each condition, we derived CT numbers and stopping-power ratios of the representative tissues to constitute a polyline conversion function. We analyzed the change of target water-equivalent depth by the revision for 38 beams in treatment plans for 13 randomly sampled patients. The revision caused a mean change of +0.3 mm with a standard deviation of 0.4 mm. The maximum change was +1.2 mm or +0.5% of the depth, which may be clinically insignificant. The transition to the revised method was straightforward and would slightly improve the accuracy of the beam range in particle therapy.

  8. A treatment planning study of the potential of geometrical tracking for intensity modulated proton therapy of lung cancer

    DEFF Research Database (Denmark)

    Munck af Rosenschöld, Per; Aznar, Marianne; Nygaard, Ditte Eklund

    2010-01-01

    Proton therapy of lung cancer holds the potential for a reduction of the volume of irradiated normal lung tissue. In this work we investigate the robustness of intensity modulated proton therapy (IMPT) plans to motion, and evaluate a geometrical tumour tracking method to compensate for tumour...

  9. A treatment planning study of the potential of geometrical tracking for intensity modulated proton therapy of lung cancer

    DEFF Research Database (Denmark)

    af Rosenschöld, Per Munck; Aznar, Marianne C; Nygaard, Ditte E

    2010-01-01

    Proton therapy of lung cancer holds the potential for a reduction of the volume of irradiated normal lung tissue. In this work we investigate the robustness of intensity modulated proton therapy (IMPT) plans to motion, and evaluate a geometrical tumour tracking method to compensate for tumour mot...

  10. A case study of radiotherapy planning for Intensity Modulation Radiation Therapy for the whole scalp with matching electron treatment

    Energy Technology Data Exchange (ETDEWEB)

    Sponseller, Patricia, E-mail: sponselp@uw.edu [Masters Program at the University of Wisconsin at La Crosse, La Crosse, WI (United States); Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA (United States); Paravathaneni, Upendra [Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA (United States)

    2013-07-01

    The purpose of this report is to communicate a technique to match an electron field to the dose distribution of an Intensity-Modulated Radiation Therapy (IMRT) plan. A patient with multiple areas of squamous cell carcinoma over the scalp was treated using 60 Gy in 2.0-Gy fractions to the entire scalp and first echelon nodes with multiple 6-MV photon fields. To deliver an adequate dose to the scalp, a custom 1.0-cm bolus helmet was fashioned using a solid piece of aquaplast. Along with the IMRT scalp treatment, a left zygoma area was treated with electrons matching the anterior border of the IMRT dose distribution. The border was matched by creating a left lateral field with the multileaf collimator shaped to the IMRT dose distribution. The result indicated an adequate dose to the skin match between the IMRT plan and the electron field. Results were confirmed using optically stimulated luminescence placed at the skin match area, so that the dose matched the prescription within 10%.

  11. Reducing Patient Waiting Times for Radiation Therapy and Improving the Treatment Planning Process: a Discrete-event Simulation Model (Radiation Treatment Planning).

    Science.gov (United States)

    Babashov, V; Aivas, I; Begen, M A; Cao, J Q; Rodrigues, G; D'Souza, D; Lock, M; Zaric, G S

    2017-06-01

    We analysed the radiotherapy planning process at the London Regional Cancer Program to determine the bottlenecks and to quantify the effect of specific resource levels with the goal of reducing waiting times. We developed a discrete-event simulation model of a patient's journey from the point of referral to a radiation oncologist to the start of radiotherapy, considering the sequential steps and resources of the treatment planning process. We measured the effect of several resource changes on the ready-to-treat to treatment (RTTT) waiting time and on the percentage treated within a 14 calendar day target. Increasing the number of dosimetrists by one reduced the mean RTTT by 6.55%, leading to 84.92% of patients being treated within the 14 calendar day target. Adding one more oncologist decreased the mean RTTT from 10.83 to 10.55 days, whereas a 15% increase in arriving patients increased the waiting time by 22.53%. The model was relatively robust to the changes in quantity of other resources. Our model identified sensitive and non-sensitive system parameters. A similar approach could be applied by other cancer programmes, using their respective data and individualised adjustments, which may be beneficial in making the most effective use of limited resources. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  12. Impact of Multileaf Collimator Configuration Parameters on the Dosimetric Accuracy of 6-MV Intensity-Modulated Radiation Therapy Treatment Plans.

    Science.gov (United States)

    Petersen, Nick; Perrin, David; Newhauser, Wayne; Zhang, Rui

    2017-01-01

    The purpose of this study was to evaluate the impact of selected configuration parameters that govern multileaf collimator (MLC) transmission and rounded leaf offset in a commercial treatment planning system (TPS) (Pinnacle3, Philips Medical Systems, Andover, MA, USA) on the accuracy of intensity-modulated radiation therapy (IMRT) dose calculation. The MLC leaf transmission factor was modified based on measurements made with ionization chambers. The table of parameters containing rounded-leaf-end offset values was modified by measuring the radiation field edge as a function of leaf bank position with an ionization chamber in a scanning water-tank dosimetry system and comparing the locations to those predicted by the TPS. The modified parameter values were validated by performing IMRT quality assurance (QA) measurements on 19 gantry-static IMRT plans. Planar dose measurements were performed with radiographic film and a diode array (MapCHECK2) and compared to TPS calculated dose distributions using default and modified configuration parameters. Based on measurements, the leaf transmission factor was changed from a default value of 0.001 to 0.005. Surprisingly, this modification resulted in a small but statistically significant worsening of IMRT QA gamma-index passing rate, which revealed that the overall dosimetric accuracy of the TPS depends on multiple configuration parameters in a manner that is coupled and not intuitive because of the commissioning protocol used in our clinic. The rounded leaf offset table had little room for improvement, with the average difference between the default and modified offset values being -0.2 ± 0.7 mm. While our results depend on the current clinical protocols, treatment unit and TPS used, the methodology used in this study is generally applicable. Different clinics could potentially obtain different results and improve their dosimetric accuracy using our approach.

  13. Impact of multileaf collimator configuration parameters on the dosimetric accuracy of 6-MV Intensity-Modulated radiation therapy treatment plans

    Directory of Open Access Journals (Sweden)

    Nick Petersen

    2017-01-01

    Full Text Available The purpose of this study was to evaluate the impact of selected configuration parameters that govern multileaf collimator (MLC transmission and rounded leaf offset in a commercial treatment planning system (TPS (Pinnacle3, Philips Medical Systems, Andover, MA, USA on the accuracy of intensity-modulated radiation therapy (IMRT dose calculation. The MLC leaf transmission factor was modified based on measurements made with ionization chambers. The table of parameters containing rounded-leaf-end offset values was modified by measuring the radiation field edge as a function of leaf bank position with an ionization chamber in a scanning water-tank dosimetry system and comparing the locations to those predicted by the TPS. The modified parameter values were validated by performing IMRT quality assurance (QA measurements on 19 gantry-static IMRT plans. Planar dose measurements were performed with radiographic film and a diode array (MapCHECK2 and compared to TPS calculated dose distributions using default and modified configuration parameters. Based on measurements, the leaf transmission factor was changed from a default value of 0.001 to 0.005. Surprisingly, this modification resulted in a small but statistically significant worsening of IMRT QA gamma-index passing rate, which revealed that the overall dosimetric accuracy of the TPS depends on multiple configuration parameters in a manner that is coupled and not intuitive because of the commissioning protocol used in our clinic. The rounded leaf offset table had little room for improvement, with the average difference between the default and modified offset values being −0.2 ± 0.7 mm. While our results depend on the current clinical protocols, treatment unit and TPS used, the methodology used in this study is generally applicable. Different clinics could potentially obtain different results and improve their dosimetric accuracy using our approach.

  14. Application of adjoint Monte Carlo to accelerate simulations of mono-directional beams in treatment planning for Boron Neutron Capture Therapy

    NARCIS (Netherlands)

    Nievaart, V.A.; Legrady, D.; Moss, R.L.; Kloosterman, J.L.; Van der Hagen, T.H.; Van Dam, H.

    2007-01-01

    This paper deals with the application of the adjoint transport theory in order to optimize Monte Carlo based radiotherapy treatment planning. The technique is applied to Boron Neutron Capture Therapy where most often mixed beams of neutrons and gammas are involved. In normal forward Monte Carlo

  15. Whole-body hybrid imaging concept for the integration of PET/MR into radiation therapy treatment planning

    Science.gov (United States)

    Paulus, Daniel H.; Oehmigen, Mark; Grueneisen, Johannes; Umutlu, Lale; Quick, Harald H.

    2016-05-01

    Modern radiation therapy (RT) treatment planning is based on multimodality imaging. With the recent availability of whole-body PET/MR hybrid imaging new opportunities arise to improve target volume delineation in RT treatment planning. This, however, requires dedicated RT equipment for reproducible patient positioning on the PET/MR system, which has to be compatible with MR and PET imaging. A prototype flat RT table overlay, radiofrequency (RF) coil holders for head imaging, and RF body bridges for body imaging were developed and tested towards PET/MR system integration. Attenuation correction (AC) of all individual RT components was performed by generating 3D CT-based template models. A custom-built program for μ-map generation assembles all AC templates depending on the presence and position of each RT component. All RT devices were evaluated in phantom experiments with regards to MR and PET imaging compatibility, attenuation correction, PET quantification, and position accuracy. The entire RT setup was then evaluated in a first PET/MR patient study on five patients at different body regions. All tested devices are PET/MR compatible and do not produce visible artifacts or disturb image quality. The RT components showed a repositioning accuracy of better than 2 mm. Photon attenuation of  -11.8% in the top part of the phantom was observable, which was reduced to  -1.7% with AC using the μ-map generator. Active lesions of 3 subjects were evaluated in terms of SUVmean and an underestimation of  -10.0% and  -2.4% was calculated without and with AC of the RF body bridges, respectively. The new dedicated RT equipment for hybrid PET/MR imaging enables acquisitions in all body regions. It is compatible with PET/MR imaging and all hardware components can be corrected in hardware AC by using the suggested μ-map generator. These developments provide the technical and methodological basis for integration of PET/MR hybrid imaging into RT planning.

  16. Does electron and proton therapy reduce the risk of radiation induced cancer after spinal irradiation for childhood medulloblastoma? A comparative treatment planning study

    Energy Technology Data Exchange (ETDEWEB)

    Xiangkui Mu; Zackrisson, Bjoern [Umeaa Univ. (Sweden). Dept. of Radiation Sciences; Bjoerk-Eriksson, Thomas; Johansson, Lennart; Karlsson, Mikael [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Oncology; Nill, Simeon; Oelfke, Uwe [DKFZ-Heidelberg, (Germany). Dept. of Medical Physics; Johansson, Karl-Axel [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Therapeutic Radiation Physics; Gagliardi, Giovanna [Radiumhemmet, Stockholm (Sweden). Dept. of Hospital Physics

    2005-09-01

    The aim of this treatment planning comparison study was to explore different spinal irradiation techniques with respect to the risk of late side-effects, particularly radiation-induced cancer. The radiotherapy techniques compared were conventional photon therapy, intensity modulated x-ray therapy (IMXT), conventional electron therapy, intensity/energy modulated electron therapy (IMET) and proton therapy (IMPT). CT images for radiotherapy use from five children, median age 8 and diagnosed with medulloblastoma, were selected for this study. Target volumes and organs at risk were defined in 3-D. Treatment plans using conventional photon therapy, IMXT, conventional electron therapy, IMET and IMPT were set up. The probability of normal tissue complication (NTCP) and the risk of cancer induction were calculated using models with parameters-sets taken from published data for the general population; dose data were taken from dose volume histograms (DVH). Similar dose distributions in the targets were achieved with all techniques but the absorbed doses in the organs-at-risk varied significantly between the different techniques. The NTCP models based on available data predicted very low probabilities for side-effects in all cases. However, the effective mean doses outside the target volumes, and thus the predicted risk of cancer induction, varied significantly between the techniques. The highest lifetime risk of secondary cancers was estimated for IMXT (30%). The lowest risk was found with IMPT (4%). The risks associated with conventional photon therapy, electron therapy and IMET were 20%, 21% and 15%, respectively. This model study shows that spinal irradiation of young children with photon and electron techniques results in a substantial risk of radiation-induced secondary cancers. Multiple beam IMXT seems to be associated with a particularly high risk of secondary cancer induction. To minimise this risk, IMPT should be the treatment of choice. If proton therapy is not

  17. Automatic treatment planning facilitates fast generation of high-quality treatment plans for esophageal cancer

    DEFF Research Database (Denmark)

    Hansen, Christian Rønn; Nielsen, Morten; Bertelsen, Anders Smedegaard

    2017-01-01

    cancer patients. MATERIAL AND METHODS: Thirty-two consecutive inoperable patients with esophageal cancer originally treated with manually (MA) generated volumetric modulated arc therapy (VMAT) plans were retrospectively replanned using an auto-planning engine. All plans were optimized with one full 6MV...... to the lungs. The automation of the planning process generated esophageal cancer treatment plans quickly and with high quality....

  18. Treatment plan evaluation for interstitial photodynamic therapy in a mouse model by Monte Carlo simulation with FullMonte

    Directory of Open Access Journals (Sweden)

    Jeffrey eCassidy

    2015-02-01

    Full Text Available Monte Carlo (MC simulation is recognized as the gold standard for biophotonic simulation, capturing all relevant physics and material properties at the perceived cost of high computing demands. Tetrahedral-mesh-based MC simulations particularly are attractive due to the ability to refine the mesh at will to conform to complicated geometries or user-defined resolution requirements. Since no approximations of material or light-source properties are required, MC methods are applicable to the broadest set of biophotonic simulation problems. MC methods also have other implementation features including inherent parallelism, and permit a continuously-variable quality-runtime tradeoff. We demonstrate here a complete MC-based prospective fluence dose evaluation system for interstitial PDT to generate dose-volume histograms on a tetrahedral mesh geometry description. To our knowledge, this is the first such system for general interstitial photodynamic therapy employing MC methods and is therefore applicable to a very broad cross-section of anatomy and material properties. We demonstrate that evaluation of dose-volume histograms is an effective variance-reduction scheme in its own right which greatly reduces the number of packets required and hence runtime required to achieve acceptable result confidence. We conclude that MC methods are feasible for general PDT treatment evaluation and planning, and considerably less costly than widely believed.

  19. The role of Cobalt-60 source in Intensity Modulated Radiation Therapy: From modeling finite sources to treatment planning and conformal dose delivery

    Science.gov (United States)

    Dhanesar, Sandeep Kaur

    Cobalt-60 (Co-60) units played an integral role in radiation therapy from the mid-1950s to the 1970s. Although they continue to be used to treat cancer in some parts of the world, their role has been significantly reduced due to the invention of medical linear accelerators. A number of groups have indicated a strong potential for Co-60 units in modern radiation therapy. The Medical Physics group at the Cancer Center of the Southeastern Ontario and Queen's University has shown the feasibility of Intensity Modulated Radiation Therapy (IMRT) via simple conformal treatment planning and dose delivery using a Co-60 unit. In this thesis, initial Co-60 tomotherapy planning investigations on simple uniform phantoms are extended to actual clinical cases based on patient CT data. The planning is based on radiation dose data from a clinical Co-60 unit fitted with a multileaf collimator (MLC) and modeled in the EGSnrc Monte Carlo system. An in house treatment planning program is used to calculate IMRT dose distributions. Conformal delivery in a single slice on a uniform phantom based on sequentially delivered pencil beams is verified by Gafchromic film. Volumetric dose distributions for Co-60 serial tomotherapy are then generated for typical clinical sites that had been treated at our clinic by conventional 6MV IMRT using Varian Eclipse treatment plans. The Co-60 treatment plans are compared with the clinical IMRT plans using conventional matrices such as dose volume histograms (DVH). Dose delivery based on simultaneously opened MLC leaves is also explored and a novel MLC segmentation method is proposed. In order to increase efficiency of dose calculations, a novel convolution based fluence model for treatment planning is also proposed. The ion chamber measurements showed that the Monte Carlo modeling of the beam data under the MIMiC MLC is accurate. The film measurements from the uniform phantom irradiations confirm that IMRT plans from our in-house treatment planning system

  20. 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

  1. Treatment plan comparison of Linac step and shoot,Tomotherapy, RapidArc, and Proton therapy for prostate cancer using dosimetrical and biological index

    CERN Document Server

    Lee, Suk; Chang, Kyung Hwan; Shim, Jang Bo; Kim, Kwang Hyeon; Lee, Nam Kwon; Park, Young Je; Kim, Chul Yong; Cho, Sam Ju; Lee, Sang Hoon; Min, Chul Kee; Kim, Woo Chul; Cho, Kwang Hwan; Huh, Hyun Do; Lim, Sangwook; Shin, Dongho

    2015-01-01

    The purpose of this study was to use various dosimetrical indices to determine the best IMRT modality technique for treating patients with prostate cancer. Ten patients with prostate cancer were included in this study. Intensity modulated radiation therapy plans were designed to include different modalities, including the linac step and shoot, Tomotherapy, RapidArc, and Proton systems. Various dosimetrical indices, like the prescription isodose to target volume (PITV) ratio, conformity index (CI), homogeneity index (HI), target coverage index (TCI), modified dose homogeneity index (MHI), conformation number (CN), critical organ scoring index (COSI), and quality factor (QF) were determined to compare the different treatment plans. Biological indices such as the generalized equivalent uniform dose (gEUD), based tumor control probability (TCP), and normal tissue complication probability (NTCP) were also calculated and used to compare the treatment plans. The RapidArc plan attained better PTV coverage, as evidenc...

  2. Medical nutrition therapy planning

    OpenAIRE

    Torović Ljilja; Grujičić Maja; Pavlović-Trajković Ljiljana; Jovičić Jelena; Novaković Budimka; Balać Dragana

    2010-01-01

    Introduction. Diet has vital, preventive and therapeutic functions. Medical nutrition therapy is a part of the Standardized Nutrition Care Process integrated in health care systems. Material and methods. An overview of the Nutrition Care Process model and the application of nutrition guidelines based on literature, reports, documents and programmes of international health, food and physical activity authorities was done. Results. The Nutrition Care Process model requires registered diet...

  3. PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy

    DEFF Research Database (Denmark)

    Kornerup, Josefine S.; Brodin, N. P.; Bjork-Eriksson, T.

    2015-01-01

    OBJECTIVE: To investigate the impact of including fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). METHODS: Target volumes were first delineated without and subsequently re-delineated with access to (18)F-FDG PET...... scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (3DCRT) and intensity-modulated proton therapy (IMPT). The results were evaluated by comparison of target volumes, target dose coverage parameters, normal tissue complication probability (NTCP...... volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT. CONCLUSION: Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing...

  4. Mapping of RBE-Weighted Doses Between HIMAC- and LEM-Based Treatment Planning Systems for Carbon Ion Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Steinstraeter, Olaf, E-mail: o.steinstraeter@gsi.de [Abteilung Biophysik, GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Gruen, Rebecca [Abteilung Biophysik, GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Institut fuer Medizinische Physik und Strahlenschutz, TH-Mittelhessen, Giessen (Germany); Fachbereich Medizin, Philipps-Universitaet Marburg, Marburg (Germany); Scholz, Uwe [Abteilung Biophysik, GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Institut fuer Festkoerperphysik, Technische Universitaet Darmstadt, Darmstadt (Germany); Friedrich, Thomas [Abteilung Biophysik, GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Durante, Marco [Abteilung Biophysik, GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Institut fuer Festkoerperphysik, Technische Universitaet Darmstadt, Darmstadt (Germany); Scholz, Michael [Abteilung Biophysik, GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

    2012-11-01

    Purpose: A method was developed to convert clinically prescribed RBE (Relative Biological Effectiveness)-weighted doses from the approach used at the Heavy-Ion Medical Accelerator (HIMAC) at the National Institute of Radiological Science, Chiba, Japan, to the LEM (Local Effect Model)-based TReatment planning for Particles (TRiP98) approach used in the pilot project at the GSI Helmholtzzentrum, Darmstadt, and the Heidelberg Ion-Beam Therapy Center (HIT). Methods and Materials: The proposed conversion method is based on a simulation of the fixed spread-out Bragg peak (SOBP) depth dose profiles as used for the irradiation at HIMAC by LEM/TRiP98 and a recalculation of the resulting RBE-weighted dose distribution. We present data according to the clinical studies conducted at GSI in the past decade (LEM I), as well as data used in current studies (refined LEM version: LEM IV). Results: We found conversion factors (RBE-weighted dose LEM/RBE-weighted dose HIMAC) reaching from 0.4 to 2.0 for prescribed carbon ion doses from 1 to 60 Gy (RBE) for SOBP extensions ranging from 20 to 120 mm according to the HIMAC approach. A conversion factor of 1.0 was found for approximately 5 Gy (RBE). The conversion factor decreases with increasing prescribed dose. Slightly smaller values for the LEM IV-based data set compared with LEM I were found. A significant dependence of the conversion factor from the SOBP width could be observed in particular for LEM IV, whereas the depth dependence was found to be small. Conclusions: For the interpretation and comparison of clinical trials performed at HIMAC and GSI/HIT, it is of extreme importance to consider these conversion factors because according to the various methods to determine the RBE-weighted dose, similar dose values might not necessarily be related to similar clinical outcomes.

  5. 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.

  6. Precision IORT - Image guided intraoperative radiation therapy (igIORT) using online treatment planning including tissue heterogeneity correction.

    Science.gov (United States)

    Schneider, Frank; Bludau, Frederic; Clausen, Sven; Fleckenstein, Jens; Obertacke, Udo; Wenz, Frederik

    2017-05-01

    To the present date, IORT has been eye and hand guided without treatment planning and tissue heterogeneity correction. This limits the precision of the application and the precise documentation of the location and the deposited dose in the tissue. Here we present a set-up where we use image guidance by intraoperative cone beam computed tomography (CBCT) for precise online Monte Carlo treatment planning including tissue heterogeneity correction. An IORT was performed during balloon kyphoplasty using a dedicated Needle Applicator. An intraoperative CBCT was registered with a pre-op CT. Treatment planning was performed in Radiance using a hybrid Monte Carlo algorithm simulating dose in homogeneous (MCwater) and heterogeneous medium (MChet). Dose distributions on CBCT and pre-op CT were compared with each other. Spinal cord and the metastasis doses were evaluated. The MCwater calculations showed a spherical dose distribution as expected. The minimum target dose for the MChet simulations on pre-op CT was increased by 40% while the maximum spinal cord dose was decreased by 35%. Due to the artefacts on the CBCT the comparison between MChet simulations on CBCT and pre-op CT showed differences up to 50% in dose. igIORT and online treatment planning improves the accuracy of IORT. However, the current set-up is limited by CT artefacts. Fusing an intraoperative CBCT with a pre-op CT allows the combination of an accurate dose calculation with the knowledge of the correct source/applicator position. This method can be also used for pre-operative treatment planning followed by image guided surgery. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  7. A treatment planning study of the potential of geometrical tracking for intensity modulated proton therapy of lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Munck af Rosenschoeld, Per; Aznar, Marianne C.; Nygaard, Ditte E.; Persson, Gitte F.; Korreman, Stine S.; Engelholm, Svend Aage (Dept. of Radiation Oncology, Copenhagen Univ. Hospital (Rigshospitalet), Copenhagen (Denmark)), E-mail: per.munck@rh.regionh.dk; Nystroem, Haakan (Niels Bohr Inst., Copenhagen Univ., Copenhagen (Denmark))

    2010-10-15

    Background. Proton therapy of lung cancer holds the potential for a reduction of the volume of irradiated normal lung tissue. In this work we investigate the robustness of intensity modulated proton therapy (IMPT) plans to motion, and evaluate a geometrical tumour tracking method to compensate for tumour motion. Material and methods. Seven patients with a nine targets with 4DCT scans were selected. IMPT plans were made on the midventilation phase using a 3-field technique. The plans were transferred and calculated on the remaining nine phases of the 4DCT, and the combined dose distribution was summed using deformable image registration (DIR). An additional set of plans were made in which the proton beam was simply geometrically shifted to the centre of the gross tumour volume (GTV), i.e. simulating tracking of the tumour motion but without on-line adjustment of the proton energies. A possible interplay effect between the dynamics of the spot scanning delivery and the tumour motion has not been considered in this work. Results. Around 97-100% of the GTV was covered by 95% of the prescribed dose (V95) for a tumour displacement of less than about 1 cm with a static beam. For the remaining three of nine targets with a larger motion the tracking method studied provided a marked improvement over static beam; raising the GTV V95 from 95 to 100%, 82 to 98% and 51 to 97%, respectively. Conclusion. The possibility of performing DIR and summing the dose on the 4DCT data set was shown to be feasible. The fairly simplistic tracking method suggested here resulted in a marked improvement in GTV coverage for tumours with large intra-fractional motion (>1 cm displacement), indicating that on-line adjustment of the proton energies may be redundant.

  8. Clinical Evaluation of Normalized Metal Artifact Reduction in kVCT Using MVCT Prior Images (MVCT-NMAR) for Radiation Therapy Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Paudel, Moti Raj, E-mail: mpaudel@ualberta.ca [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Mackenzie, Marc [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Fallone, B. Gino [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Department of Physics, University of Alberta, Edmonton, AB (Canada); Department of Medical Physics, Cross Cancer Institute, Edmonton, AB (Canada); Rathee, Satyapal [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Department of Medical Physics, Cross Cancer Institute, Edmonton, AB (Canada)

    2014-07-01

    Purpose: To evaluate the metal artifacts in diagnostic kilovoltage computed tomography (kVCT) images of patients that are corrected by use of a normalized metal artifact reduction (NMAR) method with megavoltage CT (MVCT) prior images: MVCT-NMAR. Methods and Materials: MVCT-NMAR was applied to images from 5 patients: 3 with dual hip prostheses, 1 with a single hip prosthesis, and 1 with dental fillings. The corrected images were evaluated for visualization of tissue structures and their interfaces and for radiation therapy dose calculations. They were compared against the corresponding images corrected by the commercial orthopedic metal artifact reduction algorithm in a Phillips CT scanner. Results: The use of MVCT images for correcting kVCT images in the MVCT-NMAR technique greatly reduces metal artifacts, avoids secondary artifacts, and makes patient images more useful for correct dose calculation in radiation therapy. These improvements are significant, provided the MVCT and kVCT images are correctly registered. The remaining and the secondary artifacts (soft tissue blurring, eroded bones, false bones or air pockets, CT number cupping within the metal) present in orthopedic metal artifact reduction corrected images are removed in the MVCT-NMAR corrected images. A large dose reduction was possible outside the planning target volume (eg, 59.2 Gy to 52.5 Gy in pubic bone) when these MVCT-NMAR corrected images were used in TomoTherapy treatment plans without directional blocks for a prostate cancer patient. Conclusions: The use of MVCT-NMAR corrected images in radiation therapy treatment planning could improve the treatment plan quality for patients with metallic implants.

  9. Dosimetric verification and clinical evaluation of a new commercially available Monte Carlo-based dose algorithm for application in stereotactic body radiation therapy (SBRT) treatment planning

    Science.gov (United States)

    Fragoso, Margarida; Wen, Ning; Kumar, Sanath; Liu, Dezhi; Ryu, Samuel; Movsas, Benjamin; Munther, Ajlouni; Chetty, Indrin J.

    2010-08-01

    Modern cancer treatment techniques, such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT), have greatly increased the demand for more accurate treatment planning (structure definition, dose calculation, etc) and dose delivery. The ability to use fast and accurate Monte Carlo (MC)-based dose calculations within a commercial treatment planning system (TPS) in the clinical setting is now becoming more of a reality. This study describes the dosimetric verification and initial clinical evaluation of a new commercial MC-based photon beam dose calculation algorithm, within the iPlan v.4.1 TPS (BrainLAB AG, Feldkirchen, Germany). Experimental verification of the MC photon beam model was performed with film and ionization chambers in water phantoms and in heterogeneous solid-water slabs containing bone and lung-equivalent materials for a 6 MV photon beam from a Novalis (BrainLAB) linear accelerator (linac) with a micro-multileaf collimator (m3 MLC). The agreement between calculated and measured dose distributions in the water phantom verification tests was, on average, within 2%/1 mm (high dose/high gradient) and was within ±4%/2 mm in the heterogeneous slab geometries. Example treatment plans in the lung show significant differences between the MC and one-dimensional pencil beam (PB) algorithms within iPlan, especially for small lesions in the lung, where electronic disequilibrium effects are emphasized. Other user-specific features in the iPlan system, such as options to select dose to water or dose to medium, and the mean variance level, have been investigated. Timing results for typical lung treatment plans show the total computation time (including that for processing and I/O) to be less than 10 min for 1-2% mean variance (running on a single PC with 8 Intel Xeon X5355 CPUs, 2.66 GHz). Overall, the iPlan MC algorithm is demonstrated to be an accurate and efficient dose algorithm, incorporating robust tools for MC

  10. DISCHARGE PLANNING INCREASE THERAPY OBEDIENT OF PATIENTS

    Directory of Open Access Journals (Sweden)

    Nursalam Nursalam

    2017-07-01

    Full Text Available Introduction: Discharge planning is a nurses learning  process of patients  hospitalized in  the hospital. Discharge planning  includes all treatments given to the patients  from the time of admission, during hospitalization, until the time of discharge. The aimed of this study was to evaluate  the patient’s  compliance for therapy (oral and injection medicine, nutrition and activities. Method: A quasy experimental purposive sampling design was used in this study. There were 14 respondents with DHF and GE who met to the inclusion criteria. The independent variable was Discharge planning and the dependent variable was patient’s  compliance for therapy.  Data were collected by using questionaire of medicine, nutrition and activity then analyzed by using Wilcoxon Signed Rank Test and Mann Whitney U Test with significance level α≤0.05. Result: The result showed that discharge planning had significance influence to patient’s  compliance for therapy (p= 0.028. Discussion: It can be concluded that discharge planning has an effect to increase patient’s  compliance for therapy (oral and injection medicine, nutrition and activities.

  11. Preliminary evaluation of multifield and single-field optimization for the treatment planning of spot-scanning proton therapy of head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Enzhuo M.; Liu, Wei; Wu, Richard; Zhang, Xiaodong; Zhu, X. Ronald; Mohan, Radhe [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Li, Yupeng [Varian Medical Systems, Inc., Palo Alto, California 94304 (United States); Frank, Steven J. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2013-08-15

    Purpose: Spot-scanning proton therapy (SSPT) using multifield optimization (MFO) can generate highly conformal dose distributions, but it is more sensitive to setup and range uncertainties than SSPT using single-field optimization (SFO). The authors compared the two optimization methods for the treatment of head and neck cancer with bilateral targets and determined the superior method on the basis of both the plan quality and the plan robustness in the face of setup and range uncertainties.Methods: Four patients with head and neck cancer with bilateral targets who received SSPT treatment in the authors' institution were studied. The patients had each been treated with a MFO plan using three fields. A three-field SFO plan (3F-SFO) and a two-field SFO plan (2F-SFO) with the use of a range shifter in the beam line were retrospectively generated for each patient. The authors compared the plan quality and robustness to uncertainties of the SFO plans with the MFO plans. Robustness analysis of each plan was performed to generate the two dose distributions consisting of the highest and the lowest possible doses (worst-case doses) from the spatial and range perturbations at every voxel. Dosimetric indices from the nominal and worst-case plans were compared.Results: The 3F-SFO plans generally yielded D95 and D5 values in the targets that were similar to those of the MFO plans. 3F-SFO resulted in a lower dose to the oral cavity than MFO in all four patients by an average of 9.9 Gy, but the dose to the two parotids was on average 6.7 Gy higher for 3F-SFO than for MFO. 3F-SFO plans reduced the variations of dosimetric indices under uncertainties in the targets by 22.8% compared to the MFO plans. Variations of dosimetric indices under uncertainties in the organs at risk (OARs) varied between organs and between patients, although they were on average 9.2% less for the 3F-SFO plans than for the MFO plans. Compared with the MFO plans, the 2F-SFO plans showed a reduced dose to

  12. PET/CT-guided treatment planning for paediatric cancer patients: a simulation study of proton and conventional photon therapy

    Science.gov (United States)

    Brodin, N P; Björk-Eriksson, T; Birk Christensen, C; Kiil-Berthelsen, A; Aznar, M C; Hollensen, C; Markova, E; Munck af Rosenschöld, P

    2015-01-01

    Objective: To investigate the impact of including fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). Methods: Target volumes were first delineated without and subsequently re-delineated with access to 18F-FDG PET scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (3DCRT) and intensity-modulated proton therapy (IMPT). The results were evaluated by comparison of target volumes, target dose coverage parameters, normal tissue complication probability (NTCP) and estimated risk of secondary cancer (SC). Results: Considerable deviations between CT- and PET/CT-guided target volumes were seen in 3 out of the 11 patients studied. However, averaging over the whole cohort, CT or PET/CT guidance introduced no significant difference in the shape or size of the target volumes, target dose coverage, irradiated volumes, estimated NTCP or SC risk, neither for IMPT nor 3DCRT. Conclusion: Our results imply that the inclusion of PET/CT scans in the RT planning process could have considerable impact for individual patients. There were no general trends of increasing or decreasing irradiated volumes, suggesting that the long-term morbidity of RT in childhood would on average remain largely unaffected. Advances in knowledge: 18F-FDG PET-based RT planning does not systematically change NTCP or SC risk for paediatric cancer patients compared with CT only. 3 out of 11 patients had a distinct change of target volumes when PET-guided planning was introduced. Dice and mismatch metrics are not sufficient to assess the consequences of target volume differences in the context of RT. PMID:25494657

  13. Development and implementation of a non Gaussian model for the lateral dose prediction in a proton therapy treatment planning system

    Science.gov (United States)

    Bellinzona, V. E.

    2017-05-01

    Challenging issues in treatment planning system for hadrontherapy are the accurate and fast calculation of dose distribution, the reduction in memory space required to store the dose kernel of individual pencil beams and the shortening of computation time for dose optimization and calculation. In this framework, the prediction of lateral dose distributions is a topic of great interest because currently the double gaussian parametrization is typically used as approximation although other parameterizations are also available. The best accuracy for this kind of calculations can be obtained by Monte Carlo methods, at the expense of a long computing time. This work aims to present a flexible computational model for the calculation of the lateral profile of a pencil proton beam and the results of its implementation in a treatment planning system. The model calculation are compared with the currently used double gaussian approximation and the Monte Carlo calculations, and the tests are performed in water and in presence of inhomogeneities.

  14. SU-E-T-633: Preparation and Planning of a VMAT Multi - Arc Radiation Therapy Technique for Full Scalp Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, C; Bardock, A; Berkelaar, S; Gillund, D; McGee, K; Mohamed, I; Lapointe, C [British Columbia Cancer Agency, Kelowna, BC (Canada)

    2015-06-15

    Purpose: The target volume for angiosarcoma of the scalp encompasses the entire scalp. Full scalp radiotherapy (FSRT) requires careful design of required bolus, immobilization and marking of the field before the patient CT is acquired. A VMAT multi-arc technique was designed to deliver FSRT for a patient with angiosarcoma of the scalp to a dose of 6000cGy in 25 fractions. Methods: A custom bolus helmet was fabricated from a 0.5 cm thick sheet of aquaplast material, which was molded to the patient’s head. With the bolus helmet in place the patient was then positioned supine on a H&N immobilization board. A custom vaclock bag positioned on a standard headrest and a thermoplastic mask were used to immobilize the patient. Additional bolus to cover the remaining treatment area was attached to the mask. We acquired two CT scans of the patient’s head, one in treatment position and an additional scan without the immobilization mask with wires marking the treatment area that the oncologist had delineated on the patient’s skin. The second scan was registered to the first and used to define the treatment CTV. A four-arc VMAT treatment planned using Varian-Eclipse was optimized to cover the skin with a PTV margin while sparing the brain and limiting the dose to the optic apparatus and lacrimal glands. Daily treatment setup was verified using anterior and lateral kV on-board-imaging. To verify the treated dose, TLDs were positioned on the patient’s scalp during one fraction. Results: With full dose coverage to the PTV, the mean dose to the brain was less than 24 Gy. The dose measured by the TLDs (mean difference 1%, standard deviation 4%)showed excellent agreement with the treatment planning calculation. Conclusion: FSRT delivered with a bolus helmet and a VMAT multi-arc technique can be accurately delivered with high dose uniformity and conformality.

  15. SU-F-T-444: Quality Improvement Review of Radiation Therapy Treatment Planning in the Presence of Dental Implants

    Energy Technology Data Exchange (ETDEWEB)

    Parenica, H; Ford, J [Texas A& M University, College Station, TX (United States); Mavroidis, P [University of North Carolina, Chapel Hill, NC, (United States); Li, Y; Stathakis, S [Cancer Therapy and Research Center, San Antonio, TX (United States); Papanikolaou, N [University of Texas Health Science Center at San Antonio, San Antonio, TX (United States)

    2016-06-15

    Purpose: To quantify and compare the effect of metallic dental implants (MDI) on dose distributions calculated using Collapsed Cone Convolution Superposition (CCCS) algorithm or a Monte Carlo algorithm (with and without correcting for the density of the MDI). Methods: Seven previously treated patients to the head and neck region were included in this study. The MDI and the streaking artifacts on the CT images were carefully contoured. For each patient a plan was optimized and calculated using the Pinnacle3 treatment planning system (TPS). For each patient two dose calculations were performed, a) with the densities of the MDI and CT artifacts overridden (12 g/cc and 1 g/cc respectively) and b) without density overrides. The plans were then exported to the Monaco TPS and recalculated using Monte Carlo dose calculation algorithm. The changes in dose to PTVs and surrounding Regions of Interest (ROIs) were examined between all plans. Results: The Monte Carlo dose calculation indicated that PTVs received 6% lower dose than the CCCS algorithm predicted. In some cases, the Monte Carlo algorithm indicated that surrounding ROIs received higher dose (up to a factor of 2). Conclusion: Not properly accounting for dental implants can impact both the high dose regions (PTV) and the low dose regions (OAR). This study implies that if MDI and the artifacts are not appropriately contoured and given the correct density, there is potential significant impact on PTV coverage and OAR maximum doses.

  16. 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.

  17. Water equivalent thickness of immobilization devices in proton therapy planning - Modelling at treatment planning and validation by measurements with a multi-layer ionization chamber.

    Science.gov (United States)

    Fellin, Francesco; Righetto, Roberto; Fava, Giovanni; Trevisan, Diego; Amelio, Dante; Farace, Paolo

    2017-03-01

    To investigate the range errors made in treatment planning due to the presence of the immobilization devices along the proton beam path. The measured water equivalent thickness (WET) of selected devices was measured by a high-energy spot and a multi-layer ionization chamber and compared with that predicted by treatment planning system (TPS). Two treatment couches, two thermoplastic masks (both un-stretched and stretched) and one headrest were selected. At TPS, every immobilization device was modelled as being part of the patient. The following parameters were assessed: CT acquisition protocol, dose-calculation grid-sizes (1.5 and 3.0mm) and beam-entrance with respect to the devices (coplanar and non-coplanar). Finally, the potential errors produced by a wrong manual separation between treatment couch and the CT table (not present during treatment) were investigated. In the thermoplastic mask, there was a clear effect due to beam entrance, a moderate effect due to the CT protocols and almost no effect due to TPS grid-size, with 1mm errors observed only when thick un-stretched portions were crossed by non-coplanar beams. In the treatment couches the WET errors were negligible (0.5mm with a 3.0mm grid-size. In the headrest, WET errors were negligible (0.2mm). With only one exception (un-stretched mask, non-coplanar beams), the WET of all the immobilization devices was properly modelled by the TPS. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  18. Dosimetric verification in water of a Monte Carlo treatment planning tool for proton, helium, carbon and oxygen ion beams at the Heidelberg Ion Beam Therapy Center

    Science.gov (United States)

    Tessonnier, T.; Böhlen, T. T.; Ceruti, F.; Ferrari, A.; Sala, P.; Brons, S.; Haberer, T.; Debus, J.; Parodi, K.; Mairani, A.

    2017-08-01

    The introduction of ‘new’ ion species in particle therapy needs to be supported by a thorough assessment of their dosimetric properties and by treatment planning comparisons with clinically used proton and carbon ion beams. In addition to the latter two ions, helium and oxygen ion beams are foreseen at the Heidelberg Ion Beam Therapy Center (HIT) as potential assets for improving clinical outcomes in the near future. We present in this study a dosimetric validation of a FLUKA-based Monte Carlo treatment planning tool (MCTP) for protons, helium, carbon and oxygen ions for spread-out Bragg peaks in water. The comparisons between the ions show the dosimetric advantages of helium and heavier ion beams in terms of their distal and lateral fall-offs with respect to protons, reducing the lateral size of the region receiving 50% of the planned dose up to 12 mm. However, carbon and oxygen ions showed significant doses beyond the target due to the higher fragmentation tail compared to lighter ions (p and He), up to 25%. The Monte Carlo predictions were found to be in excellent geometrical agreement with the measurements, with deviations below 1 mm for all parameters investigated such as target and lateral size as well as distal fall-offs. Measured and simulated absolute dose values agreed within about 2.5% on the overall dose distributions. The MCTP tool, which supports the usage of multiple state-of-the-art relative biological effectiveness models, will provide a solid engine for treatment planning comparisons at HIT.

  19. Volumetric modulated arc therapy versus step-and-shoot intensity modulated radiation therapy in the treatment of large nerve perineural spread to the skull base: a comparative dosimetric planning study

    Energy Technology Data Exchange (ETDEWEB)

    Gorayski, Peter; Fitzgerald, Rhys; Barry, Tamara [Department of Radiation Oncology, Princess Alexandra Hospital, Woolloongabba, Queensland (Australia); Burmeister, Elizabeth [Nursing Practice Development Unit, Princess Alexandra Hospital and Research Centre for Clinical and Community Practice Innovation, Griffith University, Brisbane, Queensland (Australia); Foote, Matthew [Department of Radiation Oncology, Princess Alexandra Hospital, Woolloongabba, Queensland (Australia); Diamantina Institute, University of Queensland, Brisbane, Queensland (Australia)

    2014-06-15

    Cutaneous squamous cell carcinoma with large nerve perineural (LNPN) infiltration of the base of skull is a radiotherapeutic challenge given the complex target volumes to nearby organs at risk (OAR). A comparative planning study was undertaken to evaluate dosimetric differences between volumetric modulated arc therapy (VMAT) versus intensity modulated radiation therapy (IMRT) in the treatment of LNPN. Five consecutive patients previously treated with IMRT for LNPN were selected. VMAT plans were generated for each case using the same planning target volumes (PTV), dose prescriptions and OAR constraints as IMRT. Comparative parameters used to assess target volume coverage, conformity and homogeneity included V95 of the PTV (volume encompassed by the 95% isodose), conformity index (CI) and homogeneity index (HI). In addition, OAR maximum point doses, V20, V30, non-target tissue (NTT) point max doses, NTT volume above reference dose, monitor units (MU) were compared. IMRT and VMAT plans generated were comparable for CI (P = 0.12) and HI (P = 0.89). VMAT plans achieved better V95 (P = < 0.001) and reduced V20 and V30 by 652 cubic centimetres (cc) (28.5%) and 425.7 cc (29.1%), respectively. VMAT increased MU delivered by 18% without a corresponding increase in NTT dose. Compared with IMRT plans for LNPN, VMAT achieved comparable HI and CI.

  20. Clinical implementation of a GPU-based simplified Monte Carlo method for a treatment planning system of proton beam therapy.

    Science.gov (United States)

    Kohno, R; Hotta, K; Nishioka, S; Matsubara, K; Tansho, R; Suzuki, T

    2011-11-21

    We implemented the simplified Monte Carlo (SMC) method on graphics processing unit (GPU) architecture under the computer-unified device architecture platform developed by NVIDIA. The GPU-based SMC was clinically applied for four patients with head and neck, lung, or prostate cancer. The results were compared to those obtained by a traditional CPU-based SMC with respect to the computation time and discrepancy. In the CPU- and GPU-based SMC calculations, the estimated mean statistical errors of the calculated doses in the planning target volume region were within 0.5% rms. The dose distributions calculated by the GPU- and CPU-based SMCs were similar, within statistical errors. The GPU-based SMC showed 12.30-16.00 times faster performance than the CPU-based SMC. The computation time per beam arrangement using the GPU-based SMC for the clinical cases ranged 9-67 s. The results demonstrate the successful application of the GPU-based SMC to a clinical proton treatment planning.

  1. Fully Automated Simultaneous Integrated Boosted-Intensity Modulated Radiation Therapy Treatment Planning Is Feasible for Head-and-Neck Cancer: A Prospective Clinical Study

    Energy Technology Data Exchange (ETDEWEB)

    Wu Binbin, E-mail: binbin.wu@gunet.georgetown.edu [Department of Radiation Oncology and Molecular Radiation Science, Johns Hopkins University, Baltimore, Maryland (United States); Department of Radiation Medicine, Georgetown University Hospital, Washington, DC (United States); McNutt, Todd [Department of Radiation Oncology and Molecular Radiation Science, Johns Hopkins University, Baltimore, Maryland (United States); Zahurak, Marianna [Department of Oncology Biostatistics, Johns Hopkins University, Baltimore, Maryland (United States); Simari, Patricio [Autodesk Research, Toronto, ON (Canada); Pang, Dalong [Department of Radiation Medicine, Georgetown University Hospital, Washington, DC (United States); Taylor, Russell [Department of Computer Science, Johns Hopkins University, Baltimore, Maryland (United States); Sanguineti, Giuseppe [Department of Radiation Oncology and Molecular Radiation Science, Johns Hopkins University, Baltimore, Maryland (United States)

    2012-12-01

    Purpose: To prospectively determine whether overlap volume histogram (OVH)-driven, automated simultaneous integrated boosted (SIB)-intensity-modulated radiation therapy (IMRT) treatment planning for head-and-neck cancer can be implemented in clinics. Methods and Materials: A prospective study was designed to compare fully automated plans (APs) created by an OVH-driven, automated planning application with clinical plans (CPs) created by dosimetrists in a 3-dose-level (70 Gy, 63 Gy, and 58.1 Gy), head-and-neck SIB-IMRT planning. Because primary organ sparing (cord, brain, brainstem, mandible, and optic nerve/chiasm) always received the highest priority in clinical planning, the study aimed to show the noninferiority of APs with respect to PTV coverage and secondary organ sparing (parotid, brachial plexus, esophagus, larynx, inner ear, and oral mucosa). The sample size was determined a priori by a superiority hypothesis test that had 85% power to detect a 4% dose decrease in secondary organ sparing with a 2-sided alpha level of 0.05. A generalized estimating equation (GEE) regression model was used for statistical comparison. Results: Forty consecutive patients were accrued from July to December 2010. GEE analysis indicated that in APs, overall average dose to the secondary organs was reduced by 1.16 (95% CI = 0.09-2.33) with P=.04, overall average PTV coverage was increased by 0.26% (95% CI = 0.06-0.47) with P=.02 and overall average dose to the primary organs was reduced by 1.14 Gy (95% CI = 0.45-1.8) with P=.004. A physician determined that all APs could be delivered to patients, and APs were clinically superior in 27 of 40 cases. Conclusions: The application can be implemented in clinics as a fast, reliable, and consistent way of generating plans that need only minor adjustments to meet specific clinical needs.

  2. Image Guided Radiation Therapy (IGRT) Practice Patterns and IGRT's Impact on Workflow and Treatment Planning: Results From a National Survey of American Society for Radiation Oncology Members.

    Science.gov (United States)

    Nabavizadeh, Nima; Elliott, David A; Chen, Yiyi; Kusano, Aaron S; Mitin, Timur; Thomas, Charles R; Holland, John M

    2016-03-15

    To survey image guided radiation therapy (IGRT) practice patterns, as well as IGRT's impact on clinical workflow and planning treatment volumes (PTVs). A sample of 5979 treatment site-specific surveys was e-mailed to the membership of the American Society for Radiation Oncology (ASTRO), with questions pertaining to IGRT modality/frequency, PTV expansions, method of image verification, and perceived utility/value of IGRT. On-line image verification was defined as images obtained and reviewed by the physician before treatment. Off-line image verification was defined as images obtained before treatment and then reviewed by the physician before the next treatment. Of 601 evaluable responses, 95% reported IGRT capabilities other than portal imaging. The majority (92%) used volumetric imaging (cone-beam CT [CBCT] or megavoltage CT), with volumetric imaging being the most commonly used modality for all sites except breast. The majority of respondents obtained daily CBCTs for head and neck intensity modulated radiation therapy (IMRT), lung 3-dimensional conformal radiation therapy or IMRT, anus or pelvis IMRT, prostate IMRT, and prostatic fossa IMRT. For all sites, on-line image verification was most frequently performed during the first few fractions only. No association was seen between IGRT frequency or CBCT utilization and clinical treatment volume to PTV expansions. Of the 208 academic radiation oncologists who reported working with residents, only 41% reported trainee involvement in IGRT verification processes. Consensus guidelines, further evidence-based approaches for PTV margin selection, and greater resident involvement are needed for standardized use of IGRT practices. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Dosimetric effect of photon beam energy on volumetric modulated arc therapy treatment plan quality due to body habitus in advanced prostate cancer.

    Science.gov (United States)

    Stanley, D N; Popp, T; Ha, C S; Swanson, G P; Eng, T Y; Papanikolaou, N; Gutiérrez, A N

    2015-01-01

    The purpose of this study was to dosimetrically compare 6- and 10-MV photon beam energies in high-risk prostate cancer patients of various body habitus using a volumetric modulated arc therapy (VMAT) radiation delivery technique. The objectives of the study were to evaluate whether dosimetric differences exist and to investigate whether differences are dependent on patient body habitus. Forty patients with various body habitus who had previously received treatment to the prostate and pelvic lymph nodes with VMAT techniques were chosen. Patients were planned in the Pinnacle(3) treatment planning system with double or triple SmartArc plans with 6- and 10-MV photon energies. All patients were optimized with the same planning objectives and normalized such that 95% of the planning target volume (PTV) received the prescription dose. Patients were evaluated for PTV and organ at risk (OAR) parameters for the bladder, rectum, small bowel, penile bulb, and sigmoid colon. Metrics used for comparison were D2%, D98%, homogeneity, conformity, and dose falloff for the PTV and D(2%), D(mean), V(80%), V(60%), and V(40%) for OARs. Statistical differences were evaluated with a paired-sample Wilcoxon signed rank test with a significance level of .05. For the PTV, there were no statistically significant differences in D(mean), D(2cc), conformation number, and homogeneity index values, but the dose falloff parameters, R50 and R25, showed a median improvement of 6.7% (Phabitus; however, the improvement in dose falloff is dependent on body habitus and increases as the patient body habitus increases. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  4. Treatment planning and 3D dose verification of whole brain radiation therapy with hippocampal avoidance in rats

    Science.gov (United States)

    Yoon, S. W.; Miles, D.; Cramer, C.; Reinsvold, M.; Kirsch, D.; Oldham, M.

    2017-05-01

    Despite increasing use of stereotactic radiosurgery, whole brain radiotherapy (WBRT) continues to have a therapeutic role in a selected subset of patients. Selectively avoiding the hippocampus during such treatment (HA-WBRT) emerged as a strategy to reduce the cognitive morbidity associated with WBRT and gave rise to a recently published the phase II trial (RTOG 0933) and now multiple ongoing clinical trials. While conceptually hippocampal avoidance is supported by pre-clinical evidence showing that the hippocampus plays a vital role in memory, there is minimal pre-clinic data showing that selectively avoiding the hippocampus will reduce radiation-induced cognitive decline. Largely the lack of pre-clinical evidence can be attributed to the technical hurdles associated with delivering precise conformal treatment the rat brain. In this work we develop a novel conformal HA-WBRT technique for Wistar rats, utilizing a 225kVp micro-irradiator with precise 3D-printed radiation blocks designed to spare hippocampus while delivering whole brain dose. The technique was verified on rodent-morphic Presage® 3D dosimeters created from micro-CT scans of Wistar rats with Duke Large Field-of-View Optical Scanner (DLOS) at 1mm isotropic voxel resolution. A 4-field box with parallel opposed AP-PA and two lateral opposed fields was explored with conformal hippocampal sparing aided by 3D-printed radiation blocks. The measured DVH aligned reasonably well with that calculated from SmART Plan Monte Carlo simulations with simulated blocks for 4-field HA-WBRT with both demonstrating hippocampal sparing of 20% volume receiving less than 30% the prescription dose.

  5. KWARTA (Quality Assurance in the Radiotherapy centres of the Antwerp province): Quality control of the contract therapy machine and treatment planning system

    Energy Technology Data Exchange (ETDEWEB)

    De Ost, B.; Schaeken, B.; Vanregemorter, J. [Algemeen Ziekenhuis Middelheim, Antwerp (Belgium); Bellekens, L. [Sint-Vincentius Ziekenhuis, Antwerp (Belgium); Cardoen, R.; Pieters, D. [Medisch Instituut Sint Augustinus, Wilrijk (Belgium); Goossens, H. [Sint-Elisabeth Ziekenhuis, Turnhout (Belgium); Haest, K.; Mertens, N. [Sint Norbertus Ziekenhuis, Duffel (Belgium)

    1995-12-01

    During the first year of the provincial QA project, joint procedures were set up for the routine quality control of linear accelerators, Cobalt treatment machines and simulators. A set of standard forms was produced for use in all centres, respecting the differences in each individual machine. Since forms are now in use in all centres, the second year of the project mainly focused on the QA/QC of the contract therapy machine and treatment planning system. QC measurements for the contract therapy machines were performed in air or in a phantom. Since the output was checked with the same ionisation chamber (0.33 cc flat chamber calibrated for 50 kV) and the same type of electrometer in all centres, the results could be compared mutually and with the reference values. The major parameter groups, tested for the treatment planning system were: isodose distribution (visual control of all square fields in the database of the system), PDD data (analysing of 10 x 10 cm{sup 2}, 20 x 20 cm{sup 2}, 30 x 30 cm{sup 2} and 40 x 40 cm{sup 2} open or wedged fields), output factors, wedge and tray factors, inverse square law, geometrical testing of the digitizer - screen - printer and geometrical and densitometrical testing of the CT images - screen - printer. Between 496 and 1243 parameters were investigated in the different centres (depending on the presence of the electron data). Irregularities (0 % to 4 % of the total investigated parameters) were reported to the respective physicist.

  6. 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 ...

  7. Treatment Plan Technique and Quality for Single-Isocenter Stereotactic Ablative Radiotherapy of Multiple Lung Lesions with Volumetric-Modulated Arc Therapy or Intensity-Modulated Radiosurgery

    Science.gov (United States)

    Quan, Kimmen; Xu, Karen M.; Lalonde, Ron; Horne, Zachary D.; Bernard, Mark E.; McCoy, Chuck; Clump, David A.; Burton, Steven A.; Heron, Dwight E.

    2015-01-01

    The aim of this study is to provide a practical approach to the planning technique and evaluation of plan quality for the multi-lesion, single-isocenter stereotactic ablative radiotherapy (SABR) of the lung. Eleven patients with two or more lung lesions underwent single-isocenter volumetric-modulated arc therapy (VMAT) radiosurgery or IMRS. All plans were normalized to the target maximum dose. For each plan, all targets were treated to the same dose. Plan conformity and dose gradient were maximized with dose-control tuning structures surrounding targets. For comparison, multi-isocenter plans were retrospectively created for four patients. Conformity index (CI), homogeneity index (HI), gradient index (GI), and gradient distance (GD) were calculated for each plan. V5, V10, and V20 of the lung and organs at risk (OARs) were collected. Treatment time and total monitor units (MUs) were also recorded. One patient had four lesions and the remainder had two lesions. Six patients received VMAT and five patients received intensity-modulated radiosurgery (IMRS). For those treated with VMAT, two patients received 3-arc VMAT and four received 2-arc VMAT. For those treated with IMRS, two patients were treated with 10 and 11 beams, respectively, and the rest received 12 beams. Prescription doses ranged from 30 to 54 Gy in three to five fractions. The median prescribed isodose line was 84% (range: 80–86%). The median maximum dose was 57.1 Gy (range: 35.7–65.1 Gy). The mean combined PTV was 49.57 cm3 (range: 14.90–87.38 cm3). For single-isocenter plans, the median CI was 1.15 (range: 0.97–1.53). The median HI was 1.19 (range: 1.16–1.28). The median GI was 4.60 (range: 4.16–7.37). The median maximum radiation dose (Dmax) to total lung was 55.6 Gy (range: 35.7–62.0 Gy). The median mean radiation dose to the lung (Dmean) was 4.2 Gy (range: 1.1–9.3 Gy). The median lung V5 was 18.7% (range: 3.8–41.3%). There was no significant difference in CI, HI, GI

  8. Intensity Modulated Proton and Photon Therapy for Early Prostate Cancer With or Without Transperineal Injection of a Polyethylen Glycol Spacer: A Treatment Planning Comparison Study

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Damien C., E-mail: damien.weber@unige.ch [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Zilli, Thomas [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Vallee, Jean Paul [Department of Diagnostic Radiology, Geneva University Hospital, Geneva (Switzerland); Rouzaud, Michel; Miralbell, Raymond [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Cozzi, Luca [Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona (Switzerland)

    2012-11-01

    Purpose: Rectal toxicity is a serious adverse effect in early-stage prostate cancer patients treated with curative radiation therapy (RT). Injecting a spacer between Denonvilliers' fascia increases the distance between the prostate and the anterior rectal wall and may thus decrease the rectal radiation-induced toxicity. We assessed the dosimetric impact of this spacer with advanced delivery RT techniques, including intensity modulated RT (IMRT), volumetric modulated arc therapy (VMAT), and intensity modulated proton beam RT (IMPT). Methods and Materials: Eight prostate cancer patients were simulated for RT with or without spacer. Plans were computed for IMRT, VMAT, and IMPT using the Eclipse treatment planning system using both computed tomography spacer+ and spacer- data sets. Prostate {+-} seminal vesicle planning target volume [PTV] and organs at risk (OARs) dose-volume histograms were calculated. The results were analyzed using dose and volume metrics for comparative planning. Results: Regardless of the radiation technique, spacer injection decreased significantly the rectal dose in the 60- to 70-Gy range. Mean V{sub 70Gy} and V{sub 60Gy} with IMRT, VMAT, and IMPT planning were 5.3 {+-} 3.3%/13.9 {+-} 10.0%, 3.9 {+-} 3.2%/9.7 {+-} 5.7%, and 5.0 {+-} 3.5%/9.5 {+-} 4.7% after spacer injection. Before spacer administration, the corresponding values were 9.8 {+-} 5.4% (P=.012)/24.8 {+-} 7.8% (P=.012), 10.1 {+-} 3.0% (P=.002)/17.9 {+-} 3.9% (P=.003), and 9.7 {+-} 2.6% (P=.003)/14.7% {+-} 2.7% (P=.003). Importantly, spacer injection usually improved the PTV coverage for IMRT. With this technique, mean V{sub 70.2Gy} (P=.07) and V{sub 74.1Gy} (P=0.03) were 100 {+-} 0% to 99.8 {+-} 0.2% and 99.1 {+-} 1.2% to 95.8 {+-} 4.6% with and without Spacer, respectively. As a result of spacer injection, bladder doses were usually higher but not significantly so. Only IMPT managed to decrease the rectal dose after spacer injection for all dose levels, generally with no

  9. Treatment goals and treatment in exercise therapy.

    NARCIS (Netherlands)

    Zuijderduin, W.M.; Dekker, J.

    1994-01-01

    In the present study a quantitative description is given of treatment in exercise therapy according to Cesar and according to Mensendieck. Information was gathered from saurvey on exercise therapy in the Netherlands. Characteristics of treatment are described including treatment goals, emphasis of

  10. Using a handheld stereo depth camera to overcome limited field-of-view in simulation imaging for radiation therapy treatment planning.

    Science.gov (United States)

    Jenkins, Cesare; Xing, Lei; Yu, Amy

    2017-05-01

    A correct body contour is essential for reliable treatment planning in radiation therapy. While modern medical imaging technologies provide highly accurate patient modeling, there are times when a patient's anatomy cannot be fully captured or there is a lack of easy access to computed tomography (CT) simulation. Here, we provide a practical solution to the surface contour truncation problem by using a handheld stereo depth camera (HSDC) to obtain the missing surface anatomy and a surface-surface image registration to stich the surface data into the CT dataset for treatment planning. For a subject with truncated simulation CT images, a HSDC is used to capture the surface information of the truncated anatomy. A mesh surface model is created using a software tool provided by the camera manufacturer. A surface-to-surface registration technique is used to merge the mesh model with the CT and fill in the missing surface information thereby obtaining a complete surface model of the subject. To evaluate the accuracy of the proposed approach, experiments were performed with the following steps. First, we selected three previously treated patients and fabricated a phantom mimicking each patient using the corresponding CT images and a 3D printer. Second, we removed part of the CT images of each patient to create hypothetical cases with image truncations. Next, a HSDC was used to image the 3D-printed phantoms and the HSDC-derived surface models were registered with the hypothetically truncated CT images. The contours obtained using the approach were then compared with the ground truth contours derived from the original simulation CT without image truncation. The distance between the two contours was calculated in order to evaluate the accuracy of the method. Finally, the dosimetric impact of the approach is assessed by comparing the volume within the 95% isodose line and global maximum dose (Dmax ) computed based on the two surface contours for the breast case that exhibited

  11. WE-D-18A-01: Evaluation of Three Commercial Metal Artifact Reduction Methods for CT Simulations in Radiation Therapy Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J; Kerns, J; Nute, J; Liu, X; Stingo, F; Followill, D; Mirkovic, D; Howell, R; Kry, S [UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    Purpose: To evaluate three commercial metal artifact reduction methods (MAR) in the context of radiation therapy treatment planning. Methods: Three MAR strategies were evaluated: Philips O-MAR, monochromatic imaging using Gemstone Spectral Imaging (GSI) dual energy CT, and monochromatic imaging with metal artifact reduction software (GSIMARs). The Gammex RMI 467 tissue characterization phantom with several metal rods and two anthropomorphic phantoms (pelvic phantom with hip prosthesis and head phantom with dental fillings), were scanned with and without (baseline) metals. Each MAR method was evaluated based on CT number accuracy, metal size accuracy, and reduction in the severity of streak artifacts. CT number difference maps between the baseline and metal scan images were calculated, and the severity of streak artifacts was quantified using the percentage of pixels with >40 HU error (“bad pixels”). Results: Philips O-MAR generally reduced HU errors in the RMI phantom. However, increased errors and induced artifacts were observed for lung materials. GSI monochromatic 70keV images generally showed similar HU errors as 120kVp imaging, while 140keV images reduced errors. GSI-MARs systematically reduced errors compared to GSI monochromatic imaging. All imaging techniques preserved the diameter of a stainless steel rod to within ±1.6mm (2 pixels). For the hip prosthesis, O-MAR reduced the average % bad pixels from 47% to 32%. For GSI 140keV imaging, the percent of bad pixels was reduced from 37% to 29% compared to 120kVp imaging, while GSI-MARs further reduced it to 12%. For the head phantom, none of the MAR methods were particularly successful. Conclusion: The three MAR methods all improve CT images for treatment planning to some degree, but none of them are globally effective for all conditions. The MAR methods were successful for large metal implants in a homogeneous environment (hip prosthesis) but were not successful for the more complicated case of dental

  12. SU-E-T-572: Beam Characteristics and Treatment Planning Commissioning for a New Proton Therapy Unit

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, T; Sun, B; Grantham, K; Santanam, L; Goddu, S; Klein, E [Washington University, St. Louis, MO (United States)

    2014-06-01

    Purpose: A single-room proton system, the Mevion S250, was introduced into the arena of proton radiotherapy by Mevion Medical Systems. The first unit was installed and operates at the S. Lee Kling Proton Therapy Center at Barnes-Jewish Hospital. The objective of this abstract is to report the system's beam characteristics and Eclipse commissioning. Methods: Commissioning data were acquired for modelling longitudinal fluence, virtual source position, effective source position, source size and Bragg peaks in Eclipse. Stoichiometric CT calibration was generated via ICRU44 human. Spread-out Bragg peaks (SOBP) were measured with Parallel Plate Chamber and profiles with solid state detector for model validation. Heterogeneity effects were measured with bone and lung inserts in the beam line. RT dose was computed in a virtual water phantom, and exported from Eclipse to compare with measurements at various depths and axis. SOBPs were fine-tuned with partial shining correction and entry correction to match measurements. Output factor was measured for each individual field with an ADCL ion chamber in a water tank and fitted to a polynomial function to cross-check the monitor unit verification. Results: Ranges of all 24 options were measured within ±1mm tolerance. Modulations met a ±1mm or ±2% tolerance. SOBP flatness met a ±3% tolerance. Distal fall off (80%-20%) were measured between 6mm and 7mm for all options. Virtual source positions varied between 177cm and 195cm, decreasing with field size and range. SOBP generated by Eclipse agreed with measurements within ±3% in the entry region, and ±1%/±1mm in other regions. Sanity check for output achieved 5% accuracy in 98% of cases. Conclusion: The commissioning of the first Mevions S250 proton therapy system met specifications. The unit has been put in clinical operation since 12/17/2013.

  13. ACR Appropriateness Criteria for external beam radiation therapy treatment planning for clinically localized prostate cancer, part II of II

    Directory of Open Access Journals (Sweden)

    Nicholas G. Zaorsky, MD

    2017-07-01

    Conclusions: External beam radiation is a key component of the curative management of T1 and T2 prostate cancer. By combining the most recent medical literature, these Appropriateness Criteria can aid clinicians in determining the appropriate treatment delivery and personalized approaches for individual patients.

  14. Conversion of helical tomotherapy plans to step-and-shoot IMRT plans--Pareto front evaluation of plans from a new treatment planning system.

    Science.gov (United States)

    Petersson, Kristoffer; Ceberg, Crister; Engström, Per; Benedek, Hunor; Nilsson, Per; Knöös, Tommy

    2011-06-01

    The resulting plans from a new type of treatment planning system called SharePlan have been studied. This software allows for the conversion of treatment plans generated in a TomoTherapy system for helical delivery, into plans deliverable on C-arm linear accelerators (linacs), which is of particular interest for clinics with a single TomoTherapy unit. The purpose of this work was to evaluate and compare the plans generated in the SharePlan system with the original TomoTherapy plans and with plans produced in our clinical treatment planning system for intensity-modulated radiation therapy (IMRT) on C-arm linacs. In addition, we have analyzed how the agreement between SharePlan and TomoTherapy plans depends on the number of beams and the total number of segments used in the optimization. Optimized plans were generated for three prostate and three head-and-neck (H&N) cases in the TomoTherapy system, and in our clinical treatment planning systems (TPS) used for IMRT planning with step-and-shoot delivery. The TomoTherapy plans were converted into step-and-shoot IMRT plans in SharePlan. For each case, a large number of Pareto optimal plans were created to compare plans generated in SharePlan with plans generated in the Tomotherapy system and in the clinical TPS. In addition, plans were generated in SharePlan for the three head-and-neck cases to evaluate how the plan quality varied with the number of beams used. Plans were also generated with different number of beams and segments for other patient cases. This allowed for an evaluation of how to minimize the number of required segments in the converted IMRT plans without compromising the agreement between them and the original TomoTherapy plans. The plans made in SharePlan were as good as or better than plans from our clinical system, but they were not as good as the original TomoTherapy plans. This was true for both the head-and-neck and the prostate cases, although the differences between the plans for the latter were

  15. 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.

  16. User's manual of a supporting system for treatment planning in boron neutron capture therapy. JAERI computational dosimetry system

    CERN Document Server

    Kumada, H

    2002-01-01

    A boron neutron capture therapy (BNCT) with epithermal neutron beam is expected to treat effectively for malignant tumor that is located deeply in the brain. It is indispensable to estimate preliminarily the irradiation dose in the brain of a patient in order to perform the epithermal neutron beam BNCT. Thus, the JAERI Computational Dosimetry System (JCDS), which can calculate the dose distributions in the brain, has been developed. JCDS is a software that creates a 3-dimensional head model of a patient by using CT and MRI images and that generates a input data file automatically for calculation neutron flux and gamma-ray dose distribution in the brain by the Monte Carlo code: MCNP, and that displays the dose distribution on the head model for dosimetry by using the MCNP calculation results. JCDS has any advantages as follows; By treating CT data and MRI data which are medical images, a detail three-dimensional model of patient's head is able to be made easily. The three-dimensional head image is editable to ...

  17. Development of Monte Carlo based real-time treatment planning system with fast calculation algorithm for boron neutron capture therapy.

    Science.gov (United States)

    Takada, Kenta; Kumada, Hiroaki; Liem, Peng Hong; Sakurai, Hideyuki; Sakae, Takeji

    2016-12-01

    We simulated the effect of patient displacement on organ doses in boron neutron capture therapy (BNCT). In addition, we developed a faster calculation algorithm (NCT high-speed) to simulate irradiation more efficiently. We simulated dose evaluation for the standard irradiation position (reference position) using a head phantom. Cases were assumed where the patient body is shifted in lateral directions compared to the reference position, as well as in the direction away from the irradiation aperture. For three groups of neutron (thermal, epithermal, and fast), flux distribution using NCT high-speed with a voxelized homogeneous phantom was calculated. The three groups of neutron fluxes were calculated for the same conditions with Monte Carlo code. These calculated results were compared. In the evaluations of body movements, there were no significant differences even with shifting up to 9mm in the lateral directions. However, the dose decreased by about 10% with shifts of 9mm in a direction away from the irradiation aperture. When comparing both calculations in the phantom surface up to 3cm, the maximum differences between the fluxes calculated by NCT high-speed with those calculated by Monte Carlo code for thermal neutrons and epithermal neutrons were 10% and 18%, respectively. The time required for NCT high-speed code was about 1/10th compared to Monte Carlo calculation. In the evaluation, the longitudinal displacement has a considerable effect on the organ doses. We also achieved faster calculation of depth distribution of thermal neutron flux using NCT high-speed calculation code. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  18. Motion-Compensated Estimation of Delivered Dose during External BeamRadiation Therapy: Implementation in Philips’ Pinnacle3 Treatment Planning System

    NARCIS (Netherlands)

    Bharat, S.; Parikh, P.; Noel, C.; Meltsner, M.; Bzdusek, K.; Kaus, M.

    2012-01-01

    Purpose: Recent research efforts investigating dose escalation techniques for three-dimensional conformal radiation therapy (3D CRT) andintensity modulated radiation therapy (IMRT) have demonstrated great benefit when high-dose hypofractionated treatment schemes are implemented16,21. The use of

  19. Linac-based extracranial radiosurgery with Elekta volumetric modulated arc therapy and an anatomy-based treatment planning system: Feasibility and initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Cilla, Savino, E-mail: savinocilla@gmail.com [Medical Physics Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II”, Università Cattolica del Sacro Cuore, Campobasso (Italy); Deodato, Francesco; Macchia, Gabriella; Digesù, Cinzia [Radiotherapy Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II”, Università Cattolica del Sacro Cuore, Campobasso (Italy); Ianiro, Anna; Viola, Pietro; Craus, Maurizio [Medical Physics Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II”, Università Cattolica del Sacro Cuore, Campobasso (Italy); Valentini, Vincenzo [Radiotherapy Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II”, Università Cattolica del Sacro Cuore, Campobasso (Italy); Radiation Oncology Unit, Policlinico Universitario “A. Gemelli”, Università Cattolica del Sacro Cuore, Roma (Italy); Piermattei, Angelo [Medical Physics Unit, Policlinico Universitario “A. Gemelli”, Università Cattolica del Sacro Cuore, Roma (Italy); Morganti, Alessio G. [Radiation Oncology Unit, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, S. Orsola-Malpighi Hospital, University of Bologna, Bologna (Italy)

    2016-07-01

    We reported our initial experience in using Elekta volumetric modulated arc therapy (VMAT) and an anatomy-based treatment planning system (TPS) for single high-dose radiosurgery (SRS-VMAT) of liver metastases. This study included a cohort of 12 patients treated with a 26-Gy single fraction. Single-arc VMAT plans were generated with Ergo++ TPS. The prescription isodose surface (IDS) was selected to fulfill the 2 following criteria: 95% of planning target volume (PTV) reached 100% of the prescription dose and 99% of PTV reached a minimum of 90% of prescription dose. A 1-mm multileaf collimator (MLC) block margin was added around the PTV. For a comparison of dose distributions with literature data, several conformity indexes (conformity index [CI], conformation number [CN], and gradient index [GI]) were calculated. Treatment efficiency and pretreatment dosimetric verification were assessed. Early clinical data were also reported. Our results reported that target and organ-at-risk objectives were met for all patients. Mean and maximum doses to PTVs were on average 112.9% and 121.5% of prescribed dose, respectively. A very high degree of dose conformity was obtained, with CI, CN, and GI average values equal to 1.29, 0.80, and 3.63, respectively. The beam-on-time was on average 9.3 minutes, i.e., 0.36 min/Gy. The mean number of monitor units was 3162, i.e., 121.6 MU/Gy. Pretreatment verification (3%-3 mm) showed an optimal agreement with calculated values; mean γ value was 0.27 and 98.2% of measured points resulted with γ < 1. With a median follow-up of 16 months complete response was observed in 12/14 (86%) lesions; partial response was observed in 2/14 (14%) lesions. No radiation-induced liver disease (RILD) was observed in any patients as well no duodenal ulceration or esophagitis or gastric hemorrhage. In conclusion, this analysis demonstrated the feasibility and the appropriateness of high-dose single-fraction SRS-VMAT in liver metastases performed with Elekta

  20. Motion-Compensated Estimation of Delivered Dose during External BeamRadiation Therapy: Implementation in Philips’ Pinnacle3 Treatment Planning System

    OpenAIRE

    Bharat, S.; Parikh, P.; Noel, C; Meltsner, M.; Bzdusek, K.; Kaus, M.

    2012-01-01

    Purpose: Recent research efforts investigating dose escalation techniques for three-dimensional conformal radiation therapy (3D CRT) andintensity modulated radiation therapy (IMRT) have demonstrated great benefit when high-dose hypofractionated treatment schemes are implemented16,21. The use of these paradigms emphasizes the importanceof smaller treatment margins to avoid high dose to surrounding normal tissue or organs at risk (OARs). However, tighter margins may leadto under-dosage of the t...

  1. Fast and accurate Monte Carlo modeling of a kilovoltage X-ray therapy unit using a photon-source approximation for treatment planning in complex media

    Directory of Open Access Journals (Sweden)

    B Zeinali-Rafsanjani

    2015-01-01

    Full Text Available To accurately recompute dose distributions in chest-wall radiotherapy with 120 kVp kilovoltage X-rays, an MCNP4C Monte Carlo model is presented using a fast method that obviates the need to fully model the tube components. To validate the model, half-value layer (HVL, percentage depth doses (PDDs and beam profiles were measured. Dose measurements were performed for a more complex situation using thermoluminescence dosimeters (TLDs placed within a Rando phantom. The measured and computed first and second HVLs were 3.8, 10.3 mm Al and 3.8, 10.6 mm Al, respectively. The differences between measured and calculated PDDs and beam profiles in water were within 2 mm/2% for all data points. In the Rando phantom, differences for majority of data points were within 2%. The proposed model offered an approximately 9500-fold reduced run time compared to the conventional full simulation. The acceptable agreement, based on international criteria, between the simulations and the measurements validates the accuracy of the model for its use in treatment planning and radiobiological modeling studies of superficial therapies including chest-wall irradiation using kilovoltage beam.

  2. Fast and accurate Monte Carlo modeling of a kilovoltage X-ray therapy unit using a photon-source approximation for treatment planning in complex media.

    Science.gov (United States)

    Zeinali-Rafsanjani, B; Mosleh-Shirazi, M A; Faghihi, R; Karbasi, S; Mosalaei, A

    2015-01-01

    To accurately recompute dose distributions in chest-wall radiotherapy with 120 kVp kilovoltage X-rays, an MCNP4C Monte Carlo model is presented using a fast method that obviates the need to fully model the tube components. To validate the model, half-value layer (HVL), percentage depth doses (PDDs) and beam profiles were measured. Dose measurements were performed for a more complex situation using thermoluminescence dosimeters (TLDs) placed within a Rando phantom. The measured and computed first and second HVLs were 3.8, 10.3 mm Al and 3.8, 10.6 mm Al, respectively. The differences between measured and calculated PDDs and beam profiles in water were within 2 mm/2% for all data points. In the Rando phantom, differences for majority of data points were within 2%. The proposed model offered an approximately 9500-fold reduced run time compared to the conventional full simulation. The acceptable agreement, based on international criteria, between the simulations and the measurements validates the accuracy of the model for its use in treatment planning and radiobiological modeling studies of superficial therapies including chest-wall irradiation using kilovoltage beam.

  3. Sleep Eduction: Treatment & Therapy

    Science.gov (United States)

    ... Diagnosis Treatment Jet Lag Overview Symptoms & Self Test Treatment Narcolepsy Overview & Facts Symptoms Self-Tests & Diagnosis Treatment Restless Legs Syndrome Overview & Facts Causes & Symptoms Self- ...

  4. Behaviour therapy for obesity treatment considering approved drug therapy.

    Science.gov (United States)

    Kossmann, Beate; Ulle, Tanja; Kahl, Kai G; Wasem, Jürgen; Aidelsburger, Pamela

    2008-05-29

    media in conjunction with personal support within the groups. However, analyses of the inter-group comparisons offer no statistically significant difference. However, analyses of the inter-group comparisons offer no statistically significant difference. Comparative analyses confirm the effectiveness of behaviour therapy in combination with additional drug treatment when compared to behaviour therapy alone. In all the studies presented here, relevant changes in weight of -5% to -10% are only partially achieved. High weight losses of less than -10% were found among the intervention group in two of the studies. One study reported a weight loss of -11.4% with the "group therapy" intervention method, while another study reported a weight loss of -11.2% with the "behaviour therapy plus drug treatment" intervention method. Studies with a subsequent follow-up period indicate a clear weight loss at the end of the intervention followed by a renewed weight gain towards the end of the follow-up period. For the evaluation of economic, social-ethical or legal aspects we could not identify any studies. A comparative assessment among the studies proved difficult due to their heterogeneous nature. Little conformity can be detected in either the contents of the behaviour therapy or in the treatment plans. The length of the follow-up periods also varies from study to study. Many studies only analyze weight changes within one group or for the entire study population. However, the results of these analyses all indicate a significant weight loss at the end of the intervention. Some effects of behaviour therapy on a reduction in weight can be shown. However, relevant weight changes of -5% to -10% are only achieved to a certain extent. The extremely heterogeneous nature of the interventions makes a comparison of the study results very difficult. A trend can be detected indicates that those treatments which offer drug treatment in addition to behaviour therapy are more effective than behaviour

  5. Evaluation of volumetric modulated arc therapy (VMAT with Oncentra MasterPlan® for the treatment of head and neck cancer

    Directory of Open Access Journals (Sweden)

    Koelbl Oliver

    2010-11-01

    Full Text Available Abstract Background Several comparison studies have shown the capability of VMAT to achieve similar or better plan quality as IMRT, while reducing the treatment time. The experience of VMAT in a multi vendor environment is limited. We compared the plan quality and performance of VMAT to IMRT and we investigate the effects of varying various user-selectable parameters. Methods IMRT, single arc VMAT and dual arc VMAT were compared for four different head-and-neck tumors. For VMAT, the effect of varying gantry angle spacing and treatment time on the plan quality was investigated. A comparison of monitor units and treatment time was performed. Results IMRT and dual arc VMAT achieved a similar plan quality, while single arc could not provide an acceptable plan quality. Increasing the number of control points does not improve the plan quality. Dual arc VMAT delivery time is about 30% of IMRT delivery time. Conclusions Dual arc VMAT is a fast and accurate technique for the treatment of head and neck cancer. It applies similar number of MUs as IMRT, but the treatment time is strongly reduced, maintaining similar or better dose conformity to the PTV and OAR sparing.

  6. 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...

  7. Treatment planning for restorative implantology.

    Science.gov (United States)

    Boyce, Ricardo A; Klemons, Gary

    2015-04-01

    In this article, current literature on fixed and removable prosthodontics is reviewed along with evidence-based systematic reviews, including advice from those in the dental profession with years of experience, which help restorative dentists manage and treat their cases successfully. Treatment planning for restorative implantology should be looked at in 4 sections: (1) review of past medical history, (2) oral examination and occlusion, (3) dental imaging (ie, cone-beam computed tomography), and (4) fixed versus removable prosthodontics. These 4 concepts of treatment planning, along with proper surgical placements of the implant(s), result in successful cases. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Assessment tool for planning fallback Tomotherapy treatment plans; Evaluacion de la herramienta fallback planning para planes de tratamiento de tomoterapia

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Rubio, P.; Rodriguez Romero, R.; Montes Uruen, A.

    2015-07-01

    Interruption of radiotherapy treatments in an increase the total time of the same to the detriment of tumour control. In centers that have a unique special unit as the TomoTherapy, is emphasized the difficulty to resume treatment at another unit, since the technique of helical TomoTherapy is not portable to conventional accelerators and therefore requires the planning of new dosimetry distributions emulating the initially obtained and accepted. This work evaluates the ability of an automatic planning tool to mimic TomoTherapy plans. (Author)

  9. Behaviour therapy for obesity treatment considering approved drug therapy

    Directory of Open Access Journals (Sweden)

    Wasem, Jürgen

    2008-05-01

    interventions of media alone as well as through the intervention of media in conjunction with personal support within the groups. However, analyses of the inter-group comparisons offer no statistically significant difference. However, analyses of the inter-group comparisons offer no statistically significant difference. Comparative analyses confirm the effectiveness of behaviour therapy in combination with additional drug treatment when compared to behaviour therapy alone.In all the studies presented here, relevant changes in weight of -5% to -10% are only partially achieved. High weight losses of less than -10% were found among the intervention group in two of the studies. One study reported a weight loss of -11.4% with the “group therapy” intervention method, while another study reported a weight loss of -11.2% with the “behaviour therapy plus drug treatment” intervention method. Studies with a subsequent follow-up period indicate a clear weight loss at the end of the intervention followed by a renewed weight gain towards the end of the follow-up period.For the evaluation of economic, social-ethical or legal aspects we could not identify any studies. Discussion: A comparative assessment among the studies proved difficult due to their heterogeneous nature. Little conformity can be detected in either the contents of the behaviour therapy or in the treatment plans. The length of the follow-up periods also varies from study to study. Many studies only analyze weight changes within one group or for the entire study population. However, the results of these analyses all indicate a significant weight loss at the end of the intervention. Conclusion: Some effects of behaviour therapy on a reduction in weight can be shown. However, relevant weight changes of -5% to -10% are only achieved to a certain extent. The extremely heterogeneous nature of the interventions makes a comparison of the study results very difficult. A trend can be detected indicates that those treatments

  10. A treatment planning and delivery comparison of volumetric modulated arc therapy with or without flattening filter for gliomas, brain metastases, prostate, head/neck and early stage lung cancer

    DEFF Research Database (Denmark)

    Gasic, Daniel; Ohlhues, Lars; Brodin, N. Patrik

    2014-01-01

    compared to flattening filter beams (i.e. standard, STD) for several patient groups. We hypothesize that the treatment plan quality is comparable while the treatment delivery time of volumetric modulated arc therapy (VMAT) is considerably shorter using FFF beams, especially for stereotactic treatments....... METHODS: A total of 120 patients treated for head and neck (H&N) tumors, high-grade glioma, prostate cancer, early stage lung cancer and intra-cranial metastatic disease (both single and multiple metastases) were included in the study. For each cohort, 20 consecutive patients were selected. The plans were...... generated using STD- and FFF-VMAT for both 6 MV and 10 MV, and were compared with respect to plan quality, monitor units and delivery time using Wilcoxon signed rank tests. RESULTS: For H&N and high-grade gliomas, there was a significant difference in homogeneity index in favor for STD-VMAT (p

  11. The use and QA of biologically related models for treatment planning: short report of the TG-166 of the therapy physics committee of the AAPM.

    Science.gov (United States)

    Allen Li, X; Alber, Markus; Deasy, Joseph O; Jackson, Andrew; Ken Jee, Kyung-Wook; Marks, Lawrence B; Martel, Mary K; Mayo, Charles; Moiseenko, Vitali; Nahum, Alan E; Niemierko, Andrzej; Semenenko, Vladimir A; Yorke, Ellen D

    2012-03-01

    Treatment planning tools that use biologically related models for plan optimization and/or evaluation are being introduced for clinical use. A variety of dose-response models and quantities along with a series of organ-specific model parameters are included in these tools. However, due to various limitations, such as the limitations of models and available model parameters, the incomplete understanding of dose responses, and the inadequate clinical data, the use of biologically based treatment planning system (BBTPS) represents a paradigm shift and can be potentially dangerous. There will be a steep learning curve for most planners. The purpose of this task group is to address some of these relevant issues before the use of BBTPS becomes widely spread. In this report, the authors (1) discuss strategies, limitations, conditions, and cautions for using biologically based models and parameters in clinical treatment planning; (2) demonstrate the practical use of the three most commonly used commercially available BBTPS and potential dosimetric differences between biologically model based and dose-volume based treatment plan optimization and evaluation; (3) identify the desirable features and future directions in developing BBTPS; and (4) provide general guidelines and methodology for the acceptance testing, commissioning, and routine quality assurance (QA) of BBTPS.

  12. TU-G-BRD-01: Quantifying the Effectiveness of the Physics Pre-Treatment Plan Review for Detecting Errors in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gopan, O; Novak, A; Zeng, J; Ford, E [University of Washington, Seattle, WA (United States)

    2015-06-15

    Purpose: Physics pre-treatment plan review is crucial to safe radiation oncology treatments. Studies show that most errors originate in treatment planning, which underscores the importance of physics plan review. As a QA measure the physics review is of fundamental importance and is central to the profession of medical physics. However, little is known about its effectiveness. More hard data are needed. The purpose of this study was to quantify the effectiveness of physics review with the goal of improving it. Methods: This study analyzed 315 “potentially serious” near-miss incidents within an institutional incident learning system collected over a two-year period. 139 of these originated prior to physics review and were found at the review or after. Incidents were classified as events that: 1)were detected by physics review, 2)could have been detected (but were not), and 3)could not have been detected. Category 1 and 2 events were classified by which specific check (within physics review) detected or could have detected the event. Results: Of the 139 analyzed events, 73/139 (53%) were detected or could have been detected by the physics review; although, 42/73 (58%) were not actually detected. 45/73 (62%) errors originated in treatment planning, making physics review the first step in the workflow that could detect the error. Two specific physics checks were particularly effective (combined effectiveness of >20%): verifying DRRs (8/73) and verifying isocenter (7/73). Software-based plan checking systems were evaluated and found to have potential effectiveness of 40%. Given current data structures, software implementations of some tests such as isocenter verification check would be challenging. Conclusion: Physics plan review is a key safety measure and can detect majority of reported events. However, a majority of events that potentially could have been detected were NOT detected in this study, indicating the need to improve the performance of physics review.

  13. Pancreatic cancer planning: Complex conformal vs modulated therapies

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Katherine L. [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Witek, Matthew E. [Department of Radiation Oncology, University of Wisconsin School of Medicine School of Medicine and Public Health, Madison, WI (United States); Chen, Hongyu [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Showalter, Timothy N. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Bar-Ad, Voichita [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Harrison, Amy S., E-mail: amy.harrison@jefferson.edu [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States)

    2016-07-01

    To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT. All volumes were approved by a single observer in accordance with Radiation Therapy Oncology Group (RTOG) Pancreas Contouring Atlas. Plans included tumor/tumor bed and regional lymph nodes to 45 Gy; with tumor/tumor bed boosted to 50.4 Gy, at least 95% of planning target volume (PTV) received the prescription dose. Dose-volume histograms (DVH) for multiple end points, treatment planning, and delivery time were assessed. Complex 3DCRT, IMRT, and VMAT plans significantly (p < 0.05) decreased mean kidney dose, mean liver dose, liver (V{sub 30}, V{sub 35}), stomach (D{sub 10}%), stomach (V{sub 45}), mean right kidney dose, and right kidney (V{sub 15}) as compared with the simple 4-field plans that are most commonly reported in the literature. IMRT plans resulted in decreased mean liver dose, liver (V{sub 35}), and left kidney (V{sub 15}, V{sub 18}, V{sub 20}). VMAT plans decreased small bowel (D{sub 10}%, D{sub 15}%), small bowel (V{sub 35}, V{sub 45}), stomach (D{sub 10}%, D{sub 15}%), stomach (V{sub 35}, V{sub 45}), mean liver dose, liver (V{sub 35}), left kidney (V{sub 15}, V{sub 18}, V{sub 20}), and right kidney (V{sub 18}, V{sub 20}). VMAT plans significantly decreased small bowel (D{sub 10}%, D{sub 15}%), left kidney (V{sub 20}), and stomach (V{sub 45}) as compared with IMRT plans. Treatment planning and delivery times were most efficient for simple 4-field box and VMAT. Excluding patient setup and imaging, average

  14. Treatment planning study of Volumetric Modulated Arc Therapy and three dimensional field-in-field techniques for left chest-wall cancers with regional lymph nodes.

    Science.gov (United States)

    Xu, Heping; Hatcher, Gillian

    2016-01-01

    This study aims to investigate whether there are dosimetric advantages to using VMAT (Volumetric Modulated Arc Therapy) for left-sided chest-wall patients over the three-dimensional conformal field-in-field (FinF) technique. There is a lack of dosimetric studies dedicated for chest-wall patients. Potential dosimetric advantage could be obtained using VMAT due to complex geometry of PTVs (Planning Target Volumes) and OARs (Organs at Risk) in chest-wall and lymph nodes. VMAT and FinF plans were generated and evaluated based on DVHs (Dose Volume Histograms) for both PTVs and OARs for 22 left-sided chest-wall patients with involved regional nodes. PTV HIs (Homogeneity Indices) and CIs (Conformity Indices), and EUDs (Equivalent Uniform Doses) for PTVs and OARs were also evaluated for comparisons between VMAT and FinF. FinF planning met PTV criteria adequately in all cases except two. In these two cases, VMAT was able to meet PTV criteria adequately. VMAT demonstrated significant reduction in left lung V 20 Gy in chest-wall patients compared to FinF plans. The volumes of the right lung and right breast receiving 5 Gy were much higher in VMAT than those in FinF for all patients. Compared to the FinF technique, there is a generally limited benefit using VMAT for left-sided chest-wall patients due to large low-dose-bath to OARs with insignificant improvement in PTV coverage. In case where FinF planning cannot meet dose constrains, VMAT provides a viable option. The use of VMAT planning over the FinF technique in chest-wall cancers should be carefully analyzed on an individual basis.

  15. Magnetic Resonance Imaging-Based Target Volume Delineation in Radiation Therapy Treatment Planning for Brain Tumors Using Localized Region-Based Active Contour

    Energy Technology Data Exchange (ETDEWEB)

    Aslian, Hossein [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Sadeghi, Mahdi [Agricultural, Medical and Industrial Research School, Karaj (Iran, Islamic Republic of); Mahdavi, Seied Rabie [Department of Medical Physics, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Babapour Mofrad, Farshid [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Astarakee, Mahdi, E-mail: M-Astarakee@Engineer.com [Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Khaledi, Navid [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Fadavi, Pedram [Department of Radiation Oncology, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2013-09-01

    Purpose: To evaluate the clinical application of a robust semiautomatic image segmentation method to determine the brain target volumes in radiation therapy treatment planning. Methods and Materials: A local robust region-based algorithm was used on MRI brain images to study the clinical target volume (CTV) of several patients. First, 3 oncologists delineated CTVs of 10 patients manually, and the process time for each patient was calculated. The averages of the oncologists’ contours were evaluated and considered as reference contours. Then, to determine the CTV through the semiautomatic method, a fourth oncologist who was blind to all manual contours selected 4-8 points around the edema and defined the initial contour. The time to obtain the final contour was calculated again for each patient. Manual and semiautomatic segmentation were compared using 3 different metric criteria: Dice coefficient, Hausdorff distance, and mean absolute distance. A comparison also was performed between volumes obtained from semiautomatic and manual methods. Results: Manual delineation processing time of tumors for each patient was dependent on its size and complexity and had a mean (±SD) of 12.33 ± 2.47 minutes, whereas it was 3.254 ± 1.7507 minutes for the semiautomatic method. Means of Dice coefficient, Hausdorff distance, and mean absolute distance between manual contours were 0.84 ± 0.02, 2.05 ± 0.66 cm, and 0.78 ± 0.15 cm, and they were 0.82 ± 0.03, 1.91 ± 0.65 cm, and 0.7 ± 0.22 cm between manual and semiautomatic contours, respectively. Moreover, the mean volume ratio (=semiautomatic/manual) calculated for all samples was 0.87. Conclusions: Given the deformability of this method, the results showed reasonable accuracy and similarity to the results of manual contouring by the oncologists. This study shows that the localized region-based algorithms can have great ability in determining the CTV and can be appropriate alternatives for manual approaches in brain cancer.

  16. SU-F-T-152: Experimental Validation and Calculation Benchmark for a Commercial Monte Carlo Pencil BeamScanning Proton Therapy Treatment Planning System in Heterogeneous Media

    Energy Technology Data Exchange (ETDEWEB)

    Lin, L; Huang, S; Kang, M; Ainsley, C; Simone, C; McDonough, J; Solberg, T [University of Pennsylvania, Philadelphia, PA (United States)

    2016-06-15

    Purpose: Eclipse AcurosPT 13.7, the first commercial Monte Carlo pencil beam scanning (PBS) proton therapy treatment planning system (TPS), was experimentally validated for an IBA dedicated PBS nozzle in the CIRS 002LFC thoracic phantom. Methods: A two-stage procedure involving the use of TOPAS 1.3 simulations was performed. First, Geant4-based TOPAS simulations in this phantom were experimentally validated for single and multi-spot profiles at several depths for 100, 115, 150, 180, 210 and 225 MeV proton beams, using the combination of a Lynx scintillation detector and a MatriXXPT ionization chamber array. Second, benchmark calculations were performed with both AcurosPT and TOPAS in a phantom identical to the CIRS 002LFC, with the exception that the CIRS bone/mediastinum/lung tissues were replaced with similar tissues that are predefined in AcurosPT (a limitation of this system which necessitates the two stage procedure). Results: Spot sigmas measured in tissue were in agreement within 0.2 mm of TOPAS simulation for all six energies, while AcurosPT was consistently found to have larger spot sigma (<0.7 mm) than TOPAS. Using absolute dose calibration by MatriXXPT, the agreements between profiles measurements and TOPAS simulation, and calculation benchmarks are over 97% except near the end of range using 2 mm/2% gamma criteria. Overdosing and underdosing were observed at the low and high density side of tissue interfaces, respectively, and these increased with increasing depth and decreasing energy. Near the mediastinum/lung interface, the magnitude can exceed 5 mm/10%. Furthermore, we observed >5% quenching effect in the conversion of Lynx measurements to dose. Conclusion: We recommend the use of an ionization chamber array in combination with the scintillation detector to measure absolute dose and relative PBS spot characteristics. We also recommend the use of an independent Monte Carlo calculation benchmark for the commissioning of a commercial TPS. Partially

  17. Automatic planning of head and neck treatment plans

    DEFF Research Database (Denmark)

    Hazell, Irene; Bzdusek, Karl; Kumar, Prashant

    2016-01-01

    Treatment planning is time-consuming and the outcome depends on the person performing the optimization. A system that automates treatment planning could potentially reduce the manual time required for optimization and could also pro-vide a method to reduce the variation between persons performing...... treatment plans were reoptimized with the Auto-Planning module. Comparison of the two types of treatment plans were performed using DVH metrics and a blinded clinical evaluation by two senior radiation oncologists using a scale from one to six. Both evaluations investigated dose coverage of target and dose...

  18. Commissioning of a Monte Carlo treatment planning system for clinical use in radiation therapy; Evaluacion de un sistema de planificacion Monte Carlo de uso clinico para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Zucca Aparcio, D.; Perez Moreno, J. M.; Fernandez Leton, P.; Garcia Ruiz-Zorrila, J.

    2016-10-01

    The commissioning procedures of a Monte Carlo treatment planning system (MC) for photon beams from a dedicated stereotactic body radiosurgery (SBRT) unit has been reported in this document. XVMC has been the MC Code available in the treatment planning system evaluated (BrainLAB iPlan RT Dose) which is based on Virtual Source Models that simulate the primary and scattered radiation, besides the electronic contamination, using gaussian components for whose modelling are required measurements of dose profiles, percentage depth dose and output factors, performed both in water and in air. The dosimetric accuracy of the particle transport simulation has been analyzed by validating the calculations in homogeneous and heterogeneous media versus measurements made under the same conditions as the dose calculation, and checking the stochastic behaviour of Monte Carlo calculations when using different statistical variances. Likewise, it has been verified how the planning system performs the conversion from dose to medium to dose to water, applying the stopping power ratio water to medium, in the presence of heterogeneities where this phenomenon is relevant, such as high density media (cortical bone). (Author)

  19. Pediatric radiotherapy planning and treatment

    CERN Document Server

    Olch, Arthur J

    2013-01-01

    "This is a very well-written and -organized book covering the planning and delivery aspects unique to pediatric radiotherapy. The author is a respected and well-known medical physicist with extensive pediatric radiotherapy experience. … a very useful book for any clinical physicist treating pediatric cases and seeking contextual and historical perspective. … a great reference for medical physicists who may not see many pediatric cases and can look to this text as a one-stop shop for not only a comprehensive overview, but detailed explanation for specific pediatric disease sites. Overall, it is a great addition to the reference library of any radiation therapy physicist."-Medical Physics, April 2014.

  20. SU-E-T-549: A Combinatorial Optimization Approach to Treatment Planning with Non-Uniform Fractions in Intensity Modulated Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Papp, D; Unkelbach, J [Massachusetts General Hospital, Boston, MA (United States)

    2014-06-01

    Purpose: Non-uniform fractionation, i.e. delivering distinct dose distributions in two subsequent fractions, can potentially improve outcomes by increasing biological dose to the target without increasing dose to healthy tissues. This is possible if both fractions deliver a similar dose to normal tissues (exploit the fractionation effect) but high single fraction doses to subvolumes of the target (hypofractionation). Optimization of such treatment plans can be formulated using biological equivalent dose (BED), but leads to intractable nonconvex optimization problems. We introduce a novel optimization approach to address this challenge. Methods: We first optimize a reference IMPT plan using standard techniques that delivers a homogeneous target dose in both fractions. The method then divides the pencil beams into two sets, which are assigned to either fraction one or fraction two. The total intensity of each pencil beam, and therefore the physical dose, remains unchanged compared to the reference plan. The objectives are to maximize the mean BED in the target and to minimize the mean BED in normal tissues, which is a quadratic function of the pencil beam weights. The optimal reassignment of pencil beams to one of the two fractions is formulated as a binary quadratic optimization problem. A near-optimal solution to this problem can be obtained by convex relaxation and randomized rounding. Results: The method is demonstrated for a large arteriovenous malformation (AVM) case treated in two fractions. The algorithm yields a treatment plan, which delivers a high dose to parts of the AVM in one of the fractions, but similar doses in both fractions to the normal brain tissue adjacent to the AVM. Using the approach, the mean BED in the target was increased by approximately 10% compared to what would have been possible with a uniform reference plan for the same normal tissue mean BED.

  1. 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.

  2. Failure mode and effect analysis oriented to risk-reduction interventions in intraoperative electron radiation therapy: the specific impact of patient transportation, automation, and treatment planning availability.

    Science.gov (United States)

    López-Tarjuelo, Juan; Bouché-Babiloni, Ana; Santos-Serra, Agustín; Morillo-Macías, Virginia; Calvo, Felipe A; Kubyshin, Yuri; Ferrer-Albiach, Carlos

    2014-11-01

    Industrial companies use failure mode and effect analysis (FMEA) to improve quality. Our objective was to describe an FMEA and subsequent interventions for an automated intraoperative electron radiotherapy (IOERT) procedure with computed tomography simulation, pre-planning, and a fixed conventional linear accelerator. A process map, an FMEA, and a fault tree analysis are reported. The equipment considered was the radiance treatment planning system (TPS), the Elekta Precise linac, and TN-502RDM-H metal-oxide-semiconductor-field-effect transistor in vivo dosimeters. Computerized order-entry and treatment-automation were also analyzed. Fifty-seven potential modes and effects were identified and classified into 'treatment cancellation' and 'delivering an unintended dose'. They were graded from 'inconvenience' or 'suboptimal treatment' to 'total cancellation' or 'potentially wrong' or 'very wrong administered dose', although these latter effects were never experienced. Risk priority numbers (RPNs) ranged from 3 to 324 and totaled 4804. After interventions such as double checking, interlocking, automation, and structural changes the final total RPN was reduced to 1320. FMEA is crucial for prioritizing risk-reduction interventions. In a semi-surgical procedure like IOERT double checking has the potential to reduce risk and improve quality. Interlocks and automation should also be implemented to increase the safety of the procedure. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. SU-F-T-448: Use of Mixed Photon Energy Beam in Volumetric Modulated Arc Therapy (VMAT) Treatment Plan for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Manigandan, D; Kumar, M; Mohandas, P; Puri, A; Bhalla, N [Fortis Cancer Institute, Mohali, Punjab (India)

    2016-06-15

    Purpose: To study the impact of different photon beam combination during VMAT planning and treatment delivery. Methods: Five prostate patients with no nodal involvement were chosen for the study and only prostate was considered as target (7920cGy/44fractions). In each case, three different VMAT plans were generated with two arcs (200°–160°&160°–200°). First plan used only 6MV in both arcs (6X-6X) and second utilized 6MV&15MV (6X-15X), whereas third one used 15MV&15MV (15X-15X). For consistency, all the plans were generated by the same planner using Monaco− treatment planning system (V5.1) for Elekta Synergy− linear accelerator with 1cm leaf-width. For plan comparison, target mean dose, conformity index (CI)=Planning target volume (PTV) covered by 95% of prescription dose/PTV were analyzed. Mean doses of bladder, rectum, left femur and right femur were analyzed. Integral dose (liter-Gray) to normal tissue (patient volume minus PTV), total monitor unit (MU) required to deliver a plan and gamma pass rate for each plan was analyzed. Results: The CI for PTV was 0.9937±0.0037, 0.9917±0.0033, and 0.9897±0.0048 for 6X-6X, 6X-15X and 15X-15X, respectively. Mean dose to target slightly increases with the decrease of energy. Mean doses to bladder were 3546.23±692.13cGy, 3487.43±715.53cGy and 3504.40±683.1cGy for 6X-6X, 6X-15X and 15X-15X, respectively. Mean doses to rectum were 4294.60±309.5cGy, 4277.07±279.93cGy and 4290.77±379.07cGy. Mean doses to left femur were 2737.13±545.93cGy, 2668.67±407.12cGy and 2416.77±300.73cGy and mean doses to the right femur were 2682.70±460.81cGy, 2722.58±541.92cGy and 2598.57±481.83cGy. Higher Integral doses to normal tissue observed for 6X-6X (163.06±24.6 Litre-Gray) followed by 6X-15X (154.35±24.74 Litre-Gray) and 15X-15X (145.84±26.03 Litre-Gray). Average MU required to deliver one fraction was 680.75±72.09, 634.81±95.07 and 605.06±114.65. Gamma pass rates were 99.83±0.21, 99.53±0.27 and 99.2±0

  4. 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...

  5. Treatment planning in Class III malocclusion.

    Science.gov (United States)

    McIntyre, Grant T

    2004-01-01

    In Class III malocclusion, the overjet is reduced and may be reversed, with one or more incisor teeth in lingual crossbite. In the early mixed dentition, and in older patients with mild skeletal discrepancies, orthodontic treatment usually involves proclining the maxilliary anterior teeth into positive overjet. When the permanent dentition has established, orthodontic therapy is usually aimed at compensating for the underlying mild-moderate Class III skeletal discrepancy by proclining and retroclining the maxillary and mandibular incisors, respectively. In contrast, adolescent and non-growing patients with severe Class III skeletal discrepancies require a combination of orthodontic treatment and orthognathic surgery to correct the underlying skeletal pattern. Adolescent patients with moderately severe skeletal discrepancies require careful treatment planning because they are often at the limits of orthodontic compensation, and further mandibular growth may prevent a stable Class I occlusion from being maintained with growth. In this situation, treatment should be limited to aligning the maxillary arch, accepting that orthognathic surgery will be required to correct the underlying Class III skeletal discrepancy when skeletal growth has been completed. This article will inform dental professionals about the aetiology, assessment, diagnosis and treatment of patients with Class III malocclusions. Specifically, the types of orthodontic treatment that can be completed at the various stages of dental development and skeletal growth will be discussed.

  6. Monte Carlo Treatment Planning for Advanced Radiotherapy

    DEFF Research Database (Denmark)

    Cronholm, Rickard

    This Ph.d. project describes the development of a workflow for Monte Carlo Treatment Planning for clinical radiotherapy plans. The workflow may be utilized to perform an independent dose verification of treatment plans. Modern radiotherapy treatment delivery is often conducted by dynamically...... modulating the intensity of the field during the irradiation. The workflow described has the potential to fully model the dynamic delivery, including gantry rotation during irradiation, of modern radiotherapy. Three corner stones of Monte Carlo Treatment Planning are identified: Building, commissioning...

  7. Image Guided Radiation Therapy (IGRT) Practice Patterns and IGRT's Impact on Workflow and Treatment Planning: Results From a National Survey of American Society for Radiation Oncology Members

    Energy Technology Data Exchange (ETDEWEB)

    Nabavizadeh, Nima, E-mail: nabaviza@ohsu.edu [Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon (United States); Elliott, David A. [Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon (United States); Chen, Yiyi [Division of Biostatistics, Department of Public Health and Preventative Medicine, Oregon Health & Science University, Portland, Oregon (United States); Kusano, Aaron S. [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Mitin, Timur; Thomas, Charles R.; Holland, John M. [Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon (United States)

    2016-03-15

    Purpose: To survey image guided radiation therapy (IGRT) practice patterns, as well as IGRT's impact on clinical workflow and planning treatment volumes (PTVs). Methods and Materials: A sample of 5979 treatment site–specific surveys was e-mailed to the membership of the American Society for Radiation Oncology (ASTRO), with questions pertaining to IGRT modality/frequency, PTV expansions, method of image verification, and perceived utility/value of IGRT. On-line image verification was defined as images obtained and reviewed by the physician before treatment. Off-line image verification was defined as images obtained before treatment and then reviewed by the physician before the next treatment. Results: Of 601 evaluable responses, 95% reported IGRT capabilities other than portal imaging. The majority (92%) used volumetric imaging (cone-beam CT [CBCT] or megavoltage CT), with volumetric imaging being the most commonly used modality for all sites except breast. The majority of respondents obtained daily CBCTs for head and neck intensity modulated radiation therapy (IMRT), lung 3-dimensional conformal radiation therapy or IMRT, anus or pelvis IMRT, prostate IMRT, and prostatic fossa IMRT. For all sites, on-line image verification was most frequently performed during the first few fractions only. No association was seen between IGRT frequency or CBCT utilization and clinical treatment volume to PTV expansions. Of the 208 academic radiation oncologists who reported working with residents, only 41% reported trainee involvement in IGRT verification processes. Conclusion: Consensus guidelines, further evidence-based approaches for PTV margin selection, and greater resident involvement are needed for standardized use of IGRT practices.

  8. Incorporating quantitative single photon emission computed tomography into radiation therapy treatment planning for lung cancer: impact of attenuation and scatter correction on the single photon emission computed tomography-weighted mean dose and functional lung segmentation.

    Science.gov (United States)

    Yin, Lingshu; Shcherbinin, Sergey; Celler, Anna; Thompson, Anna; Fua, Tsien-Fei; Liu, Mitchell; Duzenli, Cheryl; Gill, Brad; Sheehan, Finbar; Powe, John; Worsley, Daniel; Marks, Lawrence; Moiseenko, Vitali

    2010-10-01

    To assess the impact of attenuation and scatter corrections on the calculation of single photon emission computed tomography (SPECT)-weighted mean dose (SWMD) and functional volume segmentation as applied to radiation therapy treatment planning for lung cancer. Nine patients with lung cancer underwent a SPECT lung perfusion scan. For each scan, four image sets were reconstructed using the ordered subsets expectation maximization method with attenuation and scatter corrections ranging from none to a most comprehensive combination of attenuation corrections and direct scatter modeling. Functional volumes were segmented in each reconstructed image using 10%, 20%, …, 90% of maximum SPECT intensity as a threshold. Systematic effects of SPECT reconstruction methods on treatment planning using functional volume were studied by calculating size and spatial agreements of functional volumes, and V(20) for functional volume from actual treatment plans. The SWMD was calculated for radiation beams with a variety of possible gantry angles and field sizes. Functional volume segmentation is sensitive to the particular method of SPECT reconstruction used. Large variations in functional volumes, as high as >50%, were observed in SPECT images reconstructed with different attenuation/scatter corrections. However, SWMD was less sensitive to the type of scatter corrections. SWMD was consistent within 2% for all reconstructions as long as computed tomography-based attenuation correction was used. When using perfusion SPECT images during treatment planning optimization/evaluation, the SWMD may be the preferred figure of merit, as it is less affected by reconstruction technique, compared with threshold-based functional volume segmentation. 2010 Elsevier Inc. All rights reserved.

  9. Combination therapy of three-dimensional (3D) visualisation operative treatment planning system and US-guided percutaneous microwave ablation in larger renal cell carcinomas (D ≥ 4 cm): preliminary results.

    Science.gov (United States)

    Li, Xin; Yu, Jie; Liang, Ping; Yu, Xiaoling; Cheng, Zhigang; Han, Zhiyu; Huang, Hui; Duan, Shaobo; Zheng, Jiasheng

    2016-12-07

    To analyse the clinical outcomes of combination therapy of three-dimensional (3D) visualisation operative treatment planning system and US-guided percutaneous microwave ablation (PMWA) in larger renal cell carcinomas (RCCs) (D ≥ 4 cm). The results from 20 patients with 20 larger RCCs treated with a 3D visualisation operative treatment planning system and US-guided PMWA were reviewed retrospectively. The patients were followed up by contrast-enhanced images at 1, 3, and 6 months and every 6 months thereafter. The outcomes of overall survival and local tumour progression rate were statistically analysed. The median follow-up period was 26 months. The mean time of ablation for one tumour was 1.1 ± 0.3 sessions. The average number of ablation points of one tumour was 4.5 ± 0.9. The mean output power of ablation was 50.50 ± 2.2 W. The mean time of ablation for one tumour was 1374.4 ± 391.1 s. Artificial ascites was used in 12 (60%) tumours adjacent to the intestinal tract, and thermal monitoring system was used in all tumours (100%). Technical effectiveness and metastasis-free status were achieved in all tumours. The 1- and 2-year local tumour progression rates were both 5%. The cancer-specific survival rate and 2-year overall survival rates were both 100%. No severe major complications occurred. There was no significant difference in creatinine or urea nitrogen before or 3 days after ablation. Combination therapy of 3D visualisation operative treatment planning system and US-guided PMWA appeared to be a safe and effective technique for the management of larger RCCs, which could improve clinical efficacy.

  10. Investigating the potential of three-dimensional treatment planning.

    Science.gov (United States)

    Fraass, B A

    3-D treatment planning has received a great deal of attention in the radiation therapy community over the last several years. This new technology makes use of the continuous improvements in computer hardware and graphics capabilities, along with major improvements in treatment planning software, to provide a fully three dimensional simulation of the patient, radiation beams, and dose distributions which are used for radiation therapy of various cancers. With these capabilities, the physician and treatment planner may now optimize the radiation beams used to treat the patient much more effectively than in the past, when only a limited description of the patient, beams, and doses was available. This paper describes several of the new capabilities of these 3-D planning systems, some research studies which are currently being performed to evaluate the usefulness of the new technology, and finally some of the costs associated with its implementation.

  11. [Multicenter trial for sudden hearing loss therapy - planning and concept].

    Science.gov (United States)

    Plontke, S K; Girndt, M; Meisner, C; Probst, R; Oerlecke, I; Richter, M; Steighardt, J; Dreier, G; Weber, A; Baumann, I; Plößl, S; Löhler, J; Laszig, R; Werner, J A; Rahne, T

    2016-04-01

    Systemic steroids are widely used worldwide as a standard of care for primary therapy of idiopathic sudden sensorineural hearing loss (ISSHL). The German ISSHL guideline recommends high-dose steroids for primary therapy of ISSHL, without evidence from randomized controlled trials (RCTs). The rationale for the treatment of ISSHL using high dose steroids is only based on retrospective cohort studies.This article describes the planning and initiation of a multicenter, national, randomized, controlled clinical trial entitled Efficacy and safety of high dose glucocorticosteroid treatment for idiopathic sudden sensorineural hearing loss - a three-armed, randomized, triple-blind, multicenter trial (HODOKORT). This clinical trial aims to compare standard dose with two types of high-dose steroids for primary systemic therapy with respect to their efficacy in improving hearing, and thus communication ability, in patients with idiopathic sudden sensorineural hearing loss.This study is funded by the "Clinical Trials with High Patient Relevance" research program in the health research framework of the German Federal Ministry of Education and Research. It is one of two studies by the German Study Center of Clinical Trials of the German Society of Otorhinolaryngology, Head and Neck Surgery (DSZ-HNO). Planning and initiation was done in cooperation with the DSZ-HNO, the Coordination Center of Clinical Trials of the Martin-Luther-University Halle-Wittenberg, and the Study Center of the University Hospital Freiburg.

  12. Adaptive Stereotactic Body Radiation Therapy Planning for Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yujiao [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Zhang, Fan [Occupational and Environmental Safety Office, Duke University Medical Center, Durham, North Carolina (United States); Yoo, David S.; Kelsey, Chris R. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Cai, Jing, E-mail: jing.cai@duke.edu [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2013-09-01

    Purpose: To investigate the dosimetric effects of adaptive planning on lung stereotactic body radiation therapy (SBRT). Methods and Materials: Forty of 66 consecutive lung SBRT patients were selected for a retrospective adaptive planning study. CBCT images acquired at each fraction were used for treatment planning. Adaptive plans were created using the same planning parameters as the original CT-based plan, with the goal to achieve comparable comformality index (CI). For each patient, 2 cumulative plans, nonadaptive plan (P{sub NON}) and adaptive plan (P{sub ADP}), were generated and compared for the following organs-at-risks (OARs): cord, esophagus, chest wall, and the lungs. Dosimetric comparison was performed between P{sub NON} and P{sub ADP} for all 40 patients. Correlations were evaluated between changes in dosimetric metrics induced by adaptive planning and potential impacting factors, including tumor-to-OAR distances (d{sub T-OAR}), initial internal target volume (ITV{sub 1}), ITV change (ΔITV), and effective ITV diameter change (Δd{sub ITV}). Results: 34 (85%) patients showed ITV decrease and 6 (15%) patients showed ITV increase throughout the course of lung SBRT. Percentage ITV change ranged from −59.6% to 13.0%, with a mean (±SD) of −21.0% (±21.4%). On average of all patients, P{sub ADP} resulted in significantly (P=0 to .045) lower values for all dosimetric metrics. Δd{sub ITV}/d{sub T-OAR} was found to correlate with changes in dose to 5 cc (ΔD5cc) of esophagus (r=0.61) and dose to 30 cc (ΔD30cc) of chest wall (r=0.81). Stronger correlations between Δd{sub ITV}/d{sub T-OAR} and ΔD30cc of chest wall were discovered for peripheral (r=0.81) and central (r=0.84) tumors, respectively. Conclusions: Dosimetric effects of adaptive lung SBRT planning depend upon target volume changes and tumor-to-OAR distances. Adaptive lung SBRT can potentially reduce dose to adjacent OARs if patients present large tumor volume shrinkage during the treatment.

  13. Disregarding RBE variation in treatment plan comparison may lead to bias in favor of proton plans.

    Science.gov (United States)

    Wedenberg, Minna; Toma-Dasu, Iuliana

    2014-09-01

    Currently in proton radiation therapy, a constant relative biological effectiveness (RBE) equal to 1.1 is assumed. The purpose of this study is to evaluate the impact of disregarding variations in RBE on the comparison of proton and photon treatment plans. Intensity modulated treatment plans using photons and protons were created for three brain tumor cases with the target situated close to organs at risk. The proton plans were optimized assuming a standard RBE equal to 1.1, and the resulting linear energy transfer (LET) distribution for the plans was calculated. In the plan evaluation, the effect of a variable RBE was studied. The RBE model used considers the RBE variation with dose, LET, and the tissue specific parameter α/β of photons. The plan comparison was based on dose distributions, DVHs and normal tissue complication probabilities (NTCPs). Under the assumption of RBE=1.1, higher doses to the tumor and lower doses to the normal tissues were obtained for the proton plans compared to the photon plans. In contrast, when accounting for RBE variations, the comparison showed lower doses to the tumor and hot spots in organs at risk in the proton plans. These hot spots resulted in higher estimated NTCPs in the proton plans compared to the photon plans. Disregarding RBE variations might lead to suboptimal proton plans giving lower effect in the tumor and higher effect in normal tissues than expected. For cases where the target is situated close to structures sensitive to hot spot doses, this trend may lead to bias in favor of proton plans in treatment plan comparisons.

  14. Multicatheter interstitial brachytherapy versus intensity modulated external beam therapy for accelerated partial breast irradiation: A comparative treatment planning study with respect to dosimetry of organs at risk.

    Science.gov (United States)

    Major, Tibor; Stelczer, Gábor; Pesznyák, Csilla; Mészáros, Norbert; Polgár, Csaba

    2017-01-01

    To dosimetrically compare multicatheter interstitial brachytherapy (MIBT) and intensity modulated radiotherapy (IMRT) for accelerated partial breast irradiation (APBI) with special focus on dose to normal tissues and organs at risk (OAR-s). Thirty-four patients with early stage breast cancer treated with MIBT were selected for the study. For each patient an additional IMRT treatment plan was created using the same CT data and contours as used in MIBT plans. OAR-s included ipsilateral non-target and contralateral breast, lung of both sides, skin, ribs and heart for left sided lesions. The CTV was created from the outlined lumpectomy cavity with a total margin (surgical+radiation) of 20mm in six main directions. The PTV in IMRT plans was generated from CTV with an addition of isotropic 5mm margin. The prescribed dose was 30.1Gy with 7×4.3Gy fractionation for both techniques. From dose-volume histograms quality parameters including volumes receiving a given dose (e.g. V100, V90, V50) and doses to specified volumes (e.g. D0.01cm(3), D0.1cm(3), D1cm(3)) were calculated and compared. Except for high dose, non-target breast received less dose with MIBT. V90 was 3.6% vs. 4.8% and V50 was 13.7% vs. 25.5% for MIBT and IMRT, respectively. Ipsilateral lung was spared better with MIBT. Mean lung dose was 5.1% vs. 7.1%, [Formula: see text] was 39.0% vs. 54.3% and V5 was 32.9% vs. 41.7% in favour of MIBT. For left sided lesions the heart was generally irradiated by larger doses with MIBT. Mean heart dose was 4.5% vs. 2.0% and [Formula: see text] was 18.3% vs. 19.7%, correspondingly. Volumetric maximal skin doses were similar, but regarding dose to 0.1cm(3) and 1cm(3) of most exposed volume MIBT provided significantly less doses (76.6% vs. 94.4% and 60.2% vs. 87.8%, respectively). Ribs received less dose with MIBT with values of 45.6% vs. 69.3% for [Formula: see text] and 1.4% vs. 4.2cm(3) for V50. Dose to contralateral breast and lung was low with both techniques. No significant

  15. Evaluation of a commercial biologically based IMRT treatment planning system.

    Science.gov (United States)

    Semenenko, Vladimir A; Reitz, Bodo; Day, Ellen; Qi, X Sharon; Miften, Moyed; Li, X Allen

    2008-12-01

    A new inverse treatment planning system (TPS) for external beam radiation therapy with high energy photons is commercially available that utilizes both dose-volume-based cost functions and a selection of cost functions which are based on biological models. The purpose of this work is to evaluate quality of intensity-modulated radiation therapy (IMRT) plans resulting from the use of biological cost functions in comparison to plans designed using a traditional TPS employing dose-volume-based optimization. Treatment planning was performed independently at two institutions. For six cancer patients, including head and neck (one case from each institution), prostate, brain, liver, and rectal cases, segmental multileaf collimator IMRT plans were designed using biological cost functions and compared with clinically used dose-based plans for the same patients. Dose-volume histograms and dosimetric indices, such as minimum, maximum, and mean dose, were extracted and compared between the two types of treatment plans. Comparisons of the generalized equivalent uniform dose (EUD), a previously proposed plan quality index (fEUD), target conformity and heterogeneity indices, and the number of segments and monitor units were also performed. The most prominent feature of the biologically based plans was better sparing of organs at risk (OARs). When all plans from both institutions were combined, the biologically based plans resulted in smaller EUD values for 26 out of 33 OARs by an average of 5.6 Gy (range 0.24 to 15 Gy). Owing to more efficient beam segmentation and leaf sequencing tools implemented in the biologically based TPS compared to the dose-based TPS, an estimated treatment delivery time was shorter in most (five out of six) cases with some plans showing up to 50% reduction. The biologically based plans were generally characterized by a smaller conformity index, but greater heterogeneity index compared to the dose-based plans. Overall, compared to plans based on dose

  16. Tuberculosis treatment outcomes: directly observed therapy compared with self-administered therapy.

    Science.gov (United States)

    Jasmer, Robert M; Seaman, Christopher B; Gonzalez, Leah C; Kawamura, L Masae; Osmond, Dennis H; Daley, Charles L

    2004-09-01

    Effective treatment of tuberculosis requires adherence to a minimum of 6 months treatment with multiple drugs. To improve adherence and cure rates, directly observed therapy is recommended for the treatment of pulmonary tuberculosis. We compared treatment outcomes among all culture-positive patients treated for active pulmonary tuberculosis (n = 372) in San Francisco County, California from 1998 through 2000. Patients treated by directly observed therapy at the start of therapy (n = 149) had a significantly higher cure rate compared with patients treated by self-administered therapy (n = 223) (the sum of bacteriologic cure and completion of treatment, 97.8% versus 88.6%, p < 0.002), and decreased tuberculosis-related mortality (0% vs. 5.5%, p = 0.002). Rates of treatment failure, relapse, and acquired drug resistance were similar between the two groups. Forty-four percent of patients who received self-administered therapy had risk factors for nonadherence and should have been assigned to directly observed therapy. We conclude that treatment plans that emphasize directly observed therapy from the start of therapy have the greatest success in improving tuberculosis treatment outcomes.

  17. An Analysis of Plan Robustness for Esophageal Tumors: Comparing Volumetric Modulated Arc Therapy Plans and Spot Scanning Proton Planning

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Samantha, E-mail: samantha.warren@oncology.ox.ac.uk [Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, Gray Laboratories, University of Oxford, Oxford (United Kingdom); Partridge, Mike [Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, Gray Laboratories, University of Oxford, Oxford (United Kingdom); Bolsi, Alessandra; Lomax, Anthony J. [Centre for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); Hurt, Chris [Wales Cancer Trials Unit, School of Medicine, Heath Park, Cardiff (United Kingdom); Crosby, Thomas [Velindre Cancer Centre, Velindre Hospital, Cardiff (United Kingdom); Hawkins, Maria A. [Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, Gray Laboratories, University of Oxford, Oxford (United Kingdom)

    2016-05-01

    Purpose: Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. Methods and Materials: For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV){sub 50Gy} or PTV{sub 62.5Gy} (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose–volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. Results: SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D{sub 98} was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D{sub 98} was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D{sub 98} was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D{sub 98} was lower by 0.3% to 2.2% of the prescribed GTV dose. Conclusions: The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup

  18. Ectopic pregnancy treatment by combination therapy

    Directory of Open Access Journals (Sweden)

    Cymbaluk-Płoska Aneta

    2016-01-01

    Full Text Available Detectability of early stages of ectopic pregnancies has increased due to improvements in ultrasonographic and biochemical techniques. Since the patients’ future procreative plans must be taken into consideration when commencing treatment, the goal of this work was to compare the effects of treatment methods and their impact on fertility. The study included 91 patients treated surgically for ectopic pregnancy. The choice of treatment depended on patients’ general condition, ultrasonographic evaluation and serum level of beta-hCG. A combination of laparoscopic and conservative systemic treatment was applied in 70% of cases. More rapid beta-hCG reduction was noted when laparoscopy and intra-oviductal injection of hyperosmolar glucose or methotrexate (MTX were combined with intramuscular administration of MTX at a dose of 50 mg/m2. Follow-up examination of 66 patients revealed that the greatest number of spontaneous pregnancies (48% resulted after this combination therapy. We conclude that this combination treatment is safe and provides satisfactory results in terms of future fertility.

  19. Ectopic pregnancy treatment by combination therapy.

    Science.gov (United States)

    Cymbaluk-Płoska, Aneta; Chudecka-Głaz, Anita; Kuźniak, Sławomir; Menkiszak, Janusz

    2016-01-01

    Detectability of early stages of ectopic pregnancies has increased due to improvements in ultrasonographic and biochemical techniques. Since the patients' future procreative plans must be taken into consideration when commencing treatment, the goal of this work was to compare the effects of treatment methods and their impact on fertility. The study included 91 patients treated surgically for ectopic pregnancy. The choice of treatment depended on patients' general condition, ultrasonographic evaluation and serum level of beta-hCG. A combination of laparoscopic and conservative systemic treatment was applied in 70% of cases. More rapid beta-hCG reduction was noted when laparoscopy and intra-oviductal injection of hyperosmolar glucose or methotrexate (MTX) were combined with intramuscular administration of MTX at a dose of 50 mg/m2. Follow-up examination of 66 patients revealed that the greatest number of spontaneous pregnancies (48%) resulted after this combination therapy. We conclude that this combination treatment is safe and provides satisfactory results in terms of future fertility.

  20. Interactive Decision-Support Tool for Risk-Based Radiation Therapy Plan Comparison for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Brodin, N. Patrik; Maraldo, Maja V.; Aznar, Marianne C.

    2014-01-01

    PURPOSE: To present a novel tool that allows quantitative estimation and visualization of the risk of various relevant normal tissue endpoints to aid in treatment plan comparison and clinical decision making in radiation therapy (RT) planning for Hodgkin lymphoma (HL). METHODS AND MATERIALS...... and a volumetric modulated arc therapy plan for a patient with mediastinal HL. CONCLUSION: This multiple-endpoint decision-support tool provides quantitative risk estimates to supplement the clinical judgment of the radiation oncologist when comparing different RT options....... of dose-response curves to drive the reoptimization of a volumetric modulated arc therapy treatment plan for an HL patient with head-and-neck involvement. We also use this decision-support tool to visualize and quantitatively evaluate the trade-off between a 3-dimensional conformal RT plan...

  1. WE-D-BRA-01: FEATURED PRESENTATION and BEST IN PHYSICS (THERAPY): Predicting Potentially Problematic VMAT Treatment Plans Before Patient Specific QA Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Elguindi, S; Ezzell, G; Gagneur, J [Mayo Clinic Arizona, Phoenix, AZ (United States)

    2015-06-15

    Purpose: Several promising IMRT QA tools have been developed in recent years to combat problems found in the lack of sensitivity in planar dose measurements analyzed using consensus gamma analysis criteria. The increased complexity and added information with such devices adds not only increased time, but new challenges in determining endpoints for pass/fail criteria. Using a large cohort of previously measured planar IMRT QA data, it may be possible to correlate potentially problematic plans with calculated plan metrics that can be done a priori, such that these tools can be used only in clinically relevant situations. Methods: 90 previously measured, clinically delivered VMAT plans were exported in DICOM RT format. Using a Matlab program, plan metrics were computed based on a previously developed set of equations (Du et al. 2014). These metrics included MU-weighted beam irregularity, which quantifies an MLC shape’s deviation from that of a circle. Machine delivery parameters such as MU delivered per degree and leaf movement in millimeters per MU were also calculated. Based on a previous analysis of 394 IMRT QA measurements, a “failing” plan was defined as one with less than 85% gamma pass rate when computed at 1% dose difference and 2 mm distance to agreement; 16 of the 90 plans were identified as failing Results: A ROC curve was generated with an AUC of 0.9409. All 16 outliers were detected with a specificity of 85.1% when using a threshold value based on a linear combination of the MU-weighted plan irregularity and the leaf speed in mm/degree (average MU delivered per degree multiplied by average leaf movement in mm per MU). Conclusion: This data supports that potentially problematic VMAT plans can possibly be predicted before measurement by assessing the MU-weighted irregularity of the MLC shapes combined with the averaged leaf speed of the MLC.

  2. Monitoring Hazardous Fuels Treatments: Southeast Regional Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this document is to provide technical guidance on monitoring activities to refuge staff involved in planning and conducting hazardous fuel treatments....

  3. Nanotechnology Cancer Therapy and Treatment

    Science.gov (United States)

    Nanotechnology offers the means to target therapies directly and selectively to cancerous cells and neoplasms. With these tools, clinicians can safely and effectively deliver chemotherapy, radiotherapy, and the next generation of immuno- and gene therapi

  4. Behavioral Therapy, Incentives Enhance Addiction Treatment

    Science.gov (United States)

    ... Research News From NIH Behavioral Therapy, Incentives Enhance Addiction Treatment Past Issues / Summer 2006 Table of Contents ... that people who are trying to end their addiction to marijuana can benefit from a treatment program ...

  5. Improving treatment plan evaluation with automation

    Science.gov (United States)

    Covington, Elizabeth L.; Chen, Xiaoping; Younge, Kelly C.; Lee, Choonik; Matuszak, Martha M.; Kessler, Marc L.; Keranen, Wayne; Acosta, Eduardo; Dougherty, Ashley M.; Filpansick, Stephanie E.; Moran, Jean M.

    2017-01-01

    The goal of this work is to evaluate the effectiveness of Plan-Checker Tool (PCT) which was created to improve first-time plan quality, reduce patient delays, increase the efficiency of our electronic workflow, and standardize and automate the physics plan review in the treatment planning system (TPS). PCT uses an application programming interface to check and compare data from the TPS and treatment management system (TMS). PCT includes a comprehensive checklist of automated and manual checks that are documented when performed by the user as part of a plan readiness check for treatment. Prior to and during PCT development, errors identified during the physics review and causes of patient treatment start delays were tracked to prioritize which checks should be automated. Nineteen of 33checklist items were automated, with data extracted with PCT. There was a 60% reduction in the number of patient delays in the six months after PCT release. PCT was successfully implemented for use on all external beam treatment plans in our clinic. While the number of errors found during the physics check did not decrease, automation of checks increased visibility of errors during the physics check, which led to decreased patient delays. The methods used here can be applied to any TMS and TPS that allows queries of the database. PMID:27929478

  6. First steps towards a fast-neutron therapy planning program

    Directory of Open Access Journals (Sweden)

    Garny Sylvia

    2011-11-01

    Full Text Available Abstract Background The Monte Carlo code GEANT4 was used to implement first steps towards a treatment planning program for fast-neutron therapy at the FRM II research reactor in Garching, Germany. Depth dose curves were calculated inside a water phantom using measured primary neutron and simulated primary photon spectra and compared with depth dose curves measured earlier. The calculations were performed with GEANT4 in two different ways, simulating a simple box geometry and splitting this box into millions of small voxels (this was done to validate the voxelisation procedure that was also used to voxelise the human body. Results In both cases, the dose distributions were very similar to those measured in the water phantom, up to a depth of 30 cm. In order to model the situation of patients treated at the FRM II MEDAPP therapy beamline for salivary gland tumors, a human voxel phantom was implemented in GEANT4 and irradiated with the implemented MEDAPP neutron and photon spectra. The 3D dose distribution calculated inside the head of the phantom was similar to the depth dose curves in the water phantom, with some differences that are explained by differences in elementary composition. The lateral dose distribution was studied at various depths. The calculated cumulative dose volume histograms for the voxel phantom show the exposure of organs at risk surrounding the tumor. Conclusions In order to minimize the dose to healthy tissue, a conformal treatment is necessary. This can only be accomplished with the help of an advanced treatment planning system like the one developed here. Although all calculations were done for absorbed dose only, any biological dose weighting can be implemented easily, to take into account the increased radiobiological effectiveness of neutrons compared to photons.

  7. Emergency Planning for Municipal Wastewater Treatment Facilities.

    Science.gov (United States)

    Lemon, R. A.; And Others

    This manual for the development of emergency operating plans for municipal wastewater treatment systems was compiled using information provided by over two hundred municipal treatment systems. It covers emergencies caused by natural disasters, civil disorders and strikes, faulty maintenance, negligent operation, and accidents. The effects of such…

  8. Comparison of step and shoot IMRT treatment plans generated by three inverse treatment planning systems; Comparacion de tratamientos de IMRT estatica generados por tres sistemas de planificacion inversa

    Energy Technology Data Exchange (ETDEWEB)

    Perez Moreno, J. M.; Zucca Aparicio, D.; Fernandez leton, P.; Garcia Ruiz-Zorrilla, J.; Minambres Moro, A.

    2011-07-01

    One of the most important issues of intensity modulated radiation therapy (IMRT) treatments using the step-and-shoot technique is the number of segments and monitor units (MU) for treatment delivery. These parameters depend heavily on the inverse optimization module of the treatment planning system (TPS) used. Three commercial treatment planning systems: CMS XiO, iPlan and Prowess Panther have been evaluated. With each of them we have generated a treatment plan for the same group of patients, corresponding to clinical cases. Dosimetric results, MU calculated and number of segments were compared. Prowess treatment planning system generates plans with a number of segments significantly lower than other systems, while MU are less than a half. It implies important reductions in leakage radiation and delivery time. Degradation in the final dose calculation of dose is very small, because it directly optimizes positions of multileaf collimator (MLC). (Author) 13 refs.

  9. System engineering approach to planning anticancer therapies

    CERN Document Server

    Świerniak, Andrzej; Smieja, Jaroslaw; Puszynski, Krzysztof; Psiuk-Maksymowicz, Krzysztof

    2016-01-01

    This book focuses on the analysis of cancer dynamics and the mathematically based synthesis of anticancer therapy. It summarizes the current state-of-the-art in this field and clarifies common misconceptions about mathematical modeling in cancer. Additionally, it encourages closer cooperation between engineers, physicians and mathematicians by showing the clear benefits of this without stating unrealistic goals. Development of therapy protocols is realized from an engineering point of view, such as the search for a solution to a specific control-optimization problem. Since in the case of cancer patients, consecutive measurements providing information about the current state of the disease are not available, the control laws are derived for an open loop structure. Different forms of therapy are incorporated into the models, from chemotherapy and antiangiogenic therapy to immunotherapy and gene therapy, but the class of models introduced is broad enough to incorporate other forms of therapy as well. The book be...

  10. Behaviour therapy for obesity treatment considering approved drug therapy

    OpenAIRE

    Wasem, Jürgen; Ulle, Tanja; Kahl, Kai G; Kossmann, Beate; Aidelsburger, Pamela

    2008-01-01

    Introduction: Obesity is a worldwide health problem whose prevalence is on the increase. Many obesity-associated diseases require intensive medical treatment and are the cause of a large proportion of health-related expenditures in Germany. Treatment of obesity includes nutritional, exercise and behaviour therapy, usually in combination. The goal of behaviour therapy for obesity is to bring about a long-term alteration in the eating and exercise habits of overweight and obese individuals. Und...

  11. MO-C-BRF-01: Pediatric Treatment Planning I: Overview of Planning Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Olch, A [Childrens Hospital of LA, Los Angeles, CA (United States); Hua, C [St. Jude Childrens Research Hospital, Memphis, TN (United States)

    2014-06-15

    Most Medical Physicists working in radiotherapy departments see few pediatric patients. This is because, fortunately, children get cancer at a rate nearly 100 times lower than adults. Children have not smoked, abused alcohol, or been exposed to environmental carcinogens for decades, and of course, have not fallen victim to the aging process. Children get very different cancers than adults. Breast or prostate cancers, typical in adults, are rarely seen in children but instead a variety of tumors occur in children that are rarely seen in adults; examples are germinomas, ependymomas and primitive neuroectodermal tumors, which require treatment of the child's brain or neuroblastoma, requiring treatment in the abdomen. The treatment of children with cancer using radiation therapy is one of the most challenging planning and delivery problems facing the physicist. This is because bones, brain, breast tissue, and other organs are more sensitive to radiation in children than in adults. Because most therapy departments treat mostly adults, when the rare 8 year-old patient comes to the department for treatment, the physicist may not understand the clinical issues of his disease which drive the planning and delivery decisions. Additionally, children are more prone than adults to developing secondary cancers after radiation. This fact has important implications for the choice of delivery techniques, especially when considering IMRT. For bilateral retinoblastoma for example, an irradiated child has a 50% chance of developing a second cancer by age 50. In the first presentation, an overview of childhood cancers and their corresponding treatment techniques will be given. These can be some of the most complex treatments that are delivered in the radiation therapy department. These cancers include leukemia treated with total body irradiation, medulloblastoma, treated with craniospinal irradiation plus a conformal boost to the posterior fossa, neuroblastoma, requiring focal

  12. Quantifying the Effect of 3T Magnetic Resonance Imaging Residual System Distortions and Patient-Induced Susceptibility Distortions on Radiation Therapy Treatment Planning for Prostate Cancer.

    Science.gov (United States)

    Adjeiwaah, Mary; Bylund, Mikael; Lundman, Josef A; Karlsson, Camilla Thellenberg; Jonsson, Joakim H; Nyholm, Tufve

    2017-10-20

    To investigate the effect of magnetic resonance system- and patient-induced susceptibility distortions from a 3T scanner on dose distributions for prostate cancers. Combined displacement fields from the residual system and patient-induced susceptibility distortions were used to distort 17 prostate patient CT images. VMAT dose plans were initially optimized on distorted CT images and the plan parameters transferred to the original patient CT images to calculate a new dose distribution. Maximum residual mean distortions of 3.19 mm at a radial distance of 25 cm and maximum mean patient-induced susceptibility shifts of 5.8 mm were found using the lowest bandwidth of 122 Hz per pixel. There was a dose difference of resonance scanners are larger than residual system distortions after using vendor-supplied 3-dimensional correction for the delineated regions studied. However, errors in dose due to disturbed patient outline and shifts caused by patient-induced susceptibility effects are below 0.5%. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  13. SU-E-T-309: Dosimetric Comparison of Simultaneous Integrated Boost Treatment Plan Between Intensity Modulated Radiotherapies (IMRTs), Dual Arc Volumetric Modulated Arc Therapy (DA-VMAT) and Single Arc Volumetric Modulated Arc Therapy (SA-VMAT) for Nasopharyngeal Carcinoma (NPC)

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar, R; Janardhan, N; Bhavani, P; Surendran, J; Saranganathan, B; Ibrahim, S; Jhonson, B; Madhuri, B [Omega Hospitals, Hyderabad, Telangana (India); Anuradha, C [Vit University, Vellore, Tamil Nadu (India)

    2015-06-15

    Purpose: To compare the plan quality and performance of Simultaneous Integrated Boost (SIB) Treatment plan between Seven field (7F) and Nine field(9F) Intensity Modulated Radiotherapies and Single Arc (SA) and Dual Arc (DA) Volumetric Modulated Arc Therapy( VMAT). Methods: Retrospective planning study of 16 patients treated in Elekta Synergy Platform (mlci2) by 9F-IMRT were replanned with 7F-IMRT, Single Arc VMAT and Dual Arc VMAT using CMS, Monaco Treatment Planning System (TPS) with Monte Carlo simulation. Target delineation done as per Radiation Therapy Oncology Protocols (RTOG 0225&0615). Dose Prescribed as 70Gy to Planning Target Volumes (PTV70) and 61Gy to PTV61 in 33 fraction as a SIB technique. Conformity Index(CI), Homogeneity Index(HI) were used as analysis parameter for Target Volumes as well as Mean dose and Max dose for Organ at Risk(OAR,s).Treatment Delivery Time(min), Monitor unit per fraction (MU/fraction), Patient specific quality assurance were also analysed. Results: A Poor dose coverage and Conformity index (CI) was observed in PTV70 by 7F-IMRT among other techniques. SA-VMAT achieved poor dose coverage in PTV61. No statistical significance difference observed in OAR,s except Spinal cord (P= 0.03) and Right optic nerve (P=0.03). DA-VMAT achieved superior target coverage, higher CI (P =0.02) and Better HI (P=0.03) for PTV70 other techniques (7F-IMRT/9F-IMRT/SA-VMAT). A better dose spare for Parotid glands and spinal cord were seen in DA-VMAT. The average treatment delivery time were 5.82mins, 6.72mins, 3.24mins, 4.3mins for 7F-IMRT, 9F-IMRT, SA-VMAT and DA-VMAT respectively. Significance difference Observed in MU/fr (P <0.001) and Patient quality assurance pass rate were >95% (Gamma analysis (Γ3mm, 3%). Conclusion: DA-VAMT showed better target dose coverage and achieved better or equal performance in sparing OARs among other techniques. SA-VMAT offered least Treatment Time than other techniques but achieved poor target coverage. DA-VMAT offered

  14. Quantitative bioimaging of p-boronophenylalanine in thin liver tissue sections as a tool for treatment planning in boron neutron capture therapy.

    Science.gov (United States)

    Reifschneider, Olga; Schütz, Christian L; Brochhausen, Christoph; Hampel, Gabriele; Ross, Tobias; Sperling, Michael; Karst, Uwe

    2015-03-01

    An analytical method using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was developed and applied to assess enrichment of 10B-containing p-boronophenylalanine-fructose (BPA-f) and its pharmacokinetic distribution in human tissues after application for boron neutron capture therapy (BNCT). High spatial resolution (50 μm) and limits of detection in the low parts-per-billion range were achieved using a Nd:YAG laser of 213 nm wavelength. External calibration by means of 10B-enriched standards based on whole blood proved to yield precise quantification results. Using this calibration method, quantification of 10B in cancerous and healthy tissue was carried out. Additionally, the distribution of 11B was investigated, providing 10B enrichment in the investigated tissues. Quantitative imaging of 10B by means of LA-ICP-MS was demonstrated as a new option to characterise the efficacy of boron compounds for BNCT.

  15. Focal therapy for prostate cancer. Alternative treatment.

    Science.gov (United States)

    Gómez-Veiga, F; Martínez-Breijo, S; Solsona-Narbón, E; Hernández, C; Ciudin, A; Ribal, M J; Dickinson, L; Moore, C; Ahmed, H; Rodríguez Antolín, A; Breda, A; Gaya, J; Portela-Pereira, P; Emberton, M

    2014-09-01

    The great controversy surrounding the treatment of localized prostate cancer is related with its possibilities of radical treatment or active surveillance. The objective of this paper is to analyze the rationale selection among current focal therapy modalities regarding tumor and patient selection. Current articles about advantages and disadvantages on the treatment of localized prostate cancer as well as information about focal therapy regarding tumour selection, characteristics and indications cited in MEDLINE search were reviewed. Focal therapy standardized criteria must be: low risk tumors, PSA15. Focal therapy is an alternative for localized prostate cancer treatment. However, some aspects of their diagnosis and selection criteria should be defined by prospective studies which should provide knowledge about the indication for focal therapy. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

  16. Tolerance doses for treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Lyman, J.T.

    1985-10-01

    Data for the tolerance of normal tissues or organs to (low-LET) radiation has been compiled from a number of sources which are referenced at the end of this document. This tolerance dose data are ostensibly for uniform irradiation of all or part of an organ, and are for either 5% (TD/sub 5/) or 50% (TD/sub 50/) complication probability. The ''size'' of the irradiated organ is variously stated in terms of the absolute volume or the fraction of the organ volume irradiated, or the area or the length of the treatment field. The accuracy of these data is questionable. Much of the data represents doses that one or several experienced therapists have estimated could be safely given rather than quantitative analyses of clinical observations. Because these data have been obtained from multiple sources with possible different criteria for the definition of a complication, there are sometimes different values for what is apparently the same endpoint. The data from some sources shows a tendancy to be quantized in 5 Gy increments. This reflects the size of possible round off errors. It is believed that all these data have been accumulated without the benefit of 3-D dose distributions and therefore the estimates of the size of the volume and/or the uniformity of the irradiation may be less accurate than is now possible. 19 refs., 4 figs.

  17. A study of planning dose constraints for treatment of nasopharyngeal carcinoma using a commercial inverse treatment planning system.

    Science.gov (United States)

    Xia, Ping; Lee, Nancy; Liu, Yu-Ming; Poon, Ian; Weinberg, Vivian; Shin, Edward; Quivey, Jeanne M; Verhey, Lynn J

    2004-07-01

    The purpose of this study was to develop and test planning dose constraint templates for tumor and normal structures in the treatment of nasopharyngeal carcinoma (NPC) using a specific commercial inverse treatment planning system. Planning dose constraint templates were developed based on the analyses of dose-volume histograms (DVHs) of tumor targets and adjacent sensitive structures by clinically approved treatment plans of 9 T1-2 and 16 T3-4 NPC patients treated with inverse planned intensity-modulated radiation therapy (IP-IMRT). DVHs of sensitive structures were analyzed by examining multiple defined endpoints, based on the characteristics of each sensitive structure. For each subgroup of patients with T1-2 and T3-4 NPC, the resulting mean values of these defined endpoint doses were considered as templates for planning dose constraints and subsequently applied to a second group of patients, 5 with T1-2 NPC and 5 with T3-4 NPC. The 10 regenerated plans (called new plans) were compared to the original clinical plans that were used to treat the second group of patients, based on plan conformity index and DVHs. The conformity indices of the new plans were comparable to the original plans with no statistical difference (p = 0.85). Among the serial sensitive structures evaluated, there was a significant decrease with the new plans in the dose to the spinal cord when analyzed by the maximum dose (p = 0.001), doses encompassing 1 cc of the spinal cord volume (p = 0.001) and 3 cc of the spinal cord volume (p = 0.001). There was no significant difference in the mean maximum dose to the brainstem between the new plans and the original plans (p = 0.36). However, a significant difference in the mean maximum dose to the brainstem was seen among the different T-stages (p = 0.04). A decrease with the new plan to the brainstem in the doses encompassing 5% and 10% of the volume was of borderline statistical significance (p = 0.08 and p = 0.06, respectively). There were no

  18. Effectiveness of hypnosis therapy and Gestalt therapy as depression treatments

    Directory of Open Access Journals (Sweden)

    Elizabeth González-Ramírez

    2017-03-01

    Full Text Available We analyzed the effectiveness of two psychological therapies to treat depression in the Culiacan population, Mexico. According to criteria of MINI (international Neuropsychiatric interview, 30 individuals from a total of 300 were selected and diagnosed with some kind of depression. Patients were divided in three groups: 1 treatment with hypnosis therapy, 2 treatment with Gestalt-hypnosis therapy, and 3 control group. Before and after the treatments the Beck Anxiety Inventory (BAI was applied to know the depression level of the analyzed groups. The results show that the three groups were presenting a moderated level of depression. The groups under hypnosis therapy and Gestalt-hypnosis therapy show statistical differences between pre-test and post-test. The hypnosis therapy shows significant statistic differences to treat depression with respect to the other two groups. In conclusion, the therapeutic hypnosis is an effective treatment and has relevance to treat depression, while other therapeutic treatments tend to be slow and with minor result. This study is the first of this kind carried out in Culiacan in Sinaloa, Mexico.

  19. Development and clinical introduction of automated radiotherapy treatment planning for prostate cancer

    Science.gov (United States)

    Winkel, D.; Bol, G. H.; van Asselen, B.; Hes, J.; Scholten, V.; Kerkmeijer, L. G. W.; Raaymakers, B. W.

    2016-12-01

    To develop an automated radiotherapy treatment planning and optimization workflow to efficiently create patient specifically optimized clinical grade treatment plans for prostate cancer and to implement it in clinical practice. A two-phased planning and optimization workflow was developed to automatically generate 77Gy 5-field simultaneously integrated boost intensity modulated radiation therapy (SIB-IMRT) plans for prostate cancer treatment. A retrospective planning study (n  =  100) was performed in which automatically and manually generated treatment plans were compared. A clinical pilot (n  =  21) was performed to investigate the usability of our method. Operator time for the planning process was reduced to  <5 min. The retrospective planning study showed that 98 plans met all clinical constraints. Significant improvements were made in the volume receiving 72Gy (V72Gy) for the bladder and rectum and the mean dose of the bladder and the body. A reduced plan variance was observed. During the clinical pilot 20 automatically generated plans met all constraints and 17 plans were selected for treatment. The automated radiotherapy treatment planning and optimization workflow is capable of efficiently generating patient specifically optimized and improved clinical grade plans. It has now been adopted as the current standard workflow in our clinic to generate treatment plans for prostate cancer.

  20. Automation of radiation treatment planning : Evaluation of head and neck cancer patient plans created by the Pinnacle3scripting and Auto-Planning functions.

    Science.gov (United States)

    Speer, Stefan; Klein, Andreas; Kober, Lukas; Weiss, Alexander; Yohannes, Indra; Bert, Christoph

    2017-08-01

    Intensity-modulated radiotherapy (IMRT) techniques are now standard practice. IMRT or volumetric-modulated arc therapy (VMAT) allow treatment of the tumor while simultaneously sparing organs at risk. Nevertheless, treatment plan quality still depends on the physicist's individual skills, experiences, and personal preferences. It would therefore be advantageous to automate the planning process. This possibility is offered by the Pinnacle 3 treatment planning system (Philips Healthcare, Hamburg, Germany) via its scripting language or Auto-Planning (AP) module. AP module results were compared to in-house scripts and manually optimized treatment plans for standard head and neck cancer plans. Multiple treatment parameters were scored to judge plan quality (100 points = optimum plan). Patients were initially planned manually by different physicists and re-planned using scripts or AP. Script-based head and neck plans achieved a mean of 67.0 points and were, on average, superior to manually created (59.1 points) and AP plans (62.3 points). Moreover, they are characterized by reproducibility and lower standard deviation of treatment parameters. Even less experienced staff are able to create at least a good starting point for further optimization in a short time. However, for particular plans, experienced planners perform even better than scripts or AP. Experienced-user input is needed when setting up scripts or AP templates for the first time. Moreover, some minor drawbacks exist, such as the increase of monitor units (+35.5% for scripted plans). On average, automatically created plans are superior to manually created treatment plans. For particular plans, experienced physicists were able to perform better than scripts or AP; thus, the benefit is greatest when time is short or staff inexperienced.

  1. Monte Carlo calculations supporting patient plan verification in proton therapy

    Directory of Open Access Journals (Sweden)

    Thiago Viana Miranda Lima

    2016-03-01

    Full Text Available Patient’s treatment plan verification covers substantial amount of the quality assurance (QA resources, this is especially true for Intensity Modulated Proton Therapy (IMPT. The use of Monte Carlo (MC simulations in supporting QA has been widely discussed and several methods have been proposed. In this paper we studied an alternative approach from the one being currently applied clinically at Centro Nazionale di Adroterapia Oncologica (CNAO. We reanalysed the previously published data (Molinelli et al. 2013, where 9 patient plans were investigated in which the warning QA threshold of 3% mean dose deviation was crossed. The possibility that these differences between measurement and calculated dose were related to dose modelling (Treatment Planning Systems (TPS vs MC, limitations on dose delivery system or detectors mispositioning was originally explored but other factors such as the geometric description of the detectors were not ruled out. For the purpose of this work we compared ionisation-chambers measurements with different MC simulations results. It was also studied some physical effects introduced by this new approach for example inter detector interference and the delta ray thresholds. The simulations accounting for a detailed geometry typically are superior (statistical difference - p-value around 0.01 to most of the MC simulations used at CNAO (only inferior to the shift approach used. No real improvement were observed in reducing the current delta-ray threshold used (100 keV and no significant interference between ion chambers in the phantom were detected (p-value 0.81. In conclusion, it was observed that the detailed geometrical description improves the agreement between measurement and MC calculations in some cases. But in other cases position uncertainty represents the dominant uncertainty. The inter chamber disturbance was not detected for the therapeutic protons energies and the results from the current delta threshold are

  2. MO-D-BRB-01: Pediatric Treatment Planning I: Overview of Planning Strategies and Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Olch, A. [Childrens Hospital of LA (United States)

    2015-06-15

    Most Medical Physicists working in radiotherapy departments see few pediatric patients. This is because, fortunately, children get cancer at a rate nearly 100 times lower than adults. Children have not smoked, abused alcohol, or been exposed to environmental carcinogens for decades, and of course, have not fallen victim to the aging process. Children get very different cancers than adults. Breast or prostate cancers, typical in adults, are rarely seen in children but instead a variety of tumors occur in children that are rarely seen in adults; examples are germinomas, ependymomas and primitive neuroectodermal tumors, which require treatment of the child’s brain or neuroblastoma, requiring treatment in the abdomen. The treatment of children with cancer using radiation therapy is one of the most challenging planning and delivery problems facing the physicist. This is because bones, brain, breast tissue, and other organs are more sensitive to radiation in children than in adults. Because most therapy departments treat mostly adults, when the rare 8 year-old patient comes to the department for treatment, the physicist may not understand the clinical issues of his disease which drive the planning and delivery decisions. Additionally, children are more prone than adults to developing secondary cancers after radiation. For bilateral retinoblastoma for example, an irradiated child has a 40% chance of developing a second cancer by age 50. The dosimetric tradeoffs made during the planning process are complex and require careful consideration for children treated with radiotherapy. In the first presentation, an overview of childhood cancers and their corresponding treatment techniques will be given. These can be some of the most complex treatments that are delivered in the radiation therapy department. These cancers include leukemia treated with total body irradiation, medulloblastoma, treated with craniospinal irradiation plus a conformal boost to the posterior fossa

  3. Adaptive planning using megavoltage fan-beam CT for radiation therapy with testicular shielding

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Poonam [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); School of Advance Sciences, Vellore Institue of Technology University, Vellore, Tamil Nadu (India); Kozak, Kevin [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Tolakanahalli, Ranjini [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); Ramasubramanian, V. [School of Advance Sciences, Vellore Institue of Technology University, Vellore, Tamil Nadu (India); Paliwal, Bhudatt R. [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); University of Wisconsin, Riverview Cancer Centre, Wisconsin Rapids, WI (United States); Welsh, James S. [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); Rong, Yi, E-mail: rong@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); University of Wisconsin, Riverview Cancer Centre, Wisconsin Rapids, WI (United States)

    2012-07-01

    This study highlights the use of adaptive planning to accommodate testicular shielding in helical tomotherapy for malignancies of the proximal thigh. Two cases of young men with large soft tissue sarcomas of the proximal thigh are presented. After multidisciplinary evaluation, preoperative radiation therapy was recommended. Both patients were referred for sperm banking and lead shields were used to minimize testicular dose during radiation therapy. To minimize imaging artifacts, kilovoltage CT (kVCT) treatment planning was conducted without shielding. Generous hypothetical contours were generated on each 'planning scan' to estimate the location of the lead shield and generate a directionally blocked helical tomotherapy plan. To ensure the accuracy of each plan, megavoltage fan-beam CT (MVCT) scans were obtained at the first treatment and adaptive planning was performed to account for lead shield placement. Two important regions of interest in these cases were femurs and femoral heads. During adaptive planning for the first patient, it was observed that the virtual lead shield contour on kVCT planning images was significantly larger than the actual lead shield used for treatment. However, for the second patient, it was noted that the size of the virtual lead shield contoured on the kVCT image was significantly smaller than the actual shield size. Thus, new adaptive plans based on MVCT images were generated and used for treatment. The planning target volume was underdosed up to 2% and had higher maximum doses without adaptive planning. In conclusion, the treatment of the upper thigh, particularly in young men, presents several clinical challenges, including preservation of gonadal function. In such circumstances, adaptive planning using MVCT can ensure accurate dose delivery even in the presence of high-density testicular shields.

  4. Planning, optimisation and evaluation of hyperthermia treatments.

    Science.gov (United States)

    Kok, H P; Kotte, A N T J; Crezee, J

    2017-09-01

    Hyperthermia treatment planning using dedicated simulations of power and temperature distributions is very useful to assist in hyperthermia applications. This paper describes an advanced treatment planning software package for a wide variety of applications. The in-house developed C++ software package Plan2Heat runs on a Linux operating system. Modules are available to perform electric field and temperature calculations for many heating techniques. The package also contains optimisation routines, post-treatment evaluation tools and a sophisticated thermal model enabling to account for 3D vasculature based on an angiogram or generated artificially using a vessel generation algorithm. The use of the software is illustrated by a simulation of a locoregional hyperthermia treatment for a pancreatic cancer patient and a spherical tumour model heated by interstitial hyperthermia, with detailed 3D vasculature included. The module-based set-up makes the software flexible and easy to use. The first example demonstrates that treatment planning can help to focus the heating to the tumour. After optimisation, the simulated absorbed power in the tumour increased with 50%. The second example demonstrates the impact of accurately modelling discrete vasculature. Blood at body core temperature entering the heated volume causes relatively cold tracks in the heated volume, where the temperature remains below 40 °C. A flexible software package for hyperthermia treatment planning has been developed, which can be very useful in many hyperthermia applications. The object-oriented structure of the source code allows relatively easy extension of the software package with additional tools when necessary for future applications.

  5. Radiotherapy treatment planning linear-quadratic radiobiology

    CERN Document Server

    Chapman, J Donald

    2015-01-01

    Understand Quantitative Radiobiology from a Radiation Biophysics PerspectiveIn the field of radiobiology, the linear-quadratic (LQ) equation has become the standard for defining radiation-induced cell killing. Radiotherapy Treatment Planning: Linear-Quadratic Radiobiology describes tumor cell inactivation from a radiation physics perspective and offers appropriate LQ parameters for modeling tumor and normal tissue responses.Explore the Latest Cell Killing Numbers for Defining Iso-Effective Cancer TreatmentsThe book compil

  6. Proton Therapy Research and Treatment Center

    Energy Technology Data Exchange (ETDEWEB)

    Goodnight, J.E. Jr. (University of California Davis Medical Center, Sacramento, CA (United States). Cancer Center); Alonso, J.R. (Lawrence Berkeley Lab., CA (United States))

    1992-05-01

    This Grant proposal outlines the steps that will be undertaken to bring the UC Davis Proton Therapy Research and Treatment, known locally as the Proton Therapy Facility (PTF), through its design and construction phases. This application concentrates on the design phase of the PTF project.

  7. Ear Infection Treatment: Do Alternative Therapies Work?

    Science.gov (United States)

    ... t monitored and are subject to limited regulatory oversight by the Food and Drug Administration. Chiropractic treatment. ... costs. Alternative therapies may not be covered by medical insurance. Assess the credentials of anyone who advocates ...

  8. SU-E-T-570: Improvement to the Histogram Analysis in Radiation Therapy (HART): An Open Source Software System for the Multi-Dimensional Dose- Volume Histogram Analysis in Digital Image Communication in Medicine - Radiation Therapy (DICOM-RT) Treatment Plans.

    Science.gov (United States)

    Pyakuryal, A; Bacchus, I; Jang, S; Narayanasamy, G; Gopalakrishnan, M; Pokhrel, D; Luo, J; Sathiaseelan, V; Mittal, B

    2012-06-01

    Histogram Analysis in Radiation Therapy (HART) is an efficient and accurate dose-volume histogram (DVH) computational tool in radiotherapy research. Several applications of the program have been presented previously (J Appl Clin Med Phys 11(1): 3013, 2010; Med Phys 38(6), p.3678, 2011) for the Radiation Therapy Oncology Group (RTOG) users. The program has been further developed to incorporate various types of DVH analysis features to support the research using DICOM-RT plans. The main objective of this work was to present the improvement and compatibility of the program for the DICOM-RT plans. MATLAB based codes were primarily designed to read and write a simpler HART format from the standard DICOM-RT data objects exported from the Xio treatment planning system (CMS Inc., St. Louis, MO). This format employed an optimal polynomial fitting technique to interpolate the co-ordinates of the contours in the regions-of-interest. The format was efficient for the (a) precise extraction of the cumulative DVH (cDVH) and spatial DVH (sDVH; x-,y-, and z-DVHs respectively) data- statistics, (b) universal-plan indices evaluation, (c) biological modeling based outcome analyses (BMOA), (d) radiobiological dose-response modeling, and (e) physical parameterization modules. The fundamental DVH statistics were validated using the DVH statistics extracted from the Computational Environment for Radiotherapy Research program. HART offers various types of DVH computational functionalities, several plan evaluation and radiobiological outcome analysis modules in a user- friendly software package for the RTOG and DICOM-RT planners. The cDVH and BMOA modules were found to be the most applicable features for the global researchers. HART is a novel and universal multi-dimensional DVH analysis tool for the radiation therapy research. We further expect to develop HART for the space-time DVH analysis and proton therapy applications. The software is available online (http://www2.uic.edu/∼apyaku1

  9. Automated radiotherapy treatment plan integrity verification

    Energy Technology Data Exchange (ETDEWEB)

    Yang Deshan; Moore, Kevin L. [Department of Radiation Oncology, School of Medicine, Washington University in Saint Louis, St. Louis, Missouri 63110 (United States)

    2012-03-15

    Purpose: In our clinic, physicists spend from 15 to 60 min to verify the physical and dosimetric integrity of radiotherapy plans before presentation to radiation oncology physicians for approval. The purpose of this study was to design and implement a framework to automate as many elements of this quality control (QC) step as possible. Methods: A comprehensive computer application was developed to carry out a majority of these verification tasks in the Philips PINNACLE treatment planning system (TPS). This QC tool functions based on both PINNACLE scripting elements and PERL sub-routines. The core of this technique is the method of dynamic scripting, which involves a PERL programming module that is flexible and powerful for treatment plan data handling. Run-time plan data are collected, saved into temporary files, and analyzed against standard values and predefined logical rules. The results were summarized in a hypertext markup language (HTML) report that is displayed to the user. Results: This tool has been in clinical use for over a year. The occurrence frequency of technical problems, which would cause delays and suboptimal plans, has been reduced since clinical implementation. Conclusions: In addition to drastically reducing the set of human-driven logical comparisons, this QC tool also accomplished some tasks that are otherwise either quite laborious or impractical for humans to verify, e.g., identifying conflicts amongst IMRT optimization objectives.

  10. Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs

    Science.gov (United States)

    Li, Nan; Zarepisheh, Masoud; Uribe-Sanchez, Andres; Moore, Kevin; Tian, Zhen; Zhen, Xin; Jiang Graves, Yan; Gautier, Quentin; Mell, Loren; Zhou, Linghong; Jia, Xun; Jiang, Steve

    2013-12-01

    Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose-volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30 s using

  11. Cost-Effective Fuel Treatment Planning

    Science.gov (United States)

    Kreitler, J.; Thompson, M.; Vaillant, N.

    2014-12-01

    The cost of fighting large wildland fires in the western United States has grown dramatically over the past decade. This trend will likely continue with growth of the WUI into fire prone ecosystems, dangerous fuel conditions from decades of fire suppression, and a potentially increasing effect from prolonged drought and climate change. Fuel treatments are often considered the primary pre-fire mechanism to reduce the exposure of values at risk to wildland fire, and a growing suite of fire models and tools are employed to prioritize where treatments could mitigate wildland fire damages. Assessments using the likelihood and consequence of fire are critical because funds are insufficient to reduce risk on all lands needing treatment, therefore prioritization is required to maximize the effectiveness of fuel treatment budgets. Cost-effectiveness, doing the most good per dollar, would seem to be an important fuel treatment metric, yet studies or plans that prioritize fuel treatments using costs or cost-effectiveness measures are absent from the literature. Therefore, to explore the effect of using costs in fuel treatment planning we test four prioritization algorithms designed to reduce risk in a case study examining fuel treatments on the Sisters Ranger District of central Oregon. For benefits we model sediment retention and standing biomass, and measure the effectiveness of each algorithm by comparing the differences among treatment and no treat alternative scenarios. Our objective is to maximize the averted loss of net benefits subject to a representative fuel treatment budget. We model costs across the study landscape using the My Fuel Treatment Planner software, tree list data, local mill prices, and GIS-measured site characteristics. We use fire simulations to generate burn probabilities, and estimate fire intensity as conditional flame length at each pixel. Two prioritization algorithms target treatments based on cost-effectiveness and show improvements over those

  12. Proton Therapy Facility Planning From a Clinical and Operational Model.

    Science.gov (United States)

    Das, Indra J; Moskvin, Vadim P; Zhao, Qingya; Cheng, Chee-Wai; Johnstone, Peter A

    2015-10-01

    This paper provides a model for planning a new proton therapy center based on clinical data, referral pattern, beam utilization and technical considerations. The patient-specific data for the depth of targets from skin in each beam angle were reviewed at our center providing megavoltage photon external beam and proton beam therapy respectively. Further, data on insurance providers, disease sites, treatment depths, snout size and the beam angle utilization from the patients treated at our proton facility were collected and analyzed for their utilization and their impact on the facility cost. The most common disease sites treated at our center are head and neck, brain, sarcoma and pediatric malignancies. From this analysis, it is shown that the tumor depth from skin surface has a bimodal distribution (peak at 12 and 26 cm) that has significant impact on the maximum proton energy, requiring the energy in the range of 130-230 MeV. The choice of beam angles also showed a distinct pattern: mainly at 90° and 270°; this indicates that the number of gantries may be minimized. Snout usage data showed that 70% of the patients are treated with 10 cm snouts. The cost of proton beam therapy depends largely on the type of machine, maximum beam energy and the choice of gantry versus fixed beam line. Our study indicates that for a 4-room center, only two gantry rooms could be needed at the present pattern of the patient cohorts, thus significantly reducing the initial capital cost. In the USA, 95% and 100% of patients can be treated with 200 and 230 MeV proton beam respectively. Use of multi-leaf collimators and pencil beam scanning may further reduce the operational cost of the facility. © The Author(s) 2014.

  13. Interactive Decision-Support Tool for Risk-Based Radiation Therapy Plan Comparison for Hodgkin Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Brodin, N. Patrik [Department of Radiation Oncology, Albert Einstein College of Medicine of Yeshiva University, New York, New York (United States); Maraldo, Maja V., E-mail: dra.maraldo@gmail.com [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Aznar, Marianne C. [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Niels Bohr Institute, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Vogelius, Ivan R. [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Petersen, Peter M. [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Hematology, Rigshospitalet, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Bentzen, Søren M. [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Human Oncology, University of Wisconsin Medical School, Madison, Wisconsin (United States); Specht, Lena [Department of Radiation Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Oncology, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark); Department of Hematology, Rigshospitalet, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark)

    2014-02-01

    Purpose: To present a novel tool that allows quantitative estimation and visualization of the risk of various relevant normal tissue endpoints to aid in treatment plan comparison and clinical decision making in radiation therapy (RT) planning for Hodgkin lymphoma (HL). Methods and Materials: A decision-support tool for risk-based, individualized treatment plan comparison is presented. The tool displays dose–response relationships, derived from published clinical data, for a number of relevant side effects and thereby provides direct visualization of the trade-off between these endpoints. The Quantitative Analyses of Normal Tissue Effects in the Clinic reports were applied, complemented with newer data where available. A “relevance score” was assigned to each data source, reflecting how relevant the input data are to current RT for HL. Results: The tool is applied to visualize the local steepness of dose–response curves to drive the reoptimization of a volumetric modulated arc therapy treatment plan for an HL patient with head-and-neck involvement. We also use this decision-support tool to visualize and quantitatively evaluate the trade-off between a 3-dimensional conformal RT plan and a volumetric modulated arc therapy plan for a patient with mediastinal HL. Conclusion: This multiple-endpoint decision-support tool provides quantitative risk estimates to supplement the clinical judgment of the radiation oncologist when comparing different RT options.

  14. Photon and proton therapy planning comparison for malignant glioma based on CT, FDG-PET, DTI-MRI and fiber tracking

    DEFF Research Database (Denmark)

    Munck af Rosenschöld, Per; Engelholm, Silke; Ohlhues, Lars

    2011-01-01

    The purpose of this study was to compare treatment plans generated using fixed beam Intensity Modulated photon Radiation Therapy (IMRT), inversely optimized arc therapy (RapidArc(R), RA) with spot-scanned Intensity Modulated Proton Therapy (IMPT) for high-grade glioma patients. Plans were compared...

  15. Photon and proton therapy planning comparison for malignant glioma based on CT, FDG-PET, DTI-MRI and fiber tracking

    DEFF Research Database (Denmark)

    Munck af Rosenschöld, Per; Engelholm, Silke; Ohlhues, Lars

    2011-01-01

    The purpose of this study was to compare treatment plans generated using fixed beam Intensity Modulated photon Radiation Therapy (IMRT), inversely optimized arc therapy (RapidArc(R), RA) with spot-scanned Intensity Modulated Proton Therapy (IMPT) for high-grade glioma patients. Plans were compare...

  16. Computerized System for Safety Verification of External Beam Radiation Therapy Planning.

    Science.gov (United States)

    Holdsworth, Clay; Kukluk, Jacek; Molodowitch, Christina; Czerminska, Maria; Hancox, Cindy; Cormack, Robert A; Beaudette, Kevin; Killoran, Joseph H

    2017-07-01

    To report an assessment of in-house software, Verifier, developed to improve efficacy and efficiency of the radiation therapy (RT) treatment planning process and quality control review (QCR). Radiation therapy plan parameters retrieved from our treatment planning database are used by automated tests to give 75 types of warnings, such as prescription and plan discrepancies. The software is continuously updated on the basis of new issues, ideas, and planning policies. Verifier was retrospectively assessed (2007-2015) by examining impact on treatment plan revisions, frequency of quality improvement incident reports of avoidable RT plan-related safety events, unaddressed issues, and staff efficiency. Plan revisions for specific issues declined dramatically in response to implementation of corresponding Verifier tests. Between 2012 and 2015 our institution's total rate of plan revisions dropped from 18.0% to 11.2%. Between 2008 and 2015 specific tests were added to Verifier while the rate of corresponding avoidable safety events was reduced from 0.34% to 0.00% over the same period. Simulations suggest Verifier saves approximately 2 to 5 minutes per QCR. The decrease in quantifiable metrics of plan revisions and incident reports suggests automatic RT plan-checking software enhances patient safety and clinical efficiency. Although only modest time savings may be gained using Verifier for the QCR itself, the greater impact on efficiency is through avoiding late-stage plan modifications and improving documentation via automation. We encourage other institutions to consider working toward adding similar technologies to enhance their RT quality assurance programs. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Conformal three dimensional radiotherapy treatment planning in Lund

    Energy Technology Data Exchange (ETDEWEB)

    Knoos, T.; Nilsson, P. [Lund Univ. (Sweden). Dept. of Radiation Physics; Anders, A. [Lund Univ. (Sweden). Dept. of Oncology

    1995-12-01

    The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam`s eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam`s eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment.

  18. AIDA: web agents in dental treatment planning.

    Science.gov (United States)

    Finkeissen, E; Stamm, I; Müssig, M; Streicher, J; Koke, U; Helmstetter, C; Hassfeld, S; Wetter, T

    2003-12-01

    The objective of the AIDA project (Artificial Intelligent Dental Agents, http://aida.uni-hd.de) is the analysis of dental decision-making, the design of a computer-based decision support system, as well as the testing of the decision structure in interactions with dental experts, practicing dentists, and patients. The planning of the solution alternatives for an individual patient is based on a top-down structure for dental decision-making, aiming at a standardization of the argumentation. From a theoretical point of view, decision support can be provided only for anticipated decisions (planning). Moreover, only parts of these anticipated decisions can be supported. Accordingly, a separation of these partial aspects has to take place before one is able to build decision support systems. For prosthetic dentistry, clinicians have been shown how to use individual patient findings to sketch the possible treatment alternatives and later derive guidelines for the treatment. The planning module for fixed prostheses has already been integrated into a software agent. Planning modules for other types of prostheses are currently specified, implemented, and verified.

  19. Ectopic pregnancy treatment by combination therapy

    OpenAIRE

    Cymbaluk-Płoska Aneta; Chudecka-Głaz Anita; Kuźniak Sławomir; Menkiszak Janusz

    2016-01-01

    Abstract Detectability of early stages of ectopic pregnancies has increased due to improvements in ultrasonographic and biochemical techniques. Since the patients? future procreative plans must be taken into consideration when commencing treatment, the goal of this work was to compare the effects of treatment methods and their impact on fertility. The study included 91 patients treated surgically for ectopic pregnancy. The choice of treatment depended on patients? general condition, ultrasono...

  20. The use of discrete-event simulation modelling to improve radiation therapy planning processes.

    Science.gov (United States)

    Werker, Greg; Sauré, Antoine; French, John; Shechter, Steven

    2009-07-01

    The planning portion of the radiation therapy treatment process at the British Columbia Cancer Agency is efficient but nevertheless contains room for improvement. The purpose of this study is to show how a discrete-event simulation (DES) model can be used to represent this complex process and to suggest improvements that may reduce the planning time and ultimately reduce overall waiting times. A simulation model of the radiation therapy (RT) planning process was constructed using the Arena simulation software, representing the complexities of the system. Several types of inputs feed into the model; these inputs come from historical data, a staff survey, and interviews with planners. The simulation model was validated against historical data and then used to test various scenarios to identify and quantify potential improvements to the RT planning process. Simulation modelling is an attractive tool for describing complex systems, and can be used to identify improvements to the processes involved. It is possible to use this technique in the area of radiation therapy planning with the intent of reducing process times and subsequent delays for patient treatment. In this particular system, reducing the variability and length of oncologist-related delays contributes most to improving the planning time.

  1. Treating Social Anxiety in Adolescents: Ten Group Therapy Lesson Plans

    Science.gov (United States)

    Mazur-Elmer, Alison; McBride, Dawn

    2009-01-01

    This project provides a comprehensive overview of the research literature on social anxiety disorder (SAD) in adolescents and concludes by offering a set of 10 group therapy lesson plans for SAD that therapists can use in their practice. The overview includes a description of social anxiety disorder and highlights various theories of anxiety. The…

  2. Conformal treatment planning for interstitial brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, G. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Hebbinghaus, D. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Dennert, P. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Kohr, P. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Wilhelm, R. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Kimmig, B. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie)

    1996-09-01

    Quality of a brachytherapy application depends on the choice of the target volume, on the dose distribution homogeneity and radiation injury on critical tissue, which should be postulated by advanced brachytherapy treatment planning systems. Basic imaging method for conformal treatment planning is the cross-sectional imaging. The clinical applicatibility of a new type 3D planning system using CT and/or MRT-simulation or US-simulation for planning purposes was studied. The planning system developed at Kiel University differs from usual brachytherapy planning systems because of the obligatory use of cross-sectional imaging as basic imaging method for reconstruction of structures of interest. Dose distribution and normal anatomy can be visualized on each CT/MRT/US slice as well as coronal, sagittal, axial and free chosen reconstructions (3D), as well as dose-volume histogram curves and special colour-coded visualization of dose homogeneity in the target can be analyzed. Because of the experience in the clinical routine, as well as on the base of 30 simultaneous planning procedures on both 2D (semi-3D) and 3D planning systems we observed similar time consumption. Advantages of 3D planning were the better interpretation of target delineation, delineation of critical structures as well as dose distribution, causing more accurate volume optimisation of dose distribution. Conformal brachytherapy treatment planning for interstitial brachytherapy means significant advantages for the clinical routine compared to 2D or semi-3D methods. (orig.) [Deutsch] Die Qualitaet einer Brachytherapieapplikation ist abhaengig von der Zielvolumenwahl, der homogenen Dosisverteilung und der Schonung kritischer Organe. Diese Voraussetzungen koennen am besten mit Hilfe eines 3D-Planungssystem erfuellt werden. Als Planungsvorlage fuer die Konformationstherapieplanung sind am besten Schnittbilder (CT, MRT, US) geeignet. Es wurde die Anwendbarkeit eines auf CT- (oder MRT-)Simulation oder geeignete

  3. Effects of spot parameters in pencil beam scanning treatment planning.

    Science.gov (United States)

    Kraan, Aafke Christine; Depauw, Nicolas; Clasie, Ben; Giunta, Marina; Madden, Tom; Kooy, Hanne M

    2017-11-17

    Spot size σ (in air at isocenter), interspot spacing d, and spot charge q influence dose delivery efficiency and plan quality in Intensity Modulated Proton Therapy (IMPT) treatment planning. The choice and range of parameters varies among different manufacturers. The goal of this work is to demonstrate the influence of the spot parameters on dose quality and delivery in IMPT treatment plans, to show their interdependence, and to make practitioners aware of the spot parameter values for a certain facility. Our study could help as a guideline to make the trade-off between treatment quality and time in existing PBS centers and in future systems. We created plans for seven patients and a phantom, with different tumor sites and volumes, and compared the effect of small-, medium-, and large-spot widths (σ = 2.5, 5, and 10 mm) and interspot distances (1σ, 1.5σ, and 1.75σ) on dose, spot charge, and treatment time. Moreover, we quantified how postplanning charge threshold cuts affect plan quality and the total number of spots to deliver, for different spot widths and interspot distances. We show the effect of a minimum charge (or MU) cutoff value for a given proton delivery system. Spot size had a strong influence on dose: larger spots resulted in more protons delivered outside the target region. We observed dose differences of 2-13 Gy (RBE) between 2.5 mm and 10 mm spots, where the amount of extra dose was due to dose penumbra around the target region. Interspot distance had little influence on dose quality for our patient group. Both parameters strongly influence spot charge in the plans and thus the possible impact of postplanning charge threshold cuts. If such charge thresholds are not included in the treatment planning system (TPS), it is important that the practitioner validates that a given combination of lower charge threshold, interspot spacing, and spot size does not result in a plan degradation. Low average spot charge occurs for small spots, small interspot

  4. Peripheral CT angiography for interventional treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmann, D. [Dept. of Radiology, Stanford Univ. Medical Center, Stanford, CA (United States); Lammer, J. [Dept. of Interventional Radiology, Medical Univ. of Vienna (Austria)

    2006-01-10

    Lower extremity CT angiography (CTA) has evolved into a very effective, widely available and robust imaging modality for patients with peripheral arterial occlusive disease (PAOD). In this article we briefly review the acquisition and contrast administration techniques for 4- through 64-channel peripheral CTA. Visualization of atherosclerotic disease with CTA in general requires 'angiography-like' 3D images (such as volume rendered or maximum intensity projection images), but-notably in the presence of vessel wall calcifications and stents-cross-sectional views (such as curved planar reformations, CPR) are also required to accurately assess the flow lumen of the aorta down to the pedal arteries. Adequate visualization and mapping of atherosclerotic lesions in patients with PAOD is not only a prerequisite for generating a dictated report, but more importantly, standardized postprocessed images are the key to communicating the findings to the treating physician, and they also serve as a treatment planning tool. Treatment decisions (surgical versus transluminal revascularization, or conservative treatment), and percutaneous treatment planning (access site, antegrade versus retrograde puncture) can be made in the majority of patients with PAOD based on lower extremity CT angiograms. (orig.)

  5. The imaging revolution and radiation oncology: use of CT, ultrasound, and NMR for localization, treatment planning and treatment delivery.

    Science.gov (United States)

    Glatstein, E; Lichter, A S; Fraass, B A; Kelly, B A; van de Geijn, J

    1985-02-01

    The explosion of new imaging technologies such as X ray computed tomography (CT), ultrasound (US), positron emission tomography (PET), and nuclear magnetic resonance imaging (NMR) has forced a major change in radiation therapy treatment planning philosophy and procedures. Modern computer technology has been wedded to these new imaging modalities, making possible sophisticated radiation therapy treatment planning using both the detailed anatomical and density information that is made available by CT and the other imaging modalities. This has forced a revolution in the way treatments are planned, with the result that actual beam configurations are typically both more complex and more carefully tailored to the desired target volume. This increase in precision and accuracy will presumably improve the results of radiation therapy.

  6. Photopneumatic therapy for the treatment of acne.

    Science.gov (United States)

    Wanitphakdeedecha, Rungsima; Tanzi, Elizabeth L; Alster, Tina S

    2009-03-01

    A wide variety of laser and light-based therapies have been utilized for acne vulgaris; however, current techniques have been limited by photosensitivity issues or inconsistent results. To determine the clinical efficacy and side-effect profile of photopneumatic therapy for the treatment of facial acne vulgaris. Twenty adults with mild to severe facial acne vulgaris received 4 successive treatments at 2-week intervals with a combined photopneumatic device (intense pulsed light [IPL]: fluences = 3.6-4.2 J/cm2; negative pressure = 3 psi). Clinical improvement was evaluated on a quartile grading scale using comparative digital photographs at baseline, and 1 month and 3 months after the final treatment. Acne lesion counts were obtained at baseline, prior to each treatment session, and at the end of the study. Modest reduction in acne lesion counts and global clinical improvement was seen in the majority of patients. Patients with severe acne experienced the most clinical improvement. Side effects were mild and limited to transient erythema and rare purpura. Most patients experienced acne worsening early in the treatment course. Photopneumatic therapy is a safe and effective treatment for acne vulgaris. Patients with more severe acne respond best to treatment.

  7. MO-D-BRB-02: Pediatric Treatment Planning II: Applications of Proton Beams for Pediatric Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hua, C. [St. Jude Childrens Research Hospital (United States)

    2015-06-15

    Most Medical Physicists working in radiotherapy departments see few pediatric patients. This is because, fortunately, children get cancer at a rate nearly 100 times lower than adults. Children have not smoked, abused alcohol, or been exposed to environmental carcinogens for decades, and of course, have not fallen victim to the aging process. Children get very different cancers than adults. Breast or prostate cancers, typical in adults, are rarely seen in children but instead a variety of tumors occur in children that are rarely seen in adults; examples are germinomas, ependymomas and primitive neuroectodermal tumors, which require treatment of the child’s brain or neuroblastoma, requiring treatment in the abdomen. The treatment of children with cancer using radiation therapy is one of the most challenging planning and delivery problems facing the physicist. This is because bones, brain, breast tissue, and other organs are more sensitive to radiation in children than in adults. Because most therapy departments treat mostly adults, when the rare 8 year-old patient comes to the department for treatment, the physicist may not understand the clinical issues of his disease which drive the planning and delivery decisions. Additionally, children are more prone than adults to developing secondary cancers after radiation. For bilateral retinoblastoma for example, an irradiated child has a 40% chance of developing a second cancer by age 50. The dosimetric tradeoffs made during the planning process are complex and require careful consideration for children treated with radiotherapy. In the first presentation, an overview of childhood cancers and their corresponding treatment techniques will be given. These can be some of the most complex treatments that are delivered in the radiation therapy department. These cancers include leukemia treated with total body irradiation, medulloblastoma, treated with craniospinal irradiation plus a conformal boost to the posterior fossa

  8. An FDTD code for hyperthermia treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Marrocco, G.; Bardati, F. [Rome Univ. Tor Vergata (Italy). Dipt. di Informatica, sistemi e produzione; Tognolatti, P. [L' Aquila Univ. (Italy). Dipt. di Ingegneria Elettrica

    1999-08-01

    Radio-frequency hyperthermia is an anticancer modality based on the heating of tumours by radiating sources. A set of antennas is frequently used to enhance power depositions in tissues. Treatments planning needs electromagnetic field computation within realistic body models. Since several simulation may be required the optimize the antenna-body configuration, the electromagnetic solver should be designed in such a way that new configuration of the antenna set-up can be solved without heavy changes of the basic numerical code. In this paper a numerical investigation on the effects of a segmentation technique will be presented, with reference to an FDTD computation and the heating of a paediatric tumour.

  9. Alopecia areata: a new treatment plan

    Science.gov (United States)

    Alsantali, Adel

    2011-01-01

    Many therapeutic modalities have been used to treat alopecia areata, with variable efficacy and safety profiles. Unfortunately, none of these agents is curative or preventive. Also, many of these therapeutic agents have not been subjected to randomized, controlled trials, and, except for topical immunotherapy, there are few published studies on long-term outcomes. The treatment plan is designed according to the patient’s age and extent of disease. In this paper, the therapeutic agents are organized according to their efficacy and safety profiles into first-line, second-line, and third-line options. PMID:21833161

  10. Simple Case Treatment Planning: Diastema Closure.

    Science.gov (United States)

    Calamia, Vincent; Pantzis, Alexandria

    2015-07-01

    This article demonstrates the use of a smile evaluation form as an adjunct in arriving at diagnosis and developing a treatment plan for a patient desiring Diastema closure. It also shows the importance of the diagnostic wax-up for temporization and visualization of case outcome. The case also demonstrates the use of soft tissue lasers to create a gingival harmony that enhanced the resulting esthetics. Feldspathic porcelain was used for the final restorations because they provide optimal esthetics and translucency. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Comparison among therapy planning in volumetric modulated arc for prostate treatments using one or two arches; Comparacao entre planejamentos de terapia em arco volumetrico modulado para tratamentos de prostata utilizando um ou dois arcos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Diego C.S.A.; Pavan, Guilherme A.; Nardi, Stela P.; Fairbanks, Leandro R.; Anderson, Ernani; Junior, Juraci P.R.; Junior, Helio A.S., E-mail: diegocunhalves@hotmail.com [Clinicas Oncologicas Integradas/Grupo COI, Rio de Janeiro, RJ (Brazil)

    2014-04-15

    The study aims to evaluate and compare retrospective planning for prostate cancer using the volumetric modulated arc therapy technique (RapidArc™ - Varian) with one or two arcs. Ten cases of patients with prostate cancer present were replanning with the volume of PTV's between 296.4 cm{sup 3} and 149.6 cm{sup 3} with prescribed dose of 78 Gy. A planning default was created for each case seeking the best result of the distribution dose in the PTV and to minimize the dose to organs at risk, and from this, creates two copies for optimization of one and two arcs. Comparisons of maximum and minimum dose, index of conformity, homogeneity and gradient dose were evaluated in the PTV, the time of the radiation beam and the number of monitor units. The organ at risk were evaluated according to the Radiation Therapy Oncology Group RTOG 0415 and compared in both optimizations. In terms of dosimetric values to organs at risk and PTV were similar, but there was an increase in the number of monitors units and the time of the radiation beam when using the technique with two arcs. Finally the results have showed that use a volumetric modulated arc therapy optimization for prostate cancer it is reaches similar dosimetric goals can be an effective option for radiotherapy department of developing countries with large number of patients. (author)

  12. Interdisciplinary treatment planning in inpatient settings: from myth to model.

    Science.gov (United States)

    McLoughlin, Kris A; Geller, Jeffrey L

    2010-09-01

    The staffs of many mental health facilities describe their treatment planning processes as interdisciplinary, but as most practicing clinicians know, this is more of a myth than reality. Individualized, person-focused treatment planning itself is not a simple endeavor. Effective treatment planning is further complicated by the fact that most discipline training programs teach neither treatment planning nor interdisciplinary methods to provide care and treatment. Psychiatric treatment teams are at a disadvantage from the start. Additionally, although facility and agency administrators expect treatment planning to occur, often the infrastructure to support the work is not there. This article describes a practical and effective treatment planning implementation model or framework developed by the authors, concentrating on three sub-sets of the treatment planning system: structure, content, and process.

  13. Treatment Failure in Dialectical Behavior Therapy

    Science.gov (United States)

    Rizvi, Shireen L.

    2011-01-01

    Dialectical behavior therapy (DBT) has become a widely used treatment model for individuals with borderline personality disorder (BPD) and other individuals with significant emotion dysregulation problems. Despite its strong empirical support, DBT obviously does not have positive outcomes for all individuals. It is critical that cases of DBT…

  14. Treatment for Chronic Depression Using Schema Therapy

    NARCIS (Netherlands)

    Renner, F.; Arntz, A.; Leeuw, I.; Huibers, M.J.H.

    2013-01-01

    Schema therapy (ST) is an integrative treatment approach to chronic lifelong problems with an established effectiveness for treating personality disorders. This article describes the adaptation of ST to chronic depression by reviewing the literature on the underlying risk factors to chronic

  15. A fast optimization algorithm for multicriteria intensity modulated proton therapy planning.

    Science.gov (United States)

    Chen, Wei; Craft, David; Madden, Thomas M; Zhang, Kewu; Kooy, Hanne M; Herman, Gabor T

    2010-09-01

    To describe a fast projection algorithm for optimizing intensity modulated proton therapy (IMPT) plans and to describe and demonstrate the use of this algorithm in multicriteria IMPT planning. The authors develop a projection-based solver for a class of convex optimization problems and apply it to IMPT treatment planning. The speed of the solver permits its use in multicriteria optimization, where several optimizations are performed which span the space of possible treatment plans. The authors describe a plan database generation procedure which is customized to the requirements of the solver. The optimality precision of the solver can be specified by the user. The authors apply the algorithm to three clinical cases: A pancreas case, an esophagus case, and a tumor along the rib cage case. Detailed analysis of the pancreas case shows that the algorithm is orders of magnitude faster than industry-standard general purpose algorithms (MOSEK'S interior point optimizer, primal simplex optimizer, and dual simplex optimizer). Additionally, the projection solver has almost no memory overhead. The speed and guaranteed accuracy of the algorithm make it suitable for use in multicriteria treatment planning, which requires the computation of several diverse treatment plans. Additionally, given the low memory overhead of the algorithm, the method can be extended to include multiple geometric instances and proton range possibilities, for robust optimization.

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

    Science.gov (United States)

    Jurkovic, Ines-Ana

    Stereotactic body radiation therapy is currently being used as an efficient treatment for Stage I/II medically inoperable and surgically unrespectable non small cell and metastatic lung cancer. Hypofractional dose and dose escalation used in stereotactic body radiation therapy have the potential of increasing the likelihood of the tumor control and the long term progression free survival. Currently available commercial treatment planning systems are capable of calculating accurate dose distributions for static case, where the tumor and surrounding healthy tissues are not moving during the dose delivery. However, respiratory induced organ motion can result in significant movement of the lesion leading to the discrepancies between the dose delivered and the dose planned. The precision and conformity of the stereotactic body radiation therapy makes it very susceptible to motion, i.e. patient respiration can lead to significant dose delivery errors. Conventional stereotactic body radiation therapy treatment plans use free breathing three-dimensional computed tomography images where margins are added to delineated gross tumor volume to create planning tumor volume and avoid geometrical misses of the target. The specific hypothesis of the study is that the true four-dimensional delivery of the four-dimensional plans will allow for more accurate radiation therapy treatment and critical organ sparing along with radiobiological evaluation of the dose distributions. The specific aims are designed to provide in depth understanding of the radiation therapy treatments and influence of the four-dimensional planning and delivery, heterogeneity corrections and various radiobiological factors on the outcome. The primary focus of the Specific Aim 1 was the evaluation of the tumor volume based on the four-dimensional computed tomography scan data through its motion, volume and computed tomography number. The results indicated that tumor motion parameters will exceed the typical

  17. Current concepts in F18 FDG PET/CT-based Radiation Therapy planning for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Percy eLee

    2012-07-01

    Full Text Available Radiation therapy is an important component of cancer therapy for early stage as well as locally advanced lung cancer. The use of F18 FDG PET/CT has come to the forefront of lung cancer staging and overall treatment decision-making. FDG PET/CT parameters such as standard uptake value and metabolic tumor volume provide important prognostic and predictive information in lung cancer. Importantly, FDG PET/CT for radiation planning has added biological information in defining the gross tumor volume as well as involved nodal disease. For example, accurate target delineation between tumor and atelectasis is facilitated by utilizing PET and CT imaging. Furthermore, there has been meaningful progress in incorporating metabolic information from FDG PET/CT imaging in radiation treatment planning strategies such as radiation dose escalation based on standard uptake value thresholds as well as using respiratory gated PET and CT planning for improved target delineation of moving targets. In addition, PET/CT based follow-up after radiation therapy has provided the possibility of early detection of local as well as distant recurrences after treatment. More research is needed to incorporate other biomarkers such as proliferative and hypoxia biomarkers in PET as well as integrating metabolic information in adaptive, patient-centered, tailored radiation therapy.

  18. Vaginismus treatment. Hypnotherapy versus behavior therapy.

    Science.gov (United States)

    Al-Sughayir, Mohammed A

    2005-04-01

    To investigate the effectiveness of hypnotherapy in the treatment of vaginismus compared to behavior therapy. A consecutive sample of 36 women with vaginismus (DSM-IV criteria) referred to the out-patient psychiatry clinic at King Abdul-Aziz University Hospital in Riyadh between 1999-2003 were divided into 2 groups for either treatment on a random basis. A female psychologist independently and carefully assessed patients before and after treatment. Patients were treated until they achieved satisfactory sexual intercourse. Although both behavior therapy and hypnotherapy were successful in treating vaginismus, hypnotherapy performed better than behavior therapy in reducing the level of the wife`s sex-related anxiety and in improving the husband`s sexual satisfaction score. Success tended to occur faster in women treated with hypnotherapy as they received fewer treatment sessions. Women with vaginismus can be successfully treated by hypnotherapy without simultaneous treatment of their husbands. Hypnotherapy can provide an acceptable time and cost effective therapeutic tool that helps resolve vaginismus and improves sexual satisfaction in both spouses.

  19. Metal artifacts in computed tomography for radiation therapy planning: dosimetric effects and impact of metal artifact reduction

    Science.gov (United States)

    Giantsoudi, Drosoula; De Man, Bruno; Verburg, Joost; Trofimov, Alexei; Jin, Yannan; Wang, Ge; Gjesteby, Lars; Paganetti, Harald

    2017-04-01

    A significant and increasing number of patients receiving radiation therapy present with metal objects close to, or even within, the treatment area, resulting in artifacts in computed tomography (CT) imaging, which is the most commonly used imaging method for treatment planning in radiation therapy. In the presence of metal implants, such as dental fillings in treatment of head-and-neck tumors, spinal stabilization implants in spinal or paraspinal treatment or hip replacements in prostate cancer treatments, the extreme photon absorption by the metal object leads to prominent image artifacts. Although current CT scanners include a series of correction steps for beam hardening, scattered radiation and noisy measurements, when metal implants exist within or close to the treatment area, these corrections do not suffice. CT metal artifacts affect negatively the treatment planning of radiation therapy either by causing difficulties to delineate the target volume or by reducing the dose calculation accuracy. Various metal artifact reduction (MAR) methods have been explored in terms of improvement of organ delineation and dose calculation in radiation therapy treatment planning, depending on the type of radiation treatment and location of the metal implant and treatment site. Including a brief description of the available CT MAR methods that have been applied in radiation therapy, this article attempts to provide a comprehensive review on the dosimetric effect of the presence of CT metal artifacts in treatment planning, as reported in the literature, and the potential improvement suggested by different MAR approaches. The impact of artifacts on the treatment planning and delivery accuracy is discussed in the context of different modalities, such as photon external beam, brachytherapy and particle therapy, as well as by type and location of metal implants.

  20. Metal artifacts in computed tomography for radiation therapy planning: dosimetric effects and impact of metal artifact reduction.

    Science.gov (United States)

    Giantsoudi, Drosoula; De Man, Bruno; Verburg, Joost; Trofimov, Alexei; Jin, Yannan; Wang, Ge; Gjesteby, Lars; Paganetti, Harald

    2017-04-21

    A significant and increasing number of patients receiving radiation therapy present with metal objects close to, or even within, the treatment area, resulting in artifacts in computed tomography (CT) imaging, which is the most commonly used imaging method for treatment planning in radiation therapy. In the presence of metal implants, such as dental fillings in treatment of head-and-neck tumors, spinal stabilization implants in spinal or paraspinal treatment or hip replacements in prostate cancer treatments, the extreme photon absorption by the metal object leads to prominent image artifacts. Although current CT scanners include a series of correction steps for beam hardening, scattered radiation and noisy measurements, when metal implants exist within or close to the treatment area, these corrections do not suffice. CT metal artifacts affect negatively the treatment planning of radiation therapy either by causing difficulties to delineate the target volume or by reducing the dose calculation accuracy. Various metal artifact reduction (MAR) methods have been explored in terms of improvement of organ delineation and dose calculation in radiation therapy treatment planning, depending on the type of radiation treatment and location of the metal implant and treatment site. Including a brief description of the available CT MAR methods that have been applied in radiation therapy, this article attempts to provide a comprehensive review on the dosimetric effect of the presence of CT metal artifacts in treatment planning, as reported in the literature, and the potential improvement suggested by different MAR approaches. The impact of artifacts on the treatment planning and delivery accuracy is discussed in the context of different modalities, such as photon external beam, brachytherapy and particle therapy, as well as by type and location of metal implants.

  1. Treatment planning for radiotherapy with very high-energy electron beams and comparison of VHEE and VMAT plans

    Energy Technology Data Exchange (ETDEWEB)

    Bazalova-Carter, Magdalena; Qu, Bradley; Palma, Bianey; Jensen, Christopher; Maxim, Peter G., E-mail: Peter.Maxim@Stanford.edu, E-mail: BWLoo@Stanford.edu; Loo, Billy W., E-mail: Peter.Maxim@Stanford.edu, E-mail: BWLoo@Stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Hårdemark, Björn; Hynning, Elin [RaySearch Laboratories AB, Stockholm SE-103 65 (Sweden)

    2015-05-15

    Purpose: The aim of this work was to develop a treatment planning workflow for rapid radiotherapy delivered with very high-energy electron (VHEE) scanning pencil beams of 60–120 MeV and to study VHEE plans as a function of VHEE treatment parameters. Additionally, VHEE plans were compared to clinical state-of-the-art volumetric modulated arc therapy (VMAT) photon plans for three cases. Methods: VHEE radiotherapy treatment planning was performed by linking EGSnrc Monte Carlo (MC) dose calculations with inverse treatment planning in a research version of RayStation. In order to study the effect of VHEE treatment parameters on VHEE dose distributions, a MATLAB graphical user interface (GUI) for calculation of VHEE MC pencil beam doses was developed. Through the GUI, pediatric case MC simulations were run for a number of beam energies (60, 80, 100, and 120 MeV), number of beams (13, 17, and 36), pencil beam spot (0.1, 1.0, and 3.0 mm) and grid (2.0, 2.5, and 3.5 mm) sizes, and source-to-axis distance, SAD (40 and 50 cm). VHEE plans for the pediatric case calculated with the different treatment parameters were optimized and compared. Furthermore, 100 MeV VHEE plans for the pediatric case, a lung, and a prostate case were calculated and compared to the clinically delivered VMAT plans. All plans were normalized such that the 100% isodose line covered 95% of the target volume. Results: VHEE beam energy had the largest effect on the quality of dose distributions of the pediatric case. For the same target dose, the mean doses to organs at risk (OARs) decreased by 5%–16% when planned with 100 MeV compared to 60 MeV, but there was no further improvement in the 120 MeV plan. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams, but to a more modest degree (<8%). While pencil beam spacing and SAD had a small effect on VHEE dose distributions, 0.1–3 mm pencil beam sizes resulted in identical dose distributions. For the 100 MeV VHEE pediatric

  2. 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.

  3. Assessment and treatment of planning skills in adolescents with ADHD

    OpenAIRE

    Boyer, B. E.

    2016-01-01

    Planning problems are described to be prominent in the daily lives of adolescents with ADHD (Barkley, 2004) and may cause comorbid conditions and impairments (Safren, 2006). Therefore the central aim of this thesis was to assess planning skills of adolescents with ADHD and to investigate whether these planning skills can be enhanced using cognitive behavioral therapy (CBT). Chapter 2 suggests that even though adolescents with ADHD show planning problems as compared to typically developing (TD...

  4. Neuromodulation therapies and treatment-resistant depression

    Directory of Open Access Journals (Sweden)

    Al-Harbi KS

    2012-07-01

    Full Text Available Khalid Saad Al-Harbi,1 Naseem Akhtar Qureshi21National Guard Hospital, King Abdulaziz Medical City, Riyadh, Saudi Arabia; 2General Administration for Research and Studies and Mental Health and Social Services, Riyadh, Saudi ArabiaBackground: Patients with treatment-resistant depression (TRD who showed partial response to pharmacological and psychotherapeutic interventions need a trial of neuromodulation therapies (NTs.Objective: This paper aims to review evidence-based data on the use of NTs in TRD.Method: Using keywords and combined-word strategy, multiple computer searches of PubMed, Google Scholar, Quertle(R, and Medline were conducted for retrieving relevant articles published in English-language peer-reviewed journals (2000–2012. Those papers that addressed NTs in TRD were retained for extensive review.Results: Despite methodological challenges, a range of 30%–93% of TRD patients showed substantial improvement to one of the NTs. One hundred–percent improvement was reported in two single-case studies on deep brain stimulation. Some studies reported no benefits from transcranial direct current stimulation. NTs were reported to have good clinical efficacy, better safety margin, and benign side-effect profile. Data are limited regarding randomized clinical trials, long-term efficacy, and cost-effectiveness of these approaches. Both modified electroconvulsive therapy and magnetic seizure therapy were associated with reversible but disturbing neurocognitive adverse effects. Besides clinical utility, NTs including approaches on the horizon may unlock the biological basis underlying mood disorders including TRD.Conclusion: NTs are promising in patients with TRD, as the majority of them show good clinical response measured by standardized depression scales. NTs need further technological refinements and optimization together with continuing well-designed studies that recruit larger numbers of participants with TRD.Keywords: treatment

  5. Vision 20/20: Positron emission tomography in radiation therapy planning, delivery, and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Parodi, Katia, E-mail: Katia.parodi@physik.uni-muenchen.de [Faculty of Physics, Department of Medical Physics, Ludwig Maximilians University Munich, Munich 85748 (Germany)

    2015-12-15

    Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved tumor delineation, and to assess the tumor response in follow-up investigations after or even during the course of fractionated therapy. Moreover, active research is being pursued on new tracers capable of providing different insights into tumor function, in order to identify areas of the planning volume which may require additional dosage for improved probability of tumor control. In this respect, major progresses in the next years will likely concern the development and clinical investigation of novel tracers and image processing techniques for reliable thresholding and segmentation, of treatment planning and beam delivery approaches integrating the PET imaging information, as well as improved multimodal clinical instrumentation such as PET/MR. But especially in the rapidly emerging case of ion beam therapy, the usage of PET is not only limited to the imaging of external tracers injected to the patient. In fact, a minor amount of positron emitters is formed in nuclear fragmentation reactions between the impinging ions and the tissue, bearing useful information for confirmation of the delivered treatment during or after therapeutic irradiation. Different implementations of unconventional PET imaging for therapy monitoring are currently being investigated clinically, and major ongoing research aims at new dedicated detector technologies and at challenging applications such as real-time imaging and time-resolved in vivo verification of motion compensated beam delivery. This paper provides an overview of the different areas of application of PET in radiation oncology and discusses the most promising perspectives in the years to come for radiation therapy

  6. Investigational therapies for the treatment of narcolepsy.

    Science.gov (United States)

    de Biase, Stefano; Nilo, Annacarmen; Gigli, Gian Luigi; Valente, Mariarosaria

    2017-08-01

    Narcolepsy is a chronic sleep disorder characterized by a pentad of excessive daytime sleepiness (EDS), cataplexy, sleep paralysis, hypnagogic/hypnopompic hallucinations, and disturbed nocturnal sleep. While non-pharmacological treatments are sometimes helpful, more than 90% of narcoleptic patients require a pharmacological treatment. Areas covered: The present review is based on an extensive Internet and PubMed search from 1994 to 2017. It is focused on drugs currently in development for the treatment of narcolepsy. Expert opinion: Currently there is no cure for narcolepsy, with treatment focusing on symptoms control. However, these symptomatic treatments are often unsatisfactory. The research is leading to a better understanding of narcolepsy and its symptoms. New classes of compounds with possible applications in the development of novel stimulant/anticataplectic medications are described. H3 receptor antagonists represent a new therapeutic option for EDS in narcolepsy. JZP-110, with its distinct mechanism of action, would be a new therapeutic option for the treatment of EDS in the coming years. In the future, hypocretin-based therapies and immune-based therapies, could modify the clinical course of the disease. However, more information would be necessary to completely understand the autoimmune process and also how this process can be altered for therapeutic benefits.

  7. 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.

  8. [Antithrombotic therapy in patients with atrial flutter before planned cardioversion].

    Science.gov (United States)

    М'якінькова, Людмила О; Тесленко, Юрій В; Пустовойт, Ганна Л; Ярмола, Тетяна І; Циганенко, Ірина В

    atrium flutter and fibrillation are the heart rhythm disorders that increase the risk of life-dangerous complications, e.g. cardioembolic stroke, pulmonary embolism. Recommendations for managing patients with atrial fibrillation - atrial flutter, with paroxysm duration over 48 hours, demand anticoagulant therapy. Oral anticoagulants, which are the antagonists of K vitamin (Varpharin) and the new oral anticoagulants (Rivaroxaban), are used during the per-manipulative procedure of patients with atrial flutter before restoring the sinus rhythm with transesophageal cardiac pacing. the present investigation aims to compare efficiency and safety of Varpharin and Rivaaroxaban in treatment patients with atrial flutter before planned cardioversion with transesophageal heart pacing. Varpharin (control group) - in doses equivalent for reaching the target МНВ - or Rivaroxaban (research group), 20 mg., were prescribed to 42 patients with coronary heart disease, concomitant arterial hypertension, and non-valvular paroxysm of atrial flutter with more than 48-hour duration, divided into two groups. There was held the general clinical, echocardioscopy examination. Thrombotic Risk Factor Assessment was made according to the CHA2DS2-VASc scale, Hemorrhagic Risk Factor Assessment was performed according to the HAS-BLED scale, and clinical symptoms assessment was made according to the EHRA scale. The heart rhythm was restored with the transesophageal heart pacing. the per-manipulative procedure of the patients of research group (21 days were suggested according to the guidelines) shortened, unlike the patients of control group (the period of target МНВ selection had made 30,76±0,62days), the reduction of the symptoms severity by EHRA was considered in dynamics. According to the results of transesophageal heart pacing, the heart rhythm of 15 research group patients restored, and 6 research group patients had atrial fibrillation. Among the patients of the control group, 6 had

  9. Quality control of the treatment planning systems dose calculations in external radiation therapy using the Penelope Monte Carlo code; Controle qualite des systemes de planification dosimetrique des traitements en radiotherapie externe au moyen du code Monte-Carlo Penelope

    Energy Technology Data Exchange (ETDEWEB)

    Blazy-Aubignac, L

    2007-09-15

    The treatment planning systems (T.P.S.) occupy a key position in the radiotherapy service: they realize the projected calculation of the dose distribution and the treatment duration. Traditionally, the quality control of the calculated distribution doses relies on their comparisons with dose distributions measured under the device of treatment. This thesis proposes to substitute these dosimetry measures to the profile of reference dosimetry calculations got by the Penelope Monte-Carlo code. The Monte-Carlo simulations give a broad choice of test configurations and allow to envisage a quality control of dosimetry aspects of T.P.S. without monopolizing the treatment devices. This quality control, based on the Monte-Carlo simulations has been tested on a clinical T.P.S. and has allowed to simplify the quality procedures of the T.P.S.. This quality control, in depth, more precise and simpler to implement could be generalized to every center of radiotherapy. (N.C.)

  10. Direct leaf trajectory optimization for volumetric modulated arc therapy planning with sliding window delivery

    Energy Technology Data Exchange (ETDEWEB)

    Papp, Dávid, E-mail: Papp.David@mgh.harvard.edu; Unkelbach, Jan [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, 30 Fruit Street, Boston, Massachusetts 02114 (United States)

    2014-01-15

    Purpose: The authors propose a novel optimization model for volumetric modulated arc therapy (VMAT) planning that directly optimizes deliverable leaf trajectories in the treatment plan optimization problem, and eliminates the need for a separate arc-sequencing step. Methods: In this model, a 360° arc is divided into a given number of arc segments in which the leaves move unidirectionally. This facilitates an algorithm that determines the optimal piecewise linear leaf trajectories for each arc segment, which are deliverable in a given treatment time. Multileaf collimator constraints, including maximum leaf speed and interdigitation, are accounted for explicitly. The algorithm is customized to allow for VMAT delivery using constant gantry speed and dose rate, however, the algorithm generalizes to variable gantry speed if beneficial. Results: The authors demonstrate the method for three different tumor sites: a head-and-neck case, a prostate case, and a paraspinal case. The authors first obtain a reference plan for intensity modulated radiotherapy (IMRT) using fluence map optimization and 20 intensity-modulated fields in equally spaced beam directions, which is beyond the standard of care. Modeling the typical clinical setup for the treatment sites considered, IMRT plans using seven or nine beams are also computed. Subsequently, VMAT plans are optimized by dividing the 360° arc into 20 corresponding arc segments. Assuming typical machine parameters (a dose rate of 600 MU/min, and a maximum leaf speed of 3 cm/s), it is demonstrated that the optimized VMAT plans with 2–3 min delivery time are of noticeably better quality than the 7–9 beam IMRT plans. The VMAT plan quality approaches the quality of the 20-beam IMRT benchmark plan for delivery times between 3 and 4 min. Conclusions: The results indicate that high quality treatments can be delivered in a single arc with 20 arc segments if sufficient time is allowed for modulation in each segment.

  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. A study of the plan dosimetric evaluation on the rectal cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hyun Hak; An, Beom Seok; Kim, Dae Il; Lee, Yang Hoon; Lee, Je Hee [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2016-12-15

    In order to minimize the dose of femoral head as an appropriate treatment plan for rectal cancer radiation therapy, we compare and evaluate the usefulness of 3-field 3D conformal radiation therapy(below 3fCRT), which is a universal treatment method, and 5-field 3D conformal radiation therapy(below 5fCRT), and Volumetric Modulated Arc Therapy (VMAT). The 10 cases of rectal cancer that treated with 21EX were enrolled. Those cases were planned by Eclipse(Ver. 10.0.42, Varian, USA), PRO3(Progressive Resolution Optimizer 10.0.28) and AAA(Anisotropic Analytic Algorithm Ver. 10.0.28). 3fCRT and 5fCRT plan has 0 degrees, 270 degrees, 90 degrees and 0 degrees, 95 degrees, 45 degrees, 315 degrees, 265 degrees gantry angle, respectively. VMAT plan parameters consisted of 15MV coplanar 360 degrees 1 arac. Treatment prescription was employed delivering 54Gy to recum in 30 fractions. To minimize the dose difference that shows up randomly on optimizing, VMAT plans were optimized and calculated twice, and normalized to the target V100%=95%. The indexes of evaluation are D of Both femoral head and aceta fossa, total MU, H.I.(Homogeneity index) and C.I.(Conformity index) of the PTV. All VMAT plans were verified by gamma test with portal dosimetry using EPID. D of Rt. femoral head was 53.08 Gy, 50.27 Gy, and 30.92 Gy, respectively, in the order of 3fCRT, 5fCRT, and VMAT treatment plan. Likewise, Lt. Femoral head showed average 53.68 Gy, 51.01 Gy and 29.23 Gy in the same order. D of Rt. aceta fossa was 54.86 Gy, 52.40 Gy, 30.37 Gy, respectively, in the order of 3fCRT, 5fCRT, and VMAT treatment plan. Likewise, Lt. Femoral head showed average 53.68 Gy, 51.01 Gy and 29.23 Gy in the same order. The maximum dose of both femoral head and aceta fossa was higher in the order of 3fCRT, 5fCRT, and VMAT treatment plan. C.I. showed the lowest VMAT treatment plan with an average of 1.64, 1.48, and 0.99 in the order of 3fCRT, 5fCRT, and VMAT treatment plan. There was no significant difference on H

  13. Atlas-guided prostate intensity modulated radiation therapy (IMRT) planning.

    Science.gov (United States)

    Sheng, Yang; Li, Taoran; Zhang, You; Lee, W Robert; Yin, Fang-Fang; Ge, Yaorong; Wu, Q Jackie

    2015-09-21

    An atlas-based IMRT planning technique for prostate cancer was developed and evaluated. A multi-dose atlas was built based on the anatomy patterns of the patients, more specifically, the percent distance to the prostate and the concaveness angle formed by the seminal vesicles relative to the anterior-posterior axis. A 70-case dataset was classified using a k-medoids clustering analysis to recognize anatomy pattern variations in the dataset. The best classification, defined by the number of classes or medoids, was determined by the largest value of the average silhouette width. Reference plans from each class formed a multi-dose atlas. The atlas-guided planning (AGP) technique started with matching the new case anatomy pattern to one of the reference cases in the atlas; then a deformable registration between the atlas and new case anatomies transferred the dose from the atlas to the new case to guide inverse planning with full automation. 20 additional clinical cases were re-planned to evaluate the AGP technique. Dosimetric properties between AGP and clinical plans were evaluated. The classification analysis determined that the 5-case atlas would best represent anatomy patterns for the patient cohort. AGP took approximately 1 min on average (corresponding to 70 iterations of optimization) for all cases. When dosimetric parameters were compared, the differences between AGP and clinical plans were less than 3.5%, albeit some statistical significances observed: homogeneity index (p  >  0.05), conformity index (p  Atlas-guided treatment planning is feasible and efficient. Atlas predicted dose can effectively guide the optimizer to achieve plan quality comparable to that of clinical plans.

  14. [Decision Support for the Therapy Planning for Young Refugees and Asylum-Seekers with Posttraumatic Disorders].

    Science.gov (United States)

    Reher, Cornelia; Metzner, Franka

    2016-12-01

    Decision Support for the Therapy Planning for Young Refugees and Asylum-Seekers with Posttraumatic Disorders Due to the Convention on the Rights of the Child and § 6 of the Asylum Seekers' Benefit Act, there are legal and ethical obligations for the care of minor refugees suffering from trauma-related disorders. In Germany, psychotherapeutic care of adolescent refugees is provided by specialized treatment centers and Child and Adolescent psychiatries with specialized consultation-hours for refugees. Treatment of minor refugees is impeded by various legal and organizational barriers. Many therapists have reservations and uncertainties regarding an appropriate therapy for refugees due to a lack of experience. This means that only a fraction of the young refugees with trauma-related disorders find an ambulatory therapist. In a review of international literature, empirical findings on (interpreter-aided) diagnostics and therapy of young refugees were presented. Practical experiences on therapeutic work with traumatized young refugees were summarized in a decision tree for therapy planning in the ambulatory setting. The decision tree was developed to support therapists in private practices by structuring the therapy process.

  15. Intensity-modulated radiation therapy to bilateral lower limb extremities concurrently: a planning case study

    Energy Technology Data Exchange (ETDEWEB)

    Fitzgerald, Emma, E-mail: emmafitz1390@gmail.com; Miles, Wesley; Fenton, Paul; Frantzis, Jim [Radiation Oncology, Epworth HealthCare, Victoria (Australia)

    2014-09-15

    Non-melanomatous skin cancers represent 80% of all newly diagnosed cancers in Australia with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) being the most common. A previously healthy 71-year-old woman presented with widespread and tender superficial skin cancers on the lower bilateral limbs. External beam radiation therapy through the use of intensity-modulated radiation therapy (IMRT) was employed as the treatment modality of choice as this technique provides conformal dose distribution to a three-dimensional treatment volume while reducing toxicity to surrounding tissues. The patient was prescribed a dose of 60 Gy to the planning target volume (PTV) with 1.0 cm bolus over the ventral surface of each limb. The beam arrangement consisted of six treatment fields that avoided entry and exit through the contralateral limb. The treatment plans met the International Commission on Radiation Units and Measurements (ICRU) guidelines and produced highly conformal dosimetric results. Skin toxicity was measured against the National Cancer Institute: Common Terminology Criteria for Adverse Events (NCI: CTCAE) version 3. A well-tolerated treatment was delivered with excellent results given the initial extent of the disease. This case study has demonstrated the feasibility and effectiveness of IMRT for skin cancers as an alternative to surgery and traditional superficial radiation therapy, utilising a complex PTV of the extremities for patients with similar presentations.

  16. 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.

  17. Direct leaf trajectory optimization for volumetric modulated arc therapy planning with sliding window delivery

    CERN Document Server

    Papp, Dávid

    2013-01-01

    We propose a novel optimization model for volumetric modulated arc therapy (VMAT) planning that directly optimizes deliverable leaf trajectories in the treatment plan optimization problem, and eliminates the need for a separate arc-sequencing step. In this model, a 360-degree arc is divided into a given number of arc segments in which the leaves move unidirectionally. This facilitates an algorithm that determines the optimal piecewise linear leaf trajectories for each arc segment, which are deliverable in a given treatment time. Multi-leaf collimator (MLC) constraints, including maximum leaf speed and interdigitation, are accounted for explicitly. The algorithm is customized to allow for VMAT delivery using constant gantry speed and dose rate, however, the algorithm generalizes to variable gantry speed if beneficial. We demonstrate the method for three different tumor sites: a head-and-neck case, a prostate case, and a paraspinal case. For that purpose, we first obtain a reference plan for intensity modulated...

  18. Radiotherapy Treatment Planning for Testicular Seminoma

    Energy Technology Data Exchange (ETDEWEB)

    Wilder, Richard B., E-mail: richardbwilder@yahoo.com [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States); Buyyounouski, Mark K. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Efstathiou, Jason A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Beard, Clair J. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center, Boston, MA (United States)

    2012-07-15

    Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

  19. 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

  20. Dosimetric and Biologic Differences in Flattened and Flattening-Filter-Free Beam Treatment Plans

    CERN Document Server

    Yan, Yue; Bassetti, Michael; Du, Kaifang; Saenz, Daniel; Harari, Paul; Paliwal, Bhudatt R

    2015-01-01

    Purpose: To quantitatively compare the dosimetric and biologic differences in treatment plans from flattened and flattening-filter-free (FFF) beam for three anatomic cancer sites. Methods and Materials: Treatment plans with static intensity-modulated radiotherapy beams and volumetric modulated arc therapy beams were generated for 13 patients for both the flattened beam and the FFF beam of the TrueBeam system. Beam energies of 6 MV and 10 MV were chosen for planning. A total of 104 treatment plans were generated in 13 patients. In order to analyze the biological effectiveness of treatment plans, dose volume histograms (DVH) were utilized. Flattened and FFF beam plans are quantitatively compared. Results: In head and neck cases, for VMAT plans, dose reduction in the FFF beam plans compared to the flattened beam in left cochlea, right submandibular gland and right parotid gland reached up to 2.36 Gy, 1.21 Gy and 1.45 Gy, respectively. Similarly, for static IMRT plans, the dose reduction of the FFF beam plans com...

  1. Intensity modulated radiation therapy planning for patients with a metal hip prosthesis based on class solutions.

    Science.gov (United States)

    van der Est, Henrie; Prins, Paulette; Heijmen, Ben J M; Dirkx, Maarten L P

    2012-01-01

    With the aging of the population, an increasing number of patients with metallic hip implants are referred for radiotherapy treatment. Class solutions for intensity modulated radiation therapy (IMRT) treatment planning are generally not applicable for these patients due to the required avoidance of dose delivery through prostheses. In this work a new approach for IMRT planning is presented, allowing the use of a default beam setup. For IMRT planning, Monaco (Elekta; CMS Software, Maryland Heights, MO) was used. In addition to the target and organs at risk, so-called prosthesis avoidance volumes (PAVs) were delineated in the beam's eye view projection for beams in which the prosthesis was partially in front of the target. By putting strict constraints on these virtual organs at risk, entrance dose delivery through a prosthesis is avoided while exit dose delivery is allowed. In this way, uncertainties in the dose delivery to the target and organs at risk, as derived by the treatment planning system, are largely minimized. To show the advantages of this IMRT-PAV technique, for 2 prostate cancer patients, 1 with bilateral and the other with unilateral metallic hip prostheses, obtained IMRT plans were compared with conventional IMRT plans using a prosthesis-avoiding beam setup. For both IMRT techniques a similar planning target volume coverage was achieved, but with the IMRT-PAV technique the mean doses to the bladder and the rectum were reduced by up to 25%. While the IMRT-PAV technique required more time for delineation, the time for treatment planning reduced because the default beam setup could be applied. The number of segments needed for dose delivery was comparable for both techniques. With the new IMRT-PAV technique IMRT class solutions can safely be applied for cancer patients with metallic hip prostheses, generally yielding a reduced dose delivery to organs at risk or improved target coverage. Copyright © 2012 American Society for Radiation Oncology

  2. SU-F-T-453: Improved Head and Neck SBRT Treatment Planning Using PlanIQ

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H; Wang, C; Phan, J; Tung, S; Chi, P [University of Texas, M.D. Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: Treatment planning for Head and Neck(HN) re-irradiation is a challenge because of ablative doses to target volume and strict critical structure constraints. PlanIQ(Sun Nuclear Corporation) can assess the feasibility of clinical goals and quantitatively measure plan quality. Here, we assess whether incorporation of PlanIQ in our SBRT treatment planning process can improve plan quality and planning efficiency. Methods: From 2013–2015, 35 patients (29 retrospective, 6 prospective) with recurrent HN tumors were treated with SBRT using VMAT treatment plans. The median prescription dose was 45 Gy in 5 fractions. We retrospectively reviewed the treatment plans and physician directives of our first 29 patients and generated score functions of the dosimetric goals used in our practice and obtained a baseline histogram. We then re-optimized 12 plans that had potential to further reduce organs-at-risk (OAR) doses according to PlanIQ feasibility DVH and plan quality analysis and compared them to the original plans. We applied our new PlanIQ-assisted planning process for our 6 most recently treated patients and evaluated the plan quality and planning efficiency. Results: The mean plan quality metric(PQM) and feasibility adjusted PQM(APQM) scores of our initial 29 treatment plans were 77.1±13.1 and 88.7±11.9, respectively (0–100 scale). The PQM and APQM scores for the 12 optimized plans improved from 75.9±11.0 and 85.1±10.2 to 80.7±9.3 and 90.2±8.0, respectively (p<0.005). Using our newly developed PlanIQ-assisted planning process, the PQM and APQM scores for the 6 most recently treated patients were 93.6±6.5 and 99.1±0.6, respectively. The planning goals were more straightforward to minimize OAR doses during optimization, thus less planning and revision time were used than before. Conclusion: PlanIQ has the potential to provide achievable planning goals and also improve plan quality and planning efficiency.

  3. Federal Facilities Compliance Act, Conceptual Site Treatment Plan. Part 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-10-29

    This Conceptual Site Treatment Plan was prepared by Ames Laboratory to meet the requirements of the Federal Facilities Compliance Act. Topics discussed in this document include: general discussion of the plan, including the purpose and scope; technical aspects of preparing plans, including the rationale behind the treatability groupings and a discussion of characterization issues; treatment technology needs and treatment options for specific waste streams; low-level mixed waste options; TRU waste options; and future waste generation from restoration activities.

  4. Sonodynamic therapy, a treatment developing from photodynamic therapy.

    Science.gov (United States)

    Rengeng, Liu; Qianyu, Zhang; Yuehong, Lang; Zhongzhong, Peng; Libo, Li

    2017-09-01

    Sonodynamic therapy (SDT) as a new non-invasive treatment developed from photodynamic (PDT), it can kill tumor cells specifically and selectively. Moreover, recently studies showed SDT has potential to treat solid tumor, leukemia and atherosclerosis, remove proliferative scars and kill pathogenic microorganism. As SDT has an extensive application prospect, SDT has attracted more and more research recently. This thesis aims to be an informative introduction on SDT. With the assistance of related literature from 2012 to 2016, we introduce the progress of SDT research in six aspects: the therapeutic mechanism of SDT, development of the sound sensitizer, exploration of the size and frequency of ultrasonic energy, application of SDT, comparison between SDT and PDT, and current situation and future of SDT. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Evaluation of deep inspiration breath-hold lung treatment plans with Monte Carlo dose calculation.

    Science.gov (United States)

    Yorke, Ellen D; Wang, Lu; Rosenzweig, Kenneth E; Mah, Dennis; Paoli, Jean-Baptiste; Chui, Chen-Shou

    2002-07-15

    To evaluate dosimetry of deep inspiration breath-hold (DIBH) relative to free breathing (FB) for three-dimensional conformal radiation therapy of lung cancer with 6-MV photons and Monte Carlo (MC) dose calculations. Static three-dimensional conformal radiation therapy, 6-MV plans, based on DIBH and FB CT images for five non-small-cell lung cancer patients, were generated on a clinical treatment planning system with equivalent path length tissue inhomogeneity correction. Margins of gross to planning target volume were not reduced for DIBH plans. Cord and lung toxicity determined the maximum treatment dose for each plan. Dose distributions were recalculated for the same beams with an MC dose calculation algorithm and electron density distributions derived from the CT images. MC calculations showed decreased target coverage relative to treatment-planning system predictions. Lateral disequilibrium caused more degradation of target coverage for DIBH than for FB (approximately 4% worse than expected for FB vs. 8% for DIBH). However, with DIBH higher treatment doses could be delivered without violating normal tissue constraints, resulting in higher total doses to gross target volume and to >99% of planning target volume. If DIBH enables prescription dose increases exceeding 10%, MC calculations indicate that, despite lateral disequilibrium, higher doses will be delivered to medium-to-large, partly mediastinal gross target volumes, providing that 6-MV photons are used and margins are not reduced.

  6. Evaluation of flexible and rigid (class solution) radiation therapy conformal prostate planning protocols

    Energy Technology Data Exchange (ETDEWEB)

    Coburn, Natalie, E-mail: natalie.coburn@swahs.health.nsw.gov.au [Radiation Oncology Network, Nepean Cancer Care Centre, University of Sydney, Sydney, New South Wales (Australia); Beldham-Collins, Rachael [Radiation Oncology Network, Nepean Cancer Care Centre, University of Sydney, Sydney, New South Wales (Australia); Radiation Oncology Network, Westmead Cancer Care Centre, University of Sydney, Sydney, New South Wales (Australia); Westling, Jelene; Trovato, Jenny [Radiation Oncology Network, Nepean Cancer Care Centre, University of Sydney, Sydney, New South Wales (Australia); Gebski, Val [National Health and Medical Research Council Clinical Trials Centre, University of Sydney, Sydney, New South Wales (Australia)

    2012-04-01

    Protocols commonly implemented in radiotherapy work areas may be classified as being either rigid (class solution) or flexible. Because formal evaluation of these protocol types has not occurred within the literature, we evaluated the efficiency of a rigid compared with flexible prostate planning protocol by assessing a series of completed 3D conformal prostate plans. Twenty prostate cancer patients with an average age of 70 years (range, 52-77) and sizes comprising 8 small, 10 medium, and 2 large were planned on the Phillips Pinnacle treatment planning system 6 times by radiation therapists with <2 years, 2-5 years, and >5 years of experience using a rigid and flexible protocol. Plans were critiqued using critical organ doses, confirmation numbers, and conformity index. Plans were then classified as being acceptable or not. Plans produced with the flexible protocol were 53% less likely to require modification (OR 0.47, 95% CI: 0.26, 0.84, p = 0.01). Planners with >5 years of experience were 78% more likely to produce plans requiring modification (OR 1.78, 95% CI: 1.12, 2.83, P = 0.02). Plans according to the flexible protocol took longer (112 min) compared with the time taken using a rigid protocol (68 min) (p < 0.001). The results suggest that further studies are needed; however, we propose that all radiation therapy planners should start with the same limitations, and if an acceptable plan is not reached, then flexibility should be given to improve the plan to meet the desired results.

  7. 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.

  8. Introduction to Radiotherapy with Photon and Electron Beams and Treatment Planning from Conformal Radiotherapy to IMRT

    Science.gov (United States)

    Wilkens, Jan J.

    2007-11-01

    Besides surgery and chemotherapy, radiation therapy is one of the three main treatment options for cancer patients. This paper provides an introduction to the basic principles of radiotherapy with photons and electrons. It includes a brief summary of the physical properties for photon and electron beams as well as a description of treatment machines used to create these beams. The second part introduces the treatment planning process as it is commonly employed in radiotherapy. It covers dose calculation algorithms, conventional planning strategies for three-dimensional conformal radiotherapy, and optimization techniques for intensity modulated radiotherapy (IMRT).

  9. Automation of radiation treatment planning. Evaluation of head and neck cancer patient plans created by the Pinnacle{sup 3} scripting and Auto-Planning functions

    Energy Technology Data Exchange (ETDEWEB)

    Speer, Stefan; Weiss, Alexander; Bert, Christoph [Universitaetsklinikum Erlangen, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Department of Radiation Oncology, Erlangen (Germany); Klein, Andreas [EKS Engineering GmbH, Fuerth (Germany); Kober, Lukas [Strahlentherapie Tauber-Franken, Bad Mergentheim (Germany); Yohannes, Indra [Rinecker Proton Therapy Center, Munich (Germany)

    2017-08-15

    Intensity-modulated radiotherapy (IMRT) techniques are now standard practice. IMRT or volumetric-modulated arc therapy (VMAT) allow treatment of the tumor while simultaneously sparing organs at risk. Nevertheless, treatment plan quality still depends on the physicist's individual skills, experiences, and personal preferences. It would therefore be advantageous to automate the planning process. This possibility is offered by the Pinnacle{sup 3} treatment planning system (Philips Healthcare, Hamburg, Germany) via its scripting language or Auto-Planning (AP) module. AP module results were compared to in-house scripts and manually optimized treatment plans for standard head and neck cancer plans. Multiple treatment parameters were scored to judge plan quality (100 points = optimum plan). Patients were initially planned manually by different physicists and re-planned using scripts or AP. Script-based head and neck plans achieved a mean of 67.0 points and were, on average, superior to manually created (59.1 points) and AP plans (62.3 points). Moreover, they are characterized by reproducibility and lower standard deviation of treatment parameters. Even less experienced staff are able to create at least a good starting point for further optimization in a short time. However, for particular plans, experienced planners perform even better than scripts or AP. Experienced-user input is needed when setting up scripts or AP templates for the first time. Moreover, some minor drawbacks exist, such as the increase of monitor units (+35.5% for scripted plans). On average, automatically created plans are superior to manually created treatment plans. For particular plans, experienced physicists were able to perform better than scripts or AP; thus, the benefit is greatest when time is short or staff inexperienced. (orig.) [German] Intensitaetsmodulierte Strahlentherapie (IMRT) hat sich als Standard durchgesetzt. Mit IMRT oder volumenmodulierter Arc-Therapie (VMAT) lassen sich

  10. Cell survival probability in a spread-out Bragg peak for novel treatment planning

    Science.gov (United States)

    Surdutovich, Eugene; Solov'yov, Andrey V.

    2017-08-01

    The problem of variable cell survival probability along the spread-out Bragg peak is one of the long standing problems in planning and optimisation of ion-beam therapy. This problem is considered using the multiscale approach to the physics of ion-beam therapy. The physical reasons for this problem are analysed and understood on a quantitative level. A recipe of solution to this problem is suggested using this approach. This recipe can be used in the design of a novel treatment planning and optimisation based on fundamental science.

  11. Photodynamic therapy for treatment subretinal neovascularization

    Science.gov (United States)

    Avetisov, Sergey E.; Budzinskaja, Maria V.; Kiseleva, Tatyana N.; Balatskaya, Natalia V.; Gurova, Irina V.; Loschenov, Viktor B.; Shevchik, Sergey A.; Kuzmin, Sergey G.; Vorozhtsov, Georgy N.

    2007-07-01

    This work are devoted our experience with photodynamic therapy (PDT) with > for patients with choroidal neovascularization (CNV). 18 patients with subfoveal CNV in age-related macular degeneration (AMD), 24 patients with subfoveal CNV in pathological myopia (PM) and 4 patients with subfoveal CNV associated with toxoplasmic retinochoroiditis were observed. CNV was 100% classic in all study patients. Standardized protocol refraction, visual acuity testing, ophthalmologic examinations, biomicroscopy, fluorescein angiography, and ultrasonography were performed before treatment and 1 month, 3 months, 6 months, and 1 year after treatment; were used to evaluate the results of photodynamic therapy with > (0.02% solution of mixture sulfonated aluminium phtalocyanine 0.05 mg/kg, intravenously). A diode laser (>, Inc, Moscow) was used operating in the range of 675 nm. Need for retreatment was based on fluorescein angiographic evidence of leakage at 3-month follow-up intervals. At 3, 6, 9 month 26 (56.5%) patients had significant improvement in the mean visual acuity. At the end of the 12-month minimal fluorescein leakage from choroidal neovascularization was seen in 12 (26.1%) patients and the mean visual acuity was slightly worse than 0.2 which was not statistically significant as compared with the baseline visual acuity. Patients with fluorescein leakage from CNV underwent repeated PDT with >. 3D-mode ultrasound shown the decreasing thickness of chorioretinal complex in CNV area. Photodynamic therapy with > can safely reduce the risk of severe vision loss in patients with predominantly classic subfoveal choroidal neovascularization secondary to AMD, PM and toxoplasmic retinochoroiditis.

  12. Application of Magnetic Resonance Imaging and Three-Dimensional Treatment Planning in the Treatment of Orbital Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Rudoltz, Marc S. [Department of Radiation Oncology And Nuclear Medicine, Thomas Jefferson University Hospital, Philadelphia, PA, 19107 (United States); Ayyangar, Komanduri [Department of Radiation Therapy, Medical College of Ohio, Toledo, OH43699 (United States); Mohiuddin, Mohammed [Department of Radiation Oncology And Nuclear Medicine, Thomas Jefferson University Hospital, Philadelphia, PA, 19107 (United States)

    2015-01-15

    Radiotherapy for lymphoma of the orbit must be individualized for each patient and clinical setting. Most techniques focus on optimizing the dose to the tumor while sparing the lens. This study describes a technique utilizing magnetic resonance imaging (MRI) and three dimensional (3D) planning in the treatment of orbital lymphoma. A patient presented with an intermediate grade lymphoma of the right orbit. The prescribed tumor dose was 4050 cGy in 18 fractions. Three D planning was carried out and tumor volumes, retina, and lens were subsequently outlined. Dose calculations including dose volume histograms of the target, retina, and lens were then performed. Part of the retina was outside of the treatment volume while 50% of the retina received 90% or more of the prescribed dose. The patient was clinically NED when last seen 2 years following therapy with no treatment-related morbidity. Patients with lymphomas of the orbit can be optimally treated using MRI based 3D treatment planning.

  13. Implementation of hypoxia imaging into treatment planning and delivery.

    Science.gov (United States)

    Thorwarth, Daniela; Alber, Markus

    2010-11-01

    To review the current status of implementation of functional hypoxia imaging in radiotherapy (RT) planning and treatment delivery. Before biological imaging techniques such as positron emission tomography (PET) or magnetic resonance (MR) can be used for individual RT adaptation, three main requirements have to be fulfilled. First, tissue parameters have to be derived from the imaging data that correlate with individual therapy outcome. Then, the spatial and temporal stability of hypoxia PET images needs to be established. Finally, the dose painting (DP) concepts have to be practically feasible to be used as a basis for clinical trials. A number of recent clinical studies could show the correlation of hypoxia PET imaging with different tracers and RT outcome. Most of the studies revealed a correlation between mean or maximum values and parameters assessed from the PET avid volume and treatment success, only few investigations used quantitative imaging. Multiparametric imaging seems to be very valuable. Recently, the spatial and temporal stability of hypoxia PET attracted attention. Temporal changes in the distribution of functional tumour properties were reported. Furthermore, technical feasibility of DP by contours (DPC) as well as DP by numbers (DPBN) was shown by several investigators. The challenge is now to design clinical studies in order to prove the impact of DP treatments on individual therapy success. A patient-specific adaptation of RT based on functional hypoxia imaging with PET is possible and promising. Conceptual feasibility could be shown for DPBN whereas to date, only DPC seems to be plausible and feasible in a clinical context. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  14. Brain Malignancy Steering Committee clinical trials planning workshop: report from the Targeted Therapies Working Group.

    Science.gov (United States)

    Alexander, Brian M; Galanis, Evanthia; Yung, W K Alfred; Ballman, Karla V; Boyett, James M; Cloughesy, Timothy F; Degroot, John F; Huse, Jason T; Mann, Bhupinder; Mason, Warren; Mellinghoff, Ingo K; Mikkelsen, Tom; Mischel, Paul S; O'Neill, Brian P; Prados, Michael D; Sarkaria, Jann N; Tawab-Amiri, Abdul; Trippa, Lorenzo; Ye, Xiaobu; Ligon, Keith L; Berry, Donald A; Wen, Patrick Y

    2015-02-01

    Glioblastoma is the most common primary brain malignancy and is associated with poor prognosis despite aggressive local and systemic therapy, which is related to a paucity of viable treatment options in both the newly diagnosed and recurrent settings. Even so, the rapidly increasing number of targeted therapies being evaluated in oncology clinical trials offers hope for the future. Given the broad range of possibilities for future trials, the Brain Malignancy Steering Committee convened a clinical trials planning meeting that was held at the Udvar-Hazy Center in Chantilly, Virginia, on September 19 and 20, 2013. This manuscript reports the deliberations leading up to the event from the Targeted Therapies Working Group and the results of the meeting. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. The effect of photon energy on the intensity-modulated radiation therapy plan for prostate cancer: a planning study

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin-Beom; Kim, Jae-Sung; Kim, In-Ah [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Lee, Jeong-Woo [Konkuk University Hospital, Seoul (Korea, Republic of); Korea University, Seoul (Korea, Republic of); Cho, Woong; Suh, Tae-Suk [The Catholic University of Korea, Seoul (Korea, Republic of)

    2011-07-15

    In this study, the effect of the beam energy on the intensity modulated radiation therapy (IMRT) plan for prostate cancer was studied for competing IMRT plans optimized for delivery with either 6- or 15-MV photons. This retrospective planning study included 10 patients treated for localized prostate cancer at the Seoul National University Bundang Hospital. A dose of 66 Gy was prescribed in 33 daily fractions of 2 Gy. For inverse IMRT treatment planning, we used a 7-coplanar non-opposed beam arrangement at 0, 50, 100, 150, 210, 260, and 310 degree angles. To ensure that differences among the plans were due only to energy selection, the beam arrangement, number of beam, and dose constraints were kept constant for all plans. The dose volume histograms (DVHs) for the 6- and 15-MV plans were compared for the planning target volume (PTV) and for organs at risk (OAR), such as the rectum, bladder and both femoral heads. The conformal index was defined as the ratio of the 95% isodose volume divided by the PTV volume enclosed by the 95% isodose line, because we selected the 95% isodose line as our reference. Doses received by the 95% and 5% volume of the PTV were less than or equal to 1% for 6-MV compared to the 15-MV IMRT plan for 10 patients. Percentage of doses received by the 10% volume of the bladder and rectum were less than or equal to 1%. Percentage of doses received by the 30 and 50% volume of bladder and rectum were 1 {approx} 2% higher for 6-MV photons. Also, percentage of dose received by the 10% and 50% volume of the right and the left femur heads were 4 {approx} 5% higher for 6-MV photons. The mean homogeneity index for the 6-MV and 15-MV photon plans was 1.06. The mean conformity index of 95% was 1.04 {+-} 0.01 and 1.12 {+-} 0.02 for 6-MV and 15-MV, respectively, but this difference was not statistically significant. The mean monitor unit was 812 {+-} 40 and 716 {+-} 33 for the 6-MV and the 15-MV photon plans, respectively. The 6-MV photon plan delivers 13

  16. MINERVA - A Multi-Modal Radiation Treatment Planning System

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Wessol; C. A. Wemple; D. W. Nigg; J. J. Cogliati; M. L. Milvich; C. Frederickson; M. Perkins; G. A. Harkin

    2004-10-01

    Recently, research efforts have begun to examine the combination of BNCT with external beam photon radiotherapy (Barth et al. 2004). In order to properly prepare treatment plans for patients being treated with combinations of radiation modalities, appropriate planning tools must be available. To facilitiate this, researchers at the Idaho National Engineering and Environmental Laboratory (INEEL)and Montana State University (MSU) have undertaken development of a fully multi-modal radiation treatment planning system.

  17. Impact of machines on plan quality: volumetric modulated arc therapy and intensity modulated radiation therapy.

    Science.gov (United States)

    Clemente, S; Cozzolino, M; Oliviero, C; Fiorentino, A; Chiumento, C; Fusco, V

    2014-02-01

    To evaluate the impact of different machines on plan quality using both intensity modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques. Eight patients with squamous cell carcinoma of the oropharynx were selected at random. Plans were computed for IMRT and VMAT Smart Arc, using Pinnacle TPS for an Elekta (IMRT-E, VMAT-E) and Varian linac (IMRT-V, VMAT-V). A three-dose level prescription was used to deliver 70, 63 and 58.1 Gy to regions of macroscopic, microscopic high- and low-risk disease, respectively. All doses were given in 35 fractions. Comparisons were performed on dose-volume histogram data, monitor units (MU), and delivery time. VMAT-E plans resulted slightly MU efficient (-24 % p < 0.05) compared to VMAT-V while IMRT-V shortened delivery time (-19 % p < 0.05) compared to IMRT-E. All the delivery techniques resulted in equivalent target coverage in terms of D(98) % and D(2) %. For VMAT technique, a significant improvement of 7 % in homogeneity index (HI) for PTV58.1 was observed for Varian machine. A slight improvement in OARs sparing was observed with Elekta machine both for IMRT and VMAT techniques. Similar plan quality was observed for Elekta and Varian linacs, significant differences were observed in delivery efficiency, as MU number and delivery times, in favor of Elekta and Varian, respectively.

  18. Review of yoga therapy during cancer treatment.

    Science.gov (United States)

    Danhauer, Suzanne C; Addington, Elizabeth L; Sohl, Stephanie J; Chaoul, Alejandro; Cohen, Lorenzo

    2017-04-01

    Reviews of yoga research that distinguish results of trials conducted during (versus after) cancer treatment are needed to guide future research and clinical practice. We therefore conducted a review of non-randomized studies and randomized controlled trials of yoga interventions for children and adults undergoing treatment for any cancer type. Studies were identified via research databases and reference lists. Inclusion criteria were the following: (1) children or adults undergoing cancer treatment, (2) intervention stated as yoga or component of yoga, and (3) publication in English in peer-reviewed journals through October 2015. Exclusion criteria were the following: (1) samples receiving hormone therapy only, (2) interventions involving meditation only, and (3) yoga delivered within broader cancer recovery or mindfulness-based stress reduction programs. Results of non-randomized (adult n = 8, pediatric n = 4) and randomized controlled trials (adult n = 13, pediatric n = 0) conducted during cancer treatment are summarized separately by age group. Findings most consistently support improvement in psychological outcomes (e.g., depression, distress, anxiety). Several studies also found that yoga enhanced quality of life, though further investigation is needed to clarify domain-specific efficacy (e.g., physical, social, cancer-specific). Regarding physical and biomedical outcomes, evidence increasingly suggests that yoga ameliorates sleep and fatigue; additional research is needed to advance preliminary findings for other treatment sequelae and stress/immunity biomarkers. Among adults undergoing cancer treatment, evidence supports recommending yoga for improving psychological outcomes, with potential for also improving physical symptoms. Evidence is insufficient to evaluate the efficacy of yoga in pediatric oncology. We describe suggestions for strengthening yoga research methodology to inform clinical practice guidelines.

  19. Local antimicrobial therapy after initial periodontal treatment.

    Science.gov (United States)

    Salvi, Giovanni E; Mombelli, Andrea; Mayfield, Lisa; Rutar, Alexandra; Suvan, Jean; Garrett, Steven; Lang, Niklaus P

    2002-06-01

    The aim of this single-blind, randomized, parallel-designed clinical trial (RCT) was to evaluate the clinical and microbiological effects of three sustained-release biodegradable polymers delivered into periodontal pockets following initial periodontal therapy. Forty-seven patients (28 females and 19 males) with a mean age of 51 years (range 29-71) underwent a periodontal examination at baseline (i.e. Week 0) and after 18 weeks. This included the assessment of the Plaque Index (PlI), Bleeding on Probing (BOP), Pocket Probing Depths (PPD) and Probing Attachment Levels (PAL) at six sites per tooth. Two to 4 months prior to baseline, all subjects had received initial periodontal therapy including motivation, instruction in oral hygiene practices and full-mouth scaling and root planing. At the treatment appointment (i.e. Week 2), the patients were randomly assigned to receive either Atridox trade mark, Elyzol Dental Gel or PerioChip at all residual periodontal pockets with a probing depth >/= 5 mm and concomitant BOP. In accordance with the manufacturer's recommendations, Elyzol Dental Gel was applied for a second time 7 days later. In addition to the clinical evaluation, subgingival microbiological samples were collected prior to treatment (i.e. Week 2) and at Weeks 4 and 18. Analysis of variance/covariance was used to evaluate changes from baseline to Week 18 for the clinical parameters. Between the baseline and 18-week examinations, subjects treated with Atridox showed a significantly greater gain in mean PAL of 0.33 mm +/- 0.09 (SD) than subjects treated with Elyzol Dental Gel [0.03 mm +/- 0.09 (SD)](p = 0.03). However, the gain in PAL of 0.16 mm +/- 0.10 (SD) found after PerioChip application did not differ significantly from that obtained following the application of Atridox(p = 0.27). Of the sites treated with Atridox, 42% gained >/= 1 mm PAL and 9% >/= 2 mm PAL as opposed to the sites treated with Elyzol Dental Gel, in which 34% gained >/= 1 mm PAL and 8

  20. Graves' disease radioiodine-therapy: Choosing target absorbed doses for therapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Willegaignon, J., E-mail: j.willegaignon@gmail.com; Sapienza, M. T.; Coura-Filho, G. B.; Buchpiguel, C. A. [Cancer Institute of São Paulo State (ICESP), Clinical Hospital, School of Medicine, University of São Paulo, São Paulo 01246-000 (Brazil); Nuclear Medicine Service, Department of Radiology, School of Medicine, University of São Paulo, Sao Paulo 01246-000 (Brazil); Watanabe, T. [Nuclear Medicine Service, Department of Radiology, School of Medicine, University of São Paulo, São Paulo 01246-000 (Brazil); Traino, A. C. [Unit of Medical Physics, Azienda Ospedaliero-Universitaria Pisana, Pisa 56126 (Italy)

    2014-01-15

    Purpose: The precise determination of organ mass (m{sub th}) and total number of disintegrations within the thyroid gland (A{sup ~}) are essential for thyroid absorbed-dose calculations for radioiodine therapy. Nevertheless, these parameters may vary according to the method employed for their estimation, thus introducing uncertainty in the estimated thyroid absorbed dose and in any dose–response relationship derived using such estimates. In consideration of these points, thyroid absorbed doses for Graves’ disease (GD) treatment planning were calculated using different approaches to estimating the m{sub th} and the A{sup ~}. Methods: Fifty patients were included in the study. Thyroid{sup 131}I uptake measurements were performed at 2, 6, 24, 48, 96, and 220 h postadministration of a tracer activity in order to estimate the effective half-time (T{sub eff}) of {sup 131}I in the thyroid; the thyroid cumulated activity was then estimated using the T{sub eff} thus determined or, alternatively, calculated by numeric integration of the measured time-activity data. Thyroid mass was estimated by ultrasonography (USG) and scintigraphy (SCTG). Absorbed doses were calculated with the OLINDA/EXM software. The relationships between thyroid absorbed dose and therapy response were evaluated at 3 months and 1 year after therapy. Results: The average ratio (±1 standard deviation) betweenm{sub th} estimated by SCTG and USG was 1.74 (±0.64) and that between A{sup ~} obtained by T{sub eff} and the integration of measured activity in the gland was 1.71 (±0.14). These differences affect the calculated absorbed dose. Overall, therapeutic success, corresponding to induction of durable hypothyroidism or euthyroidism, was achieved in 72% of all patients at 3 months and in 90% at 1 year. A therapeutic success rate of at least 95% was found in the group of patients receiving doses of 200 Gy (p = 0.0483) and 330 Gy (p = 0.0131) when m{sub th} was measured by either USG or SCTG and A

  1. Nitrate Waste Treatment Sampling and Analysis Plan

    Energy Technology Data Exchange (ETDEWEB)

    Vigil-Holterman, Luciana R. [Los Alamos National Laboratory; Martinez, Patrick Thomas [Los Alamos National Laboratory; Garcia, Terrence Kerwin [Los Alamos National Laboratory

    2017-07-05

    This plan is designed to outline the collection and analysis of nitrate salt-bearing waste samples required by the New Mexico Environment Department- Hazardous Waste Bureau in the Los Alamos National Laboratory (LANL) Hazardous Waste Facility Permit (Permit).

  2. Automated construction of an intraoperative high-dose-rate treatment plan library for the Varian brachytherapy treatment planning system.

    Science.gov (United States)

    Deufel, Christopher L; Furutani, Keith M; Dahl, Robert A; Haddock, Michael G

    2016-01-01

    The ability to create treatment plans for intraoperative high-dose-rate (IOHDR) brachytherapy is limited by lack of imaging and time constraints. An automated method for creation of a library of high-dose-rate brachytherapy plans that can be used with standard planar applicators in the intraoperative setting is highly desirable. Nonnegative least squares algebraic methods were used to identify dwell time values for flat, rectangular planar applicators. The planar applicators ranged in length and width from 2 cm to 25 cm. Plans were optimized to deliver an absorbed dose of 10 Gy to three different depths from the patient surface: 0 cm, 0.5 cm, and 1.0 cm. Software was written to calculate the optimized dwell times and insert dwell times and positions into a .XML plan template that can be imported into the Varian brachytherapy treatment planning system. The user may import the .XML template into the treatment planning system in the intraoperative setting to match the patient applicator size and prescribed treatment depth. A total of 1587 library plans were created for IOHDR brachytherapy. Median plan generation time was approximately 1 minute per plan. Plan dose was typically 100% ± 1% (mean, standard deviation) of the prescribed dose over the entire length and width of the applicator. Plan uniformity was best for prescription depths of 0 cm and 0.5 cm from the patient surface. An IOHDR plan library may be created using automated methods. Thousands of plan templates may be optimized and prepared in a few hours to accommodate different applicator sizes and treatment depths and reduce treatment planning time. The automated method also enforces dwell time symmetry for symmetrical applicator geometries, which simplifies quality assurance. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  3. Nominal standard dose and tumor standard dose. Tables for radiation therapy planning and analysis.

    Science.gov (United States)

    Kuisk, H; Khan, F M

    1975-01-01

    The method of treatment planning for a predetermined NSD value is described in detail using various example-problems. The Fret tables allow the finding of the total number of fractions needed (NT) for the NSD. This is done through the NSD/d ratio, d standing for the fractional dose in rad. The Fret tables are for 1 to 7 fractions-per-week treatment schedules. The corresponding value of T (elapsed days) are shown for different week days of the therapy initiation with their respective Fret and NSD/d values. The handling of the rest and multi-rest periods is described. A method of finding the NSD value for a treatment which has reached the maximum connective tissue tolerance is described, covering even the most complex treatment plans. Fret-tumor tables for NSD-tumor and their use are described by appropriate example-problems. Ret equivalent therapy planning through direct NSD methods (Fret tables) and through an approximation method (tables provided) is described and the usage demonstrated by example-problems. The usage of parallel opposing and multiple portals is evaluated in ret-dose values (peripheral radiobiologic effect) and certain conclusions drawn to guide the therapist. These show in which situations all portals per session should be used and when alternate portals are more beneficial. The effect of portal weighting is included in this analysis. The application of ELLIS' NSD method for radium therapy is described. If, in the future, any changes in the power factors of the present NSD formula become necessary, the basic handling of the NSD problems described in this manuscript will remain unchanged. The values obtained from these tables can then be adjusted by the appropriate factors.

  4. USE OF PROTON MAGNETIC RESONANCE SPECTROSCOPIC IMAGING DATA IN PLANNING FOCAL RADIATION THERAPIES FOR BRAIN TUMORS

    Directory of Open Access Journals (Sweden)

    Edward E Graves

    2011-05-01

    Full Text Available Advances in radiation therapy for malignant neoplasms have produced techniques such as Gamma Knife radiosurgery, capable of delivering an ablative dose to a specific, irregular volume of tissue. However, efficient use of these techniques requires the identification of a target volume that will produce the best therapeutic response while sparing surrounding normal brain tissue. Accomplishing this task using conventional computed tomography (CT and contrast-enhanced magnetic resonance imaging (MRI techniques has proven difficult because of the difficulties in identifying the effective tumor margin. Magnetic resonance spectroscopic imaging (MRSI has been shown to offer a clinically-feasible metabolic assessment of the presence and extent of neoplasm that can complement conventional anatomic imaging. This paper reviews current Gamma Knife protocols and MRSI acquisition, reconstruction, and interpretation techniques, and discusses the motivation for including magnetic resonance spectroscopy findings while planning focal radiation therapies. A treatment selection and planning strategy incorporating MRSI is then proposed, which can be used in the future to assess the efficacy of spectroscopy-based therapy planning.

  5. WE-A-BRD-01: MR Imaging for Treatment Planning: What Every Physicist Should Know

    Energy Technology Data Exchange (ETDEWEB)

    McGee, K. [Mayo Clinic (United States)

    2015-06-15

    Ever since its introduction as a diagnostic imaging modality over 30 years ago, the radiation therapy community has acknowledged the utility of MR imaging as a tool for not only improved visualization of the target volume but also for demarcation of adjacent organs at risk. However, the adaptation of MR imaging in radiation oncology has, until recently been slow due in large part to the inability to image radiation therapy patients in their treatment position. With the introduction of so-called wide bore high field MR scanners, multi element flexible receive only RF coils, high performance imaging gradients and a range of volumetric imaging sequences it is now possible to obtain both high resolution and high signal-to-noise ratio images of in-treatment radiation therapy patients within clinically feasible imaging times. As a Result, there is renewed interest in the use of MR imaging for radiation oncology treatment planning that is being translated into physical siting and integration of these systems into radiation oncology departments. As MR imaging expands into the radiation oncology domain there is a significant and unmet need for radiation therapy physicists to become educated regarding the strengths, limitations and technical challenges associated with MR imaging. The purpose of this presentation is to address this need by providing an educational overview of the techniques and challenges associated with MR imaging of patients for radiation therapy treatment planning. As such this presentation will: 1) describe the fundamental differences between imaging of patients for diagnostic and therapeutic purposes (i.e. radiation therapy planning), 2) describe most commonly used imaging sequences and contrasts for identification of disease for radiation planning, 3) identify the most common sources of image distortion and techniques to reduce their effect on spatial fidelity of the MR data, 4) describe the effects of motion and methods to quantify/correct it, and 5

  6. Clinical issues: music therapy in an adult cancer inpatient treatment setting.

    Science.gov (United States)

    O'Callaghan, Clare

    2006-01-01

    The adult oncology inpatient music therapy program at Peter MacCallum Cancer Center, which is Australia's only hospital solely dedicated to cancer treatment, research and care, is described. Patients' treatment requirements and often changing conditions compel music therapist to be flexible in their approach, offering both pre-planned treatment sessions and spontaneous sessions in open ward contexts. Patients and families who wish to engage im music therapy choose from various music therapy methods, including live song choice, music imagery and relaxation, therapeutic music lessons, and improvisation. Complex variables inevitable in such human relationship therapies necessitate that, alongside randomized controlled trials, research methods are grounded in the social sciences to meaningfully substantiate, and further advance, oncologic music therapy.

  7. Photodynamic therapy in treatment of severe oral lichen planus.

    Science.gov (United States)

    Rabinovich, O F; Rabinovich, I M; Guseva, A V

    2016-01-01

    The aim of the study was to elaborate the rationale for the application of photodynamic therapy in complex treatment of patient with severe oral lichen planus. Complex clinical and laboratory examination and treatment was performed in 54 patients divided on 3 groups. Diagnosis of oral lichen planus was based on clinical, histological and immunohistochemical features. Group 1 received standard treatment, in the second group photodynamic therapy was conducted in addition to conventional treatment, patients in the third group received only photodynamic therapy. The study results proved photodynamic therapy to be useful tool in complex treatment of severe oral lichen planus.

  8. The impact of leaf width and plan complexity on DMLC tracking of prostate intensity modulated arc therapy

    DEFF Research Database (Denmark)

    Pommer, Tobias; Falk, Marianne; Poulsen, Per Rugaard

    2013-01-01

    Purpose: Intensity modulated arc therapy (IMAT) is commonly used to treat prostate cancer. The purpose of this study was to evaluate the impact of leaf width and plan complexity on dynamic multileaf collimator (DMLC) tracking for prostate motion management during IMAT treatments.Methods: Prostate...

  9. Comparison of steroid pulse therapy and conventional oral steroid therapy as initial treatment for autoimmune pancreatitis.

    Science.gov (United States)

    Tomiyama, Takashi; Uchida, Kazushige; Matsushita, Mitsunobu; Ikeura, Tsukasa; Fukui, Toshiro; Takaoka, Makoto; Nishio, Akiyoshi; Okazaki, Kazuichi

    2011-05-01

    The efficacy of oral steroid therapy for autoimmune pancreatitis (AIP) is well known, and oral prednisolone treatment is most usually commenced at 30-40 mg/day, but there have been few reports about comparative studies of oral steroid therapy and steroid pulse therapy as the initial treatment for AIP. We studied the clinical course and image findings to estimate the utility of steroid pulse therapy for AIP, comparing it with oral steroid therapy. Laboratory and image findings were assessed retrospectively in 11 patients who received steroid pulse therapy, and the findings were compared to those in 10 patients who received conventional oral steroid therapy. Change in pancreatic size showed no significant difference between the therapies after 2 weeks of treatment. Significant improvement of lower bile duct strictures after 2 weeks of treatment and that of immunoglobulin values within 6 months were shown with both therapies. However, steroid pulse therapy showed significant improvement of γ-guanosine triphosphate (GTP) in 2 weeks and of alanine aminotransferase (ALT) in 2 and 8 weeks, compared with oral steroid therapy. Moreover, there was one patient in whom the lower bile duct stricture was not improved by oral steroid therapy, but it did show improvement with steroid pulse therapy. Initial steroid pulse therapy is a beneficial alternative to oral steroid therapy for the improvement of bile duct lesions. In future, the accumulation of a larger number of patients receiving steroid pulse therapy is needed, and prospective studies will be required.

  10. Telematics techniques for image based diagnosis, therapy planning and monitoring.

    Science.gov (United States)

    Bidaut, L M; Scherrer, J R

    1998-01-01

    This paper is intended to describe and illustrate some of the actual use of telematics related techniques together with modern biomedical imaging capabilities for helping in diagnosis, as well as for the planning and monitoring of therapy. To this end, most current imaging modalities are initially introduced. Then it is shown how telematics related techniques are necessary to improve the outcome of current image-based protocols. Such techniques allow data, means, or competencies--which may intrinsically be of a complementary nature or distributed at many different locations--to be integrated together and transcend the simple sum of individual expectations. Examples of actual implementations are given in the fields of radio-oncology, neurosurgery and orthopedics. To conclude, the papers and posters presented in the corresponding session of the MIE'97 symposium are summarized to provide further telematics references for the reader.

  11. Strategic level proton therapy patient admission planning: a Markov decision process modeling approach.

    Science.gov (United States)

    Gedik, Ridvan; Zhang, Shengfan; Rainwater, Chase

    2017-06-01

    A relatively new consideration in proton therapy planning is the requirement that the mix of patients treated from different categories satisfy desired mix percentages. Deviations from these percentages and their impacts on operational capabilities are of particular interest to healthcare planners. In this study, we investigate intelligent ways of admitting patients to a proton therapy facility that maximize the total expected number of treatment sessions (fractions) delivered to patients in a planning period with stochastic patient arrivals and penalize the deviation from the patient mix restrictions. We propose a Markov Decision Process (MDP) model that provides very useful insights in determining the best patient admission policies in the case of an unexpected opening in the facility (i.e., no-shows, appointment cancellations, etc.). In order to overcome the curse of dimensionality for larger and more realistic instances, we propose an aggregate MDP model that is able to approximate optimal patient admission policies using the worded weight aggregation technique. Our models are applicable to healthcare treatment facilities throughout the United States, but are motivated by collaboration with the University of Florida Proton Therapy Institute (UFPTI).

  12. Nuclear medicine for photodynamic therapy in cancer: Planning, monitoring and nuclear PDT.

    Science.gov (United States)

    Kharroubi Lakouas, Dris; Huglo, Damien; Mordon, Serge; Vermandel, Maximilien

    2017-06-01

    Photodynamic therapy (PDT) is a modality with promising results for the treatment of various cancers. PDT is increasingly included in the standard of care for different pathologies. This therapy relies on the effects of light delivered to photosensitized cells. At different stages of delivery, PDT requires imaging to plan, evaluate and monitor treatment. The contribution of molecular imaging in this context is important and continues to increase. In this article, we review the contribution of nuclear medicine imaging in oncology to PDT for planning and therapeutic monitoring purposes. Several solutions have been proposed to plan PDT from nuclear medicine imaging. For instance, photosensitizer biodistribution has been evaluated with a radiolabeled photosensitizer or with conventional radiopharmaceuticals on positron emission tomography. The effects of PDT delivery have also been explored with specific SPECT or PET radiopharmaceuticals to evaluate the effects on cells (apoptosis, necrosis, proliferation, metabolism) or vascular damage. Finally, the synergy between photosensitizers and radiopharmaceuticals has been studied considering the Cerenkov effect to activate photosensitized cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Response to planned treatment interruptions in HIV infection varies across childhood

    DEFF Research Database (Denmark)

    NN, NN; Valerius, Niels Henrik

    2010-01-01

    OBJECTIVE: To evaluate clinical, immunological and virological consequences of CD4-guided antiretroviral therapy (ART) planned treatment interruptions (PTIs) compared with continuous therapy in children with chronic HIV infection in the Paediatric European Network for Treatment of AIDS 11 trial....... DESIGN: This was a multicentre, 72-week, open, randomized, phase II trial. METHODS: One hundred and nine children with HIV-RNA below 50 copies/ml and CD4% of at least 30% (2-6 years) or at least 25% and CD4 cell count of at least 500 cells/microl (7-15 years) were randomized to continuous therapy (53......-term follow-up in Paediatric European Network for Treatment of AIDS 11 trial are ongoing. Further research into the role of treatment interruption in children is required, particularly, as guidelines now recommend early ART for all infected infants....

  14. [Ozone therapy and tamsulosin in the treatment of cystitis].

    Science.gov (United States)

    Smeliakov, V A; Borisov, V V

    2013-01-01

    Treatment of cystitis remains an urgent problem in urology due to its prevalence, physical and social disadaptation of patients, and not always satisfactory treatment results. The article presents the results of treatment of 40 women aged 41.5 +/- 12.4 years with chronic cystitis. 20 patients received ozone therapy, 20 patients--ozone therapy in combination with alpha-adrenoblocker tamsulosin. Effectiveness of the treatment was evaluated using clinical data, data of bladder diaries, IPSS score, and uroflowmetry data. Dynamics of all the parameters in patients treated with ozone therapy in combination with tamsulosin was significantly higher in comparison with that in patients treated with ozone therapy only. As a result of the treatment, increased urine flow rate was accompanied by an increase in urination. Combination therapy with the use of ozone therapy and tamsulosin can be successfully and safely used in the treatment of patients with cystitis.

  15. Treatment plan complexity metrics for predicting IMRT pre-treatment quality assurance results.

    Science.gov (United States)

    Crowe, S B; Kairn, T; Kenny, J; Knight, R T; Hill, B; Langton, C M; Trapp, J V

    2014-09-01

    The planning of IMRT treatments requires a compromise between dose conformity (complexity) and deliverability. This study investigates established and novel treatment complexity metrics for 122 IMRT beams from prostate treatment plans. The Treatment and Dose Assessor software was used to extract the necessary data from exported treatment plan files and calculate the metrics. For most of the metrics, there was strong overlap between the calculated values for plans that passed and failed their quality assurance (QA) tests. However, statistically significant variation between plans that passed and failed QA measurements was found for the established modulation index and for a novel metric describing the proportion of small apertures in each beam. The 'small aperture score' provided threshold values which successfully distinguished deliverable treatment plans from plans that did not pass QA, with a low false negative rate.

  16. Manpower Planning for Wastewater Treatment Plants.

    Science.gov (United States)

    Davies, J. Kenneth; And Others

    This document discusses the components necessary in the development of a forecasting process by which manpower needs can be determined and the development of action programs by which the projected needs may be satisfied. The primary focus of this manual is directed at that person in a state agency who has the responsibility for planning the…

  17. Antimicrobial photodynamic therapy treatment of chronic recurrent sinusitis biofilms.

    Science.gov (United States)

    Biel, Merrill A; Sievert, Chet; Usacheva, Marina; Teichert, Matthew; Balcom, Jim

    2011-01-01

    Chronic recurrent sinusitis (CRS) is an inflammatory disease of the facial sinuses and nasal passages that is defined as lasting longer than 12 weeks or occurring more than 4 times per year with symptoms usually lasting more than 20 days. The National Institute for Health Statistics estimates that CRS is one of the most common chronic conditions in the United States, affecting an estimated 37 million Americans. The potential etiologies of CRS include bacteria, viruses, allergies, fungi, superantigens, and microbial biofilms. In clinical practice there is a significant subpopulation of patients with CRS who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy, and prolonged antibiotic therapy. The reason for treatment failure is thought to be related to the destruction of the sinus mucociliary defense by the chronic sinus infection resulting in the development of secondary antibiotic-resistant microbial colonization of the sinuses and biofilm formation. Antimicrobial photodynamic therapy (aPDT) is a nonantibiotic broad-spectrum antimicrobial treatment that has been demonstrated to eradicate antibiotic-resistant bacteria and biofilms. The objective of this study was to demonstrate the effectiveness of a noninvasive aPDT treatment method of eradicating antibiotic resistant biofilms/microorganisms known to cause CRS in an in vitro model. Antibiotic-resistant planktonic bacteria and fungi and polymicrobial biofilms of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) were grown on silastic sheets and treated with a methylene blue photosensitizer and 670 nm non-thermal-activating light. Cultures of the planktonic microorganisms and biofilms were obtained before and after light treatment to determine efficacy of planktonic bacteria and biofilm reduction. The in vitro CRS planktonic microorganism and biofilm study demonstrated that aPDT reduced the CRS polymicrobial biofilm by >99.9% after a single

  18. Antimicrobial Photodynamic Therapy Treatment of Chronic Recurrent Sinusitis Biofilms

    Science.gov (United States)

    Biel, Merrill A.; Sievert, Chet; Usacheva, Marina; Teichert, Matthew; Balcom, Jim

    2011-01-01

    Background Chronic recurrent sinusitis (CRS) is an inflammatory disease of the facial sinuses and nasal passages that is defined as lasting longer than 12 weeks or occurring more than 4 times per year with symptoms usually lasting more than 20 days. The National Institute for Health Statistics estimates that CRS is one of the most common chronic conditions in the United States affecting an estimated 37 million Americans. The potential etiologies of CRS include bacteria, viruses, allergies, fungi, superantigens and microbial biofilms. In clinical practice there is a significant subpopulation of patients with CRS who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy and prolonged antibiotic therapy. The reason for treatment failure is thought to be related to the destruction of the sinus mucociliary defense by the chronic sinus infection resulting in the development of secondary antibiotic resistant microbial colonization of the sinuses and biofilm formation. Antimicrobial photodynamic therapy (aPDT) is a non-antibiotic broad spectrum antimicrobial treatment that has been demonstrated to eradicate antibiotic resistant bacteria and biofilms. Objective The objective of this study was to demonstrate the effectiveness of a non-invasive aPDT treatment method of eradicating antibiotic resistant biofilms/microorganisms known to cause CRS in an in vitro model. Methods Antibiotic resistant planktonic bacteria and fungi and polymicrobial biofilms of Pseudomonas aerugenosa and MRSA were grown on silastic sheets and treated with a methylene blue photosensitizer and 670nm non-thermal activating light. Cultures of the planktonic micoroorganisms and biofilms were obtained before and after light treatment to determine efficacy of planktonic baciteria and biofilm reduction. Results The in vitro CRS planktonic microorganism and biofilm study demonstrated that aPDT reduced the CRS polymicrobial biofilm by >99.9% after a single treatment

  19. Reoptimization of Intensity Modulated Proton Therapy Plans Based on Linear Energy Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Botas, Pablo [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Faculty of Physics, Ruprecht-Karls-Universität Heidelberg, Heidelberg (Germany); Giantsoudi, Drosoula; Gorissen, Bram L.; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2016-12-01

    Purpose: We describe a treatment plan optimization method for intensity modulated proton therapy (IMPT) that avoids high values of linear energy transfer (LET) in critical structures located within or near the target volume while limiting degradation of the best possible physical dose distribution. Methods and Materials: To allow fast optimization based on dose and LET, a GPU-based Monte Carlo code was extended to provide dose-averaged LET in addition to dose for all pencil beams. After optimizing an initial IMPT plan based on physical dose, a prioritized optimization scheme is used to modify the LET distribution while constraining the physical dose objectives to values close to the initial plan. The LET optimization step is performed based on objective functions evaluated for the product of LET and physical dose (LET×D). To first approximation, LET×D represents a measure of the additional biological dose that is caused by high LET. Results: The method is effective for treatments where serial critical structures with maximum dose constraints are located within or near the target. We report on 5 patients with intracranial tumors (high-grade meningiomas, base-of-skull chordomas, ependymomas) in whom the target volume overlaps with the brainstem and optic structures. In all cases, high LET×D in critical structures could be avoided while minimally compromising physical dose planning objectives. Conclusion: LET-based reoptimization of IMPT plans represents a pragmatic approach to bridge the gap between purely physical dose-based and relative biological effectiveness (RBE)-based planning. The method makes IMPT treatments safer by mitigating a potentially increased risk of side effects resulting from elevated RBE of proton beams near the end of range.

  20. A Clinical Concept for Interfractional Adaptive Radiation Therapy in the Treatment of Head and Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Alexandra D., E-mail: Alexandra.Jensen@med.uni-heidelberg.de [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Nill, Simeon [Department of Medical Physics, German Cancer Research Centre (DKFZ), Heidelberg (Germany); Huber, Peter E. [Clinical Co-Operation Unit Radiation Oncology, German Cancer Research Centre (DKFZ), Heidelberg (Germany); Bendl, Rolf [Department of Medical Physics, German Cancer Research Centre (DKFZ), Heidelberg (Germany); Debus, Juergen; Muenter, Marc W. [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany)

    2012-02-01

    Purpose: To present an approach to fast, interfractional adaptive RT in intensity-modulated radiation therapy (IMRT) of head and neck tumors in clinical routine. Ensuring adequate patient position throughout treatment proves challenging in high-precision RT despite elaborate immobilization. Because of weight loss, treatment plans must be adapted to account for requiring supportive therapy incl. feeding tube or parenteral nutrition without treatment breaks. Methods and Materials: In-room CT position checks are used to create adapted IMRT treatment plans by stereotactic correlation to the initial setup, and volumes are adapted to the new geometry. New IMRT treatment plans are prospectively created on the basis of position control scans using the initial optimization parameters in KonRad without requiring complete reoptimization and thus facilitating quick replanning in daily routine. Patients treated for squamous cell head and neck cancer (SCCHN) in 2006-2007 were evaluated as to necessity/number of replannings, weight loss, dose, and plan parameters. Results: Seventy-two patients with SCCHN received IMRT to the primary site and lymph nodes (median dose 70.4 Gy). All patients received concomitant chemotherapy requiring supportive therapy by feeding tube or parenteral nutrition. Median weight loss was 7.8 kg, median volume loss was approximately 7%. Fifteen of 72 patients required adaptation of their treatment plans at least once. Target coverage was improved by up to 10.7% (median dose). The increase of dose to spared parotid without replanning was 11.7%. Replanning including outlining and optimization was feasible within 2 hours for each patient, and treatment could be continued without any interruptions. Conclusion: To preserve high-quality dose application, treatment plans must be adapted to anatomical changes. Replanning based on position control scans therefore presents a practical approach in clinical routine. In the absence of clinically usable online

  1. (18) F-FDG PET/CT for planning external beam radiotherapy alters therapy in 11% of 581 patients

    DEFF Research Database (Denmark)

    Birk Christensen, Charlotte; Loft-Jakobsen, Annika; Munck Af Rosenschöld, Per

    2017-01-01

    BACKGROUND: (18) F-FDG PET/CT (FDG PET/CT) used in radiotherapy planning for extra-cerebral malignancy may reveal metastases to distant sites that may affect the choice of therapy. AIM: To investigate the role of FDG PET/CT on treatment strategy changes induced by the use of PET/CT as part...... of the radiotherapy planning. 'A major change of treatment strategy' was defined as either including more lesions in the gross tumour volume (GTV) distant from the primary tumour or a change in treatment modalities. METHODS: The study includes 581 consecutive patients who underwent an FDG PET/CT scan for radiotherapy...... planning in our institution in the year 2008. All PET/CT scans were performed with the patient in treatment position with the use of immobilization devices according to the intended radiotherapy treatment. All scans were evaluated by a nuclear medicine physician together with a radiologist to delineate PET...

  2. NCTPlan application for neutron capture therapy dosimetric planning at MEPhI nuclear research reactor.

    Science.gov (United States)

    Elyutina, A S; Kiger, W S; Portnov, A A

    2011-12-01

    The results of modeling of two therapeutic beams HEC-1 and HEC-4 at the NRNU "MEPhI" research nuclear reactor exploitable for preclinical treatments are reported. The exact models of the beams are constructed as an input to the NCTPlan code used for planning Neutron Capture Therapy (NCT) procedure. The computations are purposed to improve the accuracy of prediction of a dose absorbed in tissue with the account of all components of radiation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Proposed Site Treatment Plan (PSTP). STP reference document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-22

    The Department of Energy (DOE) is required by Section 3021(b) of the Resource Conservation and Recovery Act (RCRA), as amended by the Federal Facility Compliance Act (FFCAct), to prepare a plan describing the development of treatment capacities and technologies for treating mixed waste (hazardous/radioactive waste). DOE decided to prepare its site treatment plan in a three phased approach. The first phase, called the Conceptual Site Treatment Plan (CSTP), was issued in October 1993. At the Savannah River Site (SRS) the CSTP described mixed waste streams generated at SRS and listed treatment scenarios for each waste stream utilizing an onsite, offsite DOE, and offsite or onsite commercial or vendor treatment option. The CSTP is followed by the Draft Site Treatment Plan (DSTP), due to be issued in August 1994. The DSTP, the current activity., will narrow the options discussed in the CSTP to a preferred treatment option, if possible, and will include waste streams proposed to be shipped to SRS from other DOE facilities as well as waste streams SRS may send offsite for treatment. The SRS DSTP process has been designed to address treatment options for each of the site`s mixed waste streams. The SRS Proposed Site Treatment Plan (PSTP) is due to be issued in February 1995. The compliance order would be derived from the PSTP.

  4. 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.

  5. A simple DVH generation technique from various radiotherapy treatment planning systems for independent information system

    CERN Document Server

    Min, Byung Jun; Jeong, Il Sun; Lee, Hyebin

    2015-01-01

    In recent years, the use of PACS for radiation therapy has become the norm in hospital environment and has suggested for collecting data and management from different TPSs with DICOM objects. However, some TPS does not provide the DVH exportation with text or other format. In addition, plan review systems for various TPSs often allow DVH recalculation with different algorithms. These algorithms result in the inevitable discrepancy between the values obtained with the recalculation and those obtained with TPS itself. The purpose of this study was to develop a simple method for generating reproducible DVH values obtained from the TPSs. Treatment planning information including structures and delivered dose was exported by the DICOM format from planning systems. The supersampling and trilinear interpolation methods were employed to calculate DVH data from 35 treatment plans. The discrepancies between DVHs extracted from each TPS and the proposed calculation method were evaluated with respect to the supersampling ...

  6. [Hand Therapy in the Treatment of Patients with CRPS].

    Science.gov (United States)

    Körbler, C; Pfau, M; Becker, F; Koester, U; Werdin, F

    2015-06-01

    In the modern treatment of CRPS a multidisciplinary concept is firmly established (MMPT, multimodal pain therapy). Besides medical therapy and psychotherapy, physio- and occupational therapy count as basic treatment options. Although physio- and occupational therapy (in the following called hand therapy) are the most important basic treatments, the therapy is hardly standardised and there are few scientific investigations concerning their application. Therefore the purpose of this paper is to present the applied hand therapeutic techniques with regard to function/performance, application and effectiveness, and to derive a suitable treatment algorithm. The techniques used in hand therapy are presented and reviewed in regard to their effectiveness by means of a literature search. It turns out that exercise therapy, manual therapy, graded motor imaging, CO2 baths and occupational therapy have a proven benefit for the patients. Although for many of the treatments reliable evidence-based data are lacking a treatment algorithm was established but there is a strong need for further investigations concerning the therapeutic effectiveness in the treatment of CRPS. © Georg Thieme Verlag KG Stuttgart · New York.

  7. A planning study investigating dual-gated volumetric arc stereotactic treatment of primary renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Devereux, Thomas, E-mail: thomas.devereux@petermac.org [Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne (Australia); Pham, Daniel [Radiation Therapy Services, Peter MacCallum Cancer Centre, Melbourne (Australia); Kron, Tomas [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne (Australia); Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne (Australia); Foroudi, Farshad [Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne (Australia); Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne (Australia); Supple, Jeremy [School of Applied Sciences, Royal Melbourne Institute of Technology, Melbourne (Australia); Siva, Shankar [Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne (Australia); Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne (Australia)

    2015-04-01

    This is a planning study investigating the dosimetric advantages of gated volumetric-modulated arc therapy (VMAT) to the end-exhale and end-inhale breathing phases for patients undergoing stereotactic treatment of primary renal cell carcinoma. VMAT plans were developed from the end-inhale (VMATinh) and the end-exhale (VMATexh) phases of the breathing cycle as well as a VMAT plan and 3-dimensional conformal radiation therapy plan based on an internal target volume (ITV) (VMATitv). An additional VMAT plan was created by giving the respective gated VMAT plan a 50% weighting and summing the inhale and exhale plans together to create a summed gated plan. Dose to organs at risk (OARs) as well as comparison of intermediate and low-dose conformity was evaluated. There was no difference in the volume of healthy tissue receiving the prescribed dose for the planned target volume (PTV) (CI100%) for all the VMAT plans; however, the mean volume of healthy tissue receiving 50% of the prescribed dose for the PTV (CI50%) values were 4.7 (± 0.2), 4.6 (± 0.2), and 4.7 (± 0.6) for the VMATitv, VMATinh, and VMATexh plans, respectively. The VMAT plans based on the exhale and inhale breathing phases showed a 4.8% and 2.4% reduction in dose to 30 cm{sup 3} of the small bowel, respectively, compared with that of the ITV-based VMAT plan. The summed gated VMAT plans showed a 6.2% reduction in dose to 30 cm{sup 3} of the small bowel compared with that of the VMAT plans based on the ITV. Additionally, when compared with the inhale and the exhale VMAT plans, a 4% and 1.5%, respectively, reduction was observed. Gating VMAT was able to reduce the amount of prescribed, intermediate, and integral dose to healthy tissue when compared with VMAT plans based on an ITV. When summing the inhale and exhale plans together, dose to healthy tissue and OARs was optimized. However, gating VMAT plans would take longer to treat and is a factor that needs to be considered.

  8. A dose-volume-based tool for evaluating and ranking IMRT treatment plans.

    Science.gov (United States)

    Miften, Moyed M; Das, Shiva K; Su, Min; Marks, Lawrence B

    2004-01-01

    External beam radiotherapy is commonly used for patients with cancer. While tumor shrinkage and palliation are frequently achieved, local control and cure remain elusive for many cancers. With regard to local control, the fundamental problem is that radiotherapy-induced normal tissue injury limits the dose that can be delivered to the tumor. While intensity-modulated radiation therapy (IMRT) allows for the delivery of higher tumor doses and the sparing of proximal critical structures, multiple competing plans can be generated based on dosimetric and/or biological constraints that need to be considered/compared. In this work, an IMRT treatment plan evaluation and ranking tool, based on dosimetric criteria, is presented. The treatment plan with the highest uncomplicated target conformity index (TCI+) is ranked at the top. The TCI+ is a dose-volume-based index that considers both a target conformity index (TCI) and a normal tissue-sparing index (NTSI). TCI+ is designed to assist in the process of judging the merit of a clinical treatment plan. To demonstrate the utility of this tool, several competing lung and prostate IMRT treatment plans are compared. Results show that the plan with the highest TCI+ values accomplished the competing goals of tumor coverage and critical structures sparing best, among rival treatment plans for both treatment sites. The study demonstrates, first, that dose-volume-based indices, which summarize complex dose distributions through a single index, can be used to automatically select the optimal plan among competing plans, and second, that this dose-volume-based index may be appropriate for ranking IMRT dose distributions.

  9. Optimal partial-arcs in VMAT treatment planning

    CERN Document Server

    Wala, Jeremiah; Chen, Wei; Craft, David

    2012-01-01

    Purpose: To improve the delivery efficiency of VMAT by extending the recently published VMAT treatment planning algorithm vmerge to automatically generate optimal partial-arc plans. Methods and materials: A high-quality initial plan is created by solving a convex multicriteria optimization problem using 180 equi-spaced beams. This initial plan is used to form a set of dose constraints, and a set of partial-arc plans is created by searching the space of all possible partial-arc plans that satisfy these constraints. For each partial-arc, an iterative fluence map merging and sequencing algorithm (vmerge) is used to improve the delivery efficiency. Merging continues as long as the dose quality is maintained above a user-defined threshold. The final plan is selected as the partial arc with the lowest treatment time. The complete algorithm is called pmerge. Results: Partial-arc plans are created using pmerge for a lung, liver and prostate case, with final treatment times of 127, 245 and 147 seconds. Treatment times...

  10. SU-E-T-357: Semi-Automated Knowledge-Based Radiation Therapy (KBRT) Planning for Head-And-Neck Cancer (HNC): Can KBRT Plans Achieve Better Results Than Manual Planning?

    Energy Technology Data Exchange (ETDEWEB)

    Lutzky, C; Grzetic, S; Lo, J; Das, S [Duke University Medical Center, Durham, NC (United States)

    2014-06-01

    Purpose: Knowledge Based Radiation Therapy Treatment (KBRT) planning can be used to semi-automatically generate IMRT plans for new patients using constraints derived from previously manually-planned, geometrically similar patients. We investigate whether KBRT plans can achieve greater dose sparing than manual plans using optimized, organspecific constraint weighting factors. Methods: KBRT planning of HNC radiotherapy cases geometrically matched each new (query) case to one of the 105 clinically approved plans in our database. The dose distribution of the planned match was morphed to fit the querys geometry. Dose-volume constraints extracted from the morphed dose distribution were used to run the IMRT optimization with no user input. In the first version, all constraints were multiplied by a weighting factor of 0.7. The weighting factors were then systematically optimized (in order of OARs with increasing separation from the target) to maximize sparing to each OAR without compromising other OARs. The optimized, second version plans were compared against the first version plans and the clinically approved plans for 45 unilateral/bilateral target cases using the dose metrics: mean, median and maximum (brainstem and cord) doses. Results: Compared to the first version, the second version significantly reduced mean/median contralateral parotid doses (>2Gy) for bilateral cases. Other changes between the two versions were not clinically meaningful. Compared to the original clinical plans, both bilateral and unilateral plans in the second version had lower average dose metrics for 5 of the 6 OARs. Compared to the original plans, the second version achieved dose sparing that was at least as good for all OARs and better for the ipsilateral parotid (bilateral) and oral cavity (bilateral/unilateral). Differences in planning target volume coverage metrics were not clinically significant. Conclusion: HNC-KBRT planning generated IMRT plans with at least equivalent dose sparing to

  11. Gene Therapy Used in Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Thomas Wirth

    2014-04-01

    Full Text Available Cancer has been, from the beginning, a target of intense research for gene therapy approaches. Currently, more than 60% of all on-going clinical gene therapy trials worldwide are targeting cancer. Indeed, there is a clear unmet medical need for novel therapies. This is further urged by the fact that current conventional cancer therapies are frequently troubled by their toxicities. Different gene therapy strategies have been employed for cancer, such as pro-drug activating suicide gene therapy, anti-angiogenic gene therapy, oncolytic virotherapy, gene therapy-based immune modulation, correction/compensation of gene defects, genetic manipulation of apoptotic and tumor invasion pathways, antisense, and RNAi strategies. Cancer types, which have been targeted with gene therapy, include brain, lung, breast, pancreatic, liver, colorectal, prostate, bladder, head and neck, skin, ovarian, and renal cancer. Currently, two cancer gene therapy products have received market approval, both of which are in China. In addition, the stimulation of the host’s immune system, using gene therapeutic approaches, has gained vast interest. The intention of this review is to point out the most commonly viral and non-viral vectors and methods used in cancer gene therapy, as well as highlight some key results achieved in clinical trials.

  12. The influence of cephalometrics on orthodontic treatment planning

    NARCIS (Netherlands)

    Nijkamp, P.G.; Habets, L.L.M.H.; Aartman, I.H.A.; Zentner, A.

    2008-01-01

    SUMMARY Since its introduction, cephalometrics, i.e. cephalometric radiography and analysis, has been used for orthodontic treatment planning. However, the effectiveness of this diagnostic method remains questionable. A randomized crossover study was designed to assess the infl uence of

  13. 300 Area waste acid treatment system closure plan. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This section provides a description of the Hanford Site, identifies the proposed method of 300 Area Waste Acid Treatment System (WATS) closure, and briefly summarizes the contents of each chapter of this plan.

  14. "SABER": A new software tool for radiotherapy treatment plan evaluation.

    Science.gov (United States)

    Zhao, Bo; Joiner, Michael C; Orton, Colin G; Burmeister, Jay

    2010-11-01

    Both spatial and biological information are necessary in order to perform true optimization of a treatment plan and for predicting clinical outcome. The goal of this work is to develop an enhanced treatment plan evaluation tool which incorporates biological parameters and retains spatial dose information. A software system is developed which provides biological plan evaluation with a novel combination of features. It incorporates hyper-radiosensitivity using the induced-repair model and applies the new concept of dose convolution filter (DCF) to simulate dose wash-out effects due to cell migration, bystander effect, and/or tissue motion during treatment. Further, the concept of spatial DVH (sDVH) is introduced to evaluate and potentially optimize the spatial dose distribution in the target volume. Finally, generalized equivalent uniform dose is derived from both the physical dose distribution (gEUD) and the distribution of equivalent dose in 2 Gy fractions (gEUD2) and the software provides three separate models for calculation of tumor control probability (TCP), normal tissue complication probability (NTCP), and probability of uncomplicated tumor control (P+). TCP, NTCP, and P+ are provided as a function of prescribed dose and multivariable TCP, NTCP, and P+ plots are provided to illustrate the dependence on individual parameters used to calculate these quantities. Ten plans from two clinical treatment sites are selected to test the three calculation models provided by this software. By retaining both spatial and biological information about the dose distribution, the software is able to distinguish features of radiotherapy treatment plans not discernible using commercial systems. Plans that have similar DVHs may have different spatial and biological characteristics and the application of novel tools such as sDVH and DCF within the software may substantially change the apparent plan quality or predicted plan metrics such as TCP and NTCP. For the cases examined

  15. [Clinical treatment of occlusion in implant therapy].

    Science.gov (United States)

    Nakamura, Kimio

    2008-01-01

    A firmly established theory on occlusion, even with natural teeth, has been all but absent throughout history. it is even more difficult to find and evidence-based concept of occlusion for the relatively new field of implantology. Since i harbored doubts on initial gnathological theories of occlusion decades ago, my work in treating occlusion in patients with temporomandibular arthrosis has brought me to the realization that the diagnosis and adjustment of the alignment or misalignment of the light guide tapping position ( LGTP ) and clenching position (CLP) in the stable condylar position are important focal points for clinical occlusion. I have therefore striven for the seamless incorporation of the prosthodontic techniques of maintaining, correcting, and restoring occlusion into my day to day clinical practice, which includes periodontal treatment and orthodontics. Implantology has now been added to this context, and i feel there is no need to take a drastically different approach to creating and adjusting implant occlusion. I will present actual case reports and post operative observations of patients who received implant therapy in our clinic.

  16. Cluttering Treatment: Theoretical Considerations and Intervention Planning

    NARCIS (Netherlands)

    Dr. Yvonne van Zaalen; Isabella K. Reichel

    2014-01-01

    This article presents a variety of treatment approaches based on an understanding of four components of communication, and describes cluttering intervention focusing on problem identification, speech rate reduction, appropriate pausing, appropriate monitoring, and addressing story narrating skills.

  17. Treatment planning of electroporation-based medical interventions: electrochemotherapy, gene electrotransfer and irreversible electroporation

    Science.gov (United States)

    Zupanic, Anze; Kos, Bor; Miklavcic, Damijan

    2012-09-01

    In recent years, cancer electrochemotherapy (ECT), gene electrotransfer for gene therapy and DNA vaccination (GET) and tissue ablation with irreversible electroporation (IRE) have all entered clinical practice. We present a method for a personalized treatment planning procedure for ECT, GET and IRE, based on medical image analysis, numerical modelling of electroporation and optimization with the genetic algorithm, and several visualization tools for treatment plan assessment. Each treatment plan provides the attending physician with optimal positions of electrodes in the body and electric pulse parameters for optimal electroporation of the target tissues. For the studied case of a deep-seated tumour, the optimal treatment plans for ECT and IRE require at least two electrodes to be inserted into the target tissue, thus lowering the necessary voltage for electroporation and limiting damage to the surrounding healthy tissue. In GET, it is necessary to place the electrodes outside the target tissue to prevent damage to target cells intended to express the transfected genes. The presented treatment planning procedure is a valuable tool for clinical and experimental use and evaluation of electroporation-based treatments.

  18. Treatment planning of electroporation-based medical interventions: electrochemotherapy, gene electrotransfer and irreversible electroporation.

    Science.gov (United States)

    Zupanic, Anze; Kos, Bor; Miklavcic, Damijan

    2012-09-07

    In recent years, cancer electrochemotherapy (ECT), gene electrotransfer for gene therapy and DNA vaccination (GET) and tissue ablation with irreversible electroporation (IRE) have all entered clinical practice. We present a method for a personalized treatment planning procedure for ECT, GET and IRE, based on medical image analysis, numerical modelling of electroporation and optimization with the genetic algorithm, and several visualization tools for treatment plan assessment. Each treatment plan provides the attending physician with optimal positions of electrodes in the body and electric pulse parameters for optimal electroporation of the target tissues. For the studied case of a deep-seated tumour, the optimal treatment plans for ECT and IRE require at least two electrodes to be inserted into the target tissue, thus lowering the necessary voltage for electroporation and limiting damage to the surrounding healthy tissue. In GET, it is necessary to place the electrodes outside the target tissue to prevent damage to target cells intended to express the transfected genes. The presented treatment planning procedure is a valuable tool for clinical and experimental use and evaluation of electroporation-based treatments.

  19. Implementation of adaptive radiation therapy for urinary bladder carcinoma - Imaging, planning and image guidance

    Energy Technology Data Exchange (ETDEWEB)

    Tuomikoski, Laura; Collan, Juhani; Keyrilaeinen, Jani; Saarilahti, Kauko; Tenhunen, Mikko [Dept. of Oncology, Helsinki Univ. Central Hospital, Helsinki (Finland)], e-mail: laura.tuomikoski@hus.fi; Korhonen, Juha [Dept. of Oncology, Helsinki Univ. Central Hospital, Helsinki (Finland); Clinical Research Inst. Helsinki Univ. Central Hospital Ltd, Helsinki (Finland); Visapaeae, Harri [Dept. of Oncology, Helsinki Univ. Central Hospital, Helsinki (Finland); Dept. of Urology, Helsinki Univ. Central Hospital, Helsinki (Finland); Sairanen, Jukka [Dept. of Urology, Helsinki Univ. Central Hospital, Helsinki (Finland)

    2013-10-15

    Background: Adaptive radiation therapy (ART) for urinary bladder cancer has emerged as a promising alternative to conventional RT with potential to minimize radiation-induced toxicity to healthy tissues. In this work we have studied bladder volume variations and their effect on healthy bladder dose sparing and intra fractional margins, in order to refine our ART strategy. Material and methods: An online ART treatment strategy was followed for five patients with urinary bladder cancer with the tumors demarcated using Lipiodol. A library of 3-4 predefined treatment plans for each patient was created based on four successive computed tomography (CT) scans. Cone beam CT (CBCT) images were acquired before each treatment fraction and after the treatment at least weekly. In partial bladder treatment the sparing of the healthy part of the bladder was investigated. The bladder wall displacements due to bladder filling were determined in three orthogonal directions (CC, AP, DEX-SIN) using the treatment planning CT scans. An ellipsoidal model was applied in order to find the theoretical maximum values for the bladder wall displacements. Moreover, the actual bladder filling rate during treatment was evaluated using the CBCT images. Results: In partial bladder treatment the volume of the bladder receiving high absorbed doses was generally smaller with a full than empty bladder. The estimation of the bladder volume and the upper limit for the intra fractional movement of the bladder wall could be represented with an ellipsoidal model with a reasonable accuracy. Observed maximum growth of bladder dimensions was less than 10 mm in all three orthogonal directions during 15 minute interval. Conclusion: The use of Lipiodol contrast agent enables partial bladder treatment with reduced irradiation of the healthy bladder volume. The ellipsoidal bladder model can be used for the estimation of the bladder volume changes and the upper limit of the bladder wall movement during the treatment

  20. Orthodontic therapy in complex treatment of patiens with severe periodontitis

    Directory of Open Access Journals (Sweden)

    Hatskevich G.A.

    2011-03-01

    Full Text Available Contemporary orthodontic treatment require a complicity not only orthodontist, but other dental specialist. Most important it's in cases with occlusal deformation and accompanying periodontitis. In article describe the practical plan of difficult cases treatment

  1. Consideration of treatment fidelity to improve manual therapy research.

    Science.gov (United States)

    Karas, Steve; Plankis, Laura

    2016-09-01

    The purpose of this paper was to define treatment fidelity, review its use in health care research and suggest how it may be utilized in manual therapy research to improve the reliability and validity of the literature. We offer an outline and a table of how manual therapy research may benefit from the concept of treatment fidelity. While treatment fidelity is a newer concept, and has not been integrated into Physical Therapy or Manual Therapy research, when utilized, it can have positive effects on the reliability and validity of the techniques we evaluate.

  2. Radiation Therapy Planning for Early-Stage Hodgkin Lymphoma: Experience of the International Lymphoma Radiation Oncology Group

    Energy Technology Data Exchange (ETDEWEB)

    Maraldo, Maja V., E-mail: dra.maraldo@gmail.com [Departments of Clinical Oncology and Hematology, Rigshospitalet, University of Copenhagen (Denmark); Dabaja, Bouthaina S. [Department of Radiation Oncology, MD Anderson Cancer Center, Texas (United States); Filippi, Andrea R. [Department of Oncology, University of Torino School of Medicine, Torino (Italy); Illidge, Tim [Department of Oncology, Christie Hospital, Manchester (United Kingdom); Tsang, Richard [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Ricardi, Umberto [Department of Oncology, University of Torino School of Medicine, Torino (Italy); Petersen, Peter M.; Schut, Deborah A. [Departments of Clinical Oncology and Hematology, Rigshospitalet, University of Copenhagen (Denmark); Garcia, John [Department of Radiation Oncology, MD Anderson Cancer Center, Texas (United States); Headley, Jayne [Department of Oncology, Christie Hospital, Manchester (United Kingdom); Parent, Amy; Guibord, Benoit [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Ragona, Riccardo [Department of Oncology, University of Torino School of Medicine, Torino (Italy); Specht, Lena [Departments of Clinical Oncology and Hematology, Rigshospitalet, University of Copenhagen (Denmark)

    2015-05-01

    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, 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 30.6 Gy. A postchemotherapy computed tomography scan with precontoured clinical target volume (CTV) and OARs was provided for each patient. The treatment technique and planning methods were chosen according to each center's best practice in 2013. Results: Seven patients had mediastinal disease, 2 had 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-dimensional conformal RT (2-4 fields). The variations in CTV-to-planning target volume margins (5-15 mm), maximum tolerated dose (31.4-40 Gy), and plan conformity (conformity index 0-3.6) were significant. However, estimated doses to OARs were comparable between centers for each patient. Conclusions: RT planning for HL is challenging because of the heterogeneity in size and location of disease and, additionally, to the variation in choice of treatment techniques and field arrangements. Adopting ILROG guidelines and implementing universal dose objectives could further standardize treatment techniques and contribute to lowering the dose to the surrounding OARs.

  3. Radiation therapy planning for early-stage Hodgkin lymphoma: experience of the International Lymphoma Radiation Oncology Group.

    Science.gov (United States)

    Maraldo, Maja V; Dabaja, Bouthaina S; Filippi, Andrea R; Illidge, Tim; Tsang, Richard; Ricardi, Umberto; Petersen, Peter M; Schut, Deborah A; Garcia, John; Headley, Jayne; Parent, Amy; Guibord, Benoit; Ragona, Riccardo; Specht, Lena

    2015-05-01

    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, planning parameters, and estimated doses to the critical organs at risk (OARs). 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 30.6 Gy. A postchemotherapy computed tomography scan with precontoured clinical target volume (CTV) and OARs was provided for each patient. The treatment technique and planning methods were chosen according to each center's best practice in 2013. Seven patients had mediastinal disease, 2 had 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-dimensional conformal RT (2-4 fields). The variations in CTV-to-planning target volume margins (5-15 mm), maximum tolerated dose (31.4-40 Gy), and plan conformity (conformity index 0-3.6) were significant. However, estimated doses to OARs were comparable between centers for each patient. RT planning for HL is challenging because of the heterogeneity in size and location of disease and, additionally, to the variation in choice of treatment techniques and field arrangements. Adopting ILROG guidelines and implementing universal dose objectives could further standardize treatment techniques and contribute to lowering the dose to the surrounding OARs. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. 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

  5. Ozone Therapy in Treatment of Female Infertility

    OpenAIRE

    Maradi A. Burduli

    2015-01-01

    Ozone therapy and physiotherapy have been successfully used in obstetric practice. The paper summarizes the results of studies on the use of ozone therapy in the postoperative rehabilitation of gynecological patients operated on for female infertility of various origins. Biomechanisms systemic impact methods of ozone therapy on the human body to meet the requirements of the tactics of the impact on the etiopathogenic mechanisms of chronic inflammatory diseases of the pelvic organs and their c...

  6. Stereotactic body radiation therapy planning with duodenal sparing using volumetric-modulated arc therapy vs intensity-modulated radiation therapy in locally advanced pancreatic cancer: A dosimetric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rachit; Wild, Aaron T.; Ziegler, Mark A.; Hooker, Ted K.; Dah, Samson D.; Tran, Phuoc T.; Kang, Jun; Smith, Koren; Zeng, Jing [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States); Pawlik, Timothy M. [Department of Surgery, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tryggestad, Erik [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States); Ford, Eric [Department of Radiation Oncology, Fred Hutchinson Cancer Center, University of Washington, Seattle, WA (United States); Herman, Joseph M., E-mail: jherma15@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 401N. Broadway, Weinberg Suite 1440, Baltimore, MD 21231 (United States)

    2013-10-01

    Stereotactic body radiation therapy (SBRT) achieves excellent local control for locally advanced pancreatic cancer (LAPC), but may increase late duodenal toxicity. Volumetric-modulated arc therapy (VMAT) delivers intensity-modulated radiation therapy (IMRT) with a rotating gantry rather than multiple fixed beams. This study dosimetrically evaluates the feasibility of implementing duodenal constraints for SBRT using VMAT vs IMRT. Non–duodenal sparing (NS) and duodenal-sparing (DS) VMAT and IMRT plans delivering 25 Gy in 1 fraction were generated for 15 patients with LAPC. DS plans were constrained to duodenal D{sub max} of<30 Gy at any point. VMAT used 1 360° coplanar arc with 4° spacing between control points, whereas IMRT used 9 coplanar beams with fixed gantry positions at 40° angles. Dosimetric parameters for target volumes and organs at risk were compared for DS planning vs NS planning and VMAT vs IMRT using paired-sample Wilcoxon signed rank tests. Both DS VMAT and DS IMRT achieved significantly reduced duodenal D{sub mean}, D{sub max}, D{sub 1cc}, D{sub 4%}, and V{sub 20} {sub Gy} compared with NS plans (all p≤0.002). DS constraints compromised target coverage for IMRT as demonstrated by reduced V{sub 95%} (p = 0.01) and D{sub mean} (p = 0.02), but not for VMAT. DS constraints resulted in increased dose to right kidney, spinal cord, stomach, and liver for VMAT. Direct comparison of DS VMAT and DS IMRT revealed that VMAT was superior in sparing the left kidney (p<0.001) and the spinal cord (p<0.001), whereas IMRT was superior in sparing the stomach (p = 0.05) and the liver (p = 0.003). DS VMAT required 21% fewer monitor units (p<0.001) and delivered treatment 2.4 minutes faster (p<0.001) than DS IMRT. Implementing DS constraints during SBRT planning for LAPC can significantly reduce duodenal point or volumetric dose parameters for both VMAT and IMRT. The primary consequence of implementing DS constraints for VMAT is increased dose to other organs at

  7. 300 Area waste acid treatment system closure plan

    Energy Technology Data Exchange (ETDEWEB)

    LUKE, S.N.

    1999-05-17

    The Hanford Facility Dangerous Waste Permit Application is considered to be a single application organized into a General Information Portion (document number DOERL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion includes closure plan documentation submitted for individual, treatment, storage, and/or disposal units undergoing closure, such as the 300 Area Waste Acid Treatment System. Documentation contained in the General Information Portion is broader in nature and could be used by multiple treatment, storage, and/or disposal units (e.g., the glossary provided in the General Information Portion). Whenever appropriate, 300 Area Waste Acid Treatment System documentation makes cross-reference to the General Information Portion, rather than duplicating text. This 300 Area Waste Acid Treatment System Closure Plan (Revision 2) includes a Hanford Facility Dangerous Waste Permit Application, Part A, Form 3. Information provided in this closure plan is current as of April 1999.

  8. Sodium-Bearing Waste Treatment, Applied Technology Plan

    Energy Technology Data Exchange (ETDEWEB)

    Lance Lauerhass; Vince C. Maio; S. Kenneth Merrill; Arlin L. Olson; Keith J. Perry

    2003-06-01

    Settlement Agreement between the Department of Energy and the State of Idaho mandates treatment of sodium-bearing waste at the Idaho Nuclear Technology and Engineering Center within the Idaho National Engineering and Environmental Laboratory. One of the requirements of the Settlement Agreement is to complete treatment of sodium-bearing waste by December 31, 2012. Applied technology activities are required to provide the data necessary to complete conceptual design of four identified alternative processes and to select the preferred alternative. To provide a technically defensible path forward for the selection of a treatment process and for the collection of needed data, an applied technology plan is required. This document presents that plan, identifying key elements of the decision process and the steps necessary to obtain the required data in support of both the decision and the conceptual design. The Sodium-Bearing Waste Treatment Applied Technology Plan has been prepared to provide a description/roadmap of the treatment alternative selection process. The plan details the results of risk analyzes and the resulting prioritized uncertainties. It presents a high-level flow diagram governing the technology decision process, as well as detailed roadmaps for each technology. The roadmaps describe the technical steps necessary in obtaining data to quantify and reduce the technical uncertainties associated with each alternative treatment process. This plan also describes the final products that will be delivered to the Department of Energy Idaho Operations Office in support of the office's selection of the final treatment technology.

  9. Using discrete-event simulation in strategic capacity planning for an outpatient physical therapy service.

    Science.gov (United States)

    Rau, Chi-Lun; Tsai, Pei-Fang Jennifer; Liang, Sheau-Farn Max; Tan, Jhih-Cian; Syu, Hong-Cheng; Jheng, Yue-Ling; Ciou, Ting-Syuan; Jaw, Fu-Shan

    2013-12-01

    This study uses a simulation model as a tool for strategic capacity planning for an outpatient physical therapy clinic in Taipei, Taiwan. The clinic provides a wide range of physical treatments, with 6 full-time therapists in each session. We constructed a discrete-event simulation model to study the dynamics of patient mixes with realistic treatment plans, and to estimate the practical capacity of the physical therapy room. The changes in time-related and space-related performance measurements were used to evaluate the impact of various strategies on the capacity of the clinic. The simulation results confirmed that the clinic is extremely patient-oriented, with a bottleneck occurring at the traction units for Intermittent Pelvic Traction (IPT), with usage at 58.9 %. Sensitivity analysis showed that attending to more patients would significantly increase the number of patients staying for overtime sessions. We found that pooling the therapists produced beneficial results. The average waiting time per patient could be reduced by 45 % when we pooled 2 therapists. We found that treating up to 12 new patients per session had no significantly negative impact on returning patients. Moreover, we found that the average waiting time for new patients decreased if they were given priority over returning patients when called by the therapists.

  10. Radiobiologically based treatment plan evaluation for prostate seed implants

    Directory of Open Access Journals (Sweden)

    Sotirios Stathakis

    2011-07-01

    Full Text Available Purpose: Accurate prostate low dose-rate brachytherapy treatment plan evaluation is important for future care decisions. Presently, an evaluation is based on dosimetric quantifiers for the tumor and organs at risk. However, these do not account for effects of varying dose-rate, tumor repopulation and other biological effects. In this work, incorporation of the biological response is used to obtain more clinically relevant treatment plan evaluation.Material and methods: Eleven patients were evaluated. Each patient received a 145 Gy implant. Iodine-125 seeds were used and the treatment plans were created on the Prowess system. Based on CT images the post-implant plan was created. In the post-plan, the tumor, urethra, bladder and rectum were contoured. The biologically effective dose was used to determine the tumor control probability and the normal tissue complication probabilities for the urethra, bladder, rectum and surrounding tissue. Results: The average tumor control probability and complication probabilities for the urethra, bladder, rectum and surrounding tissue were 99%, 29%, 0%, 12% and 6%, respectively. These measures provide a simpler means for evaluation and since they include radiobiological factors, they provide more reliable estimation of the treatment outcome. Conclusions: The goal of this work was to create more clinically relevant prostate seed-implant evaluation by incorporating radiobiological measures. This resulted in a simpler descriptor of treatment plan quality and was consistent with patient outcomes.

  11. Radiobiologically based treatment plan evaluation for prostate seed implants.

    Science.gov (United States)

    Knaup, Courtney; Mavroidis, Panayiotis; Esquivel, Carlos; Baltas, Dimos; Stathakis, Sotirios; Swanson, Gregory; Papanikolaou, Nikos

    2011-06-01

    Accurate prostate low dose-rate brachytherapy treatment plan evaluation is important for future care decisions. Presently, an evaluation is based on dosimetric quantifiers for the tumor and organs at risk. However, these do not account for effects of varying dose-rate, tumor repopulation and other biological effects. In this work, incorporation of the biological response is used to obtain more clinically relevant treatment plan evaluation. Eleven patients were evaluated. Each patient received a 145 Gy implant. Iodine-125 seeds were used and the treatment plans were created on the Prowess system. Based on CT images the post-implant plan was created. In the post-plan, the tumor, urethra, bladder and rectum were contoured. The biologically effective dose was used to determine the tumor control probability and the normal tissue complication probabilities for the urethra, bladder, rectum and surrounding tissue. The average tumor control probability and complication probabilities for the urethra, bladder, rectum and surrounding tissue were 99%, 29%, 0%, 12% and 6%, respectively. These measures provide a simpler means for evaluation and since they include radiobiological factors, they provide more reliable estimation of the treatment outcome. The goal of this work was to create more clinically relevant prostate seed-implant evaluation by incorporating radiobiological measures. This resulted in a simpler descriptor of treatment plan quality and was consistent with patient outcomes.

  12. The NUKDOS software for treatment planning in molecular radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kletting, Peter; Schimmel, Sebastian [Univ. Ulm (Germany). Klinik fuer Nuklearmedizin; Haenscheid, Heribert; Fernandez, Maria; Lassmann, Michael [Univ. Wuerzburg (Germany). Klinik fuer Nuklearmedizin; Luster, Markus [Univ. Marburg (Germany). Klinik fuer Nuklearmedizin; Nosske, Dietmar [Bundesamt fuer Strahlenschutz, Fachbereich Strahlenschutz und Gesundheit, Oberschleissheim (Germany); Glatting, Gerhard [Heidelberg Univ., Medical Radiation Physics/Radiation Protection, Mannheim (Germany)

    2015-07-01

    The aim of this work was the development of a software tool for treatment planning prior to molecular radiotherapy, which comprises all functionality to objectively determine the activity to administer and the pertaining absorbed doses (including the corresponding error) based on a series of gamma camera images and one SPECT/CT or probe data. NUKDOS was developed in MATLAB. The workflow is based on the MIRD formalism For determination of the tissue or organ pharmacokinetics, gamma camera images as well as probe, urine, serum and blood activity data can be processed. To estimate the time-integrated activity coefficients (TIAC), sums of exponentials are fitted to the time activity data and integrated analytically. To obtain the TIAC on the voxel level, the voxel activity distribution from the quantitative 3D SPECT/CT (or PET/CT) is used for scaling and weighting the TIAC derived from the 2D organ data. The voxel S-values are automatically calculated based on the voxel-size of the image and the therapeutic nuclide ({sup 90}Y, {sup 131}I or {sup 177}Lu). The absorbed dose coefficients are computed by convolution of the voxel TIAC and the voxel S-values. The activity to administer and the pertaining absorbed doses are determined by entering the absorbed dose for the organ at risk. The overall error of the calculated absorbed doses is determined by Gaussian error propagation. NUKDOS was tested for the operation systems Windows {sup registered} 7 (64 Bit) and 8 (64 Bit). The results of each working step were compared to commercially available (SAAMII, OLINDA/EXM) and in-house (UlmDOS) software. The application of the software is demonstrated using examples form peptide receptor radionuclide therapy (PRRT) and from radioiodine therapy of benign thyroid diseases. For the example from PRRT, the calculated activity to administer differed by 4% comparing NUKDOS and the final result using UlmDos, SAAMII and OLINDA/EXM sequentially. The absorbed dose for the spleen and tumour

  13. Simulation techniques in hyperthermia treatment planning

    NARCIS (Netherlands)

    M.M. Paulides (Maarten); J.C. Stauffer; E. Neufeld; P.F. MacCarini (Paolo); A. Kyriakou (Adamos); R.A.M. Canters (Richard); S. Diederich (Sven); J. Bakker (Jan); G.C. van Rhoon (Gerard)

    2013-01-01

    textabstractClinical trials have shown that hyperthermia (HT), i.e. an increase of tissue temperature to 39-44 °C, significantly enhance radiotherapy and chemotherapy effectiveness [1]. Driven by the developments in computational techniques and computing power, personalised hyperthermia treatment

  14. FoCa: a modular treatment planning system for proton radiotherapy with research and educational purposes

    Science.gov (United States)

    Sánchez-Parcerisa, D.; Kondrla, M.; Shaindlin, A.; Carabe, A.

    2014-12-01

    FoCa is an in-house modular treatment planning system, developed entirely in MATLAB, which includes forward dose calculation of proton radiotherapy plans in both active and passive modalities as well as a generic optimization suite for inverse treatment planning. The software has a dual education and research purpose. From the educational point of view, it can be an invaluable teaching tool for educating medical physicists, showing the insights of a treatment planning system from a well-known and widely accessible software platform. From the research point of view, its current and potential uses range from the fast calculation of any physical, radiobiological or clinical quantity in a patient CT geometry, to the development of new treatment modalities not yet available in commercial treatment planning systems. The physical models in FoCa were compared with the commissioning data from our institution and show an excellent agreement in depth dose distributions and longitudinal and transversal fluence profiles for both passive scattering and active scanning modalities. 3D dose distributions in phantom and patient geometries were compared with a commercial treatment planning system, yielding a gamma-index pass rate of above 94% (using FoCa’s most accurate algorithm) for all cases considered. Finally, the inverse treatment planning suite was used to produce the first prototype of intensity-modulated, passive-scattered proton therapy, using 13 passive scattering proton fields and multi-leaf modulation to produce a concave dose distribution on a cylindrical solid water phantom without any field-specific compensator.

  15. Music therapy as a non-pharmacological treatment for epilepsy.

    Science.gov (United States)

    Liao, Huan; Jiang, Guohui; Wang, Xuefeng

    2015-01-01

    Epilepsy is one of the most common neurological diseases. Currently, the primary methods of treatment include pharmacological and surgical treatment. However, approximately one-third of patients exhibit refractory epilepsy. Therefore, a novel approach to epilepsy treatment is necessary. Several studies have confirmed that music therapy can be effective at reducing seizures and epileptiform discharges, thus providing a new option for clinicians in the treatment of epilepsy. Although the underlying mechanism of music therapy is unknown, it may be related to resonance, mirror neurons, dopamine pathways and parasympathetic activation. Large sample, multicenter, randomized double-blind and more effectively designed studies are needed for future music therapy studies.

  16. Safety and Efficacy of Pazopanib Therapy Prior to Planned Nephrectomy in Metastatic Clear Cell Renal Cancer.

    Science.gov (United States)

    Powles, Thomas; Sarwar, Naveed; Stockdale, Andrew; Sarker, Shah-Jalal; Boleti, Ekaterini; Protheroe, Andrew; Jones, Robert; Chowdhury, Simon; Peters, John; Oades, Grenville; O'Brien, Tim; Sullivan, Mark; Aitchison, Michael; Beltran, Luis; Worth, Daniel; Smith, Kate; Michel, Constance; Trevisan, Giorgia; Harvey-Jones, Elizabeth; Wimalasingham, Akhila; Sahdev, Anju; Ackerman, Charlotte; Crabb, Simon

    2016-10-01

    The role of cytoreductive nephrectomy in patients with metastatic renal cancer in the era of targeted therapy is uncertain. To establish the safety and efficacy of upfront pazopanib therapy prior to cytoreductive nephrectomy in previously untreated patients with metastatic clear cell renal cancer. Single-arm phase 2 study of 104 previously untreated patients with metastatic clear cell renal cancer recruited between June 2008 and October 2012 at cancer treatment centers with access to nephrectomy services. The minimum follow-up was 30 months. Patients received 12 to 14 weeks of preoperative pazopanib therapy prior to planned cytoreductive nephrectomy and continued pazopanib therapy after surgery. Treatment was stopped at disease progression. The primary end point was clinical benefit (using Response Evaluation Criteria in Solid Tumors, version 1.1) prior to surgery (at 12-14 weeks). Secondary end points included surgical complications, progression-free survival (PFS), overall survival (OS), and biomarker analysis. Of 104 patients recruited, 100 patients were assessable for clinical benefit prior to planned nephrectomy; 80 of 104 (76.9%) were men; median [interquartile range] age, 64 [56-71] years). Overall, 84 of 100 (84% [95% CI, 75%-91%]) gained clinical benefit before planned nephrectomy. The median reduction in the size of the primary tumor was 14.4% (interquartile range, 1.4%-21.1%). No patients were unable to undergo surgery as a result of local progression of disease. Nephrectomy was performed in 63 (61%) of patients; 14 (22%) reported surgical complications. The 2 most common reasons for not undergoing surgery were progression of disease (n = 13) and patient choice (n = 9). There was 1 postoperative surgical death. The median PFS and OS for the whole cohort were 7.1 (95% CI, 6.0-9.2) and 22.7 (95% CI, 14.3-not estimable) months, respectively. Patients with MSKCC poor-risk disease or progressive disease prior to surgery had a poor outcome (median OS

  17. Solid Mesh Registration for Radiotherapy Treatment Planning

    DEFF Research Database (Denmark)

    Noe, Karsten Østergaard; Sørensen, Thomas Sangild

    2010-01-01

    We present an algorithm for solid organ registration of pre-segmented data represented as tetrahedral meshes. Registration of the organ surface is driven by force terms based on a distance field representation of the source and reference shapes. Registration of internal morphology is achieved usi...... to complete. The proposed method has many potential uses in image guided radiotherapy (IGRT) which relies on registration to account for organ deformation between treatment sessions....

  18. Dental treatment planning and management for the mouth cancer patient.

    Science.gov (United States)

    Joshi, Vinod K

    2010-06-01

    The need to deliver cancer treatment promptly often requires modification of ideal dental treatment plans. Treatment planning and preventive care is crucial and needs to be done before radiotherapy in order to avoid complications such as osteoradionecrosis. Rapid delivery of this dental care can only be achieved if oral care is given adequate priority in the patient care pathway. Few cancer centres have the resources to provide comprehensive dental care and thus, in most circumstances, this care has to be provided by the patient's dentist and dental care professional, with advice from the local dental oncology specialist team. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. SU-E-T-502: Initial Results of a Comparison of Treatment Plans Produced From Automated Prioritized Planning Method and a Commercial Treatment Planning System

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, P; Chen, Y [Memorial Sloan Kettering Cancer Center, New York, NY (United States); Hong, L; Apte, A; Yang, J; Mechalakos, J; Mageras, G; Hunt, M; Deasy, J [Washington University in St. Louis (United States)

    2015-06-15

    Purpose We developed an automated treatment planning system based on a hierarchical goal programming approach. To demonstrate the feasibility of our method, we report the comparison of prostate treatment plans produced from the automated treatment planning system with those produced by a commercial treatment planning system. Methods In our approach, we prioritized the goals of the optimization, and solved one goal at a time. The purpose of prioritization is to ensure that higher priority dose-volume planning goals are not sacrificed to improve lower priority goals. The algorithm has four steps. The first step optimizes dose to the target structures, while sparing key sensitive organs from radiation. In the second step, the algorithm finds the best beamlet weight to reduce toxicity risks to normal tissue while holding the objective function achieved in the first step as a constraint, with a small amount of allowed slip. Likewise, the third and fourth steps introduce lower priority normal tissue goals and beam smoothing. We compared with prostate treatment plans from Memorial Sloan Kettering Cancer Center developed using Eclipse, with a prescription dose of 72 Gy. A combination of liear, quadratic, and gEUD objective functions were used with a modified open source solver code (IPOPT). Results Initial plan results on 3 different cases show that the automated planning system is capable of competing or improving on expert-driven eclipse plans. Compared to the Eclipse planning system, the automated system produced up to 26% less mean dose to rectum and 24% less mean dose to bladder while having the same D95 (after matching) to the target. Conclusion We have demonstrated that Pareto optimal treatment plans can be generated automatically without a trial-and-error process. The solver finds an optimal plan for the given patient, as opposed to database-driven approaches that set parameters based on geometry and population modeling.

  20. SU-F-T-391: Comparative Study of Treatment Planning Between IMRT and IMAT for Malignant Pleural Mesothelioma

    Energy Technology Data Exchange (ETDEWEB)

    Duan, J [Shandong Cancer Hospital and Institute, Jinan, Shandong province (China)

    2016-06-15

    Purpose: The purpose of this study was to compare the dosimetric differences between intensitymodulated radiation therapy (IMRT) and intensity modulated arc therapy (IMAT) for malignant pleural mesothelioma (MPM) patients with regard to the sparing effect on organs at risk (OARs), plan quality, and delivery efficiency. Methods: Ten MPM patients were recruited in this study. To avoid the inter-operator variability, IMRT and IMAT plans for each patient were performed by one experienced dosimetrist. The treatment planning optimization process was carried out using the Eclipse 13.0 software. For a fair comparison, the planning target volume (PTV) coverage of the two plans was normalized to the same level. The treatment plans were evaluated on the following dosimetric variables: conformity index (CI) and homogeneity index (HI) for PTV, OARs dose, and the delivery efficiency for each plan. Results: All plans satisfied clinical requirements. The IMAT plans gained better CI and HI. The IMRT plans performed better sparing for heart and lung. Less MUs and control points were found in the IMAT plans. IMAT shortened delivery time compared with IMRT. Conclusion: For MPM, IMAT gains better conformity and homogeneity for PTV with IMRT, but increases the irradiation dose for OARs. IMAT shows an advantage in delivery efficiency.

  1. [Motivational interviewing integrated into cognitive behavioral therapy in obesity treatment].

    Science.gov (United States)

    Reiner, M; Carrard, I; Golay, A

    2010-03-31

    Cognitive behavioural therapy is a well-known approach which has proved its efficacy in the treatment of eating disorders and obesity. Nevertheless, eating disordered and obese patients are often ambivalent towards treatment and as a consequence, they can't benefit fully from therapy or drop out easily. Nowadays, motivational issues are widely recognized as a critical point. Motivational Interviewing is now considered as valuable to enhance compliance to treatments.

  2. The use of photodynamic therapy in the treatment of keratoacanthomas

    Directory of Open Access Journals (Sweden)

    V. N. Galkin

    2016-01-01

    Full Text Available The review is on treatment of keratoacanthomas using photodynamic therapy. The defining characteristic of keratoacanthoma among epithelial tumors is a rapid spontaneous regression in the case of typical keratoacanthoma and long-term persistence, recurrence and common malignant transformation to squamous cell carcinoma in the case of atypical keratoacanthoma. In recent years, photodynamic therapy which is an effective method of treatment of different types of cancer and pre-cancer diseases of the skin including actinic keratosis, Bowen’s disease, basal cell carcinoma, is increasingly used in clinical practice. There are few data for photodynamic therapy in the treatment of keratoacanthoma. The analysis of the literature shows that using of photodynamic therapy in the set of treatment modalities in patients with keratoacanthoma improves the efficacy and reduces the terms of the therapy. In all investigations except one there was complete tumor regression in 100% patients with keratoacanthoma who underwent photodynamic therapy. In one study complete tumor regression was observed in 66.7% of patients with atypical keratoacanthoma after photodynamic therapy. The follow-up of patients in all analyzed studies accounted for at least 2-3 years. During this time none of the patients had evidence for recurrence. This approach has minimal restrictions for application. Thus, photodynamic therapy may become a therapeutic alternative to surgical treatment of keratoacanthoma with good clinical and cosmetic results.

  3. [Ozone therapy combined with sulfasalazine delivered via a colon therapy system for treatment of ulcerative colitis].

    Science.gov (United States)

    Geng, Yan; Wang, Wei; Ma, Qiang; Peng, Li-qiong; Liang, Zhong-hui

    2010-12-01

    To assess the therapeutic effect of ozone therapy combined with sulfasalazine sulfasalazine delivered via a colon therapy system in the treatment of distal ulcerative colitis. This prospective randomized controlled clinical trial involved 54 patients with mild to moderate active distal ulcerative colitis, who were randomize into 3 groups in accordance with the inclusion criteria (n=18). Each group was given sulfasalazine at the daily dose of 2 g, and in colon therapy group and ozone therapy plus sulfasalazine therapy group, sulfasalazine was delivered via a colon therapy system on a daily basis; the control group received sulfasalazine via retention enema only. At 0, 2, and 4 weeks of the treatment, colonoscopy was performed to evaluate the disease activity, and biopsy samples were obtained at 0 and 4 weeks for histological examination. In comparison with colon therapy group and control group, ozone therapy plus colon therapy resulted in more rapid alleviation of the clinical symptoms and better histological improvement without any adverse effects. Ozone therapy combined with sulfasalazine delivered via a colon therapy system is feasible and effective for treatment of ulcerative colitis.

  4. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning

    Science.gov (United States)

    Thomas, T. Hannah Mary; Devakumar, D.; Purnima, S.; Ravindran, B. Paul

    2009-04-01

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm × 10 cm beam at a gantry angle of 0° and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between ±6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.

  5. Feasibility of using glass-bead thermoluminescent dosimeters for radiotherapy treatment plan verification

    Science.gov (United States)

    Jordan, Tom J; Distefano, Gail; Bradley, David A; Spyrou, Nicholas M; Nisbet, Andrew; Clark, Catharine H

    2015-01-01

    Objective: To investigate the feasibility of using glass beads as novel thermoluminescent dosemeters (TLDs) for radiotherapy treatment plan verification. Methods: Commercially available glass beads with a size of 1-mm thickness and 2-mm diameter were characterized as TLDs. Five clinical treatment plans including a conventional larynx, a conformal prostate, an intensity-modulated radiotherapy (IMRT) prostate and two stereotactic body radiation therapy (SBRT) lung plans were transferred onto a CT scan of a water-equivalent phantom (Solid Water®, Gammex, Middleton, WI) and the dose distribution recalculated. The number of monitor units was maintained from the clinical plan and delivered accordingly. The doses determined by the glass beads were compared with those measured by a graphite-walled ionization chamber, and the respective expected doses were determined by the treatment-planning system (TPS) calculation. Results: The mean percentage difference between measured dose with the glass beads and TPS was found to be 0.3%, −0.1%, 0.4%, 1.8% and 1.7% for the conventional larynx, conformal prostate, IMRT prostate and each of the SBRT delivery techniques, respectively. The percentage difference between measured dose with the ionization chamber and glass bead was found to be −1.2%, −1.4%, −0.1%, −0.9% and 2.4% for the above-mentioned plans, respectively. The results of measured doses with the glass beads and ionization chamber in comparison with expected doses from the TPS were analysed using a two-sided paired t-test, and there was no significant difference at p glass-bead TLDs as dosemeters in a range of clinical plan verifications. Advances in knowledge: Commercial glass beads are utilized as low-cost novel TLDs for treatment-plan verification. PMID:26258442

  6. Interactive Dose Shaping - efficient strategies for CPU-based real-time treatment planning

    Science.gov (United States)

    Ziegenhein, P.; Kamerling, C. P.; Oelfke, U.

    2014-03-01

    Conventional intensity modulated radiation therapy (IMRT) treatment planning is based on the traditional concept of iterative optimization using an objective function specified by dose volume histogram constraints for pre-segmented VOIs. This indirect approach suffers from unavoidable shortcomings: i) The control of local dose features is limited to segmented VOIs. ii) Any objective function is a mathematical measure of the plan quality, i.e., is not able to define the clinically optimal treatment plan. iii) Adapting an existing plan to changed patient anatomy as detected by IGRT procedures is difficult. To overcome these shortcomings, we introduce the method of Interactive Dose Shaping (IDS) as a new paradigm for IMRT treatment planning. IDS allows for a direct and interactive manipulation of local dose features in real-time. The key element driving the IDS process is a two-step Dose Modification and Recovery (DMR) strategy: A local dose modification is initiated by the user which translates into modified fluence patterns. This also affects existing desired dose features elsewhere which is compensated by a heuristic recovery process. The IDS paradigm was implemented together with a CPU-based ultra-fast dose calculation and a 3D GUI for dose manipulation and visualization. A local dose feature can be implemented via the DMR strategy within 1-2 seconds. By imposing a series of local dose features, equal plan qualities could be achieved compared to conventional planning for prostate and head and neck cases within 1-2 minutes. The idea of Interactive Dose Shaping for treatment planning has been introduced and first applications of this concept have been realized.

  7. Feasibility of using glass-bead thermoluminescent dosimeters for radiotherapy treatment plan verification.

    Science.gov (United States)

    Jafari, Shakardokht M; Jordan, Tom J; Distefano, Gail; Bradley, David A; Spyrou, Nicholas M; Nisbet, Andrew; Clark, Catharine H

    2015-01-01

    To investigate the feasibility of using glass beads as novel thermoluminescent dosemeters (TLDs) for radiotherapy treatment plan verification. Commercially available glass beads with a size of 1-mm thickness and 2-mm diameter were characterized as TLDs. Five clinical treatment plans including a conventional larynx, a conformal prostate, an intensity-modulated radiotherapy (IMRT) prostate and two stereotactic body radiation therapy (SBRT) lung plans were transferred onto a CT scan of a water-equivalent phantom (Solid Water(®), Gammex, Middleton, WI) and the dose distribution recalculated. The number of monitor units was maintained from the clinical plan and delivered accordingly. The doses determined by the glass beads were compared with those measured by a graphite-walled ionization chamber, and the respective expected doses were determined by the treatment-planning system (TPS) calculation. The mean percentage difference between measured dose with the glass beads and TPS was found to be 0.3%, -0.1%, 0.4%, 1.8% and 1.7% for the conventional larynx, conformal prostate, IMRT prostate and each of the SBRT delivery techniques, respectively. The percentage difference between measured dose with the ionization chamber and glass bead was found to be -1.2%, -1.4%, -0.1%, -0.9% and 2.4% for the above-mentioned plans, respectively. The results of measured doses with the glass beads and ionization chamber in comparison with expected doses from the TPS were analysed using a two-sided paired t-test, and there was no significant difference at p glass-bead TLDs as dosemeters in a range of clinical plan verifications. Commercial glass beads are utilized as low-cost novel TLDs for treatment-plan verification.

  8. The consequence of day-to-day stochastic dose deviation from the planned dose in fractionated radiation therapy.

    Science.gov (United States)

    Paul, Subhadip; Roy, Prasun Kumar

    2016-02-01

    Radiation therapy is one of the important treatment procedures of cancer. The day-to-day delivered dose to the tissue in radiation therapy often deviates from the planned fixed dose per fraction. This day-to-day variation of radiation dose is stochastic. Here, we have developed the mathematical formulation to represent the day-to-day stochastic dose variation effect in radiation therapy. Our analysis shows that that the fixed dose delivery approximation under-estimates the biological effective dose, even if the average delivered dose per fraction is equal to the planned dose per fraction. The magnitude of the under-estimation effect relies upon the day-to-day stochastic dose variation level, the dose fraction size and the values of the radiobiological parameters of the tissue. We have further explored the application of our mathematical formulation for adaptive dose calculation. Our analysis implies that, compared to the premise of the Linear Quadratic Linear (LQL) framework, the Linear Quadratic framework based analytical formulation under-estimates the required dose per fraction necessary to produce the same biological effective dose as originally planned. Our study provides analytical formulation to calculate iso-effect in adaptive radiation therapy considering day-to-day stochastic dose deviation from planned dose and also indicates the potential utility of LQL framework in this context.

  9. Short-term efficacy of physical therapy compared to splint therapy in treatment of arthrogenous TMD.

    Science.gov (United States)

    Ismail, F; Demling, A; Hessling, K; Fink, M; Stiesch-Scholz, M

    2007-11-01

    A prospective randomized study was carried out to evaluate the efficacy of physical therapy in addition to splint therapy on treatment outcome in patients with temporomandibular disorders (TMD) with respect to objective and subjective parameters. Twenty-six patients suffering from an arthrogenic TMD and exhibiting a painfully restricted jaw opening were randomized in two groups. Thirteen patients were treated solely with Michigan splint (group I), 13 patients received supplementary physical therapy (group II). Before treatment a clinical examination and electronic recording of jaw movements were performed and subjective pain level was evaluated by visual analogue scales. After 3 months of therapy maintenance of improvement was evaluated. Within treatment groups comparison of data before and after treatment was analysed using Wilcoxon test. Groups were compared by Mann-Withney-U test. A P-value treatment, whereas subjective pain decreased significantly (P treatment outcome of patients with TMD.

  10. Sparsity constrained split feasibility for dose-volume constraints in inverse planning of intensity-modulated photon or proton therapy

    Science.gov (United States)

    Penfold, Scott; Zalas, Rafał; Casiraghi, Margherita; Brooke, Mark; Censor, Yair; Schulte, Reinhard

    2017-05-01

    A split feasibility formulation for the inverse problem of intensity-modulated radiation therapy treatment planning with dose-volume constraints included in the planning algorithm is presented. It involves a new type of sparsity constraint that enables the inclusion of a percentage-violation constraint in the model problem and its handling by continuous (as opposed to integer) methods. We propose an iterative algorithmic framework for solving such a problem by applying the feasibility-seeking CQ-algorithm of Byrne combined with the automatic relaxation method that uses cyclic projections. Detailed implementation instructions are furnished. Functionality of the algorithm was demonstrated through the creation of an intensity-modulated proton therapy plan for a simple 2D C-shaped geometry and also for a realistic base-of-skull chordoma treatment site. Monte Carlo simulations of proton pencil beams of varying energy were conducted to obtain dose distributions for the 2D test case. A research release of the Pinnacle 3 proton treatment planning system was used to extract pencil beam doses for a clinical base-of-skull chordoma case. In both cases the beamlet doses were calculated to satisfy dose-volume constraints according to our new algorithm. Examination of the dose-volume histograms following inverse planning with our algorithm demonstrated that it performed as intended. The application of our proposed algorithm to dose-volume constraint inverse planning was successfully demonstrated. Comparison with optimized dose distributions from the research release of the Pinnacle 3 treatment planning system showed the algorithm could achieve equivalent or superior results.

  11. Use of PET/CT instead of CT-only when planning for radiation therapy does not notably increase life years lost in children being treated for cancer

    DEFF Research Database (Denmark)

    Kornerup, Josefine S.; Brodin, Nils Patrik; Christensen, Charlotte Birk

    2015-01-01

    BACKGROUND: PET/CT may be more helpful than CT alone for radiation therapy planning, but the added risk due to higher doses of ionizing radiation is unknown. OBJECTIVE: To estimate the risk of cancer induction and mortality attributable to the [F-18]2-fluoro-2-deoxyglucose (FDG) PET and CT scans...... used for radiation therapy planning in children with cancer, and compare to the risks attributable to the cancer treatment. MATERIALS AND METHODS: Organ doses and effective doses were estimated for 40 children (2-18 years old) who had been scanned using PET/CT as part of radiation therapy planning....... Multivariate linear regression was performed to find predictors for a high contribution to life years lost from the radiation therapy planning diagnostics. RESULTS: The mean contribution from PET to the effective dose from one PET/CT scan was 24% (range: 7-64%). The average proportion of life years lost...

  12. Treatment Compliance in Group Therapy: Issues and Interventions

    Science.gov (United States)

    Hunnicutt Hollenbaugh, Karen Michelle

    2011-01-01

    In this manuscript, research on treatment compliance and dropout in group therapy is reviewed. A number of variables found to be related to the compliance and dropout are identified including client characteristics, treatment characteristics, and therapist perceptions and behavior. Implications of these results for increasing treatment compliance…

  13. Novel tools for stepping source brachytherapy treatment planning: Enhanced geometrical optimization and interactive inverse planning

    Energy Technology Data Exchange (ETDEWEB)

    Dinkla, Anna M., E-mail: a.m.dinkla@amc.uva.nl; Laarse, Rob van der; Koedooder, Kees; Petra Kok, H.; Wieringen, Niek van; Pieters, Bradley R.; Bel, Arjan [Department of Radiation Oncology, Academic Medical Center Amsterdam, Meibergdreef 9, Amsterdam 1105 AZ (Netherlands)

    2015-01-15

    Purpose: Dose optimization for stepping source brachytherapy can nowadays be performed using automated inverse algorithms. Although much quicker than graphical optimization, an experienced treatment planner is required for both methods. With automated inverse algorithms, the procedure to achieve the desired dose distribution is often based on trial-and-error. Methods: A new approach for stepping source prostate brachytherapy treatment planning was developed as a quick and user-friendly alternative. This approach consists of the combined use of two novel tools: Enhanced geometrical optimization (EGO) and interactive inverse planning (IIP). EGO is an extended version of the common geometrical optimization method and is applied to create a dose distribution as homogeneous as possible. With the second tool, IIP, this dose distribution is tailored to a specific patient anatomy by interactively changing the highest and lowest dose on the contours. Results: The combined use of EGO–IIP was evaluated on 24 prostate cancer patients, by having an inexperienced user create treatment plans, compliant to clinical dose objectives. This user was able to create dose plans of 24 patients in an average time of 4.4 min/patient. An experienced treatment planner without extensive training in EGO–IIP also created 24 plans. The resulting dose-volume histogram parameters were comparable to the clinical plans and showed high conformance to clinical standards. Conclusions: Even for an inexperienced user, treatment planning with EGO–IIP for stepping source prostate brachytherapy is feasible as an alternative to current optimization algorithms, offering speed, simplicity for the user, and local control of the dose levels.

  14. 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.

  15. Draft Site Treatment Plan (DSTP), Volumes I and II

    Energy Technology Data Exchange (ETDEWEB)

    D`Amelio, J.

    1994-08-30

    Site Treatment Plans (STP) are required for facilities at which the DOE generates or stores mixed waste. This Draft Site Treatment Plan (DSTP) the second step in a three-phase process, identifies the currently preferred options for treating mixed waste at the Savannah River Site (SRS) or for developing treatment technologies where technologies do not exist or need modification. The DSTP reflects site-specific preferred options, developed with the state`s input and based on existing available information. To the extent possible, the DSTP identifies specific treatment facilities for treating the mixed waste and proposes schedules. Where the selection of specific treatment facilities is not possible, schedules for alternative activities such as waste characterization and technology assessment are provided. All schedule and cost information presented is preliminary and is subject to change. The DSTP is comprised of two volumes: this Compliance Plan Volume and the Background Volume. This Compliance Plan Volume proposes overall schedules with target dates for achieving compliance with the land disposal restrictions (LDR) of RCRA and procedures for converting the target dates into milestones to be enforced under the Order. The more detailed discussion of the options contained in the Background Volume is provided for informational purposes only.

  16. Density overwrites of internal tumor volumes in intensity modulated proton therapy plans for mobile lung tumors

    Science.gov (United States)

    Botas, Pablo; Grassberger, Clemens; Sharp, Gregory; Paganetti, Harald

    2018-02-01

    The purpose of this study was to investigate internal tumor volume density overwrite strategies to minimize intensity modulated proton therapy (IMPT) plan degradation of mobile lung tumors. Four planning paradigms were compared for nine lung cancer patients. Internal gross tumor volume (IGTV) and internal clinical target volume (ICTV) structures were defined encompassing their respective volumes in every 4DCT phase. The paradigms use different planning CT (pCT) created from the average intensity projection (AIP) of the 4DCT, overwriting the density within the IGTV to account for movement. The density overwrites were: (a) constant filling with 100 HU (C100) or (b) 50 HU (C50), (c) maximum intensity projection (MIP) across phases, and (d) water equivalent path length (WEPL) consideration from beam’s-eye-view. Plans were created optimizing dose-influence matrices calculated with fast GPU Monte Carlo (MC) simulations in each pCT. Plans were evaluated with MC on the 4DCTs using a model of the beam delivery time structure. Dose accumulation was performed using deformable image registration. Interplay effect was addressed applying 10 times rescanning. Significantly less DVH metrics degradation occurred when using MIP and WEPL approaches. Target coverage (D99≥slant 70 Gy(RBE)) was fulfilled in most cases with MIP and WEPL (D{{99}WEPL}=69.2+/- 4.0 Gy (RBE)), keeping dose heterogeneity low (D5-D{{95}WEPL}=3.9+/- 2.0 Gy(RBE)). The mean lung dose was kept lowest by the WEPL strategy, as well as the maximum dose to organs at risk (OARs). The impact on dose levels in the heart, spinal cord and esophagus were patient specific. Overall, the WEPL strategy gives the best performance and should be preferred when using a 3D static geometry for lung cancer IMPT treatment planning. Newly available fast MC methods make it possible to handle long simulations based on 4D data sets to perform studies with high accuracy and efficiency, even prior to individual treatment planning.

  17. Pre-treatment amygdala volume predicts electroconvulsive therapy response

    NARCIS (Netherlands)

    ten Doesschate, Freek; van Eijndhoven, Philip; Tendolkar, Indira; van Wingen, Guido A.; van Waarde, Jeroen A.

    2014-01-01

    Electroconvulsive therapy (ECT) is an effective treatment for patients with severe depression. Knowledge on factors predicting therapeutic response may help to identify patients who will benefit most from the intervention. Based on the neuroplasticity hypothesis, volumes of the amygdala and

  18. Consideration of treatment fidelity to improve manual therapy research

    National Research Council Canada - National Science Library

    Karas, Steve; Plankis, Laura

    2016-01-01

    The purpose of this paper was to define treatment fidelity, review its use in health care research and suggest how it may be utilized in manual therapy research to improve the reliability and validity of the literature...

  19. Assessment of the Evolution of Cancer Treatment Therapies

    Directory of Open Access Journals (Sweden)

    Mónica Valladares

    2011-08-01

    Full Text Available Cancer therapy has been characterized throughout history by ups and downs, not only due to the ineffectiveness of treatments and side effects, but also by hope and the reality of complete remission and cure in many cases. Within the therapeutic arsenal, alongside surgery in the case of solid tumors, are the antitumor drugs and radiation that have been the treatment of choice in some instances. In recent years, immunotherapy has become an important therapeutic alternative, and is now the first choice in many cases. Nanotechnology has recently arrived on the scene, offering nanostructures as new therapeutic alternatives for controlled drug delivery, for combining imaging and treatment, applying hyperthermia, and providing directed target therapy, among others. These therapies can be applied either alone or in combination with other components (antibodies, peptides, folic acid, etc.. In addition, gene therapy is also offering promising new methods for treatment. Here, we present a review of the evolution of cancer treatments, starting with chemotherapy, surgery, radiation and immunotherapy, and moving on to the most promising cutting-edge therapies (gene therapy and nanomedicine. We offer an historical point of view that covers the arrival of these therapies to clinical practice and the market, and the promises and challenges they present.

  20. Assessment of the Evolution of Cancer Treatment Therapies

    Energy Technology Data Exchange (ETDEWEB)

    Arruebo, Manuel [Instituto de Nanociencia de Aragón (INA), Mariano Esquillor, Edif. I+D, University of Zaragoza, Zaragoza 50018 (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza 50018 (Spain); Vilaboa, Nuria [CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza 50018 (Spain); Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, Madrid 28046 (Spain); Sáez-Gutierrez, Berta; Lambea, Julio; Tres, Alejandro [Instituto de Nanociencia de Aragón (INA), Mariano Esquillor, Edif. I+D, University of Zaragoza, Zaragoza 50018 (Spain); Servicio de Oncología Médica, Hospital Clínico Universitario Lozano Blesa, Avda. San Juan Bosco 50009, Zaragoza (Spain); Instituto Aragonés de Ciencias de la Salud (I-CS), Avda. Gómez Laguna, 25, Zaragoza 50009 (Spain); Valladares, Mónica [Lonza Biologics Porriño, A relva s/n, Porriño (Pontevedra) 36410 (Spain); González-Fernández, África, E-mail: africa@uvigo.es [Immunology Department, Biomedical Research Center (CINBIO), University of Vigo, Campus Lagoas Marcosende, Vigo (Pontevedra) 36310 (Spain)

    2011-08-12

    Cancer therapy has been characterized throughout history by ups and downs, not only due to the ineffectiveness of treatments and side effects, but also by hope and the reality of complete remission and cure in many cases. Within the therapeutic arsenal, alongside surgery in the case of solid tumors, are the antitumor drugs and radiation that have been the treatment of choice in some instances. In recent years, immunotherapy has become an important therapeutic alternative, and is now the first choice in many cases. Nanotechnology has recently arrived on the scene, offering nanostructures as new therapeutic alternatives for controlled drug delivery, for combining imaging and treatment, applying hyperthermia, and providing directed target therapy, among others. These therapies can be applied either alone or in combination with other components (antibodies, peptides, folic acid, etc.). In addition, gene therapy is also offering promising new methods for treatment. Here, we present a review of the evolution of cancer treatments, starting with chemotherapy, surgery, radiation and immunotherapy, and moving on to the most promising cutting-edge therapies (gene therapy and nanomedicine). We offer an historical point of view that covers the arrival of these therapies to clinical practice and the market, and the promises and challenges they present.

  1. Phase 1-2 Study of Dual-Energy Computed Tomography for Assessment of Pulmonary Function in Radiation Therapy Planning.

    Science.gov (United States)

    Bahig, Houda; Campeau, Marie-Pierre; Lapointe, Andréanne; Bedwani, Stephane; Roberge, David; de Guise, Jacques; Blais, Danis; Vu, Toni; Lambert, Louise; Chartrand-Lefebvre, Carl; Lord, Martin; Filion, Edith

    2017-10-01

    To quantify lung function according to a dual-energy computed tomography (DECT)-derived iodine map in patients treated with radiation therapy for lung cancer, and to assess the dosimetric impact of its integration in radiation therapy planning. Patients treated with stereotactic ablative radiation therapy for early-stage or intensity modulated radiation therapy for locally advanced lung cancer were prospectively enrolled in this study. A DECT in treatment position was obtained at time of treatment planning. The relative contribution of each voxel to the total lung function was based on iodine distribution. The composition of each voxel was determined on the basis of a 2-material decomposition. The DECT-derived lobar function was compared with single photon emission computed tomography/computed tomography (SPECT/CT). A functional map was integrated in the treatment planning system using 6 subvolumes of increasing iodine distribution levels. Percent lung volume receiving 5 Gy (V5), V20, and mean dose (MLD) to whole lungs (anatomic) versus functional lungs were compared. Twenty-five patients with lung cancer, including 18 patients treated with stereotactic ablative radiation therapy and 7 patients with intensity modulated radiation therapy (locally advanced), were included. Eighty-four percent had chronic obstructive pulmonary disease. Median (range) forced expiratory volume in 1 second was 62% of predicted (29%-113%), and median diffusing capacity of the lung for carbon monoxide was 56% (39%-91%). There was a strong linear correlation between DECT- and SPECT/CT-derived lobar function (Pearson coefficient correlation r=0.89, P<.00001). Mean (range) differences in V5, V20, and MLD between anatomic and functional lung volumes were 16% (0%-48%, P=.03), 5% (1%-15%, P=.12), and 15% (1%-43%, P=.047), respectively. Lobar function derived from a DECT iodine map correlates well with SPECT/CT, and its integration in lung treatment planning is associated with significant

  2. Application of the thermoluminescent (TL) and optically stimulated luminescence (OSL) dosimetry techniques to determinate the isodose curves in a cancer treatment planning simulation using Volumetric Modulated Arc Therapy - VMAT; Aplicacao das tecnicas de dosimetria termoluminescente (TL) e luminescencia opticamente estimulada (OSL) na determinacao de curvas de isodose em uma simulacao de tratamento de cancer pela tecnica de radioterapia em arco modulado volumetrico - VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Bravim, Amanda

    2015-07-01

    The Volumetric Modulated Arc Therapy (VMAT) is an advance technique of Intensity Modulated Radiation Therapy (IMRT). This progress is due to the continuous gantry rotation with the radiation beam modulation providing lower time of the patient treatment. This research aimed the verification of the isodose curves in a simulation of a vertebra treatment with spinal cord protection using the thermoluminescent (TL) and optically stimulated luminescence (OSL) dosimetry techniques and the LiF:Mg,Ti (TLD-100), CaS0{sub 4}:Dy and Al{sub 2}0{sub 3}:C dosimeters and LiF:Mg,Ti micro dosimeters (TLD-100). The dosimeters were characterized using PMMA plates of 30 x 30 x 30 cm{sup 3} and different thickness. All irradiations were done using Truebeam STx linear accelerator of Hospital Israelita Albert Einstein, with 6 MV photons beam. After the dosimeter characterization, they were irradiated according the specific planning simulation and using a PMMA phantom developed to VMAT measurements. This irradiation aimed to verify the isodose curves of the treatment simulation using the two dosimetry techniques. All types of dosimeters showed satisfactory results to determine the dose distribution but analysing the complexity of the isodose curves and the proximity of them, the LiF:Mg,Ti micro dosimeter showed the most appropriate for use due to its small dimensions. Regarding the best technique, as both technique showed satisfactory results, the TL technique presents less complex to be used because the most of the radiotherapy departments already have a TL laboratory. The OSL technique requires more care and greater investment in the hospital. (author)

  3. Generation of composite dose and biological effective dose (BED) over multiple treatment modalities and multistage planning using deformable image registration.

    Science.gov (United States)

    Zhang, Geoffrey; Huang, Tzung-Chi; Feygelman, Vladimir; Stevens, Craig; Forster, Kenneth

    2010-01-01

    Currently there are no commercially available tools to generate composite plans across different treatment modalities and/or different planning image sets. Without a composite plan, it may be difficult to perform a meaningful dosimetric evaluation of the overall treatment course. In this paper, we introduce a method to generate composite biological effective dose (BED) plans over multiple radiotherapy treatment modalities and/or multistage plans, using deformable image registration. Two cases were used to demonstrate the method. Case I was prostate cancer treated with intensity-modulated radiation therapy (IMRT) and a permanent seed implant. Case II involved lung cancer treated with two treatment plans generated on two separate computed tomography image sets. Thin-plate spline or optical flow methods were used as appropriate to generate deformation matrices. The deformation matrices were then applied to the dose matrices and the resulting physical doses were converted to BED and added to yield the composite plan. Cell proliferation and sublethal repair were considered in the BED calculations. The difference in BED between normal tissues and tumor volumes was accounted for by using different BED models, alpha/beta values, and cell potential doubling times. The method to generate composite BED plans presented in this paper provides information not available with the traditional simple dose summation or physical dose summation. With the understanding of limitations and uncertainties of the algorithms involved, it may be valuable for the overall treatment plan evaluation. 2010 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  4. Photodynamic Therapy in Dermatology: Current Treatments and Implications

    OpenAIRE

    Kostovic, Kresimir; Pastar, Zrinjka; Ceovic, Romana; Bukvic Mokos, Zrinka; Stulhofer Buzina, Daska; Stanimirovic, Andrija

    2012-01-01

    This article provides an update on photodynamic therapy by discussing each of the essential components in sequence: mechanisms of action, common photosensitizers, typical light sources, and indications. In dermatology, photodynamic therapy (PDT) is mainly used in the treatment of superficial skin cancers: actinic keratoses, Bowen’s disease and superficial basal cell carcinomas. However, the range of indications has been expanding continuously. PDT is also used for the treatment of other on...

  5. Mediators and treatment matching in behavior therapy, cognitive therapy and cognitive behavior therapy for chronic insomnia.

    Science.gov (United States)

    Harvey, Allison G; Dong, Lu; Bélanger, Lynda; Morin, Charles M

    2017-10-01

    To examine the mediators and the potential of treatment matching to improve outcome for cognitive behavior therapy (CBT) for insomnia. Participants were 188 adults (117 women; Mage = 47.4 years, SD = 12.6) meeting the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; text rev.; DSM-IV-TR; American Psychiatric Association [APA], 2000) diagnostic criteria for chronic insomnia (Mduration: 14.5 years, SD: 12.8). Participants were randomized to behavior therapy (BT; n = 63), cognitive therapy (CT; n = 65), or CBT (n = 60). The outcome measure was the Insomnia Severity Index (ISI). Hypothesized BT mediators were sleep-incompatible behaviors, bedtime variability (BTv), risetime variability (RTv) and time in bed (TIB). Hypothesized CT mediators were worry, unhelpful beliefs, and monitoring for sleep-related threat. The behavioral processes mediated outcome for BT but not CT. The cognitive processes mediated outcome in both BT and CT. The subgroup scoring high on both behavioral and cognitive processes had a marginally significant better outcome if they received CBT relative to BT or CT. The subgroup scoring relatively high on behavioral but low on cognitive processes and received BT or CBT did not differ from those who received CT. The subgroup scoring relatively high on cognitive but low on behavioral processes and received CT or CBT did not differ from those who received BT. The behavioral mediators were specific to BT relative to CT. The cognitive mediators were significant for both BT and CT outcomes. Patients exhibiting high levels of both behavioral and cognitive processes achieve better outcome if they receive CBT relative to BT or CT alone. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. Proton therapy versus intensity modulated x-ray therapy in the treatment of prostate cancer: Estimating secondary cancer risks

    Science.gov (United States)

    Fontenot, Jonas David

    External beam radiation therapy is used to treat nearly half of the more than 200,000 new cases of prostate cancer diagnosed in the United States each year. During a radiation therapy treatment, healthy tissues in the path of the therapeutic beam are exposed to high doses. In addition, the whole body is exposed to a low-dose bath of unwanted scatter radiation from the pelvis and leakage radiation from the treatment unit. As a result, survivors of radiation therapy for prostate cancer face an elevated risk of developing a radiogenic second cancer. Recently, proton therapy has been shown to reduce the dose delivered by the therapeutic beam to normal tissues during treatment compared to intensity modulated x-ray therapy (IMXT, the current standard of care). However, the magnitude of stray radiation doses from proton therapy, and their impact on this incidence of radiogenic second cancers, was not known. The risk of a radiogenic second cancer following proton therapy for prostate cancer relative to IMXT was determined for 3 patients of large, median, and small anatomical stature. Doses delivered to healthy tissues from the therapeutic beam were obtained from treatment planning system calculations. Stray doses from IMXT were taken from the literature, while stray doses from proton therapy were simulated using a Monte Carlo model of a passive scattering treatment unit and an anthropomorphic phantom. Baseline risk models were taken from the Biological Effects of Ionizing Radiation VII report. A sensitivity analysis was conducted to characterize the uncertainty of risk calculations to uncertainties in the risk model, the relative biological effectiveness (RBE) of neutrons for carcinogenesis, and inter-patient anatomical variations. The risk projections revealed that proton therapy carries a lower risk for radiogenic second cancer incidence following prostate irradiation compared to IMXT. The sensitivity analysis revealed that the results of the risk analysis depended only

  7. 3718-F Alkali Metal Treatment and Storage Facility Closure Plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    1991-12-01

    Since 1987, Westinghouse Hanford Company has been a major contractor to the U.S. Department of Energy-Richland Operations Office and has served as co-operator of the 3718-F Alkali Metal Treatment and Storage Facility, the waste management unit addressed in this closure plan. The closure plan consists of a Part A Dangerous waste Permit Application and a RCRA Closure Plan. An explanation of the Part A Revision (Revision 1) submitted with this document is provided at the beginning of the Part A section. The closure plan consists of 9 chapters and 5 appendices. The chapters cover: introduction; facility description; process information; waste characteristics; groundwater; closure strategy and performance standards; closure activities; postclosure; and references.

  8. A simple planning technique of craniospinal irradiation in the eclipse treatment planning system

    Directory of Open Access Journals (Sweden)

    Hemalatha Athiyaman

    2014-01-01

    Full Text Available A new planning method for Craniospinal Irradiation by Eclipse treatment planning system using Field alignment, Field-in-Field technique was developed. Advantage of this planning method was also studied retrospectively for previously treated five patients of medulloblastoma with variable spine length. Plan consists of half beam blocked parallel opposed cranium, and a single posterior cervicospine field was created by sharing the same isocenter, which obviates divergence matching. Further, a single symmetrical field was created to treat remaining Lumbosacral spine. Matching between a inferior diverging edge of cervicospine field and superior diverging edge of a Lumbosacral field was done using the field alignment option. ′Field alignment′ is specific option in the Eclipse Treatment Planning System, which automatically matches the field edge divergence as per field alignment rule. Multiple segments were applied in both the spine field to manage with hot and cold spots created by varying depth of spinal cord. Plan becomes fully computerized using this field alignment option and multiple segments. Plan evaluation and calculated mean modified Homogeneity Index (1.04 and 0.1 ensured that dose to target volume is homogeneous and critical organ doses were within tolerance. Dose variation at the spinal field junction was verified using ionization chamber array (I′MatriXX for matched, overlapped and gap junction spine fields; the delivered dose distribution confirmed the ideal clinical match, over exposure and under exposure at the junction, respectively. This method is simple to plan, executable in Record and Verify mode and can be adopted for various length of spinal cord with only two isocenter in shorter treatment time.

  9. Dental student perceptions of predoctoral implant education and plans for providing implant treatment.

    Science.gov (United States)

    Yuan, Judy Chia-Chun; Kaste, Linda M; Lee, Damian J; Harlow, Rand F; Knoernschild, Kent L; Campbell, Stephen D; Sukotjo, Cortino

    2011-06-01

    This study aims to identify dental students' perceptions of pre-patient care laboratory exercises (PCLEs) and clinical experiences that influence their future plans for providing implant care. One of two questionnaires was administered to dental student classes at one dental school (D2: Survey 1; D3 and D4: Survey 2). Future plans as graduates to provide implant diagnosis and treatment planning (DxTP), restoration of single-tooth implants (STIs), and implant-retained overdentures (IODs) were cross-sectionally assessed along with potential influences such as PCLE, clinical experiences, gender, and class. The majority of students planned to provide implant services after graduation (DxTP 68.9 percent; STI 61.2 percent; IOD 62.1 percent). Bivariately, males reflected more preparedness from PCLEs than females (p=.002) and the D2 students more than D3 and D4 students (pimplant therapy. However, this varied by gender and class. These findings indicate that PCLEs are important for their influence on students' future plans to provide implant therapy. However, further studies are needed to validate actual PCLEs and clinical implant practices (both longitudinally and for other schools) and to determine educational interventions to optimize the provision of implant care.

  10. Treatment planning decisions: implant placement versus preserving natural teeth.

    Science.gov (United States)

    Moshaverinia, Alireza; Kar, Klan; Chee, Winston W L

    2014-12-01

    Dental implants are routinely used as a treatment modality for replacing missing teeth. An assessment of whether to extract teeth and place implants or preserve natural dentition can be a complex decision-making process. The purpose of this article is to review some of the factors that influence prosthetic planning of functional and esthetic rehabilitation for patients with diseased dentition either with conventional treatment options or with extractions and replacement with implant-supported prosthesis.

  11. WE-G-16A-01: Evolution of Radiation Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Rothenberg, L [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Mohan, R [UT MD Anderson Cancer Center, Houston, TX (United States); Van Dyk, J [Western University, London, ON (United Kingdom); Fraass, B [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Bortfeld, T [Massachusetts General Hospital, Boston, MA (United States)

    2014-06-15

    Welcome and Introduction - Lawrence N. Rothenberg This symposium is one a continuing series of presentations at AAPM Annual Meetings on the historical aspects of medical physics, radiology, and radiation oncology that have been organized by the AAPM History Committee. Information on previous presentations including “Early Developments in Teletherapy” (Indianapolis 2013), “Historical Aspects of Cross-Sectional Imaging” (Charlotte 2012), “Historical Aspects of Brachytherapy” (Vancouver 2011), “50 Years of Women in Medical Physics” (Houston 2008), and “Roentgen's Early Investigations” (Minneapolis 2007) can be found in the Education Section of the AAPM Website. The Austin 2014 History Symposium will be on “Evolution of Radiation Treatment Planning.” Overview - Radhe Mohan Treatment planning is one of the most critical components in the chain of radiation therapy of cancers. Treatment plans of today contain a wide variety of sophisticated information conveying the potential clinical effectiveness of the designed treatment to practitioners. Examples of such information include dose distributions superimposed on three- or even four-dimensional anatomic images; dose volume histograms, dose, dose-volume and dose-response indices for anatomic structures of interest; etc. These data are used for evaluating treatment plans and for making treatment decisions. The current state-of-the-art has evolved from the 1940s era when the dose to the tumor and normal tissues was estimated approximately by manual means. However, the symposium will cover the history of the field from the late-1950's, when computers were first introduced for treatment planning, to the present state involving the use of high performance computing and advanced multi-dimensional anatomic, functional and biological imaging, focusing only on external beam treatment planning. The symposium will start with a general overview of the treatment planning process including imaging

  12. [Endodontically treated teeth. Success--failure. Endorestorative treatment plan].

    Science.gov (United States)

    Zabalegui, B

    1990-01-01

    More and more often the general dentist is finding the presence of endodontically treated teeth during his treatment planning procedure. He has to ask himself if the endo-treated tooth functions and will continue to function function successfully, when deciding which final endo-restorative procedure to apply. For this reason the dentist or the endodontist with whom he works should clinically evaluate these teeth, establish a diagnostic criteria of their success or failure and a treatment plan according to the prognosis. The purpose of this article is to offer an organized clinical view of the steps to follow when evaluating an endodontically treated tooth and how to establish a final endo-restorative plan.

  13. Treatment planning for MLC based robotic radiosurgery for brain metastases: plan comparison with circular fields and suggestions for planning strategies

    Directory of Open Access Journals (Sweden)

    Schmitt Daniela

    2017-09-01

    Full Text Available To evaluate the possible range of application of the new InCise2 MLC for the CyberKnife M6 system in brain radiosurgery, a plan comparison was made for 10 brain metastases sized between 1.5 and 9cm3 in 10 patients treated in a single fraction each. The target volumes consist of a PTV derived by expanding the GTV by 1mm and were chosen to have diversity in the cohort regarding regularity of shape, location and the structures needed to be blocked for beam transmission in the vicinity. For each case, two treatment plans were optimized: one using the MLC and one using the IRIS-collimator providing variable circular fields. Plan re-quirements were: dose prescription to the 70% isodose line (18 or 20Gy, 100% GTV coverage, ≥98% PTV coverage, undisturbed central high dose region (95% of maximum dose and a conformity index as low as possible. Plan com-parison parameters were: conformity index (CI, high-dose gradient index (GIH, low-dose gradient index (GIL, total number of monitor units (MU and expected treatment time (TT. For all cases, clinically acceptable plans could be gen-erated with the following results (mean±SD for CI, GIH, GIL, MU and TT, respectively for the MLC plans: 1.09±0.03, 2.77±0.26, 2.61±0.08, 4514±830MU and 27±5min and for the IRIS plans: 1.05±0.01, 3.00±0.35, 2.46±0.08, 8557±1335MU and 42±7min. In summary, the MLC plans were on average less conformal and had a shallower dose gradient in the low dose region, but a steeper dose gradient in the high dose region. This is accompanied by a smaller vol-ume receiving 10Gy. A plan by plan comparison shows that usage of the MLC can spare about one half of the MUs and one third of treatment time. From these experiences and results suggestions for MLC planning strategy can be de-duced.

  14. Savannah River Site approved site treatment plan, 2000 annual update

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, B.

    2000-04-20

    The Compliance Plan Volume (Volume 1) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions. Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume 2) and is provided for information.

  15. Metastatic spinal cord syndromes: imaging appearances and treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Abdi, S. [Department of Radiology, Nottingham City Hospital, Nottingham (United Kingdom)]. E-mail: shahramabdi@hotmail.com; Adams, C.I. [Centre for Spinal Studies and Surgery, Queen' s Medical Centre, University Hospital, Nottingham (United Kingdom); Foweraker, K.L. [Department of Oncology, Nottingham City Hospital, Nottingham (United Kingdom); O' Connor, A. [Department of Radiology, Nottingham City Hospital, Nottingham (United Kingdom)

    2005-06-01

    Metastatic spinal cord syndromes usually result from neural compression by adjacent vertebral disease but are occasionally caused by intradural or intramedullary disease. MRI is the most accurate method for evaluation of such syndromes. Knowledge of the relevant imaging appearances and therapeutic options enables the radiologist to make an accurate assessment of the extent of disease and contribute information relevant to treatment planning.

  16. Savannah River Site Approved Site Treatment Plan, 1998 Annual Update

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, B.

    1999-04-20

    The Compliance Plan Volume (Volume I) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions. Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume II) and is provided for information.

  17. Interocclusal Registration for Diagnosis and Treatment Planning for ...

    African Journals Online (AJOL)

    2017-09-14

    Sep 14, 2017 ... records. The well-fitting appliance can be used to accurately mount implant cases with inadequate posterior support for diagnosis and treatment planning. This technique of interocclusal registration has the advantages of accurate mounting, preservation of materials and financial expenses, and reduction of ...

  18. Incorrect dosimetric leaf separation in IMRT and VMAT treatment planning

    DEFF Research Database (Denmark)

    Sjölin, Maria; Edmund, Jens Morgenthaler

    2016-01-01

    PURPOSE: Dynamic treatment planning algorithms use a dosimetric leaf separation (DLS) parameter to model the multi-leaf collimator (MLC) characteristics. Here, we quantify the dosimetric impact of an incorrect DLS parameter and investigate whether common pretreatment quality assurance (QA) methods...

  19. 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...

  20. A non-voxel-based broad-beam (NVBB) framework for IMRT treatment planning.

    Science.gov (United States)

    Lu, Weiguo

    2010-12-07

    We present a novel framework that enables very large scale intensity-modulated radiation therapy (IMRT) planning in limited computation resources with improvements in cost, plan quality and planning throughput. Current IMRT optimization uses a voxel-based beamlet superposition (VBS) framework that requires pre-calculation and storage of a large amount of beamlet data, resulting in large temporal and spatial complexity. We developed a non-voxel-based broad-beam (NVBB) framework for IMRT capable of direct treatment parameter optimization (DTPO). In this framework, both objective function and derivative are evaluated based on the continuous viewpoint, abandoning 'voxel' and 'beamlet' representations. Thus pre-calculation and storage of beamlets are no longer needed. The NVBB framework has linear complexities (O(N(3))) in both space and time. The low memory, full computation and data parallelization nature of the framework render its efficient implementation on the graphic processing unit (GPU). We implemented the NVBB framework and incorporated it with the TomoTherapy treatment planning system (TPS). The new TPS runs on a single workstation with one GPU card (NVBB-GPU). Extensive verification/validation tests were performed in house and via third parties. Benchmarks on dose accuracy, plan quality and throughput were compared with the commercial TomoTherapy TPS that is based on the VBS framework and uses a computer cluster with 14 nodes (VBS-cluster). For all tests, the dose accuracy of these two TPSs is comparable (within 1%). Plan qualities were comparable with no clinically significant difference for most cases except that superior target uniformity was seen in the NVBB-GPU for some cases. However, the planning time using the NVBB-GPU was reduced many folds over the VBS-cluster. In conclusion, we developed a novel NVBB framework for IMRT optimization. The continuous viewpoint and DTPO nature of the algorithm eliminate the need for beamlets and lead to better plan

  1. Maintenance hormonal therapy after treatment with medroxyprogesterone acetate for patients with atypical polypoid adenomyoma.

    Science.gov (United States)

    Nomura, Hidetaka; Sugiyama, Yuko; Tanigawa, Terumi; Matoda, Maki; Okamoto, Sanshiro; Omatsu, Kohei; Kanao, Hiroyuki; Kato, Kazuyoshi; Utsugi, Kuniko; Takeshima, Nobuhiro

    2018-01-17

    As atypical polypoid adenomyoma (APA) has been reported to be a hormone-related tumor, we aimed to analyze the efficacy and safety of maintenance hormonal therapy after fertility-preserving treatment of these patients with medroxyprogesterone acetate (MPA). Data were retrospectively analyzed from patients with APA who were treated with a fertility-preserving regimen including MPA between October 2001 and December 2011. Eighteen patients were treated with MPA and 14 (77.8%) achieved either a complete or a partial response after the planned treatment. Five patients took progestin for maintenance therapy. Eighteen patients were treated for a mean observation period of 96.7 months. While taking the maintenance therapy, no patient had APA relapse. One patient developed well-differentiated endometrioid adenocarcinoma 18 months after she stopped taking maintenance progestin. Eleven patients without maintenance therapy underwent hysterectomy, andnine of them developed well-differentiated endometrial cancer. Through univariate analysis, there was a significant difference in time to hysterectomy between patients with and without maintenance therapy (P = 0.015). Through multivariate analysis, body mass index (BMI), menstrual status before protocol therapy, maintenance treatment, and pregnancy were found to be significantly associated with a lower risk of hysterectomy. No patient had a recurrence of APA after hysterectomy during the observation period (median, 54 months; range, 2-148 months). No patient showed progression while receiving hormonal therapy, including initial protocol therapy. Maintenance hormonal therapy after treatment with MPA was highly effective and safe, particularly in patients with BMI ≧24 kg/m2 and irregular menstruation cycle.

  2. History of music therapy treatment interventions for children with autism.

    Science.gov (United States)

    Reschke-Hernández, Alaine E

    2011-01-01

    The purpose of this paper is to provide a systematic review of the history of music therapy research and treatment of children with autism. Understanding such history is important in order to improve clinical efficacy and inform future research. This paper includes a history of autism diagnosis, reviews strengths and limitations of music therapy practice with children with autism from 1940-2009, and suggests direction for future music therapy research and clinical practice with this population. Literature was limited to the English language and obtained with the following search terms: autism, autistic, (early) infantile autism, child, therapeutic music, musical therapy, and music therapy. Table of contents from music therapy journals were searched, and reference lists from obtained articles were perused for additional articles. This historical review focused primarily on journal articles, however, books and book chapters that appeared to hold particular historical significance were also included.

  3. Comparing Cognitive Behavior Therapy, Problem Solving Therapy, and Treatment as Usual in a High Risk Population

    Science.gov (United States)

    Stewart, Carment D.; Quinn, Andrea; Plever, Sally; Emmerson, Brett

    2009-01-01

    Cognitive behavior therapy (CBT), problem-solving therapy (PST), or treatment as usual (TAU) were compared in the management of suicide attempters. Participants completed the Beck Hopelessness Scale, Beck Scale for Suicidal Ideation, Social Problem-Solving Inventory, and Client Satisfaction Questionnaire at pre- and posttreatment. Both CBT and PST…

  4. [Treatment of removable partial dentures. 1. Legislation, rules of conduct, care plan and treatment plan

    NARCIS (Netherlands)

    Witter, D.J.; Brands, W.G.; Barl, J.C.; Creugers, N.H.J.

    2011-01-01

    An invasive treatment, such as the treatment involving a removable partial denture, requires a well-structured approach. Regulations governing the communication between a healthcare professional and a patient in the Netherlands can be found in the Dutch Medical Treatment Act and the Rules of Conduct

  5. A novel conformity index for intensity modulated radiation therapy plan evaluation.

    Science.gov (United States)

    Cheung, Fion W K; Law, Maria Y Y

    2012-09-01

    Intensity modulated radiation therapy (IMRT) has gained popularity in the treatment of cancers. Manual evaluation of IMRT plans for head-and-neck cancers has been especially challenging necessitating efficient and objective assessment tools. In this work, the authors address this issue by developing a personalized conformity index (CI) for comparison of IMRT plans for head-and-neck cancers and evaluating its plan quality discerning power in comparison with other widely used CIs. A two-dimensional CI with dose and distance incorporated (CI(DD)) was developed using the MATLAB program language, to quantify the planning target volume (PTV) coverage. Valuable information contained in the digital imaging and communication in medicine (DICOM) RT objects were harvested for computation of each of the CI(DD) components. Apart from the dose penalty factor, a distance-based exponential function was employed by varying the penalty weight associated with the location of cold spots within the PTV. With the goal of deriving a customized penalty factor, the distances between individual pixel and its nearest PTV boundary was found. Using the exponential function, the impact of distance penalty was substantially larger for cold spots closer to the PTV centroid but petered out quickly wherever they were situated in the vicinity of PTV border. In order to evaluate the CI(DD) scoring system, three CT image data sets of nasopharyngeal carcinoma (NPC) patients were collected. Ten IMRT plans with degrading qualities were generated from each dataset and were ranked based on CI(DD) and other existing indices. The coefficient of variance was calculated for each dataset to compare the degree of variation. The CI(DD) scoring system that considered spatial importance of each voxel within the PTV was successfully developed. The results demonstrated that the CI(DD) including four discrete factors could provide accurate rankings of plan quality by examining the relative importance of each cold spot

  6. 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

  7. Comparison of Planning Quality and Efficiency Between Conventional and Knowledge-based Algorithms in Nasopharyngeal Cancer Patients Using Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Amy T.Y., E-mail: changty@ha.org.hk [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Hung, Albert W.M. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Cheung, Fion W.K.; Lee, Michael C.H. [Department of Medical Physics, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Chan, Oscar S.H. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Philips, Helen; Cheng, Yung-Tang [Varian Medical Systems, Palo Alto, California (United States); Ng, Wai-Tong [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong)

    2016-07-01

    Purpose: Intensity modulated radiation therapy (IMRT) is widely used to achieve a highly conformal dose and improve treatment outcome. However, plan quality and planning time are institute and planner dependent, and no standardized tool exists to recognize an optimal plan. RapidPlan, a knowledge-based algorithm, can generate constraints to assist optimization and produce high-quality IMRT plans. This report evaluated the quality and efficiency of using RapidPlan in nasopharyngeal carcinoma (NPC) IMRT planning. Methods and Materials: RapidPlan was configured using 79 radical IMRT plans for NPC; 20 consecutive NPC patients indicated for radical radiation therapy between October 2014 and May 2015 were then recruited to assess its performance. The ability of RapidPlan to produce acceptable plans was evaluated. For plans that could not achieve clinical acceptance, manual touch-up was performed. The IMRT plans produced without RapidPlan (manual plans) and with RapidPlan (RP-2 plans, including those with manual touch-up) were compared in terms of dosimetric quality and planning efficiency. Results: RapidPlan by itself could produce clinically acceptable plans for 9 of the 20 patients; manual touch-up increased the number of acceptable plans (RP-2 plans) to 19. The target dose coverage and conformity were very similar. No difference was found in the maximum dose to the brainstem and optic chiasm. RP-2 plans delivered a higher maximum dose to the spinal cord (46.4 Gy vs 43.9 Gy, P=.002) but a lower dose to the parotid (mean dose to right parotid, 37.3 Gy vs 45.4 Gy; left, 34.4 Gy vs 43.1 Gy; P<.001) and the right cochlea (mean dose, 48.6 Gy vs 52.6 Gy; P=.02). The total planning time for RP-2 plans was significantly less than that for manual plans (64 minutes vs 295 minutes, P<.001). Conclusions: This study shows that RapidPlan can significantly improve planning efficiency and produce quality IMRT plans for NPC patients.

  8. Impact of grid size on uniform scanning and IMPT plans in XiO treatment planning system for brain cancer.

    Science.gov (United States)

    Rana, Suresh; Zheng, Yuanshui

    2015-09-08

    The main purposes of this study are to: 1) evaluate the accuracy of XiO treatment planning system (TPS) for different dose calculation grid size based on head phan-tom measurements in uniform scanning proton therapy (USPT); and 2) compare the dosimetric results for various dose calculation grid sizes based on real computed tomography (CT) dataset of pediatric brain cancer treatment plans generated by USPT and intensity-modulated proton therapy (IMPT) techniques. For phantom study, we have utilized the anthropomorphic head proton phantom provided by Imaging and Radiation Oncology Core (IROC). The imaging, treatment planning, and beam delivery were carried out following the guidelines provided by the IROC. The USPT proton plan was generated in the XiO TPS, and dose calculations were performed for grid size ranged from 1 to 3 mm. The phantom containing thermoluminescent dosimeter (TLDs) and films was irradiated using uniform scanning proton beam. The irradiated TLDs were read by the IROC. The calculated doses from the XiO for different grid sizes were compared to the measured TLD doses provided by the IROC. Gamma evaluation was done by comparing calculated planar dose distribution of 3 mm grid size with measured planar dose distribution. Additionally, IMPT plan was generated based on the same CT dataset of the IROC phantom, and IMPT dose calculations were performed for grid size ranged from 1 to 3 mm. For comparative purpose, additional gamma analysis was done by comparing the planar dose distributions of standard grid size (3 mm) with that of other grid sizes (1, 1.5, 2, and 2.5 mm) for both the USPT and IMPT plans. For patient study, USPT plans of three pediatric brain cancer cases were selected. IMPT plans were generated for each of three pediatric cases. All patient treatment plans (USPT and IMPT) were generated in the XiO TPS for a total dose of 54 Gy (relative biological effectiveness [RBE]). Treatment plans (USPT and IMPT) of each case was recalculated for grid

  9. Comparison of Pencil beam, Collapsed cone and Monte-Carlo algorithm in radiotherapy treatment planning for 6 MV photon

    CERN Document Server

    Kim, Sung Jin; Kim, Sung Kyu

    2015-01-01

    Treatment planning system calculations in inhomogeneous regions may present significant inaccuracies due to loss of electronic equilibrium. In this study, three different dose calculation algorithms, pencil beam, collapsed cone, and Monte-Carlo, provided by our planning system were compared to assess their impact on the three-dimensional planning of lung and breast cases. A total of five breast and five lung cases were calculated using the PB, CC, and MC algorithms. Planning treatment volume and organs at risk delineation was performed according to our institutions protocols on the Oncentra MasterPlan image registration module, on 0.3 to 0.5 cm computed tomography slices taken under normal respiration conditions. Four intensity-modulated radiation therapy plans were calculated according to each algorithm for each patient. The plans were conducted on the Oncentra MasterPlan and CMS Monaco treatment planning systems, for 6 MV. The plans were compared in terms of the dose distribution in target, OAR volumes, and...

  10. A software tool for advanced MRgFUS prostate therapy planning and follow up

    Science.gov (United States)

    van Straaten, Dörte; Hoogenboom, Martijn; van Amerongen, Martinus J.; Weiler, Florian; Issawi, Jumana Al; Günther, Matthias; Fütterer, Jurgen; Jenne, Jürgen W.

    2017-03-01

    US guided HIFU/FUS ablation for the therapy of prostate cancer is a clinical established method, while MR guided HIFU/FUS applications for prostate recently started clinical evaluation. Even if MRI examination is an excellent diagnostic tool for prostate cancer, it is a time consuming procedure and not practicable within an MRgFUS therapy session. The aim of our ongoing work is to develop software to support therapy planning and post-therapy follow-up for MRgFUS on localized prostate cancer, based on multi-parametric MR protocols. The clinical workflow of diagnosis, therapy and follow-up of MR guided FUS on prostate cancer was deeply analyzed. Based on this, the image processing workflow was designed and all necessary components, e.g. GUI, viewer, registration tools etc. were defined and implemented. The software bases on MeVisLab with several implemented C++ modules for the image processing tasks. The developed software, called LTC (Local Therapy Control) will register and visualize automatically all images (T1w, T2w, DWI etc.) and ADC or perfusion maps gained from the diagnostic MRI session. This maximum of diagnostic information helps to segment all necessary ROIs, e.g. the tumor, for therapy planning. Final therapy planning will be performed based on these segmentation data in the following MRgFUS therapy session. In addition, the developed software should help to evaluate the therapy success, by synchronization and display of pre-therapeutic, therapy and follow-up image data including the therapy plan and thermal dose information. In this ongoing project, the first stand-alone prototype was completed and will be clinically evaluated.

  11. Laser therapy for prevention and treatment of pathologic excessive scars.

    Science.gov (United States)

    Jin, Rui; Huang, Xiaolu; Li, Hua; Yuan, Yuwen; Li, Bin; Cheng, Chen; Li, Qingfeng

    2013-12-01

    The management of hypertrophic scars and keloids remains a therapeutic challenge. Treatment regimens are currently based on clinical experience rather than substantiated evidence. Laser therapy is an emerging minimally invasive treatment that has recently gained attention. A meta-analysis was conducted to evaluate the effectiveness of various laser therapies. The pooled response rate, pooled standardized mean difference of Vancouver Scar Scale scores, scar height, erythema, and pliability were reported. Twenty-eight well-designed clinical trials with 919 patients were included in the meta-analysis. The overall response rate for laser therapy was 71 percent for scar prevention, 68 percent for hypertrophic scar treatment, and 72 percent for keloid treatment. The 585/595-nm pulsed-dye laser and 532-nm laser subgroups yielded the best responses among all laser systems. The pooled estimates of hypertrophic scar studies also showed that laser therapy reduced total Vancouver Scar Scale scores, scar height, and scar erythema of hypertrophic scars. Regression analyses of pulsed-dye laser therapy suggested that the optimal treatment interval is 5 to 6 weeks. In addition, the therapeutic effect of pulsed-dye laser therapy is better on patients with lower Fitzpatrick skin type scores. This study presents the first meta-analysis to confirm the efficacy and safety of laser therapy in hypertrophic scar management. The level of evidence for laser therapy as a keloid treatment is low. Further research is required to determine the mechanism of action for different laser systems and to examine the efficacy in quantifiable parameters, such as scar erythema, scar texture, degrees of symptom relief, recurrence rates, and adverse effects.

  12. Clinical Significance: a Therapeutic Approach Topsychological Assessment in Treatment Planning

    Directory of Open Access Journals (Sweden)

    Afolabi Olusegun Emmanuel

    2015-06-01

    Full Text Available Psychological assessment has long been reported as a key component of clinical psychology. This paper examines the complexities surrounding the clinical significance of therapeutic approach to treatment planning. To achieve this objective, the paper searched and used the PsycINFO and PubMed databases and the reference sections of chapters and journal articles to analysed, 1 a strong basis for the usage of therapeutic approach to psychological assessment in treatment plans, 2 explained the conceptual meaning of clinical significant change in therapeutic assessment, 3 answered some of the questions regarding practicability and the clinical significance of therapeutic approach to treatment plans, particularly during or before treatment, 4 linked therapeutic assessment to change in clients’ clinical impression, functioning and therapeutic needs 5 analysed the empirically documenting clinically significant change in therapeutic assessment. Finally, the study suggested that though therapeutic assessment is not sufficient for the systematic study of psychotherapy outcome and process, it is still consistent with both the layman and professional expectations regarding treatment outcome and also provides a precise method for classifying clients as ‘changed’ or ‘unchanged’ on the basis of clinical significance criteria.

  13. A treatment planning code for inverse planning and 3D optimization in hadrontherapy.

    Science.gov (United States)

    Bourhaleb, F; Marchetto, F; Attili, A; Pittà, G; Cirio, R; Donetti, M; Giordanengo, S; Givehchi, N; Iliescu, S; Krengli, M; La Rosa, A; Massai, D; Pecka, A; Pardo, J; Peroni, C

    2008-09-01

    The therapeutic use of protons and ions, especially carbon ions, is a new technique and a challenge to conform the dose to the target due to the energy deposition characteristics of hadron beams. An appropriate treatment planning system (TPS) is strictly necessary to take full advantage. We developed a TPS software, ANCOD++, for the evaluation of the optimal conformal dose. ANCOD++ is an analytical code using the voxel-scan technique as an active method to deliver the dose to the patient, and provides treatment plans with both proton and carbon ion beams. The iterative algorithm, coded in C++ and running on Unix/Linux platform, allows the determination of the best fluences of the individual beams to obtain an optimal physical dose distribution, delivering a maximum dose to the target volume and a minimum dose to critical structures. The TPS is supported by Monte Carlo simulations with the package GEANT3 to provide the necessary physical lookup tables and verify the optimized treatment plans. Dose verifications done by means of full Monte Carlo simulations show an overall good agreement with the treatment planning calculations. We stress the fact that the purpose of this work is the verification of the physical dose and a next work will be dedicated to the radiobiological evaluation of the equivalent biological dose.

  14. Treatment Planning Systems for BNCT Requirements and Peculiarities

    CERN Document Server

    Daquino, G G

    2003-01-01

    The main requirements and peculiarities expected from the BNCT-oriented treatment planning system (TPS) are summarized in this paper. The TPS is a software, which can be integrated or composed by several auxiliary programs. It plays important roles inside the whole treatment planning of the patient's organ in BNCT. However, the main goal is the simulation of the irradiation, in order to obtain the optimal configuration, in terms of neutron spectrum, patient positioning and dose distribution in the tumour and healthy tissues. The presence of neutrons increases the level of complexity, because much more nuclear reactions need to be monitored and properly calculated during the simulation of the patient's treatment. To this purposes several 3D geometry reconstruction techniques, generally based on the CT scanning data, are implemented and Monte Carlo codes are normally used. The TPSs are expected to show also the results (basically doses and fluences) in a proper format, such as isocurves (or isosurfaces) along t...

  15. New Immunosuppressive Therapies in Uveitis Treatment

    Directory of Open Access Journals (Sweden)

    Salvador Mérida

    2015-08-01

    Full Text Available Uveitis is an inflammatory process that initially starts in the uvea, but can also affect other adjacent eye structures, and is currently the fourth cause of blindness in developed countries. Corticoids are probably the most widespread treatment, but resorting to other immunosuppressive treatments is a frequent practice. Since the implication of different cytokines in uveitis has been well demonstrated, the majority of recent treatments for this disease include inhibitors or antibodies against these. Nevertheless, adequate treatment for each uveitis type entails a difficult therapeutic decision as no clear recommendations are found in the literature, despite the few protocolized clinical assays and many case-control studies done. This review aims to present, in order, the mechanisms and main indications of the most modern immunosuppressive drugs against cytokines.

  16. New Immunosuppressive Therapies in Uveitis Treatment

    Science.gov (United States)

    Mérida, Salvador; Palacios, Elena; Navea, Amparo; Bosch-Morell, Francisco

    2015-01-01

    Uveitis is an inflammatory process that initially starts in the uvea, but can also affect other adjacent eye structures, and is currently the fourth cause of blindness in developed countries. Corticoids are probably the most widespread treatment, but resorting to other immunosuppressive treatments is a frequent practice. Since the implication of different cytokines in uveitis has been well demonstrated, the majority of recent treatments for this disease include inhibitors or antibodies against these. Nevertheless, adequate treatment for each uveitis type entails a difficult therapeutic decision as no clear recommendations are found in the literature, despite the few protocolized clinical assays and many case-control studies done. This review aims to present, in order, the mechanisms and main indications of the most modern immunosuppressive drugs against cytokines. PMID:26270662

  17. Up-todate treatment with electroconvulsive therapy

    Directory of Open Access Journals (Sweden)

    Helena Korošec Jagodič

    2011-03-01

    Conclusions: Within the profession up-todate ECT is considered safe, effective and rapid working treatment for the severest forms of mental disorders. On the contrary, ECT is not performed in Slovenia. No professional reason exists that ECT would not be available in Slovenia. By Slovenian Mental Health Act ECT is considered as a special treatment option for mental disorders, but momentarily different barriers limit the availability of ECT to Slovenian patients, particularly to patients in acute illness conditions.

  18. Approved Site Treatment Plan, Volumes 1 and 2. Revision 4

    Energy Technology Data Exchange (ETDEWEB)

    Helmich, E.H.; Molen, G.; Noller, D.

    1996-03-22

    The US Department of Energy, Savannah River Operations Office (DOE-SR), has prepared the Site Treatment Plan (STP) for Savannah River Site (SRS) mixed wastes in accordance with RCRA Section 3021(b), and SCDHEC has approved the STP (except for certain offsite wastes) and issued an order enforcing the STP commitments in Volume 1. DOE-SR and SCDHEC agree that this STP fulfills the requirements contained in the FFCAct, RCRA Section 3021, and therefore, pursuant to Section 105(a) of the FFCAct (RCRA Section 3021(b)(5)), DOE`s requirements are to implement the plan for the development of treatment capacities and technologies pursuant to RCRA Section 3021. Emerging and new technologies not yet considered may be identified to manage waste more safely, effectively, and at lower cost than technologies currently identified in the plan. DOE will continue to evaluate and develop technologies that offer potential advantages in public acceptance, privatization, consolidation, risk abatement, performance, and life-cycle cost. Should technologies that offer such advantages be identified, DOE may request a revision/modification of the STP in accordance with the provisions of Consent Order 95-22-HW. The Compliance Plan Volume (Volume 1) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions (LDR). Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume 2) and is provided for information.

  19. Savannah River Site Approved Site Treatment Plan, 1998 Annual Update

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, B. [Westinghouse Savannah River Company, AIKEN, SC (United States); Berry, M.

    1998-03-01

    The U.S. Department of Energy, Savannah River Operations Office (DOE- SR),has prepared the Site Treatment Plan (STP) for Savannah River Site (SRS) mixed wastes in accordance with RCRA Section 3021(b), and SCDHEC has approved the STP (except for certain offsite wastes) and issued an order enforcing the STP commitments in Volume I. DOE-SR and SCDHEC agree that this STP fulfills the requirements contained in the FFCAct, RCRA Section 3021, and therefore,pursuant to Section 105(a) of the FFCAct (RCRA Section 3021(b)(5)), DOE`s requirements are to implement the plan for the development of treatment capacities and technologies pursuant to RCRA Section 3021.Emerging and new technologies not yet considered may be identified to manage waste more safely, effectively, and at lower cost than technologies currently identified in the plan. DOE will continue to evaluate and develop technologies that offer potential advantages in public acceptance, privatization, consolidation, risk abatement, performance, and life-cycle cost. Should technologies that offer such advantages be identified, DOE may request a revision/modification of the STP in accordance with the provisions of Consent Order 95-22-HW.The Compliance Plan Volume (Volume I) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions (LDR). Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume II) and is provided for information.

  20. Use dose bricks concept to implement nasopharyngeal carcinoma treatment planning.

    Science.gov (United States)

    Wu, Jia-Ming; Yu, Tsan-Jung; Yeh, Shyh-An; Chao, Pei-Ju; Huang, Chih-Jou; Lee, Tsair-Fwu

    2014-01-01

    A "dose bricks" concept has been used to implement nasopharyngeal carcinoma treatment plan; this method specializes particularly in the case with bell shape nasopharyngeal carcinoma case. Five noncoplanar fields were used to accomplish the dose bricks technique treatment plan. These five fields include (a) right superior anterior oblique (RSAO), (b) left superior anterior oblique (LSAO), (c) right anterior oblique (RAO), (d) left anterior oblique (LAO), and (e) superior inferior vertex (SIV). Nondivergence collimator central axis planes were used to create different abutting field edge while normal organs were blocked by multileaf collimators in this technique. The resulting 92% isodose curves encompassed the CTV, while maximum dose was about 115%. Approximately 50% volume of parotid glands obtained 10-15% of total dose and 50% volume of brain obtained less than 20% of total dose. Spinal cord receives only 5% from the scatter dose. Compared with IMRT, the expenditure of planning time and costing, "dose bricks" may after all be accepted as an optional implementation in nasopharyngeal carcinoma conformal treatment plan; furthermore, this method also fits the need of other nonhead and neck lesions if organ sparing and noncoplanar technique can be executed.

  1. Antipsychotic Polypharmacy in a Treatment-Refractory Schizophrenia Population Receiving Adjunctive Treatment With Electroconvulsive Therapy

    DEFF Research Database (Denmark)

    Kristensen, Diana; Hageman, Ida; Bauer, Jeanett

    2013-01-01

    Antipsychotic polypharmacy (APP) is frequent, but its pattern is unknown in treatment-refractory schizophrenia-spectrum patients receiving electroconvulsive therapy (ECT).......Antipsychotic polypharmacy (APP) is frequent, but its pattern is unknown in treatment-refractory schizophrenia-spectrum patients receiving electroconvulsive therapy (ECT)....

  2. Investigational therapies in the treatment of obesity.

    Science.gov (United States)

    Mancini, Marcio C; Halpern, Alfredo

    2006-08-01

    Obesity is a major public health concern and environmental factors are involved in its development. The hypothalamus is a primary site for the integration of signals for the regulation of energy homeostasis. Dysregulation of these pathways can lead to weight loss or gain. Some drugs in development can have favourable effects on body weight, acting on some of these pathways and leading to responses resulting in weight loss. Strategies for the management of weight reduction include exercise, diet, behavioural therapy, drug therapy and surgery. Investigational antiobesity medications can modulate energy homeostasis by stimulating catabolic or inhibiting anabolic pathways. Investigational drugs stimulating catabolic pathways consist of leptin, agonists of melanocortin receptor-4, 5-HT and dopamine; bupropion, growth hormone fragments, cholecystokinin subtype 1 receptor agonist, peptide YY3-36, oxyntomodulin, ciliary neurotrophic factor analogue, beta3-adrenergic receptor agonists, adiponectin derivatives and glucagon-like peptide-1. On the other hand, investigational drugs inhibiting anabolic pathways consist of the ghrelin receptor, neuropeptide Y receptor and melanin-concentrating hormone-1 antagonists; somatostatin analogues, peroxisome proliferator-activated receptor-gamma and -beta/delta antagonists, gastric emptying retardation agents, pancreatic lipase inhibitors, topiramate and cannabinoid-1 receptor antagonists. These differing approaches are reviewed and commented on in this article.

  3. Treatment outcome of directly observed therapy short-course for ...

    African Journals Online (AJOL)

    Treatment outcome of directly observed therapy short-course for pulmonary tuberculosis patients in a Nigerian tertiary institution: An eight-year review. ... Cases detected, sputum conversion and treatment outcome reports were analyzed using percentage. Results: A total of 177 pulmonary TB patients were seen during the ...

  4. Emerging Technologies in Autism Diagnosis, Therapy, Treatment, and Teaching

    Science.gov (United States)

    Nelson, Angela C.

    2014-01-01

    Autism Spectrum Disorder is the fastest growing developmental disability today. Autism is a syndrome with a diverse set of symptoms--rarely consistent across diagnosed individuals, and requiring a combination of therapies, educational approaches, and treatments. There is no known cure for autism. Instead treatment is left to educators and…

  5. ADHD and drug therapy: is it still a valid treatment?

    Science.gov (United States)

    Doggett, A Mark

    2004-03-01

    The purpose of this article is to discuss alternative treatments other than drug therapy for Attention-Deficit/Hyperactive Disorder (ADHD) in educational settings. There is an increasing body of knowledge that supports interventions for improving cognitive outcomes without the use of medication. The article explores the risks to ADHD children, shows the potential linkage between gifted children and ADHD, explores recent brain research, and examines various alternative treatment options. Information is presented on alternative treatments such as cognitive behavioral therapies, educational interventions, electroencephalograph (EEG) neuro-feedback, and diet.

  6. Plan comparison of volumetric-modulated arc therapy (RapidArc and conventional intensity-modulated radiation therapy (IMRT in anal canal cancer

    Directory of Open Access Journals (Sweden)

    Aillères Norbert

    2010-10-01

    Full Text Available Abstract Background To compare volumetric-modulated arc therapy (RapidArc plans with conventional intensity-modulated radiation therapy (IMRT plans in anal canal cancers. Methods Ten patients with anal canal carcinoma previously treated with IMRT in our institution were selected for this study. For each patient, three plans were generated with the planning CT scan: one using a fixed beam IMRT, and two plans using the RapidArc technique: a single (RA1 and a double (RA2 modulated arc therapy. The treatment plan was designed to deliver in one process with simultaneous integrated boost (SIB a dose of 59.4 Gy to the planning target volume (PTV2 based on the gross disease in a 1.8 Gy-daily fraction, 5 days a week. At the same time, the subclinical disease (PTV1 was planned to receive 49.5 Gy in a 1.5 Gy-daily fraction. Plans were normalized to 99% of the PTV2 that received 95% of the prescribed dose. Planning objectives were 95% of the PTV1 will receive 95% of the prescribed dose and no more than 2% of the PTV will receive more than 107%. Dose-volume histograms (DVH for the target volume and the organs at risk (bowel tract, bladder, iliac crests, femoral heads, genitalia/perineum, and healthy tissue were compared for these different techniques. Monitor units (MU and delivery treatment time were also reported. Results All plans achieved fulfilled objectives. Both IMRT and RA2 resulted in superior coverage of PTV than RA1 that was slightly inferior for conformity and homogeneity (p Conformity index (CI95% for the PTV2 was 1.15 ± 0.15 (RA2, 1.28 ± 0.22 (IMRT, and 1.79 ± 0.5 (RA1. Homogeneity (D5% - D95% for PTV2 was 3.21 ± 1.16 Gy (RA2, 2.98 ± 0.7 Gy (IMRT, and 4.3 ± 1.3 Gy (RA1. RapidArc showed to be superior to IMRT in terms of organ at risk sparing. For bowel tract, the mean dose was reduced of 4 Gy by RA2 compared to IMRT. Similar trends were observed for bladder, femoral heads, and genitalia. The DVH of iliac crests and healthy tissue resulted