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Olick-Gibson J, Cai B, Zhou S, Mutic S, Carter P, Hugo G, Zhang T. Feasibility study of surface motion tracking with millimeter wave technology during radiotherapy. Med Phys 2020; 47:1229-1237. [PMID: 31856302 DOI: 10.1002/mp.13980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/09/2019] [Accepted: 12/13/2019] [Indexed: 02/02/2023] Open
Abstract
PURPOSE Continuous monitoring of patient movement is crucial to administering safe radiation therapy (RT). Conventional optical approaches often cannot be used when the patient's surface is blocked by immobilization devices. Millimeter waves (mmWaves) are capable of penetrating nonconductive objects. In this study, we investigated using mmWave technology to monitor patient surface displacements, as well as breathing and cardiac phases, through clothing and body fixtures. METHODS A mmWave device was mounted inside the bore of a ring-based radiotherapy linear accelerator and pointed at a reflective surface on top of the couch. Measurements were obtained at displacements of 10, 7.5, 5.0, 2.5, and 1.0 mm at heights 100, 150, and 200 mm below isocenter. Submillimeter displacements were performed at a height of 200 mm. Additionally, millimeter and submillimeter displacements were measured with and without a gown and body mold placed between the surface and the sensor. The device was programmed to transmit chirp signals at 77-81 GHz. The subject's surface was detected by fast Fourier transform (FFT) of the reflected chirp signal within a rough range bin. Fine displacements within that range bin were calculated through phase extraction and phase demodulation. The displacement data were sent through two separate bandpass filters with passbands of 0.1-0.6 and 0.8-2.0 Hz to obtain the subject's breathing and cardiac waveforms, respectively. The breathing and cardiac measurements were compared to those of a Vernier Respiration Monitor Belt and an electrocardiogram (EKG), respectively, to assess validity. RESULTS The device was able to detect millimeter and submillimeter displacements as small as 0.1 mm, as well as monitor displacement with an accuracy within 1 mm in the presence of an obstructive object. The device's breathing and cardiac waveforms exhibited a strong phase correlation between the respiration monitor belt (ρ = 0.9156) and EKG (ρ = 0.7895), respectively. CONCLUSIONS The mmWave device can monitor surface displacements with an accuracy better than 0.1 mm without obstructions and better than 1 mm with obstructions. It can also provide real-time monitoring of breathing and cardiac waveforms simultaneously with high correlation with traditional respiratory and cardiac monitoring devices. Overall, mmWave technology demonstrates potential for motion monitoring in the field of radiation oncology.
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Affiliation(s)
- Joshua Olick-Gibson
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA
| | - Bin Cai
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA
| | - Shuang Zhou
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA
| | - Sasa Mutic
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA
| | - Paul Carter
- Office of Technology Management, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Geoff Hugo
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA
| | - Tiezhi Zhang
- Department of Radiation Oncology, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA
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Dipuglia A, Cameron M, Davis JA, Cornelius IM, Stevenson AW, Rosenfeld AB, Petasecca M, Corde S, Guatelli S, Lerch MLF. Validation of a Monte Carlo simulation for Microbeam Radiation Therapy on the Imaging and Medical Beamline at the Australian Synchrotron. Sci Rep 2019; 9:17696. [PMID: 31776395 PMCID: PMC6881291 DOI: 10.1038/s41598-019-53991-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 11/05/2019] [Indexed: 01/05/2023] Open
Abstract
Microbeam Radiation Therapy (MRT) is an emerging cancer treatment modality characterised by the use of high-intensity synchrotron-generated x-rays, spatially fractionated by a multi-slit collimator (MSC), to ablate target tumours. The implementation of an accurate treatment planning system, coupled with simulation tools that allow for independent verification of calculated dose distributions are required to ensure optimal treatment outcomes via reliable dose delivery. In this article we present data from the first Geant4 Monte Carlo radiation transport model of the Imaging and Medical Beamline at the Australian Synchrotron. We have developed the model for use as an independent verification tool for experiments in one of three MRT delivery rooms and therefore compare simulation results with equivalent experimental data. The normalised x-ray spectra produced by the Geant4 model and a previously validated analytical model, SPEC, showed very good agreement using wiggler magnetic field strengths of 2 and 3 T. However, the validity of absolute photon flux at the plane of the Phase Space File (PSF) for a fixed number of simulated electrons was unable to be established. This work shows a possible limitation of the G4SynchrotronRadiation process to model synchrotron radiation when using a variable magnetic field. To account for this limitation, experimentally derived normalisation factors for each wiggler field strength determined under reference conditions were implemented. Experimentally measured broadbeam and microbeam dose distributions within a Gammex RMI457 Solid Water® phantom were compared to simulated distributions generated by the Geant4 model. Simulated and measured broadbeam dose distributions agreed within 3% for all investigated configurations and measured depths. Agreement between the simulated and measured microbeam dose distributions agreed within 5% for all investigated configurations and measured depths.
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Affiliation(s)
- Andrew Dipuglia
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Matthew Cameron
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Jeremy A Davis
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Iwan M Cornelius
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Andrew W Stevenson
- CSIRO, Clayton, 3168, Australia
- Imaging and Medical Beamline, ANSTO/Australian Synchrotron, Melbourne, 3168, Australia
| | - Anatoly B Rosenfeld
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Marco Petasecca
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Stéphanie Corde
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
- Department of Radiation Oncology, Prince of Wales Hospital, Randwick, 2031, Australia
| | - Susanna Guatelli
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia
| | - Michael L F Lerch
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, 2522, Australia.
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Abstract
Hadrontherapy was born in 1938, when neutron beams were used in cancer therapy, but it has become an accepted therapeutical modality only in the last five years. Fast neutrons are still in use, even if their limitations are now apparent. Charged hadron beams are more favorable, since the largest specific energy deposition occurs at the end of their range in matter. The most used hadrons are at present protons and carbon ions. Both allow a dose deposition which conforms to the tumour target. Radiobiological experiments and the results of the first clinical trials indicate that carbon ions have, on top of this macroscopic property, a different way of interacting with cells at the microscopic level. There are thus solid hopes to use carbon beams of about 4500 MeV to control tumours which are radioresistant both to X-rays and protons. After discussing these macroscopic and microscopic properties of hadrontherapy, the hospital-based facilities, running or under construction, are reviewed. The conclusion is that, while in USA and Japan twelve of these centres will be running around the year 2001, in Europe very little is foreseen to use hadrontherapy to treat deep-seated tumours. The most advanced programme is the Italian one, which is described in the last Sections of the report. The main activities concern the construction, near Milano, of a centre for protons and carbon ions called CNAO (National Centre for Oncological Hadrontherapy) and the development of new type of proton accelerators. The Istituto Superiore di Sanità in Rome obtained the initial financing for constructing, in collaboration with ENEA, a 3 GHz linac, which eventually will accelerate protons to 200 MeV, so as to allow deep protontherapy. These, and other hadrontherapy centres in Italy and Europe, will be connected with oncology centres, hospitals and clinics by a multimedial network called RITA, so that before referral each patient's case can be discussed directly by doctors, even located far away, with the experts sitting in the hadrontherapy centres.
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Affiliation(s)
- U Amaldi
- CERN, European Organization for Nuclear Research, Geneva, Switzerland
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4
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Abstract
In the history of external beam radiotherapy, the trend for a better conformation as well as for a higher biological efficiency has been the driving force for the improvement of clinical results. However, these two goals had to be followed with separate types of radiation, i.e. photons and neutrons, and could not be combined. For the first time being, beams of heavy ions like carbon offer the possibility to combine both advantageous properties: better targeting and higher biological efficiency. Particle beams have an inverse depth dose profile, with a maximum dose in the deep seated tumor, a finite range, small lateral scattering, and a drastically increased biological efficiency in the tumor. These properties maximize the deletion effects on tumor cells. In addition, particle beams can be directed precisely in the limit of one or two millimeters, and can be monitored using positron emission tomography (PET) with the same precision. In the following paper the conditions are given that are necessary to translate these properties into clinical routine.
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Affiliation(s)
- G Kraft
- Gesellschaft für Schwerionenforschung Biophysik, Darmstadt, Germany.
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Bartzsch S, Cummings C, Eismann S, Oelfke U. A preclinical microbeam facility with a conventional x-ray tube. Med Phys 2016; 43:6301. [PMID: 27908159 PMCID: PMC5965367 DOI: 10.1118/1.4966032] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/22/2016] [Accepted: 10/11/2016] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Microbeam radiation therapy is an innovative treatment approach in radiation therapy that uses arrays of a few tens of micrometer wide and a few hundreds of micrometer spaced planar x-ray beams as treatment fields. In preclinical studies these fields efficiently eradicated tumors while normal tissue could effectively be spared. However, development and clinical application of microbeam radiation therapy is impeded by a lack of suitable small scale sources. Until now, only large synchrotrons provide appropriate beam properties for the production of microbeams. METHODS In this work, a conventional x-ray tube with a small focal spot and a specially designed collimator are used to produce microbeams for preclinical research. The applicability of the developed source is demonstrated in a pilot in vitro experiment. The properties of the produced radiation field are characterized by radiochromic film dosimetry. RESULTS 50 μm wide and 400 μm spaced microbeams were produced in a 20 × 20 mm2 sized microbeam field. The peak to valley dose ratio ranged from 15.5 to 30, which is comparable to values obtained at synchrotrons. A dose rate of up to 300 mGy/s was achieved in the microbeam peaks. Analysis of DNA double strand repair and cell cycle distribution after in vitro exposures of pancreatic cancer cells (Panc1) at the x-ray tube and the European Synchrotron leads to similar results. In particular, a reduced G2 cell cycle arrest is observed in cells in the microbeam peak region. CONCLUSIONS At its current stage, the source is restricted to in vitro applications. However, moderate modifications of the setup may soon allow in vivo research in mice and rats.
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Affiliation(s)
- Stefan Bartzsch
- Institute of Cancer Research, 15 Cotswold Road, Belmont Sutton, Surrey SM2 5NG, United Kingdom
| | - Craig Cummings
- Institute of Cancer Research, 15 Cotswold Road, Belmont Sutton, Surrey SM2 5NG, United Kingdom
| | - Stephan Eismann
- Department of Physics and Astronomy, University of Heidelberg, Grabengasse 1, 69117 Heidelberg, Germany
| | - Uwe Oelfke
- Institute of Cancer Research, 15 Cotswold Road, Belmont Sutton, Surrey SM2 5NG, United Kingdom
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Teh BS, Paulino AC, Lu HH, Chiu JK, Richardson S, Chiang S, Amato R, Butler EB, Bloch C. Versatility of the Novalis System to Deliver Image-Guided Stereotactic Body Radiation Therapy (SBRT) for Various Anatomical Sites. Technol Cancer Res Treat 2016; 6:347-54. [PMID: 17668943 DOI: 10.1177/153303460700600412] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) programs to treat brain tumors were implemented when we first acquired the Brainlab Novalis system in 2003. Two years later, we started an extra-cranial stereotactic radio-ablation or more appropriately a stereotactic body radiation therapy (SBRT) program using the Brainlab Novalis image-guided system at The Methodist Hospital in Houston, Texas. We hereby summarize our initial experience with this system in delivering image-guided SBRT to a total of 80 patients during our first year of clinical implementation, from February 2005 to January 2006. Over 100 lesions in more than 20 distinct anatomical sites were treated. These include all levels of spine from cervical, thoracic, lumbar, and sacral lesions. Spinal lesions encompass intramedullary, intradural, extradural, or osseous compartments. Also treated were lesions in other bony sites including orbit, clavicle, scapula, humerus, sternum, rib, femur, and pelvis (ilium, ischium, and pubis). Primary or metastatic lesions located in the head and neck, supraclavicular region, axilla, mediastinum, lung (both central and peripheral), abdominal wall, liver, kidney, para-aortic lymph nodes, prostate, and pelvis were also treated. In addition to primary radiotherapy, SBRT program using the Brainlab Novalis system allows re-irradiation for recurrence and “boost” after conventional treatment to various anatomical sites. Treating these sites safely and efficaciously requires knowledge in radiation tolerance, fraction size, total dose, biologically equivalent dose (BED), prior radiotherapy, detailed dose volume histograms (DVH) of normal tissues, and the radiosensitive/radioresistant nature of the tumor. Placement of radio-opaque markers (Visicoil, Radiomed) in anatomical sites not in close proximity to bony landmarks (e.g., kidney and liver) helps in measuring motion and providing image guidance during each treatment fraction. Tumor/organ motion data obtained using 4D-CT while the patient is immobilized in the body cast aids in planning treatment margin and determining the need for respiratory motion control, e.g., abdominal compressor, gating, or active breathing control. The inclusion of PET/CT to the Brainlab treatment planning system further refines the target delineation and possibly guides differential fraction size prescription and delivery. The majority of the patients tolerated the SBRT treatment well despite the longer daily treatment time when compared to that of conventional treatment. All patients achieved good pain relief after SBRT. Compared to conventional standard radiotherapy of lower daily fraction size, we observed that the patients achieved faster pain relief and possibly more durable symptom control. Very high local control with stable disease on imaging was observed post SBRT. Our initial experience shows that the Brainlab Novalis system is very versatile in delivering image-guided SBRT to various anatomical sites. This SBRT approach can be applied to either primary or metastatic lesions in the primary, “boost,” or re-irradiation settings. The understanding of fraction size, total dose, BED, and DVH of normal tissues is very important in the treatment planning. Appropriate use of immobilization devices, radio-opaque markers for image-guidance, 4D-CT for tumor/organ motion estimates, and fusion of planning CT scans with biological/functional imaging will further improve the planning and delivery of SBRT, hopefully leading to better treatment outcome.
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Affiliation(s)
- Bin S Teh
- Department of Radiation Oncology, Radiology, and Genito-urinary Oncology, The Methodist Hospital, The Methodist Hospital Research Institute and Baylor College of Medicine, 6565 Fannin St. MS 121-B, Houston, TX 77030, USA.
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7
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Sharp G, Fritscher KD, Pekar V, Peroni M, Shusharina N, Veeraraghavan H, Yang J. Vision 20/20: perspectives on automated image segmentation for radiotherapy. Med Phys 2014; 41:050902. [PMID: 24784366 PMCID: PMC4000389 DOI: 10.1118/1.4871620] [Citation(s) in RCA: 220] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 04/01/2014] [Accepted: 04/03/2014] [Indexed: 12/25/2022] Open
Abstract
Due to rapid advances in radiation therapy (RT), especially image guidance and treatment adaptation, a fast and accurate segmentation of medical images is a very important part of the treatment. Manual delineation of target volumes and organs at risk is still the standard routine for most clinics, even though it is time consuming and prone to intra- and interobserver variations. Automated segmentation methods seek to reduce delineation workload and unify the organ boundary definition. In this paper, the authors review the current autosegmentation methods particularly relevant for applications in RT. The authors outline the methods' strengths and limitations and propose strategies that could lead to wider acceptance of autosegmentation in routine clinical practice. The authors conclude that currently, autosegmentation technology in RT planning is an efficient tool for the clinicians to provide them with a good starting point for review and adjustment. Modern hardware platforms including GPUs allow most of the autosegmentation tasks to be done in a range of a few minutes. In the nearest future, improvements in CT-based autosegmentation tools will be achieved through standardization of imaging and contouring protocols. In the longer term, the authors expect a wider use of multimodality approaches and better understanding of correlation of imaging with biology and pathology.
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Affiliation(s)
- Gregory Sharp
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Karl D Fritscher
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114
| | | | - Marta Peroni
- Center for Proton Therapy, Paul Scherrer Institut, 5232 Villigen-PSI, Switzerland
| | - Nadya Shusharina
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Harini Veeraraghavan
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10065
| | - Jinzhong Yang
- Department of Radiation Physics, MD Anderson Cancer Center, Houston, Texas 77030
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8
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Abstract
Recent developments in radiotherapy therapy demand high computation powers to solve challenging problems in a timely fashion in a clinical environment. The graphics processing unit (GPU), as an emerging high-performance computing platform, has been introduced to radiotherapy. It is particularly attractive due to its high computational power, small size, and low cost for facility deployment and maintenance. Over the past few years, GPU-based high-performance computing in radiotherapy has experienced rapid developments. A tremendous amount of study has been conducted, in which large acceleration factors compared with the conventional CPU platform have been observed. In this paper, we will first give a brief introduction to the GPU hardware structure and programming model. We will then review the current applications of GPU in major imaging-related and therapy-related problems encountered in radiotherapy. A comparison of GPU with other platforms will also be presented.
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Affiliation(s)
- Xun Jia
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Peter Ziegenhein
- German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Steve B. Jiang
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Shinohara K, Kondoh T, Nariyama N, Fujita H, Washio M, Aoki Y. Optimization of X-ray microplanar beam radiation therapy for deep-seated tumors by a simulation study. J Xray Sci Technol 2014; 22:395-406. [PMID: 24865214 DOI: 10.3233/xst-140434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A Monte Carlo simulation was applied to study the energy dependence on the transverse dose distribution of microplanar beam radiation therapy (MRT) for deep-seated tumors. The distribution was found to be the peak (in-beam) dose and the decay from the edge of the beam down to the valley. The area below the same valley dose level (valley region) was decreased with the increase in the energy of X-rays at the same beam separation. To optimize the MRT, we made the following two assumptions: the therapeutic gain may be attributed to the efficient recovery of normal tissue caused by the beam separation; and a key factor for the efficient recovery of normal tissue depends on the area size of the valley region. Based on these assumptions and the results of the simulated dose distribution, we concluded that the optimum X-ray energy was in the range of 100-300 keV depending on the effective peak dose to the target tumors and/or tolerable surface dose. In addition, we proposed parameters to be studied for the optimization of MRT to deep-seated tumors.
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Affiliation(s)
- Kunio Shinohara
- Research Institute for Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Takeshi Kondoh
- Department of Neurosurgery, Kobe University Graduate School of Medicine, Kobe-shi, Hyogo, Japan Shinsuma General Hospital, Kobe-shi, Hyogo, Japan
| | - Nobuteru Nariyama
- Japan Synchrotron Radiation Research Institute, Sayo-gun, Hyogo, Japan
| | - Hajime Fujita
- Research Institute for Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Masakazu Washio
- Research Institute for Science and Engineering, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Yukimasa Aoki
- Medical Corporation YUKOUKAI Clinic, Funabashi-shi, Chiba, Japan
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10
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Tanabe E. [Innovation and the next generation radiotherapy system]. Igaku Butsuri 2013; 33:112-119. [PMID: 24893448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Innovation is the key to future success for Japan that is slowly falling behind. Industries targeted by the "Abenomics" growth strategy include healthcare and medicine. Since cancer is the leading cause of death in Japan, the development of a system that can detect and treat early stage cancers will be very valuable for patient QOL and reducing health care costs. Although the effectiveness of radiation therapy for treating early stage cancer is widely recognized, there has been no system to treat small, moving tumors with sub millimeter accuracy. A project supported by NEDO develops a "Next-Generation Radiation Therapy System" that uses high energy, narrow X-rays beams that can be accurately pinpointed deep inside the body. Performance testing of a prototype system is currently underway at the National Center for Global Health and Medicine in Tokyo.
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Fuse H, Sakae T, Terunuma T, Kamizawa S, Segawa T, Yoshimura Y, Yamanashi K, Sato M, Sakurai H. [Experience using the isocenter verification device in proton therapy equipment]. Igaku Butsuri 2013; 33:166-170. [PMID: 24893491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this study, we developed an isocenter verification device for use in proton therapy. Radiation and mechanical isocenters were verified for treatment equipment including room lasers, a digital radiography system and the beam axis of a rotational gantry. The special feature of this device is its ability to correlate the position of the three isocenters in one measurement and thus improve accuracy compared to the conventional method using three separate devices. The reproducibility of the method and the fluctuation of the position of the beam axis isocenter were both investigated using this device for almost a year. Monthly measurements of the isocenter position were acquired for two gantries and it was found that the fluctuation was +/- 0.10mm for the up-to-down direction and +/- 0.16mm for the right-to-left direction in Gantry 1 and was +/-0.14mm for the up-to-down direction and +/-0.18mm for the right-to-left direction in Gantry 2. We could be measured with a repeatability of +/-0.18 mm or less by using developed device for the relative positional relationship between each isocenters. Because we can confirm results in approximately 30 minutes, we can perform a quality control after a clinical practice.
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Luo G, Qi Z. [A novel serial port auto trigger system for MOSFET dose acquisition]. Zhongguo Yi Liao Qi Xie Za Zhi 2013; 37:27-29. [PMID: 23668038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
To synchronize the radiation of microSelectron-HDR (Nucletron afterloading machine) and measurement of MOSFET dose system, a trigger system based on interface circuit was designed and corresponding monitor and trigger program were developed on Qt platform. This interface and control system was tested and showed stable operate and reliable work. This adopted serial port detect technique may expand to trigger application of other medical devices.
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Affiliation(s)
- Guangwen Luo
- Radiation Oncology Department, Sun Yat-Sen University Cancer Center, Guangzhou, 510060
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13
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Mikołajczyk K, Piotrowski T. Development of cylindrical stepwedge phantom for routine quality controls of a helical tomotherapy machine. Phys Med 2013; 29:91-8. [PMID: 22209626 DOI: 10.1016/j.ejmp.2011.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 10/25/2011] [Accepted: 12/11/2011] [Indexed: 12/01/2022] Open
Affiliation(s)
- Krzysztof Mikołajczyk
- Department of Medical Physics, Greater Poland Cancer Centre, 15th Garbary Street, 61-866 Poznań, Poland.
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Fuse H, Sakae T, Terunuma T, Sato M, Aoki S. An isocenter detection and verification device for use in proton therapy. Rev Sci Instrum 2012; 83:125109. [PMID: 23278028 PMCID: PMC3537708 DOI: 10.1063/1.4771576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 11/27/2012] [Indexed: 06/01/2023]
Abstract
We developed a new device for isocenter detection and verification for use in proton therapy. This device can be used to confirm the isocenters of a room laser, a digital radiography system, and a rotational gantry. Agreement between the isocenters of a room laser and a digital radiography system was examined visually. We used the star-shots method for detecting and verifying the rotational gantry isocenter. The gafchromic film could be irradiated with this method using a 2 mm slitted 200 MeV proton beam. The isocenters of a room laser and digital radiography system were in good agreement. The size distribution of the isocenter by the star-shots method was <2 mm, which is the value recommended by the American Association of Physicists in Medicine Task Group 142. This new device can be used to evaluate comprehensive isocenter detection and verification for related equipment. Subsequent checking using this new device will decrease the uncertainty in measuring an isocenter. When using this device, the working time was significantly reduced to about 30 min, including preparation. These measurements should be useful for high accuracy daily treatments.
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Affiliation(s)
- H Fuse
- Proton Medical Research Center, University of Tsukuba, Tsukuba City 305-8576, Japan.
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15
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Fan Q, Nanduri A, Mazin S, Zhu L. Emission guided radiation therapy for lung and prostate cancers: a feasibility study on a digital patient. Med Phys 2012; 39:7140-52. [PMID: 23127105 PMCID: PMC3505203 DOI: 10.1118/1.4761951] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 09/22/2012] [Accepted: 10/03/2012] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Accurate tumor tracking remains a challenge in current radiation therapy. Many strategies including image guided radiation therapy alleviate the problem to certain extents. The authors propose a new modality called emission guided radiation therapy (EGRT) to accurately and directly track the tumor based on its biological signature. This work is to demonstrate the feasibility of EGRT under two clinical scenarios using a 4D digital patient model. METHODS EGRT uses lines of response (LOR's) from positron emission events to direct beamlets of therapeutic radiation through the emission sites inside a tumor. This is accomplished by a radiation delivery system consisting of a Linac and positron emission tomography (PET) detectors on a fast rotating closed-ring gantry. During the treatment of radiotracer-administrated cancer patients, PET detectors collect LOR's from tumor uptake sites and the Linac responds in nearly real-time with beamlets of radiation along the same LOR paths. Moving tumors are therefore treated with a high targeting accuracy. Based on the EGRT concept, the authors design a treatment method with additional modulation algorithms including attenuation correction and an integrated boost scheme. Performance is evaluated using simulations of a lung tumor case with 3D motion and a prostate tumor case with setup errors. The emission process is simulated by Geant4 Application for Tomographic Emission package (GATE) and Linac dose delivery is simulated using a voxel-based Monte Carlo algorithm (VMC++). RESULTS In the lung case with attenuation correction, compared to a conventional helical treatment, EGRT achieves a 41% relative increase in dose to 95% of the gross tumor volume (GTV) and a 55% increase to 50% of the GTV. All dose distributions are normalized for the same dose to the lung. In the prostate case with the integrated boost and no setup error, EGRT yields a 19% and 55% relative dose increase to 95% and 50% of the GTV, respectively, when all methods are normalized for the same dose to the rectum. In the prostate case with integrated boost where setup error is present, EGRT contributes a 21% and 52% relative dose increase to 95% and 50% of the GTV, respectively. CONCLUSIONS As a new radiation therapy modality with inherent tumor tracking, EGRT has the potential to substantially improve targeting in radiation therapy in the presence of intrafractional and interfractional motion.
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Affiliation(s)
- Qiyong Fan
- Georgia Institute of Technology, Atlanta, GA, USA
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16
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Abstract
Moving tumors, for example in the vicinity of the lungs, pose a challenging problem in radiotherapy, as healthy tissue should not be irradiated. Apart from gating approaches, one standard method is to irradiate the complete volume within which a tumor moves plus a safety margin containing a considerable volume of healthy tissue. This work deals with a system for tumor motion compensation using the HexaPOD® robotic treatment couch (Medical Intelligence GmbH, Schwabmünchen, Germany). The HexaPOD, carrying the patient during treatment, is instructed to perform translational movements such that the tumor motion, from the beams-eye view of the linear accelerator, is eliminated. The dynamics of the HexaPOD are characterized by time delays, saturations, and other non-linearities that make the design of control a challenging task. The focus of this work lies on two control methods for the HexaPOD that can be used for reference tracking. The first method uses a model predictive controller based on a model gained through system identification methods, and the second method uses a position control scheme useful for reference tracking. We compared the tracking performance of both methods in various experiments with real hardware using ideal reference trajectories, prerecorded patient trajectories, and human volunteers whose breathing motion was compensated by the system.
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Affiliation(s)
- Christian Hermann
- Department of Computer Science VII: Robotics and Telematics , University of Würzburg,D-97074 Würzburg , Germany.
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17
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Fassi A, Riboldi M, Forlani CF, Baroni G. Optical eye tracking system for noninvasive and automatic monitoring of eye position and movements in radiotherapy treatments of ocular tumors. Appl Opt 2012; 51:2441-2450. [PMID: 22614424 DOI: 10.1364/ao.51.002441] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/06/2012] [Indexed: 06/01/2023]
Abstract
A noninvasive eye tracking system based on infrared 3-D video-oculographic techniques is proposed for the automatic monitoring of eye position and orientation in external beam radiotherapy of ocular tumors. The presented method can be applied for the real-time estimation of lesion position and tumor-beam misalignments, allowing automatic patient setup and eye movement gated treatments. A prototypal eye tracker was developed and tested on five subjects, achieving gaze estimation errors of 0.5° and eye monitoring frequencies of 125 Hz. The proposed application can potentially improve quality and efficacy of ocular radiotherapy treatments, currently based on invasive, qualitative, and manual control procedures.
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Affiliation(s)
- Aurora Fassi
- Department of Bioengineering, Politecnico di Milano, 20133 Milano, Italy.
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Brady Z, Einsiedel P. A computed tomography (CT) wish list, from a medical physicist's perspective. Australas Phys Eng Sci Med 2012; 35:1-5. [PMID: 22434408 DOI: 10.1007/s13246-012-0133-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Yamada M, Ohkubo M, Kayugawa A, Yamada H, Matsuura M, Miura T, Kusumoto T. [Electronic portal imaging device (EPID) portal image filtering for simplifying registration on radiation therapy]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2012; 68:593-601. [PMID: 22687904 DOI: 10.6009/jjrt.2012_jsrt_68.5.593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A simple method for improving the quality of electronic portal imaging device (EPID) portal images was proposed for the reduction of the burden on the registration between digital reconstruction radiography (DRR) and EPID portal images in radiation therapy. Conventional image filtering techniques in the spatial-frequency domain are applied to the proposed method. While a band-pass filter (BPF) is employed to extract spatial-frequency components included in the bone edge, a high-pass filter (HPF) is employed to obtain the effect corresponding to the general dynamic range compression. The band-pass filtered image is weighted by a parameter for adjusting the bone edge enhancement, and is added to the high-pass filtered image. This method was applied to the portal images in the neck region. In the image obtained by the proposed filtering, the bone edge was clearly observed. In addition, soft tissue structures were identified in the same display settings (window level/width; WL/WW) as the bone edge observation; that is, the adjustment of the display settings was not required for the observation of each object. These results suggested that both bone edge enhancement and dynamic range compression would be achieved successfully. It was estimated that the images obtained by the proposed method were more appropriate for the registration than conventional portal images, in 47 times registrations of 50 times in total (the registrations by five radiological technologists in ten patients). The proposed method was concluded to be useful for improving the quality of portal images, enabling the efficient registration.
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20
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Yanano N, Fujibuchi T. [Method for evaluating the mechanical isocenter of the gantry of a radiotherapy machine with motion picture trace analysis software]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2012; 68:1499-1507. [PMID: 23171772 DOI: 10.6009/jjrt.2012_jsrt_68.11.1499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In recent years, development of advanced radiotherapy technology has resulted in an improvement in radiotherapy. Although the radiotherapy system has improved, the effect of the gap, the gyration center, and distortion of the rotation orbit cannot be neglected. Therefore, a verification method for a geometrical isocenter and rotation orbit in a three-dimension (3D) space is required. We developed a verification method for determination of the geometrical isocenter. In this method, the rotation of the gantry that applied the measured target from two directions was imaged and analyzed using animation pursuit analysis software. The measurement targets were pursued by analysis, and the rotation orbit of the target was visually evaluated from obtained coordinates and displacement distance. The gyration center in 3D space was calculated from pursued coordinates and compared with the intersection in the side laser and crosshair. In this verification method, the rotation orbit and geometrical isocenter in the 3D space were confirmed, and visually evaluated. Thus, this method was effective in verifying the geometrical isocenter by solving the problem of the measurement precision and reproducibility.
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Affiliation(s)
- Nobutaka Yanano
- Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, School of Health Sciences
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21
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Robertson D, Polf JC, Peterson SW, Gillin MT, Beddar S. Material efficiency studies for a Compton camera designed to measure characteristic prompt gamma rays emitted during proton beam radiotherapy. Phys Med Biol 2011; 56:3047-59. [PMID: 21508442 PMCID: PMC3087185 DOI: 10.1088/0031-9155/56/10/010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Prompt gamma rays emitted from biological tissues during proton irradiation carry dosimetric and spectroscopic information that can assist with treatment verification and provide an indication of the biological response of the irradiated tissues. Compton cameras are capable of determining the origin and energy of gamma rays. However, prompt gamma monitoring during proton therapy requires new Compton camera designs that perform well at the high gamma energies produced when tissues are bombarded with therapeutic protons. In this study we optimize the materials and geometry of a three-stage Compton camera for prompt gamma detection and calculate the theoretical efficiency of such a detector. The materials evaluated in this study include germanium, bismuth germanate (BGO), NaI, xenon, silicon and lanthanum bromide (LaBr(3)). For each material, the dimensions of each detector stage were optimized to produce the maximum number of relevant interactions. These results were used to predict the efficiency of various multi-material cameras. The theoretical detection efficiencies of the most promising multi-material cameras were then calculated for the photons emitted from a tissue-equivalent phantom irradiated by therapeutic proton beams ranging from 50 to 250 MeV. The optimized detector stages had a lateral extent of 10 × 10 cm(2) with the thickness of the initial two stages dependent on the detector material. The thickness of the third stage was fixed at 10 cm regardless of material. The most efficient single-material cameras were composed of germanium (3 cm) and BGO (2.5 cm). These cameras exhibited efficiencies of 1.15 × 10(-4) and 9.58 × 10(-5) per incident proton, respectively. The most efficient multi-material camera design consisted of two initial stages of germanium (3 cm) and a final stage of BGO, resulting in a theoretical efficiency of 1.26 × 10(-4) per incident proton.
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Affiliation(s)
- Daniel Robertson
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Unit 94, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Jerimy C Polf
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Unit 94, Houston, TX 77030, USA
| | - Steve W Peterson
- Department of Physics, University of Cape Town, Rondebosch 7701, South Africa
| | - Michael T Gillin
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Unit 94, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Sam Beddar
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Unit 94, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
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Buzurovic I, Yu Y, Podder TK. Active Tracking and Dynamic Dose Delivery for robotic couch in radiation therapy. Annu Int Conf IEEE Eng Med Biol Soc 2011; 2011:2156-2159. [PMID: 22254765 DOI: 10.1109/iembs.2011.6090404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Precise and accurate dose delivery is critically important in external beam radiation therapy. In many cases target-volumes are stationary, but the problem arises when the tumors move significantly due to cardiac and respiratory motions. This is a case for tumors in lung, esophagus, pancreas, liver, prostate, breast, and other organs in thoracic and abdominal regions. In the article we have described the Active Tracking and Dynamic Dose Delivery (ATDD) technique for real-time tumor motion compensation. In this approach, the robotic treatment table moves while delivering the radiation beam and compensates for breathing-induced tumor motion. Many parameters of the control system, such as patient mass or breathing pattern, are initially uncertain and may vary during the treatment. To solve these problems, feedforward adaptive control was adopted to minimize irradiation to healthy tissue and spare critical organs while ensuring prescribed radiation dose coverage to the target-volume.
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Affiliation(s)
- Ivan Buzurovic
- Thomas Jefferson University, Medical Physics Division, Philadelphia, PA, USA.
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Xu ZH, Liao FX, He ZQ, Ni Q. [PET and CT cross-modality medical image fusion based on out-location frame]. Nan Fang Yi Ke Da Xue Xue Bao 2010; 30:1304-1306. [PMID: 20584663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
OBJECTIVE To develop a new method of PET and CT cross-modality medical image fusion based on out-location frame. METHODS PET/CT cross-modality medical images were obtained based on the out-location frame and the external fiducial marker on the frame was used for rigid medical image registration. A variation model based on the wavelet transform was used for image fusion. RESULTS The CT images were displayed by grey scale and overlaid with the PET images displayed by chromatic scale to obtain the image after registration and fusion. CONCLUSION The method of external markers registration can be effective and accurate in achieving PET and CT image fusion.
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Affiliation(s)
- Zi-hai Xu
- Radiotherapy Center of PLA 303 Hospital, Nanning 530021, China
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24
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Tong D, Huang MW, Zhang JG, Feng HL, Li YS. [Clinical application of computer-aided design and rapid prototyping technique for radioactive seeds contained maxillary device]. Beijing Da Xue Xue Bao Yi Xue Ban 2010; 42:63-66. [PMID: 20140046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE To test a new method to manufacture a maxillary applicator containing radioactive seeds for brachytherapy of malignant neoplasms based on computer aided design (CAD) and rapid prototyping (RP). METHODS Six patients with maxillary malignancy which had eroded the inferior wall of orbit and skull base were included in this study. After excision of the tumors, head CT data of these patients were transmitted into the computer. Three-dimensional digital image of the patient's defected region was then obtained with special software processing based on Mimics 8.11 and Geomagic 7.0 and the resin cast of the defected region was manufactured by rapid prototyping. The elastic obturator was then made on this resin cast which can duplicate the undercut tissue of the defected region. After the obturator was completed, the radiotherapy plan was made. (125)I radioactive seeds were implanted into the tissues, and they were also implanted into the target area of the obturator which was used as a maxillary applicator at the same time. The number of radioactive seeds was then counted and the stability of radioactive seeds was determined by CT examination. All these 6 patients were followed-up for 12 months. RESULTS All the obturators had good retention and stability and fitted the designed target tissue very well. (125)I radioactive seeds in the form of the obturator applicator were stable. For all patients, the total number of radioactive seeds used was 189. Among them, 105 seeds, 55.6% of the total, were contained in obturator applicators. After the obturator applicators were used, the amount of radioactive seeds irradiating the target regions was significantly increased when compared with that of before. After follow-up of 12 months, there was no recurrence nor severe complications. CONCLUSION (125)I radioactive seeds contained maxillary applicator made by computer aided design and rapid prototyping can effectively improve the brachytherapy of (125)I when it is used for the post-operation radiotherapy of maxillary malignant tumors.
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Affiliation(s)
- Dai Tong
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
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25
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Abstract
The importance of exact patient positioning in radiation therapy increases with the ongoing improvements in irradiation planning and treatment. Therefore, new ways to overcome precision limitations of current positioning methods in fractionated treatment have to be found. The Department of Medical Physics at the German Cancer Research Centre (DKFZ) follows different video-based approaches to increase repositioning precision. In this context, the modular software framework FIVE (Fast Integrated Video-based Environment) has been designed and implemented. It is both hardware- and platform-independent and supports merging position data by integrating various computer-aided patient positioning methods. A highly precise optical tracking system and several subtraction imaging techniques have been realized as modules to supply basic video-based repositioning techniques. This paper describes the common framework architecture, the main software modules and their interfaces. An object-oriented software engineering process has been applied using the UML, C + + and the Qt library. The significance of the current framework prototype for the application in patient positioning as well as the extension to further application areas will be discussed. Particularly in experimental research, where special system adjustments are often necessary, the open design of the software allows problem-oriented extensions and adaptations.
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Affiliation(s)
- T Liebler
- German Cancer Research Centre (DKFZ), Department of Medical Physics, Im Neuenheimer Feld 280, D-69120, Heidelberg, Germany.
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26
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Abstract
We have investigated the dosimetric properties of a commercial kilovoltage cone beam computerised tomography (kV-CBCT) system. The kV-CBCT doses were measured in 16 and 32 cm diameter standard cylindrical Perspex computerised tomography (CT) and Rando anthropomorphic phantoms using 125 kVp and 1.0-2.0 mA s per projection. We also measured skin doses using thermoluminescence dosimeters placed on the skin surfaces of prostate cancer patients undergoing kV-kV image matching for daily set-up. The skin doses from kV-kV image matching of prostate cancer patients on the anterior and lateral skin surfaces ranged from 0.03 +/- 0.01 to 0.64 +/- 0.01 cGy depending on the beam filtration and technique factors employed. The mean doses on the Rando phantom ranged from 3.0 +/- 0.1 to 5.1 +/- 0.3 cGy for full-fan scans and from 3.8 +/- 0.1 to 6.6 +/- 0.2 cGy for half-fan scans using 125 kVp and 2 mA s per projection. The isocentre cone beam dose index (CBDI) in the 16 and 32 cm Perspex phantoms is 4.65 and 1.81 cGy, respectively (using a 0.6 cm(3) Capintec PR06C Farmer chamber) for full-fan scans, and the corresponding normalised CBDIs are 0.72 and 0.28 cGy/100 mA s, respectively. The mean weighted CBDIs are 4.93 and 2.14 cGy, and the normalised weighted CBDIs are 0.76 and 0.33 cGy/100 mA s for the 16 and 32 cm phantoms, respectively (full-fan scans). The normalised weighted CBDI for the half-fan scan is 0.41 cGy/100 mA s for the 32 cm diameter phantom. All measurements of the CBDI using the 0.6 cm(3) Farmer chamber are within 2-5% of measurements taken with the 100 mm CT chamber. The CBDI technique and definitions can be used to benchmark CBCT systems and to provide estimates of imaging doses to patients undergoing on-board imager (OBI)/CBCT image guided radiation therapy.
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Affiliation(s)
- Ernest K Osei
- Department of Medical Physics, Grand River Regional Cancer Center, Kitchener, Ontario, Canada
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28
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Sarkar V, Shi C, Rassiah-Szegedi P, Eng T, Diaz A, Papanikolaou N. A feasibility study on the use of digital tomosynthesis with individually-acquired megavoltage portal images for target localization. J BUON 2009; 14:103-108. [PMID: 19365878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
PURPOSE To determine the feasibility of using megavoltage (MV) images and digital tomosynthesis to determine the three dimensional (3D) localization of different objects. MATERIALS AND METHODS Different phantom geometries were imaged using an electronic portal imaging device and digital tomosynthesis was used to reconstruct tomograms. These were compared with corresponding computed tomography (CT) images. RESULTS While in-plane resolution of the tomograms was comparable as that of the CT images, definite out-of-plane (depth) localization was restricted to 5 mm. CONCLUSION The results confirm that it is possible to perform 3D localization of objects by using digital tomosynthesis for volumetric reconstructions from individually-acquired MV-quality portal images.
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Affiliation(s)
- V Sarkar
- Cancer Therapy and Research Center, University of Texas Health Science Center, San Antonio, TX, USA.
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29
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Romero P, Villafranca E, Rico M, Manterola A, Vila MT, Domínguez MA. [Clinical impact of image guided radiotherapy]. An Sist Sanit Navar 2009; 32 Suppl 2:33-37. [PMID: 19738657 DOI: 10.23938/assn.0179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Image guided radiotherapy (IGR) is a concept that encompasses the most modern way of administering radiotherapy treatment. The aim is to maximise the dose deposited in the target volume, minimising the dose in healthy organs. This would not be possible without the continuous development of technology and software, above all in the following areas: deformable image registration, replanning new treatments, real time image and calculation of accumulated dose. While the clinical impact is evident, little is said about the impact on the reorganisation of the Radiotherapy Oncology services. IGR supposes training all team members involved, with a training and a starting period. With the experience acquired, the time dedicated to each patient (in all stages of treatment: simulation, planning, starting out, systems for verifying position, on-line, off-line corrections, replanning, periodic clinical controls) is far higher than that required in conventional radiotherapy, which gives rise to new responsibilities and roles.
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Affiliation(s)
- P Romero
- Servicio de Oncología Radioterápica, Hospital de Navarra, Irunlarrea 3, Pamplona, Spain.
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Hungr N, Troccaz J, Zemiti N, Tripodi N. Design of an ultrasound-guided robotic brachytherapy needle-insertion system. Annu Int Conf IEEE Eng Med Biol Soc 2009; 2009:250-253. [PMID: 19964212 DOI: 10.1109/iembs.2009.5333801] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In this paper we describe a new robotic brachytherapy needle-insertion system that is designed to replace the template used in the manual technique. After a brief review of existing robotic systems, we describe the requirements that we based our design upon. A detailed description of the proposed system follows. Our design is capable of positioning and inclining a needle within the same workspace as the manual template. To help improve accuracy, the needle can be rotated about its axis during insertion into the prostate. The system can be mounted on existing steppers and also easily accommodates existing seed dispensers, such as the Mick Applicator.
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Gualdrini G, Tanner RJ, Agosteo S, Pola A, Bedogni R, Ferrari P, Lacoste V, Bordy JM, Chartier JL, de Carlan L, Gomez Ros JM, Grosswendt B, Kodeli I, Price RA, Rollet S, Schultz F, Siebert B, Terrissol M, Zankl M. Analysis of the CONRAD computational problems expressing only stochastic uncertainties: neutrons and protons. Radiat Prot Dosimetry 2008; 131:7-14. [PMID: 18782783 DOI: 10.1093/rpd/ncn241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Within the scope of CONRAD (A Coordinated Action for Radiation Dosimetry) Work Package 4 on Computational Dosimetry jointly collaborated with the other research actions on internal dosimetry, complex mixed radiation fields at workplaces and medical staff dosimetry. Besides these collaborative actions, WP4 promoted an international comparison on eight problems with their associated experimental data. A first set of three problems, the results of which are herewith summarised, dealt only with the expression of the stochastic uncertainties of the results: the analysis of the response function of a proton recoil telescope detector, the study of a Bonner sphere neutron spectrometer and the analysis of the neutron spectrum and dosimetric quantity H(p)(10) in a thermal neutron facility operated by IRSN Cadarache (the SIGMA facility). A second paper will summarise the results of the other five problems which dealt with the full uncertainty budget estimate. A third paper will present the results of a comparison on in vivo measurements of the (241)Am bone-seeker nuclide distributed in the knee. All the detailed papers will be presented in the WP4 Final Workshop Proceedings.
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Affiliation(s)
- G Gualdrini
- ENEA, Ente per le Nuove tecnologie, l'Energia e l'Ambiente, ION-IRP, Via dei Colli 16, I-40136 Bologna, Italy.
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de Carlan L, Price R, Chartier JL, Kodeli I, Siebert B, Henninger J, Posselt J, Gualdrini G, Agosteo S, Bedogni R, Bordy JM, Cassette P, Ferrari P, Gomez Ros JM, Grosswendt B, Lacoste V, Pola A, Rollet S, Schultz F, Simakov SP, Tanner R, Terrissol M, Zankl M. Analysis of computational problems expressing the overall uncertainties: photons, neutrons and electrons. Radiat Prot Dosimetry 2008; 131:15-23. [PMID: 18725380 DOI: 10.1093/rpd/ncn221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In the frame of the EU Coordination Action CONRAD (coordinated network for radiation dosimetry), WP4 was dedicated to work on computational dosimetry with an action entitled 'Uncertainty assessment in computational dosimetry: an intercomparison of approaches'. Participants attempted one or more of eight problems. This paper presents the results from problems 4-8-dealing with the overall uncertainty budget estimate; a short overview of each problem is presented together with a discussion of the most significant results and conclusions. The scope of the problems discussed here are: the study of a (137)Cs calibration irradiator; the manganese bath technique; the iron sphere experiment using neutron time-of-flight technique; the energy response of a RADFET detector and finally the sensitivity and uncertainty analysis for the recoil-proton telescope discussed in the companion paper.
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Affiliation(s)
- Loïc de Carlan
- Commissariat à l'Energie Atomique, Laboratoire National Henri Becquerel (CEA-LIST /DRT), 91191 Gif sur Yvette, France.
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33
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Affiliation(s)
- Dennis Cheek
- Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana 70809, USA.
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Jin JY, Yin FF, Tenn SE, Medin PM, Solberg TD. Use of the BrainLAB ExacTrac X-Ray 6D System in Image-Guided Radiotherapy. Med Dosim 2008; 33:124-34. [PMID: 18456164 DOI: 10.1016/j.meddos.2008.02.005] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Accepted: 02/29/2008] [Indexed: 11/16/2022]
Affiliation(s)
- Jian-Yue Jin
- Department of Radiation Oncology, Henry Ford Health System, Detroit, MI 48202, USA.
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Abstract
The goal of radiation therapy is to eradicate tumor stem cells while sparing healthy tissue. Therefore, the first aim must be to delineate tumor from healthy tissue. Advanced imaging techniques will enable one to reduce the uncertainty of microscopic extension of disease. Ultimately, advanced functional imaging systems correlated with image-registered pathological specimens will allow one to delineate disease extent from normal tissue at the tumor periphery. When it is not possible to determine the CTV margin with reasonable certainty, the margins must remain generous and conformal avoidance methodology could and should be deployed to spare critical normal structures. Of equal importance to defining the CTV is the need to guarantee that this target is indeed treated. For this purpose, image guidance using a variety of systems including portal images, ultrasound devices, and CT scanners at the time of treatment has been implemented. Some image-guided methods, portal images for instance, are more amenable for use with rigid structures such as encountered in the sinus whereas others like ultrasound or CT scanners are able to account for nonrigid setup variations. Several strategies for preventing organ motion from degrading the precision that radiotherapy offers have been described. In particular, a CT scan at the time of treatment delivery can also be used as the basis to reconstruct the dose received by the patient. Dose reconstruction will allow the dose just delivered to be superimposed on the pretreatment CT scan and will allow one to compare the reconstructed delivered dose distribution with the planned dose distribution to assess discrepancies between these. Furthermore, reconstruction of the delivered dose distributions holds the promise of allowing one to accumulate dose delivered to the tumor and normal structures on a fraction per fraction basis. This will ultimately allow for the determination of treatment-specific tumor control probabilities and normal tissue complication probabilities.
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Affiliation(s)
- Thomas Rockwell Mackie
- Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, USA
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Miszczyk L, Leszczyński W, Szczepanik K, Majewski W. [Comparison of two image guided radiation therapy (IGRT) methods used for prostate cancer patients--CBCT and 2D-2D kV]. Przegl Lek 2008; 65:315-320. [PMID: 19004227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The IGRT notion (image guided radiation therapy) comprises all techniques enabling checking and correction of patients position directly before or during an irradiation session. In last years they became a standard in radiotherapy due to decreasing of geographical misses. The aim of our study was a comparison of two IGRT techniques--CBCT and 2D-2D kV performed for prostate cancer patients and a comparison of two immobilization systems used for them. The performed analysis comprises 3582 2D-2D kV and 2110 CBCT IGRT measurements made for 85 prostate cancer patients. Patients were irradiated using thermoplastic masks and two kinds of immobilizing plates. One subgroup of patients was treated using leg supports and second one without them. Mean, maximum, minimum and standard deviation of absolute values of shifts (cm) measured using 2D-2D kV were 0.27, 0.0, 2.8 and 0.33 respectively. For CBCT these same values were 0.31, 0.0, 4.1 and 0.33. Mean, maximum, minimum and standard deviation of real shifts values (cm) measured using 2D-2D kV were -0.01, -2.5, 2.8 and 0.43 respectively. For CBCT these same values were 0.01, -4.1, 2.3 and 0.45. Comparison of shift absolute values distributions for whole analyzed group showed statistically significant difference (p=0.001) between 2D-2D kV and CBCT with higher mean for CBCT (0.31 vs 0.27) and equal standard deviations. Statistically significant difference (p=0.000...) between distributions of measurements in z axis was found (for 2D-2D kV mean 0.16, SD=0.21, for CBCT mean 0.25, SD=0.25). Comparison of absolute shifts values distributions revealed significant difference for CBCT, for two immobilization plates--in x (p=0.001) and y axis (p=0.007). For the small plate in x axis mean was 0.22 (SD=0.2), and for the large one (with an integrated head support) 0.17 (SD=0.2). Comparison of absolute shifts values for sub- groups created dependently on the leg support use, showed significant differences in x axis for 2D-2D kV (p=0.000...); mean in the subgroup irradiated without leg supports was 0.14 (SD=0.14) and for the subgroup without them was 0.19 (SD=0.15) and in x axis for CBCT (p=0.03); mean in the subgroup irradiated without leg supports was 0.18 (SD=0.18) and for the subgroup without them was 0.23 (SD=0.22). Significant difference was also revealed for the whole group of absolute shift values for 2D-2D kV (p=0.01). For the subgroup irradiated without leg supports mean was 0.27 (SD=0.34), and for the subgroup treated with them was 0.27 (SD=0.31). Obtained results permit us to conclude that in the case of prostate cancer patients IGRT based on the bone anatomy visualization, the method of choice should be 2D-2D kV, because it allows for more precise and shorter patient position evaluation and, that during IGRT of prostate cancer patients using a simple thermoplastic immobilization system is sufficient; use of more sophisticated systems with additional supports did not improve the patient immobilization.
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Affiliation(s)
- Leszek Miszczyk
- Zaklad Radioterapii, Centrum Onkologii-Instytut im. M. Skłodowskiej-Curie, Oddział w Gliwicach.
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Karimaghaloo Z, Shrawane P, Abolmaesumi P, Fichtinger G, Rohling R. Towards detecting surgical clips in 3D ultrasound for target localization in radiation therapy: a study on tissue phantoms. Annu Int Conf IEEE Eng Med Biol Soc 2008; 2008:5282-5285. [PMID: 19163909 DOI: 10.1109/iembs.2008.4650406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A study is performed to measure the visibility of small surgical clips in 3D ultrasound volumes of a phantom as the first step towards using such clips as fiducial markers in radiation therapy. Visibility is calculated as the contrast to noise ratio of the echo from the clip to the background. The appearance of a resonance tail is also calculated using a moment analysis. Contrast is found to be high and mostly independent of material and size of the clip. All clips are visible, but the length of the tail is found to be dependent on clip orientation to the ultrasound beam. The consistent visibility of the clips suggests they are suitable as fiducial markers in ultrasound and the dependency of the resonance tail on orientation provides an opportunity to distinguish clips from other specular reflectors.
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Affiliation(s)
- Zahra Karimaghaloo
- Department of Electrical and Computer Engineering, Queens University, Kingston, ON K7L3N6, Canada
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Penagaricano JA, Yan Y, Corry P, Moros E, Ratanatharathorn V. Retrospective evaluation of pediatric cranio-spinal axis irradiation plans with the Hi-ART tomotherapy system. Technol Cancer Res Treat 2007; 6:355-60. [PMID: 17668944 DOI: 10.1177/153303460700600413] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Helical tomotherapy (HT) can be used for the delivery of cranio-spinal axis irradiation (CSAI) without the need for beam matching of conventional linac-based external beam irradiation. The aim of this study is to retrospectively evaluate HT plans used for treatment in nine patients treated with CSAI. Helical tomotherapy cranio-spinal axis irradiation (HT-CSAI) plans were created for each patient. Average length along the cranio-spinal axis of the PTV was 65.6 cm with a range between 53 and 74 cm. Treatment planning optimization and plan evaluation parameters were obtained from the HT planning station for each of the nine patients. PTV coverage by the 95% isodose surface ranged between 98.0 to 100.0% for all nine patients. The clinically acceptable dose variation within the PTV or tolerance range was between 0.7 and 2.5% for all nine patients. Doses to the organs at risk were clinically acceptable. An increasing length along the longitudinal axis of the PTV did not consistently increase the beam-on time indicating that using a larger jaw width had a greater impact on treatment time. With a larger jaw width it is possible to substantially reduce the normalized beam-on treatment time without compromising plan quality and sparing of organs at risk. By using a larger jaw width or lower modulation factor or both, normalized beam-on times were decreased by up to 61% as compared to the other evaluated treatment plans. From the nine cases reported in this study the minimum beam-on time was achieved with a jaw width of 5.0 cm, pitch of 0.287 and a modulation factor of 2.0. Large and long cylindrical volumes can be effectively treated with helical tomotherapy with both clinically acceptable dose distribution and beam-on time.
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Affiliation(s)
- José A Penagaricano
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, 4301 W. Markham #771, Little Rock, Arkansas 72205, USA.
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McMahon R, Papiez L, Rangaraj D. Dynamic-MLC leaf control utilizing on-flight intensity calculations: A robust method for real-time IMRT delivery over moving rigid targets. Med Phys 2007; 34:3211-23. [PMID: 17879784 DOI: 10.1118/1.2750964] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
An algorithm is presented that allows for the control of multileaf collimation (MLC) leaves based entirely on real-time calculations of the intensity delivered over the target. The algorithm is capable of efficiently correcting generalized delivery errors without requiring the interruption of delivery (self-correcting trajectories), where a generalized delivery error represents anything that causes a discrepancy between the delivered and intended intensity profiles. The intensity actually delivered over the target is continually compared to its intended value. For each pair of leaves, these comparisons are used to guide the control of the following leaf and keep this discrepancy below a user-specified value. To demonstrate the basic principles of the algorithm, results of corrected delivery are shown for a leading leaf positional error during dynamic-MLC (DMLC) IMRT delivery over a rigid moving target. It is then shown that, with slight modifications, the algorithm can be used to track moving targets in real time. The primary results of this article indicate that the algorithm is capable of accurately delivering DMLC IMRT over a rigid moving target whose motion is (1) completely unknown prior to delivery and (2) not faster than the maximum MLC leaf velocity over extended periods of time. These capabilities are demonstrated for clinically derived intensity profiles and actual tumor motion data, including situations when the target moves in some instances faster than the maximum admissible MLC leaf velocity. The results show that using the algorithm while calculating the delivered intensity every 50 ms will provide a good level of accuracy when delivering IMRT over a rigid moving target translating along the direction of MLC leaf travel. When the maximum velocities of the MLC leaves and target were 4 and 4.2 cm/s, respectively, the resulting error in the two intensity profiles used was 0.1 +/- 3.1% and -0.5 +/- 2.8% relative to the maximum of the intensity profiles. For the same target motion, the error was shown to increase rapidly as (1) the maximum MLC leaf velocity was reduced below 75% of the maximum target velocity and (2) the system response time was increased.
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Affiliation(s)
- Ryan McMahon
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
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Yoshida K, Nose T, Shiomi H, Yoshioka Y, Fujita Y, Kuroda S, Yoshida M, Takahashi T, Kitamura M, Akai H, Oka T, Hosoki T. New ambulatory implant technique of high-dose-rate interstitial brachytherapy for prostate cancer. ACTA ACUST UNITED AC 2007; 24:595-9. [PMID: 17041799 DOI: 10.1007/s11604-007-0058-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2006] [Accepted: 04/01/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE The aim of this study was to improve the performance status of prostate cancer patients during high-dose-rate interstitial brachytherapy (HDR-ISBT). To this end, we have developed a new ambulatory implant technique. MATERIALS AND METHODS Ten prostate cancer patients were treated with HDR-ISBT as monotherapy from October 2003 until March 2004. We utilized a new removable template, a flexible applicator with a nonmetallic bead and button stopper, and an inner catheter connecting the applicator and the transfer tube of the brachytherapy unit. We shortened the connector end of the flexible applicator to enable the patient to sit down and walk freely during the treatment time. RESULTS All 10 patients could walk without any support. No problem in the application was observed. CONCLUSION Our new ambulatory implant technique for HDR-ISBT was able to improve the performance status of prostate cancer patients.
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Affiliation(s)
- Ken Yoshida
- Department of Radiology, Osaka National Hospital, 2-1-14 Hoenzaka, Chuo-ku, Osaka 540-0006, Japan.
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Allgower CE, Schreuder AN, Farr JB, Mascia AE. Experiences with an application of industrial robotics for accurate patient positioning in proton radiotherapy. Int J Med Robot 2007; 3:72-81. [PMID: 17441029 DOI: 10.1002/rcs.128] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Protons beams deliver targeted radiation doses with greater precision than is possible with electrons or megavoltage X-ray photons, but to retain this advantage, patient positioning systems at proton clinics must meet tighter accuracy requirements. For this and other reasons, robots were incorporated into the treatment room systems at MPRI. METHODS The Midwest Proton Radiotherapy Institute (MPRI) is the first radiotherapy facility in the United States to use commercial robots with six degrees of freedom for patient positioning, rather than a traditional bed with four degrees of freedom. RESULTS This paper outlines the ways in which robots are used at MPRI and attempts to distil insights from the experience of treating over 200 radiotherapy patients with a robotic system from February 2004 to late 2006. CONCLUSIONS The system has performed well, and with great reliability, but there is room for future improvement, especially in ease of use and in reducing the time to get patients into position.
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Affiliation(s)
- C E Allgower
- Medical Physics Department, Midwest Proton Radiotherapy Institute, Bloomington, IN 47408, USA.
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Létourneau D, Wong R, Moseley D, Sharpe MB, Ansell S, Gospodarowicz M, Jaffray DA. Online planning and delivery technique for radiotherapy of spinal metastases using cone-beam CT: Image quality and system performance. Int J Radiat Oncol Biol Phys 2007; 67:1229-37. [PMID: 17336223 DOI: 10.1016/j.ijrobp.2006.09.058] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 09/05/2006] [Accepted: 09/28/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To assess the feasibility of an online strategy for palliative radiotherapy (RT) of spinal bone metastasis, which integrates imaging, planning, and treatment delivery in a single step at the treatment unit. The technical challenges of this approach include cone-beam CT (CBCT) image quality for target definition, online planning, and efficient process integration. METHODS AND MATERIALS An integrated imaging, planning, and delivery system was constructed and tested with phantoms. The magnitude of CBCT image artifacts following the use of an antiscatter grid and a nonlinear scatter correction was quantified using phantom data and images of patients receiving conventional palliative RT of the spine. The efficacy of online planning was then assessed using corrected CBCT images. Testing of the complete process was performed on phantoms with assessment of timing and dosimetric accuracy. RESULTS The use of image corrections reduced the cupping artifact from 30% to 4.5% on CBCT images of a body phantom and improved the accuracy of CBCT numbers (water: +/- 20 Hounsfield unit [HU], and lung and bone: to within +/- 130 HU). Bony anatomy was clearly visible and was deemed sufficient for target definition. The mean total time (n = 5) for application of the online approach was 23.1 min. Image-guided dose placement was assessed using radiochromic film measurements with good agreement (within 5% of dose difference and 2 mm of distance to agreement). CONCLUSIONS The technical feasibility of CBCT-guided online planning and delivery for palliative single treatment has been demonstrated. The process was performed in one session equivalent to an initial treatment slot (<30 min) with dosimetric accuracy satisfying accepted RT standards.
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Affiliation(s)
- Daniel Létourneau
- Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada.
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Oyama M, Ueda T, Kitoh S, Goka T, Tanaka T, Ogino T. [Evaluation of irradiation position in respiratory-gated radiotherapy using a phantom system simulating patient respiration]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2007; 62:1666-74. [PMID: 17189933 DOI: 10.6009/jjrt.62.1666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Respiratory-gated (RG) radiotherapy is useful for minimizing the irradiated volume of normal tissues resulting from the shifting of internal structures caused by respiratory movement. The present study was conducted to evaluate the treatment field in RG radiotherapy using a phantom system simulating patient respiration. A phantom system consisting of a 3-cm ball-shaped dummy tumor and film placed in a cork lung phantom was used (THK Co., Ltd.). RG radiotherapy was employed in the expiratory phase. The phantom movement distance was set to 2 cm, and the gating signals from a respiratory-gating system (AZ-733V, Anzai Medical) were varied. The settings used for irradiation were an X-ray energy of 6 MV (PRIMUS, Toshiba Medical Systems), treatment field of 5 cm x 7 cm, and X-ray dose of 100 MU. Images were acquired using an electric portal-imaging device (EPID, OPTIVUE 500), and the X-ray dose distribution was measured by the film method. In images acquired using the EPID, the tumor margins became less clear when the gating signals were increased, and the ITVs were determined to be 3.6 cm, 3.7 cm, 4.2 cm, and 5.1 cm at gating rates of 10%, 25%, 50%, and no gate, respectively. With regard to the X-ray dose distribution measured by the film method, the dose profile in the cephalocaudal direction was shifted toward the expiratory phase, and the degree of shift became greater when the gating signals were increased. In addition, the optimal treatment fields in the cephalocaudal direction were determined to be 5.2 cm, 5.2 cm, 5.6 cm, and 7.0 cm at gating rates of 10%, 25%, 50%, and no gating, respectively. Although RG radiotherapy is useful for improving the accuracy of radiotherapy, the characteristics of the RG radiotherapy technique and the radiotherapy system must be clearly understood when this method is to be employed in clinical practice. Image-guided radiotherapy (IGRT) is now assuming a central role in radiotherapy, and properly identifying internal margins is an important issue for ensuring optimal treatment. The results of this study confirmed that it is necessary to ensure the optimal treatment field in radiotherapy of the trunk and that it is essential to confirm tumor position on the basis of image evaluation.
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Affiliation(s)
- Masaya Oyama
- Department of Radiology, National Canter Center Hospital East
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Abstract
Accurate imaging is a prerequisite for adaptive radiation therapy of mobile tumours. We present an evaluation of the performance of slow computed tomography (CT) for mapping and delineating the excursion boundary of a moving object using a tumour phantom scanned with the helical MVCT scanner of a tomotherapy unit. A spherical test object driven by sinusoidal motion in both the lateral and cranial-caudal directions was used to determine how well MVCT images depict the true envelope of the motion. Such information is useful in interpreting the CT images relative to the static object case when radiotherapy gating is to be used or in determining the internal target volume (ITV) when beam gating is not possible. A computer simulation of the CT imaging process was developed which incorporates the third generation fan beam geometry and helical acquisition technique of the tomotherapy MVCT system. Motion artefacts are mainly characterized by the parameter alpha=Tgantry/Trespiration which is interpreted as the period of the gantry rotation (Tgantry) in units of the respiratory period (Trespiration). Experimental tests were performed using a fixed gantry period of 10 s per full rotation and respiratory period ranging from 4.0 (alpha=2.5) to 1.0 (alpha=10) s. These cases represent typical clinical imaging conditions on the tomotherapy unit, as well as an extreme test case where the gantry period is intentionally set to be much greater than the respiratory period (termed an 'ultra-slow' scan). The accuracy of target (ITV) delineation is evaluated by comparing volumes generated using iso-density contours on the MVCT images to the true motion envelope, known a priori in this phantom study. As expected, motion artefacts are present in clinical MVCT images and they are not averaged over the slow gantry period of rotation. Furthermore, artefacts are not significantly affected by scanning with different helical pitch values. Greater distortions from the true density distribution are observed for lateral motion compared to cranial-caudal motion. Volumes generated by iso-density contours yield better agreement with the motion envelope for scans performed under ultra-slow conditions (alpha=10) compared to typical clinical imaging conditions (alpha=2.5). If the MVCT gantry cannot be rotated very quickly due to engineering constraints in order to achieve ultra-fast CT, we suggest an opposite approach as an interim measure for mapping the ITV. Adjusting MVCT scan conditions to a very slow acquisition (alpha=10) may be a good compromise for determining the ITV for non-gated adaptive tomotherapy of moving lung tumours.
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Affiliation(s)
- Christopher Smeenk
- Radiation Oncology Program, London Regional Cancer Program, London, Ontario, Canada
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Suzuki O, Shiomi H, Nakamura S, Nakayama F, Yoshioka Y, Inoue T. Novel correction methods as alternatives for the six-dimensional correction in CyberKnife treatment. ACTA ACUST UNITED AC 2007; 25:31-7. [PMID: 17225051 DOI: 10.1007/s11604-006-0092-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Accepted: 09/03/2006] [Indexed: 11/29/2022]
Abstract
PURPOSE During CyberKnife treatment, the 6D correction method is used to correct patient positional errors, including rotational ones. We developed novel correction methods for translating rotational errors into 3D, with the aim of making their correction safer than with 6D correction and as accurate as possible. MATERIALS AND METHODS These novel correction methods were named the gravity correction and the beam correction method. With the gravity correction method, the beam coordinates after rotation are corrected to match the tumor gravity point with 3D translational components translated by the affine transformation matrix. For beam correction, the beam coordinates are corrected to match the translated tumor target coordinates for each treatment beam. The effectiveness and impact of these methods were demonstrated by means of dose volume histogram (DVH) shift evaluation. For analysis of the treatment data of 10 patients, the treatment beam was rotated in three patterns of rotational degree and corrected with the two methods. The amount of tumor gravity point shift in the rotation was also calculated, and the deterioration of the tumor DVH was studied. RESULTS In the case of +/-1 degrees , +/-3 degrees , and +/-1 degrees rotation for the X, Y, Z axes, the tumor gravity point of all 10 patients moved around 2.4 mm on average. Tumor DVH was deteriorated worse as the distance between the tumor gravity point and the rotational origin became more distant. With the planned D90, which represents the dose above which 90% of the tumor volume is irradiated set at 100%, the postrotational average D90 dose deteriorated to 96.12% after (+/-1 degrees , +/-3 degrees , and +/-1 degrees ) rotation. The dose was improved to 99.9% (SD +/- 0.41) after the gravity correction, or to 99.87% (SD +/- 0.55) after the beam correction. CONCLUSION The correction methods developed by us can correct tumor DVH findings to the same degree as with 6D correction and are safer because the movement required for correcting the linac is not rotational but translational only.
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Affiliation(s)
- Osamu Suzuki
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita 565-0871, Japan.
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Abstract
Image-guided radiotherapy using a three-dimensional (3D) camera as the on-board surface imaging system requires precise and accurate registration of the 3D surface images in the treatment machine coordinate system. Two simple calibration methods, an analytical solution as three-point matching and a least-squares estimation method as multipoint registration, were introduced to correlate the stereo-vision surface imaging frame with the machine coordinate system. Both types of calibrations utilized 3D surface images of a calibration template placed on the top of the treatment couch. Image transformational parameters were derived from corresponding 3D marked points on the surface images to their given coordinates in the treatment room coordinate system. Our experimental results demonstrated that both methods had provided the desired calibration accuracy of 0.5 mm. The multipoint registration method is more robust particularly for noisy 3D surface images. Both calibration methods have been used as our weekly QA tools for a 3D image-guided radiotherapy system.
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Affiliation(s)
- Dezhi Liu
- Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan 48202, USA.
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Mazeron JJ, Lang P, Simon JM, Toubiana T, Feuvret L, Boisserie G. [New devices in radiation oncology]. Bull Cancer 2007; 94:109-13. [PMID: 17237011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Accepted: 11/28/2006] [Indexed: 05/13/2023]
Abstract
The development of sophisticated conformal radiation techniques, such as intensity-modulated radiation therapy, image-guided radiation therapy, adaptative radiation therapy, and radiosurgery, implies precise and accurate targeting. To achieve this goal, a lot of new devices and techniques have been designed and are now available in radiation therapy departments : modern 3D-imaging systems, sophisticated treatment planning systems, breathing-adapted radiotherapy equipments (for gating and tracking techniques), in-room 3D-imaging systems, tomotherapy, etc. Purpose of this review is to briefly present the new equipments which are now used in radiation therapy departments in conformal therapy.
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Affiliation(s)
- Jean-Jacques Mazeron
- Groupe hospitalier Pitié-Salpêtrière, Service d'oncologie radiothérapique, 43-87 boulevard de l'Hôpital, 75661 Paris Cedex 13.
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Pasquino M, Borca VC, Catuzzo P, Ozzello F, Tofani S. Transmission, Penumbra and Leaf Positional Accuracy in Commissioning and Quality Assurance Program of a Multileaf Collimator for Step-and-Shoot IMRT Treatments. Tumori 2006; 92:511-6. [PMID: 17260492 DOI: 10.1177/030089160609200608] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aims and background The performance characteristics of a commercial multileaf collimator (MLC) for intensity modulated radiation therapy (IMRT) and a comprehensive quality assurance program (QA) to be performed during the commissioning of the MLC were investigated. Materials and methods The midleaf transmission and interleaf leakage, the in-plane penumbra and its in-plane/cross-plane variation, the cross-plane penumbra and its in-plane/cross-plane variation, and the leaf positional accuracy of a high-energy photon (6 MV) Sli Precise Elekta linear accelerator were measured. Kodak EDR2 Ready Pack film was used for MLC transmission measurement; for the other characterization measurements we used Kodak X-Omat XV2 Ready Pack film placed at 5 cm depth in a solid RW3 phantom. Each film was digitized with a laser scanning photodensitometer VXR-12 Plus using the Omni Pro-Accept 6.0A film dosimetry system and converted to dose by means of H&D curves. The dose calibration measurements were performed with a Farmer ionization chamber according to the guidelines of the IAEA Technical Report No. 277. Results The average midleaf transmission and interleaf leakage were 1.8% ± 0.1% and 2.1% ± 0.2%, respectively. The average value of the cross-plane penumbra was 5.4 mm ± 0.3 mm with maximum variation less than 0.4 mm and 1.0 mm in the in-plane and cross-plane direction, respectively. The average value of the in-plane penumbra was 3.2 mm ± 0.2 mm and 3.5 mm ± 0.2 mm for the step side and groove side of the leaves, respectively. A dose profile perpendicular to the direction of the leaf travel passing through the central axis shows a tongue-and-groove effect of about 33%. The positional accuracy of the leaves was investigated according to AAPM Report No. 72 TG50; the deviation of the net optical density along all the match lines was less than ± 20%. Moreover, the results obtained with a step field technique showed a positional accuracy of less than 1 mm. Conclusions The results suggest the necessity of extensive knowledge of the MLC dosimetric characteristics for IMRT applications in order to allow physicists to study their influence on treatment delivery and to perform a comprehensive routine QA program of the investigated parameters.
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Affiliation(s)
- Massimo Pasquino
- SC Fisica Sanitaria,, Azienda Ospedaliera ASL 9, Ivrea, Turin, Italy.
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Donovan EM, Brabants P, Evans PM, Symonds-Tayler JRN, Wilks R. Accuracy and precision of an external-marker tracking-system for radiotherapy treatments. Br J Radiol 2006; 79:808-17. [PMID: 16980676 DOI: 10.1259/bjr/24917728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The purpose of this work was to determine the accuracy and precision of a real-time motion-tracking system (Osiris+) for the monitoring of external markers used on patients receiving radiotherapy treatments. Random and systematic errors in the system were evaluated for linear (1D), circular (2D) and elliptical (3D) continuous motions, and for a set of static positions offset from an origin. A Wellhofer beam data measurement system and a computer controlled platform (which could be programmed to give motion in 3D) were used to move a hemi-spherical test object. The test object had four markers of the type used on patients. Three markers were aligned in the central plane and a fourth was positioned out of plane. Errors were expressed as deviations from the planned positions at the sampled time points. The marked points on the test object were tracked for the linear motion case with a variation from the true position of less than +/-1 mm, except for two extreme situations. The variation was within +/-2 mm when the lights were dimmed and when the amplitude of the movement was +/-5.0 cm. The 2D circular motion was tracked with a standard deviation of 1 mm or less over four cycles. The sampling rates of the system were found to be 0.3-0.4 s when it was monitoring actively and 1.5-1.6 s otherwise. The recorded Osiris+ measurements of known static positions were within +/-1 mm of the value from the computer controlled platform moving the test object. The elliptical motions in 3D were tracked to +/-1 mm in two directions (Y,Z), and generally to within +/-2 mm for the third direction (X); however, specific marked points could display an error of up to 5 mm at certain positions in X. The overall displacement error for the 3D motion was +/-1 mm with a standard deviation of 2.5 mm. The system performance is satisfactory for use in tracking external marker motion during radiotherapy treatments.
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Affiliation(s)
- E M Donovan
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT, UK
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Gibbs IC. Frameless image-guided intracranial and extracranial radiosurgery using the Cyberknife™ robotic system. Cancer Radiother 2006; 10:283-7. [PMID: 16859948 DOI: 10.1016/j.canrad.2006.05.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2006] [Accepted: 05/31/2006] [Indexed: 11/21/2022]
Abstract
The Cyberknife is an image-guided robotic radiosurgery system. The image guidance system includes a kilovoltage X-ray imaging source and amorphous silica detectors. The radiation delivery device is a mobile X-band linear accelerator mounted onto a robotic arm. Through a highly complex interplay between the image guidance system, an automated couch, and the high-speed linear accelerator, near real-time tracking of the target is achieved. The Cyberknife gained Federal Drug Administration clearance in the United States in 2001 for treatment of tumors "anywhere in the body where radiation treatment is indicated." Because the Cyberknife system does not rely on rigid fixation of a stereotactic frame, tumors outside of the intracranial compartment, even those tumors that move with respiration can be treated with a similar degree of ease as intracranial targets. A description of the Cyberknife technology and a review of some of the current intracranial and extracranial applications are detailed herein.
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Affiliation(s)
- I C Gibbs
- Stanford University, 875 Blake Wilbur Drive, Room G222A, Stanford, CA 94305-5847, USA.
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