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https://www.readbyqxmd.com/read/27523422/-image-guided-radiotherapy
#1
R de Crevoisier, B Chauvet, I Barillot, C Lafond, M Mahé, G Delpon
The IGRT is described in its various equipment and implementation. IGRT can be based either on ionizing radiation generating 2D imaging (MV or kV) or 3D imaging (CBCT or MV-CT) or on non-ionizing radiation (ultrasound, optical imaging, MRI or radiofrequency). Adaptive radiation therapy is then presented in its principles of implementation. The function of the technicians for IGRT is then presented and the possible dose delivered by the on-board imaging is discussed. The quality control of IGRT devices is finally described...
September 2016: Cancer Radiothérapie: Journal de la Société Française de Radiothérapie Oncologique
https://www.readbyqxmd.com/read/27455505/characterization-and-evaluation-of-2-5-mv-electronic-portal-imaging-for-accurate-localization-of-intra-and-extracranial-stereotactic-radiosurgery
#2
Kwang Hyun Song, Karen Chin Snyder, Jinkoo Kim, Haisen Li, Wen Ning, Robert Rusnac, Paul Jackson, James Gordon, Salim M Siddiqui, Indrin J Chetty
2.5 MV electronic portal imaging, available on Varian TrueBeam machines, was characterized using various phantoms in this study. Its low-contrast detectability, spatial resolution, and contrast-to-noise ratio (CNR) were compared with those of conventional 6 MV and kV planar imaging. Scatter effect in large patient body was simulated by adding solid water slabs along the beam path. The 2.5 MV imaging mode was also evaluated using clinically acquired images from 24 patients for the sites of brain, head and neck, lung, and abdomen...
2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/27280244/quantitative-3d-determination-of-radiosensitization-by-bismuth-based-nanoparticles
#3
Mamdooh Alqathami, Anton Blencowe, Moshi Geso, Geoffrey Ibbott
The nanoparticle-induced dose enhancement effect has been shown to improve the therapeutic efficacy of ionizing radiation in external beam radiotherapy. Whereas previous studies have focused on gold nanoparticles (AuNPs), no quantitative studies have been conducted to investigate the potential superiority of other high atomic number (Z) nanomaterials such as bismuth-based nanoparticles. The aims of this study were to experimentally validate and quantify the dose enhancement properties of commercially available bismuth-based nanoparticles (bismuth oxide (Bi2O3-NPs) and bismuth sulfide (Bi2S3-NPs)), and investigate their potential superiority over AuNPs in terms of radiation dose enhancement...
March 2016: Journal of Biomedical Nanotechnology
https://www.readbyqxmd.com/read/27147314/optimizing-fiducial-visibility-on-periodically-acquired-megavoltage-and-kilovoltage-image-pairs-during-prostate-volumetric-modulated-arc-therapy
#4
Pengpeng Zhang, Laura Happersett, Bosky Ravindranath, Michael Zelefsky, Gig Mageras, Margie Hunt
PURPOSE: Robust detection of implanted fiducials is essential for monitoring intrafractional motion during hypofractionated treatment. The authors developed a plan optimization strategy to ensure clear visibility of implanted fiducials and facilitate 3D localization during volumetric modulated arc therapy (VMAT). METHODS: Periodic kilovoltage (kV) images were acquired at 20° gantry intervals and paired with simultaneously acquired 4.4° short arc megavoltage digital tomosynthesis (MV-DTS) to localize three fiducials during VMAT delivery for hypofractionated prostate cancer treatment...
May 2016: Medical Physics
https://www.readbyqxmd.com/read/27130830/practical-assessment-of-bronchoscopically-inserted-fiducial-markers-for-image-guidance-in-stereotactic-lung-radiotherapy
#5
Price Jackson, Daniel P Steinfort, Tomas Kron, Shankar Siva
INTRODUCTION: Stereotactic radiotherapy is a high-dose precision technique necessitating accurate target visualization through either cone beam computed tomography (CBCT) or planar imaging with implanted fiducial markers. We have investigated the properties for image guidance using fiducial markers implanted through minimally invasive bronchoscopy. METHODS: Two fiducial marker types were implanted endobronchially in 10 patients undergoing radical radiation treatment for non-small cell lung cancer (eight using Visicoil linear fiducial markers [IBA Dosimetry GmbH, Schwarzenbruck Germany] and two using superDimension and superLock two-band markers [Covidien Inc...
August 2016: Journal of Thoracic Oncology
https://www.readbyqxmd.com/read/27074487/assessment-of-image-quality-and-dose-calculation-accuracy-on-kv-cbct-mv-cbct-and-mv-ct-images-for-urgent-palliative-radiotherapy-treatments
#6
Mareike Held, Florian Cremers, Penny K Sneed, Steve Braunstein, Shannon E Fogh, Jean Nakamura, Igor Barani, Angelica Perez-Andujar, Jean Pouliot, Olivier Morin
A clinical workflow was developed for urgent palliative radiotherapy treatments that integrates patient simulation, planning, quality assurance, and treatment in one 30-minute session. This has been successfully tested and implemented clinically on a linac with MV CBCT capabilities. To make this approach available to all clin-ics equipped with common imaging systems, dose calculation accuracy based on treatment sites was assessed for other imaging units. We evaluated the feasibility of palliative treatment planning using on-board imaging with respect to image quality and technical challenges...
2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/26864049/towards-clinical-implementation-of-ultrafast-combined-kv-mv-cbct-for-igrt-of-lung-cancer-evaluation-of-registration-accuracy-based-on-phantom-study
#7
Anna Arns, Manuel Blessing, Jens Fleckenstein, Dzmitry Stsepankou, Judit Boda-Heggemann, Anna Simeonova-Chergou, Jürgen Hesser, Frank Lohr, Frederik Wenz, Hansjörg Wertz
PURPOSE: Combined kV-MV cone-beam CT (CBCT) is a promising approach to accelerate imaging for patients with lung tumors treated with deep inspiration breath-hold. During a single breath-hold (15 s), a 3D kV-MV CBCT can be acquired, thus minimizing motion artifacts and increasing patient comfort. Prior to clinical implementation, positioning accuracy was evaluated and compared to clinically established imaging techniques. METHODS AND MATERIALS: An inhomogeneous thorax phantom with four tumor-mimicking inlays was imaged in 10 predefined positions and registered to a planning CT...
May 2016: Strahlentherapie und Onkologie: Organ der Deutschen Röntgengesellschaft ... [et Al]
https://www.readbyqxmd.com/read/26852244/individualized-radiotherapy-by-combining-high-end-irradiation-and-magnetic-resonance-imaging
#8
REVIEW
Stephanie E Combs, Fridtjof Nüsslin, Jan J Wilkens
Image-guided radiotherapy (IGRT) has been integrated into daily clinical routine and can today be considered the standard especially with high-dose radiotherapy. Currently imaging is based on MV- or kV-CT, which has clear limitations especially in soft-tissue contrast. Thus, combination of magnetic resonance (MR) imaging and high-end radiotherapy opens a new horizon. The intricate technical properties of MR imagers pose a challenge to technology when combined with radiation technology. Several solutions that are almost ready for routine clinical application have been developed...
April 2016: Strahlentherapie und Onkologie: Organ der Deutschen Röntgengesellschaft ... [et Al]
https://www.readbyqxmd.com/read/26717197/geometric-validation-of-mv-topograms-for-patient-localization-on-tomotherapy
#9
Janid P Blanco Kiely, Benjamin M White, Daniel A Low, Sharon X Qi
Our goal was to geometrically validate the use of mega-voltage orthogonal scout images (MV topograms) as a fast and low-dose alternative to mega-voltage computed tomography (MVCT) for daily patient localization on the TomoTherapy system. To achieve this, anthropomorphic head and pelvis phantoms were imaged on a 16-slice kilo-voltage computed tomography (kVCT) scanner to synthesize kilo-voltage digitally reconstructed topograms (kV-DRT) in the Tomotherapy detector geometry. MV topograms were generated for couch speeds of 1-4 cm s(-1) in 1 cm s(-1) increments with static gantry angles in the anterior-posterior and left-lateral directions...
January 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/26520738/technical-report-tg-142-compliant-and-comprehensive-quality-assurance-tests-for-respiratory-gating
#10
Kyle Woods, Yi Rong
PURPOSE: To develop and establish a comprehensive gating commissioning and quality assurance procedure in compliance with TG-142. METHODS: Eight Varian TrueBeam Linacs were used for this study. Gating commissioning included an end-to-end test and baseline establishment. The end-to-end test was performed using a CIRS dynamic thoracic phantom with a moving cylinder inside the lung, which was used for carrying both optically simulated luminescence detectors (OSLDs) and Gafchromic EBT2 films while the target is moving, for a point dose check and 2D profile check...
November 2015: Medical Physics
https://www.readbyqxmd.com/read/26461006/accumulated-delivered-dose-response-of-stereotactic-body-radiation-therapy-for-liver-metastases
#11
Anand Swaminath, Christine Massey, James D Brierley, Rob Dinniwell, Rebecca Wong, John J Kim, Michael Velec, Kristy K Brock, Laura A Dawson
PURPOSE: To determine whether the accumulated dose using image guided radiation therapy is a stronger predictor of clinical outcomes than the planned dose in stereotactic body radiation therapy (SBRT) for liver metastases. METHODS AND MATERIALS: From 2003 to 2009, 81 patients with 142 metastases were treated in institutional review board-approved SBRT studies (5-10 fractions). Patients were treated during free breathing (with or without abdominal compression) or with controlled exhale breath-holding...
November 1, 2015: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/26429263/gold-nanoparticle-induced-vasculature-damage-in-radiotherapy-comparing-protons-megavoltage-photons-and-kilovoltage-photons
#12
COMPARATIVE STUDY
Yuting Lin, Harald Paganetti, Stephen J McMahon, Jan Schuemann
PURPOSE: The purpose of this work is to investigate the radiosensitizing effect of gold nanoparticle (GNP) induced vasculature damage for proton, megavoltage (MV) photon, and kilovoltage (kV) photon irradiation. METHODS: Monte Carlo simulations were carried out using tool for particle simulation (TOPAS) to obtain the spatial dose distribution in close proximity up to 20 μm from the GNPs. The spatial dose distribution from GNPs was used as an input to calculate the dose deposited to the blood vessels...
October 2015: Medical Physics
https://www.readbyqxmd.com/read/26377196/concept-for-quantifying-the-dose-from-image-guided-radiotherapy
#13
Uwe Schneider, Roger Hälg, Jürgen Besserer
BACKGROUND: Radiographic image guidance is routinely used for patient positioning in radiotherapy. All radiographic guidance techniques can give a significant radiation dose to the patient. The dose from diagnostic imaging is usually managed by using effective dose minimization. In contrast, image-guided radiotherapy adds the imaging dose to an already high level of therapeutic radiation which cannot be easily managed using effective dose. The purpose of this work is the development of a concept of IGRT dose quantification which allows a comparison of imaging dose with commonly accepted variations of therapeutic dose...
2015: Radiation Oncology
https://www.readbyqxmd.com/read/26233193/generation-of-hybrid-sinograms-for-the-recovery-of-kv-ct-images-with-metal-artifacts-for-helical-tomotherapy
#14
Hosang Jeon, Dahl Park, Hanbean Youn, Jiho Nam, Jayoung Lee, Wontaek Kim, Yongkan Ki, Yong Ho Kim, Ju Hye Lee, Dongwon Kim, Ho Kyung Kim
PURPOSE: The overall goal of this study is to restore kilovoltage computed tomography (kV-CT) images which are disfigured by patients' metal prostheses. By generating a hybrid sinogram that is a combination of kV and megavoltage (MV) projection data, the authors suggest a novel metal artifact-reduction (MAR) method that retains the image quality to match that of kV-CT and simultaneously restores the information of metal prostheses lost due to photon starvation. METHODS: CT projection data contain information about attenuation coefficients and the total length of the attenuation...
August 2015: Medical Physics
https://www.readbyqxmd.com/read/26204919/accumulated-dose-to-the-rectum-measured-using-dose-volume-histograms-and-dose-surface-maps-is-different-from-planned-dose-in-all-patients-treated-with-radiotherapy-for-prostate-cancer
#15
Jessica E Scaife, Simon J Thomas, Karl Harrison, Marina Romanchikova, Michael P F Sutcliffe, Julia R Forman, Amy M Bates, Raj Jena, M Andrew Parker, Neil G Burnet
OBJECTIVE: We sought to calculate accumulated dose (DA) to the rectum in patients treated with radiotherapy for prostate cancer. We were particularly interested in whether dose-surface maps (DSMs) provide additional information to dose-volume histograms (DVHs). METHODS: Manual rectal contours were obtained for kilovoltage and daily megavoltage CT scans for 10 participants from the VoxTox study (380 scans). Daily delivered dose recalculation was performed using a ray-tracing algorithm...
October 2015: British Journal of Radiology
https://www.readbyqxmd.com/read/26129524/th-c-brd-01-optimization-of-ct-simulation-imaging-in-radiation-therapy-background-and-motivations
#16
H Al-Hallaq
UNLABELLED: IGRT has significantly improved the accuracy of radiation treatment by utilizing CT scans for contouring target and organ during treatment planning and x-ray imaging devices integrated to treatment units for patient positioning during radiation delivery. A significant progress has been made recently to improve CT image quality in treatment planning and to reduce daily imaging guidance dose. This course is designed to provide educational guidance on these two important imaging issues...
June 2015: Medical Physics
https://www.readbyqxmd.com/read/26129523/th-c-brd-02-optimization-of-ct-simulation-imaging-in-radiation-therapy-strategies-and-tools
#17
I Reiser
UNLABELLED: IGRT has significantly improved the accuracy of radiation treatment by utilizing CT scans for contouring target and organ during treatment planning and x-ray imaging devices integrated to treatment units for patient positioning during radiation delivery. A significant progress has been made recently to improve CT image quality in treatment planning and to reduce daily imaging guidance dose. This course is designed to provide educational guidance on these two important imaging issues...
June 2015: Medical Physics
https://www.readbyqxmd.com/read/26129520/th-c-brd-00-optimization-of-ct-planning-imaging-and-techniques-to-reduce-radiation-dose-resulting-from-daily-imaging-guidance-procedures
#18
Zhengfeng Lu
UNLABELLED: IGRT has significantly improved the accuracy of radiation treatment by utilizing CT scans for contouring target and organ during treatment planning and x-ray imaging devices integrated to treatment units for patient positioning during radiation delivery. A significant progress has been made recently to improve CT image quality in treatment planning and to reduce daily imaging guidance dose. This course is designed to provide educational guidance on these two important imaging issues...
June 2015: Medical Physics
https://www.readbyqxmd.com/read/26129519/th-c-brd-03-techniques-to-reduce-radiation-dose-resulting-from-daily-imaging-guidance-procedures
#19
G Ding
UNLABELLED: IGRT has significantly improved the accuracy of radiation treatment by utilizing CT scans for contouring target and organ during treatment planning and x-ray imaging devices integrated to treatment units for patient positioning during radiation delivery. A significant progress has been made recently to improve CT image quality in treatment planning and to reduce daily imaging guidance dose. This course is designed to provide educational guidance on these two important imaging issues...
June 2015: Medical Physics
https://www.readbyqxmd.com/read/26129468/th-ab-303-11-automatic-prostate-intrafraction-motion-management
#20
W Liu, R Nath
PURPOSE: Intrafraction motion management is important for prostate radiotherapy when tight margin is used especially for hypo-fractional treatment. We evaluate the benefits of imaging strategies in the situation of manual and automatic motion correction. METHODS: Prostate position information was acquired continuously using electromagnetic transponder at two institutions from 17 and 30 patients (536 and 883 trajectories), respectively. We simulated 7 -field IMRT delivery with periodic imaging at various frequencies and with continuous adaptive imaging...
June 2015: Medical Physics
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