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Helical tomotherapy

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https://www.readbyqxmd.com/read/28214420/prevention-of-radiotherapy-induced-neurocognitive-dysfunction-in-survivors-of-paediatric-brain-tumours-the-potential-role-of-modern-imaging-and-radiotherapy-techniques
#1
REVIEW
Thankamma Ajithkumar, Stephen Price, Gail Horan, Amos Burke, Sarah Jefferies
Neurocognitive dysfunction is the leading cause of reduced quality of life in long-term survivors of paediatric brain tumours. Radiotherapy is one of the main contributors to neurocognitive sequelae. Current approaches for prevention and reduction of neurocognitive dysfunction include avoidance of radiotherapy in young children and reduction of the radiotherapy dose and volume of brain irradiated. Substantial advances have been made in brain imaging, especially with functional imaging and fibre tracking with the use of diffusion tensor imaging...
February 2017: Lancet Oncology
https://www.readbyqxmd.com/read/28199977/pre-radiotherapy-neutrophil-to-lymphocyte-ratio-as-an-independent-prognostic-factor-in-patients-with-locally-advanced-hepatocellular-carcinoma-treated-with-radiotherapy
#2
Seok Hyun Son, Eun Young Park, Hee Hyun Park, Chul Seung Kay, Hong Seok Jang
We aimed to investigate the pre-radiotherapy neutrophil-to-lymphocyte ratio (prNLR) as a prognostic factor in patients with locally advanced hepatocellular carcinoma (HCC) treated with radiotherapy (RT), and to determine the optimal cut-off value for prNLR. We retrospectively evaluated 56 patients with locally advanced HCC treated with RT (helical tomotherapy) between March 2006 and February 2012. The optimal cut-off value was determined by using a maximally selected log-rank test. Prognostic factors that influence the local progression-free survival (PFS) and overall survival (OS) were evaluated...
February 9, 2017: Oncotarget
https://www.readbyqxmd.com/read/28159930/compared-planning-dosimetry-of-tomo-vmat-and-imrt-in-rectal-cancer-with-different-simulated-positions
#3
Jang-Chun Lin, Jo-Ting Tsai, Li-Jhen Chen, Ming-Hsien Li, Wei-Hsiu Liu
OBJECTIVES: To compare treatment plans for helical tomotherapy (TOMO), volumetric modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for locally advanced rectal cancer (LARC). MATERIALS AND METHODS: This retrospective study from December 2010 to June 2013 included 20 patients with LARC who received neoadjuvant concurrent chemoradiotherapy (CCRT) with radiation doses of greater than 50.4 Gy. Dosimetric quality was evaluated based on doses to organs at risk (OARs), including small bowel, urinary bladder and bilateral femoral head, over the same coverage of the clinical target volume (CTV)...
January 31, 2017: Oncotarget
https://www.readbyqxmd.com/read/28155608/helical-tomotherapy-versus-conventional-technique-for-post-mastectomy-left-sided-breast-cancer-dosimetric-study
#4
M O Alshabanah, Mohamed Hegazy, Belal Moftah, Mohammad Shabanah
METHODS AND MATERIALS: Treatment plans were generated for 5 post mastectomy left sided breast cancer patients treated at king Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia, comparing three-dimensional technique with the HT planning. The prescribed dose was 50 Gy in 25 fractions; the planning target volume (chest wall and nodal volumes) was contoured according to RTOG atlas and the heart, lungs, spinal cord and contralateral breast were contoured as Organs at Risks (OARs)...
February 1, 2017: Reviews on Recent Clinical Trials
https://www.readbyqxmd.com/read/28143487/helical-tomotherapy-of-spinal-chordomas-french-multicentric-retrospective-study-of-a-cohort-of-30-cases
#5
Maxime Bobin, Christina Zacharatou, Paul Sargos, Véronique Brouste, Albert Lisbona, Marc-André Mahé, Georges Noël, Amandine Halley, Loïc Feuvret, Louis Gras, Stéphanie Hoppe, Bénédicte Henriques de Figueiredo, Guy Kantor
PURPOSE: To evaluate the efficacy and toxicity of helical tomotherapy (HT) in the management of spine chordomas when proton therapy is unavailable or non-feasible. METHODS AND MATERIALS: Between 2007 and 2013, 30 patients with biopsy-proven chordomas were treated by HT in five French institutions. Information regarding local control (LC), overall survival (OS), progression-free survival (PFS) and metastasis-free survival (MFS) was collected. Clinical efficacy, toxicity and treatment quality were evaluated...
January 31, 2017: Radiation Oncology
https://www.readbyqxmd.com/read/28129971/dosimetric-aspects-of-breast-radiotherapy-with-three-dimensional-and-intensity-modulated-radiotherapy-helical-tomotherapy-planning-modules
#6
Poonam Yadav, Yue Yan, Tasha Ignatowski, Anna Olson
In this work, we investigated the dosimetric differences between the intensity-modulated radiotherapy (IMRT) plans and the three-dimensional (3D) helical plans based on the TomoTherapy system. A total of 15 patients with supine setup were randomly selected from the data base. For patients with lumpectomy planning target volume (PTV), regional lymph nodes were also included as part of the target. For dose sparing, the significant differences between the helical IMRT and helical 3D were only found in the heart and contralateral breast...
January 24, 2017: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
https://www.readbyqxmd.com/read/28129767/helical-tomotherapy-for-locally-advanced-or-recurrent-breast-cancer
#7
M N Duma, C Heinrich, C Schönknecht, B Chizzali, M Mayinger, M Devecka, S Kampfer, S E Combs
PURPOSE: We report our experience of using helical tomotherapy (HT) to treat large and irregular shaped loco-regional advanced breast cancer target volumes embracing various organs at risk. PATIENTS AND METHODS: We retrospectively analyzed 26 patients treated for very large, irregular shaped breast cancers. Patients were treated either with the intent to achieve local control in a primary setting (n = 14) or in a reirradiation setting (n = 12). The recurrence group was heavily pretreated with systemic therapy...
January 28, 2017: Radiation Oncology
https://www.readbyqxmd.com/read/28126476/optimization-of-brain-metastases-radiotherapy-with-tomohda
#8
Slav Yartsev, Glenn Bauman
An upgrade of the helical tomotherapy technology by introducing variable fan-field width (dynamic jaws) reduced the penumbra in superior-inferior direction for the target. Possible implementation of this upgrade even for the cases of the targets with different dose prescriptions is proposed. An example of brain metastasis in proximity to the optical apparatus in need of the whole brain irradiation of 30 Gy and higher dose to the lesion is considered.
January 23, 2017: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
https://www.readbyqxmd.com/read/28126475/clinical-benefits-of-new-immobilization-system-for-hypofractionated-radiotherapy-of-intrahepatic-hepatocellular-carcinoma-by-helical-tomotherapy
#9
Yong Hu, Yong-Kang Zhou, Yi-Xing Chen, Shi-Ming Shi, Zhao-Chong Zeng
OBJECTIVE: A comprehensive clinical evaluation was conducted, assessing the Body Pro-Lok immobilization and positioning system to facilitate hypofractionated radiotherapy of intrahepatic hepatocellular carcinoma (HCC), using helical tomotherapy to improve treatment precision. METHODS: Clinical applications of the Body Pro-Lok system were investigated (as above) in terms of interfractional and intrafractional setup errors and compressive abdominal breath control...
January 23, 2017: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
https://www.readbyqxmd.com/read/28110824/clinical-significance-of-treatment-delivery-errors-for-helical-tomotherapy-nasopharyngeal-plans-a-dosimetric-simulation-study
#10
Shrikant Deshpande, Mark Geurts, Philip Vial, Peter Metcalfe, Mark Lee, Lois Holloway
PURPOSE: Develop a framework to characterize helical TomoTherapy (HT) machine delivery errors and their clinical significance. METHOD AND MATERIALS: Ten nasopharynx HT plans were edited to introduce errors in Jaw width (JW), couch speed (CS), gantry period (GP), gantry start position (GSP), multi leaf collimator leaf open times (MLC LOT). In case of MLC LOT only, both systematic and random delivery errors were investigated. Each error type was simulated independently for a range of magnitudes...
January 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28096196/craniospinal-irradiation-using-helical-tomotherapy-for-central-nervous-system-tumors
#11
Sanziana R I Schiopu, Gregor Habl, Matthias Häfner, Sonja Katayama, Klaus Herfarth, Juergen Debus, Florian Sterzing
The aim of this study was to describe early and late toxicity, survival and local control in 45 patients with primary brain tumors treated with helical tomotherapy craniospinal irradiation (HT-CSI). From 2006 to 2014, 45 patients with central nervous system malignancies were treated with HT-CSI. The most common tumors were medulloblastoma in 20 patients, ependymoma in 10 patients, intracranial germinoma (ICG) in 7 patients, and primitive neuroectodermal tumor in 4 patients. Hematological toxicity during treatment included leukopenia Grades 1-4 (6...
January 17, 2017: Journal of Radiation Research
https://www.readbyqxmd.com/read/28089479/estimation-of-radiation-induced-secondary-cancer-risks-for-early-stage-non-small-cell-lung-cancer-patients-after-stereotactic-body-radiation-therapy
#12
Chunhui Han, Timothy E Schultheiss, Jeffrey Y C Wong
PURPOSE: In this study, we evaluated radiation-induced secondary lung cancer risks for the lung and the breast from stereotactic body radiation therapy treatment of early-stage non-small cell lung cancer with different radiation therapy treatment modalities. METHODS AND MATERIALS: Ten patients (5 men and 5 women) with early-stage non-small cell lung cancer who received definitive stereotactic body radiation therapy treatments were retrospectively selected. For each patient, two 3-dimensional conformal radiation therapy (3D-CRT) plans using 6- and 10-MV photons, respectively; a helical tomotherapy (HT) plan; and 2 volumetric modulated arc therapy (VMAT) plans using 1 and 2 arcs, respectively, were generated...
October 19, 2016: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28048605/su-f-t-331-the-effect-of-optimization-grid-size-on-helical-tomotherapy-for-nasopharyngeal-carcinama
#13
J Gu, Y Yin, J Zhu
PURPOSE: To investigate the effect of plan optimization grid size on helical tomotherapy for nasopharyngeal carcinoma (NPC) METHODS: Ten patients of NPC were enrolled. For each patient, three plans with different dose optimization grid size (fine, normal, coarse) were created by Helical Tomotherapy Planning Station (version: 5.0, GPU Acceleration and VoLo).The time consumed by 500 optimization iterations, the monitor units and the dose volume histogram factors were compared. Paired-Wilcoxon test was used in statistical analysis...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048587/tu-h-brc-07-therapeutic-benefit-in-spatially-fractionated-radiotherapy-grid-using-helical-tomotherapy
#14
G Narayanasamy, X Zhang, A Meigooni, X Liang, N Paudel, S Morrill, S Maraboyina, L Peacock, J Penagaricano
PURPOSE: The aim of this project is to study the therapeutic ratio (TR) for helical Tomotherapy (HT) based spatially fractionated radiotherapy (GRID). Estimation of TR was based on the linear-quadratic cell survival model by comparing the normal cell survival in a HT GRID to that of a uniform dose delivery in an open-field for the same tumor survival. METHODS: HT GRID plan was generated using a patient specific virtual GRID block pattern of non-divergent, cylinder shaped holes using MLCs...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048523/we-de-bra-09-fast-megavoltage-ct-imaging-with-rapid-scan-time-and-low-imaging-dose-in-helical-tomotherapy
#15
T Magome, A Haga, Y Takahashi, K Nakagawa, K Dusenbery, S Hui
PURPOSE: Megavoltage computed tomography (MVCT) imaging has been widely used for daily patient setup with helical tomotherapy (HT). One drawback of MVCT is its very long imaging time, owing to slow couch speed. The purpose of this study was to develop an MVCT imaging method allowing faster couch speeds, and to assess its accuracy for image guidance for HT. METHODS: Three cadavers (mimicking closest physiological and physical system of patients) were scanned four times with couch speeds of 1, 2, 3, and 4 mm/s...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048256/su-f-t-667-development-and-validation-of-dose-calculation-for-an-open-source-kv-treatment-planning-system-for-small-animal-radiotherapy
#16
S Prajapati, X Mo, B Bednarz, M Lawless, C Hammer, R Flynn, D Westerly, R Jeraj, T Mackie
PURPOSE: An open-source, convolution/superposition based kV-treatment planning system(TPS) was developed for small animal radiotherapy from previously existed in-house MV-TPS. It is flexible and applicable to both step and shoot and helical tomotherapy treatment delivery. For initial commissioning process, the dose calculation from kV-TPS was compared with measurements and Monte Carlo(MC) simulations. METHODS: High resolution, low energy kernels were simulated using EGSnrc user code EDKnrc, which was used as an input in kV-TPS together with MC-simulated x-ray beam spectrum...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047982/su-f-t-267-a-clarkson-based-independent-dose-verification-for-the-helical-tomotherapy
#17
H Nagata, H Hongo, D Kawai, R Takahashi, H Hashimoto, H Tachibana
PURPOSE: There have been few reports for independent dose verification for Tomotherapy. We evaluated the accuracy and the effectiveness of an independent dose verification system for the Tomotherapy. METHODS: Simple MU Analysis (SMU, Triangle Product, Ishikawa, Japan) was used as the independent verification system and the system implemented a Clarkson-based dose calculation algorithm using CT image dataset. For dose calculation in the SMU, the Tomotherapy machine-specific dosimetric parameters (TMR, Scp, OAR and MLC transmission factor) were registered as the machine beam data...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047842/su-f-t-420-dosimetry-comparison-of-advanced-external-beam-radiation-treatment-modalities-to-brachytherapy-treatments-in-patients-with-cervical-cancer
#18
U Mwidu, S Devic, M Shehadeh, M AlKafi, R Mahmood, B Moftah
PURPOSE: A retrospective comparison of dose distributions achievable by High dose rate brachytherapy (HDRBT), Helical TomoTherapy (TOMO), CyberKnife (CK) and RapidArc (RA) in locally advanced inoperable cervical cancer patients is presented. METHODS: Five patients with advanced stage cervical carcinoma were selected for this study after a full course of external beam radiotherapy (EBRT), chemotherapy and HDR Brachytherapy. To highlight any significant similarities/differences in dose distributions, high-risk clinical target volume (HRCTV) coverage, organs at risk (OAR) sparing, and machine specific delivery limitations, we used D90 (dose received by 90% of the volume) as the parameter for HRCTV coverage as recommended by the GEC-ESTRO Working Group...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047821/su-f-t-523-radiobiological-comparison-of-helical-tomotherapy-and-vmat-in-the-treatment-of-head-and-neck-tumors
#19
R Woods, P Mavroidis, M Lehman-Davis, M Kostich, T Cook, B Chera, S Das, J Lian
PURPOSE: This study aims at comparing the efficacy of Helical Tomotherapy (TOMO) and Volumetric Modulated Arc Therapy (VMAT) in producing highly conformal dose distributions in challenging head & neck cancer patients. Furthermore, to interpret the dosimetric findings into expected tissue response rates in order to estimate their clinical impact. METHODS: Seven patients were studied and for each patient two treatment plans (one TOMO and one VMAT) were created. Structures used for optimization were: high risk PTV, standard risk PTV, brainstem, spinal cord, parotid gland, larynx, mandible and surrounding tissue...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047751/su-f-t-456-tomotherapy-mlc-synchronization-and-leaf-open-time-measurements-using-arccheck
#20
B Yang, R Wong, W Lam, H Geng, K Cheung, S Yu
PURPOSE: To develop a practical method for routine QA of the MLC of a Tomotherapy unit using ArcCheck. METHODS: Two standard test plans were used in this study. One was a helical test, in which the central leaves No. 32 and 33 opened simultaneously for 277.8ms at projections centered at 0°, 120° and 240° gantry angles. The other test plan was a static test with the gantry angle set at 0°, 45°, 90° and 135° respectively and leaves No. 32 and 33 opened sequentially for total 20s which was further divided into eleven or ten segments at each beam angle...
June 2016: Medical Physics
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