scholarly journals Attenuation properties and percentage depth dose of tannin-based Rhizophora spp. particleboard phantoms using computed tomography (CT) and treatment planning system (TPS) at high energy x-ray beams

2016 ◽  
Author(s):  
M. F. Mohd Yusof ◽  
R. Abdullah ◽  
A. A. Tajuddin ◽  
R. Hashim ◽  
Bauk S.
Keyword(s):  
Computed Tomography ◽  
Treatment Planning ◽  
High Energy ◽  
Planning System ◽  
Treatment Planning System ◽  
X Ray ◽  
Percentage Depth Dose ◽  
Depth Dose

Two Quality Control Procedures on Radiotherapy Beam Calibration and Treatment Planning System Implementation

1998 ◽  
Vol 84 (2) ◽  
pp. 150-154 ◽  
Author(s):  
Angelo Piermattei ◽  
Luigi Azario ◽  
Stefania delle Canne ◽  
Andrea Fidanzio ◽  
Giovanni Palazzoni
Keyword(s):  
Quality Control ◽  
Treatment Planning ◽  
High Energy ◽  
Planning System ◽  
Treatment Planning System ◽  
Silicon Detectors ◽  
X Ray ◽  
Silicon Diode ◽  
Output Factors ◽  
Control Procedures

New challenging dosimetric approaches, such as narrow beams and 3D algorithms, are being used in radiotherapy. In this paper two quality control (QC) procedures are reported. The first one concerns the QC of the dosimetry of small x-ray beams, generally carried out by using silicon detectors. The comparison of dose values obtained by a silicon diode, a diamond detector, and radiochromic films shows that for x-ray beams of high energy, the silicon diode can give an overestimation of the output factors in phantom, up to 4%. This is due to the higher than unit density silicon diode and the surrounding envelope that restore the lateral electron equilibrium. About the 3D algorithms for breast treatment planning, a quality control test has been adopted to verify the accuracy of the computed dosimetry when “loss of scatter” occurs. The results show a sensible agreement (within 1.5%) between computed and experimental data.

scholarly journals Energy spectra considerations for synchrotron radiotherapy trials on the ID17 bio-medical beamline at the European Synchrotron Radiation Facility

2015 ◽  
Vol 22 (4) ◽  
pp. 1035-1041 ◽  
Author(s):  
Jeffrey C. Crosbie ◽  
Pauline Fournier ◽  
Stefan Bartzsch ◽  
Mattia Donzelli ◽  
Iwan Cornelius ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Synchrotron Radiation ◽  
Treatment Planning ◽  
European Synchrotron Radiation Facility ◽  
Planning System ◽  
Energy Spectra ◽  
Treatment Planning System ◽  
X Ray ◽  
Depth Dose ◽  
Cylindrical Ionization Chamber

The aim of this study was to validate the kilovoltage X-ray energy spectrum on the ID17 beamline at the European Synchrotron Radiation Facility (ESRF). The purpose of such validation was to provide an accurate energy spectrum as the input to a computerized treatment planning system, which will be used in synchrotron microbeam radiotherapy trials at the ESRF. Calculated and measured energy spectra on ID17 have been reported previously but recent additions and safety modifications to the beamline for veterinary trials warranted a fresh investigation. The authors used an established methodology to compare X-ray attenuation measurements in copper sheets (referred to as half value layer measurements in the radiotherapy field) with the predictions of a theoretical model. A cylindrical ionization chamber in air was used to record the relative attenuation of the X-ray beam intensity by increasing thicknesses of high-purity copper sheets. The authors measured the half value layers in copper for two beamline configurations, which corresponded to differing spectral conditions. The authors obtained good agreement between the measured and predicted half value layers for the two beamline configurations. The measured first half value layer was 1.754 ± 0.035 mm Cu and 1.962 ± 0.039 mm Cu for the two spectral conditions, compared with theoretical predictions of 1.763 ± 0.039 mm Cu and 1.984 ± 0.044 mm Cu, respectively. The calculated mean energies for the two conditions were 105 keV and 110 keV and there was not a substantial difference in the calculated percentage depth dose curves in water between the different spectral conditions. The authors observed a difference between their calculated energy spectra and the spectra previously reported by other authors, particularly at energies greater than 100 keV. The validation of the beam spectrum by the copper half value layer measurements means the authors can provide an accurate spectrum as an input to a treatment planning system for the forthcoming veterinary trials of microbeam radiotherapy to spontaneous tumours in cats and dogs.

scholarly journals Reconstrução de Espectros de Raios X de Aceleradores Lineares Clínicos usando o Método de Recozimento Simulado Generalizado

2016 ◽  
Vol 10 (2) ◽  
pp. 2
Author(s):  
John Peter Oyardo Manrique ◽  
Alessandro Martins Da Costa
Keyword(s):  
Monte Carlo ◽  
Simulated Annealing ◽  
Treatment Planning ◽  
Planning System ◽  
Treatment Planning System ◽  
Percentage Depth Dose ◽  
Depth Dose

A distribuição espectral de raios X de megavoltagem utilizados em departamentos de radioterapia é uma grandeza fundamental a partir da qual, em princípio, todas as informações requeridas relevantes para tratamentos de radioterapia podem ser determinadas. Para o calculo das doses administradas ao paciente que faz radioterapia se usam sistemas de planejamento de tratamento (TPS, do inglês Treatment Planning System), que fazem uso de algoritmos de convolução e superposição os quais requerem um conhecimento prévio do espectro de fluência de fótons para realizar o cálculo acurado das doses tridimensionais e assim assegurar uma melhor probabilidade de controle tumoral mantendo baixa a probabilidade de complicações do tecido normal. Neste trabalho foi obtido o espectro de fluência de fótons de raios X de um acelerador linear clínico SIEMENS ONCOR de 6 MV, usando um método de caráter inverso para a reconstrução dos espectros, a partir das curvas de transmissão de fótons medidas para diferentes espessuras de alumínio; o método usado para a reconstrução dos espectros é uma técnica estocástica conhecida como recozimento simulado generalizado (GSA, do inglês Generalized Simulated Annealing), baseado no trabalho da estatística de quase equilíbrio de Tsallis.  Para a validação dos espectros reconstruídos foram calculadas as curvas de porcentagem de dose em profundidade (PDD, do inglês Percentage Depth Dose) para a energia de 6 MV do acelerador, usando simulação Monte Carlo com o código PENELOPE, e a partir da PDD se fez o cálculo o índice de qualidade do feixe TPR20/10.

scholarly journals Application of treatment planning system assisted large-aperture computed tomography simulator in percutaneous biopsy: initial experience by a radiation therapist

2020 ◽  
Author(s):  
Xiaoyi Lin ◽  
Jun-qiang Hong ◽  
Shui-ying Luo ◽  
You-qun Lai ◽  
Yong-liang Dai ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Success Rate ◽  
Treatment Planning ◽  
Percutaneous Biopsy ◽  
Lymph Node Biopsy ◽  
Planning System ◽  
Treatment Planning System ◽  
Initial Experience ◽  
Ct Guided ◽  
Large Aperture

Abstract Background and purpose To evaluate the application of treatment planning system (TPS) assisted large-aperture computed tomography (CT) simulator in percutaneous biopsy, and report our initial experience of the accuracy and safety of this procedure.Methods From November 2018 to December 2019, treatment planning system assisted large-aperture CT simulator guided percutaneous biopsy was performed on 38 cases, with 34 of percutaneous lung biopsy, three of abdominal lesions biopsy, and one case of deep supraclavicular lymph node biopsy. The major results including planned and actual puncture parameters, the success rate, pathological information and complications were recorded. The analyses of puncture accuracy were accomplished by pared-t test and Wilcoxon rank sum test. And the risk factors of puncture accuracy and complications were further identified.Results The entire cohort achieved one-time success of biopsy. No significant differences were presented between planned and actual puncture depth and direction (P = 0.436 and 0.382), indicating the precision of the process. And the pulmonary puncture location was related to the accuracy of puncture direction (P = 0.033). Biopsy specimens were successfully obtained in 38 cases. The diagnostic rate of malignancy was 76%, of which 80% for initial treatment group and 69% for treated group, respectively. For patients with pulmonary biopsy, 12 had minor pneumothorax and 2 progressed to massive pneumothorax. Only three cases suffered needle track bleeding, and no other complications were observed. Additionally, the regression analysis found a significant correlation between puncture angle and the incidence of pneumothorax (P = 0.027).Conclusions TPS assisted large-aperture CT simulator improved the procedure of percutaneous biopsy by combining the advantages of radiotherapy specialty. The initial results suggested the increase of puncture accuracy and success rate, with satisfactory safety simultaneously. It might offer new insights into the field of CT-guided percutaneous biopsy.

scholarly journals Initial Validation of Proton Dose Calculations on SPR Images from DECT in Treatment Planning System

2020 ◽  
Vol 7 (2) ◽  
pp. 51-61
Author(s):  
Sina Mossahebi ◽  
Pouya Sabouri ◽  
Haijian Chen ◽  
Michelle Mundis ◽  
Matthew O'Neil ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Treatment Planning ◽  
Effective Atomic Number ◽  
Dose Calculation ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Relative Electron ◽  
Treatment Plans ◽  
Proton Dose

Abstract Purpose To investigate and quantify the potential benefits associated with the use of stopping-power-ratio (SPR) images created from dual-energy computed tomography (DECT) images for proton dose calculation in a clinical proton treatment planning system (TPS). Materials and Methods The DECT and single-energy computed tomography (SECT) scans obtained for 26 plastic tissue surrogate plugs were placed individually in a tissue-equivalent plastic phantom. Relative-electron density (ρe) and effective atomic number (Zeff) images were reconstructed from the DECT scans and used to create an SPR image set for each plug. Next, the SPR for each plug was measured in a clinical proton beam for comparison of the calculated values in the SPR images. The SPR images and SECTs were then imported into a clinical TPS, and treatment plans were developed consisting of a single field delivering a 10 × 10 × 10-cm3 spread-out Bragg peak to a clinical target volume that contained the plugs. To verify the accuracy of the TPS dose calculated from the SPR images and SECTs, treatment plans were delivered to the phantom containing each plug, and comparisons of point-dose measurements and 2-dimensional γ-analysis were performed. Results For all 26 plugs considered in this study, SPR values for each plug from the SPR images were within 2% agreement with measurements. Additionally, treatment plans developed with the SPR images agreed with the measured point dose to within 2%, whereas a 3% agreement was observed for SECT-based plans. γ-Index pass rates were > 90% for all SECT plans and > 97% for all SPR image–based plans. Conclusion Treatment plans created in a TPS with SPR images obtained from DECT scans are accurate to within guidelines set for validation of clinical treatment plans at our center. The calculated doses from the SPR image–based treatment plans showed better agreement to measured doses than identical plans created with standard SECT scans.

scholarly journals The Commissioning and Validation of EclipseTM Treatment Planning System on a Varian VitalBeamTM Medical Linear Accelerator for Photon and Electron Beams

2021 ◽  
Author(s):  
Samira Yazdani ◽  
Fateme Shirani Takabi ◽  
Abolfazl Nickfarjam
Keyword(s):  
Treatment Planning ◽  
Linear Accelerator ◽  
Electron Beams ◽  
Planning System ◽  
Treatment Planning System ◽  
Patient Treatment ◽  
Depth Dose ◽  
Tps Commissioning ◽  
Calculated Dose ◽  
Output Factors

Purpose: Commissioning of a linear accelerator is a process of acquiring a set of data used for patient treatment. This article presents the beam data measurement results from the commissioning of a VitalBeamTM linac. Materials and Methods: Dosimetric properties for 6,10, and 15 MV photon beams and 6, 9, 12, and 16 MeV electron beams have been performed. Parameters, including Percentage Depth Dose (PDD), depth dose profile, symmetry, flatness, quality index, output factors, and the vital data for Treatment Planning System (TPS) commissioning were measured. The imported data were checked by CIRS phantom accordingly to IAEA TRS-430, TECDOC. Eight different positions of CIRS phantom CT were planned and treated. Finally, the calculated dose at a determined position was compared with measuring data to TPS validation. Results: After comparing 84 points in a different plan, the 83 points were in agreement with the criteria, and just for one point in 15 MV failed. Conclusion: Commissioning of dose and field flatness and symmetry are in tolerance intervals given by Varian. This proves that the studied lines meet the specification and can be used in clinical practice with all available electron and photon energies.

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