bluuebunny/crossref_metadata_2025_split huggingface dataset:
SU‐E‐T‐348: Verification MU Calculation for Conformal Radiotherapy with Multileaf Collimator Using Report AAPM TG 114
Authors: Adrada A , Tello Z , Medina L , Garrigo E , Venencia D 
Published: July 2014

Purpose:The purpose of this work was to develop and validate an open source independent MU dose calculation software for 3D conformal radiotherapy with multileaf high and low resolution according to the report of AAPM TG 11Methods:Treatment plans were done using Iplan v4.5 BrainLAB TPS. A 6MV photon beam produced by Primus and Novalis linear accelerators equipped with an Optifocus MLC and HDMLC, respectively. TPS dose calculation algorithms were pencil beam and Monte Carlo. 1082 treatments plans were selected for the study. The algorithm was written in free and open source CodeBlocks C++ platform. Treatment plans were imported by the software using RTP format. Equivalent size field is obtained from the positions of the leaves; the effective depth of calculation can be introduced by TPS's dosimetry report or automatically calculated starting from SSD. The inverse square law is calculated by the 3D coordinates of the isocenter and normalization point of the treatment plan. The dosimetric parameters TPR, Sc, Sp and WF are linearly interpolated.Results:1082 plans of both machines were analyzed. The average uncertainty between the TPS and the independent calculation was −0.43% ± 2.42% [−7.90%, 7.50%]. Specifically for the Primus the variation obtained was −0.85% ± 2.53% and for the Novalis 0.00% ± 2.23%. Data show that 94.8% of the cases the uncertainty was less than or equal to 5%, while 98.9% is less than or equal to 6%.Conclusion:The developed software is appropriate for use in calculation of UM. This software can be obtained upon request.
SU‐E‐T‐349: Verification of a Monte Carlo Simulation Tool as a Second Check for TomoTherapy Treatment Planning
Authors: Yuan J , Chen Q , Zheng Y , Sohn J , Wessels B 
Published: July 2014

Purpose:To verify a virtual source model used in Monte Carlo (MC) TomoTherapy simulations and to provide a tool for the dose distribution second check for TomoTherapy treatment planning.Methods:Published studies adopted the full MC model to simulate helical TomoTherapy which use phase space files (PSFs) at different scoring planes to facilitate patient dose calculations. We have developed a simple virtual source model (VSM) based on the commissioning data of helical TomoTherapy unit which can be exported from the treatment planning station (TPS). To calculate the patient dose distribution, TPS‐generated sinograms are extracted from archived patient XML files and fluence maps are created by incorporating the openclose leaf time with leaf filter, jaw penumbra, and leaf latency. The VSM has been validated for various geometrical set‐ups including open fields, heterogeneous media and clinical DQA cases.Results:Good agreement was obtained between our VSM and a published full MC model for the test case of heterogeneous media. For the complex clinical head and neck (HN) case, the MC simulation of the DQA plan agreed with the film measurement with 98% of planar dose pixels passing the 2%/2 mm gamma value test. For the patient treatment plan itself, the MC simulation showed comparable DVHs for the planning target volumes (PTVs) and organs‐at‐risk (OARs). Deviations observed were consistent with literature.Conclusion:The proposed VSM can be used in the MC method to accurately simulate the patient dose distributions for helical TomoTherapy.
SU‐E‐T‐352: Why Is the Survival Rate Low in Oropharyngeal Squamous Cell Carcinoma?
Authors: Huang Z , Liu T , Feng Y , Rasmussen K , Rice J , Stephenson S , Ferreira Maria C , Yuh K , Wang R , Lo S , Grecula J , Mayr N , Yuh W 
Published: July 2014

Purpose:Tumors are composed of a large number of clonogens that have the capability of indefinite reproduction. Even when there is complete clinical or radiographic regression of the gross tumor mass after treatment, tumor recurrence can occur if the clonogens are not completely eradicated by radiotherapy. This study was to investigate the colonogen number and its association with the tumor control probability (TCP) in oropharyngeal squamous cell carcinoma (OSCCA).Methods:A literature search was conducted to collect clinical information of patients with OSCCA, including the prescription dose, tumor volume and survival rate. The linear‐quadratic (LQ) model was incorporated into TCP model for clinical data analysis. The total dose ranged from 60 to 70 Gy and tumor volume ranged from 10 to 50 cc. The TCP was calculated for each group according to tumor size and dose. The least χ2 method was used to fit the TCP calculation to clinical data while other LQ model parameters (α, β) were adopted from the literature, due to the limited patient data.Results:A total of 190 patients with T2–T4 OSCCA were included. The association with HPV was not available for all the patients. The 3‐year survival rate was about 82% for T2 squamous cell carcinoma and 40% for advanced tumors. Fitting the TCP model to the survival data, the average clonogen number was 1.56×1012. For the prescription dose of 70 Gy, the calculated TCP ranged from 40% to 90% when the tumor volume varied from 10 to 50 cc.Conclusion:Our data suggests variation between the clonogen number and TCP in OSCCA. Tumors with larger colonogen number tend to have lower TCP and therefore dose escalation above 70 Gy may be indicated in order to improve the TCP and survival rate. Our result will require future confirmation with a large number of patients.
SU‐E‐T‐485: Investigation of a Synthetic Diamond Detector for Tomotherapy Dosimetry
Authors: Knill C , Zakjevskii V , Nalichowski A , Halford R , Snyder M , Zhuang L , Burmeister J 
Published: July 2014

Purpose:Tomotherapy treatments are characterized by rotational deliveries of flattening‐filter free fields resulting in high‐gradient dose distributions. Small volume, rotationally independent detectors are needed for accurate dosimetry. PTWs microDiamond detector, with its small sensitive volume (0.004mm3), could potentially be an ideal detector for Tomotherapy. The microDiamond detector was tested against a small volume Exradin A1SL ion chamber for Tomotherapy open‐field and IMRT commissioning measurements.Methods:Custom detector holders were fabricated to allow A1SL and microDiamond measurements in the Tomotherapy Cheese phantom and a square solid water phantom. The microDiamond rotational dependence within the Tomotherapy phantom was tested by incrementally rotating the detector in between static‐gantry angle Tomotherapy irradiations. Longitudinal Tomotherapy profiles, for all field sizes, were measured with the microDiamond and A1SL detectors at 1.5cm depth in the square phantom, and compared to film. Detector axes were aligned parallel to table motion. Per TG‐119 recommendations, both detectors were calibrated to known doses in phantoms and used to measure high‐dose points in TG‐119 H&N and Prostate plans. The measurements were compared to the treatment planning system and subsequently compared to published TG‐119 confidence limits.Results:The microDiamond angular dependence was less than 0.5%. The average difference between the detectors and film‐measured longitudinal profile 80–20% penumbras were 0.03+/‐0.04mm and 1.36+/‐0.22mm for the microDiamond and A1SL, respectively. The average difference between the detector and filmmeasured field sizes were 0.07+/‐0.01mm and 0.09+/‐0.02mm for the microDiamond and A1SL, respectively. The measured confidence limits were 0.023 and 0.015 for microDiamond and A1SL, respectively. TG‐119 reported a confidence limit of 0.034.Conclusion:The microDiamond measured open‐field longitudinal Tomotherapy profiles more closely resembled film measurements, compared with the A1Sl chamber. Furthermore, the microDiamond was shown to have low angular dependence and both detectors were able to accurately measure the highdose points in TG‐119 H&N and prostate plans.Our institution has research grants with PTW.
SU‐E‐T‐494: A MOSFET‐Based In‐Vivo Dosimetry System for MR Image‐Guided Radiation Therapy (MR‐IGRT)
Authors: Knutson N , Li H , Rodriguez V , Hu Y , Kashani R , Wooten H , Tanderup K , Mutic S , Green O 
Published: July 2014

Purpose:To determine if a MOSFET based in‐vivo dosimetry system can be used for patients undergoing MR‐IGRT.Methods:Standard and high sensitivity MOSFET detectors were used for in‐field and out‐of‐field measurements respectively. The systems were benchmarked and calibrated against a calibrated ionization chamber on a standard 6 MV linear accelerator, and then on the MR‐IGRT system. Known doses were delivered to a water phantom with the MOSFETs placed between the top of the phantom and underneath a layer of bolus and water equivalent plastic, using a 6 MV beam and a 6 0Co MR‐IGRT beam. The latter was performed with and without real‐time MRI‐guidance during the beam delivery (MRIGRT).Results:The in‐field dosimeter response was linear from 50‐500 cGy with little evidence of energy dependence or change in response due to the permanent static magnetic field of the MR‐IGRT system. The detector response varied by < 2% between 6 MV and 6 0Co without image guided delivery. The out‐of‐field dosimeter response was linear from 1‐50 cGy; however the detectors did display dose rate and energy dependence as the response varied by > 20% depending on distance from isocenter used during calibration. Therefore, to use the dosimeters for out‐of‐field measurements they must be calibrated out‐of‐field. Regardless of the detector orientation in the coronal plan, the response of the MOSFETs during MRI‐guided delivery increased by 5% due to induced currents from the dynamic magnetic field present with image guidance. During the MRI‐guided delivery, some loss in image quality was seen when the MOSFETs were present in the imaging plane. This was mitigated by using a handheld reader without a transmitting wireless receiver.Conclusion:A MOSFET‐based in‐vivo dosimetry system can be used for patients receiving MR‐IGRT; however the change in detector response due to the dynamic magnetic field requires a special calibration.
SU‐E‐T‐499: Comparison of Measured Tissue Phantom Ratios (TPR) Against Calculated From Percent Depth Doses (PDD) with and Without Peak Scatter Factor (PSF) in 6MV Open Beam
Authors: Narayanasamy G , Cruz W , Breton C , Gutierrez Alonso , Mavroidis Panayiotis , Papanikolaou N , Stathakis S 
Published: July 2014

Purpose:To examine the accuracy of measured tissue phantom ratios (TPR) values with TPR calculated from percentage depth dose (PDD) with and without peak scatter fraction (PSF) correction.Methods:For 6MV open beam, TPR and PDD values were measured using PTW Semiflex (31010) ionization field and reference chambers (0.125cc volume) in a PTW MP3‐M water tank. PDD curves were measured at SSD of 100cm for 7 square fields from 3cm to 30cm. The TPR values were measured up to 22cm depth for the same fields by continuous water draining method with ionization chamber static at 100cm from source. A comparison study was performed between the (a) measured TPR, (b) TPR calculated from PDD without PSF, (c) TPR calculated from PDD with PSF and (d) clinical TPR from RadCalc (ver 6.2, Sun Nuclear Corp).Results:There is a field size, depth dependence on TPR values. For 10cmx10cm, the differences in surface dose (DDs), dose at 10cm depth (DD10) <0.5%; differences in dmax (Ddmax) <2mm for the 4 methods. The corresponding values for 30cmx30cm are DDs, DD10 <0.2% and Ddmax<3mm. Even though for 3cmx3cm field, DDs and DD10 <1% and Ddmax<1mm, the calculated TPR values with and without PSF correction differed by 2% at >20cm depth. In all field sizes at depths>28cm, (d) clinical TPR values are larger than that from (b) and (c) by >3%.Conclusion:Measured TPR in method (a) differ from calculated TPR in methods (b) and (c) to within 1% for depths < 28cm in all 7 fields in open 6MV beam. The dmax values are within 3mm of each other. The largest deviation of >3% was observed in clinical TPR values in method (d) for all fields at depths < 28cm.
SU‐E‐T‐503: Development of a Software Tool for Verification of Delivered Tomotherapy Plans Using the Tomo Log File
Authors: Xing A , Deshpande S , Arumugam S , George A , Holloway L , Goozee G 
Published: July 2014

Purpose:The data receive server (DRS) in the Tomotherapy Unit records planned and actually delivered plan parameters for each treatment into a log file. The purpose of this study was to develop a software tool using the log file for verification of the patient plan delivered during treatment.Methods:A software tool, TomoPQA, was developed using the Python programming language. The software was implemented using object‐oriented methodology and modular design. The program has three built‐in modules: Read‐in module for loading the log file, analysis module for analyzing the log file and reporting module for producing a PDF report.Results:The developed software tool can be used to monitor and check the following plan parameters during patient treatment: (1) planned and actual field width; (2) planned and actual treatment time; (3) planned and actual couch speed; (4) planned and actual gantry speed; (4) planned and actual setup position. The software shows the difference between these parameters as a graphic plot against each treatment fraction in a PDF report for easy review or these values can be exported to an excel file. The program can process a 100M byte log file and produce a report in the order of one minute and can run on Windows, Linux or Mac platforms as a standalone program. A server version of this program can also be implemented for full automation of the log file processing, generation of the PDF report and also has the potential for an automated email if given values are out of tolerance.Conclusion:A QA software tool has been developed for in‐vivo quality assurance of treatment delivered on a Tomotherapy Unit. This tool provides an independent verification of the difference between actual delivered and planned parameters during treatment.
SU‐E‐T‐506: Dosimetric Verification of Photon MLC Delivered Electron Fields for Implementing MERT On An Artiste Linac
Authors: Jin L , Eldib A , Fan J , Li J , Wang L , Ma C 
Published: July 2014

Purpose:To verify the dose accuracy of photon MLC delivered electron fields for implementing energy‐intensity modulated electron radiotherapy (MERT) on an Artiste linac.Methods:It was proposed to deliver MERT on an Artiste linac at a short SSD (60 cm) to reduce beam penumbra caused by electron scatters. An in‐house developed Monte Carlo (MC)‐based dose calculation/optimization planning code was used for treatment planning. Our previous study showed that the measured dose distribution of a breast plan showed good agreement with the calculations in low‐medium dose regions while the differences in high dose regions were outstanding. A continuous work found that the discrepancy is mainly caused by improper modeling in MC for the single focused MLC in the Artiste which was simplified as double focused in the previous MC simulations. With this remodeled MLC in the calculations, an energy‐intensity modulated electron plan using 6, 9, 12 and 15 MeV was generated for a breast treatment on a breast phantom at a 60 cm SSD and recalculated regarding a solid water phantom. For a test study, four of MLC segments (each with a different energy) generated in the plan were delivered to the phantom and a film measurement was performed at the depth of 2 cm. The measured 2D dose distribution was then compared with calculations.Results:For composite doses of the four segments, measured 2D dose distributions overall agree well with the calculations (3mm/3%) in most area. The separate measurement for a single MLC segment for each of energies also showed the consistence with the calculations.Conclusion:After remodeling MLC in the MC calculations, the measured dose distribution for a subset of MLC segments from a MERT plan showed good agreement. Further detailed verification for the full plan will be the work in the next step.
Preparation of Aligned ZnO Nanorod Arrays on Sn-Doped ZnO Thin Films by Sonicated Sol-Gel Immersion Fabricated for Dye-Sensitized Solar Cell
Authors: Saurdi I. , Mamat M. H. , Malek M. F. , Rusop M. 
Published: July 2014

Aligned ZnO Nanorod arrays are deposited on the Sn-doped ZnO thin film via sonicated sol-gel immersion method. The structural, optical, and electrical properties of the Sn-doped ZnO thin films were investigated. Results show that the Sn-doped ZnO thin films with small grain size (~20 nm), high average transmittance (96%) in visible region, and good resistivity7.7 × 102 Ω·cm are obtained for 2 at.% Sn doping concentration. The aligned ZnO nanorod arrays with large surface area were also obtained for 2 at.% Sn-doped ZnO thin film. They were grown on sol-gel derived Sn-doped ZnO thin film, which acts as a seed layer, via sonicated sol-gel immersion method. The grown aligned ZnO nanorod arrays show high transmittance at visible region. The fabricated dye-sensitised solar cell based on the 2.0 at.% Sn-doped ZnO thin film with aligned ZnO nanorod arrays exhibits improved current density, open-circuit voltage, fill factor, and conversion efficiency compared with the undoped ZnO and 1 at.% Sn-doped ZnO thin films.
Systematics and biogeography of Hemidactylus homoeolepis Blanford, 1881 (Squamata: Gekkonidae), with the description of a new species from Arabia
Authors: VASCONCELOS RAQUEL , CARRANZA SALVADOR 
Published: July 2014

A new species of gecko of the genus Hemidactylus (Squamata: Gekkonidae) is described from Oman and extreme eastern Yemen. Hemidactylus minutus sp. nov. is characterized morphologically by its very small size, being the smallest Hemidactylus in mainland Arabia, absence of enlarged tubercles anywhere on the body, expanded subcaudal scales beginning some way from tail base, number of preanal pores, number of lamellae under the first and fourth toes, and weakly contrasted black and white banded pattern on the ventral part of tail. It is also genetically distinct from H. homoeolepis to which it has previously been referred, and from all other closely related Hemidactylus from the arid clade in DNA sequence data for mitochondrial (12S, cyt b, ND4) and three nuclear (RAG1, MC1R, c‑mos) markers. An adult female from southern Yemen and a badly preserved juvenile from southwestern Saudi Arabia previously assigned to H. homoeolepis are morphologically differentiated from this species and from H. minutus sp. nov. and temporarily referred to as Hemidactylus sp. 12 and Hemidactylus sp. 13, respectively until more specimens are collected and analyzed. Up to now, H. homoeolepis was the only non-endemic native species of the Socotra Archipelago. With the description of H. minutus sp. nov., all native reptile species of Socotra are now endemic, such that this archipelago has one with the highest number of endemic reptiles in relation to its small size. In addition, as a result of our taxonomic change, the area of occupancy and extent of occurrence of H. homoeolepis have changed dramatically and thus its conservation status should be updated. Although H. minutus sp. nov. seems widely distributed and relatively abundant, its conservation status should also be re-evaluated.
Game Mechanics in the Design of a Collaborative 3D Serious Game
Authors: Oksanen Kimmo , Hämäläinen Raija 
Published: July 2014

Background This article investigates the potential of utilizing game mechanics in designing 3D serious games for Computer-Supported Collaborative Learning (CSCL) and attempt to produce new information about designing collaborative serious games. Aim This article has two aims: First, to clarify how theoretical knowledge of collaborative learning was related to game design in previous studies; and, second, to design a collaborative serious game based on theoretical knowledge of collaborative learning and game design. Results The reviewed studies revealed the potential of using collaborative games in education. However, they showed that collaborative learning games were typically designed only from pedagogical perspective. Thus, integrating educational theory and game design perspectives was rare. Therefore, we argue that collaborative serious games do not necessarily take full advantage of their potential. Conclusion The main contribution of this article is to present seven ways to utilize game mechanics in order to create favorable conditions for collaborative learning and to structure players’ actions to boost social interaction and collaborative activities. This article concludes with an example of taking advantage of game mechanics in the design of a collaborative serious game. This article also uses event-charts to demonstrate the practical implementation of game mechanics in three multiplayer puzzles.
Cultural diversity and subjective well-being
Authors: Longhi Simonetta 
Published: July 2014

AbstractThis paper analyses the impact that diversity has on life satisfaction of people living in England. In England, and in many other countries, local communities are becoming more diverse in terms of country of birth, ethnicity and religion of residents, with unclear consequences on the well-being of people living in these communities. The results suggest that white British people living in diverse areas have on average lower levels of life satisfaction than those living in areas where diversity is low, while there is no correlation on average between diversity and life satisfaction for non-white British people and foreign born.JEL codesJ31, J61, R23
PLDA in the i-supervector space for text-independent speaker verification
Authors: Jiang Ye , Lee Kong Aik , Wang Longbiao 
Published: July 2014

Abstract
In this paper, we advocate the use of the uncompressed form of i-vector and depend on subspace modeling using probabilistic linear discriminant analysis (PLDA) in handling the speaker and session (or channel) variability. An i-vector is a low-dimensional vector containing both speaker and channel information acquired from a speech segment. When PLDA is used on an i-vector, dimension reduction is performed twice: first in the i-vector extraction process and second in the PLDA model. Keeping the full dimensionality of the i-vector in the i-supervector space for PLDA modeling and scoring would avoid unnecessary loss of information. We refer to the uncompressed i-vector as the i-supervector. The drawback in using the i-supervector with PLDA is the inversion of large matrices in the estimation of the full posterior distribution, which we show can be solved rather efficiently by portioning large matrices into smaller blocks. We also introduce the Gaussianized rank-norm, as an alternative to whitening, for feature normalization prior to PLDA modeling. We found that the i-supervector performs better during normalization. A better performance is obtained by combining the i-supervector and i-vector at the score level. Furthermore, we also analyze the computational complexity of the i-supervector system, compared with that of the i-vector, at four different stages of loading matrix estimation, posterior extraction, PLDA modeling, and PLDA scoring.