bluuebunny/crossref_metadata_2025 huggingface dataset:
Inpatient Gamma-Hydroxybutyrate Detoxification: A Case Report Describing Day-to-day Therapeutic Management
Authors: von Theobald Louis , Rousselet Morgane , Cholet Jennyfer , Debar Hélène , Boels David , Victorri-Vigneau Caroline , Grall-Bronnec Marie
Published: February 2017

Background:

Gamma-hydroxybutyrate (GHB) is a synthetic drug increasingly used by consumers of psychoactive substances. The sought after psychoactive effects of GHB have resulted in an increase in recreational use in Europe. GHB is considered to have a high dependence potential, and abrupt discontinuation after long-term use can result in a severe withdrawal syndrome. Despite a large number of publications related to GHB withdrawal and detoxification, to date, no evidence-based protocol or consensual international therapeutic guidelines are available (over and above the administration of benzodiazepines). We hereby present a day-to-day description of inpatient GHB detoxification management, from admission to discharge.

Case Summary:

This case report pertains to a 47-year-old patient hospitalized for a severe GHB use disorder. The patient had independently made several unsuccessful attempts to stop GHB use. Following to these failures, the patient was oriented to our addiction department for inpatient detoxification. Withdrawal symptoms appeared 4 hours after the last dose of GHB, and consisted of diaphoresis, coenesthetic hallucinations, tremors, motor instability, tachycardia, and a hypertensive peak. Symptoms were successfully managed with diazepam titration and nonpharmacological treatment. The duration of hospitalization was 13 days. At discharge, detoxification was complete and the patient was engaged in relapse prevention therapy. Three months after discharge, the patient had maintained abstinence.

Conclusions:

GHB withdrawal, which can be severe, is better prevented or attenuated by daily medical monitoring and adjustment of treatment dosage. Failure of outpatient detoxification should be included in the indication criteria in the guidelines for inpatient detoxification.
Pain Sensation During Colposcopy and Cervical Biopsy, With or Without Local Anesthesia: A Randomized Trial
Authors: Kiviharju Mari , Kalliala Ilkka , Nieminen Pekka , Dyba Tadeusz , Riska Annika , Jakobsson Maija
Published: February 2017

Objective

The aim of the study was to determine whether an injection of a local anesthetic is more painful than a cervical punch biopsy without local anesthesia.

Materials and Methods

The study was a randomized controlled trial, conducted at the Helsinki University Central Hospital. It consisted of 204 women referred for colposcopic assessments. Half of them were randomized to receive local anesthesia before their cervical punch biopsies. After the injection of the local anesthetic, the cervical punch biopsy, and the endocervical curettage, the women scored their actual pain using a 10-cm visual analog scale (VAS).

To measure the difference in VAS scores between two groups, a linear regression model was used. Binomial regression model was applied for comparing the probability of experiencing unbearable pain between the groups. Applying modeling approach allowed also for proper adjustment for other potential risk factors.

Results

The mean VAS score for the injection of the local anesthetic was 2.7, the VAS score for the cervical punch biopsy without local anesthesia was 3.5, and the difference was 0.8 (p = .017; 95% CI = 0.1–1.5). The mean VAS for the biopsy with local anesthesia was 0.8, which was significantly lower than the mean VAS for the biopsy without local anesthesia (difference = 2.7; p < .001; 95% CI = 2.2–3.3). The relative risk for experiencing moderate or severe pain (VAS ≥ 5) was 0.6 (p = .03; 95% CI = 0.3–0.9) for the injection of local anesthetic versus the biopsy without local anesthesia.

Conclusions

Injection of a local anesthetic for colposcopy is less painful than biopsies without local anesthesia, and local anesthesia decreases the pain perceived.
Light-induced Hemiplegia, an Atypical Case of Retinal Steal Syndrome
Authors: Kerek David , Al Kasab Sami , Antonucci Michael U. , Turner Raymond D. , Turan Tanya N.
Published: February 2017

Atherosclerosis affecting the carotid arteries accounts for up to 20% of ischemic strokes 1. The clinical effects of atherosclerotic occlusive disease vary according to multiple factors, one of which is collateral circulation. In response to a chronic decrease in cerebral perfusion from atherosclerotic occlusion, alternative flow pathways, or collaterals, develop in a variety of patterns. In the setting of carotid occlusion, flow from the Circle of Willis, if complete, often comprises the main cerebral collateral network. In addition, contributions from leptomeningeal and extracranial to intracranial collaterals may develop. In the latter, reversal of flow in the ophthalmic artery can reconstitute to restore supraclinoid internal carotid artery flow. We report a case of the unusual sequela of a collateral flow pattern via the ophthalmic artery that induces a unique retinal steal phenomenon.
Are Calorie Counting Apps Ready to Replace Traditional Dietary Assessment Methods?
Authors: Gilhooly Cheryl H.
Published: February 2017

There are multiple reasons individuals, health professionals, and nutrition researchers have for tracking dietary intake. Traditional dietary assessment methods are labor intensive and rely on quality-controlled food composition databases with minimal missing data. In today's mobile app environment, there are many options for tracking dietary intake using a diet tracking app. Depending on the purpose of the dietary tracking, there are multiple functions of these programs to consider when deciding whether these apps are ready to replace traditional methods of dietary assessment.
Herbs, Spices, and Flavoring Agents
Authors: Grivetti Louis E.
Published: February 2017

Each plant has a story, one that reflects the distance traveled from its ancient geographical origins, from wild to domesticated forms, and ultimately to culinary, cultural, medical, and social uses in the 21st century. Herbs and spices have taken these winding historical paths, and the journeys reflect myriad uses by widely different cultures because they ultimately reach our kitchens, serving plates, and palates.
The mechanism of sphingolipid processing revealed by a GALC-SapA complex structure
Authors: Hill Chris H. , Cook Georgia M. , Spratley Samantha J. , Graham Stephen C. , Deane Janet E.
Published: February 2017

Sphingolipids are essential components of cellular membranes and defects in their synthesis or degradation cause severe human diseases. The efficient degradation of sphingolipids in the lysosome requires lipid-binding saposin proteins and hydrolytic enzymes. The glycosphingolipid galactocerebroside is the primary lipid component of the myelin sheath and is degraded by the hydrolase β-galactocerebrosidase (GALC). This enzyme requires the saposin SapA for lipid processing and defects in either of these proteins causes a severe neurodegenerative disorder, Krabbe disease. Here we present the structure of a glycosphingolipid-processing complex, revealing how SapA and GALC form a heterotetramer with an open channel connecting the enzyme active site to the SapA hydrophobic cavity. This structure defines how a soluble hydrolase can cleave the polar glycosyl headgroups of these essential lipids from their hydrophobic ceramide tails. Furthermore, the molecular details of this interaction reveal how specificity of saposin binding to hydrolases is encoded.
A microfluidic biodisplay
Authors: Volpetti Francesca , Petrova Ekaterina , Maerkl Sebastian J.
Published: February 2017

Synthetically engineered cells are powerful and potentially useful biosensors, but it remains problematic to deploy such systems due to practical difficulties and biosafety concerns. To overcome these hurdles, we developed a microfluidic device that serves as an interface between an engineered cellular system, environment, and user. We created a biodisplay consisting of 768 individually programmable biopixels and demonstrated that it can perform multiplexed, continuous sampling. The biodisplay detected 10 µg/l sodium-arsenite in tap water using a research grade fluorescent microscope, and reported arsenic contamination down to 20 µg/l with an easy to interpret “skull and crossbones” symbol detectable with a low-cost USB microscope or by eye. The biodisplay was designed to prevent release of chemical or biological material to avoid environmental contamination. The microfluidic biodisplay thus provides a practical solution for the deployment and application of engineered cellular systems.
dMARCH8,aDrosophilaubiquitin E3 ligase, regulates polymodifications of tubulin in the spermiogenic pathway
Authors: Gosavi Ujwala A. S. , Chatterjee Nabanita , Nyachhyon Utsav , Pearce Brian R , Harvey Robert J , Bazinet Christopher
Published: February 2017

Ciliary stability and function are regulated by the covalent addition of polyglutamate and polyglycine chains to axonemal tubulin subunits. TheDrosophilagene CG13442 encodes a predicted ubiquitin E3 ligase involved in the regulation of tubulin glycylation and glutamylation. Homologous to mammalian MARCH8, CG13442/dMARCH8is required for male fertility. Sperm indMARCH8mutant testes appear to undergo a normal individualization process but fail to be transferred to the seminal vesicle. This phenotype is very similar to that of mutants in theNtlgene, shown here to be a glycine transporter using a [3H]glycine uptake assay. Mutations indMARCH8are associated with a reduction of both polyglutamylation and polyglycylation of sperm tubulin. Polyglutamylation of tubulin is significantly increased in theNtl−background, and recovers to wild-type levels in theNtl−-dMARCH8−double mutant background, indicating that glycine and glutamate compete for some common site(s) on tubulin molecules in this system. By analogy to the regulation of the mammalian glycine transporter GlyT2 through ubiquitin-mediated trafficking between the plasma membrane and endosome,dMARCH8may targetNtland glutamate transporters, or other upstream regulators of these proteins.
International environmental NGOs and the politics of genetically modified organisms
Authors: Reis Yuna , Guedes Ana Lucia
Published: February 2017

Purpose

The purpose of the paper is to problematize the resistance role played by international environmental non-governmental organizations (IENGOs) in the governance debate over genetically modified organisms (GMOs) to sustain that some of them are important actors in global environmental governance due to their resistance to transnational corporations.

Design/methodology/approach

The paper presents a reflection on the literature review focused on civil society and IENGOs. Accordingly, the political role of IENGOs in GMO governance is highlighted grounded on the negotiation process of the Cartagena Protocol. At the end, the authors stress that some IENGOs act as resistance actors to corporations’ practices.

Findings

The investigation of the political role played by the IENGOs in the negotiation process of the Cartagena Protocol highlighted that these actors use information to influence decision-makers and power holders, often providing know-how and material resources to local activists and social movement organizations at the domestic level. As a result, the political role played by IENGOs in GMO governance places these international actors as highly influential on the international business (IB) domain.

Originality/value

This paper highlights the importance of IENGOs as resistant actors in what regards corporations’ practices. The authors also sustain that the relationships between states, corporations and civil society actors at the governance level should be part of IB’s research agenda to advance the understanding of how civil society mobilizes, articulates and produces consent and coercion in the international domain. Therefore, the paper contributes to foster actors and voices from the margins as a relevant IB research topic.
Generation Y’s positive and negative eWOM: use of social media and mobile technology
Authors: Zhang Tingting (Christina) , Abound Omran Behzad , Cobanoglu Cihan
Published: February 2017

Purpose

This paper aims to explore the factors that influence Generation Y’s positive or negative electronic word-of-mouth (eWOM) behavior via social media and mobile technology in the foodservice sector. Three types of dining experiences were examined: positive and negative customer experiences and negative customer service followed by a satisfactory recovery package.

Design/methodology/approach

A survey was adopted to test the factors posited to influence Generation Y consumers in these service contexts. Participants were recruited through Amazon Mechanical Turk , and multi-group structural equation modeling was performed to analyze the data.

Findings

Active use of social media and peer influence had a sweeping influence on Generation Y’s intentions to engage in eWOM about their service experiences. Technological sophistication with mobile technology influenced Generation Y to spread positive or negative service experiences, rather than satisfactory recovery experiences. Family influence had a mixed influence on Generation Y subgroups (21-24 years old vs 25-35 years old) to engage in eWOM about their satisfactory or poor service experiences. In satisfactory recovery experiences, family influence showed no significant influence on Generation Y’s eWOM behaviors.

Research limitations/implications

This study enriches online reviews and eWOM marketing theories, adds to service failure and recovery literature and enhances understanding of consumer behavior expressed by Generation Y through the empirical investigation of Generation Y consumers’ behavioral motivations to engage in eWOM through social media and mobile technology.

Practical implications

Engaging Generation Y consumers with social media campaigns and mobile technology development is not merely sufficient in eWOM marketing strategies. Instead, it is essential to create integrative peer communities to motivate Generation Y consumers to engage in eWOM marketing. Marketers need to pay attention to the mixed effects of family influences on the eWOM behaviors of subgroups of Generation Y in positive or negative service experiences.

Originality/value

Given the scarcity of consumer behavior research into Generation Y as an emerging market segment, this paper makes an incremental contribution by developing and validating a model of factors that influence Generation Y consumers’ eWOM intentions through social networking and mobile technologies in three major service contexts: positive, negative and recovery following a service failure.
Roles of negative emotions in customers’ perceived helpfulness of hotel reviews on a user-generated review website
Authors: Lee Minwoo , Jeong Miyoung , Lee Jongseo
Published: February 2017

Purpose

This paper aims to explore how emotional expressions embedded in online hotel reviews influence consumers’ helpfulness perceptions. In particular, this study develops and tests hypotheses analyzing empirical data with a text-mining method in the context of hotels to investigate how review valence influences the perceived helpfulness of online hotel reviews and to examine the role of negative emotional expressions embedded in online consumer reviews with respect to perceived helpfulness.

Design/methodology/approach

This study collected 520,668 online reviews involving 488 hotels in New York City (NYC) on Tripadvisor.com. Of these reviews, 69,202 reviews (13.29 per cent) that had received helpfulness votes were analyzed by a text mining method and negative binomial regression.

Findings

This study demonstrates that negative reviews are considered more helpful than positive reviews when potential customers read online hotel reviews for their future stay. However, when intensively negative emotions were expressed, the degree of helpfulness regarding negative reviews was diminished.

Originality/value

While emotional expressions prevail in online consumer reviews, surprisingly little attention has been devoted to the consequences of emotional expressions in consumers’ information processing and decision-making. Due to the nature of service, given the inseparability of production and consumption, which often hinders the execution of flawless service, consumers tend to be more dependent on reviews to minimize any potential failures they may encounter later on. Therefore, this study fills a gap by demonstrating that negative reviews and emotional expressions play a more crucial role in consumers’ information processing and decision-making.
Flexible working arrangements and strategic positions in SMEs
Authors: Kotey Bernice Adei
Published: February 2017

Purpose

Under the Australian Fair Work Act 2009, employees can request flexible working arrangements (FWAs) from their employers. Provision of FWAs is costly to small and medium enterprises (SMEs). They can, however, use FWAs to achieve competitive advantage. The purpose of this paper is to investigate strategic positions associated with FWA availability in SMEs. It also examines the effects of size and industry sector on FWA availability in SMEs.

Design/methodology/approach

With a sample of 1,541 cases comprising micro, small and medium firms from the Australian Bureau of Statistics’ Business Longitudinal Database, binary regression models were used to analyse the relationships between FWAs and the independent variables: strategic position, firm-size and industry of operation.

Findings

Flexible working hours, flexible leave arrangements and roster/shift selection were used by SMEs pursuing a strategy focussed on human resources. In contrast, a strategic focus on cost correlated negatively with paid parental leave and flexible rosters/shifts. SMEs pursuing innovation were unlikely to provide flexible leave while job sharing was less visible in SMEs focussing on quality. An industry effect was evident with working from home unlikely for firms in industry sectors where employees had to be present at work. Micro- and small-sized firms were less likely than medium firms to provide FWA to their employees.

Originality/value

SMEs with competitive positions based on human capital could use FWAs to attract the required skills. Employees in SMEs that compete on cost may benefit from FWAs in the form of temporary and casual positions.
Relative Width and Height of Handwritten Letter
Authors: Lizega Rika Joseba
Published: February 2017

This is an exploratory study that analyzes the width and the height of letters in two texts written by each of the 21 writers analyzed. After detrending the linear, text, and allograph trends, we proceeded to comparing the sizes obtained in different texts. The different detrended series were compared by means of correlation and t‐test. According to the results regarding the width of letters, the texts of 19 of 21 writers correlated strongly, whereas the texts of two writers did not correlate with the limits of the threshold. With regard to the height of letters, texts written by between 18 and 21 writers of 21 writers correlated strongly, whereas texts that did not correlate were within the threshold value. Regarding both the width and the height of letters, of 21 writers, texts written by between 19 and 21 individuals were found to correlate strongly.
Is the Public Corporation Really in Eclipse? Evidence from the Asia‐Pacific
Authors: Karolyi G. Andrew , Kim Dawoon
Published: February 2017

While the US has experienced a 50% decline in the number of publicly listed corporations since the late 1990s, there has been an 800% increase in the Asia‐Pacific region. Notwithstanding these divergent paths, there are strikingly similar patterns in both regions in the evolution of corporate financial policies. Asia‐Pacific firms invest more in R&D and less in capital expenditures, as do US firms. They have higher cash holdings as a fraction of total assets. Dividends as a fraction of income are lower, the ranks of dividend‐paying firms in the Asia‐Pacific are declining, and, as in the US, share repurchase activity has grown. Concentration ratios of assets, income, cash, and dividends among US firms have risen to the already high levels seen in Asia‐Pacific markets. Changes in corporate financial policies that appear to reveal poorer incentives to invest cannot explain the dramatically different shifts in the landscape for public companies in the US and the Asia‐Pacific region.
VEGF165 induces differentiation of hair follicle stem cells into endothelial cells and plays a role in in vivo angiogenesis
Authors: Quan Renfu , Du Weibin , Zheng Xuan , Xu Shichao , Li Qiang , Ji Xing , Wu Ximei , Shao Rongxue , Yang Disheng
Published: February 2017

Within the vascular endothelial growth factor (VEGF) family of five subtypes, VEGF165 secreted by endothelial cells has been identified to be the most active and widely distributed factor that plays a vital role in courses of angiogenesis, vascularization and mesenchymal cell differentiation. Hair follicle stem cells (HFSCs) can be harvested from the bulge region of the outer root sheath of the hair follicle and are adult stem cells that have multi‐directional differentiation potential. Although the research on differentiation of stem cells (such as fat stem cells and bone marrow mesenchymal stem cells) to the endothelial cells has been extensive, but the various mechanisms and functional forms are unclear. In particular, study on HFSCs’ directional differentiation into vascular endothelial cells using VEGF165 has not been reported. In this study, VEGF165 was used as induction factor to induce the differentiation from HFSCs into vascular endothelial cells, and the results showed that Notch signalling pathway might affect the differentiation efficiency of vascular endothelial cells. In addition, the in vivo transplantation experiment provided that HFSCs could promote angiogenesis, and the main function is to accelerate host‐derived neovascularization. Therefore, HFSCs could be considered as an ideal cell source for vascular tissue engineering and cell transplantation in the treatment of ischaemic diseases.
Mesenchymal stem cell‐loaded cardiac patch promotes epicardial activation and repair of the infarcted myocardium
Authors: Wang Qiang‐li , Wang Hai‐jie , Li Zhi‐hua , Wang Yong‐li , Wu Xue‐ping , Tan Yu‐zhen
Published: February 2017

Cardiac patch is considered a promising strategy for enhancing stem cell therapy of myocardial infarction (MI). However, the underlying mechanisms for cardiac patch repairing infarcted myocardium remain unclear. In this study, we investigated the mechanisms of PCL/gelatin patch loaded with MSCs on activating endogenous cardiac repair. PCL/gelatin patch was fabricated by electrospun. The patch enhanced the survival of the seeded MSCs and their HIF‐1α, Tβ4, VEGF and SDF‐1 expression and decreased CXCL14 expression in hypoxic and serum‐deprived conditions. In murine MI models, the survival and distribution of the engrafted MSCs and the activation of the epicardium were examined, respectively. At 4 weeks after transplantation of the cell patch, the cardiac functions were significantly improved. The engrafted MSCs migrated across the epicardium and into the myocardium. Tendency of HIF‐1α, Tβ4, VEGF, SDF‐1 and CXCL14 expression in the infarcted myocardium was similar with expression in vitro. The epicardium was activated and epicardial‐derived cells (EPDCs) migrated into deep tissue. The EPDCs differentiated into endothelial cells and smooth muscle cells, and some of EPDCs showed to have differentiated into cardiomyocytes. Density of blood and lymphatic capillaries increased significantly. More c‐kit+ cells were recruited into the infarcted myocardium after transplantation of the cell patch. The results suggest that epicardial transplantation of the cell patch promotes repair of the infarcted myocardium and improves cardiac functions by enhancing the survival of the transplanted cells, accelerating locality paracrine, and then activating the epicardium and recruiting endogenous c‐kit+ cells. Epicardial transplantation of the cell patch may be applied as a novel effective MI therapy.
Using eHealth strategies in delivering dietary and other therapies in patients with irritable bowel syndrome and inflammatory bowel disease
Authors: Ankersen Dorit Vedel , Carlsen Katrine , Marker Dorte , Munkholm Pia , Burisch Johan
Published: February 2017

Health‐care systems around the world are facing increasing costs. Non‐adherent, chronically ill patients are one such expense incurred by health‐care providers. Web‐based home‐monitoring of patients—or eHealth—has been shown to increase adherence to medical therapy, facilitate contact between patients and health‐care professionals, and reduce time to remission for patients with inflammatory bowel disease (IBD). Web‐based treatment is a supportive tool for the health‐care provider in an out‐patient clinic. eHealth web‐programs, such as the Constant Care application, visualize disease activity in a traffic light system and empower patients to screen for disease activity, enabling them to respond appropriately to their symptoms. The eHealth screening procedure for monitoring both pediatric and adult IBD patients is based on a self‐obtained symptom score, together with a fecal biomarker for inflammation (fecal calprotectin) that the patients can measure independently using their smart phone, providing both patient and physician with an immediate disease status that they can react to instantaneously. Likewise, web applications for IBD patients, web applications for irritable bowel syndrome (IBS) patients and also IBD patients with co‐existing IBS, have proven valuable for monitoring and treating IBS symptoms with a diet low in fermentable oligo‐, di‐, monosaccharides and polyols (low‐FODMAP diet). With careful disease monitoring via the web application and increased patient adherence, eHealth might be capable of improving the natural disease course of IBD and IBS.
Explaining Export Performance through Inputs: Evidence from Aggregated Cross‐country Firm‐level Data
Authors: van der Marel Erik
Published: February 2017

Which trade barrier related to intermediate inputs forms a greater burden on the export performance of firms in developing countries? Using aggregated cross‐country firm‐level data covering 43 mostly developing economies, this paper estimates the marginal importance of the impact of various intermediate input trade cost barriers, namely tariffs, non‐tariff barriers (NTBs) and services barriers, on firms' export behavior. In a cross‐sectoral setting, this paper takes the firm's export performance in goods as a central focus to study the effects of these different trade barriers through the exporting firm's choice of use of intermediate inputs. The results show that the most significant trade barriers on inputs that impede export performance in developing countries are mainly NTBs and restrictions of services.
Use of TrueBeam developer mode for imaging QA
Authors: Valdes Gilmer , Morin Olivier , Valenciaga Yanisley , Kirby Niel , Pouliot Jean , Chuang Cynthia
Published: February 2017

The purpose of this study was to automate regular Imaging QA procedures to become more efficient and accurate. Daily and monthly imaging QA for SRS and SBRT protocols were fully automated on a Varian linac. A three‐step paradigm where the data are automatically acquired, processed, and analyzed was defined. XML scripts were written and used in developer mode in a TrueBeam linac to automatically acquire data. MATLAB R013B was used to develop an interface that could allow the data to be processed and analyzed. Hardware was developed that allowed the localization of several phantoms simultaneously on the couch. 14 KV CBCTs from the Emma phantom were obtained using a TrueBeam onboard imager as example of data acquisition and analysis. The images were acquired during two months. Artifacts were artificially introduced in the images during the reconstruction process using iTool reconstructor. Support vector machine algorithms to automatically identify each artifact were written using the Machine Learning MATLAB R2011 Toolbox. A daily imaging QA test could be performed by an experienced medical physicist in min. The same test, if automated using our paradigm, could be performed in min. In the same manner, a monthly imaging QA could be performed by a physicist in min and, if fully automated, in min. Additionally, quantitative data analysis could be automatically performed by Machine Learning Algorithms that could remove the subjectivity of data interpretation in the QA process. For instance, support vector machine algorithms could correctly identify beam hardening, rings and scatter artifacts. Traditional metrics, as well as metrics that describe texture, are needed for the classification. Modern linear accelerators are equipped with advanced 2D and 3D imaging capabilities that are used for patient alignment, substantially improving IGRT treatment accuracy. However, this extra complexity exponentially increases the number of QA tests needed. Using the new paradigm described above, not only the bare minimum — but also best practice — QA programs could be implemented with the same manpower.

PACS number: 87, 87.10.‐e
Evaluation of the MIM Symphony treatment planning system for low‐dose‐rate‐ prostate brachytherapy
Authors: Dhanesar Sandeep K. , Lim Tze Y. , Du Weiliang , Bruno Teresa L. , Frank Steven J. , Kudchadker Rajat J.
Published: February 2017

MIM Symphony is a recently introduced low‐dose‐rate prostate brachytherapy treatment planning system (TPS). We evaluated the dosimetric and planning accuracy of this new TPS compared to the universally used VariSeed TPS. For dosimetric evaluation of the MIM Symphony version 5.4 TPS, we compared dose calculations from the MIM Symphony TPS with the formalism recommended by the American Association of Physicists in Medicine Task Group 43 report (TG‐43) and those generated by the VariSeed version 8.0 TPS for iodine‐125 (I‐125; Models 6711 and IAI‐125A), palladium‐103 (Pd‐103; Model 200), and cesium‐131 (Cs‐131; Model Cs‐1). Validation was performed for both line source and point source approximations. As part of the treatment planning validation, first a QA phantom (CIRS Brachytherapy QA Phantom Model 045 SN#D7210‐3) containing three ellipsoid objects with certified volumes was scanned in order to check the volume accuracy of the contoured structures in MIM Symphony. Then the DICOM data containing 100 patient plans from the VariSeed TPS were imported into the MIM Symphony TPS. The 100 plans included 25 each of I‐125 pre‐implant plans, Pd‐103 pre‐implant plans, I‐125 Day 30 plans (i.e., from 1 month after implantation), and Pd‐103 Day 30 plans. The dosimetric parameters (including prostate volume, prostate D90 values, and rectum V100 values) of the 100 plans were calculated independently on the two TPSs. Other TPS tests that were done included verification of source input and geometrical accuracy, data transfer between different planning systems, text printout, 2D dose plots, DVH printout, and template grid accuracy. According to the line source formalism, the dosimetric results between the MIM Symphony TPS and TG‐43 were within 0.5% (0.02 Gy) for . In the line source approximation validation, MIM Symphony TPS values agreed with VariSeed TPS values to within 0.5% (0.09 Gy) for . Similarly, in point source approximation validation, the MIM Symphony values agreed to within 1% of the TG‐43 and VariSeed values for . The volume calculations obtained from the MIM Symphony TPS for the CIRS Brachytherapy QA Phantom were within 1% of the actual volume of the phantom. For the clinical cases, the volume and dosimetric parameter calculations for the prostate and rectum did not differ substantially between the pre‐implant and Day 30 plans. Overall, our investigations showed negligible differences in dosimetry calculations and planning parameters between the two TPSs. The tests done to check the performance of the MIM Symphony TPS, such as the library data, data transfer, isodose and DVH printout, were found to be satisfactory. On the basis of these results, we conclude that the MIM Symphony TPS can be used as an alternative to the VariSeed TPS for low‐dose‐rate prostate brachytherapy.

PACS numbers: 87.53.Jw; 87.55.D‐, 87.55.Qr
Using lesion washout volume fraction as a biomarker to improve suspicious breast lesion characterization
Authors: Huang Jie , Schafer Sarah M. , Aben Gerald R. , Hoisington Lori A.
Published: February 2017

The purpose of this study was to evaluate using lesion washout (WO) volume fraction as a biomarker to improve the characterization of suspicious breast lesions. Study lesions consisted of a total of 60 malignant tumors (BI‐RADS 6) and 62 suspicious lesions (BI‐RADS 4 or 5). The biopsies of these suspicious lesions resulted in a total of 30 malignant tumors and 32 benign lesions, respectively, yielding a 48.4% positive predictive value (PPV) of the biopsies. The mean and standard deviation of the lesion WO volume fraction of these 60 BI‐RADS 6 malignant tumors were first computed to establish a 99% sensitivity threshold value for malignant tumors, and then the biomarker was used to characterize the suspicious lesions. Using the biomarker would characterize all the malignant tumors as malignant, 12 out of the 32 benign lesions as benign, potentially resulting in a 24% improvement rate in the PPV of the biopsies (from 48.4% to 60%) and consequently a 22.5% reduction rate in the false‐positive rate of benign biopsies (from 51.6% to 40%). The lesion WO volume fraction biomarker could improve the computer‐based assessment of breast MRI by increasing the PPV of breast biopsies and reducing the number of unnecessary biopsies without compromising sensitivity.

PACS number: 87.61.Tg, 87.19.Xj
Use of diverging apertures to minimize the edge scatter in passive scattering proton therapy
Authors: Zhao Tianyu , Cai Bin , Sun Baozhou , Grantham Kevin , Mutic Sasa , Klein Eric
Published: February 2017

The purpose of this study was to evaluate the use of diverging‐cut aperture to minimize collimator contamination in proton therapy. Two sets of apertures with nondivergent and divergent edge were fabricated to produce a field at the radiation isocenter of a single‐room proton therapy unit. Transverse profiles were acquired in a scanning water tank with both aperture sets. Up to 9.5% extra dose was observed from aperture scattering near the field edges with the nondivergent aperture set at 2 cm above the water surface and remained 3.0% at depth of 10 cm. For the divergent set, the contamination was reduced to less than 3.5% and 1.3%, respectively. Our study demonstrated that scattering from apertures contaminated the dose distribution near the field edge at shallow depth. A diverging‐cut aperture was capable of reducing the contamination and is recommended for use in passive scattering proton therapy, especially when critical organs are lateral and proximal to the target at shallow depth.

PACS numbers: 87.55.ne, 87.56.nk
Noncoplanar verification: a feasibility study using Philips' Pinnacle3 treatment planning system
Authors: Yohannes Indra , Prasetio Heru , Bert Christoph
Published: February 2017

Noncoplanar fields are normally used to improve the dose conformity of the target while sparing organs at risk. One of the methods to verify the dose distribution from the noncoplanar fields is by comparing their planar dose distributions from the treatment planning system (TPS) and the measured ones; for example, using film or electronic portal imaging devices (EPID). The planar dose distributions of the measurement tools, that are normally perpendicular to the central axis of the beam, can be calculated by creating special structures to mimic them in the TPS. With TPS commercially available today, however, it is not easy to create these special structures, especially in the noncoplanar configuration. For this work, we have written in‐house scripts in the Pinnacle3 TPS that can create the structures and define them as virtual planes. These virtual planes can be generated for any arbitrary gantry and couch angles, as well as source to planar distance, so that the planar dose maps at these planes can be computed. Two independent quality assurance (QA) tools were used to validate the planar dose distributions computed using the scripts for three open fields and one IMRT field at several different couch angles. The absolute planar dose patterns measured by the QA tools for all fields at all couch angles were found to be in good agreement, more than 95% (gamma criteria 3% delta dose and 3 mm distance to agreement), with the calculated ones by TPS. The results of this feasibility study can be valuable either for pretreatment dose verification or for in vivo dosimetry that directly implements the planar dose distributions from the TPS, particularly for the noncoplanar fields.

PACS numbers: 87.55.de, 87.55.Qr, 87.56.Fc
Inter‐ and intrafractional dose uncertainty in hypofractionated Gamma Knife radiosurgery
Authors: Kim Taeho , Sheehan Jason , Schlesinger David
Published: February 2017

The purpose of this study is to evaluate inter‐ and intrafractional dose variations resulting from head position deviations for patients treated with the Extend relocatable frame system utilized in hypofractionated Gamma Knife radiosurgery (GKRS). While previous reports characterized the residual setup and intrafraction uncertainties of the system, the dosimetric consequences have not been investigated. A digital gauge was used to measure the head position of 16 consecutive Extend patients (62 fractions) at the time of simulation, before each fraction, and immediately following each fraction. Vector interfraction (difference between simulation and prefraction positions) and intrafraction (difference between postfraction and prefraction positions) shifts in patient position were calculated. Planned dose distributions were shifted by the offset to determine the time‐of‐treatment dose. Variations in mean and maximum target and organ at risk (OAR) doses as a function of positional shift were evaluated. The mean vector interfraction shift was 0.64 mm (Standard Deviation (SD): 0.25 mm, maximum: 1.17 mm). The mean intrafraction shift was 0.39 mm (SD: 0.25 mm, maximum: 1.44 mm). The mean variation in mean target dose was 0.66% (SD: 1.15%, maximum: 5.77%) for interfraction shifts and 0.26% (SD: 0.34%, maximum: 1.85%) for intrafraction shifts. The mean variation in maximum dose to OARs was 7.15% (SD: 5.73%, maximum: 30.59%) for interfraction shifts and 4.07% (SD: 4.22%, maximum: 17.04%) for intrafraction shifts. Linear fitting of the mean variation in maximum dose to OARs as a function of position yielded dose deviations of 10.58%/mm for interfractional shifts and 7.69%/mm for intrafractional shifts. Positional uncertainties when performing hypofractionated Gamma Knife radiosurgery with the Extend system are small and comparable to frame‐based uncertainties (). However, the steep dose gradient characteristics of GKRS mean that the dosimetric consequences of positional uncertainties should be considered as part of treatment planning. These dose uncertainties should be evaluated in the context of tumor response and OAR tolerance for hypofractionated treatment scenarios where any increase in dose may be tempered by the increased protection hypofractionation provides to normal tissue.

PACS number(s): 87.52.‐g
A novel method for radiotherapy patient identification using surface imaging
Authors: Wiant David B. , Verchick Quinton , Gates Percy , Vanderstraeten Caroline L. , Maurer Jacqueline M. , Hayes T. Lane , Liu Han , Sintay Benjamin J.
Published: February 2017

Performing a procedure on the wrong patient or site is one of the greatest errors that can occur in medicine. The addition of automation has been shown to reduce errors in many processes. In this work we explore the use of an automated patient identification process using optical surface imaging for radiotherapy treatments. Surface imaging uses visible light to align the patient to a reference surface in the treatment room. It is possible to evaluate the similarity between a daily set‐up surface image and the reference image using distance to agreement between the points on the two surfaces. The higher the percentage overlapping points within a defined distance, the more similar the surfaces. This similarity metric was used to intercompare 16 left‐sided breast patients. The reference surface for each patient was compared to 10 daily treatment surfaces for the same patient, and 10 surfaces from each of the other 15 patients (for a total of 160 comparisons per patient), looking at the percent of points overlapping. For each patient, the minimum same‐patient similarity score was higher than the maximum different‐patient score. For the group as a whole a threshold was able to classify correct and incorrect patients with high levels of accuracy. A 10‐fold cross‐validation using linear discriminant analysis gave cross‐validation loss of 0.0074. An automated process using surface imaging is a feasible option to provide nonharmful daily patient identification verification using currently available technology.

PACS number(s): 87.53.Jw, 87.55.N‐, 87.55.Qr, 87.57.N‐, 87.63.L‐
Benchmarking of five commercial deformable image registration algorithms for head and neck patients
Authors: Pukala Jason , Johnson Perry B. , Shah Amish P. , Langen Katja M. , Bova Frank J. , Staton Robert J. , Mañon Rafael R. , Kelly Patrick , Meeks Sanford L.
Published: February 2017

Benchmarking is a process in which standardized tests are used to assess system performance. The data produced in the process are important for comparative purposes, particularly when considering the implementation and quality assurance of DIR algorithms. In this work, five commercial DIR algorithms (MIM, Velocity, RayStation, Pinnacle, and Eclipse) were benchmarked using a set of 10 virtual phantoms. The phantoms were previously developed based on CT data collected from real head and neck patients. Each phantom includes a start of treatment CT dataset, an end of treatment CT dataset, and the ground‐truth deformation vector field (DVF) which links them together. These virtual phantoms were imported into the commercial systems and registered through a deformable process. The resulting DVFs were compared to the ground‐truth DVF to determine the target registration error (TRE) at every voxel within the image set. Real treatment plans were also recalculated on each end of treatment CT dataset and the dose transferred according to both the ground‐truth and test DVFs. Dosimetric changes were assessed, and TRE was correlated with changes in the DVH of individual structures. In the first part of the study, results show mean TRE on the order of 0.5 mm to 3 mm for all phantoms and ROIs. In certain instances, however, misregistrations were encountered which produced mean and max errors up to 6.8 mm and 22 mm, respectively. In the second part of the study, dosimetric error was found to be strongly correlated with TRE in the brainstem, but weakly correlated with TRE in the spinal cord. Several interesting cases were assessed which highlight the interplay between the direction and magnitude of TRE and the dose distribution, including the slope of dosimetric gradients and the distance to critical structures. This information can be used to help clinicians better implement and test their algorithms, and also understand the strengths and weaknesses of a dose adaptive approach.

PACS number(s): 87.57.nj, 87.55.dk, 87.55.Qr
Ocular brachytherapy dosimetry for and in the presence of gold nanoparticles: a Monte Carlo study
Authors: Asadi Somayeh , Vaez‐zadeh Mehdi , Vahidian Mohammad , Marghchouei Mahdieh , Masoudi S. Farhad
Published: February 2017

The aim of the present Monte Carlo study is to evaluate the variation of energy deposition in healthy tissues in the human eye which is irradiated by brachytherapy sources in comparison with the resultant dose increase in the gold nanoparticle (GNP)‐loaded choroidal melanoma. The effects of these nanoparticles on normal tissues are compared between and as two ophthalmic brachytherapy sources. Dose distribution in the tumor and healthy tissues has been taken into account for both brachytherapy sources. Also, in certain points of the eye, the ratio of the absorbed dose by the normal tissue in the presence of GNPs to the absorbed dose by the same point in the absence of GNPs has been calculated. In addition, differences of the absorbed dose in the tumor observed in the comparison of simple water phantom and actual simulated human eye in presence of GNPs are also a matter of interest that have been considered in the present work. The difference between the eye globe and the water phantom is more obvious for than that of the when the ophthalmic dosimetry is done in the presence of GNPs. Whenever these nanoparticles are utilized in enhancing the absorbed dose by the tumor, the use of brachytherapy source will greatly amplify the amount of dose enhancement factor (DEF) in the tumor site without inflicting much damage to healthy organs, when compared to the source. For instance, in the concentration of 30 mg GNPs, the difference amongst the calculated DEF for between these phantoms is 5.3%, while it is 2.45% for . Furthermore, in Monte Carlo studies of eye brachytherapy, more precise definition of the eye phantom instead of a water phantom will become increasingly important when we use as opposed to .

PACS number(s): 87.53.Jw, 87.85.Rs, 87.10.Rt
Experimental validation of a kV source model and dose computation method for CBCT imaging in an anthropomorphic phantom
Authors: Poirier Yannick , Tambasco Mauro
Published: February 2017

We present an experimental validation of a kilovoltage (kV) X‐ray source characterization model in an anthropomorphic phantom to estimate patient‐specific absorbed dose from kV cone‐beam computed tomography (CBCT) imaging procedures and compare these doses to nominal weighted CT‐dose index () dose estimates. We simulated the default Varian on‐board imager 1.4 (OBI) default CBCT imaging protocols (i.e., standard‐dose head, low‐dose thorax, pelvis, and pelvis spotlight) using our previously developed and easy to implement X‐ray point‐source model and source characterization approach. We used this characterized source model to compute absorbed dose in homogeneous and anthropomorphic phantoms using our previously validated in‐house kV dose computation software (kVDoseCalc). We compared these computed absorbed doses to doses derived from ionization chamber measurements acquired at several points in a homogeneous cylindrical phantom and from thermoluminescent detectors (TLDs) placed in the anthropomorphic phantom. In the homogeneous cylindrical phantom, computed values of absorbed dose relative to the center of the phantom agreed with measured values within of local dose, except in regions of high‐dose gradient where the distance to agreement (DTA) was 2 mm. The computed absorbed dose in the anthropomorphic phantom generally agreed with TLD measurements, with an average percent dose difference ranging from to , depending on the characterized CBCT imaging protocol. The low‐dose thorax and the standard dose scans showed the best and worst agreement, respectively. Our results also broadly agree with published values, which are approximately twice as high as the nominal would suggest. The results demonstrate that our previously developed method for modeling and characterizing a kV X‐ray source could be used to accurately assess patient‐specific absorbed dose from kV CBCT procedures within reasonable accuracy, and serve as further evidence that existing assessments underestimate absorbed dose delivered to patients.

PACS number(s): 87.57.Q‐, 87.57.uq, 87.10.Rt