bluuebunny/crossref_metadata_2025_split huggingface dataset:
On correlations in IMRT planning aims
Authors: Roy Arkajyoti , Das Indra J. , Nohadani Omid 
Published: February 2017

The purpose was to study correlations amongst IMRT DVH evaluation points and how their relaxation impacts the overall plan. 100 head‐and‐neck cancer cases, using the Eclipse treatment planning system with the same protocol, are statistically analyzed for PTV, brainstem, and spinal cord. To measure variations amongst the plans, we use (i) interquartile range (IQR) of volume as a function of dose, (ii) interquartile range of dose as a function of volume, and (iii) dose falloff. To determine correlations for institutional and ICRU goals, conditional probabilities and medians are computed. We observe that most plans exceed the median PTV dose (average prescribed dose). Furthermore, satisfying reduced the probability of also satisfying , constituting a negative correlation of these goals. On the other hand, satisfying increased the probability of satisfying , suggesting a positive correlation. A positive correlation is also observed between the PTV and . Similarly, a positive correlation between the brainstem and is measured by an increase in the conditional median of , when is violated. Despite the imposed institutional and international recommendations, significant variations amongst DVH points can occur. Even though DVH aims are evaluated independently, sizable correlations amongst them are possible, indicating that some goals cannot be satisfied concurrently, calling for unbiased plan criteria.PACS number(s): 87.55.dk, 87.53.Bn, 87.55.Qr, 87.55.de.
Production, review, and impact of technical quality control guidelines in a national context
Authors: Nielsen Michelle K. , Malkoske Kyle E. , Brown Erika , Diamond Kevin , Frenière Normand , Grant John , Pomerleau‐Dalcourt Natalie , Schella Jason , Schreiner L. John , Tantôt Laurent , Villarreal‐Barajas J. Eduardo , Bissonnette Jean‐Pierre 
Published: February 2017

A close partnership between the Canadian Partnership for Quality Radiotherapy (CPQR) and the Canadian Organization of Medical Physicist's (COMP) Quality Assurance and Radiation Safety Advisory Committee (QARSAC) has resulted in the development of a suite of Technical Quality Control (TQC) guidelines for radiation treatment equipment; they outline specific performance objectives and criteria that equipment should meet in order to assure an acceptable level of radiation treatment quality. The adopted framework for the development and maintenance of the TQCs ensures the guidelines incorporate input from the medical physics community during development, measures the workload required to perform the QC tests outlined in each TQC, and remain relevant (i.e., “living documents”) through subsequent planned reviews and updates. The framework includes consolidation of existing guidelines and/or literature by expert reviewers, structured stages of public review, external field‐testing, and ratification by COMP. This TQC development framework is a cross‐country initiative that allows for rapid development of robust, community‐driven living guideline documents that are owned by the community and reviewed to keep relevant in a rapidly evolving technical environment. Community engagement and uptake survey data shows 70% of Canadian centers are part of this process and that the data in the guideline documents reflect, and are influencing, the way Canadian radiation treatment centers run their technical quality control programs. For a medium‐sized center comprising six linear accelerators and a comprehensive brachytherapy program, we evaluate the physics workload to 1.5 full‐time equivalent physicists per year to complete all QC tests listed in this suite.PACS number(s): 87.55.Qr, 87.56.Fc, 87.56.‐v
Development and evaluation of a clinical model for lung cancer patients using stereotactic body radiotherapy (SBRT) within a knowledge‐based algorithm for treatment planning
Authors: Chin Snyder Karen , Kim Jinkoo , Reding Anne , Fraser Corey , Gordon James , Ajlouni Munther , Movsas Benjamin , Chetty Indrin J. 
Published: February 2017

The purpose of this study was to describe the development of a clinical model for lung cancer patients treated with stereotactic body radiotherapy (SBRT) within a knowledge‐based algorithm for treatment planning, and to evaluate the model performance and applicability to different planning techniques, tumor locations, and beam arrangements. 105 SBRT plans for lung cancer patients previously treated at our institution were included in the development of the knowledge‐based model (KBM). The KBM was trained with a combination of IMRT, VMAT, and 3D CRT techniques. Model performance was validated with 25 cases, for both IMRT and VMAT. The full KBM encompassed lesions located centrally vs. peripherally (43:62), upper vs. lower (62:43), and anterior vs. posterior (60:45). Four separate sub‐KBMs were created based on tumor location. Results were compared with the full KBM to evaluate its robustness. Beam templates were used in conjunction with the optimizer to evaluate the model's ability to handle suboptimal beam placements. Dose differences to organs‐at‐risk (OAR) were evaluated between the plans generated by each KBM. Knowledge‐based plans (KBPs) were comparable to clinical plans with respect to target conformity and OAR doses. The KBPs resulted in a lower maximum spinal cord dose by compared to clinical plans, Sub‐KBMs split according to tumor location did not produce significantly better DVH estimates compared to the full KBM. For central lesions, compared to the full KBM, the peripheral sub‐KBM resulted in lower dose to 0.035 cc and 5 cc of the esophagus, both by , For all lesions, compared to the full KBM, the posterior sub‐KBM resulted in higher dose to 0.035 cc, 0.35 cc, and 1.2 cc of the spinal cord by , Plans using template beam arrangements met target and OAR criteria, with an increase noted in maximum heart dose (, ) and GI (, ) for the nine‐field plans relative to KBPs planned with custom beam angles. A knowledge‐based model for lung SBRT consisting of multiple treatment modalities and lesion locations produced comparable plan quality to clinical plans. With proper training and validation, a robust KBM can be created that encompasses both IMRT and VMAT techniques, as well as different lesion locations.PACS number(s): 87.55de, 87.55kh, 87.53Ly
Experimental evaluation of a GPU‐based Monte Carlo dose calculation algorithm in the Monaco treatment planning system
Authors: Paudel Moti R. , Kim Anthony , Sarfehnia Arman , Ahmad Sayed B. , Beachey David J. , Sahgal Arjun , Keller Brian M. 
Published: February 2017

A new GPU‐based Monte Carlo dose calculation algorithm (GPUMCD), developed by the vendor Elekta for the Monaco treatment planning system (TPS), is capable of modeling dose for both a standard linear accelerator and an Elekta MRI linear accelerator. We have experimentally evaluated this algorithm for a standard Elekta Agility linear accelerator. A beam model was developed in the Monaco TPS (research version 5.09.06) using the commissioned beam data for a 6 MV Agility linac. A heterogeneous phantom representing several scenarios — tumor‐in‐lung, lung, and bone‐in‐tissue — was designed and built. Dose calculations in Monaco were done using both the current clinical Monte Carlo algorithm, XVMC, and the new GPUMCD algorithm. Dose calculations in a Pinnacle TPS were also produced using the collapsed cone convolution (CCC) algorithm with heterogeneity correction. Calculations were compared with the measured doses using an ionization chamber (A1SL) and Gafchromic EBT3 films for , and field sizes. The percentage depth doses (PDDs) calculated by XVMC and GPUMCD in a homogeneous solid water phantom were within of film measurements and within 1% of ion chamber measurements. For the tumor‐in‐lung phantom, the calculated doses were within of film measurements for GPUMCD. For the lung phantom, doses calculated by all of the algorithms were within of film measurements, except for the field size where the CCC algorithm underestimated the depth dose by in a larger extent of the lung region. For the bone phantom, all of the algorithms were equivalent and calculated dose to within of film measurements, except at the interfaces. Both GPUMCD and XVMC showed interface effects, which were more pronounced for GPUMCD and were comparable to film measurements, whereas the CCC algorithm showed these effects poorly.PACS number(s): 87.53.Bn, 87.55.dh, 87.55.km
Difference in performance between 3D and 4D CBCT for lung imaging: a dose and image quality analysis
Authors: Thengumpallil Sheeba , Smith Kathleen , Monnin Pascal , Bourhis Jean , Bochud François , Moeckli Raphaël 
Published: February 2017

The study was to describe and to compare the performance of 3D and 4D CBCT imaging modalities by measuring and analyzing the delivered dose and the image quality. The 3D (Chest) and 4D (Symmetry) CBCT Elekta XVI lung IGRT protocols were analyzed. Dose profiles were measured with TLDs inside a dedicated phantom. The dosimetric indicator cone‐beam dose index (CBDI) was evaluated. The image quality analysis was performed by assessing the contrast transfer function (CTF), the noise power spectrum (NPS) and the noise‐equivalent quanta (NEQ). Artifacts were also evaluated by simulating irregular breathing variations. The two imaging modalities showed different dose distributions within the phantom. At the center, the 3D CBCT delivered twice the dose of the 4D CBCT. The CTF was strongly reduced by motion compared to static conditions, resulting in a CTF reduction of 85% for the 3D CBCT and 65% for the 4D CBCT. The amplitude of the NPS was two times higher for the 4D CBCT than for the 3D CBCT. In the presence of motion, the NEQ of the 4D CBCT was 50% higher than the 3D CBCT. In the presence of breathing irregularities, the 4D CBCT protocol was mainly affected by view‐aliasing artifacts, which were typically cone‐beam artifacts, while the 3D CBCT protocol was mainly affected by duplication artifacts. The results showed that the 4D CBCT ensures a reasonable dose and better image quality when moving targets are involved compared to 3D CBCT. Therefore, 4D CBCT is a reliable imaging modality for lung free‐breathing radiation therapy.PACS number(s): 87.57.C‐, 87.57.uq, 87.53.Ly
In Vitro
Activity of Bedaquiline against Nontuberculous Mycobacteria in China
Authors: Pang Yu , Zheng Huiwen , Tan Yaoju , Song Yuanyuan , Zhao Yanlin 
Published: February 2017

ABSTRACT

The main goal of our study was to evaluate the
in vitro
bedaquiline susceptibility of six prevalent species of pathogenic nontuberculous mycobacteria (NTM) in China. In addition, we investigated the potential molecular mechanisms contributing to bedaquiline resistance in the different NTM species. Among slowly growing mycobacteria (SGM), bedaquiline exhibited the highest activity against
Mycobacterium avium
; the MIC
50
and MIC
90
values were 0.03 and 16 mg/liter, respectively. Among rapidly growing mycobacteria (RGM),
Mycobacterium abscessus
subsp.
abscessus
(
M. abscessu
s) and
Mycobacterium abscessus
subsp.
massiliense
(
M. massiliense
) seemed more susceptible to bedaquiline than
Mycobacterium fortuitum
, with MIC
50
and MIC
90
values of 0.13 and >16 mg/liter, respectively, for both species. On the basis of bimodal distributions of bedaquiline MICs, we proposed the following epidemiological cutoff (ECOFF) values: 1.0 mg/liter for SGM and 2.0 mg/liter for RGM. Among
M. avium
,
Mycobacterium intracellulare
,
Mycobacterium kansasii
,
M. abscessus
,
M. massiliense
, and
M. fortuitum
isolates, 14 (29.8%), 41 (27.2%), 33 (39.3%), 44 (20.2%), 42 (25.8%), and 7 (31.8%), respectively, were resistant to bedaquiline. No significant differences in the proportions of bedaquiline resistance among these species were observed (
P
> 0.05). Genetic mutations were observed in 74 isolates (10.8%), with all nucleotide substitutions being synonymous. In conclusion, our data demonstrate that bedaquiline shows moderate
in vitro
activity against NTM species. Using the proposed ECOFF values, we could distinguish between bedaquiline-resistant and -susceptible strains with the broth dilution method. In addition, no nonsynonymous mutations in the
atpE
gene that conferred bedaquiline resistance in all six NTM species were identified.
Integron-Associated DfrB4, a Previously Uncharacterized Member of the Trimethoprim-Resistant Dihydrofolate Reductase B Family, Is a Clinically Identified Emergent Source of Antibiotic Resistance
Authors: Toulouse Jacynthe L. , Edens Thaddeus J. , Alejaldre Lorea , Manges Amee R. , Pelletier Joelle N. 
Published: February 2017

ABSTRACT

Whole-genome sequencing of trimethoprim-resistant
Escherichia coli
clinical isolates identified a member of the trimethoprim-resistant type II dihydrofolate reductase gene family (
dfrB
). The
dfrB4
gene was located within a class I integron flanked by multiple resistance genes. This arrangement was previously reported in a 130.6-kb multiresistance plasmid. The DfrB4 protein conferred a >2,000-fold increased trimethoprim resistance on overexpression in
E. coli
. Our results are consistent with the finding that
dfrB4
contributes to clinical trimethoprim resistance.
Enterococcus faecalis Uses a Phosphotransferase System Permease and a Host Colonization-Related ABC Transporter for Maltodextrin Uptake
Authors: Sauvageot Nicolas , Mokhtari Abdelhamid , Joyet Philippe , Budin-Verneuil Aurélie , Blancato Víctor S. , Repizo Guillermo D. , Henry Céline , Pikis Andreas , Thompson John , Magni Christian , Hartke Axel , Deutscher Josef 
Published: February 2017

ABSTRACT

Maltodextrin is a mixture of maltooligosaccharides, which are produced by the degradation of starch or glycogen. They are mostly composed of α-1,4- and some α-1,6-linked glucose residues. Genes presumed to code for the
Enterococcus faecalis
maltodextrin transporter were induced during enterococcal infection. We therefore carried out a detailed study of maltodextrin transport in this organism. Depending on their length (3 to 7 glucose residues),
E. faecalis
takes up maltodextrins either via MalT, a maltose-specific permease of the phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS), or the ATP binding cassette (ABC) transporter MdxEFG-MsmX. Maltotriose, the smallest maltodextrin, is primarily transported by the PTS permease. A
malT
mutant therefore exhibits significantly reduced growth on maltose and maltotriose. The residual uptake of the trisaccharide is catalyzed by the ABC transporter, because a
malT mdxF
double mutant no longer grows on maltotriose. The trisaccharide arrives as maltotriose-6″-P in the cell. MapP, which dephosphorylates maltose-6′-P, also releases P
i
from maltotriose-6″-P. Maltotetraose and longer maltodextrins are mainly (or exclusively) taken up via the ABC transporter, because inactivation of the membrane protein MdxF prevents growth on maltotetraose and longer maltodextrins up to at least maltoheptaose.
E. faecalis
also utilizes panose and isopanose, and we show for the first time, to our knowledge, that in contrast to maltotriose, its two isomers are primarily transported via the ABC transporter. We confirm that maltodextrin utilization via MdxEFG-MsmX affects the colonization capacity of
E. faecalis
, because inactivation of
mdxF
significantly reduced enterococcal colonization and/or survival in kidneys and liver of mice after intraperitoneal infection.

IMPORTANCE
Infections by enterococci, which are major health care-associated pathogens, are difficult to treat due to their increasing resistance to clinically relevant antibiotics, and new strategies are urgently needed. A largely unexplored aspect is how these pathogens proliferate and which substrates they use in order to grow inside infected hosts. The use of maltodextrins as a source of carbon and energy was studied in
Enterococcus faecalis
and linked to its virulence. Our results demonstrate that
E. faecalis
can efficiently use glycogen degradation products. We show here that depending on the length of the maltodextrins, one of two different transporters is used: the maltose-PTS transporter MalT, or the MdxEFG-MsmX ABC transporter. MdxEFG-MsmX takes up longer maltodextrins as well as complex molecules, such as panose and isopanose.
American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score: a study protocol for the translation and validation of the Dutch language version
Authors: Van Lieshout Esther M M , De Boer A Siebe , Meuffels Duncan E , Den Hoed P Ted , Van der Vlies Cornelis H , Tuinebreijer Wim E , Verhofstad Michael H J 
Published: February 2017

IntroductionThe American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score is among the most commonly used instruments for measuring the outcome of treatment in patients who sustained a complex ankle or hindfoot injury. It combines a clinician-reported and a patient-reported part. A valid Dutch version of this instrument is currently not available. Such a translated and validated instrument would allow objective comparison across hospitals or between patient groups, and with shown validity and reliability it may become a quality of care indicator in future. The main aims of this study are to translate and culturally adapt the AOFAS Ankle-Hindfoot Score questionnaire into Dutch according to international guidelines, and to evaluate the measurement properties of the AOFAS Ankle-Hindfoot Score-Dutch language version (DLV) in patients with a unilateral ankle or hindfoot fracture.Methods and analysisThe design of the study will be a multicentre prospective observational study (case series) in patients who presented to the emergency department with a unilateral ankle or hindfoot fracture or (fracture) dislocation. A research physician or research assistant will complete the AOFAS Ankle-Hindfoot Score-DLV based on interview for the subjective part and a physical examination for the objective part. In addition, patients will be asked to complete the Foot Function Index (FFI) and the Short Form-36 (SF-36). Descriptive statistics (including floor and ceiling effects), internal consistency, construct validity, reproducibility (ie, test–retest reliability, agreement and smallest detectable change) and responsiveness will be assessed for the AOFAS DLV.Ethics and disseminationThis study has been exempted by the Medical Research Ethics Committee (MREC) Erasmus MC (Rotterdam, the Netherlands). Each participant will provide written consent to participate and remain anonymised during the study. The results of the study are planned to be published in an international, peer-reviewed journal.Trial registration numberNTR5613. pre-result.
Onset seasons and clinical outcomes in patients with Stanford type A acute aortic dissection: an observational retrospective study
Authors: Chen Zhaoran , Huang Bi , Yang Yanmin , Hui Rutai , Lu Haisong , Zhao Zhenhua , Lu Zhinan , Zhang Shu , Fan Xiaohan 
Published: February 2017

ObjectivesTo evaluate the association of onset season with clinical outcome in type A acute aortic dissection (AAD).DesignA single-centre, observational retrospective study.SettingThe study was conducted in Fuwai Hospital, the National Centre for Cardiovascular Disease, Beijing, China.ParticipantsFrom 2008 to 2010, a set of consecutive patients with type A AAD, confirmed by CT scanning, were enrolled and divided into four groups according to onset season: winter (December, January and February), spring (March, April and May), summer (June, July and August) and autumn (September, October and November). The primary end points were in-hospital death and all-cause mortality during follow-up.ResultsOf the 492 cases in this study, 129 occurred in winter (26.2%), 147 in spring (29.9%), 92 in summer (18.7%), and 124 in autumn (25.2%). After a median follow-up of 20.4 months (IQR 9.7–38.9), the in-hospital mortality in cases occurring in autumn was higher than in the other three seasons (23.4% vs 8.4%, p<0.01). Long-term mortality was comparable among the four seasonal groups (p=0.63). After adjustment for age, gender and other risk factors, onset in autumn was still an independent factor associated with increased risk of in-hospital mortality (HR 2.05; 95% CI 1.15 to 3.64, p=0.02) in addition to surgical treatment. Further analysis showed that the seasonal effect on in-hospital mortality (autumn vs other seasons: 57.4% vs 27.3%, p<0.01) was only significant in patients who did not receive surgical treatment. No seasonal effect on long-term clinical outcomes was found in this cohort.ConclusionsOnset in autumn may be a factor that increases the risk of in-hospital death from type A AAD, especially in patients who receive conservative treatment. Immediate surgery improves the short-term and long-term outcomes regardless of onset season.
The name is the message: eagle-stones and materia medica in South America
Authors: Podgorny Irina 
Published: February 2017

Abstract

This chapter presents one case history – the transfer of the name and virtues of ‘eagle-stones’ to Andean minerals and terebratulid brachiopods such as
Clarkeia antisiensis
. Eagle-stones, an ancient remedy of Asian origin, were used in early modern Europe to prevent abortion and as a charm to assist obstetric delivery. In the eighteenth century eagle-stones were the subject of what G. Baronti (
Tra bambini e acque sporche Immersioni nella collezione di amuleti di Giuseppe Bellucci
, Morlacchi, Perugia, 2008) calls the process of folklorization of European learned medicine, becoming a ‘superstition’ and a popular remedy of medical lore. Based on secondary bibliography and documents from the Archivo de Indias in Seville, the paper discusses the uses of eagle-stones in Spain and Spanish America in connection to the texts published, written or translated in the Iberian Peninsula (lapidaries, early modern medical books). The last section proposes clues to analyse the expansion of the trade in eagle-stones to Spanish America, to finally survey the references to ‘eagle-stones’ in Latin American popular medicine of the late nineteenth and early twentieth centuries. Eagle-stones are inscribed not only in the
longue-durée
but also in the intricate networks of commerce.
FDA Approval Summary: Eribulin for Patients with Unresectable or Metastatic Liposarcoma Who Have Received a Prior Anthracycline-Containing Regimen
Authors: Osgood Christy L. , Chuk Meredith K. , Theoret Marc R. , Huang Lan , He Kun , Her Leah , Keegan Patricia , Pazdur Richard 
Published: February 2017

Abstract
On January 28, 2016, the FDA approved eribulin (Halaven; Eisai Inc.) for the treatment of patients with unresectable or metastatic liposarcoma who have received a prior anthracycline-containing regimen. The approval was based on results from a single, randomized, open-label, active-controlled trial (Trial E7389-G000-309) enrolling 452 patients with advanced, locally recurrent or metastatic liposarcoma or leiomyosarcoma. Patients were randomized to eribulin 1.4 mg/m2 intravenously (i.v.) on days 1 and 8 or dacarbazine 850, 1,000, or 1,200 mg/m2 i.v. on day 1 of a 21-day cycle. There was a significant improvement in overall survival [OS; HR, 0.75; 95% confidence interval (CI), 0.61–0.94; P = 0.0119, stratified log-rank] for the overall population. Estimated median OS was 13.5 months (95% CI, 11.1–16.5) in the eribulin arm and 11.3 months (95% CI, 9.5–12.6) in the dacarbazine arm (HR, 0.75; 95% CI, 0.61–0.94; P = 0.011).There were no differences in PFS for the overall population. The effects of eribulin were limited to patients with liposarcoma (n = 143) based on preplanned, exploratory subgroup analyses of OS (HR, 0.51; 95% CI, 0.35–0.75) and progression-free survival (PFS; 0.52; 95% CI, 0.35–0.78). Response rates in both treatment arms were less than 5% in the overall population and in the liposarcoma subgroup. The safety profile was similar to that previously reported for eribulin. The FDA determined that, based on the data reviewed, the benefit–risk assessment for eribulin is positive for patients with advanced, pretreated liposarcoma. Clin Cancer Res; 23(21); 6384–9. ©2017 AACR.