483 research outputs found

    Repeatability of quantitative18F-FLT uptake measurements in solid tumors: an individual patient data multi-center meta-analysis

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    INTRODUCTION: 3'-deoxy-3'-[18F]fluorothymidine (18F-FLT) positron emission tomography (PET) provides a non-invasive method to assess cellular proliferation and response to antitumor therapy. Quantitative18F-FLT uptake metrics are being used for evaluation of proliferative response in investigational setting, however multi-center repeatability needs to be established. The aim of this study was to determine the repeatability of18F-FLT tumor uptake metrics by re-analyzing individual patient data from previously published reports using the same tumor segmentation method and repeatability metrics across cohorts. METHODS: A systematic search in PubMed, EMBASE.com and the Cochrane Library from inception-October 2016 yielded five18F-FLT repeatability cohorts in solid tumors.18F-FLT avid lesions were delineated using a 50% isocontour adapted for local background on test and retest scans. SUVmax, SUVmean, SUVpeak, proliferative volume and total lesion uptake (TLU) were calculated. Repeatability was assessed using the repeatability coefficient (RC = 1.96 × SD of test-retest differences), linear regression analysis, and the intra-class correlation coefficient (ICC). The impact of different lesion selection criteria was also evaluated. RESULTS: Images from four cohorts containing 30 patients with 52 lesions were obtained and analyzed (ten in breast cancer, nine in head and neck squamous cell carcinoma, and 33 in non-small cell lung cancer patients). A good correlation was found between test-retest data for all18F-FLT uptake metrics (R2 ≥ 0.93; ICC ≥ 0.96). Best repeatability was found for SUVpeak(RC: 23.1%), without significant differences in RC between different SUV metrics. Repeatability of proliferative volume (RC: 36.0%) and TLU (RC: 36.4%) was worse than SUV. Lesion selection methods based on SUVmax ≥ 4.0 improved the repeatability of volumetric metrics (RC: 26-28%), but did not affect the repeatability of SUV metrics. CONCLUSIONS: In multi-center studies, differences ≥ 25% in18F-FLT SUV metrics likely represent a true change in tumor uptake. Larger differences are required for FLT metrics comprising volume estimates when no lesion selection criteria are applied

    Patient-reported aesthetic outcomes of upper blepharoplasty:a randomized controlled trial comparing two surgical techniques

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    It is not yet established whether additional orbicularis oculi muscle excision leads to better patient-reported aesthetic outcomes (PRO) compared to a skin-only resection blepharoplasty. A double-blind randomized controlled trial of upper blepharoplasty, with or without muscle excision, was performed on 54 White European patients who assessed the procedure via PRO. FACE-Q questionnaires covering eyes in general, upper eyelids, forehead and eyebrows, overall face, age appearance appraisal, age appraisal, social functioning, satisfaction with the outcome, and adverse effects were completed preoperatively and at 6 and 12 months after upper blepharoplasty. The Patient and Observer Scar Assessment Scale was used to assess scarring. The FACE-Q scores for skin-only and skin/muscle upper blepharoplasty were similar regarding the upper eyelids, forehead and eyebrows, overall face, patient perceived aging and age, social functioning, and satisfaction with the results, and also increased for both procedures with time. The FACE-Q score regarding the eyes in general was higher in the skin-only group at the 12-month follow-up. Scarring and adverse effects did not differ between the groups. Additional muscle resection does not seem to influence patient satisfaction. Thus, when performing an upper blepharoplasty, there is no need for additional muscle resection as a routine procedure to improve patient satisfaction

    ERP mismatch response to phonological and temporal regularities in speech

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    Predictions of our sensory environment facilitate perception across domains. During speech perception, formal and temporal predictions may be made for phonotactic probability and syllable stress patterns, respectively, contributing to the efficient processing of speech input. The current experiment employed a passive EEG oddball paradigm to probe the neurophysiological processes underlying temporal and formal predictions simultaneously. The component of interest, the mismatch negativity (MMN), is considered a marker for experience-dependent change detection, where its timing and amplitude are indicative of the perceptual system's sensitivity to presented stimuli. We hypothesized that more predictable stimuli (i.e. high phonotactic probability and first syllable stress) would facilitate change detection, indexed by shorter peak latencies or greater peak amplitudes of the MMN. This hypothesis was confirmed for phonotactic probability: high phonotactic probability deviants elicited an earlier MMN than low phonotactic probability deviants. We do not observe a significant modulation of the MMN to variations in syllable stress. Our findings confirm that speech perception is shaped by formal and temporal predictability. This paradigm may be useful to investigate the contribution of implicit processing of statistical regularities during (a)typical language development.Maastricht University (Grant to BMJ to support women in higher academic positions) and Netherlands Organization for Scientific Research (NWO) 452-16-004info:eu-repo/semantics/publishedVersio

    Moving targets in space: Movement distance as a predictor for experiences of movement agency

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    Previous research indicates that the experience of agency over one's actions and movements is influenced by movement predictability as well as movement distance (Hon, Seow, & Pereira, 2018). Addressing previous limitations, we present a compelling test of the relation between movement distance and movement agency. Participants in two studies moved targets predictably or unpredictably, and for short, medium, or long distances. Following prior research, distractor cues moved in the opposite direction of the targets. Results showed that movement agency scores were higher for predictable compared to unpredictable movements. Results also consistently showed that when movements were predictable, longer distances by either the target or the distractor cues increased agency relative to shorter distances. Our findings replicate and extend previous findings showing that stimulus movement distances influence judgments of movement agency

    Dentoalveolar traumatology

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    Een patiënt met een dentoalveolair trauma meldt zich onverwacht en meestal op een voor de tandarts ongelegen moment. Toch moet deze patiënt met spoed op adequate wijze worden geholpen. Om daarbij geen afwijkingen over het hoofd te zien, is het sterk aan te bevelen de diagnostiek volgens een vast schema te laten plaatsvinden. In dit artikel wordt beschreven hoe de diagnostiek en de behandeling van de patiënt met een dentoalveolair letsel gestructureerd kunnen plaatsvinden. Ook wordt een overzicht gegeven van de klinische symptomen waarmee een dergelijk letsel gepaard kan gaan, worden richtlijnen gegeven voor de behandeling van de verschillende typen dentoalveolaire trauma´s en wordt aandacht besteed aan de prognose. Tot slot volgen nog enige aanbevelingen met betrekking tot de nazorg en de preventie.The dentist will be confronted unexpectedly with a dentoalveolar trauma patient. This patient has to be seen immediately and has to be treated adequately. The risk of overlooking trauma-related signs when examining these patients, can be minimized by following a strict protocol. This article describes a protocol for examination and treatment of a patient with a dentoalveolar trauma. The prognosis after treatment of the trauma is discussed. Also some recommendations regarding aftercare and prevention are presented.</p

    Dentoalveolar surgery for the dentist:removal of teeth and root tips

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    The indication for surgical removal of teeth or roottips is often made in dental practice. In some cases a general practitioner will decide to perform the surgical procedure himself, while in other cases he will refer the patient to an oral and maxillofacial surgeon. Level of difficulty of the treatment and the experience, the time available, the availability for postoperative care, and the personal interest of the dentist are factors involved in decision making. It is likely that with increased experience, the dentist will be able to perform more complicated treatments. This article supports this process. Surgical removal of teeth and roottips is systematically described, with emphasis on technical aspects. Presurgical management, removal of singlerooted and multirooted teeth, woundcare and postoperative management are the subjects covered.</p

    Dentoalveolar surgery for the dentist:removal of third molar

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    In contrast to removal of other teeth and roottips, a third molar is mostly removed for preventive reasons. There is still debate about the correct indications for removal of third molars. As soon as the decision to remove a third molar surgically is made, the dentist has to decide between performing the surgical procedure himself or referring the patient to an oral and maxillofacial surgeon. Level of difficulty of the treatment and experience, available time, availability for postoperative care, and personal interest of the dentist are issues influencing this decision. This article describes systematically the indications, for instance using preoperative radiodiagnostics, the factors determining the technical surgical plan, as well as the practical surgical procedures.</p

    Dentoalveolar surgery for the dentist:removal of third molar

    Get PDF
    In contrast to removal of other teeth and roottips, a third molar is mostly removed for preventive reasons. There is still debate about the correct indications for removal of third molars. As soon as the decision to remove a third molar surgically is made, the dentist has to decide between performing the surgical procedure himself or referring the patient to an oral and maxillofacial surgeon. Level of difficulty of the treatment and experience, available time, availability for postoperative care, and personal interest of the dentist are issues influencing this decision. This article describes systematically the indications, for instance using preoperative radiodiagnostics, the factors determining the technical surgical plan, as well as the practical surgical procedures.</p

    Dentoalveolar surgery for the dentist:removal of teeth and root tips

    Get PDF
    The indication for surgical removal of teeth or roottips is often made in dental practice. In some cases a general practitioner will decide to perform the surgical procedure himself, while in other cases he will refer the patient to an oral and maxillofacial surgeon. Level of difficulty of the treatment and the experience, the time available, the availability for postoperative care, and the personal interest of the dentist are factors involved in decision making. It is likely that with increased experience, the dentist will be able to perform more complicated treatments. This article supports this process. Surgical removal of teeth and roottips is systematically described, with emphasis on technical aspects. Presurgical management, removal of singlerooted and multirooted teeth, woundcare and postoperative management are the subjects covered.</p
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