A commissioning protocol for portal imaging-based radiotherapy in vivo dosimetry systems.

Background And Purpose: With the availability of commercial electronic portal imaging detector-based in vivo dosimetry (EPID-based IVD) solutions, many radiotherapy departments are adopting this technology. However, comprehensive commissioning guidance is lacking. This study aims to provide a protocol for testing the accuracy and sensitivity of EPID-based IVD systems.

Allele Frequencies of Genetic Variants Associated with Varroa Drone Brood Resistance (DBR) in Subspecies across the European Continent.

Implementation of marker-assisted selection (MAS) in modern beekeeping would improve sustainability, especially in breeding programs aiming for resilience against the parasitic mite . Selecting honey bee colonies for natural resistance traits, such as brood-intrinsic suppression of varroa mite reproduction, reduces the use of chemical acaricides while respecting local adaptation. In 2019, eight genomic variants associated with varroa non-reproduction in drone brood were discovered in a single colony from the Amsterdam Water Dune population in the Netherlands.

Comprehensive Approach to Phenotype Reproduction in Honey Bee Drone Brood and Its Correlation with Decreased Mite Reproduction (DMR).

The mechanisms of action behind decreased mite reproduction (DMR) are still unknown, but current hypotheses state that DMR is the result of brood-intrinsic and/or external disturbances in the -honey bee pupa signal interactions. For accurate and precise DMR phenotyping, sufficient single infested honey bee brood cells are required (e.g.

The use of in-vivo dosimetry to identify head and neck cancer patients needing adaptive radiotherapy.

Background And Purpose: Head and neck cancer (HNC) patients experiencing anatomical changes during their radiotherapy (RT) course may benefit from adaptive RT (ART). We investigated the sensitivity of an electronic portal imaging device (EPID)-based in-vivo dosimetry (EIVD) system to detect patients that require ART and identified its limitations.

Materials And Methods: A retrospective study was conducted for 182 HNC patients: laryngeal cancer without elective lymph nodes (group A), postoperative RT (group B) and primary RT including elective lymph nodes (group C).

Assessing the impact of adaptations to the clinical workflow in radiotherapy using transit in vivo dosimetry.

Background And Purpose: Currently in-vivo dosimetry (IVD) is primarily used to identify individual patient errors in radiotherapy. This study investigated possible correlations of observed trends in transit IVD results, with adaptations to the clinical workflow, aiming to demonstrate the possibility of using the bulk data for continuous quality improvement.

Materials And Methods: In total 84,100 transit IVD measurements were analyzed of all patients treated between 2018 and 2022, divided into four yearly periods.

Comparing treatment uncertainty for ultra- vs. standard-hypofractionated breast radiation therapy based on in-vivo dosimetry.

Background And Purpose: Postoperative ultrahypofractionated radiation therapy (UHFRT) in 5 fractions (fx) for breast cancer patients is as effective and safe as conventionally hypofractionated RT (HFRT) in 15 fx, liberating time for higher-level daily online Image-Guided Radiation Therapy (IGRT) corrections. In this retrospective study, treatment uncertainties occurring in patients treated with 5fx (5fx-group) were evaluated using electronic portal imaging device (EPID)-based in-vivo dosimetry (EIVD) and compared with the results from patients treated with conventionally HFRT (15fx-group) to validate the new technique and to evaluate if the shorter treatment schedule could have a positive effect on the treatment uncertainties.

Materials And Methods: EPID-based integrated transit dose images were acquired for each treatment fraction in the 5fx-group (203 patients) and on the first 3 days of treatment and weekly thereafter in the 15fx-group (203 patients).

Evaluation of automated pre-treatment and transit in-vivo dosimetry in radiotherapy using empirically determined parameters.

Background And Purpose: First reports on clinical use of commercially automated systems for Electronic Portal Imaging Device (EPID)-based dosimetry in radiotherapy showed the capability to detect important changes in patient setup, anatomy and external device position. For this study, results for more than 3000 patients, for both pre-treatment verification and in-vivo transit dosimetry were analyzed.

Materials And Methods: For all Volumetric Modulated Arc Therapy (VMAT) plans, pre-treatment quality assurance (QA) with EPID images was performed.

In vivo dosimetry for patients with prostate cancer to assess possible impact of bladder and rectum preparation.

Purpose/objective: In all treatment sites of our radiotherapy network, in vivo dosimetry (PerFRACTION™) was fully implemented in February 2018. We hypothesized that additional help with bladder and rectum preparation by home nursing would improve patients' preparation and investigated if this could be assessed using in vivo dosimetry (IVD).

Materials/methods: A retrospective study was conducted with a test group who received additional help with bladder and rectum preparation by home nurses and a control group who only received information on bladder and rectum preparation according to the standard protocol.

The role of stimulus-driven versus goal-directed processes in fight and flight tendencies measured with motor evoked potentials induced by Transcranial Magnetic Stimulation.

This study examines two contrasting explanations for early tendencies to fight and flee. According to a stimulus-driven explanation, goal-incompatible stimuli that are easy/difficult to control lead to the tendency to fight/flee. According to a goal-directed explanation, on the other hand, the tendency to fight/flee occurs when the expected utility of fighting/fleeing is the highest.

Molecular Analysis of Rising Fluoroquinolone Resistance in Belgian Non-Invasive Streptococcus pneumoniae Isolates (1995-2014).

We present the results of a longitudinal surveillance study (1995-2014) on fluoroquinolone resistance (FQ-R) among Belgian non-invasive Streptococcus pneumoniae isolates (n = 5,602). For many years, the switch to respiratory fluoroquinolones for the treatment of (a)typical pneumonia had no impact on FQ-R levels. However, since 2011 we observed a significant decrease in susceptibility towards ciprofloxacin, ofloxacin and levofloxacin with peaks of 9.

Unexpected and just missed: the separate influence of the appraisals of expectancy and proximity on negative emotions.

Previous research has suggested that a goal-incongruent outcome leads to more intense negative emotions when it is unexpected and close to a goal-congruent outcome. Until now, however, no studies have disentangled the influence of the appraisals of expectancy and proximity on emotions. We experimentally manipulated each of these variables in 3 slot machine experiments and measured emotions via differences in motivation (i.

10th survey of antimicrobial resistance in noninvasive clinical isolates of Streptococcus pneumoniae collected in Belgium during winter 2007-2008.

Objectives: The aim of the study was to evaluate the antibiotic resistance in noninvasive clinical isolates of Streptococcus pneumoniae collected in Belgium during winter 2008-2007.

Method: Four hundred and forty eight unduplicated isolates collected by 15 laboratories were tested by microdilution following CLSI.

Results: Insusceptibility rates (I+R) were as follows: penicillin G (PEN) 11.

New phage type among methicillin-resistant Staphylococcus aureus associated with a local outbreak in Belgium during 2002.

In total, 150 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected during 2002 from a general Belgian hospital were phage-typed at routine test dilution x 100. The majority (45%) belonged to phage group (J)*, while 10% were classified as a new phage type 29/(42E)/54/(D11)*. The isolates belonging to this new type carried the aac(6')-aph(2'') and the aph(3') aminoglycoside resistance genes and showed high-level resistance to oxacillin.

Surveillance of antibiotic resistance in non invasive clinical isolates of Streptococcus pneumoniae collected in Belgium during winters 2003 and 2004.

A total of 391 and 424 non-invasive isolates of Streptococcus pneumoniae collected by 15 laboratories during the 2003 and 2004 survey were tested for their susceptibility by a microdilution technique following NCCLS recommendations. Insusceptibility rates (IR) in the two surveys (2003/2004) were as follows: penicillin 15.0/14.

High prevalence of penicillin resistance and comparative in vitro activity of various antibiotics in clinical isolates of streptococcus pneumoniae isolated in the Province of Hainaut during winter 2004.

A total of 154 isolates of Streptococcus pneumoniae obtained from 8 different centres in the province of Hainaut were included in this study. The susceptibilities to penicillin, amoxicillin, cefuroxime, ciprofloxacin, moxifloxacin, erythromycin and tetracycline were determined by a microdilution technique following NCCLS recommendations. Decreased susceptibility to penicillin was 32.

A change in Belgian epidemic methicillin-resistant Staphylococcus aureus phage types in 2000: phenotypic and genotypic characterization of isolates from a general hospital.

During 2000, new methicillin-resistant Staphylococcus aureus (MRSA) epidemic phage types became preponderant in Belgium. In the present study, phenotypic and genotypic characteristics of 130 MRSA isolates from a general Belgian hospital were investigated. The MRSA nature of the isolates was confirmed by coagulase test, oxacillin screen plate test and detection of the mecA gene by polymerase chain reaction.

Surveillance of antibiotic resistance in clinical isolates of Streptococcus pneumoniae collected in Belgium during winter 2000-2001.

A total of 314 isolates of Streptococcus pneumoniae collected by 10 different laboratories were tested for their susceptibility by using a microdilution technique following NCCLS recommendations. The following antibiotics were included: penicillin, ampicillin, amoxicillin, amoxicillin/clavulanate, cefaclor, cefuroxime, cefotaxime, imipenem, ciprofloxacin, gemifloxacin, levofloxacin, erythromycin, clarithromycin, azithromycin, miocamycin, clindamycin and tetracycline. The insusceptibility rate (IR) to penicillin was 21.

Aminoglycoside resistance in Gram-negative blood isolates from various hospitals in Belgium and the Grand Duchy of Luxembourg. Aminoglycoside Resistance Study Group.

A total of 1102 consecutive clinical blood isolates, including 897 Enterobacteriaceae and 205 non-fermenting bacilli, were obtained from 13 university and university-affiliated hospitals, which were divided into a Northern and a Southern group. Resistance to gentamicin, tobramycin, netilmicin, amikacin and isepamicin was determined using a microdilution technique according to NCCLS procedures. The overall mean resistance level was 5.

Characterization of the 6'-N-aminoglycoside acetyltransferase gene aac(6')-Im [corrected] associated with a sulI-type integron.

The amikacin resistance gene aac(6')-Im [corrected] from Citrobacter freundii Cf155 encoding an aminoglycoside 6'-N-acetyltransferase was characterized. The gene was identified as a coding sequence of 521 bp located down-stream from the 5' conserved segment of an integron. The sequence of this aac(6')-Im [corrected] gene corresponded to a protein of 173 amino acids which possessed 64.

Changes in major populations of methicillin-resistant Staphylococcus aureus in Belgium.

A total of 102 epidemic methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 13 Belgian hospitals during two periods (1981-1985 and 1991-1992) were tested for phage-type, for the presence of aminoglycoside-modifying enzymes (AME), and examined by arbitrarily primed polymerase chain reaction (AP-PCR). All isolates, but five, belonged to a few distinct phage-types of group III. Most isolates expressed a combination of AAC(6')-APH(2") with APH(3')III, and ANT(4',4") or both.

Use of the polymerase chain reaction (PCR) for the detection of aacA genes encoding aminoglycoside-6'-N-acetyltransferases in reference strains and gram-negative clinical isolates from two Belgium hospitals.

Genes encoding aminoglycoside 6'-N-acetyltransferases, were identified using the polymerase chain reaction (PCR). Four sets of primers delineating DNA fragments of 209 bp, 250 bp, 260 bp and 347 bp, specific for the four known aacA genes, and probes within these fragments, were constructed based on the nucleotide sequences of the aacA genes. The specificity of the primers was evaluated using reference strains encoding various aminoglycoside-modifying enzymes.

Identification of the aadB gene coding for the aminoglycoside-2"-O-nucleotidyltransferase, ANT(2"), by means of the polymerase chain reaction.

The polymerase chain reaction (PCR) was used to identify the gene encoding the aminoglycoside-2"-O-nucleotidyltransferase, ANT(2"). Two primers, delineating a DNA fragment of 188 bp, and a specific probe within this fragment were constructed, based on the nucleotide sequence of the aadB gene encoding this enzyme. Reference strains producing different aminoglycoside-modifying enzymes were used to evaluate the specificity and the sensitivity of the test.