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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., Material and Methods: The protocol was tested across four institutions using two different systems. Accuracy was evaluated with homogeneous slab phantoms using different square regular fields, and clinical plans in a CIRS lung phantom. Multiple forward and back-projected algorithm implementations were assessed for different energies. Sensitivity analysis in the lung phantom examined responses to setup errors, anatomical variations, and delivery errors., Results: In homogeneous phantoms, over 85 % of pixels passed the 5 %/2mm gamma criteria, except for the 2x2 cm 2 field. In the lung phantom, all systems and implementations achieved over 95 %-pixel pass rates at the 2 %/2mm criterion for volumetric modulated arc therapy (VMAT) plans. For conformal radiation therapy (3DCRT) plans, one system implementation showed poor accuracy, with over 90 % agreement only at the 5 %/2mm criterion. Considering all systems and implementations, average sensitivity and specificity for CRT plans ranged from 0.92 and 0.42 (at 2 %/2mm) to 0.71 and 0.52 (at 5 %/2mm), while for VMAT plans ranged from 0.41 and 0.81 (at 2 %2mm) to 0.37 and 0.81 (at 5 %/2mm)., Conclusion: We successfully developed a protocol to commission EPID IDV systems. It was found that not all systems and implementations achieved satisfactory accuracy and sensitivity, emphasising the need for thorough commissioning and benchmarking., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [The corresponding author is an Editorial Board Member for Physics and Imaging in Radiation Oncology and was not involved in the editorial review or the decision to publish this article. Núria Jornet is on the SunNuclear advisory board and SunNuclear reference site. Sara Brescani Candiolo Institute is a Sun Nuclear Reference site. Evy Bossuyt is on the SunNuclear advisory board and SunNuclear reference site. Dirk Verellen Iridium Netwerk, Antwerp is a SunNuclear reference site]., (© 2024 The Authors.)

Implementation of marker-assisted selection (MAS) in modern beekeeping would improve sustainability, especially in breeding programs aiming for resilience against the parasitic mite Varroa destructor . 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. Recently, a new study tested the applicability of these eight genetic variants for the same phenotype on a population-wide scale in Flanders, Belgium. As the properties of some variants varied between the two studies, one hypothesized that the difference in genetic ancestry of the sampled colonies may underly these contribution shifts. In order to frame this, we determined the allele frequencies of the eight genetic variants in more than 360 Apis mellifera colonies across the European continent and found that variant type allele frequencies of these variants are primarily related to the A. mellifera subspecies or phylogenetic honey bee lineage. Our results confirm that population-specific genetic markers should always be evaluated in a new population prior to using them in MAS programs.

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 V. destructor -honey bee pupa signal interactions. For accurate and precise DMR phenotyping, sufficient single infested honey bee brood cells are required (e.g., 35), which requires extensive labor and time and may exclude many samples not reaching the threshold. We defined a new comprehensive trait called the 'mean V. destructor reproduction rate' (mVR), which describes the mean number of offspring mites per infested cell in the sample while compensating for the reduced number of offspring with increasing multiple infested cells. We found a significant correlation between mVR and DMR, allowing for an estimation of DMR based on the mVR only. When the mVR was calculated with 10 infested cells, we found an average variation in mVR of 16.8%. For the same variation in DMR determination, 40 single infested cells are required. This broader look at V. destructor resistance phenotyping can improve the applicability and effectiveness of traits related to V. destructor reproduction in honey bee breeding programs.

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). The effect of anatomical changes on the dose distribution and volumetric changes was quantified. The receiver operating characteristic curve was used to obtain the optimal cut-off value for the gamma passing rate (%GP) with a dose difference of 3% and a distance to agreement of 3 mm., Results: Fifty HNC patients receiving ART were analyzed: 1 in group A, 10 in group B and 39 in group C. Failed fractions (FFs) occurred in 1/1, 6/10 and 23/39 cases before ART in group A, B and C respectively. In the four cases in group B without FFs, only minor dosimetric changes were observed. One of the cases in group C without FFs had significant dosimetric changes (false negative). Three cases received ART because of clinical reasons that cannot be detected by EIVD. The optimal cut-off value for the %GP was 95%/95.2% for old/new generation machines respectively., Conclusion: EIVD combined with 3D imaging techniques can be synergistic in the detection of anatomical changes in HNC patients who benefit from ART., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors have an on-going scientific collaboration with Sun Nuclear Corporation., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

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. Failed measurements (FM) were divided per pathology and into four categories of causes of failure: technical, planning and positioning problems, and anatomic changes., Results: The number of FM due to patient related problems gradually decreased from 9.5% to 6.6%, 6.1% and 5.6% over the study period. FM attributed to positioning problems decreased from 10.0% to 4.9% in boost breast cancer patients after introduction of extra imaging, from 9.1% to 3.9% in Head&Neck patients following education of radiation therapists on positioning of patients' shoulders, from 6.1% to 2.8% in breast cancer patients after introduction of ultrahypofractionated breast radiotherapy with daily online pre-treatment imaging and from 11.2% to 4.3% in extremities following introduction of immobilization with calculated couch parameters and a Surface Guided Radiation Therapy solution. FM related to anatomic changes decreased from 10.2% to 4.0% in rectum patients and from 6.7% to 3.3% in prostate patients following more patient education from dieticians., Conclusions: Our study suggests that IVD can be a powerful tool to assess the impact of adaptations to the clinical workflow and its use for continuous quality improvement., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

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). A total of 1015 EIVD measurements in the 5fx-group and 1144 in the 15fx-group were acquired. Of the latter group, 755 had been treated with online IGRT correction (i.e., Online-IGRT 15fx-group)., Results: In the 15fx-group 12.0% of fractions failed (FFs) compared to 3.8% in the 5fx-group and 6.9% in the online-IGRT 15fx-group. Causes for FFs in the 15fx-group compared with the 5fx-group were patient positioning (7.4% vs. 2.2%), technical issues (3.1% vs. 1.2%) and breast swelling (1.4% vs. 0.5%). In the online-IGRT 15fx-group, 2.5% were attributed to patient positioning, 3.8% to technical issues and 0.5% to breast swelling., Conclusions: EIVD demonstrated that UHFRT for breast cancer results in less FFs compared to standard HFRT. A large proportion of this decrease could be explained by using daily online IGRT., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors have an on-going scientific collaboration with Sun Nuclear Corporation., (© 2022 The Author(s).)

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. Patients were treated with a 6 MV Volumetric Modulated Arc Therapy (VMAT) technique. Electronic portal imaging device (EPID)-based integrated transit dose images were acquired on the first 3 days of treatment and weekly thereafter or more if failed fractions (FF) occurred. Results were analyzed using a global gamma analysis with a threshold of 20%, tolerance of 5% (dose difference) and 5 mm (distance to agreement), and a passing level of 95%., Results: Data of 462 prostate patients was analyzed: 39 and 423 in a test and control group respectively with a comparable number of measurements (on average 8.0 (σ = 4.8) and 7.1 (σ = 4.5) respectively per treatment course). Of the FF, 39% and 31% were related to variations in bladder and rectum filling for the test and control group respectively. Subgroups were created based on the number of FF, no statistically significant differences were observed., Conclusion: Two dimensional EPID-based IVD successfully detected deviations due to variations in bladder and rectum filling, however it could not confirm the hypothesis., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors have an on-going scientific collaboration with Sun Nuclear Corporation., (© 2020 The Authors.)

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 using transit EPID images was analyzed, including causes and actions for failed fractions for all patients receiving photon treatment (2018-2019). In total 3136 and 32,632 fractions were analyzed with pre-treatment and transit images respectively. Parameters for gamma analysis were empirically determined, balancing the rate between detection of clinically relevant problems and the number of false positive results., Results: Pre-treatment and in-vivo results depended on machine type. Causes for failed in-vivo analysis included deviations in patient positioning (32%) and anatomy change (28%). In addition, errors in planning, imaging, treatment delivery, simulation, breath hold and with immobilization devices were detected. Actions for failed fractions were mostly to repeat the measurement while taking extra care in positioning (54%) and to intensify imaging procedures (14%). Four percent initiated plan adjustments, showing the potential of the system as a basis for adaptive planning., Conclusions: EPID-based pre-treatment and in-vivo transit dosimetry using a commercially available automated system efficiently revealed a wide variety of deviations and showed potential to serve as a basis for adaptive planning., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Iridium Kankernetwerk is a member of the SunCHECK Customer Advisory Board and a Reference center for Sun Nuclear Corporation, but there has been no significant financial support for this work that could have influenced its outcome., (© 2020 The Authors.)

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. Participants did a computer task in which they were confronted with goal-incompatible stimuli that were (a) easy to control and fighting had the highest expected utility, (b) easy to control and fleeing had the highest expected utility, and (c) difficult to control and fleeing and fighting had zero expected utility. After participants were trained to use one hand to fight and another hand to flee, they either had to choose a response or merely observe the stimuli. During the observation trials, single-pulse Transcranial Magnetic Stimulation (TMS) was applied to the primary motor cortex 450 ms post-stimulus onset and motor-evoked potentials (MEPs) were measured from the hand muscles. Results showed that participants chose to fight/flee when the expected utility of fighting/fleeing was the highest, and that they responded late when the expected utility of both responses was low. They also showed larger MEPs for the right/left hand when the expected utility of fighting/fleeing was the highest. This result can be interpreted as support for the goal-directed account, but only if it is assumed that we were unable to override the presumed natural mapping between hand (right/left) and response (fight/flight)., Competing Interests: The authors have declared that no competing interests exist.

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.e., the tendency to repair the goal incongruence) and feelings (i.e., disappointment, frustration, and anger). The experiments consisted of a series of trials that each started with the sequential presentation of 3 symbols. In case of a win trial, all symbols were equal (e.g., AAA) and the participant gained 10 cents; in case of a loss trial, one or more of the symbols differed and the participant gained 0 cents. Three different loss trials were compared: unexpected proximal ones (e.g., AAB), expected proximal ones (e.g., ABA), and expected distal ones (e.g., ABC). The tendency to repair was measured online via behavior as well as retrospectively via self-reports; feelings were measured retrospectively (Experiments 1 and 2) or online (Experiment 3). Unexpected losses seemed to increase the tendency to repair as well as feelings of disappointment (in all experiments) and feelings of frustration and anger (in Experiments 1 and 3). Proximal losses increased only the tendency to repair (in all experiments). This suggests that the appraisals of expectancy and proximity have a distinct influence on emotions.