An Inter-observer Study to Determine Radiotherapy Planning Target Volumes for Recurrent Gynaecological Cancer Comparing Magnetic Resonance Imaging Only With Computed Tomography-Magnetic Resonance Imaging

AIMS

Target delineation uncertainty is arguably the largest source of geometric uncertainty in radiotherapy. Several factors can affect it, including the imaging modality used for delineation. It is accounted for by applying safety margins to the target to produce a planning target volume (PTV), to which treatments are designed. To determine the margin, the delineation uncertainty is measured as the delineation error, and then a margin recipe used. However, there is no published evidence of such analysis for recurrent gynaecological cancers (RGC). The aims of this study were first to quantify the delineation uncertainty for RGC gross tumour volumes (GTVs) and to calculate the associated PTV margins and then to quantify the difference in GTV, delineation uncertainty and PTV margin, between a computed tomography-magnetic resonance imaging (CT-MRI) and MRI workflow.

MATERIALS AND METHODS

Seven clinicians delineated the GTV for 20 RGC tumours on co-registered CT and MRI datasets (CT-MRI) and on MRI alone. The delineation error, the standard deviation of distances from each clinician's outline to a reference, was measured and the required PTV margin determined. Differences between using CT-MRI and MRI alone were assessed.

RESULTS

The overall delineation error and the resulting margin were 3.1 mm and 8.5 mm, respectively, for CT-MRI, reducing to 2.5 mm and 7.1 mm, respectively, for MRI alone. Delineation errors and therefore the theoretical margins, varied widely between patients. MRI tumour volumes were on average 15% smaller than CT-MRI tumour volumes.

DISCUSSION

This study is the first to quantify delineation error for RGC tumours and to calculate the corresponding PTV margin. The determined margins were larger than those reported in the literature for similar patients, bringing into question both current margins and margin calculation methods. The wide variation in delineation error between these patients suggests that applying a single population-based margin may result in PTVs that are suboptimal for many. Finally, the reduced tumour volumes and safety margins suggest that patients with RGC may benefit from an MRI-only treatment workflow.

Preferential grazing and repackaging of small polyethylene microplastic particles (≤ 5 μm) by the ciliate Sterkiella sp

Microplastic (MP) particles are pollutants of global concern and are ubiquitously distributed in the ocean by physical and biological processes. It has been shown that zooplankton can ingest MP yet the interaction between ciliates and MP is still poorly understood. The discrimination and preferential uptake of MP rather than algal prey by ciliates was assessed in this study. The ciliate Sterkiella sp. was fed a diet that consisted of only Isochrysis galbana or a mixture of the same algae and similarly sized polyethylene beads in a 1:3 ratio. Significant, preferential MP grazing was observed in the Plastic-Algae treatment, which is the first reported evidence of proto-zooplankton preferentially ingesting MP over algal food. The mixed treatment contained fecal pellets with embedded MP. Preferential uptake of MP suggests that Sterkiella sp. is capable of ingesting and then "repackaging" MP that would otherwise be too small for larger taxa. This process would thus offer a mechanism for the reintroduction of MP into different compartments of the marine food web. As a consequence, it is necessary to account for small-sized MP (<5 μm) particles, that may have additional and yet unknown, impacts on marine food webs.

Impact of catheter ablation on HFpEF in people with comorbid atrial fibrillation and HFpEF using invasive haemodynamic testing

Background

The impact of catheter ablation (CA) for atrial fibrillation (AF) in patients with heart failure with preserved ejection fraction (HFpEF) is unknown.

Objectives

To determine whether CA for AF reverses adverse haemodynamic changes associated with HFpEF.

Methods

Consecutive consenting patients with EF ≥50% scheduled for index CA underwent baseline exercise right heart catheterisation (exRHC), cardiac output (CO) measurement, cardiac MRI, echocardiogram, QOL questionnaires and BNP testing. HFpEF was defined by resting pulmonary capillary wedge pressure (PCWP) ≥15mmHg or peak exercise PCWP ≥25 mmHg during exRHC. Patients with HFpEF were offered follow-up exRHC ≥6 months post-CA.

Results

Of 252 patients scheduled for CA between April 2017 and Sept 2019, 131 (51.9%) qualified for inclusion, 65 (49.6%) consented to exRHC and 11 (16.9%) were excluded due to a subsequent decrease in EF (10) and uncontrolled hypertension (1). Fifty-four underwent exRHC, with 35 (65%) meeting criteria for HFpEF. Of them 26 (74.3%) who underwent CA, 20 (77%) had a follow up exRHC at 12±6 months follow-up, showing an overall decrease in peak exercise PCWP from 30.3±4.2 to 26.8±4.7 mmHg (p&lt;0.05). Patients without arrhythmia recurrence showed significant improvements in peak exercise PCWP (29.2±3.7 to 22.9±2.0 mmHg (p&lt;0.01). Their cardiac output increased from 10.3±3.0 to 12.1±4.0 mmHg p=0.1), and BNP decreased from (94.6±101.6 to 38.0±34.0 mmHg (p=0.06),whereas those with arrhythmia recurrence did not. Overall, 9 patients (45.0%) no longer met criteria for HFpEF.

Conclusion

There is a high prevalence of HFpEF in people referred for AF ablation. Successful CA for AF reverses the adverse haemodynamic changes associated with HFpEF

Changes in PCWP following AF ablation

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): NHMRC, NHF, RACP

Considerations for Antiplatelet Management of Carotid Stenting in the Setting of Mechanical Thrombectomy: A Delphi Consensus Statement

BACKGROUND AND PURPOSE

There are only few data and lack of consensus regarding antiplatelet management for carotid stent placement in the setting of endovascular stroke treatment. We aimed to develop a consensus-based algorithm for antiplatelet management in acute ischemic stroke patients undergoing endovascular treatment and simultaneous emergent carotid stent placement.

MATERIALS AND METHODS

We performed a literature search and a modified Delphi approach used Web-based questionnaires that were sent in several iterations to an international multidisciplinary panel of 19 neurointerventionalists from 7 countries. The first round included open-ended questions and formed the basis for subsequent rounds, in which closed-ended questions were used. Participants continuously received feedback on the results from previous rounds. Consensus was defined as agreement of ≥70% for binary questions and agreement of ≥50% for questions with >2 answer options. The results of the Delphi process were then summarized in a draft manuscript that was circulated among the panel members for feedback.

RESULTS

A total of 5 Delphi rounds were performed. Panel members preferred a single intravenous aspirin bolus or, in jurisdictions in which intravenous aspirin is not available, a glycoprotein IIb/IIIa receptor inhibitor as intraprocedural antiplatelet regimen and a combination therapy of oral aspirin and a P2Y12 inhibitor in the postprocedural period. There was no consensus on the role of platelet function testing in the postprocedural period.

CONCLUSIONS

More and better data on antiplatelet management for carotid stent placement in the setting of endovascular treatment are urgently needed. Panel members preferred intravenous aspirin or, alternatively, a glycoprotein IIb/IIIa receptor inhibitor as an intraprocedural antiplatelet agent, followed by a dual oral regimen of aspirin and a P2Y12 inhibitor in the postprocedural period.

Antiplatelet Management for Stent-Assisted Coiling and Flow Diversion of Ruptured Intracranial Aneurysms: A DELPHI Consensus Statement

BACKGROUND AND PURPOSE

There is a paucity of data regarding antiplatelet management strategies in the setting of stent-assisted coiling/flow diversion for ruptured intracranial aneurysms. This study aimed to identify current challenges in antiplatelet management during stent-assisted coiling/flow diversion for ruptured intracranial aneurysms and to outline possible antiplatelet management strategies.

MATERIALS AND METHODS

The modified DELPHI approach with an on-line questionnaire was sent in several iterations to an international, multidisciplinary panel of 15 neurointerventionalists. The first round consisted of open-ended questions, followed by closed-ended questions in the subsequent rounds. Responses were analyzed in an anonymous fashion and summarized in the final manuscript draft. The statement received endorsement from the World Federation of Interventional and Therapeutic Neuroradiology, the Japanese Society for Neuroendovascular Therapy, and the Chinese Neurosurgical Society.

RESULTS

Data were collected from December 9, 2019, to March 13, 2020. Panel members achieved consensus that platelet function testing may not be necessary and that antiplatelet management for stent-assisted coiling and flow diversion of ruptured intracranial aneurysms can follow the same principles. Preprocedural placement of a ventricular drain was thought to be beneficial in cases with a high risk of hydrocephalus. A periprocedural dual, intravenous, antiplatelet regimen with aspirin and a glycoprotein IIb/IIIa inhibitor was preferred as a standard approach. The panel agreed that intravenous medication can be converted to oral aspirin and an oral P2Y12 inhibitor within 24 hours after the procedure.

CONCLUSIONS

More and better data on antiplatelet management of patients with ruptured intracranial aneurysms undergoing stent-assisted coiling or flow diversion are urgently needed. Panel members in this DELPHI consensus study preferred a periprocedural dual-antiplatelet regimen with aspirin and a glycoprotein IIb/IIIa inhibitor.

The effect of an ultrasound-activated needle tip tracker needle on the performance of sciatic nerve block on a soft embalmed Thiel cadaver

In this study, we measured the performance of medical students and anaesthetists using a new tracker needle during simulated sciatic nerve block on soft embalmed cadavers. The tracker needle incorporates a piezo element near its tip that generates an electrical signal in response to insonation. A circle, superimposed on the ultrasound image surrounding the needle tip, changes size and colour according to the position of the piezo element within the ultrasound beam. Our primary objective was to compare sciatic block performance with the tracker switched on and off. Our secondary objectives were to record psychometrics, procedure efficiency, participant self-regulation and focused attention using eye-tracking technology. Our primary outcome measures were the number of steps successfully performed and the number of errors committed during each block. Videos were scored by trained experts using validated checklists. Sequential tracker activation and deactivation was randomised equally within subjects. With needle activation, steps improved in 10 (25%) subjects and errors reduced in six (15%) subjects. The most important steps were: needle tip identification before injection, OR (95%CI) 2.12 (1.61-2.80; p < 0.001); and needle tip identification before advance of the needle, 1.80 (1.36-2.39; p < 0.001). The most important errors were: failure to identify the needle tip before injection, 2.40 (1.78-3.24; p < 0.001); and failure to quickly regain needle tip position when tip visibility was lost, 2.03 (1.5-2.75; p < 0.001). In conclusion, needle-tracking technology improved performance in a quarter of subjects.

Application of spike sorting algorithm to neuronal signals originated from boron doped diamond micro-electrode arrays

In this work we report on the implementation of methods for data processing signals from microelectrode arrays (MEA) and the application of these methods for signals originated from two types of MEAs to detect putative neurons and sort them into subpopulations. We recorded electrical signals from firing neurons using titanium nitride (TiN) and boron doped diamond (BDD) MEAs. In previous research, we have shown that these methods have the capacity to detect neurons using commercially-available TiN-MEAs. We have managed to cultivate and record hippocampal neurons for the first time using a newly developed custom-made multichannel BDD-MEA with 20 recording sites. We have analysed the signals with the algorithms developed and employed them to inspect firing bursts and enable spike sorting. We did not observe any significant difference between BDD- and TiN-MEAs over the parameters, which estimated spike shape variability per each detected neuron. This result supports the hypothesis that we have detected real neurons, rather than noise, in the BDD-MEA signal. BDD materials with suitable mechanical, electrical and biocompatibility properties have a large potential in novel therapies for treatments of neural pathologies, such as deep brain stimulation in Parkinson's disease.

0886 Changes in Parent Knowledge and Self-Efficacy and Association With Adherence Following the Steps Towards Achieving Restful Sleep (STARS) Pediatric PAP Therapy Desensitization Program

Introduction

Obstructive sleep apnea (OSA) presents in 2-5 % of youth and has been consistently linked to sleepiness, cognitive deficits, behavior difficulties, and cardiovascular morbidity. PAP effectively treats OSA, however, nonadherence is the most common cause of PAP treatment failure in children. Few adherence interventions have been empirically studied for youth with OSA. The STARS (Steps Towards Achieving Restful Sleep) Clinic is a behavioral program to optimize child tolerance to PAP therapy through a parent class, and in vivo practice. The goal of the study was to examine parent knowledge and self-efficacy following participation in STARS, and associations with subsequent PAP adherence.

Methods

A retrospective chart review was conducted for patients in the STARS program. Items queried included patient demographics, diagnostic and treatment characteristics, pre- and post- STARS responses to a parent self-efficacy and knowledge questionnaire, and polysomnography and PAP adherence data. Paired-samples t-tests examined changes in parent self-efficacy and knowledge pre- to post STARS, and regression analyses examined associations between self-efficacy and knowledge with demographics, treatment-related characteristics, and PAP adherence.

Results

130 patients completed the STARS program from October 2016 to February 2019. Participants were 8.3 years old ±6.3, 63% male, 57% white, 33% Hispanic, with severe OSA (OAHI =22 ±33). Most participants (87%) had at least one medical comorbidity (e.g, Down Syndrome, 41%). Both parent knowledge and self-efficacy increased significantly from pre- to post- STARS. Approximately 60% of patients were adherent following STARS (defined as ≥4 h use and ≥70% of days used). Higher post- knowledge, but not efficacy score, was significantly associated with better PAP adherence.

Conclusion

Parent knowledge and self-efficacy for PAP improved following the STARS program, and greater knowledge was associated with better adherence. Future research evaluating the efficacy and effectiveness of the STARS program is needed but preliminary evidence suggests it may be a promising model for improving youth PAP adherence.

Support

None

Persistence and compliance with osteoporosis therapies among postmenopausal women in the UK Clinical Practice Research Datalink

Gaining full benefits from osteoporosis medications requires long-term treatment. Investigating the real-world persistence of women receiving osteoporosis medications in the UK, we found that most patients stop treatment within a year. To prevent osteoporotic fragility fractures, long-term treatment persistence must be improved.

INTRODUCTION

Persistence with osteoporosis therapies has historically been poor. To treat this chronic and progressive disease, it is essential that patients receive the full benefit of these medications. We estimated persistence and compliance with osteoporosis therapies in a large sample of postmenopausal women in the UK.

METHODS

Data were obtained from the Clinical Practice Research Datalink for all women aged 50 years and over or women with early menopause, who received at least one prescription in primary care for any licensed osteoporosis therapy between January 1, 2010 and December 31, 2015. Persistence and compliance at 24 months (primary objective) and at 5 years (exploratory objective) were estimated in three patient cohorts: "All Patients," "Naïve Patients," and "Drug-Specific."

RESULTS

The All Patients cohort included 72,256 women. Persistence with any therapy was 56.1%, 43.6%, 36.4%, and 31.0% at 6, 12, 18, and 24 months, respectively, and 23.2% and 13.1% at 3 years and 5 years, respectively. Patients were generally more persistent and compliant if evaluated from their first exposure to osteoporosis therapy (Naïve Patients cohort). In the drug-specific analysis, 64% of patients receiving denosumab (administered subcutaneously every 6 months) were persistent at 24 months compared with 28% and 23% of those taking oral bisphosphonates and intravenous bisphosphonates, respectively.

CONCLUSIONS

Only about one in three patients who received osteoporosis therapy continued to be on treatment after 2 years. There is a need to improve persistence with osteoporosis therapy, especially for high-risk patients.

Using predicted imports of 2019-nCoV cases to determine locations that may not be identifying all imported cases

Cases from the ongoing outbreak of atypical pneumonia caused by the 2019 novel coronavirus (2019-nCoV) exported from mainland China can lead to self-sustained outbreaks in other populations. Internationally imported cases are currently being reported in several different locations. Early detection of imported cases is critical for containment of the virus. Based on air travel volume estimates from Wuhan to international destinations and using a generalized linear regression model we identify locations which may potentially have undetected internationally imported cases.

70 Prevalence of Sarcopenia in A Longitudinal UK Cohort Study Using Ewgsop2 Criteria Varies Widely Depending on Which Measures of Muscle Strength and Performance are Used

Background

The European Working Group on Sarcopenia in Older People 2 (EWGSOP2) guidelines have recently been published to aid diagnosis of sarcopenia in the clinical setting and to allow for better comparison between research studies. The guidelines recommend several different tests for diagnosing sarcopenia. We hypothesised that the prevalence of sarcopenia might vary depending on which tests are used.

Methods

We used data from Wave 3 of the Lothian Birth Cohort 1936 study, a longitudinal ageing study of healthy, community dwelling older adults (n= 697, 52% men, mean age 76y), to assess the prevalence of sarcopenia using the suggested cut-offs in the EWGSOP2 guidelines. Probable sarcopenia was defined as low muscle strength (measured by handgrip strength and 5x chair stand test), confirmed sarcopenia was defined as low muscle strength + low lean mass (measured by bioimpedance analysis), and severe sarcopenia was defined as confirmed sarcopenia + low muscle performance (measured by gait speed and short physical performance battery score). SPSS version 24.0 was used for statistical analysis.

Results

The maximum prevalence of probable sarcopenia was 24.2% in men and 24.8% in women, of confirmed sarcopenia was 7.4% in men and 11.0% in women, and of severe sarcopenia was 4.6% in men and 5.9% in women, when either of the cut-offs for muscle strength +/- muscle performance were met. When using only one measure of muscle strength +/- performance, rates of probable sarcopenia ranged from 7.7% to 21.1% in men and 5.9% to 21.3% in women; rates of confirmed sarcopenia ranged from 3.9% to 5.3% in men and 5.1% to 9% in women; and rates of severe sarcopenia ranged from 1.4% to 3.9% in men and from 2.0% to 5.1% in women.

Conclusions

In a UK-based longitudinal ageing study we found that the prevalence of probable, confirmed and severe sarcopenia varied widely using the EWGSOP2 guidelines depending on which identifying tests were used. We found that the cut-off points suggested for some of the measures in the guidelines are not comparable and may lead to differing groups being identified as sarcopenic between different trials. We suggest modification of the cut-offs to adjust for this.

Rugby World Cup 2019 injury surveillance study

Background

Full contact team sports, such as rugby union, have high incidences of injury. Injury surveillance studies underpin player welfare programmes in rugby union.

Objective

To determine the incidence, severity, nature and causes of injuries sustained during the Rugby World Cup 2019.

Methods

A prospective, whole population study following the definitions and procedures recommended in the consensus statement for epidemiologic studies in rugby union. Output measures included players' age (years), stature (cm), body mass (kg), playing position, and group-level incidence (injuries/1000 player-hours), severity (days-absence), injury burden (days absence/1000 player-hours), location (%), type (%) and inciting event (%) of injuries.

Results

Overall incidences of injury were 79.4 match injuries/1000 player-match-hours (95% CI: 67.4 to 93.6) and 1.5 training injuries/1000 player-training-hours (95% CI: 1.0 to 2.3). The overall mean severity of injury was 28.9 (95% CI: 20.0 to 37.8) days absence during matches and 14.8 (95% CI: 4.1 to 25.5) days absence during training. The most common locations and types of match injuries were head/face (22.4%), posterior thigh (12.6%), ligament sprain (21.7%) and muscle strain (20.3%); the ankle (24.0%), posterior thigh (16.0%), muscle strain (44.0%) and ligament sprain (16.0%) were the most common locations and types of injuries during training. Tackling (28.7%), collisions (16.9%) and running (16.9%) were responsible for most match injuries and non-contact (36.0%) and contact (32.0%) rugby skills activities for training injuries.

Conclusion

The incidence, severity, nature and inciting events associated with match and training injuries at Rugby World Cup 2019 were similar to those reported for Rugby World Cups 2007, 2011 and 2015.

RTT-led IGRT for cervix cancer; training, implementation and validation

INTRODUCTION

IGRT in cervical cancer treatment delivery is complex due to significant target and organs at risk (OAR) motion. Implementing image assessment of soft-tissue target and OAR position to improve accuracy is recommended. We report the development and refinement of a training and competency programme (TCP), leading to on-line Radiation Therapist (RTT) led soft-tissue assessment, evaluated by a prospective audit.

METHODS AND MATERIALS

The TCP comprised didactic lectures and practical sessions, supported by a comprehensive workbook. The content was decided by a team comprised of Clinical Oncologists, RTTs, and Physicists. On completion of training, RTT soft-tissue review proficiency (after bony anatomy registration) was assessed against a clinician gold-standard from a database of 20 cervical cancer CBCT images. Reviews were graded pass or fail based on PTV coverage assessment and decision taken in concordance with the gold-standard. Parity was set at ≥80% agreement.The initial TCP (stage one) focussed on offline verification and decision making. Sixteen RTTs completed this stage, four achieved ≥80%. This was not sufficient to support clinical implementation.The TCP was redesigned, more stringent review guidelines and greater anatomy teaching was added. TCP stage two focussed on online verification and decision making supported by a decision flowchart. Twenty-one RTTs completed this TCP, all achieved ≥80%. This supported clinical implementation of RTT-led soft-tissue review under prospective audit conditions.The prospective audit was conducted between March 2017 and August 2017. Daily online review was performed by two trained RTTs. Online review and decision making proficiency was evaluated by a clinician.

RESULTS

Thirteen patients were included in the audit. Daily online RTT-led IGRT was achieved for all 343 fractions. Two-hundred CBCT images were reviewed offline by the clinician; the mean number of reviews per patient was 15. 192/200 (96%) RTT image reviews were in agreement with clinician review, presenting excellent concordance.

DISCUSSION AND CONCLUSION

Multidisciplinary involvement in training development, redesign of the TCP and inclusion of summative competency assessment were important factors to support RTT skill development. Consequently, RTT-led cervical cancer soft-tissue IGRT was clinically implemented in the hospital.

Determination of β-Carotene in Supplements and Raw Materials by Reversed-Phase High Pressure Liquid Chromatography: Collaborative Study

Twelve laboratories representing 4 countries participated in an interlaboratory study conducted to determine all-trans-β-carotene and total β-carotene in dietary supplements and raw materials. Thirteen samples were sent as blind duplicates to the collaborators. Results obtained from 11 laboratories are reported. For products composed as softgels and tablets that were analyzed for total β-carotene, the reproducibility relative standard deviation (RSDR) ranged from 3.35 to 23.09% and the HorRat values ranged from 1.06 to 3.72. For these products analyzed for trans β-carotene, the reproducibility relative standard deviation (RSDR) ranged from 4.28 to 22.76% and the HorRat values ranged from 0.92 to 3.37. The RSDr and HorRat values in the analysis of a beadlet raw material were substantial and it is believed that the variability within the material itself introduced significant variation in subsampling. The method uses high pressure liquid chromatography (LC) in the reversed-phase mode with visible light absorbance for detection and quantitation. If high levels of α-carotenes are present, a second LC system is used for additional separation and quantitation of the carotene species. It is recommended that the method be adopted as an AOAC Official Method.

P3419Independent effects of visceral, subcutaneous and liver fat, and fat-free mass on cardiometabolic risk factors in teenagers

Acknowledgement/Funding

Alexander Jones is funded by a British Heart Foundation Intermediate Clinical Research Fellowship (FS/18/22/33479)

An initial evaluation of the effect of a novel regional block needle with tip-tracking technology on the novice performance of cadaveric ultrasound-guided sciatic nerve block

Visibility of the needle tip is difficult to maintain during ultrasound-guided nerve block. A new needle has been developed that incorporates a piezo element 2-2.3 mm from the tip, activated by ultrasound. The electrical signal manifests as a coloured circle surrounding the needle tip, and allows real-time tracking. We hypothesised that novice regional anaesthetists would perform nerve block better with the tracker turned on rather than off. Our primary objective was to evaluate the new needle by measuring the performance of novice anaesthetists conducting simulated sciatic block on the soft embalmed Thiel cadaver. Training consisted of a lecture, scanning in volunteers and practice on cadavers. Testing entailed scanning the sciatic nerve of a cadaver and conducting 20 in-plane sciatic blocks in the mid-to-upper thigh region. Subjects were randomised equally, in groups of five, according to the sequence: tracker on/off/on/off; or tracker off/on/off/on. Video recordings were assessed by six raters for steps performed correctly and errors committed. Eight subjects were recruited and 160 videos were analysed. Using the tracking needle, five correct steps improved and one error reduced. The benefits included: better identification of the needle tip before advancing the needle, OR (95%CI) 3.4 (1.6-7.7; p < 0.001); better alignment of the needle to the transducer, 3.1 (1.3-8.7; p = 0.009); and better visibility of the needle tip 3.0 (1.4-7.3; p = 0.005). In conclusion, use of the tracker needle improved the sciatic block performance of novices on the soft embalmed cadaver.

A66 Tracing the evolutionary history of an emerging Salmonella 4,[5],12:i:- clone in the United States

Salmonellosis is one of the leading causes of foodborne disease worldwide, with an estimated one million cases a year in the United States. Salmonella 4,[5],12: i:-, a monophasic variant of Salmonella typhimurium, is an emerging serovar that has been associated with multiple foodborne outbreaks throughout the world, mostly attributed to pig and pig products. Recently, we have demonstrated that two distinct groups of Salmonella 4,[5],12:i:- circulate in the USA and Europe, with the majority of isolates recovered during recent years belonging to an emerging multidrug-resistant clade (Elnekave et al. 2018). We applied Bayesian phylodynamic reconstruction to uncover the evolutionary history of this clade. We used a dataset of whole-genome sequences of 1446 4,[5],12:i:- isolates from different sources (livestock, human, food products, and others) from the USA (n = 752) and Europe (n = 694), collected between 2008 and 2017 and belonging to the Multilocus Subtype 34, which was predominant in the emerging clade (Elnekave et al. 2018). A subset (n = 110) of Salmonella 4,[5],12:i: isolates was then randomly selected after stratifying by location and year of isolation in order to achieve balanced sampling. Evidence of temporal signal was confirmed by looking at root-to-tip divergences using TempEst. Evolutionary hypotheses using strict and relaxed-clock models were tested using BEAST for a variety of demographic models and assuming a general time reversible substitution model. Model selection was performed by estimating Bayes Factors using path sampling and stepping-stone sampling. The selected model was then used for applying discrete trait models comparing different scenarios of transmission between locations (i.e. bidirectional symmetric/asymmetric or unidirectional). Our preliminary phylodynamic inference results indicate that the origin of this subtype was in Europe and dates back to 1990 (HPD 95%: 1984–2001). We report an exponential growth rate of 0.362 per year, which corresponds to a doubling time of 1.43 years. Our results suggest that this subtype was introduced to the US in the year 2000 (HPD 95%: 1994–2006). Phylodynamic analysis suggests that the recent increase in isolation of Salmonella 4,[5],12:i:- from different sources in the USA may be due to the exponential expansion of an emerging clone which originated in Europe and then expanded to the USA. The emergence and expansion of this serovar is of great public health importance due to the high prevalence of multidrug resistance traits found in USA isolates from this group and especially due to the presence of plasmid-mediated resistance genes for quinolones and extended spectrum cephalosporins, key antimicrobials used for the treatment of invasive Salmonella infections.

Clinical characteristics and outcome of dogs with presumed primary renal lymphoma

OBJECTIVES

To characterise the presentation, clinicopathologic data and outcome of 29 dogs with presumed primary renal lymphoma.

MATERIALS AND METHODS

Retrospective analysis of medical records of dogs with suspected primary renal lymphoma from 11 institutions.

RESULTS

All dogs were substage b, and lethargy and gastrointestinal signs were common presenting complaints, as were azotaemia (n=25; 86%) and erythrocytosis (n=15; 51%) on biochemical testing. Ultrasonography typically revealed bilateral renal lesions (n=23; 79%), renomegaly (n=22; 76%) and abdominal lymphadenopathy (n=14; 48%). Chemotherapy was the only treatment in 23 dogs, of which 11 responded, all considered partial responses. For all dogs the median progression-free survival and median overall survival times were 10 days (range: 1 to 126) and 12 days (range: 1 to 212), respectively, and for dogs that responded to chemotherapy 41 days (range: 10 to 126) and 47 days (range: 10 to 212), respectively.

CLINICAL SIGNIFICANCE

Primary renal lymphoma in dogs appears to be associated with a poor prognosis and short-lived response to chemotherapy.

Differential Relapse Patterns for Non-small Cell Lung Cancer Subtypes Adenocarcinoma and Squamous Cell Carcinoma: Implications for Radiation Oncology

AIMS

Curative-intent (radical) radiotherapy aims to control local disease and cure non-small cell lung cancer (NSCLC). The predominant subtypes of NSCLC are adenocarcinoma and squamous cell carcinoma (SCC). The radiotherapy paradigm offered to patients does not differ according to these two subtypes. Relapse patterns and disease control rates for adenocarcinoma and SCC treated with radical radiotherapy were determined.

MATERIALS AND METHODS

A radical radiotherapy database covering the period from 2004 to June 2016 was examined to determine the first sites of relapse and the actuarial local and distant control rates.

RESULTS

In total, 537 patients with known pathological subtype were treated over the period. In 39 (7%), the site of first relapse was uncertain. Of the remainder, 203 (41%) had adenocarcinoma and 295 (59%) had SCC. At a median follow-up of 16.4 months, 58% had relapsed. There was a difference in relapse patterns (chi-squared test P < 0.0005), with a higher rate of first relapse locally in SCC (42% of all patients versus 24%) and a higher rate of first relapse in the brain for adenocarcinoma (14% versus 3%). The actuarial local control rate was worse for SCC (hazard ratio 0.6, 95% confidence interval 0.5-0.9, P = 0.002). The brain metastasis-free survival was worse for adenocarcinoma (hazard ratio 4.1, 95% confidence interval 2.2-7.5, P < 0.0001).

CONCLUSION

There is a difference in relapse patterns between NSCLC histological subtypes, indicating that these are distinct entities. This may have implications for follow-up policy and strategies to improve disease control.

Initial results from the New Horizons exploration of 2014 MU69, a small Kuiper Belt object

The Kuiper Belt is a distant region of the outer Solar System. On 1 January 2019, the New Horizons spacecraft flew close to (486958) 2014 MU₆₉, a cold classical Kuiper Belt object approximately 30 kilometers in diameter. Such objects have never been substantially heated by the Sun and are therefore well preserved since their formation. We describe initial results from these encounter observations. MU₆₉ is a bilobed contact binary with a flattened shape, discrete geological units, and noticeable albedo heterogeneity. However, there is little surface color or compositional heterogeneity. No evidence for satellites, rings or other dust structures, a gas coma, or solar wind interactions was detected. MU₆₉'s origin appears consistent with pebble cloud collapse followed by a low-velocity merger of its two lobes.