Systematic Implementation of Effective Quality Assurance Processes for the Assessment of Radiation Target Volumes in Head and Neck Cancer

PURPOSE

Significant heterogeneity exists in clinical quality assurance (QA) practices within radiation oncology departments, with most chart rounds lacking prospective peer-reviewed contour evaluation. This has the potential to significantly affect patient outcomes, particularly for head and neck cancers (HNC) given the large variance in target volume delineation. With this understanding, we incorporated a prospective systematic peer contour-review process into our workflow for all patients with HNC. This study aims to assess the effectiveness of implementing prospective peer review into practice for our National Cancer Institute Designated Cancer Center and to report factors associated with contour modifications.

METHODS AND MATERIALS

Starting in November 2020, our department adopted a systematic QA process with real-time metrics, in which contours for all patients with HNC treated with radiation therapy were prospectively peer reviewed and graded. Contours were graded with green (unnecessary), yellow (minor), or red (major) colors based on the degree of peer-recommended modifications. Contours from November 2020 through September 2021 were included for analysis.

RESULTS

Three hundred sixty contours were included. Contour grades were made up of 89.7% green, 8.9% yellow, and 1.4% red grades. Physicians with >12 months of clinical experience were less likely to have contour changes requested than those with <12 months (8.3% vs 40.9%; P < .001). Contour grades were significantly associated with physician case load, with physicians presenting more than the median number of 50 cases having significantly less modifications requested than those presenting <50 (6.7% vs 13.3%; P = .013). Physicians working with a resident or fellow were less likely to have contour changes requested than those without a trainee (5.2% vs 12.6%; P = .039). Frequency of major modification requests significantly decreased over time after adoption of prospective peer contour review, with no red grades occurring >6 months after adoption.

CONCLUSIONS

This study highlights the importance of prospective peer contour-review implementation into systematic clinical QA processes for HNC. Physician experience proved to be the highest predictor of approved contours. A growth curve was demonstrated, with major modifications declining after prospective contour review implementation. Even within a high-volume academic practice with subspecialist attendings, >10% of patients had contour changes made as a direct result of prospective peer review.

The value of standards for health datasets in artificial intelligence-based applications

Artificial intelligence as a medical device is increasingly being applied to healthcare for diagnosis, risk stratification and resource allocation. However, a growing body of evidence has highlighted the risk of algorithmic bias, which may perpetuate existing health inequity. This problem arises in part because of systemic inequalities in dataset curation, unequal opportunity to participate in research and inequalities of access. This study aims to explore existing standards, frameworks and best practices for ensuring adequate data diversity in health datasets. Exploring the body of existing literature and expert views is an important step towards the development of consensus-based guidelines. The study comprises two parts: a systematic review of existing standards, frameworks and best practices for healthcare datasets; and a survey and thematic analysis of stakeholder views of bias, health equity and best practices for artificial intelligence as a medical device. We found that the need for dataset diversity was well described in literature, and experts generally favored the development of a robust set of guidelines, but there were mixed views about how these could be implemented practically. The outputs of this study will be used to inform the development of standards for transparency of data diversity in health datasets (the STANDING Together initiative).

Phase I Study of Bortezomib, Fludarabine, and Melphalan, with or without Total Marrow Irradiation as Conditioning for Allogeneic Hematopoietic Stem Cell Transplantation in Patients with High-Risk or Relapsed/Refractory Multiple Myeloma

PURPOSE/OBJECTIVE(S)

Though outcomes of patients with multiple myeloma (MM) have improved, cure remains elusive. Allogeneic hematopoietic stem cell transplantation (allo-sCT) is associated with a lower relapse rate, but its role is hindered due to toxicities. We hypothesized that targeted total body irradiation in the form of total marrow irradiation (TMI) could safely facilitate allo-SCT via an improved toxicity profile. Therefore, we conducted a phase I study to investigate the safety and feasibility of a bortezomib (BTZ), fludarabine (FLU), and melphalan (MEL), with or without TMI, prior to allo-SCT for patients with high-risk (HR) or relapsed/refractory (R/R) MM.

MATERIALS/METHODS

Between 2012 and 2018 this study enrolled patients with HR or R/R MM on one of two strata, each comprising BTZ dose-escalation cohorts. Patients aged 18-60 with no prior radiation (RT) received TMI at 900 cGy (in 6 fractions delivered twice-daily), FLU, and MEL conditioning, with BTZ added in the second cohort (stratum I). Patients aged 18-70 with prior RT received FLU, MEL, and BTZ, without TMI (stratum II). The primary endpoint was feasibility of escalating doses of BTZ, with or without TMI, defined using a 3+3 design. Dose-limiting toxicity (DLT) was defined as any Grade 3+ Bearman toxicity or prolonged CTCAE v4.0 Grade 4+ neutropenia. Secondary endpoints included treatment response, time to neutrophil and platelet engraftment, incidence of acute (a) and chronic (c) graft-versus-host disease (GVHD), progression-free-survival (PFS), and overall survival (OS).

RESULTS

Eight patients were enrolled on stratum I. One of three patients in the first cohort of stratum I experienced DLT, which led to expansion to three more patients with no DLT. Cohort 2 enrolled only 2 patients due to low accrual, with BTZ added at 0.5 mg/m2; neither experienced DLT. Nine patients were enrolled on stratum II. Three patients were enrolled on cohort 1 (BTZ 0.5 mg/m2) and none experienced DLT. Three were enrolled on cohort 2 (bortezomib 0.7 mg/m2), and one experienced DLT. Therefore, the cohort expanded to three more patients. One more patient experienced DLT and 0.5 mg/m2 was considered the maximum tolerated dose. There were no primary or secondary graft failures. Complete response was achieved in 7 and 4 patients in strata I and II, respectively. Median follow-up for all patients was 30.7 months (mos) and was 99.8 mos for surviving patients. Median overall survival (OS) on strata I and II were 44.5 mos and 21.6 mos, respectively. Median PFS on strata I and II were 18.1 mos and 8.9 mos, respectively. In strata I, 5 patients developed Grade 2+ aGVHD and 8 developed extensive cGVHD. In strata II, 4 patients developed Grade 2+ aGVHD and 6 developed extensive cGVHD.

CONCLUSION

The TMI 900 cGy, FLU, and MEL conditioning regimen is considered safe as conditioning for allo-SCT and may warrant further investigation due to favorable response rates and survival; the conditioning regimen of FLU, MEL, and BTZ (0.7 mg/m2) is associated with unacceptable toxicities.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

Persistent Orofacial Pain Attendances at General Medical Practitioners

Patients with persistent orofacial pain (POFP) can go through complex care pathways to receive a diagnosis and management, which can negatively affect their pain. This study aimed to describe 44-y trends in attendances at Welsh medical practices for POFP and establish the number of attendances per patient and referrals associated with orofacial pain and factors that may predict whether a patient is referred. A retrospective observational study was completed using the nationwide Secure Anonymised Information Linkage Databank of visits to general medical practices in Wales (UK). Data were extracted using diagnostic codes ("Read codes"). Orofacial and migraine Read codes were extracted between 1974 and 2017. Data were analyzed using descriptive statistics and univariate and multivariable logistic regression. Over the 44-y period, there were 468,827 POFP and migraine diagnostic codes, accounting for 468,137 patient attendances, or 301,832 patients. The overall attendance rate was 4.22 attendances per 1,000 patient-years (95% confidence interval [CI], 4.21-4.23). The attendance rate increased over the study period. Almost one-third of patients (n = 92,192, 30.54%) attended more than once over the study period, and 15.83% attended more than once within a 12-mo period. There were 20,103 referral codes that were associated with 8,183 patients, with over half these patients being referred more than once. Odds of receiving a referral were highest in females (odds ratio [OR], 1.23; 95% CI, 1.17-1.29), in those living in rural locations (OR, 1.17; 95% CI, 1.12-1.22), and in the least deprived quintile (OR, 1.39; 95% CI, 1.29-1.48). Odds also increased with increasing age (OR, 1.03; 95% CI, 1.03-1.03). The increasing attendance may be explained by the increasing incidence of POFP within the population. These patients can attend on a repeated basis, and very few are referred, but when they are, this may occur multiple times; therefore, current care pathways could be improved.

The Edinburgh Claudication Questionnaire has poor diagnostic accuracy in people with intermittent claudication

BACKGROUND

The screening and diagnosis of intermittent claudication is a challenging process and often relies on the expertise of specialist vascular clinicians. We sought to investigate the diagnostic performance of the Edinburgh Claudication Questionnaire (ECQ) as a screening tool for referrals of suspected intermittent claudication from primary to secondary care.

METHOD

Prospectively, 100 referrals from primary care with a stated diagnosis or query regarding intermittent claudication were recruited. All participants who completed the ECQ, underwent an anklebrachial pressure index (ABPI) assessment and treadmill exercise testing. Outcomes of the ECQ were compared to clinical diagnoses of intermittent claudication.

RESULTS

The ECQ had a sensitivity of 46.8% (95% CI: 27-65%), specificity of 63.2% (95% CI: 43-82%) and accuracy of 53.0% (95% CI: 43-63%). The diagnostic performance was not changed by combining the ECQ with a positive ABPI or post-exercise ABPI outcome for PAD.

CONCLUSION

The ECQ had a poor diagnostic performance in this cohort. Considering the results found here and in other recent studies, the utility of the ECQ as a screening tool and epidemiological survey tool must be questioned. Novel, low-resource diagnostic tools are needed in this population.

1023 An Audit of The Prevalence of Frailty and The Impact on Surgical Management and Resource Use, For Vascular Inpatients Using the National Vascular Registry (NVR) Frailty Classifications

Aim

To determine if the NVR frailty score was being routinely collected on all relevant vascular patients on admission, identify the prevalence of frailty in vascular inpatients and determine if frailty was associated with a higher mortality and morbidity.

Method

A prospective audit of consecutive patients admitted onto the vascular ward who were eligible for inclusion on the NVR. Data was collected from electronic patient records and paper case notes between November 2019 and February 2020. The primary outcome was completeness of frailty assessment. Secondary outcomes were prevalence of frailty and mortality and morbidity associated with frailty score.

Results

Frailty status was documented in 65% of patients. 43% (28/65) were assessed to be frail. The 30-day mortality rate was 1.53% (1/65). 26.15% (17/65) had one or more complication. The commonest complications were graft occlusions, acute kidney injury, hospital acquired pneumonia and groin infections. 93.84% (61/65) were discharged home. There was no correlation between frailty and number of post-operative complications (p = 0.394), length of stay (p = 0.171) or mortality (p = 0.371).

Conclusions

This audit found frailty assessment is poorly assessed and the current NVR frailty classification did not correlate to increase mortality or morbidity in this patient cohort.

Pilot scale demonstration of a two-stage pretreatment and bioethanol fermentation process for cotton gin trash

A two-stage dilute acid and steam explosion (SE) pretreatment process was developed and evaluated at pilot scale for ethanol production from cotton gin trash (CGT). Optimal conditions for CGT processing were defined as 1:6 solids to liquids ratio with 9% H₂SO₄ wt. on solids at 180 °C for 15 min. during stage 1 with ensuing pressed fibres successively exposed to SE at 200 °C for 5 min during stage 2. SE fibres were highly acquiescent to enzyme hydrolysis (76%) in the presence of PEG 6000, yielding 381 g glucose kg^-1 fibre. Simultaneous saccharification and fermentation (SSF) trials validated the selected process option and additional fed-batch SSFs confirmed titres above the minimum 4% ww^-1 benchmark for economically viable distillation. The practicality of converting CGT to ethanol was demonstrated at pilot scale with titres above 4% ww^-1 and a conversion efficiency of 60% t^-1 dry GCT.

548 FRAILTY ANALYSIS ACROSS POPULATIONS: THE USE OF THE HOSPITAL FRAILTY RISK SCORE IN SPECIALISED SERVICES USING NHS NATIONAL DATA

Introduction

Frailty is increasingly used to risk stratify older people, but across specialised services there is no standardised approach. The aim of this study was to answer the question posed by NHS England to assess frailty could be measured and related to outcomes across Specialsed Services. The Hospital Frailty Risk Score (HFRS) was used and the data published in Age and Ageing in 2020.

Method

A retrospective cohort study was performed using the Secondary Uses Service (SUS) electronic database for people aged 75 or older admitted between April 2017 and March 2018. Based on HFRS, the populations were risk stratified into mild, moderate and severe frailty risk. The relationships with length of stay, readmission rate, mortality and some selected condition specific treatment complications were quantified using descriptive statistics.

Results

Frailty was differentially distributed across the specialties; around one-third had mild frailty; another third had moderate frailty and one-quarter severe frailty. Increasing frailty risk was associated with increased length of stay for the index admission, more days in hospital in the year following intervention and increased risk of dying in hospital. Severe frailty was a powerful discriminator of the risk of death; between 25 and 40% of those with severe frailty risk died at 30 months across all specialties.

Conclusions

This study demonstrates the first application of the HFRS to a national dataset to describe service outcomes and mortality for older people undergoing a range of specialised interventions. This information was used to identify those that might benefit from holistic assessment, aid prognostication, commissioning and service planning. It informed the promotion of quality improvement work in this area via the Specialised Clinical Frailty Network. By implementing the HFRS, changes in outcomes can be plotted across years to assess improvements, performance and benchmarking.

Safety, Tolerability and Pharmacokinetics of Single and Repeat Doses of Vixotrigine in Healthy Volunteers

Neuropathic pain affects ~ 6.9–10% of the general population and leads to loss of function, anxiety, depression, sleep disturbance, and impaired cognition. Here, we report the safety, tolerability, and pharmacokinetics of a voltage‐dependent and use‐dependent sodium channel blocker, vixotrigine, currently under investigation for the treatment of neuropathic pain conditions. The randomized, placebo‐controlled, phase I clinical trials were split into single ascending dose (SAD) and multiple ascending dose (MAD) studies. Healthy volunteers received oral vixotrigine as either single doses followed by a ≥ 7‐day washout period for up to 5 dosing sessions (SAD, n = 30), or repeat doses (once or twice daily) for 14 and 28 days (MAD, n = 51). Adverse events (AEs), maximum observed vixotrigine plasma concentration (C_max), area under the concentration‐time curve from predose to 24 hours postdose (AUC_0–24), time to C_max (T_max), and terminal half‐life (t1/2), among others, were assessed. Drug‐related AEs were reported in 47% and 53% of volunteers in the SAD and MAD studies, respectively, with dizziness as the most commonly reported drug‐related AE. SAD results showed that C_max and AUC increased with dose, T_max was 1–2 hours, and t_1/2 was ~ 11 hours. A twofold increase in accumulation was observed when vixotrigine was taken twice vs. once daily (MAD). Steady‐state was achieved from day 5 onward. These data indicate that oral vixotrigine is well‐tolerated when administered as single doses up to 825 mg and multiple doses up to 450 mg twice daily.

Presurgery exercise-based conditioning interventions (prehabilitation) in adults undergoing lower limb surgery for peripheral arterial disease

BACKGROUND

Lower limb peripheral arterial disease (PAD) is a type of cardiovascular disease where the blood vessels that carry the blood to the legs are hardened and narrowed. The most severe manifestation of PAD is critical limb ischaemia (CLI). This condition results in symptoms of intractable rest pain, non-healing wounds and ulceration, gangrene or both. PAD affects more than 200 million people worldwide and approximately 3% to 5% of people aged over 40 have PAD, rising to 18% in people over 70 years of age. Between 5% to 10% of symptomatic PAD patients will progress to CLI over a five-year period and the five year cumulative incidence rate for asymptomatic patients with PAD deteriorating to intermittent claudication is 7%, with 21% of these progressing to CLI. Treatment options include angioplasty, bypass or amputation of the limb, when life or limb is threatened. People with CLI have a high risk of mortality and morbidity. The mortality rates during a surgical admission are approximately 5%. Within one year of surgery, the mortality rate rises to 22%. Postoperative complications are as high as 30% and readmission rates vary between 7% to 18% in people with CLI. Despite recent advances in surgical technology, anaesthesia and perioperative care, a proportion of surgical patients have a suboptimal recovery. Presurgery conditioning (prehabilitation) is a multimodal conditioning intervention carried out prior to surgery using a combination of exercise, with or without nutritional or psychological interventions, or both. The use of prehabilitation is gaining momentum, particularly in elderly patients undergoing surgery and patients undergoing colorectal cancer surgery, as a means of optimising fitness to improve the prognosis for people undergoing the physiological stress of surgery. People with PAD are characterised by poor mobility and physical function and have a lower level of fitness as a result of disease progression. Therefore, prehabilitation may be an opportunity to improve their recovery following surgery. However, as multimodal prehabilitation requires considerable resources, it is important to assess whether it is superior to usual care. This review aimed to compare prehabilitation with usual care (defined as a preoperative assessment, including blood and urine tests). The key outcomes were postoperative complications, mortality and readmissions within 30 days of the surgical procedure, and one-year survival rates.

OBJECTIVES

To assess the effectiveness of prehabilitation (preoperative exercise, either alone or in combination with nutritional or psychological interventions, or both) on postoperative outcomes in adults with PAD undergoing open lower limb surgery.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials register to 25 September 2019.

SELECTION CRITERIA

We considered all published and unpublished randomised controlled trials (RCTs) comparing presurgery interventions and usual care. Primary outcomes were postoperative complications, mortality and readmission to hospital within 30 days of the surgical procedure.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed all records identified by the searches conducted by the Cochrane Vascular Information Specialist. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We found no RCTs that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We found no RCTs conducted to determine the effects of prehabilitation on mortality or other postoperative outcomes when compared to usual care for patients with PAD. As a consequence, we were unable to provide any evidence to guide the treatment of patients with PAD undergoing surgery. To perform a randomised controlled trial of presurgery conditioning would be challenging but trials are warranted to provide solid evidence on this topic.

Discovery of Vixotrigine: A Novel Use-Dependent Sodium Channel Blocker for the Treatment of Trigeminal Neuralgia

Drugs that block voltage-gated sodium channels (NaVs) have utility in treating conditions including pain, epilepsy, and cardiac arrhythmias and as anesthetics (Lancet Neurol.20109413424; Expert Opin. Ther. Pat.201020755779). The identification of compounds with improved efficacy and safety is a key aim for the discovery of improved NaV blocking drugs (Comprehensive Medicinal Chemistry III; (Elsevier, 2017; pp 131-175). We report the identification of a novel class of brain penetrant and voltage-gated sodium channel blockers, leading to the discovery of vixotrigine, a use-dependent sodium channel blocker with activity in in vivo models of pain. Vixotrigine has excellent physiocochemical properties for drug development, and both preclinical and clinical data support a safety profile suitable for potential use in neuropathic pain and other conditions. It has shown efficacy in a Phase II study for pain associated with trigeminal neuralgia.

Inactivation of the gene encoding the cationic antimicrobial peptide resistance factor MprF increases biofilm formation but reduces invasiveness of Listeria monocytogenes

AIMS

To understand the genetics involved in surface attachment and biofilm formation of Listeria monocytogenes.

METHODS AND RESULTS

An in vitro screen of a Himar1 transposon library of L. monocytogenes strain 15G01 identified three transposants that produced significantly different biofilm levels when compared to the wild-type strain; two mutants exhibited enhanced biofilm formation and one produced less biofilm biomass than the wild-type. The mutant 15G01 mprF::Himar1, which had a transposon insertion in the mprF gene, was selected for further analysis. The mutant produced a more densely populated biofilm on solid surfaces such as stainless steel and polystyrene, as determined using scanning electron and light microscopy. The 15G01 mprF::Himar1 mutant remained viable in biofilms, but showed an increase in sensitivity to the cationic antimicrobial gallidermin. The mutant also displayed reduced invasiveness in CaCo-2 intestinal cells, suggesting virulence properties are compromised by the inactivation of mprF.

CONCLUSIONS

Biofilm formation and gallidermin resistance of L. monocytogenes is influenced by mprF, but this trait is associated with a compromise in invasiveness.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presence of pathogenic microorganisms in the food processing environment can cause a significant problem, especially when these microorganisms are established as biofilms. This study shows that the inactivation of the mprF gene results in enhanced biofilm formation and abiotic surface attachment of L. monocytogenes.

Design of Phase 3 Studies Evaluating Vixotrigine for Treatment of Trigeminal Neuralgia

Purpose

Vixotrigine (BIIB074) is a voltage- and use-dependent sodium channel blocker. These studies will evaluate the efficacy and safety of vixotrigine in treating pain experienced by patients with trigeminal neuralgia (TN) using enriched enrollment randomized withdrawal trial designs.

Patients and Methods

Two double-blind randomized withdrawal studies are planned to evaluate the efficacy and safety of vixotrigine compared with placebo in participants with TN (NCT03070132 and NCT03637387). Participant criteria include ≥18 years old who have classical, purely paroxysmal TN diagnosed ≥3 months prior to study entry, who experience ≥3 paroxysms of pain/day. The two studies will include a screening period, 7-day run-in period, a 4- or 6-week single-dose-blind dose-optimization period (Study 1) or 4-week open-label period (Study 2), and 14-week double-blind period. Participants will receive vixotrigine 150 mg orally three times daily in the dose-optimization and open-label periods. The primary endpoint of both studies is the proportion of participants classified as responders at Week 12 of the double-blind period. Secondary endpoints include safety measures, quality of life, and evaluation of vixotrigine population pharmacokinetics.

Conclusion

There is a need for an effective, well-tolerated, noninvasive treatment for the neuropathic pain associated with TN. The proposed studies will evaluate the efficacy and safety of vixotrigine in treating pain experienced by patients with TN.

Evaluation of the Pharmacokinetic Interaction Between the Voltage- and Use-Dependent Nav1.7 Channel Blocker Vixotrigine and Carbamazepine in Healthy Volunteers

Vixotrigine is a voltage- and use-dependent Nav1.7 channel blocker under investigation for the treatment of peripheral neuropathic pain conditions, including trigeminal neuralgia. Vixotrigine is metabolized primarily via uridine diphosphate-glucuronosyltransferases (UGTs). Carbamazepine, a UGT and cytochrome P450 3A4 inducer, is a first-line treatment for trigeminal neuralgia. We conducted a double-blind, randomized, placebo-controlled, parallel-group, single-center phase 1 study to investigate the impact of coadministering vixotrigine and carbamazepine on their respective pharmacokinetics (PK) in healthy volunteers, the safety and tolerability of combined treatment, and PK recovery of vixotrigine following carbamazepine discontinuation. Randomly assigned treatments were carbamazepine (100 mg twice a day, days 1-3 and 200 mg twice a day, days 4-21) or placebo on days 1 to 21. All volunteers received vixotrigine 150 mg 3 times a day on days 16 to 28. At prespecified times, whole-blood samples were collected for PK assessment. Statistical analyses were performed on the log-transformed PK parameters area under the concentration-time curve within a dosing interval (AUC_0-tau ) and maximum observed concentration (C_max ) for vixotrigine, carbamazepine, and metabolites. Vixotrigine AUC_0-tau and C_max were reduced by 31.6% and 26.3%, respectively, when coadministered with carbamazepine compared with placebo. Seven days after carbamazepine discontinuation, vixotrigine AUC_0-tau and C_max remained 24.5% and 21.4% lower compared with placebo. Carbamazepine AUC_0-tau and C_max were <10% lower when coadministered with vixotrigine compared on days 15 and 21. Vixotrigine/carbamazepine coadministration was well tolerated. These results suggest that vixotrigine does not have an effect on carbamazepine PK, and although carbamazepine has an effect on the exposure of vixotrigine, the effect is not considered clinically relevant.

The effect of phosphate on the heat resistance of spores of dairy isolates of Geobacillus stearothermophilus

In this study, we show that phosphate decreases the spore heat resistance by accelerating the rate of loss of cations from spores. Heat resistance of spores of Geobacillus stearothermophilus A1, D1, P3 and ATCC 12980 were determined in distilled water containing varying concentrations (0.1, 1 and 2% w/v) of di‑sodium phosphate. The average decimal reduction times (D value) for strains A1, D1, P3 and ATCC 12980 in distilled water were 5.8, 6.8, 5.7 and 9 min at 110 °C respectively. On the addition of 0.1, 1 and 2% w/v of di‑sodium phosphate, the average D₁₁₀ values of all the strains in distilled water were lowered by 50, 61 and 70% respectively. Addition of 0.05% w/v of Na-EDTA to distilled water resulted in lowering of the average D₁₁₀ value of all the strains by 55%. Heat resistance of spores of A1, D1, P3 and ATCC 12980 was found to be associated with the Dipicolinic Acid (DPA) content whose concentrations were 0.25, 0.30, 0.27 and 1.6 pg per spore respectively. Analysis by atomic absorption spectroscopy revealed that the phosphate present in the heating medium causes excess release of calcium from spores with 2% w/v phosphate being highly effective, thus confirming the chelating effect of phosphate. This study provides insight into the heat resistance and the increased heat sensitivity of spores of G. stearothermophilus A1, D1 and P3 in the presence of phosphate, which can be used in the design of Cleaning in Place (CIP) systems involving phosphate based cleaning agents to combat biofilms and spores in the dairy industry.

Is virtual clinic follow-up of hip and knee joint replacement acceptable to patients and clinicians? A sequential mixed methods evaluation

Objective

To evaluate the acceptability to key stake holders of a newly introduced virtual clinic follow-up pathway for hip and knee joint replacement.

Design

A service evaluation comprising a questionnaire sent electronically to 115 patients and interviews with 10 individuals.

Setting

A newly introduced virtual clinic follow-up pathway for hip and knee replacement patients in a district general hospital.

Participants

The electronic questionnaire was distributed to all patients treated under the virtual clinic service over a 5-month period (n=115). Purposive sampling from volunteers among respondents, leading to semi-structured interviews with eight patients. Two orthopaedic consultants were also interviewed.

Intervention

Consultant review of web-based patient reported outcome measures and digital radiographs, with feedback to patients via letter, replacing face-to-face outpatient appointments for the follow-up of hip and knee joint replacement.

Results

The response rate to the questionnaire was 40%. 44% indicated they would prefer a virtual appointment over a face-to-face consultation in future. The most common word in the free text comments was ‘good’ (n=107).

Seven main themes were identified from the patient interviews: patient understanding and expectations, patient confidence, patient voice, managing deterioration of condition, patient benefit, patient satisfaction using technology and navigating the website.

Two main themes were identified from the staff interviews: the adapting patient pathway and project management.

Combined analysis elucidated that patients who were doing well liked the ‘click and go’ approach but those with problems were concerned about how to report these and were therefore less satisfied.

Conclusion

The virtual clinic process appears to be well accepted by both patients and clinicians. However, appropriate patient selection and clear pathways of communication to address patient concerns are pivotal to success.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Challenges recruiting to a proof-of-concept pharmaceutical trial for a rare disease: the trigeminal neuralgia experience

Background

This study aimed to describe recruitment challenges encountered during a phase IIa study of vixotrigine, a state and use-dependent Nav1.7 channel blocker, in individuals with trigeminal neuralgia.

Methods

This was an international, multicenter, placebo-controlled, randomized withdrawal study that included a 7-day run-in period, a 21-day open-label phase, and a 28-day double-blind phase in which patients (planned n = 30) were randomized to vixotrigine or placebo. Before recruitment, all antiepileptic drugs had to be stopped, except for gabapentin or pregabalin. After the trial, patients returned to their original medications. Patient recruitment was expanded beyond the original five planned (core) centers in order to meet target enrollment (total recruiting sites N = 25). Core sites contributed data related to patient identification for study participation (prescreening data). Data related to screening failures and study withdrawal were also analyzed using descriptive statistics.

Results

Approximately half (322/636; 50.6%) of the patients who were prescreened at core sites were considered eligible for the study and 56/322 (17.4%) were screened. Of those considered eligible, 26/322 (8.1%) enrolled in the study and 6/322 (1.9%) completed the study. In total, 125 patients were screened across all study sites and 67/125 (53.6%) were enrolled. At prescreening, reasons for noneligibility varied by site and were most commonly diagnosis change (78/314; 24.8%), age > 80 years (75/314; 23.9%), language/distance/mobility (61/314; 19.4%), and noncardiac medical problems (53/314; 16.9%). At screening, frequently cited reasons for noneligibility included failure based on electrocardiogram, insufficient pain, and diagnosis change.

Conclusions

Factors contributing to recruitment challenges encountered in this study included diagnosis changes, anxiety over treatment changes, and issues relating to distance, language, and mobility. Wherever possible, future studies should be designed to address these challenges.

Trial registration

ClinicalTrials.gov, NCT01540630.

EudraCT, 2010-023963-16. 07 Aug 2015.

Home-based exercise programmes for individuals with intermittent claudication: A protocol for an updated systematic review and meta-analysis

Background

The aim of this updated review is to consider the evidence base for the effectiveness of home-based exercise programmes as a treatment option for improving walking distance in patients with intermittent claudication.

Methods

The Medline, EMBASE, CINAHL, PEDro and Cochrane CENTRAL databases will be searched for terms including 'intermittent claudication', 'peripheral arterial disease', 'home-based exercise' and 'home-based walking'. No date restrictions will be used but only articles in the English language will be included. Both randomised and non-randomised trials of home-based exercise programmes versus a comparator arm will be included, and a meta-analysis using only the randomised controlled trials will be attempted if the assumptions of heterogeneity are met. Data extraction will include study details, sample description, intervention description, length of follow-up and outcomes measures. The primary outcome measure is objectively measured maximal walking distance or time, with secondary outcome measures including pain-free walking distance or time, changes in physical activity and quality of life. We will also provide a narrative description of the effective components of a home-based exercise intervention which can aid future recommendations.

Conclusion

Overall, this proposed review and meta-analysis aims provide a comprehensive and complete overview of the evidence base for home-based exercise programmes, which can aid clinicians in the management of their patients.

Trial of intraoperative cell salvage versus transfusion in ovarian cancer (TIC TOC): protocol for a randomised controlled feasibility study

INTRODUCTION

Ovarian cancer is the leading cause of death from gynaecological cancer, with more than 7000 new cases registered in the UK in 2014. In patients suitable for surgery, the National Institute of Health and Care Excellence guidance for treatment recommends surgical resection of all macroscopic tumour, followed by chemotherapy. The surgical procedure can be extensive and associated with substantial blood loss which is conventionally replaced with a donor blood transfusion. While often necessary and lifesaving, the use of donor blood is associated with increased risks of complications and adverse surgical outcomes. Intraoperative cell salvage (ICS) is a blood conservation strategy in which red cells collected from blood lost during surgery are returned to the patient thus minimising the use of donor blood. This is the protocol for a feasibility randomised controlled trial with an embedded qualitative study and feasibility economic evaluation. If feasible, a later definitive trial will test the effectiveness and cost-effectiveness of ICS reinfusion versus donor blood transfusion in ovarian cancer surgery.

METHODS AND ANALYSIS

Sixty adult women scheduled for primary or interval ovarian cancer surgery at participating UK National Health Service Trusts will be recruited and individually randomised in a 1:1 ratio to receive ICS reinfusion or donor blood (as required) during surgery. Participants will be followed up by telephone at 30 days postoperatively for adverse events monitoring and by postal questionnaire at 6 weeks and 3 monthly thereafter, to capture quality of life and resource use data. Qualitative interviews will capture participants' and clinicians' experiences of the study.

ETHICS AND DISSEMINATION

This study has been granted ethical approval by the South West-Exeter Research Ethics Committee (ref: 16/SW/0256). Results will be disseminated via peer-reviewed publications and will inform the design of a larger trial.

TRIAL REGISTRATION NUMBER

ISRCTN19517317.

Low-Dose Anti-Thymocyte Globulin (ATG) Preserves β-Cell Function and Improves HbA1c in New-Onset Type 1 Diabetes

OBJECTIVE

A pilot study suggested that combination therapy with low-dose anti-thymocyte globulin (ATG) and pegylated granulocyte colony-stimulating factor (GCSF) preserves C-peptide in established type 1 diabetes (T1D) (duration 4 months to 2 years). We hypothesized that 1) low-dose ATG/GCSF or 2) low-dose ATG alone would slow the decline of β-cell function in patients with new-onset T1D (duration <100 days).

RESEARCH DESIGN AND METHODS

A three-arm, randomized, double-masked, placebo-controlled trial was performed by the Type 1 Diabetes TrialNet Study Group in 89 subjects: 29 subjects randomized to ATG (2.5 mg/kg intravenously) followed by pegylated GCSF (6 mg subcutaneously every 2 weeks for 6 doses), 29 to ATG alone (2.5 mg/kg), and 31 to placebo. The primary end point was mean area under the curve (AUC) C-peptide during a 2-h mixed-meal tolerance test 1 year after initiation of therapy. Significance was defined as one-sided P value < 0.025.

RESULTS

The 1-year mean AUC C-peptide was significantly higher in subjects treated with ATG (0.646 nmol/L) versus placebo (0.406 nmol/L) (P = 0.0003) but not in those treated with ATG/GCSF (0.528 nmol/L) versus placebo (P = 0.031). HbA_1c was significantly reduced at 1 year in subjects treated with ATG and ATG/GCSF, P = 0.002 and 0.011, respectively.

CONCLUSIONS

Low-dose ATG slowed decline of C-peptide and reduced HbA_1c in new-onset T1D. Addition of GCSF did not enhance C-peptide preservation afforded by low-dose ATG. Future studies should be considered to determine whether low-dose ATG alone or in combination with other agents may prevent or delay the onset of the disease.