Digitised remote delivery of simulation in psychiatry during the pandemic and for the future

Introduction

Surrey and Borders NHS Foundation Trust’s AVATr (Augmented Virtual-reality Avatar in Training) is a unique ground-breaking Virtual Patient simulation system, which uses the Xenodu platform to train learners in essential clinical and complex communication skills. Over 30 patient scenarios have been developed after identifying learner-specific development needs, including exploration of overt psychosis, assessment of capacity, sharing bad news, and neglect in care home residents.

During the session, the trainee is projected on to a large screen, using a camera and video special effects, which results in a life-like interaction with the Virtual Patient. Trainees can view themselves interacting with the Virtual Patient in real-time, from a unique ’out-of-body’ perspective, immersed in a customdesigned interactive virtual environment. This is different to a first-person perspective used in virtual or augmented-reality systems in several clinical specialties. During the COVID-19 pandemic, we evolved the AVATr model to remote or hybrid sessions, where simulations were digitally enhanced, and have been run through Microsoft Teams. The simulation facilitator is connected to a multi-user video call, enabling the Virtual Patient to be projected as an attendee using Microsoft Teams.

Objectives

To evaluate the feedback from Doctors in training taking part on the education sessions.

Methods

We collected qualitiative and quanttaive infromation from participants after the teaching session.

Results

We received strongly positive reults in all parameters measured. the presenters will show a detailed breakdoen in the session.

Conclusions

The digitalised delivery of the virtual patient simulation, has been pivotal in limiting interruptions to communication skills training in mental health.

Disclosure

The NHS trust has co produced the simulation platform with a private software firm Xenadu Virtual Environments

POS1227 TIME BETWEEN SECOND AND THIRD DOSES INFLUENCES RESPONSE TO COVID-19 VACCINE IN AUTO-IMMUNE DISEASE PATIENTS TREATED WITH RITUXIMAB WITHOUT RESPONSE TO TWO DOSES

Background

It is now well established that patients treated with rituximab (RTX) for auto-immune disease (AID) have a diminished antibody response to COVID-19 vaccines after two doses. Optimizing antibody response is a key objective in this population. To achieve this goal, a 3rd booster dose may be considered.

Objectives

Focusing on the population of AID patients treated with RTX without any antibody response after two doses we sought to explore how these patients could respond to a 3rd dose and identify factors of response.

Methods

We performed a French retrospective bicentric observational trial which is a follow up of previously published work (1). We included consecutive patients treated with RTX that were non-responders regarding their anti-Spike antibody (anti-S) status at least one month after the second dose of COVID-19 vaccination. Patients were included between March and October 2021. All patients then received a third dose according to local guidelines and had an anti-S measurement at least one month after the third dose. Some patients without response to a third dose had a fourth dose. Anti-S were measured in serum with various kits, but all results were in BAU/mL with upper quantification limit at 243. Patients with anti-S above 49 BAU/mL, which has been demonstrated to be the threshold associated with detectable neutralizing response were considered as responders (1).

Results

60 patients treated with RTX without response to 2 doses (Anti-S Ab < 49 BAU/mL) were included in the study. 9/60 (15%) patients responded to the 3rd vaccine dose with anti-S > 49BAU/ml.

Responders and non-responders had similar demographic characteristics (Table 1). There was a positive correlation between anti-S Ab levels after dose 3 and time between 2nd and 3rd doses (r=0,41 p=0,001) (Figure 1). Nevertheless, the median time between 2nd and 3rd doses was numerically but not significantly higher in responders than in non-responders (129 vs 80 days, p=0.30). There was no correlation between anti-S levels after the third dose and the time between the last RTX infusion and the third vaccine dose. There was a trend towards more patients with methotrexate co-medication in the non-responder group 31/51 (61%) vs 3/9 (33%) in the responder group (p=0,15). Seven non-responder patients after the 3rd dose received a 4th dose and 4 (57%) responded.

Table 1.

Characteristics of patients without response after the second dose of vaccine treated with Rituximab for auto-immune diseases according to their seroconversion status after the third dose.

Non responders (n=51)Responders (n=9)pAge, median (min-max)61 (17-85)58 (36-78)0,33Female sex n (%)42 (82)6 (67)0,36Underlying disease n (%) Rheumatoid Arthritis36 (69)5 (56)0,46 Other auto-immune disease16 (31)4 (44)Rituximab treatmentReceived a RTX infusion between dose 2 and 3 n (%)14(27)3(33)0,70Time between the last RTX infusion and the 3rd dose of vaccine in days median (min-max)162 (1-687)187 (79-959)0,16Previous number of RTX injections, median (min-max)7 (0-34)6 (1-22)0,58Vaccination schemeInterval between 2nd and 3rd vaccine dose in days, median (min-max)80 (23-287)129 (24-220)0,30Less than 3 months between 2nd and 3rd vaccine dose n (%)27(53)2(22)0,14Co-medicationsPatients on steroids n (%)20(40)5 (37,5)0,99Prednisone equivalent dose per day in mg median (min-max)5(2-25)5(5-10)0,48Figure 1.

Correlation between anti- spike Ab levels after the third dose and time in days between doses 2 and 3.

Conclusion

A third vaccine dose of COVID-19 vaccine leads to only 15% of response in previously non-responding RTX treated AID patients. A longer time between 2nd and 3rd doses might positively influences response to a 3rd COVID-19 vaccine. Finally exploratory findings show that a fourth dose could be useful to obtain response non-responders.

References

[1]Bitoun S, Henry J, Desjardins D, et al. Rituximab impairs B-cell response but not T-cell response to COVID-19 vaccine in auto-immune diseases. Arthritis Rheumatol Hoboken NJ Published Online First: 28 December 2021.

Disclosure of Interests

None declared

POS0711 TOLERANCE AND EFFICACY OF TARGETED THERAPIES PRESCRIBED FOR OFF-LABEL INDICATIONS IN REFRACTORY SYSTEMIC AUTOIMMUNE DISEASES: DATA OF THE FIRST 100 PATIENTS ENROLLED IN THE TATA REGISTRY (TARGETED THERAPY IN AUTOIMMUNE DISEASES)

Background

The low prevalence of systemic autoimmune diseases and the diversity of their clinical manifestations make complex to conduct randomised clinical trials to assess the potential efficacy of targeted treatments.

Objectives

To assess the tolerance and efficacy of targeted therapies prescribed off-label in refractory autoimmune diseases.

Methods

The TATA registry (TArgeted Therapy in Autoimmune Diseases) is a prospective, observational, national and independent cohort follow-up. The inclusion criteria in the registry are as follows: age > 18 years; rare systemic autoimmune disease (systemic lupus erythematosus, Sjögren’s syndrome, systemic scleroderma, inflammatory myopathy, vasculitis) or other refractory rheumatism treated with off-label drugs started after 1st January 2019.

Results

Hundred (100) patients (79 females) were enrolled. The median age was 52.5 years [49;56], the median disease duration before enrolment was 5 years [3;7]. The targeted therapies at enrolment were as follows: JAK/STAT inhibitors (44%), anti-IL6R (22%), anti-IL12/23, anti-IL23 and anti-IL17 (9%), anti-BAFF (5%), abatacept (5%), other targeted treatments (9%), and combination of targeted treatments (6%). 73% of patients were receiving corticosteroid therapy at enrolment (median dose 10 mg/day). The current median follow-up time is 9 months [8;10].

Safety: 11 serious infections (incidence rate of 14.8 /100 patient-years) and 1 cancer (1.3 cancers/100 patient-years) were observed. Two patients died from severe COVID-19 (2.7 deaths/100 patient-years).

Efficacy: The targeted treatment was considered effective by the clinician in 56% of patients and allowed in responders a median reduction of oral corticosteroids of 15 [9-21] mg/day.

Conclusion

These initial results of the TATA registry confirm the diversity of targeted treatments prescribed off-label in refractory autoimmune diseases and their corticosteroid-sparing effect when effective. Tolerance was acceptable in these refractory patients with a long history of treatment with immunosuppressive drugs.

References

[1]B. Terrier et al., Safety and efficacy of rituximab in systemic lupus erythematosus: results from 136 patients from the French AutoImmunity and Rituximab registry. Arthritis Rheum 62, 2458-2466 (2010).

[2]J. E. Gottenberg et al., Efficacy of rituximab in systemic manifestations of primary Sjogren’s syndrome: results in 78 patients of the AutoImmune and Rituximab registry. Ann Rheum Dis 72, 1026-1031 (2013).

[3]J. E. Gottenberg et al., Risk factors for severe infections in patients with rheumatoid arthritis treated with rituximab in the autoimmunity and rituximab registry. Arthritis Rheum 62, 2625-2632 (2010).

[4]F. R. S. S. S. C. I. consortium, contributors, Severity of COVID-19 and survival in patients with rheumatic and inflammatory diseases: data from the French RMD COVID-19 cohort of 694 patients. Ann Rheum Dis, (2020).

[5]R. Felten et al., B-cell targeted therapy is associated with severe COVID-19 among patients with inflammatory arthritides: a 1-year multicentre study in 1116 successive patients receiving intravenous biologics. Ann Rheum Dis 81, 143-145 (2022).

[6]D. J. Wallace et al., Baricitinib for systemic lupus erythematosus: a double-blind, randomised, placebo-controlled, phase 2 trial. Lancet 392, 222-231 (2018).

[7]J. J. Paik et al., Study of Tofacitinib in Refractory Dermatomyositis: An Open-Label Pilot Study of Ten Patients. Arthritis Rheumatol 73, 858-865 (2021).

[8]S. Cole et al., Integrative analysis reveals CD38 as a therapeutic target for plasma cell-rich pre-disease and established rheumatoid arthritis and systemic lupus erythematosus. Arthritis Res Ther 20, 85 (2018).

[9]S. J. Bowman et al., Safety and efficacy of subcutaneous ianalumab (VAY736) in patients with primary Sjogren’s syndrome: a randomised, double-blind, placebo-controlled, phase 2b dose-finding trial. Lancet 399, 161-171 (2022).

Acknowledgements

French networks (FAI2R, CRI, IMIDIATE, SFR, SNFMI) focused on rare systemic autoimmune diseases contributed this work by the contribution of network-affiliated physicians.

Disclosure of Interests

Jacques-Eric Gottenberg Consultant of: Abbvie, BMS, Gilead, Galapagos, Novartis, Lilly Roche Chugai, Sanofi, Janssen, Pfizer, Grant/research support from: BMS.

Lilly and Pfizer for this register (with no access to data)., Aurore Chaudier: None declared, Yves Allenbach: None declared, Arsene Mekinian: None declared, Zahir Amoura: None declared, Patrice cacoub: None declared, Divi Cornec: None declared, Eric Hachulla: None declared, Pierre Quartier: None declared, isabelle melki: None declared, Christophe Richez: None declared, Raphaèle Seror: None declared, Benjamin Terrier: None declared, Valerie Devauchelle-Pensec: None declared, Julien Henry: None declared, MARC GATFOSSE: None declared, LAURENCE BOUILLET: None declared, Emeline GAIGNEUX: None declared, Vincent ANDRE: None declared, Gildas BAULIER: None declared, Aurélie SAUNIER: None declared, Marie Desmurs: None declared, Antoine POULET: None declared, Mathieu ETE: None declared, Marie-Elise Truchetet: None declared, Martin Michaud: None declared, Claire Larroche: None declared, AZEDDINE DELLAL: None declared, Amelie LEURS: None declared, Sebastien Ottaviani: None declared, Hubert NIELLY: None declared, Guillaume VIAL: None declared, Roland JAUSSAUD: None declared, Benedicte ROUVIERE: None declared, Pierre-Yves JEANDEL: None declared, Aurelien GUFFROY: None declared, Anne-Sophie Korganow: None declared, Mathieu JOUVRAY: None declared, alain meyer: None declared, Emmanuel Chatelus: None declared, Christelle Sordet: None declared, Renaud FELTEN: None declared, Jean Sibilia: None declared, Samira AHMED YAHIA: None declared, Jean François Kleinmann: None declared, Xavier Mariette Consultant of: BMS, Galapagos, GSK, Janssen, Novartis, Pfizer, Sanofi, UCB

POS0818 TREATMENT OF POLYMYALGIA RHEUMATICA WITH TOCILIZUMAB: RESULTS OF AN OBSERVATIONAL RETROSPECTIVE MULTICENTER STUDY

Background:

In 2017, TOCILIZUMAB (TCZ) obtained marketing authorization for treatment of giant cell arteritis (GCA); however, this doesn’t extend to polymyalgia rheumatica (PMR) therapy. Based on efficacy data for TCZ in GCA, TCZ is sometimes used as a glucocorticoid (GC) sparing agent when PMR is GC dependent or when a rapid steroid withdraw is needed. Currently, there are no available recommendations on the use of this therapeutic class in for this particular indication.

Objectives:

Here, we present the results of an observational French multicentric study of patients with PMR treated with TCZ.

Methods:

Thirteen medical centers were included in this study. The data was collected retrospectively between 2015 and 2020. The minimum duration of treatment was 3 months. Patients were included when receiving TCZ for isolated PMR or associated with a non-active GCA (asymptomatic, no vascular fixation on PET scanner).

Results:

Overall, 34 patients were included (24 women; mean age 70.1 years (+/-10.3)). At TCZ introduction, patients had been treated with GC for a mean duration of 27,9 months (+/-25.9) and the mean GC dose was 16,8mg/d (+/-10). Fifteen patients (44%) had one or more complications from GC therapy. Another immunosuppressant was added before TCZ treatment for 25 (74%); mostly METHOTREXATE (24/25).

TCZ was initiated intravenously at 8mg/kg every 4 weeks for 27 patients (79%) and subcutaneously at 162mg/week for 7 patients (21%).

The reasons for TCZ introduction included GC dependence (n=30, 88%), and necessity of quick GC sparing (n=4 patients,12%).

Of all patients, 76% (26 patients) had stopped GC treatment definitively, with a mean time of 9,4 (0-32) months.

The mean TCZ treatment period was 19,2 months (3-66). Fifteen patients (44%) permanently stopped TCZ at the end of the observation period (8 prolonged remissions;1 myocardial infarction; 1 cutaneous lymphoma; 1 primary failure, 3 lost to follow up).

Eighteen patients (60%) benefited from an attempted tapering of TCZ (infusion spacing or dose reduction), 6 attempts (1/3) led to a relapse. 1/2 patients had side effects mostly benign (cytopenia n=6, infections n=5).

Conclusion:

This is the largest cohort presenting results of the use of TCZ in PMR. Despite the small number of participants, our study suggests TCZ is effective as a GC sparing agent in PMR. As there are no official recommendations of use, indications for TCZ use within this population are no defined. Randomized Controlled Trial would be beneficial to validate these first results.

References:

[1]Toussirot, « Biothérapies, pseudo- polyarthrite rhizomélique et artérite à cellules géantes État des lieux en 2018 ».

[2]Devauchelle-Pensec et al., « Efficacy of First-Line Tocilizumab Therapy in Early Polymyalgia Rheumatica ».

[3]Genovese et al., « Longterm Safety and Efficacy of Tocilizumab in Patients with Rheumatoid Arthritis ».

[4]Stone et al., « Trial of Tocilizumab in Giant-Cell Arteritis ».

Disclosure of Interests:

None declared

LB0002 COVID-19 VACCINE SAFETY IN PATIENTS WITH RHEUMATIC AND MUSCULOSKELETAL DISEASE

Background:

The consequences of the COVID-19 outbreak are unprecedented and have been felt by everyone around the world, including people with rheumatic and musculoskeletal diseases (RMDs). With the development of vaccines, the future is becoming brighter. Vaccines are a key pillar of public health and have been proven to prevent many serious diseases. However, vaccination also raises questions, especially for patients with inflammatory RMDs and/or treated with drugs that influence their immune system.

Objectives:

Our aim was to collect safety data among RMD patients receiving COVID-19 vaccines.

Methods:

The EULAR COVID-19 Vaccination (COVAX) Registry is an observational registry launched on 5 February 2021. Data are entered voluntarily by clinicians or associated healthcare staff; patients are eligible for inclusion if they have an RMD and have been vaccinated against SARS-CoV-2. Descriptive statistics are presented.

Results:

As of 27 April 2021, 1519 patients were reported to the registry. The majority were female (68%) and above the age of 60 (57%). Mean age was 63 years (SD 16), ranging from 15 to 97 years. A total of 28 countries contributed to the registry, with France (60%) and Italy (13%) as the highest contributors. The majority (91%) had inflammatory RMDs. Inflammatory joint diseases accounted for 51% of cases, connective tissue diseases 19%, vasculitis 16%, other immune mediated inflammatory diseases 4%, and non-inflammatory/mechanical RMDs 9%. The most frequent individual diagnoses were rheumatoid arthritis (30%), axial spondyloarthritis (8%), psoriatic arthritis (8%), systemic lupus erythematosus (SLE, 7%) and polymyalgia rheumatica (6%). At the time of vaccination, 45% were taking conventional synthetic DMARDs, 36% biological DMARDs, 31% systemic glucocorticoids, 6% other immunosuppressants (azathioprine; mycophenolate; cyclosporine; cyclophosphamide; tacrolimus), and 3% targeted synthetic DMARDs. The most frequent individual DMARDs were methotrexate (29%), TNF-inhibitors (18%), antimalarials (10%) and rituximab (6%). The vaccines administered were: 78% Pfizer, 16% AstraZeneca, 5% Moderna and 1% other/unknown; 66% of cases received two doses and 34% one dose. Mean time from 1st and 2nd dose to case report was 41 days (SD 26) and 26 days (SD 23), respectively. COVID-19 diagnosis after vaccination was reported in 1% (18/1519) of cases. Mean time from first vaccination until COVID-19 diagnosis was 24 days (SD 17). Disease flares were reported by 5% (73/1375) of patients with inflammatory RMDs, with 1.2% (17/1375) classified as severe flares. Mean time from closest vaccination date to inflammatory RMD flare was 5 days (SD 5). The most common flare types were arthritis (35/1375=2.5%), arthralgia (29/1375=2.1%), cutaneous flare (11/1375=0.8%) and increase in fatigue (11/1375=0.8%). Potential vaccine side effects were reported by 31% of patients (467/1519). The majority were typical early adverse events within 7 days of vaccination, namely pain at the site of injection (281/1519=19%), fatigue (171/1519=11%) and headache (103/1519=7%). Organ/system adverse events were reported by 2% (33/1519) but only 0.1% (2/1519) reported severe adverse events, namely a case of hemiparesis in a patient with systemic sclerosis/SLE overlap syndrome (ongoing at the time of reporting), and a case of giant cell arteritis in a patient with osteoarthritis (recovered/resolved without sequelae).

Conclusion:

The safety profiles for COVID-19 vaccines in RMD patients was reassuring. Most adverse events were the same as in the general population, they were non-serious and involved short term local and systemic symptoms. The overwhelming majority of patients tolerated their vaccination well with rare reports of inflammatory RMD flare (5%; 1.2% severe) and very rare reports of severe adverse events (0.1%). These initial findings should provide reassurance to rheumatologists and vaccine recipients, and promote confidence in COVID-19 vaccine safety in RMD patients, namely those with inflammatory RMDs and/or taking treatments that influence their immune system.

Acknowledgements:

EULAR COVID-19 Task Force; European Reference Network on rare and Complex Connective Tissue and Musculoskeletal Diseases; European Reference Network on Rare Immunodeficiency, Autoinflammatory and Autoimmune Diseases Network; all rheumatologists contributing to the EULAR COVAX Registry.

Disclosure of Interests:

Pedro M Machado Consultant of: Abbvie, BMS, Celgene, Eli Lilly, Janssen, MSD, Novartis, Orphazyme, Pfizer, Roche and UCB, all unrelated to this manuscript., Grant/research support from: Orphazyme, unrelated to this manuscript., Speakers bureau: Abbvie, BMS, Celgene, Eli Lilly, Janssen, MSD, Novartis, Orphazyme, Pfizer, Roche and UCB, all unrelated to this manuscript., Saskia Lawson-Tovey: None declared, Kimme Hyrich Grant/research support from: BMS, UCB, and Pfizer, all unrelated to this manuscript., Speakers bureau: Abbvie, Loreto Carmona Consultant of: her institute works by contract for laboratories among other institutions, such as Abbvie Spain, Eisai, Gebro Pharma, Merck Sharp & Dohme España, S.A., Novartis Farmaceutica, Pfizer, Roche Farma, Sanofi Aventis, Astellas Pharma, Actelion Pharmaceuticals España, Grünenthal GmbH, and UCB Pharma, all unrelated to this manuscript., Laure Gossec Grant/research support from: AbbVie, Amgen, BMS, Biogen, Celgene, Gilead, Janssen, Lilly, Novartis, Pfizer, Samsung Bioepis, Sanofi-Aventis, UCB, all unrelated to this manuscript., Speakers bureau: Amgen, Lilly, Janssen, Pfizer, Sandoz, Sanofi, Galapagos, all unrelated to this manuscript., Elsa Mateus Grant/research support from: LPCDR received support for specific activities: grants from Abbvie, Novartis, Janssen-Cilag, Lilly Portugal, Sanofi, Grünenthal S.A., MSD, Celgene, Medac, Pharmakern, GAfPA; grants and non-financial support from Pfizer; non-financial support from Grünenthal GmbH, outside the submitted work., Anja Strangfeld Speakers bureau: AbbVie, MSD, Roche, BMS, and Pfizer, all unrelated with this manuscript., BERND RAFFEINER: None declared, Tiphaine Goulenok: None declared, Olilvier Brocq: None declared, Martina Cornalba: None declared, José A Gómez-Puerta Speakers bureau: AbbVie, BMS, GSK, Janssen, Lilly, MSD, Roche and Sanofi., Eric Veillard: None declared, Ludovic Trefond: None declared, Jacques-Eric Gottenberg: None declared, Julien Henry: None declared, Patrick Durez: None declared, Gerd Rüdiger Burmester: None declared, Marta Mosca: None declared, Eric Hachulla: None declared, Hans Bijlsma: None declared, Iain McInnes: None declared, Xavier Mariette Consultant of: BMS, Galapagos, Gilead, Janssen, Novartis, Pfizer, Sanofi-Aventis, UCB, and grant from Ose, all unrelated to this manuscript.

649 COVID BOAST In Practice: Our Experience Implementing BOA Recommendations During the UK Coronavirus Pandemic Peak

Background

In anticipation of the UK coronavirus pandemic peak, BOA published new pandemic-specific guidance (“COVID BOAST”) in April 2020. We describe our experience implementing this restructured T&O service in a busy DGH setting during the pandemic peak.

Method

A rapid retrospective audit was conducted of all patients presenting to our T&O service in April 2020, with particular emphasis compliance with COVID BOAST.

Results

Our service conducted 511 outpatient reviews, and 95 operative procedures. 94% of outpatients were treated non-operatively. We provided telephone appointments to 12.8% of follow-up patients, and 39% of new patients. 82% of patients were treated with removable casts/splints/boots. 23% of patients were discharged direct from VFC or after one face-to-face fracture clinic review. Residual deformity was consciously accepted in 13% of patients. Theatre throughput fell significantly due to pandemic precautions however, femoral neck fracture volumes remained constant.

Conclusions

We demonstrate broad compliance with COVID BOAST guidance. The majority of patients were treated non-operatively, including conscious acceptance of residual deformity. Our pre-existing VFC allowed us to provide a significant number of telephone consultations, although despite the practice shift towards removable splintage, face-to-face consultations were required for clinical and/or radiological assessment. The impact of increased conservative management on patients’ long-term outcomes needs further evaluation.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

AB1017 ANTI RANK LIGAND IN ACUTE CHARCOT NEURO-OSTEOATHROPATHY OF THE FOOT: A PROMISING TREATMENT

Background:

Acute Charcot neuroarthropathy (CN) of the foot is a rare and severe complication of peripheral neuropathy leading to joint destruction. Usual treatment rely on standard pressure offloading and no pharmacological treatment is available. Inflammation and increased osteoclastic activity via receptor activator of nuclear factor (RANK) ligand are major features of acute CN.

Objectives:

To assess clinical, metabolic and radiographic effect of denosumab, a fully human monoclonal antibody against RANK ligand, in acute CN.

Methods:

In this open study, we included all consecutive patients with acute CN treated with denosumab 60 mg in our mixed rheumatology/diabetes clinic dedicated to diabetic foot. Diagnosis of acute CN was based on clinical presentation and supported by biology, radiography, magnetic resonance imaging (MRI). Baseline and follow-up assessment included clinical examination and emission tomography–computed tomography (PET-CT).

Results:

Seven patients with acute CN were treated with denosumab between 2017 and 2019 (age from 43 to 70 years). Five were diabetic. All patients received denosumab, because of failure of standard pressure offloading, with evolving joint destruction of midfoot. CN evolves since a median of 6 months (2 to 20) at denosumab initiation. All patients clinically improved after denosumab injection (table). After a mean follow-up of 16 months, only 1/7 patients had a new flare. In the 4 patients with available follow-up X-ray, structural damage remained stable. In all 3 patients with available PET-CT evolution, the maximum standardized uptake lean value (SUL max) decreased.

Table 1.

Baseline characteristics and follow up treatment

Three patients were retreated, with a mean interval of 6 months: One patients because of persistent clinical and biological inflammation (CRP 17 mg/L), one because of relapse due to intensive walking, and one due to an associated osteoporosis.

No adverse event and hypocalcemia was observed.

Conclusion:

One to three injection of denosumab 60 mg was efficient in preventing flare and further bone destruction in a 16 months medium follow up. These results justify the conduction of a randomized control study to assess the efficacy of denosumab as the first-line pharmacological therapy in acute CN.

References:

[1]Molines L and al. Charcot’s foot: Newest findings on its pathophysiology, diagnosis and treatment. Diabetes Metab. Sept 2010;36(4):251-5.

[2]Mabilleau G, and al. Increased osteoclastic activity in acute Charcot’s osteoarthropathy: the role of receptor activator of nuclear factor-kappaB ligand. Diabetologia. juin 2008;51(6):1035-40.

Disclosure of Interests:

None declared

Disclosure of Interests:

Sandrine Carvès: None declared, Julien Henry: None declared, Murielle BOURGEON GHITTORI: None declared, Rakiba Belkhir: None declared, Gaetane Nocturne: None declared, Florent Besson: None declared, Guillaume Cluzel: None declared, Maud Creze: None declared, Raphaèle Seror Consultant of: BMS UCB Pfizer Roche, Xavier Mariette Consultant of: BMS, Gilead, Medimmune, Novartis, Pfizer, Servier, UCB

Comment répondre aux demandes de mastectomie prophylactique controlatérale après un cancer du sein hors prédisposition génétique ? Perspectives éthiques et cliniques

Les mastectomies prophylactiques controlatérales sont proposées aux patientes présentant une prédisposition génétique ou étant à haut risque familial. Elles augmentent en dehors de ces contextes, alorsmême que la procédure n’apporte pas de bénéfice sur le risque de récidive du cancer du sein. À une époque où l’on prône l’autonomie des patients, quelle place peut-on laisser à la responsabilité du soignant ? Nous verrons comment l’éthique et la clinique viennent mettre un cadre à une médecine devenue toute-puissante.

The role of aquaculture farm biosecurity in global food security

The aquaculture industry can play a key role in global food security; however, the lack of comprehensive implementation of effective biosecurity measures is preventing the sector from reaching its potential. Biosecurity begins with an evaluation of the risk of the introduction of pathogens from outside the system, as well as the spread of pathogenic agents within and from the culture system. This involves establishing a clear picture of the physical infrastructure of the system, systematically identifying the relevant pathways of transmission of pathogenic agents, analysing the risks associated with each pathway and implementing mitigation measures to minimise the risks. The farm biosecurity plan provides benefits that improve health and prevent disease-related losses through the use of best management practices, standard operating procedures, staff training, surveillance, emergency response plans, record keeping and audit of farm performance. Biosecurity supports gains in animal productivity, production and growth, thus ensuring the continuity of supply necessary for food security. Disease puts at risk the sector's resilience and reliability and will continue to limit aquaculture's contribution to global food security until comprehensive biosecurity programmes are in place. Responsibility for biosecurity is shared by all stakeholders. Overarching support from the national and international communities, including investment in innovative solutions, technological advancements and training and education, is required to achieve comprehensive global biosecurity. Implementation requires local leadership and meaningful engagement in the involved industries and communities. Each farmer must be enabled to prevent, detect and respond to disease events at the local level. Only by enabling the individual farmer can there be a decrease in the risk of disease issues becoming regional, national or international.

Abstract P4-02-03: Impact of the 2018 ASCO/CAP HER2 focused update on human epidermal growth factor receptor-2 (HER2) testing in breast cancer: A retrospective review of a single institutional cohort

Background: In the 2013 ASCO/CAP HER2 update, new recommendations for HER2 diagnostic criteria in breast cancer organized in situ hybridization (ISH) results into five categories; group1 (amplified), group 2 (monosomy), group 3 (co-amplified), group 4 (equivocal) and group 5 (non-amplified). Patients falling into groups 2, 3 and 4 were potentially eligible for HER2 targeted therapy, however, there is uncertainty from limited prospective clinical trials that show patients in these uncommon groups would receive the same benefit as group 1. Concern over whether the interpretation criteria should be modified for these uncommon groups led to the recent publication of the 2018 HER2 focused update. This update has modified ISH criteria for groups 2, 3 and 4, recommending the final diagnosis take into consideration both immunohistochemistry (IHC) and ISH results. The publication of this new guideline has prompted us to investigate what impact this would have on our institution.

Materials & Methods: A retrospective review of the URMC pathology database revealed 2,281 cases that had undergone HER2 FISH analysis since the 2013 update. IHC for initial HER2 screening was used, followed by reflex testing of all 2+ results and cases with histopathologic discordance. All 2,281 FISH cases were sorted into their 5 HER2 categories based on the 2013 guidelines. The final HER2 diagnosis for groups 2, 3 and 4 were then re-determined after applying the new criteria presented in the 2018 focused update.

Results: The results from the 2,281 HER2 FISH cases are shown in Tables 1 and 2. The results for group 1 and group 5 cases remained the same. However, for ISH cases in groups 2, 3 and 4, there were alterations in the final HER2 results. All 25 monosomy cases, originally interpreted as HER2 positive by the 2013 guidelines, were now considered HER2 negative. All group 3 (co-amplified) cases remained positive (due to IHC 2+ results). The largest change was that the original 199 equivocal cases, based on the 2013 guidelines, became split into 198 HER2 negative (99.5%) and 1 HER2 positive (0.5%).

Conclusion: Comparison of the HER2 FISH cases between 2013 and 2018 revealed differences in the final HER2 status. Using the 2018 guideline, 13.72% (313 cases) of the 2281 cases were HER2 positive in contrast to 14.77% (337 cases) from 2013. While that is only a difference of 1.05%, the reclassification of 198 of 199 equivocal cases to negative indicates that 9.82% of the final HER2 results for the entire patient cohort was affected. With 266,000 new cases of breast cancer annually, the final HER2 status of approximately 26,000 patients and their potential eligibility for targeted-therapy would change. Further study of the clinical significance of these changes is warranted.

Final ISH HER2 Status (2013)AmplifiedMonosomyCo-AmplifiedEquivocalNon-Amplified272 cases (11.93%)25 cases (1.10%)40 cases (1.75%)199 cases (8.72%)1,745 cases (76.50%)

Citation Format: Hicks DG, D'Aguiar M, Henry J, McMahon L, Buscaglia B, Turner B. Impact of the 2018 ASCO/CAP HER2 focused update on human epidermal growth factor receptor-2 (HER2) testing in breast cancer: A retrospective review of a single institutional cohort [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-02-03.

Abstract P1-03-02: ASCO/CAP human epidermal growth factor receptor-2 (HER2) in situ hybridization (ISH) categories evaluated by quantitative HER2 protein diagnostic methodologies: A comparative analysis

Background: In 2013, the ASCO/CAP consensus panel published updated guidelines for HER2 testing in breast cancer that modified the definition of HER2 amplification by in situ hybridization (ISH), creating five new prognostic categories (group 1: classic amplified, group 2: monosomy, group 3: co-amplified (polysomy), group 4: equivocal, and group 5: classic non-amplified). Patients determined to be ISH amplified, were considered eligible for HER2-directed therapy. Concern over whether patients from non-classic groups 2-4 would benefit from treatment has led to the recent publication of the 2018 HER2 focused update. This update has modified the criteria for interpreting these ISH categories, recommending that the final diagnosis take into consideration a combination of HER2 immunohistochemistry (IHC) and ISH results. With increased emphasis on the HER2 protein assessment, it has prompted us to quantitatively examine HER2 protein expression in the ISH categories, using two different novel technologies. Materials & Methods: A cohort of 170 cases (URMC) and 102 cases (PSHMC) of invasive breast cancers, which had previously undergone HER2 IHC and ISH testing, were selected for this study. Cases were sorted and categorized into the HER2 ISH categories defined by ASCO/CAP. HER2 protein expression was quantitatively measured in the URMC and PSHMC cohorts using a novel immunodetection methodology (streptavidin-coated Phosphor-Integrated Dot (PID) fluorescent nanoparticles), and a novel dual-antibody, proximity-binding immunoassay (HERmark® Breast Cancer Assay, Monogram Biosciences, South San Francisco, California), respectively. HER2 protein expression was compared to the HER2 FISH and IHC results by ASCO/CAP category. Results: Cases in group 1 had a significantly (p &lt; 0.01) higher average PID/cell and HERmark compared to cases in groups 2-5 (Table 1). Cases in groups 2-4 showed lower quantitative levels of HER2 protein expression, similar to the classic non-amplified cases (group 5). Group 1 was further divided into three subgroups (Table 2): Group A - ISH high-level amplified (ratio &gt; 2, HER2 &gt; 6, CEP17 &lt; 2.7), Group B - amplified with elevated CEP17 (ratio &gt; 2, CEP17 &gt; 2.7), and Group C - low-level amplified (ratio &gt; 2, HER2 &gt; 4 and &lt; 6). Group A and B had a significantly (p &lt; 0.01) higher average PID/cell and HERmark compared to Group C. Group C was more comparable to cases in groups 2-5 (Table 1). Conclusion: Our results suggest that quantitative assessment of HER2 protein expression may help to further classify cases for HER2 status for targeted therapy, supporting the 2018 ASCO/CAP recommendation that non-classic ISH results might be resolved by evaluating protein expression. Follow up studies with a larger patient cohort and dual quantitative assessment are warranted.

Average PID/cell and HERmark in ASCO category groupsASCO category groupN (URMC)PID/cell (URMC)*N (PSHMC)HERmark (PSHMC)*18888.07761.521011.20N/A32016.0213.84238.5315.95296.3208.3*averageTable 2:Average PID/cell and HERmark in subgroups of Group 1SubgroupN (URMC)PID/cell (URMC)*N (PSHMC)HERmark (PSHMC)*A24157.66465.7B34101.61044.1C3016.9329.8*average

Citation Format: Buscaglia B, Turner B, Goda H, Huang W, Leitzel K, Natori T, Nakano Y, Okada H, Sperinde J, Ali S, Vasekar M, D'Aguiar M, McMahon L, Henry J, Lipton A, Hicks D. ASCO/CAP human epidermal growth factor receptor-2 (HER2) in situ hybridization (ISH) categories evaluated by quantitative HER2 protein diagnostic methodologies: A comparative analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-03-02.

[Extra-facial Lever granuloma on a herpes zoster scar: Wolf's isotopic response]

BACKGROUND

Granuloma faciale (GF), or facial granuloma of Lever, is an uncommon dermatosis occurring classically on the face. We report a case of a GF on zoster scars located on the trunk, which is a highly particular isotopic response.

PATIENTS AND METHODS

A 60-year-old man with a sole history of left lumbar zoster presented with a skin lesion present for two months. Clinical examination revealed a 2.5-cm papular erythematous lesion that was both infiltrated and pruritic. This lesion was situated precisely on zoster scars. Lab tests revealed no abnormalities. Histopathologic examination showed an inflammatory process without neovessels but rich in eosinophils with chronic vasculitis and polymorphic infiltrate, on which basis GF was diagnosed.

DISCUSSION

GF is a localized form of cutaneous small-vessel vasculitis. Although it usually affects the face, extra-facial locations also exist. The original character of this presentation, aside from the location, is the occurrence of this GF on a zoster scar, which corresponds to Wolf's isotopic response. This phenomenon, described by R. Wolf, comprises the occurrence of a new skin disorder at the site of another unrelated and already healed skin disease, usually herpes. The physiopathology is still unclear. This differs from isomorphic reactions such as Koebner's reaction, which consists of the appearance at an injury site of skin lesions typical of an existing dermatosis but not a new disorder.

CONCLUSION

This is a rare case of Wolf's isotopic response with GF, of which, to our knowledge, there are no reports in the literature.

First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

Group intervention for carers of geriatric patients: experiences from a clinic in India

Sixty per cent of the global elderly population live in low-and middle-income countries, and this proportion was expected to rise to 70% by 2010 (International Institute of Ageing, 2001; Ferri et al, 2005). The 2001 Indian census found over 70 million people aged 60 years or more (considered senior citizens according to the Indian National Policy on Older Persons). Most of those senior citizens live with younger family members and are dependent on them for financial and social support. Hence, any physiological and psychological changes in the older family members affect the younger supportive members as well.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and [Formula: see text] credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-[Formula: see text] requires at least three detectors of sensitivity within a factor of [Formula: see text] of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

"Bottom-up" in situ proteomic differentiation of human and non-human haemoglobins for forensic purposes by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry

RATIONALE

The detection and identification of human blood on crime-related items are of particular relevance to many investigations because shed blood can provide evidence of violent contact between individuals. However, for any detection and identification technique, specificity is a critical performance characteristic to assess; that is, whether the technique has the capability to differentiate between human blood (which usually is of relevance to a criminal investigation) and non-human blood (which usually would not be associated with a crime but may be detected incidentally).

METHODS

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) approaches using "top-down" (detection of intact proteins) and "bottom-up" (detection of tryptic peptide markers) were used to detect and identify haemoglobin in blood from humans and from a range of Australian native mammals; the technique could be carried out directly on blood stains without the need to extract proteins (i.e., in situ measurement). Imaging of haemoglobin was achieved in bloodied fingermarks, including those that had been enhanced using two "industry standard" fingermark enhancement processes.

RESULTS

Differentiation of intact haemoglobin proteins in human and non-human blood using "top-down" MALDI-TOF-MS was difficult. However, in situ "bottom-up" approaches using tandem mass spectrometry (MS/MS) and de novo sequencing of tryptic digest peptides allowed unambiguous differentiation. Imaging mass spectrometry of human haemoglobin, even when it was mixed with animal blood, was achieved in bloodied fingermarks that had been enhanced using two common processes (staining with Amido Black or dusted with magnetic powder) and "lifted" using adhesive tape.

CONCLUSIONS

The MALDI-TOF-MS-based in situ "bottom-up" proteomic methodology described here shows great promise for the detection of human blood and even imaging of blood in bloodied fingermarks. The approach is sensitive, can differentiate between human blood and that from many animals (including several Australian native animals), and can be implemented after traditional crime scene fingermark enhancement techniques have been carried out.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Upper Limits on the Stochastic Gravitational-Wave Background from Advanced LIGO's First Observing Run

A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves to be Ω_{0}<1.7×10^{-7} with 95% confidence, assuming a flat energy density spectrum in the most sensitive part of the LIGO band (20-86 Hz). This is a factor of ∼33 times more sensitive than previous measurements. We also constrain arbitrary power-law spectra. Finally, we investigate the implications of this search for the background of binary black holes using an astrophysical model for the background.

Directional Limits on Persistent Gravitational Waves from Advanced LIGO's First Observing Run

We employ gravitational-wave radiometry to map the stochastic gravitational wave background expected from a variety of contributing mechanisms and test the assumption of isotropy using data from the Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. We also search for persistent gravitational waves from point sources with only minimal assumptions over the 20-1726 Hz frequency band. Finding no evidence of gravitational waves from either point sources or a stochastic background, we set limits at 90% confidence. For broadband point sources, we report upper limits on the gravitational wave energy flux per unit frequency in the range F_{α,Θ}(f)<(0.1-56)×10^{-8}    erg cm^{-2} s^{-1} Hz^{-1}(f/25  Hz)^{α-1} depending on the sky location Θ and the spectral power index α. For extended sources, we report upper limits on the fractional gravitational wave energy density required to close the Universe of Ω(f,Θ)<(0.39-7.6)×10^{-8}  sr^{-1}(f/25  Hz)^{α} depending on Θ and α. Directed searches for narrowband gravitational waves from astrophysically interesting objects (Scorpius X-1, Supernova 1987 A, and the Galactic Center) yield median frequency-dependent limits on strain amplitude of h_{0}<(6.7,5.5,  and  7.0)×10^{-25}, respectively, at the most sensitive detector frequencies between 130-175 Hz. This represents a mean improvement of a factor of 2 across the band compared to previous searches of this kind for these sky locations, considering the different quantities of strain constrained in each case.

Mobile Health Technology Can Objectively Capture Physical Activity (PA) Targets Among African-American Women Within Resource-Limited Communities-the Washington, D.C. Cardiovascular Health and Needs Assessment

BACKGROUND

Little is understood about using mobile health (mHealth) technology to improve cardiovascular (CV) health among African-American women in resource-limited communities.

METHODS

We conducted the Washington, D.C. CV Health and Needs Assessment in predominantly African-American churches in city wards 5, 7, and 8 with the lowest socioeconomic status based on community-based participatory research (CBPR) principles. The assessment measured CV health factors: body mass index (BMI), fasting blood glucose and cholesterol, blood pressure, fruit/vegetable (F/V) intake, physical activity (PA), and smoking. Participants were trained to use a PA monitoring wristband to measure 30 days of PA, wirelessly upload the PA data to hubs at the participating churches, and access their data from a church/home computer. CV health factors were compared across weight classes.

RESULTS

Among females (N = 78; 99 % African-American; mean age = 59 years), 90 % had a BMI categorized as overweight/obese. Across weight classes, PA decreased and self-reported sedentary time (ST) increased (p ≤ 0.05). Diastolic blood pressure and glucose increased across weight classes (p ≤ 0.05); however, cholesterol, glucose, and BP were near intermediate CV health goals.

CONCLUSIONS

Decreased PA and increased ST are potential community intervention targets for overweight and obese African-American women in resource-limited Washington D.C. areas. mHealth technology can assist in adapting CBPR intervention resources to improve PA for African-American women in resource-limited communities.

GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Microwave-assisted Bi₂Se₃ nanoparticles using various organic solvents

Microwave assisted Bi2Se3 nanoparticles were synthesized from five different solvents DMF, EG, EG+H2O, EDA+dil.HNO3 and N2H4+H2O+Ethanol. The influence of solvents on purity of the compound was analysed by using X-ray diffraction patterns. The result indicates pure rhombohedral Bi2Se3 nanoparticles formed for N2H4+H2O+Ethanol. The presence of vibrational bands in the range of 400-800 cm(-1) is confirmed the formation of Bi2Se3. The maximum optical absorption observed around 450 nm and the band gap values are found in the range of 1.5 eV-2.17 eV for all the solvents. The nanostructure of the Bi2Se3 particles change with solvents. From the experimental results, the solvent N2H4+H2O+Ethanol produces pure nanosize Bi2Se3 particles under the microwave assisted method.

Dosimetric quantification of dose fall-off in liver SBRT planning using dual photon energy IMRT

INTRODUCTION

The purpose of this study was to dosimetrically compare 6 MV, 10 MV and a hybrid of 6 and 10 MV photon beam energies in liver stereotactic body radiotherapy (SBRT) patients using a fixed-field IMRT technique. The objectives of the study were to evaluate dosimetric differences in the target volume and investigate if dose fall-off could be improved with 10MV beam energy.

METHODS AND MATERIALS

Sixteen (n=16) liver SBRT patients previously treated using a non-coplanar, fixed-field IMRT technique with 6 MV were replanned using 10 MV and dual photon energy (DE). Plans were generated in Pinnacle³ using a Novalis Tx with HD120 MLC. For each patient, three plans with the same beam geometry were created using 6 MV, 10 MV and DE. For DE plans, the central axis effective depth from each beam was calculated and the values averaged. Beams with an effective depth greater than the average were assigned to 10 MV. All patients were optimized with the same planning objectives and normalized such that 98% of the target received 100% of prescription dose. Metrics used for comparison were the homogeneity index, conformity indices, and dose fall-off parameters at various isodose levels.

RESULTS

The three techniques showed comparable PTV conformity and inhomogeneity for all patients-differences in the median values 「0.6%. With regard to dose fall-off, no statistically significant differences were noted among the techniques for R₈₀, R₆₀ and R₅₀; however, 10 MV showed statistical significance in the lowest median values of R₄₀, R₃₀, and R₂₀. Ten MV and DE plans also demonstrated a statistically significant reduction in the total number of monitor units (MU) of 14.9% (p 「0.01) and 12.0% (p 「0.01) as compared to 6 MV, respectively.

CONCLUSION

Both dual energy and 10 MV photon beams had similar PTV dosimetric characteristics to 6 MV for liver SBRT but findings show faster dose fall-off for 10 MV and DE plans at the 40%, 30%, and 20% prescription isodose levels.