Characterisation and correction of polarisation effects in fluorescently labelled fibres

Many biological structures take the form of fibres and filaments, and quantitative analysis of fibre organisation is important for understanding their functions in both normal physiological conditions and disease. In order to visualise these structures, fibres can be fluorescently labelled and imaged, with specialised image analysis methods available for quantifying the degree and strength of fibre alignment. Here we show that fluorescently labelled fibres can display polarised emission, with the strength of this effect varying depending on structure and fluorophore identity. This can bias automated analysis of fibre alignment and mask the true underlying structural organisation. We present a method for quantifying and correcting these polarisation effects without requiring polarisation-resolved microscopy and demonstrate its efficacy when applied to images of fluorescently labelled collagen gels, allowing for more reliable characterisation of fibre microarchitecture.

Shoulder Muscle Dosimetry and Post-Treatment Rehabilitation Utilization for Early-Stage Breast Cancer Patients

PURPOSE/OBJECTIVE(S)

Rehabilitation services for recovery of impaired physical function following breast cancer treatments are largely underutilized. We previously found that breast cancer survivors treated with radiation who received higher radiation doses to the pectoralis major are more likely to self-report shoulder pain and disability. This study aims to address whether radiation dose delivered to the pectoralis major (Pmaj) and pectoralis minor (Pmin) are correlated with referrals for rehabilitation services post-treatment.

MATERIALS/METHODS

A retrospective 1:1 matched case-control study was conducted for breast cancer patients who were and were not referred for breast or shoulder rehabilitation services between 2014-2019 at a single academic institution. Patients were included if they had a lumpectomy and adjuvant radiation without regional nodal irradiation. Cohorts were matched based on age, axillary surgery (none vs. sentinel lymph node biopsy (SLNB)), and use of radiation boost. We used non-parametric Mann-Whitney U tests to determine whether Pmaj or Pmin doses (mean, V50Gy, V45Gy, V40Gy, V35Gy, V30Gy, V20Gy) were different between the two groups. Muscle doses were converted to EQD2 assuming an α/β ratio of 2.5.

RESULTS

In our study of 30 patients of a median age 57 years (IQR 12.75), 20 (66.67%) patients underwent SLNB in addition to lumpectomy. Median tumor size was 1.1cm (range 0.16 - 7.30cm). Stage was 0 for 11 patients (36.67%), I for 14 patients (46.67%), and II for 5 patients (16.67%). 3D conformal radiation was delivered to the whole breast with a moderately hypofractionated (n = 17) or conventionally fractionated regimen (n = 13). The most common rehabilitation diagnoses were lymphedema (n = 8), scar management (n = 7) and shoulder pain (n = 5). Mean dose to both the Pmaj (20.8Gy vs. 18.6Gy; p = 0.02) and Pmin (30.6Gy vs. 24.6Gy; p = 0.01) were significantly higher in patients who received post-treatment rehabilitation compared to those without. The V40Gy, V35Gy, V30Gy and V20Gy (all p<0.02) for the Pmin and V35Gy, V30Gy and V20Gy for the Pmaj (all p<0.04) were also significantly higher in those who underwent rehabilitation.

CONCLUSION

In this cohort of patients with early-stage breast cancer, increased mean doses to the pectoralis muscles were correlated with increased use of rehabilitation services after radiation. Physicians might consider using these dosimetric data to complement clinical symptoms in the decision-making process for referrals for rehabilitation services. This may help facilitate earlier referral to rehabilitation interventions, which is important since early intervention is correlated with improved shoulder morbidity.

Impact of Breast Volume on Achieving a Conservative Heart and Target Coverage Metric for Patients Receiving Whole Breast Radiotherapy in a Statewide Consortium

PURPOSE/OBJECTIVE(S)

Radiation to large breast volumes (BV) has been associated with increased dose inhomogeneities, breast fibrosis, and induration. Radiation exposure to the heart during breast radiotherapy has been associated with late cardiovascular morbidity and mortality. This study, therefore, investigates the impact of BV on achieving optimal lumpectomy cavity target coverage (V95% [%] >95) while maintaining mean heart dose constraints (MHD, mean [Gy] <1) across a range of BV from patients enrolled in a statewide consortium.

MATERIALS/METHODS

A retrospective analysis was conducted for 2,506 patients receiving left-sided whole breast moderately-hypofractionated (2.5-2.8 Gy/fx) radiotherapy without nodal fields between 2018-2022. The BV was calculated for each patient from contours in the treatment planning system, and the volume distribution partitioned into quartiles. Dosimetric parameters were calculated from dose-volume histograms. The percentage of patients in which the metrics were achieved was calculated for each BV quartile for different treatment positions: all positions, supine, supine with breathing motion management, and prone.

RESULTS

The BV ranges within the quartiles (∼620 patients/quartile) were ≤720.0 cc, 720.1 to ≤1065.0 cc, 1065.1 to ≤1500.0 cc, and >1500.0 cc for quartiles Q1-Q4, respectively. Of the 2,506 patients, 76% were treated supine (of which 41.6% were treated using breathing motion management techniques), 23.5% were treated prone, and 0.5% were treated decubitus. Discrete percentages of patients able to meet the metrics are provided in the table. An increase in BV from Q1 to Q4 correlated with lower percentages of patients meeting the MHD metric, however no correlation was observed between BV and target coverage. Treating supine with breathing motion management resulted in a higher percentage of patients meeting the MHD metric (odds ratio (OR) = 1.96 relative to supine without motion management, p<0.0001), while the prone setup proved to be the superior technique across all quartiles (OR = 3.95 relative to supine, p<0.0001).

CONCLUSION

Increasing BVs resulted in lower percentages of patients receiving MHD≤1 Gy. Thus, cardiac sparing may be more difficult to achieve in patients with larger BV. Utilization of alternate treatment positions, such as supine with breathing motion management and prone, greatly improved the percentage of patients able to meet the MHD metric without sacrificing target coverage in all quartiles. Prone positioning was the technique least susceptible to BV effects in meeting the MHD≤1 Gy goal.

Factors Associated with Cardiac Radiation Dose Reduction Following Hypofractionated Radiation Therapy for Localized, Left-Sided Breast Cancer in a Large Statewide Quality Consortium

PURPOSE/OBJECTIVE(S)

Limiting radiation dose to the heart is important for minimizing the risk of long-term cardiac toxicity in patients with left-sided early-stage breast cancer.

MATERIALS/METHODS

Prospectively collected dosimetric data were analyzed for patients undergoing hypofractionated radiation therapy to the left breast for localized node-negative breast cancer within the Michigan Radiation Oncology Quality Consortium (MROQC) from 2016-2022. Goals for limiting cardiac dose were adjusted over time. From 2016-2020, the cardiac quality metric focused on total mean heart dose (MHD) from the composite whole breast and boost plans, tightening from a goal of MHD ≤2 Gy to MHD ≤1.2 Gy by 2020. In 2021-2022, the cardiac metric transitioned to a combined goal of MHD ≤1.0 Gy from the whole breast plan and ≥95% lumpectomy cavity planning target volume (PTV) receiving 95% of the prescription dose. Separate multivariate logistic regression models were developed to assess for covariates associated with meeting the MHD goal in 2016-2020 and combined MHD/PTV coverage goal in 2021-2022.

RESULTS

In total, 4,165 patients were analyzed with a median age of 64 years. Most patients (86%) had either Tis or T1 disease, and 66% received hormone therapy. Baseline demographic and disease characteristics did not change substantially between treatment periods. Use of breath-hold or motion gating increased from 42% in 2016-2020 to 46% in 2021-2022. Similarly, use of prone positioning increased from 12% to 20%. From 2016-2020, 90.9% of plans achieved the MHD goal, compared to 93.6% of plans achieving the composite MHD/PTV goal from 2021-2022. On multivariate analysis in the 2016-2020 cohort, treatment with motion management (OR 5.20, 95% CI [3.59-7.54], p<0.0001) or prone positioning (OR 3.21, 95% CI [1.85-5.57], p < 0.0001) were associated with meeting the MHD goal, while receipt of boost (OR 0.25, 95% CI [0.17-0.39], p<0.0001) and omission of hormone therapy (OR 0.65, 95% CI [0.49-0.88], p = 0.0047), were associated with not meeting the MHD goal. During the era including composite heart dose and PTV coverage goals (2021-2022), treatment with motion management (OR 1.89, 95% CI [1.12-3.21], p = 0.018) or prone positioning (OR 3.71, 95% CI [1.73-7.95], p = 0.0008) were associated with meeting the combined goal, while larger breast volume (≥1440 cc, OR 0.34, 95% CI [0.13 - 0.91], p = 0.031) and treatment at an academic center (OR 0.36, 95% CI [0.22-0.67], p = 0.0009) were associated with not meeting the combined goal.

CONCLUSION

In our statewide consortium, rates of compliance with aggressive targets for limiting cardiac dose remain high, despite tightening of these goals to include lower mean heart doses and inclusion of a concurrent PTV coverage goal. Treatment using motion management or prone positioning is associated with achieving the cardiac dose goals.

POS0339 POINTS TO CONSIDER AT THE EARLIEST STAGES OF THE DIAGNOSIS AND MANAGEMENT OF HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS/MACROPHAGE ACTIVATION SYNDROME (HLH/MAS)

Background

Hemophagocytic Lymphohistiocytosis (HLH) and Macrophage Activation Syndrome (MAS) are life-threatening systemic hyperinflammatory syndromes that occur in many contexts and are often called by many names. They nevertheless can progress rapidly, and early identification and management are critical for preventing organ failure and mortality.

Objectives

The purpose of this effort was to develop a series of ‘points to consider’ to assist clinicians at the earliest stages of evaluation and diagnosis, management, and monitoring of patients with HLH/MAS in order to improve patient outcomes.

Methods

A working group of adult and pediatric rheumatologists (14), hematologist/oncologists (4), immunologists (2), infectious disease specialists (2), intensivists (3), allied health care professionals (1), and patients/parents (2) formulated relevant research questions for a systematic literature review (SLR). We then used the SLR results, Delphi questionnaires, and consensus methodology to devise and refine overarching and specific ‘points to consider’ statements.

Results

The group arrived at six overarching statements and 24 specific points-to-consider relevant to early decision-making in diagnostics, initial management, and monitoring of HLH/MAS. Major themes included the a) need for prompt recognition, evaluation, and management of underlying triggers and conditions, b) multi-disciplinary/expert input, and c) early, tailored intervention with the goals of halting disease progression and preventing life- and organ-threatening immunopathology

Conclusion

These 2022 EULAR/ACR Points to Consider provide guidance on the initial evaluation, management, and monitoring of patients during the initial consideration of HLH/MAS.

Disclosure of Interests

Bita Shakoory: None declared, Ashley Geerlinks: None declared, Marta Wilejto: None declared, Kate Kernan: None declared, Erkan Demirkaya: None declared, Angelo Ravelli: None declared, Rashmi Sinha: None declared, Raphaela goldbach-mansky Grant/research support from: SOBI, Novartis, Regneneron, IFM, Lilly, Pfizer, Fabrizio De Benedetti Consultant of: abbvie, sobi, novimmune, novartis, roche, sanofi, Grant/research support from: sobi novimmune novartis roche sanofi, Rebecca Marsh: None declared, Scott Canna Consultant of: Simcha Therapeutics, Grant/research support from: Immvention therapeutics, AB2Bio Ltd, Novartis

Engaging a wider public health workforce: bringing public health into architecture education

Background

Current public health challenges necessitate the closer working of public health with built environment professionals. Despite growing evidence of benefits, there remains little progress in practice. Architects can play a key role in ensuring urban and building design is health promoting, however there is no requirement to teach health by architectural accreditation bodies across Europe.

Objectives

In the United Kingdom in 2010, the Public Health Practitioner in Residence programme (PHPiR) was established to address this situation. Public health professionals are embedded within the Faculty of Environment and Technology at the University of the West of England, and contribute to research, pedagogic programme development, teaching and mentoring. The aim was to embed public health concepts and issues into architecture training, to empower the profession as part of the wider workforce, to improve health and wellbeing when designing buildings and places. The PHPiR was evaluated using the Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework. Data was collected (questionnaires, focus group, semi-structured interviews, programme documentation) on a Masters of Architecture cohort (N = 34) at intervals from 2011-2019 to see if the PHPiR has long lasting effects as students enter practice.

Results

Public health concepts including; inequalities, life course approach, and social capital, became embedded into the architecture curriculum. Projects produced had increased reference to wider health promoting issues and participants thinking shifted from the building itself to who would use the building, suggesting the intervention achieved its aims.

Conclusions

The PHPiR offers a novel approach for built environment professions to better understand public health issues and the relevance to their chosen fields. This model could be applied to other courses and replicated in educational institutions and public health training programmes across Europe.

Key messages

The PHPiR influenced the architecture curriculum, improved architects understanding and public health issues and concepts, and empowered them to create more health promoting environments. Embedding public health professionals into training for other disciplines may be an effective, sustainable method for increasing the wider public health workforce.

Seasonal intensification and trends of rogue wave events on the US western seaboard

Studies of changes in wave climate typically consider trends in sea state statistics, such as the significant wave height. However, the temporal variability of individual rogue waves, which pose a hazard to users of the sea and coastal environment has not been investigated. We use time series of continuous surface elevation over 124–270 months (spanning 1994–2016), from 15 wave buoys along the US western seaboard, to investigate regional trends in significant wave height and individual rogue waves. We find high spatial variability in trends in significant wave height and rogue waves across the region. Rogue wave occurrence displays a mostly decreasing trend, but the relative height – or severity – of the waves is increasing. We also identify seasonal intensification in rogue waves with increased rogue wave occurrence, of higher severity, in the winter than in the summer. Therefore, the common practice of stating a single occurrence likelihood for an ocean basin is not valid. In addition, the buoy data show that the magnitude and significance of trends in significant wave height increases towards higher percentiles, supporting previous findings.

Songs, Rockets and Whistling Kettles: Electroencephalographic Changes in Drug Related Auditory Disturbances and Treatment with Acupuncture and Transcutaneous Electrical Nerve Stimulation

Three patients with unilateral auditory disturbances (singing voices, rockets and gongs, and whistling kettles) are described. The symptoms occurred during benzodiazepine withdrawal in two patients and the instigation of nefopam treatment in one. All patients had mild hearing loss and abnormal auditory evoked potentials. Two showed marked asymmetry of background EEG rhythms over the temporal lobe. In two of the patients the symptoms responded partially to TENS and/or acupuncture.

Adherence to guidelines regarding total hip replacement for fractured neck of femur

Introduction In 2011 the National Institute for Health and Care Excellence (NICE) published guidelines suggesting that clinicians offer total hip replacement (THR) to patients with displaced intracapsular hip fractures who could walk independently outside with no aids or one stick, who are not cognitively impaired and are ASA (American Society of Anesthesiologists) grade ≤2. They also stated that best practice is operating within 36 hours of presentation. This audit aimed to determine whether Scarborough Hospital was following these guidelines and compared the results with the national average. Methods Two years of data (January 2012 - December 2013) were collected retrospectively from Scarborough Hospital's hip fracture database on all patients presenting with an intracapsular hip fracture. Data were analysed to determine whether patients who had a THR fulfilled NICE criteria. Furthermore, patients with hemiarthroplasties who were eligible for THRs were identified. Finally, the time to surgery was calculated to examine whether patients receiving THRs waited longer than patients receiving hemiarthroplasties. Results In 2012, 48.6% of all eligible patients received a THR while in 2013 the figure was 55.9%. These percentages are much higher than the national average. However, 36 (53.7%) of the 67 patients who received a THR did not fulfil all the NICE criteria, mainly owing to high ASA grade. The mean time from presentation to theatre for THR was 8 hours and 37 minutes longer for THR patients than for hemiarthroplasty in 2012. This difference was reduced to 2 hours and 12 minutes in 2013. Conclusions Small general hospitals can meet and even exceed the standards regarding treatment strategies for hip factures. However, there is still room for improvement. Departmental training may be useful in achieving this aim. The anaesthetic team should be involved at the earliest opportunity, to help optimise patients preoperatively and determine whether patients listed for THR with higher ASA grades are suitable for this surgery.

Neuropathological changes in the nucleus basalis in schizophrenia

The nucleus basalis has not been examined in detail in severe mental illness. Several studies have demonstrated decreases in glia and glial markers in the cerebral cortex in schizophrenia, familial bipolar disorder and recurrent depression. Changes in neocortical neuron size and shape have also been reported. The nucleus basalis is a collection of large cholinergic neurons in the basal forebrain receiving information from the midbrain and limbic system, projecting to the cortex and involved with attention, learning and memory, and receives regulation from serotonergic inputs. Forty-one cases aged 41-60 years with schizophrenia or major depressive disorder with age-matched controls were collected. Formalin-fixed paraffin-embedded coronal nucleus basalis sections were histologically stained for oligodendrocyte identification with cresyl-haematoxylin counterstain, for neuroarchitecture with differentiated cresyl violet stain and astrocytes were detected by glial fibrillary acid protein immunohistochemistry. Cell density and neuroarchitecture were measured using Image Pro Plus. There were larger NB oval neuron soma in the combined schizophrenia and major depression disorder groups (p = 0.038), with no significant change between controls and schizophrenia and major depression disorder separately. There is a significant reduction in oligodendrocyte density (p = 0.038) in the nucleus basalis in schizophrenia. The ratio of gemistocytic to fibrillary astrocytes showed a greater proportion of the former in schizophrenia (18.1 %) and major depressive disorder (39.9 %) than in controls (7.9 %). These results suggest glial cell abnormalities in the nucleus basalis in schizophrenia possibly leading to cortical-limbic disturbance and subcortical dysfunction.

Use of anterior temporal lobectomy for epilepsy in a community-based population

OBJECTIVE

To assess the hypothesis that use of anterior temporal lobectomy (ATL) for temporal epilepsy has diminished over time.

DESIGN

Population-based cohort study.

SETTING

The Rochester Epidemiology Project based in Olmsted County, Minnesota.

PARTICIPANTS

Residents of Olmsted County.

MAIN OUTCOME MEASURES

Poisson regression was used to evaluate changes in ATL use over time by sex.

RESULTS

Over a 17-year period, from 1993 to 2009, 847ATLs were performed with the primary indication of epilepsy(average, 50 procedures/y). Of these, 26 occurred among Olmsted County residents. The use rates declinedsignificantly between 1993 and 2000 (8 years) and 2001 and 2009 (9 years) according to Poisson regression analysis, from 1.9 to 0.7 per 100 000 person-years(P=.01). The rate of ATL use among Olmsted County residents was 1.2 (95% CI, 0.9 to 2.4) per 100 000 person years of follow-up over this 17-year period. The sex specific rates were 1.6 (95% CI, 0.9 to 2.4) and 0.7 (95%CI, 0.2 to 1.3) per 100 000 person-years for females and males, respectively.

CONCLUSIONS

In this community-based cohort, the rate of ATL use was 1.2 per 100 000 person-years of followup.Use of this procedure has declined over time; the reasons for this are unknown but do not include referral pattern changes.

Data mining neocortical high-frequency oscillations in epilepsy and controls

Transient high-frequency (100-500 Hz) oscillations of the local field potential have been studied extensively in human mesial temporal lobe. Previous studies report that both ripple (100-250 Hz) and fast ripple (250-500 Hz) oscillations are increased in the seizure-onset zone of patients with mesial temporal lobe epilepsy. Comparatively little is known, however, about their spatial distribution with respect to seizure-onset zone in neocortical epilepsy, or their prevalence in normal brain. We present a quantitative analysis of high-frequency oscillations and their rates of occurrence in a group of nine patients with neocortical epilepsy and two control patients with no history of seizures. Oscillations were automatically detected and classified using an unsupervised approach in a data set of unprecedented volume in epilepsy research, over 12 terabytes of continuous long-term micro- and macro-electrode intracranial recordings, without human preprocessing, enabling selection-bias-free estimates of oscillation rates. There are three main results: (i) a cluster of ripple frequency oscillations with median spectral centroid = 137 Hz is increased in the seizure-onset zone more frequently than a cluster of fast ripple frequency oscillations (median spectral centroid = 305 Hz); (ii) we found no difference in the rates of high frequency oscillations in control neocortex and the non-seizure-onset zone neocortex of patients with epilepsy, despite the possibility of different underlying mechanisms of generation; and (iii) while previous studies have demonstrated that oscillations recorded by parenchyma-penetrating micro-electrodes have higher peak 100-500 Hz frequencies than penetrating macro-electrodes, this was not found for the epipial electrodes used here to record from the neocortical surface. We conclude that the relative rate of ripple frequency oscillations is a potential biomarker for epileptic neocortex, but that larger prospective studies correlating high-frequency oscillations rates with seizure-onset zone, resected tissue and surgical outcome are required to determine the true predictive value.

Evaluation of methods for measuring particulate matter emissions from gas turbines

The project SAMPLE evaluated methods for measuring particle properties in the exhaust of aircraft engines with respect to the development of standardized operation procedures for particulate matter measurement in aviation industry. Filter-based off-line mass methods included gravimetry and chemical analysis of carbonaceous species by combustion methods. Online mass methods were based on light absorption measurement or used size distribution measurements obtained from an electrical mobility analyzer approach. Number concentrations were determined using different condensation particle counters (CPC). Total mass from filter-based methods balanced gravimetric mass within 8% error. Carbonaceous matter accounted for 70% of gravimetric mass while the remaining 30% were attributed to hydrated sulfate and noncarbonaceous organic matter fractions. Online methods were closely correlated over the entire range of emission levels studied in the tests. Elemental carbon from combustion methods and black carbon from optical methods deviated by maximum 5% with respect to mass for low to medium emission levels, whereas for high emission levels a systematic deviation between online methods and filter based methods was found which is attributed to sampling effects. CPC based instruments proved highly reproducible for number concentration measurements with a maximum interinstrument standard deviation of 7.5%.

Epilepsy surgery outcomes in temporal lobe epilepsy with a normal MRI

PURPOSE

To determine the long-term efficacy of anterior temporal lobectomy for medically refractory temporal lobe epilepsy in patients with nonlesional magnetic resonance imaging (MRI).

METHODS

We identified a retrospective cohort of 44 patients with a nonlesional modern "seizure protocol" MRI who underwent anterior temporal lobectomy for treatment of medically refractory partial epilepsy. Postoperative seizure freedom was determined by Kaplan-Meyer survival analysis. Noninvasive preoperative diagnostic factors potentially associated with excellent surgical outcome were examined by univariate analysis in the 40 patients with follow-up of >1 year.

RESULTS

Engel class I outcomes (free of disabling seizures) were observed in 60% (24 of 40) patients. Preoperative factors associated with Engel class I outcome were: (1) absence of contralateral or extratemporal interictal epileptiform discharges, (2) subtraction ictal single photon emission computed tomography (SPECT) Coregistered to MRI (SISCOM) abnormality localized to the resection site, and (3) subtle nonspecific MRI findings in the mesial temporal lobe concordant to the resection.

DISCUSSION

In carefully selected patients with temporal lobe epilepsy and a nonlesional MRI, anterior temporal lobectomy can often render patients free of disabling seizures. This favorable rate of surgical success is likely due to the detection of concordant abnormalities that indicate unilateral temporal lobe epilepsy in patients with nonlesional MRI.