Numerical prediction of the ballistic performance of hygrothermally aged CFRP laminates using a multi-scale modelling approach

A multi-scale modelling strategy is proposed to investigate the potential effects of hygrothermal ageing on the ballistic performance of CFRP laminates. At the micro-scale, damage evolution due to cyclic hygrothermal loads is simulated on a representative microstructure using an adapted fatigue damage law. Then, the results of the micro-mechanical analysis are used to measure the predicted transverse crack density and calibrate a meso-scale material model with the effects of micro-scale damage. Finally, a meso-scale impact model is generated with seeded transverse cracks at the predicted crack density and the calibrated material properties from the homogenisation step, which allows for the performance of the laminate to be compared at different stages of hygrothermal ageing damage.

High-fidelity damage modelling of CFRP laminates for impact and crashworthiness applications – dynamic tube crushing simulations

Drop weight impact experiments were conducted on angle-ply carbon fibre reinforced polymer (CFRP) composite crush tubes. The dynamic response was modelled using explicit finite element methods and continuum damage mechanics and cohesive zone modelling in both Abaqus/Explicit and LS-DYNA. User-defined constitutive models for the intra-ply behaviour were used and a fibre-aligned meshing technique was implemented. The results of the experiments and simulations are compared to evaluate accuracy of the different modelling techniques, highlighting the advantages and drawbacks of each approach. Among these, the choice of meshing strategy is shown to be especially important in capturing the physical propagation of cracks and damage mechanisms in CFRP laminates.

Determination of Brain Death/Death by Neurologic Criteria: The World Brain Death Project

IMPORTANCE

There are inconsistencies in concept, criteria, practice, and documentation of brain death/death by neurologic criteria (BD/DNC) both internationally and within countries.

OBJECTIVE

To formulate a consensus statement of recommendations on determination of BD/DNC based on review of the literature and expert opinion of a large multidisciplinary, international panel.

PROCESS

Relevant international professional societies were recruited to develop recommendations regarding determination of BD/DNC. Literature searches of the Cochrane, Embase, and MEDLINE databases included January 1, 1992, through April 2020 identified pertinent articles for review. Because of the lack of high-quality data from randomized clinical trials or large observational studies, recommendations were formulated based on consensus of contributors and medical societies that represented relevant disciplines, including critical care, neurology, and neurosurgery.

EVIDENCE SYNTHESIS

Based on review of the literature and consensus from a large multidisciplinary, international panel, minimum clinical criteria needed to determine BD/DNC in various circumstances were developed.

RECOMMENDATIONS

Prior to evaluating a patient for BD/DNC, the patient should have an established neurologic diagnosis that can lead to the complete and irreversible loss of all brain function, and conditions that may confound the clinical examination and diseases that may mimic BD/DNC should be excluded. Determination of BD/DNC can be done with a clinical examination that demonstrates coma, brainstem areflexia, and apnea. This is seen when (1) there is no evidence of arousal or awareness to maximal external stimulation, including noxious visual, auditory, and tactile stimulation; (2) pupils are fixed in a midsize or dilated position and are nonreactive to light; (3) corneal, oculocephalic, and oculovestibular reflexes are absent; (4) there is no facial movement to noxious stimulation; (5) the gag reflex is absent to bilateral posterior pharyngeal stimulation; (6) the cough reflex is absent to deep tracheal suctioning; (7) there is no brain-mediated motor response to noxious stimulation of the limbs; and (8) spontaneous respirations are not observed when apnea test targets reach pH <7.30 and Paco2 ≥60 mm Hg. If the clinical examination cannot be completed, ancillary testing may be considered with blood flow studies or electrophysiologic testing. Special consideration is needed for children, for persons receiving extracorporeal membrane oxygenation, and for those receiving therapeutic hypothermia, as well as for factors such as religious, societal, and cultural perspectives; legal requirements; and resource availability.

CONCLUSIONS AND RELEVANCE

This report provides recommendations for the minimum clinical standards for determination of brain death/death by neurologic criteria in adults and children with clear guidance for various clinical circumstances. The recommendations have widespread international society endorsement and can serve to guide professional societies and countries in the revision or development of protocols and procedures for determination of brain death/death by neurologic criteria, leading to greater consistency within and between countries.

Inter-fraction robustness of intensity-modulated proton therapy in the post-operative treatment of oropharyngeal and oral cavity squamous cell carcinomas

OBJECTIVE

To evaluate dosimetric consequences of inter-fraction setup variation and anatomical changes in patients receiving multifield optimised (MFO) intensity modulated proton therapy for post-operative oropharyngeal (OPC) and oral cavity (OCC) cancers.

METHODS

Six patients receiving MFO for post-operative OPC and OCC were evaluated. Plans were robustly optimised to clinical target volumes (CTVs) using 3 mm setup and 3.5% range uncertainty. Weekly online cone beam CT (CBCT) were performed. Planning CT was deformed to the CBCT to create virtual CTs (vCTs) on which the planned dose was recalculated. vCT plan robustness was evaluated using a setup uncertainty of 1.5 mm and range uncertainty of 3.5%. Target coverage, D95%, and hotspots, D0.03cc, were evaluated for each uncertainty along with the vCT-calculated nominal plan. Mean dose to organs at risk (OARs) for the vCT-calculated nominal plan and relative % change in weight from baseline were evaluated.

RESULTS

Robustly optimised plans in post-operative OPC and OCC patients are robust against inter-fraction setup variations and range uncertainty. D0.03cc in the vCT-calculated nominal plans were clinically acceptable across all plans. Across all patients D95% in the vCT-calculated nominal treatment plan was at least 100% of the prescribed dose. No patients lost ≥10% weight from baseline. Mean dose to the OARs and max dose to the spinal cord remained within tolerance.

CONCLUSION

MFO plans in post-operative OPC and OCC patients are robust to inter-fraction uncertainties in setup and range when evaluated over multiple CT scans without compromising OAR mean dose.

ADVANCES IN KNOWLEDGE

This is the first paper to evaluate inter-fraction MFO plan robustness in post-operative head and neck treatment.

Early Signs Monitoring to Prevent Relapse in Psychosis and Promote Well-Being, Engagement, and Recovery: Protocol for a Feasibility Cluster Randomized Controlled Trial Harnessing Mobile Phone Technology Blended With Peer Support

Background

Relapse in schizophrenia is a major cause of distress and disability and is predicted by changes in symptoms such as anxiety, depression, and suspiciousness (early warning signs [EWSs]). These can be used as the basis for timely interventions to prevent relapse. However, there is considerable uncertainty regarding the implementation of EWS interventions.

Objective

This study was designed to establish the feasibility of conducting a definitive cluster randomized controlled trial comparing Early signs Monitoring to Prevent relapse in psychosis and prOmote Well-being, Engagement, and Recovery (EMPOWER) against treatment as usual (TAU). Our primary outcomes are establishing parameters of feasibility, acceptability, usability, safety, and outcome signals of a digital health intervention as an adjunct to usual care that is deliverable in the UK National Health Service and Australian community mental health service (CMHS) settings. We will assess the feasibility of candidate primary outcomes, candidate secondary outcomes, and candidate mechanisms for a definitive trial.

Methods

We will randomize CMHSs to EMPOWER or TAU. We aim to recruit up to 120 service user participants from 8 CMHSs and follow them for 12 months. Eligible service users will (1) be aged 16 years and above, (2) be in contact with local CMHSs, (3) have either been admitted to a psychiatric inpatient service or received crisis intervention at least once in the previous 2 years for a relapse, and (4) have an International Classification of Diseases-10 diagnosis of a schizophrenia-related disorder. Service users will also be invited to nominate a carer to participate. We will identify the feasibility of the main trial in terms of recruitment and retention to the study and the acceptability, usability, safety, and outcome signals of the EMPOWER intervention. EMPOWER is a mobile phone app that enables the monitoring of well-being and possible EWSs of relapse on a daily basis. An algorithm calculates changes in well-being based on participants’ own baseline to enable tailoring of well-being messaging and clinical triage of possible EWSs. Use of the app is blended with ongoing peer support.

Results

Recruitment to the trial began September 2018, and follow-up of participants was completed in July 2019. Data collection is continuing. The database was locked in July 2019, followed by analysis and disclosing of group allocation.

Conclusions

The knowledge gained from the study will inform the design of a definitive trial including finalizing the delivery of our digital health intervention, sample size estimation, methods to ensure successful identification, consent, randomization, and follow-up of participants, and the primary and secondary outcomes. The trial will also inform the final health economic model to be applied in the main trial.

Trial Registration

International Standard Randomized Controlled Trial Number (ISRCTN): 99559262; http://isrctn.com/ISRCTN99559262

International Registered Report Identifier (IRRID)

DERR1-10.2196/15058

Spatial proximity between T and PD-L1 expressing cells as a prognostic biomarker for oropharyngeal squamous cell carcinoma

Background

Fulfilling the promise of cancer immunotherapy requires novel predictive biomarkers to characterise the host immune microenvironment. Deciphering the complexity of immune cell interactions requires an automated multiplex approach to histological analysis of tumour sections. We tested a new automatic approach to select tissue and quantify the frequencies of cell-cell spatial interactions occurring in the PD1/PD-L1 pathway, hypothesised to reflect immune escape in oropharyngeal squamous cell carcinoma (OPSCC).

Methods

Single sections of diagnostic biopsies from 72 OPSCC patients were stained using multiplex immunofluorescence (CD8, PD1, PD-L1, CD68). Following multispectral scanning and automated regions-of-interest selection, the Hypothesised Interaction Distribution (HID) method quantified spatial proximity between cells. Method applicability was tested by investigating the prognostic significance of co-localised cells (within 30 μm) in patients stratified by HPV status.

Results

High frequencies of proximal CD8⁺ and PD-L1⁺ (HR 2.95, p = 0.025) and PD1⁺ and PD-L1⁺ (HR 2.64, p = 0.042) cells were prognostic for poor overall survival in patients with HPV negative OPSCC (n = 31).

Conclusion

The HID method can quantify spatial interactions considered to reflect immune escape and generate prognostic information in OPSCC. The new automated approach is ready to test in additional cohorts and its applicability should be explored in research and clinical studies.

A Multicentre UK Study of Outcomes of Nasopharyngeal Carcinoma Treated With Intensity-Modulated Radiotherapy ± Chemotherapy

AIMS

To report the outcomes of nasopharyngeal carcinoma in adults across three large centres in a non-endemic region in the era of intensity-modulated radiotherapy (IMRT).

MATERIALS AND METHODS

Adult patients with nasopharyngeal carcinoma treated in three large cancer centres with IMRT ± chemotherapy with curative intent between 2009 and 2016 were identified from institutional databases. Radiotherapy was delivered with 70 Gy in 33-35 daily fractions. A univariable analysis was carried out to evaluate the relationship of patient, tumour and treatment factors with progression-free survival (PFS) and overall survival.

RESULTS

In total, 151 patients were identified with a median follow-up of 5.2 years. The median age was 52 years (range 18-85). Seventy-five per cent were of Caucasian origin; 75% had non-keratinising tumours; Epstein Barr virus status was only available in 23% of patients; 74% of patients had stage III or IV disease; 54% of patients received induction chemotherapy; 86% of patients received concurrent chemotherapy. Five-year overall survival, PFS, local disease-free survival, regional disease-free survival and distant disease-free survival were 70%, 65%, 91%, 94% and 82%, respectively. Keratinising squamous cell carcinoma, older age, worse performance status, smoking and alcohol intake were associated with inferior overall survival and PFS.

CONCLUSIONS

Local, regional and distant disease control are relatively high following IMRT ± chemotherapy in a non-endemic population. There was considerable heterogeneity in terms of radiotherapy treatment and the use of chemotherapy, encouraging the development of treatment protocols and expert peer review in non-endemic regions.

Clinical profile of the functionally selective glucocorticoid receptor agonist BI 653048 in healthy male subjects

BACKGROUND

An efficacious anti-inflammatory corticosteroid with reduced side effects has been long sought. We report the pooled results from three clinical proof-of-mechanism Phase I studies of BI 653048 in healthy subjects, a functionally selective, nonsteroidal glucocorticoid (GC).

RESEARCH DESIGN AND METHODS

Three Phase I trials were conducted: a single rising-dose study and a multiple rising-dose study to evaluate the safety, tolerability, and pharmacokinetics of BI 653048, and a multiple parallel-arm-dose study with intravenous lipopolysaccharide challenge to assess in vivo pharmacodynamics. The pharmacodynamics, efficacy, and safety of BI 653048 and prednisolone were compared.

RESULTS

Treatment with 200 mg BI 653048 was associated with a reduced expression of IL1R2, ITGB3, and SDPR versus 20 mg prednisolone; comparable levels of FKBP5, ZBTB16, and DDIT4 expression were observed. Changes in C-peptide, glucose, insulin, and cortisol were moderate compared with prednisolone. A greater reduction of osteocalcin was observed with 200 mg BI 653048 versus 20 mg prednisolone. Comparable anti-inflammatory efficacy was demonstrated for 200 mg BI 653048 and 20 mg prednisolone. BI 653048 was well tolerated in healthy subjects.

CONCLUSION

BI 653048 demonstrated the desired anti-inflammatory effects of the nonsteroidal GC; however, the undesirable side-effect profile associated with GC steroids could not be disassociated from BI 653048.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers NCT02217644, NCT02217631, and NCT02224105.

Use of a novel atlas for muscles of mastication to reduce inter observer variability in head and neck radiotherapy contouring

PURPOSE/OBJECTIVE(S)

Trismus is caused by injury to the masticatory muscles resulting from cancer or its treatment. Contouring these muscles to reduce dose and radiation related trismus can be problematic due to interobserver variability. This study aimed to evaluate the reduction in interobserver variability achievable with a new contouring atlas.

MATERIALS/METHODS

The atlas included: medial and lateral pterygoids (MP, LP), masseter (M) and temporalis (T) muscles, and the temporo-mandibular joint (TMJ). Seven clinicians delineated five paired structures on CT scans from 5 patients without the atlas. After ≥5 weeks, contouring was repeated using the atlas. Using contours generated by the clinicians on the same 5 CT scans as reference, dice similarity coefficient (DSC), mean distance-to-agreement (DTA) and centre of mass (COM) difference were compared with and without the atlas. Comparison was also performed split by training grade. Mean and standard deviation (SD) values were measured.

RESULTS

The atlas reduced interobserver variability for all structures. Mean DTA significantly improved for MP (p = 0.01), M (p < 0.01), T (p < 0.01) and TMJ (p < 0.01). Mean DTA improved using the atlas for the trainees across all muscles, with the largest reduction in variability observed for the T (4.3 ± 7.1 v 1.2 ± 0.4 mm, p = 0.06) and TMJ (2.1 ± 0.7 v 0.8 ± 0.3 mm, p < 0.01). Distance between the COM and interobserver variability reduced in all directions for MP and T.

CONCLUSION

A new atlas for contouring masticatory muscles during radiotherapy planning for head and neck cancer reduces interobserver variability and could be used as an educational tool.

Gender differences in doxorubicin pharmacology for subjects with chemosensitive cancers of young adulthood

PURPOSE

For many cancers, adolescents and young adults (AYA) have worse outcomes than for children and adults. Many factors may contribute to the AYA survival gap, including differences in biology, therapeutic intent, and adherence to therapy. It has been observed that male AYAs have poorer outcomes than females. The purpose of this work was to test the proposition that gender-related pharmacologic factors may account for a component of the AYA survival gap.

PATIENTS AND METHODS

A prospective, multi-institutional pharmacologic study of 79 patients in total with chemosensitive cancers (Ewing sarcoma, osteosarcoma and Hodgkin lymphoma) was conducted, with conventional doxorubicin treatment. Pharmacokinetic data of 13 children, 40 AYAs and 13 adults were valid for analysis. Population pharmacokinetics models were developed for doxorubicin and its metabolite doxorubicinol based on the data created in this study. Consequently, model-based analysis was conducted to investigate the relevant topics.

RESULTS

The clearance of doxorubicinol (normalized to body surface area), the main active metabolite of doxorubicin, appears faster in male AYAs than female (p = 0.04, 95% CI 0.1-3.9 L/h). The exposure of doxorubicinol (normalized to dose) is lower in male AYA than female (p = 0.03, 95% CI - 0.005 to - 0.0002 h/L). These might be correlated to the observed difference on nadir neutrophil count between male AYA and female (p = 0.027, 95% CI 0.09-1.4).

CONCLUSION

Gender-related differences in doxorubicin pharmacology may account for worse outcomes for male AYAs with chemosensitive cancers compared to females. These findings may reduce the AYA survival gap compared to other age groups.

Prospective evaluation of relationships between radiotherapy dose to masticatory apparatus and trismus

AIMS

This feasibility study aimed to identify relationships between radiation doses to the masticatory apparatus as a combined block or as individual subunits with changes in trismus following radiotherapy.

MATERIAL AND METHODS

Twenty patients from a single center were recruited prospectively as part of a randomized trial comparing proactive exercises in the management of trismus. Patients with stage III/IV oral cavity or oropharyngeal squamous cell cancers received intensity-modulated radiotherapy with concurrent systemic therapy. All patients had trismus prior to radiotherapy. Maximal inter-incisor distance (MID) was measured pre- and 6 months from the start of radiotherapy. Bilateral muscles of mastication: medial and lateral pterygoids (MP and LP), masseters (M), temporalis (T), temporomandibular joint (TMJ) were contoured on CT images. The block comprised all muscles excluding the TMJ below the orbital floor. Mean dose, equivalent uniform dose (EUD) and V35-V60 Gy were compared with change in MID.

RESULTS

In six patients, the MID deteriorated at 6 months from the start of radiotherapy compared with 14 whose MID improved. No significant association was observed between age, gender, smoking, alcohol status, exercise compliance, cisplatin, tumor site, stage, V35-V60 Gy or EUD with change in MID. A clinical outlier was excluded. Without the outlier (n = 19), a significant association was seen between mean dose and change in MID at 6 months for the ipsilateral block (p = .01), LP (p = .04) and M (p < .01). All patients where trismus deteriorated at 6 months received mean doses >40 Gy to the block.

CONCLUSION

Higher mean radiation doses to the ipsilateral block, LP and M were significantly associated with deterioration in trismus. Limiting dose to these structures to ≤40 Gy for tumors not invading the masticatory muscles may improve treatment-related sequelae. The ipsilateral block, LP and M should be studied further as possible alternative avoidance structures in radiotherapy treatment planning.