Prognosis of oral epithelial dysplasia in individuals with and without oral lichen planus

OBJECTIVES

To investigate the role of oral lichen planus (OLP) on the long-term prognosis of oral epithelial dysplasia (OED).

METHODS

Retrospective single-centre cohort study using the 2007-2019 database of the Head and Neck Cancer and Oral Medicine units of University College London Hospital. The exposure of interest was the presence of OLP, and the prognostic outcomes included the development of new primary episodes of OED, progression to malignancy and mortality. Cox proportional hazard and Poisson regression models were performed.

RESULTS

A total of 299 patients, of whom 144 had OED arising on the background of OLP (OLP/OED) and 155 had OED without underlying OLP (non-OLP/OED), were included. A pre-existing diagnosis of OLP was significantly associated with a twofold increased risk of subsequent primary OED events (HR = 2.02, p = 0.04), which also developed faster (1.46 vs. 2.96 years, p = 0.04) and with more involvement of non-cancer-prone sites (p = 0.001) than in the non-OLP/OED group. There was no difference between groups in the progression to malignancy or mortality.

CONCLUSIONS

Oral lichen planus/OED patients are at higher risk of multiple episodes of primary OED, which can develop faster and at non-cancer-prone sites as compared to non-OLP/OED individuals. Further research is needed to clarify the effects of OLP upon progression to OSCC and mortality.

Incidental Thyroid Tissue in Sentinel Nodes From Oral Squamous Cell Carcinoma

OBJECTIVE

Sentinel node biopsy (SNB) is a surgical staging test in which sentinel nodes (SNs) undergo intensive histological analysis. SNB diagnoses early cancer spread, but can also reveal unexpected findings within the SNs. We review cases of incidental thyroid cells (TC) found in SNs from patients with oral squamous cell carcinoma (OSCC) to assess the prevalence of TC, and the clinical significance of these.

METHODS

Multicenter retrospective review of SNB performed for cT1-T2N0 OSCC. Incidental TC were identified by TTF-1 or thyroglobulin positivity. Anatomical location of nodes containing TC, TC morphology, and ongoing management/follow up of this incidental finding was recorded. Neck dissections performed during the same period were reviewed to establish the expected incidence of TC in neck nodes without serial sectioning analysis.

RESULTS

278 SNB cases were reviewed. Ten procedures detected TC in nine patients (10/278, 3.6%). During the same time period 725 neck dissections were performed, six containing TCs (6/725, 0.8%). One patient underwent SNB twice with TC identified on both occasions. Three patients had both OSCC metastasis and thyroid cells. All SNB patients with TC identified underwent thyroid USS with no primary tumours identified. Three patients underwent thyroidectomy, in all cases no primary thyroid tumour was found.

CONCLUSION

Prevalence of incidental TC in SNs appears to be higher than that reported in neck dissections, these are not likely to be clinically relevant and can be managed on a conservative basis in the absence of clear metastatic features.

LEVEL OF EVIDENCE

Multicentre retrospective cohort study, 3 Laryngoscope, 134:1278-1281, 2024.

A training tool for clinicians in segmenting medical images to make 3D models

Introduction

3D models produced from medical imaging can be used to plan treatment, design prosthesis, teach and for communication. Despite the clinical benefit, few clinicians have experience of how 3D models are produced.This is the first study evaluating a training tool to teach clinicians to produce 3D models and reporting the perceived impact on their clinical practice.

Method

Following ethical approval, 10 clinicians completed a bespoke training tool, comprising written and video material alongside online support. Each clinician and 2 technicians (included as control) were sent 3 CT scans and asked to produce 6 fibula 3D models using an open-source software (3Dslicer). The produced models were compared to those produced by the technicians using Hausdorff distance calculation. Thematic analysis was used to study the post-intervention questionnaire.

Results

The mean Hausdorff distance between the final model produced by the clinicians and technicians was 0.65mm SD0.54mm. The first model made by clinicians took a mean time of 1hr 25mins and the final model took 16:04mins (5:00-46:00mins). 100% of learners reported finding the training tool useful and will employ it in future practice.

Discussion

The training tool described in this paper is able to successfully train clinicians to produce fibula models from CT scans. Learners were able to produce comparable models to technicians within an acceptable timeframe. This does not replace technicians. However, the learners perceived this training will allow them to use this technology in more cases, with appropriate case selection and they appreciate the limits of this technology.

Systematic review and meta-analysis of occult contralateral nodal metastases in patients with oropharyngeal squamous carcinoma undergoing elective neck dissection

A systematic review and meta-analysis was conducted to evaluate the occult contralateral nodal metastases (OCM) in patients undergoing bilateral neck dissection for surgically treated oropharyngeal squamous cell carcinoma (OPSCC). Following PRISMA guidelines, MEDLINE, Embase and Cochrane Controlled Register of Trials databases were searched for observational and experimental studies until March 2021. Search yielded 175 articles, of which 13 were included. Overall, OCM were seen in 9.8% of patients (95% CI: [5.7, 16.4], 839 patients, 12 studies, I² 65%). For ipsilateral cN0 necks, the OCM rate was 1.7% (95% CI: [0.1, 22.4], 150 patients, 8 studies, I² 0%) and for cN + necks the OCM rate was 9.8% (95% CI: [4.4, 20.3], 429 patients, 8 studies, I² 72%). Occult contralateral nodal metastases are uncommon in OPSCC patients with clinico-radiologically negative ipsilateral necks. Occult rates are higher in the contralateral neck when the ipsilateral neck is clinico-radiologically node positive.

Academic Training in Oral and Maxillofacial Surgery - when and how to enter the pathway

Entering into surgical academia can seem a daunting prospect for an oral and maxillofacial surgery (OMFS) trainee. However, the streamlining of academic training by the NIHR to create the integrated academic training (IAT) pathway has simplified academic training and more clearly defined academic positions and entry points for trainees. In this article we review the current NIHR IAT pathway and the various grades and entry points available to OMF surgeons, both pre- and post-doctoral. We highlight the unique challenges facing OMF trainees and provide advice and insight from both junior and senior OMFS academics. Finally, we focus on the planning and application for a doctoral research fellowship - discussing funding streams available to OMF surgeons.

Systematic review of techniques used to validate the registration of augmented-reality images using a head-mounted device to navigate surgery

Augmented-reality (AR) head-mounted devices (HMD) allow the wearer to have digital images superposed on to their field of vision. They are being used to superpose annotations on to the surgical field akin to a navigation system. This review examines published validation studies on HMD-AR systems, their reported protocols, and outcomes. The aim was to establish commonalities and an acceptable registration outcome. Multiple databases were systematically searched for relevant articles between January 2015 and January 2021. Studies that examined the registration of AR content using a HMD to guide surgery were eligible for inclusion. The country of origin, year of publication, medical specialty, HMD device, software, and method of registration, were recorded. A meta-analysis of the mean registration error was conducted. A total of 4784 papers were identified, of which 23 met the inclusion criteria. They included studies using HoloLens (Microsoft) (n = 22) and nVisor ST60 (NVIS Inc) (n = 1). Sixty-six per cent of studies were in hard tissue specialties. Eleven studies reported registration errors using pattern markers (mean (SD) 2.6 (1.8) mm), and four reported registration errors using surface markers (mean (SD) 3.8 (3.7) mm). Three studies reported registration errors using manual alignment (mean (SD) 2.2 (1.3) mm). The majority of studies in this review used in-house software with a variety of registration methods and reported errors. The mean registration error calculated in this study can be considered as a minimum acceptable standard. It should be taken into consideration when procedural applications are selected.

Intraoperative Positioning in Maxillofacial Trauma Patients With Cervical Spine Injury - Is It Safe? Radiological Simulation in a Healthy Volunteer

Study Design

Observational.

Objective

To investigate the effects on the cervical spine of positioning patients for maxillofacial procedures by simulating intraoperative positions for common maxillofacial procedures.

Methods

Magnetic resonance imaging was used to assess the effects of head position in common intraoperative configurations - neutral (anterior mandible position), extended (tracheostomy position) and laterally rotated (mandibular condyle position) on the C-spine of a healthy volunteer.

Results

In the tracheostomy position, maximal movement occurred in the sagittal plane between the cervico-occipital junction and C4-C5, as well as at the cervico-thoracic junction. Minimal movement occurred at C2 (on C3), C5 (on C6) and C6 (on C7). In the mandibular condyle position, C-spine movements occurred in both rotational and sagittal planes. Maximal movement occurred above the level of C4, concentrated at atlanto-occipital and atlanto-axial (C1-2) joints.

Conclusions

Neck extension is likely to be relatively safe in injuries that are stable in flexion and extension, such as odontoid peg fracture and fractures between C5 and C7. Head rotation is likely to be relatively safe in fractures below C4, as well as vertebral body fractures, and laminar fractures without disc disruption. Early dialogue with the neurosurgical team remains a central tenet of safe management of patients with combined maxillofacial and C-spine injuries.

Machine learning methods applied to risk adjustment of cumulative sum chart methodology to audit free flap outcomes after head and neck surgery

We describe a risk adjustment algorithm to benchmark and report free flap failure rates after immediate reconstruction of head and neck defects. A dataset of surgical care episodes for curative surgery for head and neck cancer and immediate reconstruction (n = 1593) was compiled from multiple NHS hospitals (n = 8). The outcome variable was complete flap failure. Classification models using preoperative patient demographic data, operation data, functional status data and tumour stage data, were built. Machine learning processes are described to model free flap failure. Overall complete flap failure was uncommon (4.7%) with a non-statistical difference seen between hospitals. The champion predictive model had acceptable discrimination (AUROC 0.66). This model was used to risk-adjust cumulative sum (CuSUM) charts. The use of CuSUM charts is a viable way to monitor in a 'Live Dashboard' this quality metric as part of the quality outcomes in oral and maxillofacial surgery audit.

Precision surgery: the role of intra-operative real-time image guidance - outcomes from a multidisciplinary European consensus conference

Developments within the field of image-guided surgery are ever expanding, driven by collective involvement of clinicians, researchers, and industry. While the general conception of the potential of image-guided surgery is to improve surgical outcome, the specific motives and goals that drive can differ between the different expert groups. To establish the current and future role of intra-operative image guidance within the field of image-guided surgery a Delphi consensus survey was conducted during the 2^nd European Congress on Image-guided surgery. This multidisciplinary survey included questions on the conceptual potential and clinical value of image-guided surgery and was aimed at defining specific areas of research and development in the field in order to stimulate further advances towards precision surgery. Obtained results based on questionnaires filled in by 56 panel experts (clinicians: N=30, researchers: N=20 and industry: N=6) were discussed during a dedicated expert discussion session during the conference. The outcome of this Delphi consensus is indicative of the potential improvements offered by image-guided surgery and of the need for further research in this emerging field, that can be enriched by the identification of reliable molecular targets.

Centralised pathology service for sentinel node biopsy in oral cavity cancer: The Southeast England Consortium experience

BACKGROUND

Sentinel lymph node biopsy is an increasingly recognised option for accurate staging and subsequent management of the clinically negative neck in early stage oral cavity squamous cell carcinoma. However, the technique is currently underused due to several logistic constraints including increased burden on pathology services. Here, we describe the feasibility of an outsourced centralised pathology processing and reporting service for sentinel lymph node biopsies in oral cavity squamous cell carcinoma.

PATIENTS AND METHODS

The Southeast England Consortium comprises four surgical centres utilising a central pathology service. Consecutive cases between January 2016 and February 2020 were retrospectively evaluated for survival outcomes and laboratory turnaround times.

RESULTS

Twenty-eight per cent from a cohort of 139 patients had positive sentinel nodes. There was a trend towards greater overall, disease-free and disease-specific survival (OS, DFS and DSS, respectively) in sentinel node negative compared to sentinel node positive patients, but these differences were not statistically significant. The sensitivity, negative predictive value and false negative rate were 92.8%, 97.0% and 6.8%, respectively. The mean and mode laboratory TAT were 5 and 4 working days, respectively.

CONCLUSION

An outsourced centralised pathology service is a feasible option to widen the availability of sentinel node biopsy in oral cavity squamous cell carcinoma.

Single-photon emission computed tomography (SPECT/CT) images of sentinel node distribution in oral cancer

This audit describes the lymphatic flow from oral tumours seen on single-photon emission computed tomography (SPECT/CT) to help sentinel node (SN) identification. A total of 95 consecutive sentinel node biopsies (SNB) were taken between 2010 and 2019. Eligibility criteria for SNB were patients over 18 years of age with a T₁-T₂ oral or oropharyngeal squamous cell carcinoma and an N₀ neck. SNs collect at high-frequency sites irrespective of the primary tumour (22.7% level Ib; 64.8% levels II/III; and 7.6% level IV), but with individual variation. Radiotracer activity did not influence the number of nodes identified, and metastatic deposits were found in the hottest nodes. SNs occur at the same high-frequency locations in the neck, so familiarity with anatomical detail may reduce false-negative results.

Novel double injection technique for sentinel lymph node biopsy in oral cancer

The development of new lymphatic tracers and the advancement of hybrid tracers, such as indocyanine green (ICG)-Nanocoll (GE Healthcare), represent an exciting step in the future of sentinel lymph node biopsy (SLNB). These tracers aim to improve our ability to detect sentinel lymph nodes by enhancing their localisation. The aim of this study was to assess the performance of a novel dual tracer, double injection technique of ICG-'cold'-Nanocoll and radiolabelled Nanocoll, in SLNB for early-stage oral cancer. A double injection technique was performed first using ^99mTc-Nancoll prior to sentinel node imaging followed by ICG-'cold'-Nanocoll injection in theatre. Analysis involved examination of the number, labelling, and location of the nodes harvested, sentinel node status, survival analysis, false negative rate, and complications associated with use of the technique. ICG 'cold' Nanocoll results showed concordance of fluorescence and radioactivity detection in 74 nodes in 24 patients. Most importantly, all nodes found positive for metastasis (6 nodes) were discovered to be both 'hot' and fluorescent; 74 nodes removed were both 'hot' and fluorescent, eight fluorescent only and six 'hot' only. Our results indicate that two sets of tracer injections given at two different time points will flow to the same sentinel nodes. This double labelling increased our confidence that the retrieved node was a sentinel node.

Serial step sections at narrow intervals with immunohistochemistry are required for accurate histological assessment of sentinel lymph node biopsy in oral squamous cell carcinoma

BACKGROUND

Sentinel lymph node (SLN) biopsy is an accurate staging modality in early oral squamous cell carcinoma (OSCC), but its accuracy relies on labor-intensive histopathology protocols. We sought to determine whether serial step sections with immunohistochemistry (SSSIHC) at narrow intervals of the entire SLN are required to accurately exclude metastasis.

METHODS

Consecutive SLN biopsies over a 13-year period were retrospectively evaluated. If the index section was negative for carcinoma, the entire SLN was subjected to SSSIHC at 150 μm intervals. The first section level and total number of section levels to contain carcinoma were recorded.

RESULTS

One hundred and eighteen SLN+ from 90 patients were included. SSSIHC upstaged the nodal status in 19.5% of patients. Metastasis was identified in 16.7% and 10.2% beyond section levels 4 and 6, respectively. Among SLNs requiring SSSIHC, 47.5% contained carcinoma in a single section level.

CONCLUSION

SSSIHC of the entire SLN at 150 μm intervals are required to identify occult metastasis in OSCC.

PET- and SPECT-based navigation strategies to advance procedural accuracy in interventional radiology and image-guided surgery

INTRODUCTION

Nuclear medicine has a crucial role in interventional strategies where a combination between the increasing use of targeted radiotracers and intraprocedural detection modalities enable novel, but often complex, targeted procedures in both the fields of interventional radiology and surgery. 3D navigation approaches could assist the interventional radiologist or surgeon in such complex procedures.

EVIDENCE ACQUISITION

This review aimed to provide a comprehensive overview of the current application of computer-assisted navigation strategies based on nuclear imaging to assist in interventional radiology and image-guided surgery. This work starts with a brief overview of the typical navigation workflow from a technical perspective, which is followed by the different clinical applications organized based on their anatomical organ of interest.

EVIDENCE SYNTHESIS

Although many studies have proven the feasibility of PET- and SPECT-based navigation strategies for various clinical applications in both interventional radiology and surgery, the strategies are spread widely in both navigation workflows and clinical indications, evaluated in small patient groups. Hence, no golden standard has yet been established.

CONCLUSIONS

Despite that the clinical outcome is yet to be determined in large patient cohorts, navigation seems to be a promising technology to translate nuclear medicine findings, provided by PET- and SPECT-based molecular imaging, to the intervention and operating room. Interventional Nuclear Medicine (iNM) has an exciting future to come using both PET- and SPECT-based navigation.

Neck failure following pathologically node-negative neck dissection (pN0) in oral squamous cell carcinoma: a systematic review and meta-analysis

Due to the risk of occult cervical metastasis, elective neck dissection (END) is recommended in the management of patients with early oral cavity squamous cell carcinoma (OSCC) and a clinically node-negative (cN0) neck. This paper presents a systematic review and meta-analysis of studies that recorded isolated regional recurrence (RR) in the pathologically node-negative neck dissection (pN0) neck following END in order to quantify the failure rate. Pubmed and Ovid databases were systematically searched for relevant articles published between January 2009 and January 2019. Studies reporting RR following END in patients with OSCC who had no pathological evidence of lymph node metastasis were eligible for inclusion in this meta-analysis. In addition, a selection of large head and neck units were invited to submit unpublished data. Search criteria produced a list of 5448 papers, of which 18 studies met the inclusion criteria. Three institutions contributed unpublished data. This included a total of 4824 patients with median follow-up of 34 months (2.8 years). Eight datasets included patients staged T1-T4 with RR 17.3% (469/2711), 13 datasets included patients staged T1-T2 with RR 7.5% (158/2113). Overall across all 21 studies, isolated neck recurrence was identified in 627 cases giving a RR of 13.0% (627/4824) on meta-analysis. Understanding the therapeutic effectiveness of END provides context for evaluation of clinical management of the cN0 in these patients. A pathologically negative neck does not guarantee against future recurrence.

Do we have a robust method for preoperative tumour depth assessment for oral cavity tumours with clinically negative necks?

Tumour depth is an important prognostic factor in head and neck cancer and has recently been included in the eighth edition of the Union for International Cancer Control TNM classification of malignant tumours for oral squamous cell carcinoma (OSCC). It is important to appraise the accuracy of depth assessments; however, there is little current evidence in the literature. Accurate depth assessment is particularly pertinent in cT1-T2N0 OSCC where it may influence neck management. A retrospective study was performed at two tertiary referral centres, in which surgically treated patients with cT1-T4N0 OSCC were audited. Preoperative tumour depth assessments from multimodality radiological staging scans were compared with the final histopathological depth. The predictive accuracy of intraoral ultrasound (IOUS), computed tomography (CT), and magnetic resonance imaging (MRI) for tumour depth was evaluated. Accuracy to within 3mm of the histopathological depth was seen in 56.7% of MRI scans and 57.1% of CT scans. IOUS appeared to have superior prediction, with 78.2% of measurements within 3mm. Over one third of CT and MRI imaging failed to detect a lesion; IOUS scans detected the lesions in all of these case. In conclusion, the reliability of preoperative imaging assessment of tumour depth should be considered when recommending treatment.

Surgical consensus guidelines on sentinel node biopsy (SNB) in patients with oral cancer

BACKGROUND

The eighth international symposium for sentinel node biopsy (SNB) in head and neck cancer was held in 2018. This consensus conference aimed to deliver current multidisciplinary guidelines. This document focuses on the surgical aspects of SNB for oral cancer.

METHOD

Invited expert faculty selected topics requiring guidelines. Topics were reviewed and evidence evaluated where available. Data were presented at the consensus meeting, with live debate from panels comprising expert, nonexpert, and patient representatives followed by voting to assess the level of support for proposed recommendations. Evidence review, debate, and voting results were all considered in constructing these guidelines.

RESULTS/CONCLUSION

A range of topics were considered, from patient selection to surgical technique and follow-up schedule. Consensus was not achieved in all areas, highlighting potential issues that would benefit from prospective studies. Nevertheless these guidelines represent an up-to-date pragmatic recommendation based on current evidence and expert opinion.

The EANM practical guidelines for sentinel lymph node localisation in oral cavity squamous cell carcinoma

Purpose

Sentinel lymph node biopsy is an essential staging tool in patients with clinically localized oral cavity squamous cell carcinoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery, and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with early N0 oral cavity squamous cell carcinoma.

Methods

These practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) and the International Atomic Energy Agency (IAEA) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, and national nuclear medicine societies. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI).

These guidelines, together with another two focused on Surgery and Pathology (and published in specialised journals), are part of the synergistic efforts developed in preparation for the “2018 Sentinel Node Biopsy in Head and Neck Consensus Conference”.

Conclusion

The present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of early N0 oral cavity squamous cell carcinoma patients.

CeO2-x nanorods with intrinsic urease-like activity

The large-scale production and ecotoxicity of urea make its removal from wastewater a health and environmental challenge. Whereas the industrial removal of urea relies on hydrolysis at elevated temperatures and high pressure, nature solves the urea disposal problem with the enzyme urease under ambient conditions. We show that CeO2-x nanorods (NRs) act as the first and efficient green urease mimic that catalyzes the hydrolysis of urea under ambient conditions with an activity (kcat = 9.58 × 101 s-1) about one order of magnitude lower than that of the native jack bean urease. The surface properties of CeO2-x NRs were probed by varying the Ce4+/Ce3+ ratio through La doping. Although La substitution increased the number of surface defects, the reduced number of Ce4+ sites with higher Lewis acidity led to a slight decrease of their catalytic activity. CeO2-x NRs are stable against pH changes and even to the presence of transition metal ions like Cu2+, one of the strongest urease inhibitors. The low costs and environmental compatibility make CeO2-x NRs a green urease substitute that may be applied in polymer membranes for water processing or filters for the waste water reclamation. The biomimicry approach allows the application of CeO2-x NRs as functional enzyme mimics where the use of native or recombinant enzyme is hampered because of its costs or operational stability.

ARTICULATION AND BACKSIDE WEAR ANALYSIS AFTER LONG-TERM IN VITRO WEAR SIMULATION OF VITAMIN E STABILIZED POLYETHYLENE ACETABULAR LINERS WITH A PRESS-FIT LOCKING MECHANISM

A previous retrieval study analyzed the backside wear of short-term implanted liners against in vitro tested liners of similar life in service and showed comparable results among both groups, with no significant backside wear due to micro-motion.

The purpose — to obtain a picture of the overall wear (articulation and backside surfaces) of 0.1% vitamin e blended polyethylene liners, with a locking mechanism based on a press-fit cone in combination with a rough titanium conical inner surface in the fixation area, under a 20 million cycles hip wear simulation.

Materials and Methods. A semi-quantitative method was used in order to assess the damage on the backside of the liners and a 3d measuring machine to assess the creep and wear at the articulation surface.

Results. The total average backside wear score was 22.00±2.59 from a maximum total score of 147 after 5 million cycles (mc), increased to 31.92±5.57 after 10 mc, but showed no further increment after 15 and 20 mc. The reference liners (subjected only to axial load) showed similar wear scores and modes as the liners under wear simulation (axial load and movement). Small scratches produced during insertion and removal were clearly seen at the rim (fixation) area and no considerable abrasion was observed. The machining marks on the convex surface were always visible. Regarding the articulation surface, a steady state wear rate of 7 µm/year was measured.

Conlusion. These results determined that most of the backside wear produced on the liners occurred during their insertion and removal rather than during their life in service. Moreover, the wear at the articulation surface was similar to that seen in vivo at short- and mid-term on highly cross-linked polyethylene liners with and without vitamin e content.

[Prevalence of sleep-related breathing disorders of inpatients with psychiatric disorders]

BACKGROUND

Sleep-related breathing disorders seriously impair well-being and increase the risk for relevant somatic and psychiatric disorders. Moreover, risk factors for sleep-related breathing disorders are highly prevalent in psychiatric patients. The aim of this study was for the first time in Germany to study the prevalence of obstructive sleep apnea syndrome (OSAS) as the most common form of sleep-related breathing disorder in patients with psychiatric disorders.

METHODS

In 10 psychiatric hospitals in Germany and 1 hospital in Switzerland, a total of 249 inpatients underwent an 8‑channel sleep polygraphy to investigate the prevalence of sleep apnea in this group of patients.

RESULTS

With a conspicuous screening result of 23.7% of the subjects, a high prevalence of sleep-related breathing disorders was found to occur among this group of patients. Male gender, higher age and high body mass index (BMI) were identified as positive risk factors for the detection of OSAS.

DISCUSSION

The high prevalence indicates that sleep apnea is a common sleep disorder among psychiatric patients. Although OSAS can lead to substantial disorders of the mental state and when untreated is accompanied by serious somatic health problems, screening procedures are not part of the routine work-up in psychiatric hospitals; therefore, sleep apnea is presumably underdiagnosed in psychiatric patients. In view of the results of this and previous studies, this topic complex should be the subject of further research studies.

Micro-CT and micro-FE analysis of pedicle screw fixation under different loading conditions

Anchorage of pedicle screw instrumentation in the elderly spine with poor bone quality remains challenging. In this study, micro finite element (µFE) models were used to assess the specific influence of screw design and the relative contribution of local bone density to fixation mechanics. These were created from micro computer tomography (µCT) scans of vertebras implanted with two types of pedicle screws, including a full region-or-interest of 10 mm radius around each screw, as well as submodels for the pedicle and inner trabecular bone of the vertebral body. The local bone volume fraction (BV/TV) calculated from the µCT scans around different regions of the screw (pedicle, inner trabecular region of the vertebral body) were then related to the predicted stiffness in simulated pull-out tests as well as to the experimental pull-out and torsional fixation properties mechanically measured on the corresponding specimens. Results show that predicted stiffness correlated excellently with experimental pull-out strength (R² > 0.92, p < .043), better than regional BV/TV alone (R2 = 0.79, p = .003). They also show that correlations between fixation properties and BV/TV were increased when accounting only for the pedicle zone (R² = 0.66-0.94, p ≤  .032), but with weaker correlations for torsional loads (R² < 0.10). Our analyses highlight the role of local density in the pedicle zone on the fixation stiffness and strength of pedicle screws when pull-out loads are involved, but that local apparent bone density alone may not be sufficient to explain resistance in torsion.

Sentinel lymph node biopsy for oral squamous cell carcinoma. Where are we now?

Recent data have confirmed that elective surgical management of the cN0 neck improves survival in patients with early (T1-T2) oral squamous cell carcinoma (SCC), and is better than watchful waiting. However, elective neck dissection (END) may not always be necessary. Sentinel node biopsy (SNB), which is a reliable staging test for patients with early disease and a radiologically N0 neck, can detect occult metastases with a sensitivity of 86%-94%. Patients with no sign of metastases on SNB could avoid neck dissection, and individual treatment should reduce both morbidity and cost. Currently, SNB for oral SCC is available at a limited number of centres in the UK, but this is likely to change as national guidelines have recommended that it is incorporated into the standard treatment pathway. It is therefore important to understand the current evidence that supports its use, its limitations and related controversies, and to plan for a validated training programme.

Augmented reality visualization in head and neck surgery: an overview of recent findings in sentinel node biopsy and future perspectives

"Augmented reality visualisation", in which the site of an operation is merged with computer-generated graphics, provides a way to view the relevant part of the patient's body in better detail. We describe its role in relation to sentinel lymph node biopsy (SLNB), current advancements, and future directions in the excision of tumours in early-stage cancers of the head and neck.

Sentinel European Node Trial (SENT): 3-year results of sentinel node biopsy in oral cancer

PURPOSE

Optimum management of the N0 neck is unresolved in oral cancer. Sentinel node biopsy (SNB) can reliably detect microscopic lymph node metastasis. The object of this study was to establish whether the technique was both reliable in staging the N0 neck and a safe oncological procedure in patients with early-stage oral squamous cell carcinoma.

METHODS

An European Organisation for Research and Treatment of Cancer-approved prospective, observational study commenced in 2005. Fourteen European centres recruited 415 patients with radiologically staged T1-T2N0 squamous cell carcinoma. SNB was undertaken with an average of 3.2 nodes removed per patient. Patients were excluded if the sentinel node (SN) could not be identified. A positive SN led to a neck dissection within 3 weeks. Analysis was performed at 3-year follow-up.

RESULTS

An SN was found in 99.5% of cases. Positive SNs were found in 23% (94 in 415). A false-negative result occurred in 14% (15 in 109) of patients, of whom eight were subsequently rescued by salvage therapy. Recurrence after a positive SNB and subsequent neck dissection occurred in 22 patients, of which 16 (73%) were in the neck and just six patients were rescued. Only minor complications (3%) were reported following SNB. Disease-specific survival was 94%. The sensitivity of SNB was 86% and the negative predictive value 95%.

CONCLUSION

These data show that SNB is a reliable and safe oncological technique for staging the clinically N0 neck in patients with T1 and T2 oral cancer. EORTC Protocol 24021: Sentinel Node Biopsy in the Management of Oral and Oropharyngeal Squamous Cell Carcinoma.

Energy harvesting for active implants: powering a ruminal pH-monitoring system

Energy harvesting is a feasible method to prolong service life of implanted devices. We present a thermal energy harvesting approach for a ruminal pH-monitoring probe in cattle. Thermoelectric generators utilize the temperature gradient between the probe and the ruminal fluid during water intake. The in vivo experiment yielded a maximum electric power of 32 μW.

Prognostic significance of neuroepithelial transforming gene 1 in adenocarcinoma of the oesophagogastric junction

Background

Neuroepithelial transforming gene 1 (NET1) mediates tumour invasion and metastasis in a number of cancers, including gastric adenocarcinoma. It is an indicator of poor prognosis in breast cancer and glioma. This study examined NET1 expression and its prognostic significance in patients with adenocarcinoma of the oesophagogastric junction (AOG).

Methods

NET1 expression was measured by immunohistochemistry in a tissue microarray, constructed from biobanked tissue collected over a 10-year interval, and linked to a prospectively maintained clinical database.

Results

Using the Siewert classification for AOG, type I tumours expressed significantly higher levels of NET1, with lowest expression in type III and intermediate levels in type II (P = 0·001). In patients with AOG type III, NET1-positive patients were more likely to be female (P = 0·043), have advanced stage cancer (P = 0.035), had a higher number of transmural cancers (P = 0·006) and had a significantly higher median number of positive lymph nodes (P = 0·029). In this subgroup, NET1-positive patients had worse median overall (15 versus 23 months; P = 0·025) and disease-free (11 versus 36 per cent; P = 0·025) survival compared with NET1-negative patients.

Conclusion

Although existing data show differences in clinical and prognostic indices across AOG subtypes, there are no studies showing differences in tumour biology. These data suggest NET1, a known mediator of an aggressive tumour phenotype in a number of gastrointestinal cancers, is expressed differentially across AOG subtypes and may be of prognostic significance in the clinical management of this condition.