Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Absence of atrial fibrillation in the blanking period following cryoballoon pulmonary vein isolation – does it always portend a good prognosis?

Background

Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for ablation in patients with paroxysmal and persistent atrial fibrillation (PAF, PeAF). Freedom from AF in the blanking period (BP), conventionally defined as the first 3-months post-PVI, has been associated with the best long-term outcomes. However, the influence of antiarrhythmic drugs (AADs) during the BP on long-term outcomes is not well understood.

Objective

To compare long-term outcomes between patients who were and were not on an AAD prior to ablation and remained free from AF during the 3-month BP post CB PVI.

Methods

We enrolled consecutive AF patients undergoing CB PVI; all pts had an implantable loop recorder (ILR). No patient had any AF in the first 90 days post CB PVI. We divided the patients into three groups: (1) never had exposure to an AAD; (2) were intolerant to/failed AAD and thus were not taking an AAD at time of ablation; and (3) were on AAD at time of ablation. In the latter group, every effort was made to stop the AAD before the end of the BP.

Results

The cohort included 96 pts (66±10 years; 60 [63%] male; 55 [57%] PAF; CHA2DS2-VASc 2.5±1.4). There were 23 (24%) patients in group 1, 13 (14%) patients in group 2, and 60 (63%) pts in group 3. Patients in group 3 were more likely to have PeAF; AADs were stopped at a median of 36 days IQR (27, 91) in this group. Patients were followed for 1-year during which time 28 (29%) patients had recurrent AF (despite having no AF during the BP). The best outcome was seen in patients who never used an AAD; the worst outcome was seen in patients who were on an AAD at time of ablation (Figure 1).

Conclusion

Our data show that absence of AF during a 3-month post CB PVI BP alone does not guarantee good-long term outcome, unless the patient was never treated with an AAD. In contrast, in patients ablated while taking an AAD, recurrent AF was observed in 37% even though they were completely AF-free during the BP.

Funding Acknowledgement

Type of funding sources: None.

Recurrence of atrial fibrillation following pulmonary vein isolation: impact of body mass index on one- and three-year outcomes

Background

Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for ablation in patients with paroxysmal and persistent atrial fibrillation (PAF, PeAF). However, there are a paucity of data about the impact of body mass index (BMI) on one-year and longer-term outcomes following ablation.

Objective

To objectively understand the impact of BMI on outcomes following CB PVI.

Methods

We enrolled consecutive AF patients undergoing CB PVI; all patients had an implantable loop recorder (ILR), which transmitted data wirelessly daily. We assessed AF recurrences after excluding an initial 3-month post-ablation blanking period.

Results

The cohort included 222 pts (66±9 years; 143 [64%] male; 120 [54%] PAF; CHA2DS2-VASc 2.6±1.6). The mean BMI was 30±5. Patients were followed for 763±347 days, during which time 50% and 68% had recurrent AF 1- and 3-years post ablation. We divided the cohort based on the mean BMI into 2 groups: BMI <30 and BMI >30. Heavier patients were younger and more likely to have PeAF. Over 1-year of follow-up, patients with a BMI <30 had similar likelihood of being free of AF to patients with a BMI >30 (46% vs, 56%, p=0.0.097, Figure 1, left). However, as patients were followed for 3-years, freedom from AF was significantly higher in patients with a BMI <30 (59% vs. 81% in BMI >30, p=0.002, Figure 1, right).

Conclusions

Our data show that although patients had similar outcomes 1-year post-ablation, during longer-term follow-up patients with a BMI >30 had a much worse outcome. Our study uniquely offers objective (using an ILR) assessment of the impact of BMI on long-term outcomes following CB PVI (homogenous ablation strategy). These data highlight the need to identify strategies to improve outcomes in obese patients.

Funding Acknowledgement

Type of funding sources: None.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

The impact of atrial fibrillation burden early post cryoballoon pulmonary vein isolation on long-term freedom from recurrent atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. A three-month blanking period (BP) is commonly used in clinical trials and practice. Early recurrence of AF portends worse ablation long-term outcome; however, the utility of using AF burden (AFB) early post cryoballoon (CB) PVI to predict long-term outcome is unknown.

Purpose

To determine, using ECG data acquired by an implantable loop recorder (ILR), the relationship between post-ablation AFB and long-term freedom from AF.

Methods

We enrolled consecutive patients with AF who had CB PVI and an ILR. We determined the monthly AFB for the first 3 months post CB PVI and assessed the relationship between AFB and 1-year freedom from AF. We defined 4 distinct AFB groups: (1) 0%, (2) > 0-0.1%, (3) > 0.1-0.5%, and (4) > 0.5%.

Results

There were 210 patients (66 ± 9 years; 138 [66%] male; 116 [55%] paroxysmal AF; CHA2DS2-VASc 2.5 ± 1.6). Following a 3-month BP, 101 (48%) patients had a recurrence of AF at 160 ± 86 days post-ablation. An AFB of > 0% over the first 3 months predicted AF recurrence (p < 0.0001, Figure 1). Patients with > 0.5% AF burden after 1st month and any AF after 2nd month post CB PVI have a very high long-term AF recurrence rate (Figure 2).

Conclusion

The best long term outcome post CB PVI is seen in pts who have no AF in the first 3 months post ablation. An AFB >0.5% after the first month and any AF after the second month portend ablation failure. These data define a clinical utility of using AFB to risk stratify patients post CB PVI.

Yearly incidence and pattern of very late recurrence of atrial fibrillation as detected by continuous electrocardiographic monitoring using an implantable loop recorder

Funding Acknowledgements

Type of funding sources: None.

Background

A very late recurrence (VLR) of atrial fibrillation (AF) is considered present when patients have their first recurrence of AF > 12 months post-ablation. Little is known about the yearly rates and patterns of VLR AF recurrence.

Objective

To assess the yearly incidence and pattern of VLR in pts with AF who underwent cryoballoon (CB) pulmonary vein isolation (PVI).

Methods

We prospectively enrolled consecutive patients with AF who underwent CB PVI and had an implantable loop recorder (ILR) inserted up to 3 months post-ablation. Patients were followed for recurrent AF (excluding a 3-month post-ablation blanking period).

Results

Our cohort included 222 patients (66 ± 9 years; 143 [64%] male; 120 [54%] paroxysmal AF; CHA2DS2-VASc 2.6 ± 1.6). At 1-year, 111 (50%) patients remained free of AF. Two-year follow-up was available in 95 of these patients; 62 (65%) remained in sinus. Three-year follow-up was available in 42 of these patients; 36 (86%) remained in sinus (Figure). Of the 39 patients who developed AF after initially being free of AF for at least 1-year post ablation, 24 (62%) patients had either a frequent or persistent pattern of AF.

Conclusions

Our data show that the greatest likelihood of failure following a CB PVI occurs in the first year of ablation. The rate of failure becomes lower year by year. These data suggest that long term outcome may be driven more by the initial ablation as opposed to progressive evolution of the patient’s substrate

Is there clinical utility to replacement of an implantable loop recorder in patients who have previously undergone cryoballoon pulmonary vein isolation?

Funding Acknowledgements

Type of funding sources: None.

Background

Implantable loop recorders (ILRs) are used for long-term ECG monitoring following catheter ablation in patients (pts) with atrial fibrillation (AF) to guide clinical management. However, little is known about what do when the ILR reaches end of service (EOS).

Purpose

To identify pts who underwent replacement of their ILR and determine the diagnostic yield and clinical utility of the replacement device.

Methods

We enrolled 222 consecutive pts with AF who underwent cryoballoon pulmonary vein isolation (CB PVI) and had an ILR. We identified pts who subsequently underwent ILR replacement. The diagnostic and clinical utility of the newly replaced ILR was determined.

Results

The cohort included 56 pts (64 + 9 years; 35 [63%] male; 27 [48%] PAF; CHA2DS2-VASc 2.3 ± 1.5) in whom the initial ILR reached EOS. They were followed for 3.7 ± 2.1 years. Recurrent AF was observed in 41 (73%) of these pts; this triggered an intervention in 17 (41%) pts (Figure). Of the other 15 (27%) pts without any documented AF, anticoagulation was withheld in 13 [87%] pts. Following ILR replacement, 33 (80%) of the 41 pts had more AF (n=11 [33%] required an intervention) and 5 additional pts had AF for the first time.

Conclusions

Our data show that after CB PVI, ILRs help guide decisions regarding rhythm management and oral anticoagulation. When the initial ILR was replaced by a second ILR, AF was detected (often for the first time) in some patients; the findings were used to guide clinical decision making in the entire cohort. Thus, at this time, it remains undefined when ECG monitoring of these pts can be stopped because it is no longer clinical meaningful.

Defining the optimal blanking period duration after cryoballoon pulmonary vein isolation in patients with atrial fibrillation who have never been treated with an antiarrhythmic drug

Background

Cryoballoon (CB) pulmonary vein isolation (PVI) is an approved method for ablation in patients with paroxysmal (PAF) or persistent (PeAF) atrial fibrillation (AF). Although the first 90 days post-ablation are considered within the blanking period (BP), the optimal duration of the BP remains undefined.

Purpose

To objectively define the BP duration in pts undergoing CB PVI by evaluating a cohort never treated with an antiarrhythmic drug (AAD).

Methods

We enrolled consecutive pts with either PAF or PeAF who underwent initial CB PVI; all pts had an implantable loop recorder (ILR) for long-term ECG monitoring. No pt received an AAD either before or after ablation. We determined the time to last AF episode within the first 90 days of ablation. We then correlated this to the likelihood a patient had recurrent AF between 91 and 365 days of ablation.

Results

There were 45 pts (67±8 years; 26 [58%] male; 40 [89%] PAF; CHA2DS2-VASc 2.6±1.3). We defined 4 distinct groups post ablation based on whether or not they had AF in the BP: (1) no AF days 0–90 (n=19 [42%]), (2) last AF days 0–30 (n=11 [24%]), (3) last AF days 31–60 (n=3 [7%]), and (4) last AF days 61–90 (n=12 [27%]). After the 90-day BP, 15 (33%) pts had AF recurrence. Pts with no AF and those with AF only within 30 days of ablation had similar long-term outcome; however, recurrent AF more than 32 days after ablation predicted long-term ablation failure (Figure).

Conclusion

The post CB PVI blanking period is just a month. AF recurrences beyond a month in patients not on an AAD are associated with AF recurrence in the majority of pts.

Funding Acknowledgement

Type of funding sources: None. Blanking Group by AF Recurrence

Defining the blanking period duration after cryoballoon pulmonary vein isolation in patients taking an antiarrhythmic drug

Funding Acknowledgements

Type of funding sources: None.

Background

Cryoballoon pulmonary vein isolation (CB) is an accepted method for ablation in patients with atrial fibrillation (AF). A three-month blanking period (BP) is commonly used in clinical trials and practice. However, the actual BP duration in patients (pts) on an antiarrhythmic drug (AAD) at time of ablation remains undefined.

Objective

To objectively define the BP duration in pts undergoing CB while taking an AAD.

Methods

We enrolled consecutive pts with AF who had CB PVI while on an AAD. All pts had an implantable loop recorder (ILR). We prospectively followed all pts and determined the time to last AF episode during the 90-day post-PVI BP. This was then correlated with likelihood of having an AF recurrence between 3-12 months post-PVI.

Results

The cohort included 92 pts (66 ± 10 years; 62 [67%] male; 33 [36%] PAF; CHA2DS2-VASc 2.6 ± 1.7). AADs used included dofetilide (42), dronedarone (14), amiodarone (25), sotalol and propafenone (3 each), and flecainide (5). The AAD was stopped at a median of 80 [36, 105] days post-PVI.  We defined 4 distinct groups: (1) no AF in 90-day BP (n = 45 [49%]); (2) last AF within 30 days of PVI (n = 17 [18%]); (3) last AF within 60 days of PVI (n = 13 [15%]); and (4) last AF within 90 days of PVI (n = 17 [18%]). Following the 90-day BP, 47 (51%) pts had a recurrence of AF. Once recurrent AF was observed > 30 days post-ablation, patients had high likelihood of having a long term AF recurrence (p = 0.037, Figure).

Conclusion

Our data suggest that the optimal BP duration in AF patients undergoing CB PVI while taking an AAD is 30 days. An AF recurrence after 30 days is associated with a very high likelihood of recurrent AF during longer-term follow-up. Abstract Figure.

Clinical characteristics, treatment intent, and outcome in a consecutive 10-year cohort of oral cancer patients aged 75 years and older

The prevalence of oral squamous cell carcinoma (OSCC) in the elderly is expected to increase by nearly a third in the next decade. Its management in older patients is potentially more challenging due to their pre-existing medical comorbidities, frailty, reduced life expectancy, and social issues. The aim of this retrospective review was to report on treatment given to patients aged 75 years and over, case mix, and survival. All patients aged 75 years and over who were diagnosed with OSCC in Merseyside between 1 January 2007 and 31 December 2016, and treated with either curative or palliative intent, were included. Their hospital notes were reviewed. Fisher's exact test and Kaplan-Meier analysis were used for data analysis. There were 236 patients (median (IQR) age 81 (78-86) years); 67% were treated curatively and 33% palliatively. Factors associated with palliation included older age, advanced tumour stage, cognitive impairment, and residence in a nursing or residential home. Of the 165 patients who were offered curative treatment, six (4%) declined due to personal or family reasons. Overall survival for palliative patients was 12% at one year and 7% at two years, whereas for patients treated curatively it was 74% at one year, 56% at two years, and 34% at five years. Patients over 85 years of age were less likely to have composite free flaps and postoperative radiotherapy. Perioperative mortality was 2.6%. Improvements in surgical techniques and perioperative management have enabled clinicians to offer treatment with curative intent to older frail patients, and with careful case selection outcomes can be very good.

Chest CT screening for COVID-19 in elective and emergency surgical patients: experience from a UK tertiary centre

AIM

To determine the incidence of possible COVID-19-related lung changes on preoperative screening computed tomography (CT) for COVID-19 and how their findings influenced decision-making. To also to determine whether the patients were managed as COVID-19 patients after their imaging findings, and the proportion who had SARS-CoV2 reverse transcriptionpolymerase chain reaction (RT-PCR) testing.

MATERIALS AND METHODS

A retrospective study was undertaken of consecutive patients having imaging prior to urgent elective surgery (n=156) or acute abdominal imaging (n=283). Lung findings were categorised according to the British Society of Thoracic Imaging (BSTI) guidelines. RT-PCR testing, management, and outcomes were determined from the electronic patient records.

RESULTS

3% (13/439) of CT examinations demonstrated findings of classic/probable COVID-19 pneumonia, whilst 4% (19/439) had findings indeterminate for COVID-19. Of the total cohort, 1.6% (7/439) subsequently had confirmed RT-PCR-positive COVID-19. Importantly, all the patients with a normal chest or alternative diagnoses on CT who had PCR testing within the next 7 days, had a negative RT-PCR (92/407). There was a change in surgical outcome in 6% (10/156) of the elective surgical cohort with no change to surgical management was demonstrated in the acute abdominal emergency cohort requiring surgery (2/283).

CONCLUSION

There was a 7% (32/439) incidence of potential COVID-19-related lung changes in patients having preoperative CT. Although this altered surgical management in the elective surgical cohort, no change to surgical management was demonstrated in the acute abdominal emergency cohort requiring surgery.

An off-Campus College Program to Prepare Rehabilitation Teachers of Visually Impaired Students

An experimental off-campus training program for rehabilitation teachers of the visually impaired was cosponsored by Dominican College and the New York State Commission for the Blind and Visually Handicapped. The goal was to provide personnel in rural areas of the state where the need was the greatest. A unique feature of the program was the use of on-site rehabilitation teachers as adjunct faculty. Over a three-year period, 25 certifiable rehabilitation teachers were trained at four sites.

Quantifying citrate-enhanced phosphate root uptake using microdialysis

AIMS

Organic acid exudation by plant roots is thought to promote phosphate (P) solubilisation and bioavailability in soils with poorly available nutrients. Here we describe a new combined experimental (microdialysis) and modelling approach to quantify citrate-enhanced P desorption and its importance for root P uptake.

METHODS

To mimic the rhizosphere, microdialysis probes were placed in soil and perfused with citrate solutions (0.1, 1.0 and 10 mM) and the amount of P recovered from soil used to quantify rhizosphere P availability. Parameters in a mathematical model describing probe P uptake, citrate exudation, P movement and citrate-enhanced desorption were fit to the experimental data. These parameters were used in a model of a root which exuded citrate and absorbed P. The importance of soil citrate-P mobilisation for root P uptake was then quantified using this model.

RESULTS

A plant needs to exude citrate at a rate of 0.73 μmol cm^-1 of root h^-1 to see a significant increase in P absorption. Microdialysis probes with citrate in the perfusate were shown to absorb similar quantities of P to an exuding root.

CONCLUSION

A single root exuding citrate at a typical rate (4.3 × 10^-5 μmol m^-1 of root h^-1) did not contribute significantly to P uptake. Microdialysis probes show promise for measuring rhizosphere processes when calibration experiments and mathematical modelling are used to decouple microdialysis and rhizosphere mechanisms.

P1913Implantable Loop Recorder Detected Pattern of Atrial Fibrillation Recurrence Following Cryoballoon Pulmonary Vein Isolation in Patients with Persistent Atrial Fibrillation

Background

Cryoballoon (CB) pulmonary vein isolation (PVI) is increasingly being used in patients (pts) with persistent atrial fibrillation (AF). However, there are limited data about the pattern of atrial fibrillation (AF) recurrence in these pts.

Objective

To assess, using an implantable loop recorder (ILR), the patterns of AF recurrence following CB PVI in pts with persistent atrial fibrillation.

Methods

We enrolled consecutive pts with persistent AF ablation undergoing their first CB ablation. Other cavotricuspid isthmus ablation when indicated, no other ablation was performed. A Reveal LINQ ILR (Medtronic) was implanted <3 months following ablation; all pts had a minimum of 1-year follow-up. The recurrence of any atrial arrhythmia was determined and adjudicated; 4 distinct AF patterns were characterized (Figure).

Results

We studied 64 pts (66±9 years; 50 [78%] male; CHA2DS2-VASc 2.6±1.9) with persistent AF; 52 (81%) pts were on an antiarrhythmic drug (AAD) peri-ablation. During 803±361 days of follow-up, 33 (52%) pts had their 1st AF recurrence 91–365 days post-ablation and another 17 (27%) pts had their 1st AF recurrence >365 days post-ablation. No AF was seen in 14 (31%) pts. Most pts (33 of 50, 66%) with AF recurrence presented with 1 of 3 distinct patterns of paroxysmal AF (Figure), which ranged from 22 min to 124 hours. In 2/3 of these pts, all AF recurrences lasted <24 hours. Only 17 (34%) pts recurred with persistent AF.

Conclusion

Following single CB PVI, most pts with persistent AF remained free of persistent AF during long-term follow-up. Most pts with recurrent AF have 1 of 3 distinct patterns with episodes commonly last <24 hours. These data suggest that CB PVI ablation may halt AF progression in pts initially presenting with persistent AF.

Application of Bayesian statistics to estimate nitrous oxide emission factors of three nitrogen fertilisers on UK grasslands

Trapezoidal integration by linear interpolation of data points is by far the most commonly used method of cumulative flux calculations of nitrous oxide (N₂O) in studies that use flux chambers; however, this method is incapable of providing accurate uncertainty estimates. A Bayesian approach was used to calculate N₂O emission factors (EFs) and their associated uncertainties from flux chamber measurements made after the application of nitrogen fertilisers, in the form of ammonium nitrate (AN), urea (Ur) and urea treated with Agrotain® urease inhibitor (UI) at four grassland sites in the UK. The comparison between the cumulative fluxes estimated using the Bayesian and linear interpolation methods were broadly similar (R² = 0.79); however, the Bayesian method was capable of providing realistic uncertainties when a limited number of data points is available. The study reports mean EF values (and 95% confidence intervals) of 0.60 ± 0.63, 0.29 ± 0.22 and 0.26 ± 0.17% of applied N emitted as N₂O for the AN, Ur and UI treatments, respectively. There was no significant difference between N₂O emissions from the Ur and UI treatments. In the case of the automatic chamber data collected at one site in this study, the data did not fit the log-normal model, implying that more complex models may be needed, particularly for measurement data with high temporal resolution.

Health-related quality of life in patients with T1N0 oral squamous cell carcinoma: selective neck dissection compared with wait and watch surveillance

Management of the neck in patients with clinical T1N0 oral squamous cell carcinoma (SCC) is controversial. The aim of this study was to report the health-related quality of life (HRQoL) in a consecutive group of patients with stage 1 disease at a time closest to two years after primary surgery. Of 216 patients treated between 2007 and 2012 (after excluding early death and regional recurrence), 195 were eligible. HRQoL was measured using the University of Washington quality of life questionnaire version 4. The overall response rate was 65% (126/195). HRQoL outcomes were good, but compared with patients in the wait and watch group, those who had selective neck dissection (SND) had more problems regarding appearance (14% compared with 1%, p=0.008) and pain (19% compared with 6%, p=0.04). Similar trends were seen for shoulder (14% compared with 8%), mood (16% compared with 8%), and speech (5% compared with 1%), and for poorer overall QoL (30% compared with 16%). It is difficult to establish why patients did or did not have neck dissection in a retrospective sample, but it is likely that those who had SND had larger tumours. The findings highlight the impact that SND has on HRQoL in domains such as appearance, pain, speech, swallowing, and chewing. Previous studies on SND have tended to focus on injury to the accessory nerve and shoulder function, but these new data emphasise the need to include other domains in future trials that compare wait and watch, SND, and sentinel lymph node biopsy.

Ageing in corrective services: from the perspective of prison chaplains

The number of older inmates in New South Wales prisons has increased over the past ten years but it is unclear whether corrective services can cater for the increase. The current study reports the results of a qualitative study about ageing in prison. Eight prison chaplains from four corrective facilities in NSW were interviewed using a semi-structured interview schedule. The results of a thematic analysis revealed four main themes: the system, the services, the environment and the inmate. The themes reveal a system that is not designed to cope with an ageing population. Inmates become resentful of what has happened to them rather than for the damage they have done to somebody else. The system lacks processes and programmes to enable proper rehabilitation. The issues raised by the chaplains in terms of services, the environment and the inmates decrease the possibility that an older inmate will adapt to the environment and successfully age in place.

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.

The cost of oropharyngeal cancer in England: A retrospective hospital data analysis

OBJECTIVES

To estimate the total costs of treating head and neck cancers, specifically oropharyngeal, laryngeal and oral cavity cancer, in secondary care facilities in England during the period 2006/2007 to 2010/2011.

DESIGN

Patient records were extracted from an English hospital database to estimate the number of patients treated for oropharyngeal, laryngeal and oral cavity cancer in England. Identified resource use was linked to published United Kingdom cost estimates to quantify the reimbursement of treatment through the Payment by Results system.

SETTING

Retrospective hospital data analysis.

PARTICIPANTS

From the hospital data, patient records of patients treated for oropharyngeal, laryngeal and oral cavity cancer were selected.

MAIN OUTCOME MEASURES

Annual total costs of treatment, stratified by inpatient and outpatient setting and by male and female patients.

RESULTS

From 2006/2007 to 2010/2011, total costs of treatment across the three head and neck cancer sites were estimated to be approximately £309 million, with 90% attributable to inpatient care (bundled costs). Oropharyngeal cancer accounted for 37% of total costs. Costs and patient numbers increased over time, largely due to a rise in oropharyngeal cancer, where total costs increased from £17.21 million to £30.32 million, with over 1400 (52%) more inpatients treated in 2010/11 compared to 2006/07.

CONCLUSIONS

In 4 years, the number of patients with oropharyngeal cancer receiving some form of inpatient care increased by more than half, and associated costs increased by three quarters. This reinforces the case for prevention and early detection strategies to help contain this epidemiological and economic burden.

Current Concepts in Osteoradionecrosis after Head and Neck Radiotherapy

Osteoradionecrosis (ORN) of the jaws is a feared complication of head and neck radiotherapy. ORN causes significant morbidity for patients and controversy among clinicians. This overview considers the variations in definition and classification of the condition that affect estimates of incidence and also the interpretation of evidence. The influence of newer radiotherapy techniques in reducing ORN through reduced dose and xerostomia is balanced against a probable increase in a vulnerable population through a rising head and neck cancer incidence. Theories of pathophysiology of ORN include radiation-induced osteomyelitis, hypoxic and hypovascular theory and fibroatrophic theory. Prevention strategies include restorative dentistry and radiation planning techniques. Treatments range from conservative 'watch and wait' through to more radical surgical strategies. Newer medical management strategies are available with a limited evidence base. The use of hyperbaric oxygen therapy remains controversial and the background and need for newer hyperbaric oxygen trials is discussed.

Stacking faults in cronstedtite and other kaolin-type silicates

Die Struktur des Cronstedtits besteht aus regelmäßig gestapelten Silikatschichten. Stapelfehler treten nach Zufall auf; sie sind an strichformigen Röntgeninterferenzen erkennbar. An sechs Cronstedtit-Kristallen wurde die Ausdehnung der Striche gemessen und mit Hilfe der Wilsonschen Theorie der Beugung an fehlgeordneten Schichtstrukturen gedeutet. Die Wahrscheinlichkeit α der Fehlordnung wurde zwischen 0,08 und 0,30 gefunden.

Es wird ein neues, auf Zerlegung der Verschiebungen beruhendes Fehlordnungsmodell vorgeschlagen