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.

Impact of the COVID-19 Pandemic on Outcomes for Patients with Lung Cancer Receiving Curative-intent Radiotherapy in the UK

AIMS

Previous work found that during the first wave of the COVID-19 pandemic, 34% of patients with lung cancer treated with curative-intent radiotherapy in the UK had a change to their centre's usual standard of care treatment (Banfill et al. Clin Oncol 2022;34:19-27). We present the impact of these changes on patient outcomes.

MATERIALS AND METHODS

The COVID-RT Lung database was a prospective multicentre UK cohort study including patients with stage I-III lung cancer referred for and/or treated with radical radiotherapy between April and October 2020. Data were collected on patient demographics, radiotherapy and systemic treatments, toxicity, relapse and death. Multivariable Cox and logistic regression were used to assess the impact of having a change to radiotherapy on survival, distant relapse and grade ≥3 acute toxicity. The impact of omitting chemotherapy on survival and relapse was assessed using multivariable Cox regression.

RESULTS

Patient and follow-up forms were available for 1280 patients. Seven hundred and sixty-five (59.8%) patients were aged over 70 years and 603 (47.1%) were female. The median follow-up was 213 days (119, 376). Patients with stage I-II non-small cell lung cancer (NSCLC) who had a change to their radiotherapy had no significant increase in distant relapse (P = 0.859) or death (P = 0.884); however, they did have increased odds of grade ≥3 acute toxicity (P = 0.0348). Patients with stage III NSCLC who had a change to their radiotherapy had no significant increase in distant relapse (P = 0.216) or death (P = 0.789); however, they did have increased odds of grade ≥3 acute toxicity (P < 0.001). Patients with stage III NSCLC who had their chemotherapy omitted had no significant increase in distant relapse (P = 0.0827) or death (P = 0.0661).

CONCLUSION

This study suggests that changes to radiotherapy and chemotherapy made in response to the COVID-19 pandemic did not significantly affect distant relapse or survival. Changes to radiotherapy, namely increased hypofractionation, led to increased odds of grade ≥3 acute toxicity. These results are important, as hypofractionated treatments can help to reduce hospital attendances in the context of potential future emergency situations.

Assessment of the Implementation of Lung Cancer Consensus Statements From the Royal College of Radiologists in 2021; Progress and Barriers

BACKGROUND

Lung cancer outcomes in the UK are worse than those in many similar countries. The RCR developed a series of 43 consensus statements (CS) to facilitate improvements in care for patients treated with radiotherapy.

METHODS

We asked all 61 UK radiotherapy centres to self-assess the implementation of the CS and to describe their departmental key strengths and weaknesses in September 2021.

RESULTS

87% of centres returned their assessments. Whilst developmental activity was seen in most areas for most centres, 24 of the statements were felt to be difficult to implement within the next 2 years by at least one centre. The most frequently reported strengths were in the implementation of SABR (stereotactic body radiotherapy), concurrent chemoradiation for non-small cell lung cancer and technological aspects of treatment planning. The most frequently described departmental weaknesses were in pre-habilitation, timeliness of PET/CT scans and prophylaxis for Pneumocystis jiroveci Pneumonia (PJP). Barriers to implementation were often due to insufficient resource, a requirement for organisations to work together, and a perceived lack of evidence base. Strengths were often attributed to good team working, a local champion and being an early adopter.

CONCLUSIONS

This work confirms the commitment of lung cancer radiotherapy teams across the UK to improve outcomes for their patients. Most of the statements have been implemented at least partially. Themes have been identified to aid further progress, one of which is a requirement for significant investment.

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.

Changes in the Management of Patients having Radical Radiotherapy for Lung Cancer during the First Wave of the COVID-19 Pandemic in the UK

AIMS

In response to the COVID-19 pandemic, guidelines on reduced fractionation for patients treated with curative-intent radiotherapy were published, aimed at reducing the number of hospital attendances and potential exposure of vulnerable patients to minimise the risk of COVID-19 infection. We describe the changes that took place in the management of patients with stage I-III lung cancer from April to October 2020.

MATERIALS AND METHODS

Lung Radiotherapy during the COVID-19 Pandemic (COVID-RT Lung) is a prospective multicentre UK cohort study. The inclusion criteria were: patients with stage I-III lung cancer referred for and/or treated with radical radiotherapy between 2nd April and 2nd October 2020. Patients who had had a change in their management and those who continued with standard management were included. Data on demographics, COVID-19 diagnosis, diagnostic work-up, radiotherapy and systemic treatment were collected and reported as counts and percentages. Patient characteristics associated with a change in treatment were analysed using multivariable binary logistic regression.

RESULTS

In total, 1553 patients were included (median age 72 years, 49% female); 93 (12%) had a change to their diagnostic investigation and 528 (34%) had a change to their treatment from their centre's standard of care as a result of the COVID-19 pandemic. Age ≥70 years, male gender and stage III disease were associated with a change in treatment on multivariable analysis. Patients who had their treatment changed had a median of 15 fractions of radiotherapy compared with a median of 20 fractions in those who did not have their treatment changed. Low rates of COVID-19 infection were seen during or after radiotherapy, with only 21 patients (1.4%) developing the disease.

CONCLUSIONS

The COVID-19 pandemic resulted in changes to patient treatment in line with national recommendations. The main change was an increase in hypofractionation. Further work is ongoing to analyse the impact of these changes on patient outcomes.

The Influence of Different Physical Activity Behaviours on the Gut Microbiota of Older Irish Adults

OBJECTIVE

A 24-hour day is made up of time spent in a range of physical activity (PA) behaviours, including sleep, sedentary time, standing, light-intensity PA (LIPA) and moderate-to-vigorous PA (MVPA), all of which may have the potential to alter an individual's health through various different pathways and mechanisms. This study aimed to explore the relationship between PA behaviours and the gut microbiome in older adults.

DESIGN

Cross-sectional study.

SETTINGS AND PARTICIPANTS

Participants (n=100; age 69.0 [3.0] years; 44% female) from the Mitchelstown Cohort Rescreen (MCR) Study (2015-2017).

METHODS

Participants provided measures of gut microbiome composition (profiled by sequencing 16S rRNA gene amplicons), and objective measures of PA behaviours (by a 7-day wear protocol using an activPAL3 Micro).

RESULTS

Standing time was positively correlated with the abundance of butyrate-producing and anti-inflammatory bacteria, including Ruminococcaceae, Lachnospiraceae and Bifidobacterium, MVPA was positively associated with the abundance of Lachnospiraceae bacteria, while sedentary time was associated with lower abundance of Ruminococcaceae and higher abundance of Streptococcus spp.

CONCLUSION

Physical activity behaviours appear to influence gut microbiota composition in older adults, with different PA behaviours having diverging effects on gut microbiota composition.

Reduced Fractionation in Lung Cancer Patients Treated with Curative-intent Radiotherapy during the COVID-19 Pandemic

Patients treated with curative-intent lung radiotherapy are in the group at highest risk of severe complications and death from COVID-19. There is therefore an urgent need to reduce the risks associated with multiple hospital visits and their anti-cancer treatment. One recommendation is to consider alternative dose-fractionation schedules or radiotherapy techniques. This would also increase radiotherapy service capacity for operable patients with stage I-III lung cancer, who might be unable to have surgery during the pandemic. Here we identify reduced-fractionation for curative-intent radiotherapy regimes in lung cancer, from a literature search carried out between 20/03/2020 and 30/03/2020 as well as published and unpublished audits of hypofractionated regimes from UK centres. Evidence, practical considerations and limitations are discussed for early-stage NSCLC, stage III NSCLC, early-stage and locally advanced SCLC. We recommend discussion of this guidance document with other specialist lung MDT members to disseminate the potential changes to radiotherapy practices that could be made to reduce pressure on other departments such as thoracic surgery. It is also a crucial part of the consent process to ensure that the risks and benefits of undergoing cancer treatment during the COVID-19 pandemic and the uncertainties surrounding toxicity from reduced fractionation have been adequately discussed with patients. Furthermore, centres should document all deviations from standard protocols, and we urge all colleagues, where possible, to join national/international data collection initiatives (such as COVID-RT Lung) aimed at recording the impact of the COVID-19 pandemic on lung cancer treatment and outcomes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Mental health and well-being in parents of excessively crying infants: Prospective evaluation of a support package

BACKGROUND

During the first 4 months of age, approximately 20% of infants cry a lot without an apparent reason. Most research has targeted the crying, but the impact of the crying on parents, and subsequent outcomes, need to receive equal attention. This study reports the findings from a prospective evaluation of a package of materials designed to support the well-being and mental health of parents who judge their infant to be crying excessively. The resulting "Surviving Crying" package comprised a website, printed materials, and programme of Cognitive Behaviour Therapy-based support sessions delivered to parents by a qualified practitioner. It was designed to be suitable for United Kingdom (UK) National Health Service (NHS) use.

METHODS

Parents were referred to the study by 12 NHS Health Visitor/Community Public Health Nurse teams in one UK East Midlands NHS Trust. Fifty-two of 57 parents of excessively crying babies received the support package and completed the Edinburgh Postnatal Depression Scale and Generalized Anxiety Disorder-7 anxiety questionnaire, as well as other measures, before receiving the support package and afterwards.

RESULTS

Significant reductions in depression and anxiety were found, with numbers of parents meeting clinical criteria for depression or anxiety halving between baseline and outcome. These improvements were not explained by reductions in infant crying. Reductions also occurred in the number of parents reporting the crying to be a large or severe problem (from 28 to 3 parents) or feeling very or extremely frustrated by the crying (from 31 to 1 parent). Other findings included increases in parents' confidence, knowledge of infant crying, and improvements in parents' sleep.

CONCLUSIONS

The findings suggest that the Surviving Crying package may be effective in supporting the well-being and mental health of parents of excessively crying babies. Further, large-scale controlled trials of the package in NHS settings are warranted.

The cross-sectional associations between objectively measured sedentary time and cardiometabolic health markers in adults - a systematic review with meta-analysis component

Sedentary time is viewed as an independent risk factor for adverse cardiometabolic health (CMH). No systematic review and meta-analysis on the cross-sectional associations between objectively measured sedentary time and CMH markers has been conducted. PubMed, Scopus and Web of Science Core Collection were searched for papers that examined the cross-sectional association between objectively measured sedentary time and CMH markers in adults. Forty-six papers met the inclusion criteria. The included papers had a combined sample size of 70,576 and an age range of 18-87 years. To examine the effect of increased levels of sedentary time on CMH markers, data on effect sizes and moderators were extracted, where possible. By pooling the unadjusted data from the included papers, increased sedentary time was shown to have a significant detrimental association with fasting glucose (Δ = 0.12, 95% confidence interval [CI]: 0.02, 0.23), fasting insulin (Δ = 0.19, 95% CI: 0.06, 0.32), triglycerides (Δ = 0.25, 95% CI: 0.14, 0.37), high-density lipoprotein cholesterol (Δ = -0.20, 95% CI: -0.28, -0.13) and waist circumference (Δ = 0.25, 95% CI: 0.15, 0.35). How sedentary time was quantified and the device used to measure sedentary time significantly influence the size of the effect reported. Future interventions focused on both decreasing sedentary time and increasing physical activity may be the most effective strategy to improve CMH.

Role of nutritional status and intervention in oesophageal cancer treated with definitive chemoradiotherapy: outcomes from SCOPE1

BACKGROUND

Malnutrition is common in oesophageal cancer. We aimed to identify nutritional prognostic factors and survival outcomes associated with nutritional intervention in the SCOPE1 (Study of Chemoradiotherapy in OesoPhageal Cancer with or without Erbitux) trial.

METHODS

Two hundred and fifty eight patients were randomly allocated to definitive chemoradiotherapy (dCRT) +/- cetuximab. Nutritional Risk Index (NRI) scores were calculated; NRI<100 identified patients at risk of malnutrition. Nutritional intervention included dietary advice, oral supplementation or major intervention (enteral feeding/tube placement). Univariable and multivariable analyses using Cox proportional hazard modelling were conducted.

RESULTS

At baseline NRI<100 strongly predicted for reduced overall survival (hazard ratio (HR) 12.45, 95% CI 5.24-29.57; P<0.001). Nutritional intervention improved survival if provided at baseline (dietary advice (HR 0.12, P=0.004), oral supplementation (HR 0.13, P<0.001) or major intervention (HR 0.13, P=0.003)), but not if provided later in the treatment course. Cetuximab patients receiving major nutritional intervention had worse outcomes compared with controls (13 vs 28 months, P=0.003).

CONCLUSIONS

Pre-treatment assessment and correction of malnutrition may improve survival outcomes in oesophageal cancer patients treated with dCRT. Nutritional Risk Index is a simple and objective screening tool to identify patients at risk of malnutrition.

Are we seeing the effects of public awareness campaigns? A 10-year analysis of Breslow thickness at presentation of malignant melanoma in the South West of England

INTRODUCTION

The last 20 years has seen a marked improvement in skin cancer awareness campaigns. We sought to establish whether this has affected the presenting Breslow thickness of malignant melanoma in the South West.

METHOD

This is a retrospective study looking at the first presentation of melanomas from 2003 to 2011. Data was accessed using the local online melanoma database.

RESULTS

A total of 2001 new melanomas presented from 2003 to 2012 (Male:Female = 1:1.062). The average yearly number of melanomas was 200.1 (range = 138-312). The mean age was 62.5 years (range 12-99). Data was analysed using a Chi² test. For 0-1 mm melanomas, there is a significant difference in the observed versus expected values over the 10 years (p = 0.0018). There is an increasing proportion of 0-1 mm (thin) melanomas presenting year on year, with a positive linear trend. This is very statistically significant (p < 0.0001). The 1-2 mm melanomas are decreasing in proportion with a negative linear trend (p = 0.0013). The 2-4 mm are also decreasing in proportion (p = 0.0253). There is no significant change in the thick >4 mm melanomas (p = 0.1456).

CONCLUSION

The proportion of thin 0-1 mm melanomas presenting in South West England has significantly increased from 2003 to 2012. There is no significant change in the thick >4 mm melanomas. This may be a result of increased public awareness due to effective public health campaigns which has significant prognostic and financial implications.

First Report of Zebra Chip and 'Candidatus Liberibacter solanacearum' on Potatoes in Nicaragua

In September 2011, potato (Solanum tuberosum) tubers grown in Nicaragua outside of Estelí and Jinotega were observed with internal discoloration suggestive of zebra chip (ZC); and the plants showed foliar symptoms of chlorosis, leaf scorching, wilting, vascular discoloration, swollen nodes, twisted stems, and aerial tubers (3). Disease incidence ranged from 50 to 95% in eight fields ranging from 5 to 12 ha in the Estelí and Jinotega regions of Nicaragua. Leaf samples and psyllids were collected from two fields, and total DNA was purified from the leaves of 17 symptomatic and 10 asymptomatic plants. DNA was also extracted from 20 individual potato psyllids. Primers specific for 16S rDNA (OA2 and OI2c) and the surface antigen gene (OMB 1482f and 2086r) of Candidatus Liberibacter solanacearum (CLs) were used to confirm the presence of the pathogen in infected potatoes and insects (2). All symptomatic potato leaf samples tested positive for the presence of CLs using both primers, and no asymptomatic plants had positive results. Seven insects tested positive for the presence of CLs. 16S rDNA sequences obtained for all positive samples (1,071 bp) were identical and showed 99 to 100% identity to a number of rDNA sequences of CLs in GenBank (Accession Nos. HM246509 and FJ957897). 16S rDNA sequences from two CLs-infected plants, one from Estelí, Nicaragua (JX559779) and one from Jinotega, Nicaragua (JK559780), were deposited in GenBank. Identity of insects was done using a morphological key, and then verified as Bactericera cockerelli using a real-time PCR assay with melt temperature analysis of the cytochrome c oxidase 1 gene, as described by Chapman et al. (1). Sequencing of the amplified DNA yielded an approximately 63-bp read, with 100% homology to reference sequences of B. cockerelli (AY971886) and those obtained from psyllids collected in McAllen, TX, in 2010. B. cockerelli samples were collected from both locations. Similar to previous reports of ZC in new locations, foliar and tuber symptoms associated with ZC were observed in all eight fields in these two Nicaraguan potato-growing regions, specific PCR amplification with two primer pairs was completed, 16S rDNA sequence analyses showed 100% similarity to reference sequences of CLs, and the presence of potato psyllids which tested positive for the presence of CLs provide evidence that ZC is now present in Nicaragua. Potatoes rank in the top 20 commodities produced in Nicaragua, resulting in >$4.5M annual revenue. Because CLs has caused significant economic damage to potatoes in the United States, Mexico, Guatemala, and Honduras, this finding has significance for potato production in Central America. References: (1) R. I. Chapman et al. Southwest. Entomol. 37:475, 2012. (2) J. M. Crosslin. Southwest. Entomol. 36:125, 2011. (3) L. W. Liefting et al. Internat. J. Syst. Evol. Microbiol. 59:2274, 2009.

Prevalence of overweight and obesity among children six to ten years of age in the north-east health region of Jamaica

OBJECTIVE

To estimate the prevalence and correlates of overweight and obesity among children six to ten years old in the North-East Health Region (NEHR) ofJamaica.

METHODS

Weights and heights were measured in a representative sample of 5710 children between the ages of six and ten years in 34 schools between October 2008 and March 2009. Overweight and obesity were defined as body mass index (BMI) Z-score > 1SD and >2SD, respectively based on the World Health Organization (WHO)-endorsed age and gender-specific growth standards for children. Point prevalence estimates of overweight and obesity were calculated. Odds ratios (OR) and 95% confidence intervals (CI) were used to estimate associations between overweight and obesity and age, gender and school location.

RESULTS

Overweight and obesity prevalence among children six to ten years old in NEHR, Jamaica, was 10.6% and 7.1%, respectively. Overweight (OR = 1.11, 95% CI: 1.04, 1.18) and obesity (OR = 1.17, 95% CI: 1.08, 1.26) prevalence increased significantly with age. Overweight (OR = 1.51, 95% CI: 1.27, 1.80) and obesity (OR = 1.36, 95% CI: 1.11, 1.67) prevalence was significantly higher among girls than boys. Children attending rural-public schools had less risk of being overweight (OR = 0.57, 95% CI: 0.46, 0.70) and obese (OR = 0.35, 95% CI: 0.28, 0.44) when compared with urban-public schools and private schools. Both overweight (OR = 2.11, 95% CI: 1.60, 2.78) and obesity (OR = 1.68, 95% CI: 1.24, 2.28) were significantly more common among children attending private schools. After adjusting for age and gender the results still remained statistically significant.

CONCLUSIONS

Overweight/obesity prevalence among children six to ten years old in NEHR of Jamaica is 17.7% with older children and girls having higher rates. Children attending urban-public and private schools have higher prevalence than those attending rural schools. Appropriately targeted interventions are needed to combat this problem.

Technical note: 9-month repositioning accuracy for functional response assessment in head and neck chemoradiotherapy

The use of thermoplastic immobilisation masks in head and neck radiotherapy is now common practice. The accuracy of these systems has been widely studied, but always within the context and time frame of the radiation delivery-some 6-8 weeks. There is growing current interest in the use of functional imaging to assess the response to treatment, particularly in the head and neck. It is therefore of interest to determine the accuracy with which functional images can be registered to baseline CT over the extended periods of time used for functional response assessment: 3-6 months after radiotherapy. In this study, repeated contrast-enhanced diagnostic quality CT and mid-quality localisation CT from a positron emission tomography/CT scanner were available for five time points over a period of 9 months (before, during and up to 6 months after chemoradiotherapy) for a series of eight patients enrolled in a clinical pilot study. All images were acquired using thermoplastic immobilisation masks. The overall set-up accuracy obtained from this 9-month study of 5.5 ± 3.2 mm (1 standard deviation) and 1.9 ± 1.3° (1 standard deviation) is in agreement with published data acquired over 6-8 weeks. No statistically significant change in set-up error was seen with time. This work indicates that thermoplastic immobilisation masks can be used to accurately align multimodality functional image data for assessment of the response to treatment in head and neck patients over extended follow-up periods.

The presence of radiological features on chest radiographs: how well do clinicians agree?

AIM

To compare levels of agreement amongst paediatric clinicians with those amongst consultant paediatric radiologists when interpreting chest radiographs (CXRs).

MATERIALS AND METHODS

Four paediatric radiologists used picture archiving and communication system (PACS) workstations to evaluate the presence of five radiological features of infection, independently in each of 30 CXRs. The radiographs were obtained over 1 year (2008) from children with fever and signs of respiratory distress, aged 6 months to <16 years. The same CXRs were interpreted a second time by the paediatric radiologists and by 21 clinicians with varying experience levels, using the Web 1000 viewing system and a projector. Intra- and interobserver agreement within groups, split by grade and specialty, were analysed using free-marginal multi-rater kappa.

RESULTS

Normal CXRs were identified consistently amongst all 25 participants. The four paediatric radiologists showed high levels of intraobserver agreement between methods (kappa scores between 0.53 and 1.00) and interobserver agreement for each method (kappa scores between 0.67 and 0.96 for PACS assessment). The 21 clinicians showed varying levels of agreement from 0.21 to 0.89.

CONCLUSION

Paediatric radiologists showed high levels of agreement for all features. In general, the clinicians had lower levels of agreement than the radiologists. This study highlights the need for improved training in interpreting CXRs for clinicians and the timely reporting of CXRs by radiologists to allow appropriate patient management.

Fluoroscopy as a surrogate for lung tumour motion

OBJECTIVES

The aim of this article was to test a simple approach of using pixel density values from fluoroscopy images to enable gated radiotherapy.

METHODS

Anterior and lateral (LAT) from images were acquired from 18 patients referred for radical radiotherapy for non-small cell lung cancer for a period of 30-45 s. The amplitude of movement and the number of breathing cycles were determined in the right-left (RL) and superoinferior (SI) directions on the anterior images and the anteroposterior (AP) and SI directions on the lateral images. The breathing pattern was created by analysing the variation in a summation of pixel values within a defined area. The greatest and lowest 30% of pixel values were set as the duty cycle to represent inhale and exhale amplitude-based gating.

RESULTS

A median of eight breathing cycles was captured for each patient with a duration of 2.2-11.8 s per cycle. The mean (range) motion was 4.7 mm (2.4-5.8 mm), 7.2 mm (2.3-17.6 mm), 6.2 mm (1.9-13.8 mm) and 4.8 mm (2.4-11.3 mm) in the RL, SI (AP), SI (LAT) and AP directions, respectively. A total of 10/14 anterior videos and 7/11 LAT videos had correlations between motion and breathing of >0.6. Margins of 5.5 mm, 6.8 mm and 6.6 mm in the RL, SI and AP directions, respectively, were determined to gate in exhale. The benefit of gating was greater when motion was >5 mm.

CONCLUSION

The simple approach of using pixel density values from fluoroscopy images to distinguish inhale from exhale and enable gating was successfully applied in all patients. This technique may potentially provide an accurate surrogate for tumour position.

The ties that bind: perceived social support, stress, and IBS in severely affected patients

BACKGROUND

This study assessed the association between social support and the severity of irritable bowel syndrome (IBS) symptoms in a sample of severely affected IBS patients recruited to an NIH-funded clinical trial. In addition, we examined if the effects of social support on IBS pain are mediated through the effects on stress.

METHODS

Subjects were 105 Rome II diagnosed IBS patients (F = 85%) who completed seven questionnaires which were collected as part of a pretreatment baseline assessment.

KEY RESULTS

Partial correlations were conducted to clarify the relationships between social support and clinically relevant variables with baseline levels of psychopathology, holding constant number of comorbid medical diseases, age, gender, marital status, ethnicity, and education. Analyses indicated that social support was inversely related to IBS symptom severity. Social support was positively related with less severe pain. A similar pattern of data was found for perceived stress but not quality of life impairment. Regression analyses examined if the effects of social support on pain are mediated by stress. The effects of social support on bodily pain were mediated by stress such that the greater the social support the less stress and the less pain. This effect did not hold for symptom severity, quality of life, or psychological distress.

CONCLUSIONS & INFERENCES

This study links the perceived adequacy of social support to the global severity of symptoms of IBS and its cardinal symptom (pain). It also suggests that the mechanism by which social support alleviates pain is through a reduction in stress levels.