A joint physics and radiobiology DREAM team vision - Towards better response prediction models to advance radiotherapy

Radiotherapy developed empirically through experience balancing tumour control and normal tissue toxicities. Early simple mathematical models formalized this practical knowledge and enabled effective cancer treatment to date. Remarkable advances in technology, computing, and experimental biology now create opportunities to incorporate this knowledge into enhanced computational models. The ESTRO DREAM (Dose Response, Experiment, Analysis, Modelling) workshop brought together experts across disciplines to pursue the vision of personalized radiotherapy for optimal outcomes through advanced modelling. The ultimate vision is leveraging quantitative models dynamically during therapy to ultimately achieve truly adaptive and biologically guided radiotherapy at the population as well as individual patient-based levels. This requires the generation of models that inform response-based adaptations, individually optimized delivery and enable biological monitoring to provide decision support to clinicians. The goal is expanding to models that can drive the realization of personalized therapy for optimal outcomes. This position paper provides their propositions that describe how innovations in biology, physics, mathematics, and data science including AI could inform models and improve predictions. It consolidates the DREAM team's consensus on scientific priorities and organizational requirements. Scientifically, it stresses the need for rigorous, multifaceted model development, comprehensive validation and clinical applicability and significance. Organizationally, it reinforces the prerequisites of interdisciplinary research and collaboration between physicians, medical physicists, radiobiologists, and computational scientists throughout model development. Solely by a shared understanding of clinical needs, biological mechanisms, and computational methods, more informed models can be created. Future research environment and support must facilitate this integrative method of operation across multiple disciplines.

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.

Barriers and facilitators to consuming pulses: a qualitative exploration including effects of trying recipes at home

Pulses are a healthy, sustainable, low cost food, but consumption levels are low for a variety of reasons, including practical and cooking concerns. This work aimed to explore barriers and facilitators towards pulse consumption and increasing consumption, and the potential value of cooking suggestions and recipes for changing these perceptions. Two qualitative studies were undertaken. In Study 1, 21 participants (10 males, 11 females, of a range of ages, cooking responsibilities, and experiences with pulses) were interviewed both before and after receiving cooking suggestions and recipes. In Study 2, 12 participants (2 males, 10 females, as above) were interviewed once after trying recipes. Interviews were audio-recorded, transcribed, and analysed using thematic analysis. Seven themes described barriers and facilitators towards pulse consumption: 'Enjoyment and Sensory properties'; 'Benefits and Recommendations'; 'Practical Concerns'; 'Cooking Concerns'; 'Compatibility with current diet'; 'Personal Influences'; and 'External Influences'. Some similar themes also referred to increasing consumption: 'Willingness'; 'Awareness, Knowledge of Benefits'; 'Knowledge of Cooking and Practical Concerns'; and 'Compatibility with current diet'. Cooking suggestions and recipe use resulted in themes on 'Awareness'; 'Willingness, Trying New Things'; 'Small Changes'; and facilitators associated with 'Enjoyment, Sensory Properties, Practical Concerns, Benefits' and 'Knowledge, Cooking Ideas and Confidence, Incorporation, Cooking Solutions'. Barriers related to 'Risk and Preconceptions'; 'Awareness, but' inaction and additional considerations were also found. Our findings demonstrate a positive role for pulse consumption for increased experience, familiarity, and confidence with preparing, cooking, and consuming these healthy and sustainable foods.

Youth Empowered Advocating for Health (YEAH): Facilitating Partnerships Between Prevention Scientists and Black Youth to Promote Health Equity

Structural racism inflicts a disproportionate burden of stress and trauma within Black communities, resulting in physical and mental health inequities that impact Black youth. Yet few multilevel interventions exist to address these deeply rooted inequities from a preventive standpoint, and even fewer are informed by the participatory input of the impacted communities. To bridge these gaps, we developed a community-based prevention strategy that promotes agency and active resistance to structural racism, Youth Empowered Advocating for Health (YEAH), and implemented it across various settings. We outline the development, implementation, and expansion of YEAH as a tool for promoting optimal health among Black communities. Lastly, we discuss lessons learned and offer a framework outlining key principles for prevention scientists to partner with Black youth and engage them in translational science to address structural racism. This framework is aimed at driving policies, practices, and procedures that promote equitable and sustainable change for and with Black communities.

Response-Adapted Omission of Radiotherapy in Pediatric Patients with Intermediate- and High-Risk Hodgkin Lymphoma Treated per EuroNet-PHL-C1: A Single Institution Analysis of Outcomes and Patterns of Failure

PURPOSE/OBJECTIVE(S)

EuroNet-PHL-C1 demonstrated that 40% of intermediate- and high-risk pediatric Hodgkin lymphoma (HL) patients treated with OEPA-COPDAC chemotherapy achieved adequate response (AR) at early response assessment (ERA), and thus were able to omit radiotherapy (RT). However, patterns of failure with this treatment paradigm, and specifically, whether or not all initial sites of disease require RT for those with inadequate response (IR) at ERA is unknown. The purpose of our study is to examine outcomes and patterns of failure for those treated per EuroNet-PHL-C1 at our institution. Our hypothesis is that limiting RT to only sites of IR at ERA does not result in increased failures.

MATERIALS/METHODS

An IRB-approved retrospective review of all intermediate- and high-risk classical HL pediatric patients treated at our institution per EuroNet-PHL-C1 between 2015 and 2021 was performed. Patients were treated per protocol with radiation omitted for those with AR (Deauville 1-2 and >75% tumor shrinkage) at ERA (PET/CDT after 2 cycles of chemo). For those with IR who required RT, only sites of IR (Deauville 3-5) at ERA were treated using involved site radiation treatment (ISRT), instead of all initial sites of disease as on EuroNet-PHL-C1. Outcomes including overall survival (OS) and progression free survival (PFS) were calculated using Kaplan-Meier curves and patterns of failure were classified as either initial site only, new site only, or initial and new sites.

RESULTS

A total of 35 patients were identified, of which 33 had evaluable follow up with median follow up of 33 months. The median age at diagnosis was 14 (range, 4-18) and 48% were female. Of the 33, 7 (21%) had IR at ERA and thus required RT, while 26 (79%) were spared RT. In the group who received RT, 4/7 (57%) had initial B-symptoms and 4/7 (57%) had initial bulky disease, compared to 9/26 (35%) and 20/26 (77%), respectively, in those who did not receive RT. For our entire cohort, 2-year PFS and OS were 91% and 100%, respectively. For those who had RT, 2-year PFS was 83% compared to 92% in those who did not need RT. There was a total of 3 relapses (9%) at last follow up with 1/7 (14%) in those who had RT vs. 2/26 (8%) in those without RT. For the patient who relapsed after RT, relapse occurred both at initial and new sites. For the 2 who relapsed who did not receive RT, 1 was both in initial and new sites, while the other was initial site only.

CONCLUSION

At our institution, the majority of patients treated per EuroNet-PHL-C1 avoided RT with excellent outcomes. For those requiring RT, limiting RT to only sites of IR at ERA does not appear to adversely affect outcomes, though analysis is limited by the low number of failures.

Extra-mandibular Osteoradionecrosis after the Treatment of Head and Neck Cancer

AIMS

Osteoradionecrosis (ORN) is a serious toxicity of head and neck radiotherapy. It predominantly affects the mandible. Extra-mandibular ORN is rare. The aim of this study was to report the incidence and outcomes of extra-mandibular ORNs from a large institutional database.

MATERIALS AND METHODS

In total, 2303 head and neck cancer patients were treated with radical or adjuvant radiotherapy. Of these, extra-mandibular ORN developed in 13 patients (0.5%).

RESULTS

Maxillary ORNs (n = 8) were a consequence of the treatment of various primaries (oropharynx = 3, sinonasal = 2, maxilla = 2, parotid = 1). The median interval from the end of radiotherapy to the development of ORN was 7.5 months (range 3-42 months). The median radiotherapy dose in the centre of the ORN was 48.5 Gy (range 22-66.5 Gy). Four patients (50%) healed in 7, 14, 20 and 41 months. All temporal bone ORNs (n = 5) developed after treatment to the parotid gland (of a total of 115 patients who received radiotherapy for parotid gland malignancy). The median interval from the end of radiotherapy to the development of ORN was 41 months (range 20-68 months). The median total dose in the centre of the ORN was 63.5 Gy (range 60.2-65.3 Gy). ORN healed in only one patient after 32 months of treatment with repeated debridement and topical betamethasone cream.

CONCLUSION

Extra-mandibular ORN is a rare late toxicity and this current study provides useful information on its incidence and outcome. The risk of temporal bone ORN should be considered in the treatment of parotid malignancies and patients should be counselled. More research is required to determine the optimal management of extra-mandibular ORN, particularly on the role of the PENTOCLO regimen.

Role of Adjuvant Radiotherapy in Acinic Cell Carcinoma of the Salivary Glands: A Systematic Review

A systematic review was carried out to evaluate if adjuvant radiotherapy for acinic cell carcinomas (ACCs) of salivary glands improves survival. Twelve retrospective studies published between 2000 and 2020 that analysed the effect of radiotherapy on salivary gland neoplasms and ACCs of salivary glands and met the inclusion criteria were included in the review. The overall quality of the studies was moderate to low. There was no high-quality evidence for improved survival with radiotherapy for ACCs of the salivary gland. Some evidence suggests that there may be an advantage for patients with high-grade tumours, but these data should be interpreted with caution due to the small number of patients and low-quality evidence. Good quality of evidence is lacking. Recommendation for adjuvant radiotherapy for tumours with poor prognostic factors will require discussion and shared decision-making with the patients.

What do we want? Training! When do we want it? Now? A training needs analysis for adaptive radiotherapy for therapeutic radiographers

INTRODUCTION

Therapeutic radiographers (TRs) have adapted to the changing requirements and demands of the oncology service and in response to advanced techniques such as on-line adaptive MRI-guided radiotherapy (MRIgRT). The skills required for MRIgRT would benefit many TRs not just those involved in this technique. This study presents the results of a training needs analysis (TNA) for the required MRIgRT skills in readiness for training TRs for current and future practice.

METHODS

A UK-based TNA was used to ask TRs about their knowledge and experience with essential skills required for MRIgRT based on previous investigations into the topic. A five-point Likert scale was used for each of the skills and the difference in values were used to calculate the training need for current and future practice.

RESULTS

261 responses were received (n = 261). The skill rated the most important to current practice was CBCT/CT matching and/or fusion. The current highest priority needs were radiotherapy planning and radiotherapy dosimetry. The skill rated the most important to future practice was CBCT/CT matching and/or fusion. The future highest priority needs were MRI acquisition and MRI Contouring. Over 50% of participants wanted training or additional training in all skills. There was an increase in all values for skills investigated from current to future roles.

CONCLUSION

Although the examined skills were viewed as important to current roles, the future training needs, both overall and high priority, were different compared to current roles. As the 'future' of radiotherapy can arrive rapidly, it is essential that training is delivered appropriately and timely. Before this can occur, there must be investigations into the method and delivery of this training.

IMPLICATIONS FOR PRACTICE

Role development. Education changes for therapeutic radiographers.

Tool for automatic macrozone characterization from EBSD data sets of titanium alloys

Microtexture heterogeneities are commonly found in titanium forgings because of the thermomechanical processing. Also known as macrozones, these regions can reach millimetres in length, with grains sharing a similar crystallographic orientation leading to less resistance to crack propagation. Since the link between macrozones and the reduction of cold-dwell-fatigue performance on rotative components in gas turbine engines was established, efforts have been put into macrozone definition and characterization. The electron backscatter diffraction (EBSD) technique, widely used for texture analysis, allows for a qualitative macrozone characterization; however, further processing is required to define the boundaries and disorientation spread of each macrozone. Current approaches often use c-axis misorientation criteria, but this can sometimes lead to a large disorientation spread within a macrozone. This article describes the development and application of a computational tool implemented in MATLAB for automatic macrozone identification from EBSD data sets on the basis of a more conservative approach where both the c-axis tilting and rotation are considered. The tool allows for detection of macrozones according to the disorientation angle and density-fraction criteria. The clustering efficiency is validated by pole-figure plots, and the effects of the key parameters defining the macrozone clustering (disorientation and fraction) are discussed. In addition, this tool was successfully applied to both fully equiaxed and bimodal microstructures of titanium forgings.

Images and images: Current roles of therapeutic radiographers

INTRODUCTION

Therapeutic radiography is a small profession and has adapted in response to advanced techniques. An increase in on-line adaptive MRI-guided radiotherapy (MRIgRT) will require role extension for therapeutic radiographers (TRs). This study will investigate the current role description for TRs and the activities they currently undertake with regards to MRIgRT.

METHOD

A training needs analysis was used to ask TRs about their current roles and responsibilities and essential skills required for MRIgRT. For the purposes of this paper, the authors present the results from the demographics of the individual, their current job title with roles and responsibilities, and experience with decision making and image assessment. Descriptive statistics was used to analyse the data.

RESULTS

261 responses were received (n = 261). Only 28% of job titles listed contained the protected title of 'therapeutic radiographer'. Advanced clinical practice roles were expressed by participants indicating that if a service need is presented, emerging roles will be created. Variation existed across the standardised roles of TRs and this discrepancy could present challenges when training for MRIgRT. TRs are pivotal in image verification and recognition on a standard linac, and skills developed there can be transferred to MRIgRT. Decision making is crucial for adaptive techniques and there are many skills within their current scope of practice that are indispensable for the MRIgRT.

CONCLUSION

It has been demonstrated that TRs have a range of roles that cover vast areas of the oncology pathway and so it is important that TRs are recognised so the pivotal role they play is understood by all. TRs have extensive soft-tissue IGRT knowledge and experience, aiding the evolution of decision-making skills and application of off-protocol judgments, the basis of MRIgRT.

IMPLICATIONS FOR PRACTICE

Role development and changes in education for therapeutic radiographers.

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.

Knowledge and attitudes toward repetitive transcranial magnetic stimulation (rTMS) as a treatment for postpartum and peripartum depression

Introduction

Postpartum and peripartum depression are debilitating disorders that impact the mother and their ability to care for their children’s emotional, social, and physical needs. Current treatments include psychotherapy, pharmacotherapy, and electroconvulsive therapy. These treatments are moderately effective or come with side effects that can negatively impact mother and child. As a result, many mothers view some treatments as unacceptable while pregnant or breastfeeding. Over the last decade, repetitive transcranial magnetic stimulation (rTMS) has shown promise as an effective and safe treatment option for postpartum and peripartum depression. However, little is known regarding people’s knowledge and attitudes towards this emerging technology, with no research assessing this in Canada.

Objectives

We aim to identify gaps in knowledge and to assess attitudes toward rTMS as a treatment for postpartum and peripartum depression in mental health professionals, patients, and the general public living in Canada.

Methods

A mixed methods study design will be employed. The qualitative portion will consist of individual semi-structured interviews. An inductive thematic analysis will be completed. The quantitative portion will consist of an anonymous, self-administered survey shared through REDCap. Focus groups with rTMS experts will be conducted to inform survey creation.

Results

No resulst at this time.

Conclusions

Understanding gaps in knowledge and attitudes toward rTMS is the first step toward ensuring that everyone is well informed and able to access safe and effective treatments. With limited treatment options available to a postpartum and/or peripartum depression patients being well informed on all treatments is crucial towards accessing treatments that best suit their needs.

Disclosure

No significant relationships.

Shock first, ask questions later…

A 39-year-old man presented to the Emergency Department following a sudden onset of palpitations an hour earlier. He was clammy and felt generally unwell. He was normally fit and active with no history of cardiac symptoms including palpitations - he mentioned as a teenager he was told that he had an 'extra bit of wiring in his heart' but nothing further was done. His only regular medication was Sertraline. He drank alcohol to excess. On examination, he was hypotensive but pain free. Bloods including potassium and magnesium were within normal limits - venous lactate was mildly elevated at 2.8.

Relapsing Klebsiella pneumoniae meningitis in a patient with COVID-19

Klebsiella pneumoniae is a common cause of potentially life‐threatening infection. This report describes a relapsing healthcare‐associated Klebsiella pneumoniae meningitis in a 60‐year‐old patient who had SARS‐CoV‐2 infection. During their initial admission for COVID‐19 pneumonitis and treatment with corticosteroids, the patient developed signs and symptoms suggestive of bacterial meningitis. Blood and cerebrospinal fluid cultures confirmed Klebsiella pneumoniae as the causative organism. The patient was treated with a prolonged course of high‐dose meropenem and made an apparent recovery. Four days after hospital discharge, the patient re‐presented critically unwell. Klebsiella pneumoniae was once again isolated from cerebrospinal fluid. During their second admission, the patient deteriorated despite antimicrobial treatment, and life‐sustaining therapies were withdrawn. This case highlights that all COVID‐19 patients receiving immunosuppressive therapy should be monitored for potential opportunistic infection. Prompt recognition and early antimicrobial therapy are key to improving patient outcomes.

Radiographer-led online image guided adaptive radiotherapy: A qualitative investigation of the therapeutic radiographer role

INTRODUCTION

Online MRI guided adaptive radiotherapy (MRIgRT) is resource intensive. To maintain and increase uptake traditional roles and responsibilities may need refining. This novel study aims to provide an in-depth understanding and subsequent impact of the roles required to deliver on-line adaptive MRIgRT by exploring the current skills and knowledge of radiographers.

METHOD

A purposive sampling approach was used to invite radiographers, clinicians and physicists from centres with experience of MRIgRT to participate. Focus Group Interviews were conducted with two facilitators using a semi-structure interview guide (Appendix 1). Four researchers independently familiarised themselves and coded the data using framework analysis. A consensus thematic framework of ptive Radiotherapy codes and categories was agreed and systematically applied.

RESULTS

Thirty participants took part (Radiographers: N = 18, Physicists: N = 9 and Clinicians: N = 3). Three key themes were identified: 'Current MRIgRT', 'Training' and 'Future Practice'. Current MRIgRT identified a variation in radiographers' roles and responsibilities with pathways ranging from radiographer-led, clinician-light-led and MDT-led. The consensus was to move towards radiographer-led with the need to have a robust on-call service heavily emphasised. Training highlighted the breadth of knowledge required by radiographers including MRI, contouring, planning and dosimetry, and treatment experience. Debate was presented over timing and length of training required. Future Practice identified the need to have radiographers solely deliver MRIgRT, to reduce staff present which was seen as a main driver, and time and resources to train radiographers seen as the main barriers.

CONCLUSION

Radiographer-led MRIgRT is an exciting development because of the potential radiographer role development. A national training framework created collaboratively with all stakeholders and professions involved would ensure consistency in skills and knowledge.

IMPLICATIONS FOR PRACTICE

Role development and changes in education for therapeutic radiographers.

P152 Poor sleep quality, individual experiences and increased risk of self-harm – A multi-method study

Introduction

The COVID-19 pandemic has caused significant psychological distress to many people across the globe. Poor sleep quality may be linked to poor mental health and increased suicide ideation. To contextualise the risk factors associated with self-harm or suicidal ideation during the COVID-19 pandemic, this cross-sectional study examined links between poor sleep quality, individual experiences and self-harm risk.

Methods

N=1544 (Mage=44.3y) from 63 countries completed an online survey in March-April 2020. Participants reported their pandemic experiences as free text responses, which were examined quantitatively for frequent word usage using Linguist Inquiry and Word Count software. Pittsburgh Sleep Quality Index assessed poor sleep quality (cut-off score >8). Item-9 of Patient Health Questionnaire-9 measured the risk of self-harm.

Results

Individuals with poor sleep quality (45%) used more negative emotional tone and had greater use of anxiety or money-related words in their comments than good sleepers (all ps<.05). Additionally, 19% of respondents (n=295) reported thoughts of self-harm at least several days a week (3.4% nearly every day). Logistic regression indicated that younger individuals, males, and those feeling isolated or less resilient had 1.2 to 1.5 times greater risk of self-harm (all ps<.001). Poor sleep quality was associated with a two-fold increased risk of self-harm (95%CI=1.5–2.7, p<.0001) after controlling for demographic variables.

Discussion

Poor sleep quality is linked to negative emotionality and increased risk of self-harm during the COVID-19 pandemic. Sleep is a modifiable factor; therefore interventions aimed at addressing sleep disturbances may improve resilience and reduce the risk of self-harm in vulnerable individuals.

The public health community's use of social media for policy advocacy: a scoping review and suggestions to advance the field

OBJECTIVES

This study aimed to investigate the extent and key characteristics of academic research and scholarship on the public health community's use of social media for policy advocacy purposes. This will enable an evaluation of extant research and provide insight into directions for future research.

STUDY DESIGN

This study was a scoping review of academic literature.

METHODS

A scoping review of academic literature published between 1 January 2011 and 31 December 2020 was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework. Boolean searches were conducted using a university library platform, which included databases, such as EBSCO host, Informit, Scopus, and ScienceDirect. Data were extracted using an a priori code frame, and publication, content, and disciplinary characteristics were analysed. The results of coding and screening comparison checks were within acceptable limits.

RESULTS

In total, 2672 works from around the world were identified and screened for inclusion. Twenty-two English language articles were included in the final analysis. The public health community's use of social media for policy advocacy purposes has largely been approached from a health perspective, despite research and scholarship about social media in communication and policy disciplines (among others). Reported research aims or questions emphasised functional rather than theoretical contributions. Most analysed works used empirical or case study-based methods and were produced by authors in Western geographies. Among the health issues discussed, tobacco and tobacco control were discussed most frequently. While recognising issues with social media, most publications framed social media as more of an opportunity than a problem.

CONCLUSIONS

The public health community's use of social media for policy advocacy purposes is an emerging field. There is considerable potential to expand scholarship and research in this field internationally, especially by integrating transdisciplinary knowledge and perspectives and by applying social media to foster policy change around identified global health challenges. Greater representation of authors from institutions in the Global South is also encouraged, as are applied and theoretical contributions.

Recruitment of Low-wage Workers for a Time-Sensitive Natural Experiment to Evaluate a Minimum Wage Policy: Challenges and Lessons Learned

Natural experiments are often used for answering research questions in which randomization is implausible. Effective recruitment strategies are well documented for observational cohort studies and clinical trials, unlike recruitment methods for time-sensitive natural experiments. In this time-sensitive study of the impact of a minimum wage policy, we aimed to recruit 900 low-wage workers in Minneapolis, Minnesota and Raleigh, North Carolina. We present our recruitment strategies, challenges, and successes for participant screening and enrollment of a difficult-to-reach population.

The gut-microbiome-endocannabinoid axis and anhedonia/amotivation: A mediation analysis in a general population cohort

Introduction

General-population studies investigating the biological correlates of anhedonia/amotivation might be informative for treatment breakthroughs for a number of clinical conditions. Reduced gut-microbial diversity might lead to an anhedonic/amotivational syndrome (“sickness behaviour”). However, how gut-microbial diversity contribute to this clinical phenotype is a key gap in knowledge. We hypothesised the endocannabinoid system would be at play.

Objectives

We tested the hypothesis that the endocannabinoid system mediates the association between gut-microbial diversity and anhedonia/amotivation

Methods

Secondary data analysis on 786 volunteer twins (TwinsUK). Measures of gut-microbiome, faecal endocannabinoid metabolites, and anhedonia/amotivation were collected over five years. To test our hypothesis we used a multilevel mediation model using alpha diversity as predictor, faecal levels of the endocannabinoid palmitoylethanolamide (PEA) as mediator, and anhedonia/amotivation as outcome. Analyses were adjusted for obesity, diet, antidepressants, and sociodemographic covariates.

Results

Mean age was 65.2±7.6; 27% were obese and 4.7% were on antidepressants. Alpha diversity was significantly associated with anhedonia/amotivation (β=-0.37; 95%CI: -0.71 to -0.03; P=0.03). Faecal PEA levels mediated this association: the indirect effect was significant (β=-0.13; 95%CI: -0.24 to -0.01; P=0.03), as was the total effect (β=-0.38; 95%CI: -0.72 to -0.04; P=0.03). The direct effect of alpha diversity on anhedonia/amotivation was attenuated fully

Conclusions

We provided the first evidence showing that the association between gut-microbial features and anhedonia/amotivation is mediated by the endocannabinoid system. These findings shed light on a new therapeutic target in an area of unmet clinical need.

Disclosure

No significant relationships.

Patient deprivation and perceived scan burden negatively impact the quality of whole-body MRI

AIM

To evaluate the association between the image quality of cancer staging whole-body magnetic resonance imaging (WB-MRI) and patient demographics, distress, and perceived scan burden.

MATERIALS AND METHODS

A sample of patients recruited prospectively to multicentre trials comparing WB-MRI with standard scans for staging lung and colorectal cancer were invited to complete two questionnaires. The baseline questionnaire, administered at recruitment, collated data on demographics, distress and co-morbidity. The follow-up questionnaire, completed after staging investigations, measured perceived WB-MRI scan burden (scored 1 low to 7 high). WB-MRI anatomical coverage, and technical quality was graded by a radiographic technician and grading combined to categorise the scan as "optimal", "sub-optimal" or "degraded". A radiologist categorised 30 scans to test interobserver agreement. Data were analysed using the chi-square, Fisher's exact, t-tests, and multinomial regression.

RESULTS

One hundred and fourteen patients were included in the study (53 lung, 61 colorectal; average age 65.3 years, SD=11.8; 66 men [57.9%]). Overall, 45.6% (n=52), scans were classified as "optimal" quality, 39.5% (n=45) "sub-optimal", and 14.9% (n=17) as "degraded". In adjusted analyses, greater deprivation level and higher patient-reported scan burden were both associated with a higher likelihood of having a sub-optimal versus an optimal scan (odds ratio [OR]: 4.465, 95% confidence interval [CI]: 1.454 to 13.709, p=0.009; OR: 1.987, CI: 1.153 to 3.425, p=0.013, respectively). None of the variables predicted the likelihood of having a degraded scan.

CONCLUSIONS

Deprivation and patients' perceived experience of the WB-MRI are related to image quality. Tailored protocols and individualised patient management before and during WB-MRI may improve image quality.

African-Caribbean Cancer Consortium Scientific and Training Conference 2017

The sixth International African-Caribbean Cancer Consortium (AC3) Conference was held 6-9 October 2017 in Miami, Florida, U.S.A. The conference was open to all researchers, trainees, clinical and public health professionals, and community members, and served as an international hub for the United States, the Caribbean, and Africa. Sessions included AC3 collaboration meetings, cancer surveillance and research skills training workshops, and a community cancer prevention conference.

6LiF:ZnS(Ag) Neutron Detector Performance Optimized Using Waveform Recordings and ROC Curves

We used Gaussian separation and receiver operating characteristic (ROC) curves to optimize the neutron sensitivity and gamma rejection of an ultra-thin ⁶LiF:ZnS(Ag)-scintillator-based neutron detector paired with a silicon photomultiplier (SiPM). We recorded the waveforms while operating the detector in a monochromatic cold neutron beam and in the presence of isotopic ¹³⁷Cs and ⁶⁰Co gamma sources. We used a two-window charge comparison (CC) pulse-shape discrimination (PSD) technique to distinguish the neutron capture events from other types of signals. By feeding the recorded waveforms through variants of this algorithm, it was possible to optimize the duration of the integration windows [(0-100 ns) for the prompt window and (100-2300 ns)] for the delayed window. We then computed the detector's ROC curve from waveform recordings and compared that with the experimental performance. We also used this procedure to compare a series of detector configurations to select the optimal bias voltage for the SiPM photosensor.