Mass-manufacturable scintillation-based optical fiber dosimeters for brachytherapy.

Scintillation-based fiber dosimeters are a powerful tool for minimally invasive localized real-time monitoring of the dose rate during Low Dose Rate (LDR) and High Dose Rate (HDR) brachytherapy (BT). This paper presents the design, fabrication, and characterization of such dosimeters, consisting of scintillating sensor tips attached to polymer optical fiber (POF). The sensor tips consist of inorganic scintillators, i.e. Gd2O2S:Tb for LDR-BT, and Y2O3:Eu+4YVO4:Eu for HDR-BT, dispersed in a polymer host. The shape and size of the tips are optimized using non-sequential ray tracing simulations towards maximizing the collection and coupling of the scintillation signal into the POF. They are then manufactured by means of a custom moulding process implemented on a commercial hot embossing machine, paving the way towards series production. Dosimetry experiments in water phantoms show that both the HDR-BT and LDR-BT sensors feature good consistency in the magnitude of the average photon count rate and that the photon count rate signal is not significantly affected by variations in sensor tip composition and geometry. Whilst individual calibration remains necessary, the proposed dosimeters show great potential for in-vivo dosimetry for brachytherapy.

Characterisation of a Silicon Photomultiplier Based Oncological Brachytherapy Fibre Dosimeter.

Source localisation and real-time dose verification are at the forefront of medical research in brachytherapy, an oncological radiotherapy procedure based on radioactive sources implanted in the patient body. The ORIGIN project aims to respond to this medical community's need by targeting the development of a multi-point dose mapping system based on fibre sensors integrating a small volume of scintillating material into the tip and interfaced with silicon photomultipliers operated in counting mode. In this paper, a novel method for the selection of the optimal silicon photomultipliers to be used is presented, as well as a laboratory characterisation based on dosimetric figures of merit. More specifically, a technique exploiting the optical cross-talk to maintain the detector linearity in high-rate conditions is demonstrated. Lastly, it is shown that the ORIGIN system complies with the TG43-U1 protocol in high and low dose rate pre-clinical trials with actual brachytherapy sources, an essential requirement for assessing the proposed system as a dosimeter and comparing the performance of the system prototype against the ORIGIN project specifications.

The Running Injury Continuum: A qualitative examination of recreational runners' description and management of injury.

INTRODUCTION: A critical step in understanding and preventing running-related injuries (RRIs) is appropriately defining RRIs. Current definitions of RRIs may not represent the full process of injury development, failing to capture lower levels of injury that many athletes continue to train through. Understanding runners' description and management of the injury development process may allow for a more appropriate examination of all levels of injury. This study aimed to examine recreational runners' description and management of the injury development process. METHODS: A qualitative focus group study was undertaken. Seven semi-structured focus groups with male (n = 13) and female (n = 18) recreational runners took place. Focus groups were audio and video recorded, and transcribed verbatim. Transcripts were reflexively thematically analysed. A critical friend approach was taken to data coding. Multiple methods of trustworthiness were executed. RESULTS: Runners describe injury on a nine-level continuum, ranging from injury-free to career-ending injury. There are lower and higher levels of injury. Each level of injury is described across four categories of descriptors; physical description, outcome (effect on running and daily life), psychological description, and management. CONCLUSION: The Running Injury Continuum is a tool that can be used for injury surveillance (for healthcare professionals and researchers) and for research investigating RRI risk factors. Healthcare professionals, researchers and coaches must ensure they monitor the development of all levels of RRIs, across all categories of descriptors. Runners need to be educated regarding appropriate self-management strategies for lower level injuries, with access to evidence-based information being a critical management tool.

Injury prevention in ladies Gaelic football referees: Understanding the barriers, facilitators, and preferences of referees.

OBJECTIVES: The injury prevalence in Gaelic games refereeing is high, however few are adopting injury prevention programmes. This study aims to identify the barriers and facilitators to injury prevention strategy success and determine Ladies Gaelic Football referees' preferences for injury prevention strategies and education. DESIGN: Semi-structured interviews were conducted with 11 Ladies Gaelic Football referees (10 men, 1 woman). Two were club level, two were provincial level and 7 were national level referees. Interviews were audio-recorded, transcribed verbatim, and reflexive thematic analysis was completed. This analysis involved examining the data repeatedly and gradually developing sub-themes, themes, and categories related to each core concept. RESULTS: The barriers to injury prevention success included negative attitudes, accessibility issues, lack of education, the state of refereeing and undesirable injury prevention strategy characteristics. Injury prevention promotion, suitable strategy characteristics and open communication were believed to facilitate success. Referees gave their preferences for injury prevention programmes, strategy logistics, and stakeholder roles along with their preferred topics, delivery, educators, characteristics, rollout, and timing for injury prevention education. CONCLUSIONS: Reducing referee injury is critical to the success of Ladies Gaelic Football and other community sports. Governing bodies must develop and support injury prevention programmes and education for referees. These should be designed according to referees' preferences and consider the barriers and facilitators referees have identified to maximise adoption.

The Design and Implementation of a Novel Mental Health Literacy Educational Intervention Program in Gaelic Footballers.

CONTEXT: Lack of education, stigma, and negative self-attitudes are key barriers to help-seeking in Gaelic footballers. With the prevalence of mental health issues in Gaelic footballers and the increased risk of experiencing mental health challenges after injury, mental health literacy (MHL) interventions are necessary. OBJECTIVES: To design and implement a novel MHL educational intervention program in Gaelic footballers. DESIGN: Controlled laboratory study. SETTING: Online. PATIENTS OR OTHER PARTICIPANTS: Elite and subelite Gaelic footballers divided into intervention (n = 70; age = 25.1 ± 4.5 years) and control (n = 75; age = 24.4 ± 6.0 years) groups. In the intervention group, 85 participants were recruited, but 15 dropped out after completing baseline measures. INTERVENTIONS: A novel educational intervention program, "GAA [Gaelic Athletic Association] and Mental Health-Injury and a Healthy Mind," was designed to address the key components of MHL and was underpinned by the Theory of Planned Behavior and the Help-Seeking Model. The intervention was implemented online via a brief 25-minute presentation. MAIN OUTCOME MEASURES: Measures of stigma, help-seeking attitudes, and MHL were completed by the intervention group at baseline, immediately after viewing the MHL program, and at 1 week and 1 month after the intervention. The control group completed the measures at similar time points. RESULTS: Stigma decreased, and attitudes toward help-seeking and MHL increased in the intervention group from baseline to after the intervention (P < .05), with significant differences sustained at 1-week and 1-month follow-ups. Our results showed differences in stigma, attitudes, and MHL between groups across time points. Intervention participants provided positive feedback, and the program was appraised as informative. CONCLUSIONS: Remote online delivery of a novel MHL educational program can effectively decrease mental health stigma, improve attitudes toward help-seeking, and increase the recognition and knowledge of mental health issues. Gaelic footballers with improved MHL may be better equipped to manage their mental health and cope with stressors, leading to improved mental health outcomes and overall mental well-being.

A qualitative examination of injury prevention strategy and education in Ladies Gaelic football: Understanding the preferences of players and coaches.

The high rates of injury in Ladies Gaelic football impact the wellbeing of players and are a major financial burden for the Ladies Gaelic Football Association. Effective injury prevention programmes have been developed for Gaelic games, but these are not currently widely adopted. The aim of this study was to qualitatively investigate adult Ladies Gaelic football players and coaches' preferences for injury prevention strategies and injury prevention education using a constructivist grounded-theory approach. Semi-structured interviews were conducted with 23 currently active Ladies Gaelic football coaches and adult players. The core strategy preferences discussed by participants were the properties of an injury prevention programme, the role of stakeholders, strategy logistics and the need for guidance and support. If the uptake and long-term adoption of an injury prevention programme is to be maximised, the preferences of the players and coaches who will ultimately utilise the programme must be understood and integrated into a wider implementation strategy developed around their needs. For education preferences, the core categories identified were the focus of education, who needs education, the format, educator, roll-out strategy, and time required. Future educational strategies must incorporate the preferences of stakeholders into their design if they are to be successful in spreading injury prevention knowledge and achieving change. To give injury prevention strategies, programmes, and education the best chances at successful adoption, it is crucial that the preferences of end-users are addressed and implemented.

Barriers and facilitators to injury prevention in ladies Gaelic football: A qualitative study.

OBJECTIVES: Injury rates have remained high in ladies Gaelic football over the last decade and treatment costs continue to increase significantly. Injury prevention programmes are a proposed solution and their efficacy has been demonstrated in Gaelic games, however, anecdotally their adoption is low. The aim of this study was to determine the barriers and facilitators to uptake, implementation, and long-term adoption of an injury prevention strategy for adult Ladies Gaelic football players and coaches. DESIGN: Semi-structured interviews were conducted with 23 participants (13 coaches, 10 players). Four coaches were at intercounty level and nine were at club level, while two players competed at intercounty and club level and eight played solely at club level. The interviews were audio-recorded, transcribed verbatim and thematically analysed. RESULTS: Stakeholder attitudes, accessibility, education, communication, and injury prevention programme characteristics were perceived as key barriers to an injury prevention strategy succeeding. Injury prevention promotion, injury prevention programme characteristics, leadership, and communication, were identified as the main factors that would facilitate the success of a strategy. CONCLUSIONS: By utilising the views of stakeholders, the initial uptake, adherence, and long-term adoption of an injury prevention strategy in Ladies Gaelic football may be maximised.

A qualitative examination of the factors affecting the adoption of injury focused wearable technologies in recreational runners.

PURPOSE: Understanding the perceived efficacy and ease of use of technologies will influence initial adoption and sustained utilization. The objectives of this study were to determine the metrics deemed important by runners for monitoring running-related injury (RRI) risk, and identify the facilitators and barriers to their use of injury focused wearable technologies. METHODS: A qualitative focus group study was undertaken. Nine semi-structured focus groups with male (n = 13) and female (n = 14) recreational runners took place. Focus groups were audio and video recorded, and transcribed verbatim. Transcripts were thematically analysed. A critical friend approach was taken to data coding, and multiple methods of trustworthiness were executed. RESULTS: Excessive loading and inadequate recovery were deemed the most important risk factors to monitor for RRI risk. Other important factors included training activities, injury status and history, and running technique. The location and method of attachment of a wearable device, the design of a smartphone application, and receiving useful injury-related information will affect recreational runners' adoption of injury focused technologies. CONCLUSIONS: Overtraining, training-related and individual-related risk factors are essential metrics that need to be monitored for RRI risk. RRI apps should include the metrics deemed important by runners, once there is supporting evidence-based research. The difficulty and/or ease of use of a device, and receiving useful feedback will influence the adoption of injury focused running technologies. There is a clear willingness from recreational runners to adopt injury focused wearable technologies whilst running.

Barriers and Facilitators to Mental Health Help-Seeking in Elite Gaelic Footballers Post-Injury: A Qualitative Study.

Purpose: Injury can exacerbate mental health issues in athletes. However, the prevalence of mental health issues is not equivalent to the rate of professional help-seeking, with reluctance to seek-help acknowledged as one of the greatest obstacles in efficient management of mental health issues. The current study aimed to examine perceived barriers and facilitators to professional mental health help-seeking in elite male and female Gaelic footballers post-injury. Methods: Male (n = 14) and female (n = 12) elite Gaelic footballers, with a history of moderate or severe injury, were recruited to participate in a focus group. Group discussions began with a written task where participants noted perceived barriers to help-seeking followed by a group discussion of these barriers. Following discussion, participants ranked identified barriers in order of those perceived as most important in stopping a player from seeking help when experiencing mental health issues post-injury. All three tasks were repeated for help-seeking facilitators. Focus groups were audiotaped, transcribed and thematically analyzed. Results: Lack of education, stigma, negative attitudes to help-seeking and accessibility issues were identified as key barriers to help-seeking among elite Gaelic footballers. Education, the attitudes and actions of others and accessibility were perceived as factors facilitating help-seeking. Conclusions: Given the negative psychological responses that can accompany injury, there is a need for facilitation and encouragement of help-seeking among players experiencing mental health issues post-injury. Interventions for reducing the barriers to help-seeking identified in the current study are necessary.

Dosimetric Application of Phosphorus Doped Fibre for X-ray and Proton Therapy.

Phosphorous-doped silica optical fibres with a core diameter of 4 µm were tested in X-ray and proton fields for application in cancer therapy dosimetry. Specifically, the radiation-induced attenuation was investigated in terms of linearity in deposited dose in 15 MV and 6 MV photons and 74 MeV protons, as well as Bragg-peak detection along the proton track. Fibres were found to demonstrate linear relative dose response in both radiation modalities, but possible saturation did occur at the high linear energy transfer of the Bragg peak. This demonstrates the possibility to use these fibres as a relative dosimeter for radiation therapy applications.

Fear Avoidance Following Musculoskeletal Injury in Male Adolescent Gaelic Footballers.

CONTEXT: Participating in Gaelic football provides a wealth of benefits, but a risk of musculoskeletal injury also exists. Injury is associated with physical consequences, including pain, discomfort, loss of function, time absent from school/sport, and considerable medical expenses, along with placing undue pressure on emergency services and hospital staff. Concurrent psychological consequences, such as fear avoidance, can also occur, causing psychological distress. There is a current dearth of available research examining the psychology of injury in male adolescent Gaelic footballers. OBJECTIVE: To examine fear avoidance postinjury in male adolescent Gaelic footballers, the effect of pain, time loss, injury severity, and previous injury on the extent of fear avoidance, and the usefulness of a modified Athlete Fear Avoidance Questionnaire (AFAQ) as a screening tool for predicting injury. DESIGN: Prospective cohort study. SETTING: Recreational clubs. PARTICIPANTS: A total of 97 male adolescent club Gaelic footballers (13.4 [1.1] y). INTERVENTIONS: Musculoskeletal injuries sustained during participation in Gaelic football, defined as any injury sustained during training or competition causing restricted performance or time lost from play, were assessed and recorded weekly by a certified athletic and rehabilitation therapist. Injuries requiring time loss from participation were classed as time-loss injuries. Injury characteristics that included type, nature, location, severity, and pain were recorded. MAIN OUTCOME MEASURES: Injured players completed the AFAQ, a measure of injury-related fear avoidance following injury assessment (AFAQ1). With time-loss injuries, the AFAQ was completed again (AFAQ2) prior to return to play. Modified AFAQ was completed at baseline. RESULTS: Twenty-two injuries were recorded during the season with fear avoidance evident postinjury that significantly decreased before returning to play. Fear avoidance postinjury was higher in those with greater pain but time loss, injury severity, and previous injury did not significantly affect the extent of fear avoidance. Baseline fear avoidance did not predict injury. CONCLUSIONS: Psychological rehabilitation is recommended for managing postinjury psychological distress in male adolescent Gaelic footballers.

Are internal load measures associated with injuries in male adolescent Gaelic football players?

This study aimed to examine internal loads in male adolescent Gaelic footballers and their association with musculoskeletal injury. Written training diaries were completed by 97 male adolescent Gaelic footballers weekly and injuries, defined as any injury sustained during training or competition causing restricted performance or time lost from play, were assessed by a Certified Athletic Therapist. Daily load was determined for each player (session rating of perceived exertion by session duration) and summed to give weekly load. Univariate and multiple logistic regressions were conducted to determine the association with injury. Twenty-two injuries were recorded with match injuries significantly more common than training injuries. Periodic variations in weekly load and injuries were evident throughout the season. Univariate analysis identified weekly load (OR = 2.75; 95%CI = 1.00-7.59), monotony (OR = 4.17; 95%CI = 1.48-11.72) and absolute change in load (OR = 3.27; 95%CI = 1.15-9.32) greater than the team average were significant injury risk factors. Multiple logistic regression with 2-weekly and 3-weekly cumulative loads, absolute change, monotony, strain, ACWR and age as independent variables identified internal load measures (monotony, strain and absolute change) were associated with injury with high specificity (96.0%) but low sensitivity (25.0%). The findings highlight the need to monitor team and individual loads to avoid sudden week-to-week changes or excessive weekly loads. Open communication between players, parents, coaches and sports medicine clinicians enables effective load monitoring that can reduce injury risk and may subsequently minimise dropout, improve team success and overall sport enjoyment and promote life-long sports participation.

Benchmarking a novel inorganic scintillation detector for applications in radiation therapy.

PURPOSE: The aim of this study was to investigate the contribution of Cerenkov radiation to the overall signal measured with a novel inorganic scintillating detector (ISD). METHODS: An ISD based on terbium doped gadolinium oxysulphide (Gd2O2S:Tb) was used. A hyperspectral technique separated the Cerenkov signal from the radioluminescence (RL) signal of the ISD. The relative contribution of Cerenkov radiation was evaluated under different conditions. The efficiency of using simple spectral correction to reduce the Cerenkov contribution was quantified. Other experiments investigated were the dose-per-pulse dependence observed in our previous study and the absorbed-dose energy dependence when acquiring percentage depth dose curves using Monte Carlo (MC) simulations. RESULTS: The maximum relative contribution of Cerenkov radiation was 2.10% for a 10 × 10 cm2 field at 10 cm depth. However, this percentage increased to 24% when the ISD was 7 cm out of field and exposed to a 10 × 10 cm2 field. Using 15 nm and 5 nm band-pass filters reduced the Cerenkov contribution across all experimental conditions by a maximum of 75% and 82%, respectively. The MC simulation results show discrepancies between the measured and simulated PDD profiles using the Gd2O2S:Tb scintillator at depth. CONCLUSION: This study showed that while Gd2O2S:Tb ISD provides high-signal intensity, the contribution of Cerenkov radiation under specific conditions can be significant. However, narrow band-pass filters can reduce the Cerenkov signal to a negligible level. The MC simulations suggest mechanisms other than the stem effect and the absorbed-dose energy dependence influence the response of the Gd2O2S:Tb scintillator measurements at depth.

An Analytical Model for Describing the Power Coupling Ratio between Multimode Fibers with Transverse Displacement and Angular Misalignment in an Optical Fiber Bend Sensor.

The power coupling ratio between step-index multimode fibers caused by combined transversal and angular misalignment is calculated. A theoretical description of the coupling efficiency between two optical fibers based on geometrical optics is provided. The theoretical calculations are collaborated by experiments, determining the power coupling ratio between three output fibers with an axial offset and angular misalignment with a single input fiber. The calculation results are in good agreement with experimental results obtained using a previously fabricated optical fiber sensor for monitoring physiological parameters in clinical environments. The theoretical results are particularly beneficial for optimizing the design of optical fiber bending sensors that are based on power coupling loss (intensity) as the measurement interrogation requires either axial displacement, angular misalignment, or both.

A Validation Study of a Polymer Optical Fiber Sensor for Monitoring Lumbar Spine Movement.

This study aims to investigate the validity and reliability of a novel plastic optical fiber (POF) sensor, which was developed to measure the angles of flexion, extension and lateral bend at the lumbar region. The angles of flexion, extension and lateral bend for a standing position were measured simultaneously using both the novel POF sensor of this investigation and the commercial Biometrics goniometer instrument. Each movement had two steps of bending which were 10° and 20° based on inclinometer readings. The POF sensor had good intra-rater reliability (Intraclass correlation coefficient, ICC = 0.61 to 0.83). Bland⁻Altman plots were used to study the agreement using these two sensors. There were proportional differences and bias between the POF sensor and Biometrics goniometer, as the zero points did not lie in the percentage difference region in the Bland⁻Altman plots. The proportional difference between these two likely reflects the different sizes and thus, measurement regions of the two sensors. There was also strong correlation between the two sensors (r > 0.77). Hence, the POF sensor could be of potential utility in measuring lumbar range of motion (ROM) in a manner which is minimally invasive, and where discrete sections of the spine are under specific investigation.

Characterization of scintillating X-ray optical fiber sensors.

The paper presents a set of tests carried out in order to evaluate the design characteristics and the operating performance of a set of six X-ray extrinsic optical fiber sensors. The extrinsic sensor we developed is intended to be used as a low energy X-ray detector for monitoring radiation levels in radiotherapy, industrial applications and for personnel dosimetry. The reproducibility of the manufacturing process and the characteristics of the sensors were assessed. The sensors dynamic range, linearity, sensitivity, and reproducibility are evaluated through radioluminescence measurements, X-ray fluorescence and X-ray imaging investigations. Their response to the operating conditions of the excitation source was estimated. The effect of the sensors design and implementation, on the collecting efficiency of the radioluminescence signal was measured. The study indicated that the sensors are efficient only in the first 5 mm of the tip, and that a reflective coating can improve their response. Additional tests were done to investigate the concentricity of the sensors tip against the core of the optical fiber guiding the optical signal. The influence of the active material concentration on the sensor response to X-ray was studied. The tests were carried out by measuring the radioluminescence signal with an optical fiber spectrometer and with a Multi-Pixel Photon Counter.

Plastic optical fibre sensor for spine bending monitoring with power fluctuation compensation.

This paper presents the implementation of power fluctuation compensation for an intensity-based optical fibre bending sensor aimed at monitoring human spine bending in a clinical environment. To compensate for the light intensity changes from the sensor light source, a reference signal was provided via the light reflection from an aluminum foil surface fixed at a certain distance from the source fibre end tips. From the results, it was found that the investigated sensor compensation technique was capable of achieving a 2° resolution for a bending angle working range between 0° and 20°. The study also suggested that the output voltage ratio has a 0.55% diversion due to input voltage variation between 2.9 V and 3.4 V and a 0.25% output drift for a 2 h measurement. With the achieved sensor properties, human spine monitoring in a clinical environment can potentially be implemented using this approach with power fluctuation compensation.

The diagnostic accuracy of endoscopic ultrasound in suspected biliary obstruction and its impact on endoscopic retrograde cholangiopancreatography burden in real clinical practice: a consecutive analysis.

BACKGROUND AND AIMS: Performing endoscopic ultrasound (EUS) before endoscopic retrograde cholangiopancreatography (ERCP) has been described to be useful in cases of suspected biliary obstruction where EUS can triage patients for ERCP. We aimed to determine the diagnostic accuracy of EUS and its impact on ERCP burden in real clinical practice. We also evaluated the safety and efficacy of EUS+ERCP in a single endoscopic session. PATIENTS AND METHODS: Four hundred and eighteen consecutive patients with suspected but unexplained biliary obstruction referred for EUS before possible ERCP were evaluated. The diagnostic accuracy of EUS and its value in predicting the need for ERCP were determined. EUS established whether pancreaticobiliary disorder (PBD) was present and whether therapeutic ERCP was required. These decisions were matched with ERCP findings, histology, clinical course, and follow-up. Where ERCP was indicated, it was performed in the same endoscopic session. RESULTS: EUS was performed in 412/418 patients (feasibility 98.5%), and ERCP was considered necessary in 64% (ERCP avoided in 36%). The single-session EUS and ERCP was safe and effective (264 patients). The diagnostic accuracy of EUS was as follows: choledocholithiasis 99%, malignant strictures 90%, and benign strictures 92%. EUS showed pathology in 42% of patients who had a nondilated biliary system at initial investigations. When EUS indicated a normal common bile duct (n=119), this had a 100% positive predictive value for non-necessity for ERCP. The median overall follow-up period was 12 months (range 6-34 months). CONCLUSION: EUS demonstrated high diagnostic accuracy in this mixed group of PBD. This accurately guided ERCP need and avoided unnecessary ERCP in 36%. EUS and ERCP in the same endoscopic session for the evaluation and management of PBD is technically feasible, with safety and efficacy profiles equivalent to that of each procedure performed independently in different sessions.

Experimental investigations of microwave plasma UV lamp for food applications.

The food industry is keen to have new techniques that improve the safety and/or shelf life of food products without the use of preservatives. There is considerable interest in developing UV light and ozone (O3) treatments to enhance shelf life. A microwave radiation device that is a novel source of germicidal UV and O3 suitable for the food industry has been developed, which offers speed, cost and energy benefits over existing sources. With this system comes the need to monitor a number of conditions, primarily UV intensity and ozone gas concentrations. The effectiveness of intense UV exposure for short periods of time was assessed on different microorganisms. Culture plates were exposed to a range of doses of UV-C light, and the reduction in numbers of surviving microorganisms was recorded The results on the biocidal capacity of the microwave generated UV light are presented.