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Asian Pacific Journal of Cancer... Jun 2024The goal of this study is to determine the accuracy of the PTW Beamscan program in determining the inflection point from Flattening Filter Free Beam Profile utilizing...
OBJECTIVE
The goal of this study is to determine the accuracy of the PTW Beamscan program in determining the inflection point from Flattening Filter Free Beam Profile utilizing Multiple Detectors.
METHODS
True Beam Linear Accelerator with 6FFF and 10FFF Photon Energies and 10 cm, 15 cm and 20 cm Field Sizes were used for this study. Profile measurements were taken with PTW's 729, 1,500, and 1,600 and the Starcheck system, the Pinpoint 3D with Beamscan system, and Linac's EPID. The first-order derivative was utilized in both the Excel spreadsheet and Beamscan software to analyse raw measured data to locate inflection point and the FWHM was calculated. The accuracy of inflection points and FWHM between the Excel sheet calculation and the software program were investigated.
RESULTS
For 10X10 cm2 in the 729 Array, the greatest differences in FWHM were 5.16 mm and 5.04 mm for the X6 FFF and X10 FFF Energies, respectively. The largest difference was 2.26 mm for 1,600 SRS arrays with a 15×15 cm2 field size. The difference in FWHM between Manual and software analysis for 10X10 cm2 and 20X20 cm2 Field Sizes is in decreasing order for detectors from 729, 1,500, 1,600 SRS, Starcheck, Pinpoint 3D, and EPID. In contrast, there is no climbing or declining pattern detected in the difference in Field Width for the 15×15 cm2 Field Size. Similarly, for all detectors except the 1,600 SRS array, the peak of the first-order derivative occurs at the chamber position for a 15X15 cm2 field size.
CONCLUSION
The higher resolution of measurement yields more accuracy in inflection point and the FWHM. Irrespective of measurement resolution, the Beamscan software provided the FWHM closer to the respective nominal Field Size. Out of all detectors, results obtained with Excel Starcheck and EPID are good in agreement with values obtained by the software analysis. Thus, it is shown that Beamscan software is so accurate in determining inflection point of a FFF beam profile and used for routine profile analysis.
Topics: Software; Particle Accelerators; Humans; Radiotherapy Planning, Computer-Assisted; Photons; Radiotherapy Dosage; Radiometry; Algorithms
PubMed: 38918681
DOI: 10.31557/APJCP.2024.25.6.2177 -
Asian Pacific Journal of Cancer... Jun 2024The aim of this study was to investigate the detector size effect on small-field dosimetry and compare the performance of 6MV WFF/FFF techniques. (Comparative Study)
Comparative Study
PURPOSE
The aim of this study was to investigate the detector size effect on small-field dosimetry and compare the performance of 6MV WFF/FFF techniques.
METHODS
We investigated the detector size effect on small-field dosimetry and compared the performance of 6MV WFF/FFF techniques. PDD, profile curves, and absorbed dose were measured in water under reference conditions with 6MV (WFF/FFF) techniques. We employed Farmer FC65-P, CC13, CC01, and IBA Razor diode, with Versa Lineac. Subsequently, we replicated this assessment for small-fields under 5cmx5cm dimensions.
RESULTS
For both 6MV WFF/FFF, significant dose differences (Dmax=1.47cm), were ±4.55%, ±6.7, ±12.75% and ±33.3% for 4cmx4cm, 3cmx3cm, 2cmx2cm, and 1cmx1cm, respectively. The average difference relative to D10 was observed to be ±4.66%, ±5.73%, ±6.58%, and ±8.75% for the previous field sizes. Differences between WFF/FFF are neglected values at all field sizes>2.3%, also, the output of the largest detector FC65-P is lower at 55% in the smallest field size. Variation in the profile doesn't exceed a difference of >5% in flatness between WFF/FFF at depth10cm, across all fields, while symmetry is >1%, but radiation output is considerably lower at 55% for FC65-P chamber in 2cmx2cm, 1cmx1cm compared to the CC01 chamber and Razor diode. Significant differences in 1cmx1cm, where FC65-P chamber exhibits around 49% difference compared to Razor diode with 6MV (WFF/FFF). Conclusions: Significant differences were observed in doses with various detectors. Detector-size influences the dose. WFF/FFF techniques show no major differences in small-fields dosimetry. Utilize some situations the advantage of FFF boasting a higher dose rate, consequently reducing treatment time to half.
Topics: Humans; Radiometry; Radiotherapy Dosage; Particle Accelerators; Radiotherapy Planning, Computer-Assisted; Phantoms, Imaging
PubMed: 38918673
DOI: 10.31557/APJCP.2024.25.6.2105 -
Asian Pacific Journal of Cancer... Jun 2024The study aimed to validate a method for minimizing phase errors by combining full-length lung 4DCT (f4DCT) scans with shorter tumor-restricted 4DCT (s4DCT) scans. It...
PURPOSE
The study aimed to validate a method for minimizing phase errors by combining full-length lung 4DCT (f4DCT) scans with shorter tumor-restricted 4DCT (s4DCT) scans. It assessed the feasibility of integrating two scans one covering the entire phantom length and the other focused on the tumor area. The study also evaluated the impact of Maximum Intensity Projection (MIP) volume and imaging dose for different slice thicknesses (2.5mm and 1.25mm) in both full-length and short target-restricted 4DCT scans.
METHODS
The study utilized the Quasar Programmable Respiratory Motion Phantom, simulating tumor motion with a variable lung insert. The setup included a tumor replica and a six-dot IR reflector marker on the breathing platform. The objective was to analyze volume differences in fMIP_2.5mm compared to sMIP_1.25mm within their respective 4D_MIP CT series. This involved varying breathing periods (2.5s, 3.0s, 4.0s, and 5.0s) and longitudinal tumor sizes (6mm, 8mm, and 10mm). The study also assessed exposure time and expected CTDIvol of s4D_2.5mm and s4D_1.25mm for different breathing periods (5.0s to 2.0s) in the sinusoidal wave motion of the six-dot marker on the breathing platform.
RESULTS
Conducting two consecutive 4DCT scans is viable for patients with challenging breathing patterns or when the initial lung tumor scan is in close proximity to the tumor location, eliminating the need for an additional full-length 4DCT. The analysis involves assessing MIP volume, imaging dose (CTDIvol), and exposure time. Longitudinal tumor shifts for 6mm are [16.6-17.2] in fMIP_2.5mm and [16.8-17.5] in sMIP_1.25mm, for 8mm [17.2-18.3] in fMIP_2.5mm and [17.8-18.4] in sMIP_1.25mm, and for 10mm [19-19.9] in fMIP_2.5mm and [19.4-20] in sMIP_1.25mm (p≥ 0.005), respectively.
CONCLUSION
The Quasar Programmable Respiratory Motion Phantom accurately replicated varied breathing patterns and tumor motions. Comprehensive analysis was facilitated through detailed manual segmentation of Internal Target Volumes and Internal Gross Target Volumes.
Topics: Humans; Four-Dimensional Computed Tomography; Phantoms, Imaging; Respiration; Feasibility Studies; Lung Neoplasms; Radiotherapy Planning, Computer-Assisted
PubMed: 38918671
DOI: 10.31557/APJCP.2024.25.6.2089 -
Asian Pacific Journal of Cancer... Jun 2024Exposure to noise by generation of free radicals causes oxidative stress in body. The aim of this study was the evaluation of oxidative stress in workers who have used...
BACKGROUND AND OBJECTIVE
Exposure to noise by generation of free radicals causes oxidative stress in body. The aim of this study was the evaluation of oxidative stress in workers who have used hearing protection devices during working time.
MATERIAL AND METHOD
Pressing workers (n=24) of a home appliance industry were studied using hearing protection devices to reduce noise exposure. Twenty two office staff (without exposure to noise) were considered as a control group. Two groups were matched for age, work experience and smoking. Exposure to noise was measured by dosimeter method at workstations. By obtaining 3 ml blood sample, Malondialdehyde levels, Thiol groups and total antioxidant capacity were evaluated in all subjects.
RESULTS
Exposure to sound pressure level in pressing workers by considering the noise reduction factor of the earplug was observed in 77.65 dB with minimum 75.1 dB and Maximum 81.22 dB. Plasma thiol groups (0.076 (0.041-0.119) vs (0.110 (0.076-0.197), mmol/l P =0.0001) and total antioxidant capacity (361.33± 54.65 vs 414.14± 96.82, µmol/ml P = 0.026) in pressing workers significantly decreased than control group. Pearson correlation showed significant results between exposure to noise and oxidative stress parameters.
CONCLUSION
Exposure to noise wave cause oxidative stress in different site of body. Oxidative stress is an intermediate way for different disease due to noise exposure. Reducing of noise exposure by earplug in pressing workers is not efficient protection for oxidative stress generation. Therefore, hearing protection devices are not a barrier to the harmful effects of noise in occupational exposure.
Topics: Humans; Oxidative Stress; Occupational Exposure; Adult; Male; Noise, Occupational; Case-Control Studies; Ear Protective Devices; Hearing Loss, Noise-Induced; Antioxidants; Middle Aged; Follow-Up Studies; Malondialdehyde; Female; Occupational Diseases; Industry; Prognosis
PubMed: 38918653
DOI: 10.31557/APJCP.2024.25.6.1929 -
JMIR Formative Research Jun 2024Accelerated digitalization in the health sector requires the development of appropriate evaluation methods to ensure that digital health technologies (DHTs) are safe and...
BACKGROUND
Accelerated digitalization in the health sector requires the development of appropriate evaluation methods to ensure that digital health technologies (DHTs) are safe and effective. Software as a medical device (SaMD) is a commonly used DHT by clinicians to provide care to patients. Traditional research methods for evaluating health care products, such as randomized clinical trials, may not be suitable for DHTs, such as SaMD. However, evidence to show their safety and efficacy is needed by regulators before they can be used in practice. Clinical simulation can be used by researchers to test SaMD in an agile and low-cost way; yet, there is limited research on criteria to assess the robustness of simulations and, subsequently, their relevance for a regulatory decision.
OBJECTIVE
The objective of this study was to gain consensus on the criteria that should be used to assess clinical simulation from a regulatory perspective when it is used to generate evidence for SaMD.
METHODS
An eDelphi study approach was chosen to develop a set of criteria to assess clinical simulation when used to evaluate SaMD. Participants were recruited through purposive and snowball sampling based on their experience and knowledge in relevant sectors. They were guided through an initial scoping questionnaire with key themes identified from the literature to obtain a comprehensive list of criteria. Participants voted upon these criteria in 2 Delphi rounds, with criteria being excluded if consensus was not met. Participants were invited to add qualitative comments during rounds and qualitative analysis was performed on the comments gathered during the first round. Consensus was predefined by 2 criteria: if <10% of the panelists deemed the criteria as "not important" or "not important at all" and >60% "important" or "very important."
RESULTS
In total, 33 international experts in the digital health field, including academics, regulators, policy makers, and industry representatives, completed both Delphi rounds, and 43 criteria gained consensus from the participants. The research team grouped these criteria into 7 domains-background and context, overall study design, study population, delivery of the simulation, fidelity, software and artificial intelligence, and study analysis. These 7 domains were formulated into the simulation for regulation of SaMD framework. There were key areas of concern identified by participants regarding the framework criteria, such as the importance of how simulation fidelity is achieved and reported and the avoidance of bias throughout all stages.
CONCLUSIONS
This study proposes the simulation for regulation of SaMD framework, developed through an eDelphi consensus process, to evaluate clinical simulation when used to assess SaMD. Future research should prioritize the development of safe and effective SaMD, while implementing and refining the framework criteria to adapt to new challenges.
PubMed: 38917454
DOI: 10.2196/56241 -
PloS One 2024Access to brushes allows for natural scratching behaviors in cattle, especially in confined indoor settings. Cattle are motivated to use brushes, but brush use varies...
Access to brushes allows for natural scratching behaviors in cattle, especially in confined indoor settings. Cattle are motivated to use brushes, but brush use varies with multiple factors including social hierarchy and health. Brush use might serve an indicator of cow health or welfare, but practical application of these measures requires accurate and automated monitoring tools. This study describes a machine learning approach to monitor brush use by dairy cattle. We aimed to capture the daily brush use by integrating data on the rotation of a mechanical brush with data on cow identify derived from either 1) low-frequency radio frequency identification or 2) a computer vision system using fiducial markers. We found that the computer vision system outperformed the RFID system in accuracy, and that the machine learning algorithms enhanced the precision of the brush use estimates. This study presents the first description of a fiducial marker-based computer vision system for monitoring individual cattle behavior in a group setting; this approach could be applied to develop automated measures of other behaviors with the potential to better assess welfare and improve the care for farm animals.
Topics: Animals; Cattle; Behavior, Animal; Machine Learning; Dairying; Radio Frequency Identification Device; Female; Algorithms; Animal Welfare
PubMed: 38917231
DOI: 10.1371/journal.pone.0305671 -
PloS One 2024The underwater laser polarization detection technology integrates the polarization characteristics of light into the detection and identification of underwater targets....
The underwater laser polarization detection technology integrates the polarization characteristics of light into the detection and identification of underwater targets. Addressing the challenge of poor accuracy in identifying targets in strong underwater scattering environments, this article proposes an overall scheme for a laser polarization underwater detection device that suppresses scatter using polarized pulse signals. By overcoming key technological barriers in the design of polarization-preserving optical detection systems and utilizing the method of differential amplitude to measure polarization, a laser polarization underwater detection device was developed and underwater polarization detection experiments were conducted, achieving precise detection of underwater targets. The results indicate that the underwater detection device we designed has a root mean square error of less than 5.7% to detect the polarization of the target, demonstrating the accuracy and precision of the underwater detection device.
Topics: Lasers; Scattering, Radiation; Water; Light
PubMed: 38917184
DOI: 10.1371/journal.pone.0305929 -
PloS One 2024This study developed and validated a surgical instrument motion measurement system for skill evaluation during practical laparoscopic surgery training. Owing to the...
This study developed and validated a surgical instrument motion measurement system for skill evaluation during practical laparoscopic surgery training. Owing to the various advantages of laparoscopic surgery including minimal invasiveness, this technique has been widely used. However, expert surgeons have insufficient time for providing training to beginners due to the shortage of surgeons and limited working hours. Skill transfer efficiency has to be improved for which there is an urgent need to develop objective surgical skill evaluation methods. Therefore, a simple motion capture-based surgical instrument motion measurement system that could be easily installed in an operating room for skill assessment during practical surgical training was developed. The tip positions and orientations of the instruments were calculated based on the marker positions attached to the root of the instrument. Because the patterns of these markers are individual, this system can track multiple instruments simultaneously and detect exchanges. However due to the many obstacles in the operating room, the measurement data included noise and outliers. In this study, the effect of this decrease in measurement accuracy on feature calculation was determined. Accuracy verification experiments were conducted during wet-lab training to demonstrate the capability of this system to measure the motion of surgical instruments with practical accuracy. A surgical training experiment on a cadaver was conducted, and the motions of six surgical instruments were measured in 36 cases of laparoscopic radical nephrectomy. Outlier removal and smoothing methods were also developed and applied to remove the noise and outliers in the obtained data. The questionnaire survey conducted during the experiment confirmed that the measurement system did not interfere with the surgical operation. Thus, the proposed system was capable of making reliable measurements with minimal impact on surgery. The system will facilitate surgical education by enabling the evaluation of skill transfer of surgical skills.
Topics: Laparoscopy; Humans; Clinical Competence; Surgical Instruments; Motion; Cadaver; Nephrectomy
PubMed: 38917181
DOI: 10.1371/journal.pone.0305693 -
PloS One 2024To analyze needs and requirements of Pediatric Physical Therapists (PPTs), parents, children and adolescents with and without developmental disabilities in the future...
AIMS
To analyze needs and requirements of Pediatric Physical Therapists (PPTs), parents, children and adolescents with and without developmental disabilities in the future use of an activity monitor prototype (AM-p) in everyday clinical practice.
METHODS
Qualitative exploratory study with a thematic analysis approach, based on Braun and Clarke's six steps. Codes derived from the analysis and central themes were collated, based on Fleuren et al.'s groupings of determinants.
RESULTS
We interviewed 25 PPTs, 12 parents, and 12 children and adolescents. Within four groupings of determinants, we found nine themes: 1) development of information materials; 2) application: output visualization and ease of use; 3) design; 4) relevance and acceptance; 5) shared decision-making; 6) compatibility in daily living; 7) finances, 8) time, and 9) legislation and regulations.
CONCLUSIONS
End-users have similar basic needs, with individual fine-tuning to be addressed during further development of the AM-p. A child-friendly design, information material, and an easy-to-use application to read and interpret results, need to be developed. Efficient training for PPTs is important for the use of the AM-p and analysis of results. Communication between PPTs and children as well as parents enhances shared decision-making. We recommend involving diverse end-users to enable maximum customization of the AM-p.
Topics: Humans; Child; Adolescent; Male; Female; Qualitative Research; Exercise; Physical Therapy Modalities; Adult; Parents; Physical Therapists; Developmental Disabilities
PubMed: 38917177
DOI: 10.1371/journal.pone.0305968 -
PloS One 2024To date, several types of airway stents are available to treat central airway obstructions. However, the ideal stent that can overcome anatomical, mechanical and...
To date, several types of airway stents are available to treat central airway obstructions. However, the ideal stent that can overcome anatomical, mechanical and microbiological issues is still awaited. In addition, therapeutic effect and self-elimination of these stents are desirable properties, which pose an additional challenge for development and manufacturing. We aimed to create a prototype bioresorbable tracheal stent with acceptable clinical tolerance, fit and biocompatibility, that could be tested in a rabbit model and in the future be further optimized to enable drug-elution and ensure local therapeutic effect. Twenty-one New Zealand White Rabbits received five different types of bioresorbable tracheal stents, 3D-printed from poly(D,L-lactide-co-ε-caprolactone) metacrylates. Various configurations were tested for their functionality and improved until the best performing prototype could undergo detailed in vivo assessment, regarding clinical tolerance, migration and biocompatibility. Previously tested types of 3D printed stents in our preliminary study required improvement due to several problems, mainly related to breakage, unreliable stability and/or migration within the trachea. Abandoned or refined pre-prototypes were not analyzed in a comparative way. The final best performing prototype stent (GSP2 (Group Stent Prototype 2), n = 8) allowed a transoral application mode and showed good clinical tolerance, minimal migration and acceptable biocompatibility. The good performance of stent type GSP2 was attributed to the helix-shaped surface structure, which was therefore regarded as a key-feature. This prototype stent offers the possibility for further research in a large animal model to confirm the promising data and assess other properties such as bioresorption.
Topics: Animals; Rabbits; Printing, Three-Dimensional; Stents; Trachea; Absorbable Implants; Materials Testing; Biocompatible Materials; Prosthesis Design; Polyesters
PubMed: 38917158
DOI: 10.1371/journal.pone.0300847