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Dosimetry comparison of aapm tg-43 and monte carlo calculations in 192ir hdr brachytherapy for patients with tongue cancer using egs_brachy source code
No full textHigh-dose-rate (HDR) brachytherapy employing Iridium-192 is a recognized
technique for the treatment of tongue cancer, providing the benefit of delivering highly
conformal doses while protecting adjacent critical structures. The American Association of
Physicists in Medicine Task Group 43 (AAPM TG 43) formalism serves as the prevailing
clinical standard for dose calculations; however, it operates under the assumption of a
uniform water environment, thereby overlooking patient-specific anatomical differences.
This study examines the variances between the AAPM TG 43 formalism and Monte Carlo
(MC) simulations utilizing the egs_brachy application, which facilitates more precise patientspecific
dose calculations by incorporating heterogeneities.
CT datasets from three patients with tongue cancer who underwent HDR
brachytherapy were examined. Treatment plans based on AAPM TG-43 were created using
the Oncentra Brachy Treatment Planning System (TPS). Subsequently, these plans were
transferred into the egs_brachy MC simulation framework through the eb_gui interface,
enabling voxel-based modeling of patient anatomy and the simulation of dose distributions
with detailed tissue assignment schemes. Dose Volume Histograms (DVHs) and statistical
metrics such as D90, D100 for the Planning Target Volume (PTV), and D0.1cc, D1.0cc, and D2.0cc
for organs at risk (OARs) were evaluated across both methodologies. The results indicated
significant differences in the dosimetric parameters between the AAPM TG-43 and MC
simulations. The AAPM TG-43 approach typically overestimated doses to the GTV while
underestimating doses to specific OARs, highlighting its limitations in addressing patientspecific
anatomical complexities. These findings emphasize the potential of MC simulations using egs_brachy as a more precise and reliable alternative for dose calculation in HDR
brachytherapy, especially in anatomically intricate regions such as the oral cavit
Investigation of free breathing technique implication towards cardiac structure dose in left breast radiotherapy:retrospective study
No full textThis study aimed to comprehensively evaluate the dosimetric parameters of cardiac
structures, assess volumetric-dosimetric correlations, and investigate the relationship
between heart dose and LAD specific dosimetry in left breast radiotherapy plans. The
objective was to ascertain adherence to recommended tolerance levels and identify critical
parameters for cardiac sparing. A retrospective analysis was conducted on 35 left breast
cancer patients treated with 3D-CRT at Hospital Pakar Universiti Sains Malaysia (HPUSM)
from January to December 2024, receiving a prescribed dose of 40 Gy in 15 fractions. No
data beyond December 2024 was included in this study, and the research period did not
extend beyond July 2025. Ethical clearance was secured, and purposive sampling was
employed. CT simulation was performed under free breathing conditions. Organs at risk
(OARs), including the heart, underwent auto-contouring, while the LAD was manually
delineated by a medical physicist due to its complicated structure visualized in the CT
images. Dosimetric parameters were assessed against RTOG 0617 and DEGRO tolerance
guidelines. Spearman's rho correlation analysis was utilized to determine relationships
between heart/LAD volumes and their respective doses, as well as between heart mean dose
and LAD-specific doses, following preliminary normality testing. The analysis revealed no
statistically significant correlation between heart volume and heart mean dose (r =0.018, p=0.917), nor between LAD volume and its dosimetric parameters (LAD Dmean: r
=−0.077, p=0.659; LAD V40: r =0.162, p=0.353). A moderate, statistically significant
positive correlation was identified between heart mean dose and mean LAD dose (r
=0.442, p=0.008). Conversely, the correlation between heart mean dose and LAD V40 (%)
was not statistically significant (r =0.240, p=0.165). Volumetric parameters of the heart and
LAD do not reliably predict radiation dose to these structures. While a correlation exists
between heart mean dose and mean LAD dose, global heart dose metrics are insufficient to
fully capture critical high-dose regions within the LAD. Consequently, for effective cardiac
sparing in left breast radiotherapy, future planning necessitates meticulous monitoring
of both the overall heart mean dose and, crucially, LAD-specific parameters, particularly
LAD V40 (%), to ensure comprehensive cardiac protection and mitigate long-term
cardiotoxicity. Future investigations should involve larger cohorts to confirm these findings
and explore the clinical impact of LAD V40 exceedance
Anti-asthmatic and airway smooth muscle relaxation effects of polysaccharides from lignosus rhinocerotis in animal models ROM Lignosus rhinocerotis IN ANIMAL MODELS
No full textAsthma is a chronic airway disease which is associated with several
characteristics including bronchoconstriction, airway vasodilation, oedema, sensory
nerve activation, and hypersensitivity. Systemic corticosteroids are crucial for
managing moderate-to-severe asthma but are associated with various adverse effects
with long-term use. This has driven researchers to explore safer complementary and
alternative anti-asthmatic interventions to mitigate these exaggerated immune
responses. Mushroom polysaccharides (MP) have been reported to contain β-glucan
compounds and polysaccharide-protein complexes, which are known to exhibit several
bioactivities, including anti-inflammatory, immunomodulatory, antitumor, and
antioxidant properties, as demonstrated in numerous in vivo and in vitro studies.
However, the potential of inhaled Lignosus rhinocerotis polysaccharide (LRP) to
ameliorate asthma pathophysiology remains undetermined, and current research on its
bioactive properties is limited. Therefore, this study aimed to (i) isolate and determine
the polysaccharide composition of LR mushrooms, (ii) determine LRP inhalation
delivery, (iii) establish a BALB/c mouse model of OVA-challenged allergic asthma
and determine the effect of LRP on asthma pathophysiology, and (iv) determine the
effect of LRP on airway receptor contractility in guinea pig tracheal (GPT) rings. The
LRP DEAE-cellulose and Sephadex G-100 column elution exhibited a single
symmetrical peak fractionated polysaccharide fraction. The megazyme β-glucan assay
revealed that the percentages of α- and β-glucans in LRP were 21.52% (±0.53) and 21.07% ± (2.19), respectively. HPLC analysis revealed that LRP was a typical
heteropolysaccharide composed of mannose, ribose, rhamnose, glucose, galactose,
xylose, and arabinose. LRP spray drying was shown to produce unstable LRP powders
due to its volatility and hygroscopic nature. Nebulization of the LRP solution-produced
inhalable aerosols for lung delivery, the in vitro aerosol deposition using NGI
demonstrated fine particle fraction (FPF) of 62.84, mean median aerodynamic
distribution (MMAD) of 4.16, and geometric standard deviation (GSD) of 1.83. LRP
nebulization treatment (4, 8, and 40 mg/ml) in an OVA-challenged mouse model of
asthma significantly inhibited airway inflammation, and Cox-2, iNOS, and ADAM33
lung inflammatory gene expression (p<0.05), with 8 and 40 mg/ml treatment groups
expressing the most significant effect. Furthermore, LRP demonstrated an airway
relaxation effect independent of beta receptors, potentially through muscarinic and
histamine receptor antagonism in carbachol-and histamine-pre-contracted GPT rings
(p<0.05). These findings suggest the therapeutic potential of LR mushroom
polysaccharides as complementary alternatives for the management of allergic asthm
Evaluation of bacterial colonization on titanium dental implant surfaces following different instrumentation techniques: a comparative study
No full textThe use of various hygiene tools for implant maintenance affects surface configurations, which in turn affects bacterial adhesion on titanium implant surfaces, which can lead to peri-implant diseases. This study aimed to compare the surface topographies and Streptococcus sanguinis colonization on titanium implant fixture surfaces after polishing methods with Er, Cr: YSGG laser, airflow, and titanium brush group with control/untreated group using Scanning Electron Microscope (SEM) observation and Colony Forming Unit (CFU) counts. Twenty MegaGen titanium implant fixtures were randomly distributed into four groups. Five fixtures were randomly selected for the control/untreated (C) group while the other three groups were treated with Er, Cr: YSGG laser, airflow, and titanium brush. One fixture from each group was observed under SEM for surface topographies evaluation. All other samples were cultured with Streptococcus sanguinis for bacterial colonization and adhesion evaluation. One sample for each group was selected for SEM observation while the other samples were prepared for CFU counting. From the SEM analysis, the surface topography produced by the titanium brush showed a smooth surface followed by airflow with fewer surface irregularities, and the laser group showed a haphazard structure as compared to the control group. Similarly, for bacterial colonization, the titanium brush had the least bacterial cell growth, sparsely present on the surface same as the control group followed by the airflow group showed the multilayer chains of colonies, and the laser group showed the clusters of colonies. However, for the CFU
result, statistical analysis revealed a significant value (p<0.05) among all four groups. Titanium brush was concluded as the least invasive and most effective instrumentation tool for implant fixture surface topographies and bacterial growth evaluated under SEM. However, from CFU counts, the airflow instrumentation was found to be the one having the least bacterial counts compared to other group
Sociodemographic, dietary pattern, serum biomarkers (insulin-like growth factor 1 (igf-1) and insulin-like growth factor binding protein 3 (igfbp-3)) and genetic polymorphisms in breast cancer among palestinian women: a case control study
Full text linkBreast cancer (BC) remains a global public health challenge. This case-control study explores the relationships between serum insulin-like growth factor binding protein 3 (IGFBP-3), insulin-like growth factor 1 (IGF-1), genetic polymorphisms, dietary patterns, and BC risk in Palestinian women. The study involved 112 newly diagnosed BC confirmed by histopathology and 222 age-matched, cancer-free controls. Data collection included face-to-face interviews, biochemical, genetic, and immunohistochemical analyses, and bioinformatics. Tumour tissue samples from BC cases were analysed for ER, PR, and HER-2 status. SPSS program version 28 was used for all data analysis. Multivariate analysis revealed that elevated serum IGF-1 levels were associated with increased BC risk (OR=1.013; 95%CI 1.007, 1.019), as well as ER(+)/PR(+) status (rs= 0.232, p ≤ 0.001) and advanced disease stages (III and IV) (rs= 0.191, p ≤ 0.001; rs= 0.119, p = 0.029) respectively. Higher BC odds were linked to never being pregnant (OR=2.122; 95%CI 1.022, 4.408), first delivery at ≤18 years (OR=6.033; 95%CI 2.217, 16.413), and low-intensity exercise (OR=9.609; 95%CI 1.009, 91.471). Conversely, women aged 35–40 years had a reduced BC risk compared to those <35 years (OR=0.427; 95%CI 0.188, 0.971). The IGFBP-3 A-202C polymorphism showed significant associations with BC risk. The homozygous CC allele was more frequent in cases (70.5%) compared to controls (20.7%) and linked to elevated IGFBP-3 (rs = 0.164; p = 0.003) and IGF-1 levels (rs = 0.175; p ≤ 0.001), and an increased risk of BC (OR=16.237; 95%CI 7.904, 33.356, p ≤ 0.001). Moreover, the IGFBP-3 A-202C genotype was significantly associated with PR status and double positive hormone receptor ER/PR (p = 0.020). Furthermore, bioinformatics analysis identified IGF-1 variants (rs1520220, rs6214, rs7136446, rs6220) significantly associated with breast carcinoma and malignant neoplasm of the breast (p-value = 6.29E−0.6 and 2.84E−0.6) respectively. Additionally, the dietary analysis revealed that eight of the 14 food groups studied were linked to a decreased risk of BC, including fresh fruits and their juices (OR= 0.966; 95%CI 0.947, 0.985), meat products (OR= 0.963; 95%CI 0.934, 0.993), grains (OR=0.944; 95%CI 0.912, 0.977), low-fat dairy (OR=0.970; 95%CI 0.945, 0.995), nuts (OR=0.835; 95%CI 0.745, 0.936), snacks and sweets (OR=0.967, 95%CI 0.937, 0.998), and soups and sauces (OR=0.945; 95%CI 0.911, 0.979), were associated with a reduction in BC risk, while eggs were associated with increased risk (OR=1.125; 95%CI 1.019,1.243) with p-values < 0.05. Drinks and beverages was positively correlated with IGF-1 levels (rp = 0.121, p = 0.027). These findings underscore the importance of IGF-1 and IGFBP-3 as potential biomarkers for BC risk. Integrating genetic, biochemical, dietary, and lifestyle factors provides novel insights for personalized prevention and treatment strategies, particularly in resource-limited settings such as the Gaza Stri
Alternative method to develop new strategy in ordinal regression: a case study in dental
No full textClinical data usually contain numerous features with a small sample size, resulting in higher dimensionality and poor accuracy. This reduces the performance of classifier systems in high-dimensional data sets because irrelevant features contribute to poor classification accuracy and add extra difficulties in finding potentially useful knowledge. The main objective is to develop an alternative model for ordinal regression through statistical methodology building. The methodology includes a computational study design and statistical techniques customised for dental science modelling. A combination of ordinal regression and bootstrap techniques in the developing an alternative model is the main key to the research focal point. Two case studies, tooth wear severity and tooth sensitivity, were used to test this technique, demonstrating its relevance to real-world dental data. All the fundamental programming was performed using R software. The results show that the alternative approach, especially with more bootstrap replications, offers improved model fitting and precision compared to traditional ordinal regression. This suggests its usefulness in improving the accuracy of health science research, especially in situations with small sample sizes. This study strengthens statistical methods in dental sciences by introducing a more robust alternative to ordinal regression, enabling researchers to obtain more accurate and reliable results even with limited datasets
The establishment of typical dose and assessment of scanning parameters influencing radiation dose in cardiac computed tomography (CT) imaging
No full textCardiac computed tomography (CT) is widely used for detecting coronary artery disease but involves relatively high radiation doses, necessitating optimisation. This study aimed to determine typical dose levels and assess scanning parameter influencing dose variation in cardiac CT at HPUSM. A total of 200 cases were retrospectively reviewed from Siemens SOMATOM Definition AS+ and Philips Incisive CT scanners. Demographic and technical data, including mAs, exposure time, scan length, CTDI vol, and DLP, were extracted from PACS and VIARAD5. Microsoft Excel 2021 was used to analyse the relationship between scan parameters and dose. CorCTAAdapt (Siemens) showed the lowest dose, while CTA Coronary (Philips) had the highest. Positive correlations were found between mAs, exposure time, and scan length with CTDIvol and DLP. The 50th percentile defined the typical dose; the 75th established local diagnostic reference levels (LDRLs). Typical doses were 17.39 mGy/233.00 mGy·cm (CorCTA), 16.87 mGy/168.50 mGy·cm (CorCTAAdapt), and 48.97 mGy/861.90 mGy·cm (CTA Coronary). This study established typical dose values and identified key scanning parameters that influence dose in cardiac CT imaging. The findings offer important local reference data for dose optimisation and support the development of safer, standardised imaging protocols at HPUSM
Impact of glyphosate (herbicide) and chlorpyrifos (insecticide) contamination on necrophagous fly lifecycle on pork
No full textForensic entomology is crucial in criminal investigations, but insect development can be influenced by toxic substances, affecting post-mortem interval (PMI) estimations. This study examines the impact of glyphosate (herbicide) and chlorpyrifos (insecticide) contamination on necrophagous fly lifecycles on decomposing pork meat. Experiments were conducted using control, glyphosate-treated, and chlorpyrifos-treated samples over 14 days in both rainy and non-rainy seasons. Four necrophagous fly species—Chrysomya megacephala, Chrysomya rufifacies, Lucilia sp., and Sarcophaga sp.—were observed in control and glyphosate-treated samples, with no significant differences in lifecycle duration, morphology, or species composition. However, chlorpyrifos contamination drastically reduced oviposition, causing larval mortality at the first instar and slowing decomposition. Glyphosate did not affect decomposition or insect activity, whereas chlorpyrifos delayed decay due to reduced insect colonisation, potentially impacting forensic PMI estimations. Attempts to detect pesticide residues in larvae using gas chromatography-flame ionisation detection (GC-FID) were inconclusive, as the recovery study failed, possibly due to extraction inefficiencies or the instrument’s limited sensitivity to these compounds. These findings highlight the need for improved toxicological methods for pesticide detection in forensic entomolog
Detection of microplastics in bottled drinking water
No full textas a significant concern, particularly regarding its potential implications for product safety and consumer health. This study aimed to evaluate the leaching of MPs under different conditions, including temperature variations at room temperature (25 ± 2°C) and peak temperature (60 ± 2°C), mechanical stress at two shaking speeds (30 RPM and 60 RPM), and repeated usage of drinking bottled water. Additionally, the study characterized the morphology of the leached MPs. Results revealed that peak temperatures and increased mechanical stress significantly enhanced MPs release, with peak leaching observed at 60°C and 60 RPM. Repeated use further amplified the release, indicating that thermal and mechanical degradation play critical roles in the fragmentation of MP particles. The most commonly observed MP shapes were pellets, fibers, and filaments, with transparent MPs dominating across all tests, reflecting the material of the bottles. This study highlighted the awareness to the consumer on the critical impact of thermal, mechanical stress and repeated use of drinking bottled water through temperature test at two different temperatures (25 ± 2 and 60 ± 2°C), shaking test at 30 RPM and 60 RPM, and the reusability test, on the release of MPs from single-use bottled drinking water
Removal of lead, cadmium and nickel ions from aqueous solution using rambutan and date seeds as adsorbents
No full textHeavy metal contamination in aquatic environments, particularly by lead (Pb), cadmium (Cd), and nickel (Ni), poses significant environmental and health risks due to their toxicity and persistence. This study evaluated the potential of rambutan (Nephelium lappaceum) and date (Phoenix dactylifera) seeds as biosorbents for the removal of these metals from aqueous solutions. Adsorption experiments were conducted under varying conditions of metal ion concentration, adsorbent dosage, contact time, and temperature. The concentrations of Pb, Cd, and Ni ions were measured using Flame Atomic Absorption Spectroscopy (FAAS), while biosorbents were characterised pre- and post-treatment using Fourier Transform Infrared Spectroscopy (FTIR) to identify functional groups involved in the adsorption process. The optimal parameters for Pb, Cd, and Ni removal using rambutan seeds were an initial concentration of 1 ppm, an adsorbent dosage of 0.5 g, a contact duration of 40 minutes, and a temperature of 30°C, achieving removal efficiencies of 97.2%, 90.3%, and 16.1%, respectively. For date seeds, the same conditions yielded removal efficiencies of 81.9% for Cd and 48.5% for Ni, while 96.4% for Pb for 60 minutes of contact time. The results demonstrated that both biosorbents are highly effective for the removal of Pb and Cd, but rambutan slightly higher in average compared to date and less efficient for Ni. This study highlighted the potential of rambutan and date seeds as cost-effective and eco-friendly alternatives for heavy metal remediation,contributing to sustainable water treatment solutions and advancing the use of agricultural waste for environmental remediation