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1.
Biomed Phys Eng Express ; 10(5)2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38906125

RESUMEN

Purpose/Objective. Small-field measurement poses challenges. Although many high-resolution detectors are commercially available, the EPID for small-field dosimetry remains underexplored. This study aimed to evaluate the performance of EPID for small-field measurements and to derive tailored correction factors for precise small-field dosimetry verification.Material/Methods. Six high-resolution radiation detectors, including W2 and W1 plastic scintillators, Edge-detector, microSilicon, microDiamond and EPID were utilized. The output factors, depth doses and profiles, were measured for various beam energies (6 MV-FF, 6 MV-FFF, 10 MV-FF, and 10 MV-FFF) and field sizes (10 × 10 cm2, 5 × 5 cm2, 4 × 4 cm2, 3 × 3 cm2, 2 × 2 cm2, 1 × 1 cm2, 0.5 × 0.5 cm2) using a Varian Truebeam linear accelerator. During measurements, acrylic plates of appropriate depth were placed on the EPID, while a 3D water tank was used with five-point detectors. EPID measured data were compared with W2 plastic scintillator and measurements from other high-resolution detectors. The analysis included percentage deviations in output factors, differences in percentage for PDD and for the profiles, FWHM, maximum difference in the flat region, penumbra, and 1D gamma were analyzed. The output factor and depth dose ratios were fitted using exponential functions and fractional polynomial fitting in STATA 16.2, with W2 scintillator as reference, and corresponding formulae were obtained. The established correction factors were validated using two Truebeam machines.Results. When comparing EPID and W2-PSD across all field-sizes and energies, the deviation for output factors ranged from 1% to 15%. Depth doses, the percentage difference beyond dmax ranged from 1% to 19%. For profiles, maximum of 4% was observed in the 100%-80% region. The correction factor formulae were validated with two independent EPIDs and closely matched within 3%.Conclusion. EPID can effectively serve as small-field dosimetry verification tool with appropriate correction factors.


Asunto(s)
Aceleradores de Partículas , Radiometría , Radiometría/instrumentación , Radiometría/métodos , Aceleradores de Partículas/instrumentación , Diseño de Equipo , Fantasmas de Imagen , Calibración , Humanos , Conteo por Cintilación/instrumentación , Conteo por Cintilación/métodos , Reproducibilidad de los Resultados
2.
Cureus ; 15(9): e44764, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37809194

RESUMEN

Lattice radiation therapy (LRT) is an advanced treatment approach specifically designed for massive tumors. It aims to deliver high-dose regions within tumors while ensuring the safety of the surrounding dose-limiting organs at risk (OAR). This case report introduces two unique clinical cases: a 63-year-old male diagnosed with a massive non-small cell lung cancer (NSCLC) tumor and a 61-year-old male with an inoperable recurrent left-sided adrenal mass intricately surrounded by dose-limiting bowel structures. Both patients underwent LRT to enhance tumor control and maintain less toxicity. Notably, both patients displayed a significant tumor volume reduction accompanied by minimal adverse effects during the 12-month follow-up period. While these initial results suggest that LRT may be effective and safe for treating large tumors, further investigation through exhaustive research and multicenter trials is necessary to fully understand and determine the specifics of lattice radiation therapy techniques.

3.
J Med Phys ; 44(1): 16-20, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30983766

RESUMEN

PURPOSE: PerFRACTION™ is a three-dimensional (3D) in vivo electronic portal imaging device-based dosimetry software. To validate the software, three phantoms with different inserts (2D array, ionization chamber, and inhomogeneity materials) were constructed to evaluate point dose and fluence map. MATERIALS AND METHODS: Phantoms underwent independent computed tomography simulation for planning and received repetitive fractions of volumetric modulated arc therapy, simulating prostate treatment. Fluence and absolute point dose measurements, PerFRACTION™ reconstructed doses, and the dose predictions of the planning system were compared. RESULTS: There was concordance between ionization chamber and PerFRACTION™ 3D absolute point dose measurements. Close agreement was also obtained between X- and Y-axis dose profiles with PerFRACTION™ calculated doses, MapCHECK measured doses, and planning system predicted doses. Setup shifts significantly influenced 2D gamma passing rates in PerFRACTION™ software. CONCLUSIONS: PerFRACTION™ appears reliable and valid under experimental conditions in air and with phantoms.

4.
Haemophilia ; 22(4): 549-55, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27030081

RESUMEN

INTRODUCTION: An increased prevalence of hypertension has been reported in patients with haemophilia compared to the age-matched general population, although the causes were unclear. To date, there has been limited data implicating haemophilia-specific risk factors such as renal bleeding. AIM: This two-centre prospective cohort study aimed to assess the prevalence of gross/microscopic haematuria, and the associations between haematuria, blood pressure and renal function. METHODS: Of 135 adult males, with mild to severe haemophilia followed by the British Columbia and University of California San Diego Hemophilia Treatment Centers were included. Screening urinalysis and microscopy were performed during all routine visits. Haematuria was defined as history of gross haematuria or >3 red blood cells per high-power field on microscopy in the absence of urinary tract infections. Logistic regressions were used to examine the significance of haematuria and other potential hypertension risk factors. RESULTS: The prevalence of hypertension was 44%, of whom 31% achieved adequate blood pressure control. Despite the high prevalence of haematuria (34%), renal dysfunction was rare. On univariate analysis, age, diabetes, dyslipidemia and obesity were associated with hypertension. On multivariate analysis, only age remains as a significant predictor of hypertension. Haematuria was not associated with hypertension, renal insufficiency or haemophilia severity. CONCLUSION: In this cohort, hypertension and haematuria were prevalent while renal disease was rare. Haematuria was not associated with a diagnosis of hypertension or renal dysfunction. Larger prospective studies are needed to elucidate the mechanisms for increased prevalence of hypertension in haemophilia.


Asunto(s)
Hematuria/diagnóstico , Hemofilia A/complicaciones , Adulto , Anciano , Presión Sanguínea/fisiología , Estudios de Cohortes , Tasa de Filtración Glomerular , Hematuria/complicaciones , Humanos , Hipertensión/epidemiología , Hipertensión/etiología , Enfermedades Renales/epidemiología , Enfermedades Renales/etiología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Obesidad/complicaciones , Prevalencia , Estudios Prospectivos , Factores de Riesgo , Urinálisis
5.
New Microbes New Infect ; 7: 89-93, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26442150

RESUMEN

Biochemical tests have been previously developed to identify carbapenemase-producing Enterobacteriaceae, Pseudomonas spp. (Carba NP test) and Acinetobacter spp. (CarbAcineto NP test). We evaluated a modified Carba NP test to detect carbapenemase production in Enterobacteriaceae, Pseudomonas and Acinetobacter species using a single protocol with rapid results and found good reliability and speed.

6.
Vet Rec Open ; 2(1): e000054, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26392885

RESUMEN

INTRODUCTION: Bluetongue (BT) is a non-contagious infectious disease of ruminants. The disease agent bluetongue virus (BTV) is classified in the Reoviridae family Orbivirus. AIMS AND OBJECTIVES: The aim of this study was to determine serum malondialdehyde (MDA), total antioxidative stres (TAS), total sialic acid (TSA), ceruloplasmin, triglyceride, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), cholesterol, creatinine, albumin, and total protein levels in sheep with and without bluetongue (BT). MATERIALS AND METHODS: The study included 13 Sakiz crossbreed sheep, aged 1-4 years and usually in the last stage of pregnancy, as the BT group and a control group consisting of 10 healthy sheep. All sheep were clinically examined before collecting blood samples. Serum ALT, AST, cholesterol, triglyceride, albumin, GGT, total protein, creatinine and TAS levels were measured using commercially available kits as per manufacturer's recommendations using a Biochemistry Auto Analyzer (Sinnowa D280, China). Serum lipid peroxidation was estimated through a previously described method in which MDA reacts with thiobarbituric acid (TBA) to form a coloured complex at a maximum absorbance of 535 nm. The TSA value was measured at 549 nm using the method described by Warren (1959): sialic acid was oxidised to formyl-pyruvic acid, which reacts with TBA to form a pink product. The ceruloplasmin concentration was measured according to Sunderman and Nomoto (1970): ceruloplasmin and p-phenylenediamine formed a coloured oxidation product that was proportional to the concentration of serum ceruloplasmin. Real time RT-PCR and conventional RT-PCR were performed as described by Shaw and others (2007). RESULTS: Biochemistry analysis of serum showed that in the BT group, TSA, MDA, triglyceride and ALT and AST were higher and that ceruloplasmin and TAS were lower than in the control group. Serum albumin, cholesterol, creatinine, total protein and GGT did not differ significantly between the two groups. CONCLUSIONS: Serum triglyceride, ceruloplasmin, TSA, MDA and TAS concentrations may prove beneficial to the diagnosis, prognosis and biochemical analysis of BT.

7.
Haemophilia ; 20(6): 763-70, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24893625

RESUMEN

In haemophilia, coronary heart disease (CHD) occurs at a similar frequency as in the general population, but the contributing risk factors in haemophilia are incompletely understood. To investigate risk factors and 10-year CHD risk in a single centre cohort of patients with haemophilia (PWH) ≥20 years old (n = 89). We retrospectively applied the modified Framingham National Cholesterol Education Program/Adult Treatment Panel (NCEP/ATP) III risk prediction equation. Three risk levels were defined: <10% (low), 10-20% (intermediate) and >20% (high). Results were compared to the National Health and Nutrition Examination Survey (NHANES). Mean age in both cohorts was similar. Compared to NHANES, systolic blood pressures were significantly higher in PWH, but current smoking and cholesterol were lower. CHD risk differed significantly between PWH and NHANES (P = 0.005) with a higher proportion of PWH classified at low risk (77.5% vs. 61.0%). The proportion of low risk patients was also significantly higher for severe haemophilia patients compared to non-severe haemophilia patients (88.6% vs. 66.7%, P = 0.02). Among PWH, and compared to PWH who were hepatitis C (HepC) negative, HepC positive patients had significantly lower cholesterol, LDL and triglycerides. The CHD risk of HepC positive patients differed significantly from NHANES (P = 0.03) with a lower proportion of HepC positives being classified as high risk (5.7% vs. 17.3%). Favourable CHD risk classification in PWH may be influenced by low cholesterol associated with HepC infection. Estimates of CHD risk in PWH by composite scoring may not be accurate and will require studies correlating risk factors with incident CHD.


Asunto(s)
Enfermedad Coronaria/epidemiología , Enfermedad Coronaria/etiología , Hemofilia A/complicaciones , Hemofilia B/complicaciones , Adolescente , Adulto , California/epidemiología , Comorbilidad , Hemofilia A/diagnóstico , Hemofilia B/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Estados Unidos/epidemiología , Adulto Joven
8.
Injury ; 2012 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-22867690

RESUMEN

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

9.
Turk J Pediatr ; 52(1): 58-67, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20402068

RESUMEN

We report the somatic growth characteristics of 60 infants who underwent corrective surgery for congenital heart disease. Patients were assigned to the following groups: Group 1, cyanosis with pulmonary hypertension (PH); Group 2, cyanosis without PH; Group 3, large left-to-right shunt and PH; and Group 4, left-to-right shunt or obstructive heart lesion and no PH. Weight, length, and head circumference measurements and z scores were obtained before the operation, at 45 days, and 3, 6, and 12 months after the operation. Details about dietary intake, socioeconomic status at presentation, length of stay in the intensive care unit, hospitalization period, and perioperative events were noted. The endpoint was reaching a z score > -1 for all anthropometric measurements. At presentation, 51 patients (85%) had malnutrition. The family income, dietary intake, and presence of preoperative chronic malnutrition were interrelated and influenced the weight of the patient at all times during the postoperative follow-up (p < 0.05 for all values). The severity of the heart defect had no significant influence on the postoperative anthropometric measurements (p > 0.05). The lowest preoperative z scores for weight and height were observed in Group 3. Seven patients could not achieve the endpoint at the end of 12 months (4 in Group 3 and 3 in Group 2). Catch-up growth is attained mostly in the first year after corrective surgery. Delays in reaching z scores > -1 are observed in the chronically malnourished children. If adequate calories are provided and early corrective surgery is performed, the normal growth potential may be fulfilled.


Asunto(s)
Trastornos del Crecimiento/epidemiología , Cardiopatías Congénitas/cirugía , Estatura , Peso Corporal , Comorbilidad , Femenino , Cardiopatías Congénitas/epidemiología , Humanos , Lactante , Masculino , Desnutrición/epidemiología , Estado Nutricional , Periodo Posoperatorio , Estudios Prospectivos
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