408 research outputs found

    A GATE-based Monte Carlo simulation of a dual-layer pixelized gadolinium oxyorthosilicate (GSO) detector performance and response for micro PET scanner

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    The purpose of this study was to simulate the GSO detector of a micro PET using GATE simulation platform. The performance and responses of the simulated GSO detector assembly were evaluated by comparing the simulated data to the experimental and XCOM data to validate the simulation platform and procedure. Based on NEMA NU-4 2008 protocols, the performance of GSO detector in terms of sensitivity was simulated and compared to the experimental data. Similarly, the GSO detector response to photons interaction was simulated and compared against the XCOM data for absorbed intensity ratio in the GSO detector and survived intensity ratio in Pb blocks. Results showed that simulated and experimental sensitivities agreed well with R2 of 0.995 and two overlapping bands at 95% confidence. An agreement with R2 of 0.972 and 0.973 as well as with overlapping bands at 95% confidence was obtained in simulated and XCOM data for absorbed and survived intensity ratio in the GSO detector and Pb blocks, respectively. The observed agreements demonstrate the accuracy of the simulation method to mimic the behaviour of the GSO detector. The validated GATE algorithm for micro PET scanner is therefore recommended for simulation and optimisation of collimator design in further studies. Keywords: GATE simulation, Experimental data, XCOM data, GSO detector, micro PET. &nbsp

    Iringa Regional and District Projections.

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    This report presents population projections for the period 2003 to 2025 for Iringa Region and its districts. The projections were made using a Cohort Component Method (Spectrum System), whereby three components responsible for population change, namely: mortality, fertility and migration were projected separately as well as HIV/AIDS prevalence. The projected components were then applied to 2002 midyear base population in order to come up with the desired projections from 2003 to 2025. The report gives mortality, fertility, migration and HIV/AIDS assumptions, and shows Iringa’s demographic and socio-economic future trends. The results include estimated population by sex in single years and five-year age groups as well as some demographic indicators. Population growth for the period 2003 to 2025 shows a decrease in growth rates. The projections show that population growth rate will decrease from 1.6 percent in 2003 (with a population of 1,520,891) to 0.4 percent in 2025 (with a population of 2,019,217). Sex Ratio at birth is projected to increase from 90 male births per 100 females in 2003 to 99 male births per 100 females in 2025. Mortality estimates show that Infant Mortality Rate (IMR) is expected to decline for both sexes from 127 deaths per 1,000 live births in 2003 to 78 deaths per 1,000 live births in 2025. Under Five Mortality Rate (U5MR) for both sexes will also decline from 207 deaths per 1,000 live births in 2003 to 122 deaths per 1,000 live births in the year 2025. The mortality projected estimates further show that the life expectancy at birth for both males and females stands at 45 years in 2003. Life expectancy at birth for Iringa will decline from 45 years in 2003 to 44 years in 2025 for both sexes. For male population, life expectancy at birth will remain at the same level of 45 years in year 2003 and year 2025, while for female population the life expectancy at birth will decline from 45 years in 2003 to 43 years in 2025. On fertility, TFR will decline from 4.9 children per woman in 2003 to 2.6 children per woman in 2025.\u

    Dar es Salaam Regional and District Projections.

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    This report presents population projections for the period 2003 to 2025 for Dar es Salaam Region. The projections were made using a Cohort Component Method (Spectrum System), whereby three components responsible for population change, namely: mortality, fertility and migration were projected separately as well as HIV/AIDS prevalence. The projected components were then applied to 2002 midyear base population in order to come up with the desired projections from 2003 to 2025. The report gives mortality, fertility, migration and HIV/AIDS assumptions, and shows Dar es Salaam’s demographic and socio-economic future trends. The results include estimated population by sex in single years and five-year age groups as well as some demographic indicators. Population growth for the period 2003 to 2025 shows a decrease in growth rates. The projections show that population growth rate will decrease from 1.99 percent in 2003 (with a population of 2,535,594) to 0.27 percent in 2025 (with a population of 3,055,456). Sex Ratio at birth is projected to increase slightly from 102 male per 100 females in 2003 to 103 male per 100 females in 2025. Mortality estimates show that Infant Mortality Rate (IMR) is expected to decline for both sexes from 80 deaths per 1,000 live births in 2003 to 49 deaths per 1,000 live births in 2025. Under Five Mortality Rate (U5MR) for both sexes will also decline from 122 deaths per 1,000 live births in 2003 to 71 deaths per 1,000 live births in the year 2025. As expected, the mortality projected estimates further show that the life expectancy at birth for females is higher compared to that of males. Life expectancy at birth for Dar es Salaam will decline from 55 years in 2003 to 52 years in 2025 for both sexes. For male population, life expectancy at birth will almost remain at 53 years for the whole period. For female population, the life expectancy at birth will decline from 57 years in 2003 to 52 years in 2025. On fertility, TFR will decline from 2.7 children per woman in 2003 to about 2 children per woman in 2025.\u

    End-colostomy diverticulitis with parastomal phlegmon: A case report.

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    Acute colonic diverticulitis is a well-known surgical emergency, which occurs in about 10 percent of patients known for diverticulosis. The case of a 77-year-old woman is reported, with past history of abdominoperineal resection with end-colostomy for low rectal adenocarcinoma, and who developed an acute colonic diverticulitis in a subcutaneous portion of colostomy with parastomal phlegmon. Initial computed tomography imaging demonstrated a significant submucosal parietal edema with local fat tissues infiltration in regard of 3 diverticula. A two-step treatment was decided: first a nonoperative treatment was initiated with 2 weeks antibiotics administration, followed by, 6 weeks after, a segmental resection of the terminal portion of the colon with redo of a new colostomy by direct open approach. Patient was discharged on the second postoperative day without complications. Follow-up at 2 weeks revealed centimetric dehiscence of the stoma, which was managed conservatively until sixth postoperative week by stomatherapists. Treatment of acute diverticulitis with parastomal phlegmon in a patient with end-colostomy could primary be nonoperative. Delayed surgical treatment with segmental colonic resection was proposed to avoid recurrence and potential associated complications

    The "Real R0": A Resection Margin Smaller Than 0.1 cm is Associated with a Poor Prognosis After Oncologic Esophagectomy.

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    Although resection margin (R) status is a widely used prognostic factor after esophagectomy, the definition of positive margins (R1) is not universal. The Royal College of Pathologists considers R1 resection to be a distance less than 0.1 cm, whereas the College of American Pathologists considers it to be a distance of 0.0 cm. This study assessed the predictive value of R status after oncologic esophagectomy, comparing survival and recurrence among patients with R0 resection (> 0.1-cm clearance), R0+ resection (≤ 0.1-cm clearance), and R1 resection (0.0-cm clearance). The study enrolled all eligible patients undergoing curative oncologic esophagectomy between 2012 and 2018. Clinicopathologic features, survival, and recurrence were compared for R0, R0+, and R1 patients. Categorical variables were compared with the chi-square or Fisher's test, and continuous variables were compared with the analysis of variance (ANOVA) test, whereas the Kaplan-Meier method and Cox regression were used for survival analysis. Among the 160 patients included in this study, 113 resections (70.6%) were R0, 34 (21.3%) were R0+, and 13 (8.1%) were R1. The R0 patients had a better overall survival (OS) and disease-free survival (DFS) than the R0+ and R1 patients. The R0+ resection offered a lower long-term recurrence risk than the R1 resection, and the R status was independently associated with DFS, but not OS, in the multivariate analysis. Both the R0+ and R1 patients had significantly more adverse histologic features (lymphovascular and perineural invasion) than the R0 patients and experienced more distant and locoregional recurrence. Although R status is an independent predictor of DFS after oncologic esophagectomy, the < 0.1-cm definition for R1 resection seems more appropriate than the 0.0-cm definition as an indicator of poor tumor biology, long-term recurrence, and survival

    Preoperative hiatal hernia in esophageal adenocarcinoma; does it have an impact on patient outcomes?

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    The impact of hiatal hernia (HH) on oncologic outcomes of patients with esophageal adenocarcinoma (AC) remains unclear. The aim of this study was to assess the effect of pre-existing HH (≥3 cm) on histologic response after neoadjuvant treatment (NAT), overall (OS) and disease-free survival (DFS). All consecutive patients with oncological esophagectomy for AC from 2012 to 2018 in our center were eligible for assessment. Categorical variables were compared with the X <sup>2</sup> or Fisher's test, continuous ones with the Mann-Whitney-U test, and survival with the Kaplan-Meier and log-rank test. Overall, 101 patients were included; 33 (32.7%) had a pre-existing HH. There were no baseline differences between HH and non-HH patients. NAT was used in 81.8% HH and 80.9% non-HH patients (p = 0.910), most often chemoradiation (63.6% and 57.4% respectively, p = 0.423). Good response to NAT (TRG 1-2) was observed in 36.4% of HH versus 32.4% of non-HH patients (p = 0.297), whereas R0 resection was achieved in 90.9% versus 94.1% respectively (p = 0.551). Three-year OS was comparable for the two groups (52.4% in HH, 56.5% in non-HH patients, p = 0.765), as was 3-year DFS (32.7% for HH versus 45.6% for non-HH patients, p = 0.283). HH ≥ 3 cm are common in patients with esophageal AC, concerning 32.7% of all patients in this series. However, its presence was neither associated with more advanced disease upon diagnosis, worse response to NAT, nor overall and disease-free survival. Therefore, such HH should not be considered as risk factor that negatively affects oncological outcome after multimodal treatment of esophageal AC

    A Comprehensive Review of Prognostic Factors in Patients with Gastric Adenocarcinoma.

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    Gastric adenocarcinoma remains associated with a poor long-term survival, despite recent therapeutical advances. In most parts of the world where systematic screening programs do not exist, diagnosis is often made at advanced stages, affecting long-term prognosis. In recent years, there is increasing evidence that a large bundle of factors, ranging from the tumor microenvironment to patient ethnicity and variations in therapeutic strategy, play an important role in patient outcome. A more thorough understanding of these multi-faceted parameters is needed in order to provide a better assessment of long-term prognosis in these patients, which probably also require the refinement of current staging systems. This study aims to review existing knowledge on the clinical, biomolecular and treatment-related parameters that have some prognostic value in patients with gastric adenocarcinoma
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