72 research outputs found
First tests for an online treatment monitoring system with in-beam PET for proton therapy
PET imaging is a non-invasive technique for particle range verification in
proton therapy. It is based on measuring the beta+ annihilations caused by
nuclear interactions of the protons in the patient. In this work we present
measurements for proton range verification in phantoms, performed at the CNAO
particle therapy treatment center in Pavia, Italy, with our 10 x 10 cm^2 planar
PET prototype DoPET. PMMA phantoms were irradiated with mono-energetic proton
beams and clinical treatment plans, and PET data were acquired during and
shortly after proton irradiation. We created 1-D profiles of the beta+ activity
along the proton beam-axis, and evaluated the difference between the proximal
rise and the distal fall-off position of the activity distribution. A good
agreement with FLUKA Monte Carlo predictions was obtained. We also assessed the
system response when the PMMA phantom contained an air cavity. The system was
able to detect these cavities quickly after irradiation.Comment: 11 pages, 6 figures, Proceedings for International Workshop on
Radiation Imaging Detectors, 201
Medico-legal assessment of personal damage in older people: report from a multidisciplinary consensus conference
Ageing of the global population represents a challenge for national healthcare systems and healthcare professionals, including
medico-legal experts, who assess personal damage in an increasing number of older people. Personal damage evaluation in older
people is complex, and the scarcity of evidence is hindering the development of formal guidelines on the subject. The main
objectives of the first multidisciplinary Consensus Conference on Medico-Legal Assessment of Personal Damage in Older
People were to increase knowledge on the subject and establish standard procedures in this field. The conference, organized
according to the guidelines issued by the Italian National Institute of Health (ISS), was held in Bologna (Italy) on June 8, 2019
with the support of national scientific societies, professional organizations, and stakeholders. The Scientific Technical Committee
prepared 16 questions on 4 thematic areas: (1) differences in injury outcomes in older people compared to younger people and
their relevance in personal damage assessment; (2) pre-existing status reconstruction and evaluation; (3) medico-legal examination
procedures; (4) multidimensional assessment and scales. The Scientific Secretariat reviewed relevant literature and documents,
rated their quality, and summarized evidence. During conference plenary public sessions, 4 pairs of experts reported on
each thematic area. After the last session, a multidisciplinary Jury Panel (15 members) drafted the consensus statements. The
present report describes Conference methods and results, including a summary of evidence supporting each statement, and areas
requiring further investigation. The methodological recommendations issued during the Conference may be useful in several
contexts of damage assessment, or to other medico-legal evaluation fields
Patronage-Preserving Federalism? Legislative Malapportionment and Subnational Fiscal Policies in Argentina
The Presidency and the Executive Branch in Latin America: What We Know and What We Need to Know
The presidential politics literature depicts presidents either as all- powerful actors or figureheads and seeks to explain outcomes accordingly. Th e president and the executive branch are nonetheless usually treated as black boxes, particularly i n developing countries, even though the presidency has evolved into an extremely complex branch of government. While these developments have been studied in the U nited States, far less i s known in other countries, particularly in Latin America, where presi dential systems have been considered the source of all goods and evils. To help close the knowledge gap and explore differences in policymaking characteristics not only between Latin America and the US but also across Latin American countries, this paper s ummarizes the vast literature on the organization and resources of the Executive Branch in the Americas and sets a research agenda for the study of Latin American presidencies.Fil: Bonvecchi, Alejandro. Universidad Torcuato Di Tella. Departamento de Ciencia PolĂtica y Estudios Internacionales; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Scartascini, Juan Carlos. Banco Interamericano de Desarrollo; Estados Unido
Inferring causal molecular networks: empirical assessment through a community-based effort.
It remains unclear whether causal, rather than merely correlational, relationships in molecular networks can be inferred in complex biological settings. Here we describe the HPN-DREAM network inference challenge, which focused on learning causal influences in signaling networks. We used phosphoprotein data from cancer cell lines as well as in silico data from a nonlinear dynamical model. Using the phosphoprotein data, we scored more than 2,000 networks submitted by challenge participants. The networks spanned 32 biological contexts and were scored in terms of causal validity with respect to unseen interventional data. A number of approaches were effective, and incorporating known biology was generally advantageous. Additional sub-challenges considered time-course prediction and visualization. Our results suggest that learning causal relationships may be feasible in complex settings such as disease states. Furthermore, our scoring approach provides a practical way to empirically assess inferred molecular networks in a causal sense
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Radiological Diagnosis of Pancreatic Neuroendocrine Neoplasms
Neuroendocrine tumors (NETs) pose peculiar problems for imaging techniques in relation to their functional state. In functioning NETs - in which the diagnosis is mainly based on clinical and laboratory findings - the primary imaging \u201cgoal\u201d is the localization of the hormonal hypersecretion source/sources; in nonfunctioning NETs \u2013 which appear as symptomatic masses or as incidental findings \u2013 the priority questions are represented both by the identification and correct histological typing. For all NETs \u2013 regardless of their functional state - an accurate staging is also required, as they are often malignant. The basic imaging modality is MDCT for both diagnosis and staging; although MRI is generally superior to CT for liver metastasis detection, the choice between the two methods depends on the local availability and expertise Imaging techniques have an important role also in the follow-up for both diagnosis of recurrent disease and therapy monitoring. In this respect the RECIST criteria, which were designed for general oncology, are less suited; new criteria, which take the special characteristics of NETs into account, are currently under developmen
Ability of specific and nonspecific signs of multidetector computed tomography (MDCT) in the diagnosis of blunt surgically important bowel and mesenteric injuries
To determine the accuracy of MDCT in the evaluation of blunt surgically relevant bowel and/or mesenteric injuries (BMIs) using single specific CT signs together with specific pairs of nonspecific signs.Fifty-four patients examined with MDCT were divided into two groups: a 'surgical' group of 20 patients-which underwent surgery for blunt BMIs-and a control group of 34 'nonsurgical' trauma patients. Two radiologists with different experience performed a double-blind retrospective evaluation of the images, classifying the patients in the two groups by using only single specific signs; then, the images were reviewed in consensus with a third radiologist and sensitivity and specificity were calculated. Subsequently, the frequency of every single sign and of every possible combination of nonspecific signs in the two groups was registered, to find combinations present only in the surgical group; sensitivity and specificity were calculated by using even those specific combinations.At the first consensual evaluation, sensitivity and specificity were 75 and 100%, respectively. Two combinations of nonspecific signs (focal wall thickening + extraluminal air; focal wall thickening + seat belt sign) were found only in surgical patients that did not present any single specific sign: Sensitivity calculated adding those two combinations was 95%, without a decrease in specificity.MDCT is an accurate technique in the evaluation of blunt surgically relevant BMIs. The single specific CT signs were sufficient for the diagnosis in only 75% of the cases; adding the two specific combinations allowed an increase in sensitivity of 20%
In-beam PET data characterization with the large area DoPET prototype
Range verification with in-beam PET techniques is a powerful tool for monitoring the correctness of dose delivery in particle therapy. Among the major limitations of in-beam PET systems are the limited detectors size due to the constrained space in which they can be placed to allow the irradiation, and the necessity of a high read-out modularization, due to high activity rates during the irradiation. In this work we present the data acquired at the CNAO (Centro Nazionale di Adroterapia Oncologica) treatment center in Pavia, Italy, with the new DoPET system, specifically designed to operate in in-beam conditions. The new prototype consists of two planar 15cm x 15cm LYSO-based detectors, read out by 9 PMT detector modules each. In particular, we test the capability of our system to determine particle range in various irradiation conditions. Several plastic phantoms were irradiated at the CNAO treatment centre with protons and carbon ions of various energies. The used dose in treatment plans is 2 Gy and the monitoring feedback is produced in a few minutes after the end of the treatment
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