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2.
J Virus Erad ; 9(1): 100319, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36970063

RESUMEN

Background & aims: Despite effective direct-acting antivirals (DAAs), hepatitis C virus (HCV) prevalence is high among people who inject drugs (PWIDs) and non-adherence to therapy remains a major obstacle towards HCV elimination in this subpopulation. To overcome this issue, we have combined ongoing opioid agonist therapy (OAT) with DAAs in a directly-observed therapy (DOT) setting. Method: From September 2014 until January 2021 PWIDs at high risk of non-adherence to DAA therapy, who were also on OAT, were included into this microelimination project. Individuals received their OAT and DAAs under supervision of healthcare workers as DOT in a pharmacy or low-threshold facility. Results: In total, 504 HCV RNA-positive PWIDs on OAT (387 men, 76.8%; median age: 38 years [IQR 33-45], HIV: 4.6%; hepatitis B: 1.4%) were included into this study. Two thirds reported ongoing intravenous drug use (IDU) and half of them had no permanent housing. Only 41 (8.1%) were lost to follow-up and two (0.4%) died of reasons unrelated to DAA toxicity. Overall, 90.7% of PWIDs achieved sustained virological response 12 weeks after treatment (SVR12) (95% CI: 88.1-93.2%). By excluding those lost to follow-up and hose who had died of causes unrelated to DAAs, the SVR12 rate was 99.1% (95% CI: 98.3-100.0%; modified intention-to-treat analysis). Four PWIDs (0.9%) experienced treatment failure. Over a median follow-up of 24 weeks (IQR 12-39), 27 reinfections (5.9%) were observed in individuals with the highest IDU rates (81.2%). Importantly, even though some were lost to follow-up, all completed their DAA treatment. By using DOT, adherence to DAAs was excellent with only a total of 86 missed doses (0.3% of 25,224 doses). Conclusions: In this difficult-to-treat population of PWIDs with high rates of IDU , coupling DAA treatment to OAT in a DOT setting resulted in high SVR12 rates equivalent to conventional treatment settings in non-PWID populations.

3.
Public Health ; 217: 155-163, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36893632

RESUMEN

OBJECTIVES: This study aimed to (1) encourage allocation of governmental and grant funds to the administration of local area health surveys and (2) illustrate the predictive impact of socio-economic resources on adult health status at the local area level to provide an example of how health surveys can identify residents with the greatest health needs. STUDY DESIGN: Randomly sampled and weight-adjusted regional household health survey (7501 respondents) analyzed with categorical bivariate and multivariate statistics, combined with Census data. Survey sample consists of the lowest, highest, and near highest ranked counties in the County Health Rankings and Roadmaps for Pennsylvania. METHODS: Socio-economic status (SES) is measured regionally with Census data consisting of seven indicators and individually with Health Survey data consisting of five indicators based on poverty level, overall household income, and education. Both of these composite measures are examined jointly for their predictive effects on a validated health status measure using binary logistic regression. RESULTS: Once county-level measures of SES and health status are broken down into smaller areas, better identification of pockets of health need is possible. This was most strongly revealed in an urban county, Philadelphia, which is ranked lowest of 67 counties on health measures in the state of Pennsylvania, yet when broken down into 'neighborhood clusters' contained both the highest- and lowest-ranked local area in a five-county region. Overall, regardless of the SES level of the County subdivision one lives in, a low-SES adult has close to six times greater odds of reporting 'fair or poor health status' than does a high-SES adult. CONCLUSION: Local health survey analysis can lead to a more precise identification of health needs than surveys attempting to cover broad areas. Low-SES communities within counties, and low-SES individuals, regardless of the community they live in, are substantially more likely to experience fair to poor health. This adds urgency to the need to implement and investigate socio-economic interventions, which can hopefully improve health and save healthcare costs. Novel local area research can identify the impact of intervening variables such as race in addition to SES to add more specificity in identifying populations with the greatest health needs.


Asunto(s)
Asignación de Recursos para la Atención de Salud , Evaluación de Necesidades , Adulto , Humanos , Estado de Salud , Encuestas Epidemiológicas , Philadelphia , Características de la Residencia/estadística & datos numéricos , Factores Socioeconómicos , Masculino , Femenino
4.
Water Res ; 231: 119650, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36702025

RESUMEN

Aeration is an energy-intensive process of aerobic biological wastewater treatment. An accurate model of oxygen transfer dynamics in activated sludge tanks would improve design and operation of aeration systems. Such a model should consider spatial and diurnal variation of α-factor as well as site-specific conditions that impact oxygen transfer. For this dynamic prediction a machine learning approach was used for the first time. The data-driven method was based on long-term ex-situ off-gas measurements with pilot-scale reactors (5.8 m height, 8.3 m3 vol) coupled to full-scale activated sludge tanks on the sites of two conventional and a two-stage activated sludge treatment plant. The ex-situ off-gas method allowed to quantify theoretical off-gas parameters in non-aerated zones and thus consider the whole activated sludge tank. We introduced the α0-factor to compare aerated and non-aerated zones under nonsteady-state conditions. Like the established α-factor for steady-state conditions, the α0-factor describes oxygen transfer inhibiting effects in activated sludge. α0-factor was lowest in upstream denitrification zones. This indicates an anoxic elimination of oxygen transfer inhibiting wastewater contaminants which improved oxygen transfer in subsequent aerobic zones. Random Forest models predicted α0-factor reliably in all examined activated sludge tanks even for stormwater events and seasonal variation. Model development only required online sensor data already available to operators. Our results suggest that machine learning models can dynamically predict α-factors in a variety of activated sludge processes, thus considering site-specific conditions in model training without manual calibration.


Asunto(s)
Aguas del Alcantarillado , Purificación del Agua , Oxígeno/análisis , Aguas Residuales , Reactores Biológicos , Purificación del Agua/métodos , Eliminación de Residuos Líquidos/métodos
5.
Eur J Paediatr Dent ; 23(2): 140-146, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35722846

RESUMEN

AIM: Despite the fact that ectodermal dysplasia (ED) is a rare disease, it is often seen in a tertiary clinic. ED affects ectodermal tissues such as skin, hair, teeth, nails, and sweat glands. Patients usually have sparse light hair, deformed nails, and dry skin. They suffer from dental abnormalities such as oligodontia (absence of 6 or more teeth) or complete anodontia; salivation can also be affected. The absence of teeth can be the overriding problem for both patients and their parents, and lead to substantial social ostracisation. This study aims to summarise the facts about the disease, especially dental treatment options based on data drawn from a representative Czech cohort. MATERIALS: The present article summarises the facts about ectodermal dysplasia (ED) in a cohort of 13 patients, where the following were evaluated: clinical manifestations of ED, pathogenic variants detected in selected candidate genes and dental treatment options from child removable dentures to fixed crowns and implants insertion. Three cases are described in detail and demonstrate approaches for different age groups. CONCLUSION: Early diagnosis and active cooperation between the geneticist and dentist will facilitate cooperation with parents and patients and assure secondary prevention. It is preferable that the geneticist understands dental treatment options and can discuss these with patients/parents.


Asunto(s)
Anodoncia , Displasia Ectodérmica , Anodoncia/terapia , Niño , Atención Odontológica , Displasia Ectodérmica/complicaciones , Displasia Ectodérmica/terapia , Humanos
7.
Strahlenther Onkol ; 198(6): 558-565, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35394144

RESUMEN

AIMS: Proton therapy (PT) represents an advanced form of radiotherapy with unique physical properties which could be of great advantage in reducing long-term radiation morbidity for cancer survivors. Here, we aim to describe the whole process leading to the clinical implementation of consolidative active scanning proton therapy treatment (PT) for mediastinal lymphoma. METHODS: The process included administrative, technical and clinical issues. Authorization of PT is required in all cases as mediastinal lymphoma is currently not on the list of diseases reimbursable by the Italian National Health Service. Technically, active scanning PT treatment for mediastinal lymphoma is complex, due to the interaction between actively scanned protons and the usually irregular and large volumes to be irradiated, the nearby healthy tissues and the target motion caused by breathing. A road map to implement the technical procedures was prepared. The clinical selection of patients was of utmost importance and took into account both patient and tumor characteristics. RESULTS: The first mediastinal lymphoma was treated at our PT center in 2018, four years after the start of the clinical activities. The treatment technique implementation included mechanical deep inspiration breath-hold simulation computed tomography (CT), clinical target volume (CTV)-based multifield optimization planning and plan robustness analysis. The ultimate authorization rate was 93%. In 4 cases a proton-photon plan comparison was required. Between May 2018 and February, 2021, 14 patients were treated with consolidative PT. The main clinical reasons for choosing PT over photons was a bulky disease in 8 patients (57%), patient's age in 11 patients (78%) and the proximity of the lymphoma to cardiac structures in 10 patients (71%). With a median follow-up of 15 months (range, 1-33 months) all patients but one (out-of-field relapse) are without evidence of disease, all are alive and no late toxicities were observed during the follow-up period. CONCLUSIONS: The clinical implementation of consolidative active scanning PT for mediastinal lymphoma required specific technical procedures and a prolonged experience with PT treatments. An accurate selection of patients for which PT could be of advantage in comparison with photons is mandatory.


Asunto(s)
Enfermedad de Hodgkin , Linfoma , Neoplasias del Mediastino , Terapia de Protones , Radioterapia de Intensidad Modulada , Estudios de Factibilidad , Enfermedad de Hodgkin/patología , Humanos , Linfoma/radioterapia , Neoplasias del Mediastino/diagnóstico por imagen , Neoplasias del Mediastino/radioterapia , Órganos en Riesgo/patología , Selección de Paciente , Terapia de Protones/métodos , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Medicina Estatal
8.
BMC Biotechnol ; 22(1): 13, 2022 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-35351081

RESUMEN

BACKGROUND: Type I interferons are widely used in research applications and as biotherapeutics. Current assays used to measure interferon concentrations, such as plaque reduction assays and ELISA, are expensive, technically challenging, and may take days to provide results. We sought to develop a robust and rapid assay to determine interferon concentrations produced from transiently transfected cell cultures. METHOD: Indirect quantification of recombinant interferon was evaluated using a novel bi-cistronic construct encoding the Foot-and-mouth disease virus 2A translational interrupter sequence to yield equimolar expression of Gaussia princeps luciferase and porcine interferon α. Direct quantification was evaluated by expression of a novel fusion protein comprised of Gaussia princeps luciferase and porcine type I interferon. Plasmids encoding constructs are transiently transfected into cell cultures and supernatant harvested for testing of luminescence, ELISA determined concentration, and anti-viral activity against vesicular stomatitis virus. RESULTS: Bi-cistronic constructs, utilized for indirect quantification, demonstrate both luciferase activity and anti-viral activity. Fusion proteins, utilized for direct quantification, retained secretion and luminescence however only the interferon α fusion protein had antiviral activity comparable to wildtype porcine interferon α. A strong linear correlation was observed between dilution and luminescence for all compounds over a dynamic range of concentrations. CONCLUSION: The correlation of antiviral and luciferase activities demonstrated the utility of this approach, both direct and indirect, to rapidly determine recombinant interferon concentrations. Concentration can be determined over a more dynamic concentration range than available ELISA based assays using this methodology.


Asunto(s)
Interferón Tipo I , Animales , Antivirales/farmacología , Interferón Tipo I/genética , Interferón-alfa/genética , Luciferasas/genética , Luciferasas/metabolismo , Luminiscencia , Porcinos
9.
Rev Sci Instrum ; 92(11): 113306, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34852560

RESUMEN

The upcoming commissioning of the superconducting (SC) continuous wave Helmholtz linear accelerators first of series cryomodule is going to demand precise alignment of the four internal SC cavities and two SC solenoids. For optimal results, a beam-based alignment method is used to reduce the misalignment of the whole cryomodule, as well as its individual components. A symmetric beam of low transverse emittance is required for this method, which is to be formed by a collimation system. It consists of two separate plates with milled slits, aligned in the horizontal and vertical direction. The collimation system and alignment measurements are proposed, investigated, and realized. The complete setup of this system and its integration into the existing environment at the GSI High Charge State Injector are presented, as well as the results of the recent reference measurements.

10.
Rev Sci Instrum ; 92(8): 083203, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34470420

RESUMEN

We present a novel ultrastable superconducting radio-frequency (RF) ion trap realized as a combination of an RF cavity and a linear Paul trap. Its RF quadrupole mode at 34.52 MHz reaches a quality factor of Q ≈ 2.3 × 105 at a temperature of 4.1 K and is used to radially confine ions in an ultralow-noise pseudopotential. This concept is expected to strongly suppress motional heating rates and related frequency shifts that limit the ultimate accuracy achieved in advanced ion traps for frequency metrology. Running with its low-vibration cryogenic cooling system, electron-beam ion trap, and deceleration beamline supplying highly charged ions (HCIs), the superconducting trap offers ideal conditions for optical frequency metrology with ionic species. We report its proof-of-principle operation as a quadrupole-mass filter with HCIs and trapping of Doppler-cooled 9Be+ Coulomb crystals.

11.
Water Sci Technol ; 83(11): 2778-2792, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34115631

RESUMEN

The objective of the present study is to investigate the different effects on the oxygen transfer of fine-bubble aeration systems in saline water. Compared to tap water, oxygen transfer increases due to the inhibition of bubble coalescence. In Part I of the present study, we investigated in laboratory-scale experiments the effect of design of diffuser membrane. The objective of Part II is the assessment of effects of different salts, diffuser type and diffuser density. We measured the concentration of various salts (MgCl2; CaCl2; Na2SO4; NaCl; KCl) above which coalescence is fully inhibited and oxygen transfer reaches its maximum (referred to as the critical coalescence concentration; CCC). For this purpose, we developed a new analytical approach, which enables investigation of the coalescence behaviour of any aeration system and (mixed) salt solution quickly and easily by evaluating the results of oxygen transfer tests. To investigate the transferability to large scale and the effect of diffuser type and density, we repeated lab-scale experiments in a 17,100 L pilot-scale test tank and carried out additional tests with tube and plate diffusers at different diffuser densities. The results show that despite the higher pressure drop, diffusers with dense slit density and smaller slits are to be recommended in order to improve efficiency of aeration systems in saline water.


Asunto(s)
Oxígeno , Purificación del Agua , Difusión , Aguas Salinas , Sales (Química) , Eliminación de Residuos Líquidos
13.
Anaesthesia ; 76 Suppl 4: 14-23, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33682097

RESUMEN

In the UK, the proportion of female medical students has remained static over the last decade, at around 55%; however, at consultant level, only 36.6% of doctors are women. The reasons for this drop in numbers are not clear. Given the increase in number of female doctors in training, the proportion of female doctors at consultant level is lower than might be expected. This article discusses issues affecting the female medical workforce in anaesthesia, intensive care and pain medicine. It explores how gender stereotypes and implicit gender bias can affect the way women are perceived in the workplace, especially in leadership positions, and discusses health issues particular to the female medical workforce. While the issues in this article may not affect all women, the cumulative effect of being subject to gender stereotypes within a workplace not designed to accommodate the health needs of women may contribute to a work environment that may promote the attrition of women from our specialties.


Asunto(s)
Recursos Humanos , Femenino , Personal de Salud , Humanos , Infertilidad/patología , Trastornos de la Menstruación/patología , Permiso Parental , Sexismo , Estereotipo
14.
Phys Med Biol ; 65(24): 245045, 2020 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-33157544

RESUMEN

A deeper understanding of biological mechanisms to promote more efficient treatment strategies in proton therapy demands advances in preclinical radiation research. However this is often limited by insufficient availability of adequate infrastructures for precision image guided small animal proton irradiation. The project SIRMIO aims at filling this gap by developing a portable image-guided research platform for small animal irradiation, to be used at clinical facilities and allowing for a precision similar to a clinical treatment, when scaled down to the small animal size. This work investigates the achievable dosimetric properties of different lowest energy clinical proton therapy beams, manipulated by a dedicated portable beamline including active focusing after initial beam energy degradation and collimation. By measuring the lateral beam size in air close to the beam nozzle exit and the laterally integrated depth dose in water, an analytical beam model based on the beam parameters of the clinical beam at the Rinecker Proton Therapy Center was created for the lowest available clinical beam energy. The same approach was then applied to estimate the lowest energy beam model of different proton therapy facilities, Paul Scherrer Institute, Centre Antoine Lacassagne, Trento Proton Therapy Centre and the Danish Centre for Particle Therapy, based on their available beam commissioning data. This comparison indicated similar beam properties for all investigated sites, with emittance values of a few tens of mm·mrad. Finally, starting from these beam models, we simulated propagation through a novel beamline designed to manipulate the beam energy and size for precise small animal irradiation, and evaluated the resulting dosimetric properties in water. For all investigated initial clinical beams, similar dosimetric results suitable for small animal irradiation were found. This work supports the feasibility of the proposed SIRMIO beamline, promising suitable beam characteristics to allow for precise preclinical irradiation at clinical treatment facilities.


Asunto(s)
Terapia de Protones/instrumentación , Animales , Estudios de Factibilidad , Radiometría , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Radioterapia Guiada por Imagen , Sincrotrones
16.
J Phys Condens Matter ; 32(36): 36LT01, 2020 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-32369787

RESUMEN

The thermodynamics in spin-ice systems are governed by emergent magnetic monopole excitations and, until now, the creation of a pair of these topological defects was associated with one specific pair-creation energy. Here, we show that the electric dipole moments inherent to the magnetic monopoles lift the degeneracy of their creation process and lead to a splitting of the pair-creation energy. We consider this finding to extend the model of magnetic relaxation in spin-ice systems and show that an electric dipole interaction in the theoretically estimated order of magnitude leads to a splitting which can explain the controversially discussed discrepancies between the measured temperature dependence of the magnetic relaxation times and previous theory. By applying our extended model to experimental data of, various spin-ice systems, we show its universal applicability and determine a dependence of the electric dipole interaction on the system parameters, which is in accordance with the theoretical model of electric dipole formation.

17.
Nature ; 578(7793): 60-65, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31996851

RESUMEN

Precision spectroscopy of atomic systems1 is an invaluable tool for the study of fundamental interactions and symmetries2. Recently, highly charged ions have been proposed to enable sensitive tests of physics beyond the standard model2-5 and the realization of high-accuracy atomic clocks3,5, owing to their high sensitivity to fundamental physics and insensitivity to external perturbations, which result from the high binding energies of their outer electrons. However, the implementation of these ideas has been hindered by the low spectroscopic accuracies (of the order of parts per million) achieved so far6-8. Here we cool trapped, highly charged argon ions to the lowest temperature reported so far, and study them using coherent laser spectroscopy, achieving an increase in precision of eight orders of magnitude. We use quantum logic spectroscopy9,10 to probe the forbidden optical transition in 40Ar13+ at a wavelength of 441 nanometres and measure its excited-state lifetime and g-factor. Our work unlocks the potential of highly charged ions as ubiquitous atomic systems for use in quantum information processing, as frequency standards and in highly sensitive tests of fundamental physics, such as searches for dark-matter candidates11 or violations of fundamental symmetries2.

18.
AJNR Am J Neuroradiol ; 41(1): 147-154, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31896570

RESUMEN

BACKGROUND AND PURPOSE: Temporal lobe epilepsy, structural or nonlesional, may negatively affect language function. However, little is known about the lesion-specific influence on language networks. We hypothesized that different epileptogenic lesions are related to distinct alterations in the functional language connectome detected by fMRI. MATERIALS AND METHODS: One hundred one patients with epilepsy due to mesiotemporal sclerosis (21 left, 22 right), low-grade mesiotemporal tumors (12 left), or nonlesional temporal lobe epilepsy (22 left, 24 right) and 22 healthy subjects performed 3T task-based language fMRI. Task-based activation maps (laterality indices) and functional connectivity analysis (global and connectivity strengths between language areas) were correlated with language scores. RESULTS: Laterality indices based on fMRI activation maps failed to discriminate among patient groups. Functional connectivity analysis revealed the most extended language network alterations in left mesiotemporal sclerosis (involving the left temporal pole, left inferior frontal gyrus, and bilateral premotor areas). The other patient groups showed less extended but also predominantly ipsilesional network changes compared with healthy controls. Left-to-right hippocampal connectivity strength correlated positively with naming function (P = .01), and connectivity strength between the left Wernicke area and the left hippocampus was linked to verbal fluency scores (P = .01) across all groups. CONCLUSIONS: Different pathologies underlying temporal lobe epilepsy are related to distinct alterations of the functional language connectome visualized by fMRI functional connectivity analysis. Network analysis allows new insights into language organization and provides possible imaging biomarkers for language function. These imaging findings emphasize the importance of a personalized treatment strategy in patients with epilepsy.


Asunto(s)
Encéfalo/diagnóstico por imagen , Conectoma , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Lenguaje , Red Nerviosa/diagnóstico por imagen , Adulto , Encéfalo/patología , Encéfalo/fisiopatología , Epilepsia del Lóbulo Temporal/patología , Epilepsia del Lóbulo Temporal/fisiopatología , Femenino , Lateralidad Funcional/fisiología , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Red Nerviosa/fisiología , Red Nerviosa/fisiopatología , Estudios Retrospectivos , Adulto Joven
19.
Environ Sci Process Impacts ; 22(1): 105-120, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31790114

RESUMEN

A screening procedure for the identification of potential emerging chemical risks in the food and feed chain developed in a previous EFSA-sponsored pilot study was applied to 15021 substances registered under the REACH Regulation at the time of evaluation. Eligible substances were selected from this dataset by excluding (a) intermediates handled under strictly controlled conditions, (b) substances lacking crucial input data and (c) compounds considered to be outside the applicability domain of the models used. Selection of eligible substances resulted in a considerable reduction to 2336 substances. These substances were assessed and scored for environmental release (tonnage and use information from REACH registration dossiers), biodegradation (predictions from BIOWIN models 3, 5 and 6 evaluated in a battery approach), bioaccumulation in food/feed (ACC-HUMANsteady modelling) and chronic human health hazards (classification according to the CLP Regulation for carcinogenicity, mutagenicity, reproductive toxicity and repeated dose toxicity as well as IARC classification for carcinogenicity). Prioritisation based on the scores assigned and additional data curation steps identified 212 substances that are considered potential emerging risks in the food chain. Overall, 53% of these substances were prioritised due to chronic hazards identified in REACH registrations dossiers only (i.e. hazards not identified in classifications from other sources). Bioaccumulation in food and feed predicted on the basis of ACC-HUMANsteady modelling identified many substances that are not considered bioaccumulative in aquatic or terrestrial organisms based on screening criteria of the relevant ECHA guidance documents. Furthermore, 52% of the priority substances have not yet been assessed for their presence in food/feed by EU regulatory agencies. This finding and illustrative examples suggest that the screening procedure identified substances that have the potential to be emerging chemical risks in the food chain. Future research should investigate whether they actually represent emerging chemical risks as defined in EFSA's mandate.


Asunto(s)
Contaminantes Ambientales , Cadena Alimentaria , Sustancias Peligrosas , Biodegradación Ambiental , Humanos , Proyectos Piloto , Medición de Riesgo
20.
Phys Med ; 68: 83-87, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31765885

RESUMEN

PURPOSE: To perform the first dosimetric intercomparison for proton beams in Italy using ionization chambers, according to the IAEA TRS-398 code of practice. METHODS: Measurement sites included: National Center for Oncological Hadron Therapy (CNAO, Pavia), Center for Proton Therapy (CTP, Trento) and Center for Hadron Therapy and for advanced Nuclear Applications (CATANA, Catania). For comparison we also included a 6 MV photon beam produced at Istituti Clinici Scientifici Maugeri (ICSM, Pavia). For proton beams, both single pseudo-monoenergetic layers (in order to obtain a planned dose of 2 Gy at the reference depth of 2 cm in a water phantom) and Spread-out Bragg peaks (SOBP) have been delivered. Measurements were performed with a PTW Farmer 30010-1 and a PTW Advanced Markus type 34,045 ionization chamber. RESULTS: Data obtained at CATANA, CNAO and CPT in terms of absorbed dose to water depth show good consistency within the experimental uncertainties, with a weighted mean of 1.99 ± 0.01 Gy and a standard error of 0.003 Gy, with reference to a nominal dose of 2 Gy as designed by the treatment planning system. CONCLUSIONS: The results showed a standard deviation of less than 1% for single layer and SOBP beams, for all chambers and a percent deviation less than 1.5% for single layer measurements. The weighted means of the absorbed doses for clinical proton beams (118.19 MeV and 173.61 MeV) are consistent within less than 1%. These results agree within the 1.5% difference considered acceptable for national dose intercomparison.


Asunto(s)
Terapia de Protones , Dosis de Radiación , Radiometría/instrumentación , Italia , Dosificación Radioterapéutica
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