Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Ann Oncol ; 32(1): 113-119, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33098994

RESUMEN

BACKGROUND: Patients with cancer have high risk for severe complications and poor outcome to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related disease [coronavirus disease 2019 (COVID-19)]. Almost all subjects with COVID-19 develop anti-SARS-CoV-2 immunoglobulin G (IgG) within 3 weeks after infection. No data are available on the seroconversion rates of cancer patients and COVID-19. PATIENTS AND METHODS: We conducted a multicenter, observational, prospective study that enrolled (i) patients and oncology health professionals with SARS-CoV-2 infection confirmed by real-time RT-PCR assays on nasal/pharyngeal swab specimens; (ii) patients and oncology health professionals with clinical or radiological suspicious of infection by SARS-CoV-2; and (iii) patients with cancer who are considered at high risk for infection and eligible for active therapy and/or major surgery. All enrolled subjects were tested with the 2019-nCoV IgG/IgM Rapid Test Cassette, which is a qualitative membrane-based immunoassay for the detection of IgG and IgM antibodies to SARS-CoV-2. The aim of the study was to evaluate anti-SARS-CoV-2 seroconversion rate in patients with cancer and oncology health care professionals with confirmed or clinically suspected COVID-19. RESULTS: From 30 March 2020 to 11 May 2020, 166 subjects were enrolled in the study. Among them, cancer patients and health workers were 61 (36.7%) and 105 (63.3%), respectively. Overall, 86 subjects (51.8%) had confirmed SARS-CoV-2 diagnosis by RT-PCR testing on nasopharyngeal swab specimen, and 60 (36.2%) had a clinical suspicious of COVID-19. Median time from symptom onset (for cases not confirmed by RT-PCR) or RT-PCR confirmation to serum antibody test was 17 days (interquartile range 26). In the population with confirmed RT-PCR, 83.8% of cases were IgG positive. No difference in IgG positivity was observed between cancer patients and health workers (87.9% versus 80.5%; P = 0.39). CONCLUSIONS: Our data indicate that SARS-CoV-2-specific IgG antibody detection do not differ between cancer patients and healthy subjects.


Asunto(s)
COVID-19 , Neoplasias , Anticuerpos Antivirales , Personal de Salud , Humanos , Inmunoglobulina M , Neoplasias/epidemiología , Estudios Prospectivos , SARS-CoV-2 , Sensibilidad y Especificidad , Seroconversión
2.
Phys Rev Lett ; 120(23): 232502, 2018 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-29932707

RESUMEN

We report the result of the search for neutrinoless double beta decay of ^{82}Se obtained with CUPID-0, the first large array of scintillating Zn^{82}Se cryogenic calorimeters implementing particle identification. We observe no signal in a 1.83 kg yr ^{82}Se exposure, and we set the most stringent lower limit on the 0νßß ^{82}Se half-life T_{1/2}^{0ν}>2.4×10^{24} yr (90% credible interval), which corresponds to an effective Majorana neutrino mass m_{ßß}<(376-770) meV depending on the nuclear matrix element calculations. The heat-light readout provides a powerful tool for the rejection of α particles and allows us to suppress the background in the region of interest down to (3.6_{-1.4}^{+1.9})×10^{-3} counts/(keV kg yr), an unprecedented level for this technique.

3.
Oral Dis ; 21(4): 462-9, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25439053

RESUMEN

OBJECTIVES: Oral squamous cell carcinoma (OSCC) represents about 90% of all oral neoplasms with a poor clinical prognosis. To improve survival of OSCC patients, it is fundamental to understand the basic molecular mechanisms characterizing oral carcinogenesis. Dysregulation of oncogenes and tumor suppressor genes seems to play a central role in tumorigenesis, including malignant transformation of the oral cavity. MATERIALS AND METHODS: We analyzed the expression levels of the pro-oncogenic transcription factor Pokemon through real-time PCR, Western blot and immunohistochemistry in tumor, and normal oral tissue samples obtained from 22 patients with OSCC. The relationship between tumor characteristics and the level of Pokemon intratumor expression was also analyzed. RESULTS: Pokemon was significantly downregulated in OSCC. In particular, both mRNA and protein levels (tumor vs normal tissue) inversely correlated with histological grading, suggesting its potential role as a prognostic factor for OSCC. Moreover, a significant inverse correlation was found between Pokemon protein expression levels (OSCC vs normal oral mucosa) and tumor size, supporting the hypothesis that Pokemon could play an important role in the early phase of tumor expansion. CONCLUSION: This work shows that reduced expression of Pokemon is a peculiar feature of OSCC. Additional studies may establish the effective role of Pokemon in oral tumorigenesis.


Asunto(s)
Carcinogénesis/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Neoplasias de la Boca/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/biosíntesis , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinogénesis/metabolismo , Carcinogénesis/patología , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Proteínas de Unión al ADN/biosíntesis , Regulación hacia Abajo , Femenino , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/patología , Humanos , Masculino , Persona de Mediana Edad , Mucosa Bucal/patología , Neoplasias de la Boca/metabolismo , Neoplasias de la Boca/patología , Proto-Oncogenes Mas , Proto-Oncogenes , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Carcinoma de Células Escamosas de Cabeza y Cuello , Factores de Transcripción/biosíntesis
4.
Phys Med ; 108: 102545, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37021607

RESUMEN

Radio-Guided Surgery (RGS) is a nuclear medicine technique to support the surgeon during surgery towards a complete tumor resection. It is based on intraoperative detection of radiation emitted by a radio-pharmaceutical that bounds selectively to tumoral cells. In the past years, an approach that exploits ß- emitting radiotracers has been pursued to overtake some limitations of the traditional RGS based on γ emission. A particle detector dedicated to this application, demonstrating very high efficiency to ß- particles and remarkable transparency to photons, has been thus developed. As a by-product, its characteristics suggested the possibility to utilize it with ß+ emitting sources, more commonly in use in nuclear medicine. In this paper, performances of such detector on 18F liquid sources are estimated by means of Monte Carlo simulations (MC) and laboratory measurements. The experimental setup with a 18F saline solution comprised a "positron signal" spot (a 7 × 10 mm cylinder representing the tumor residual), and a surrounding "far background" volume, that represented for the detector an almost isotropic source of annihilation photons. Experimental results show good agreement with MC predictions, thus confirming the expected performances of the detector with 18F, and the validity of the developed MC simulation as a tool to predict the gamma background determined by a diffuse source of annihilation photons.


Asunto(s)
Neoplasias , Cirugía Asistida por Computador , Humanos , Partículas beta , Simulación por Computador , Método de Montecarlo , Fotones , Tomografía de Emisión de Positrones/métodos
5.
Phys Med Biol ; 68(19)2023 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-37747087

RESUMEN

One of today's main challenges in molecular radiation therapy is to assess an individual dosimetry that allows treatment to be tailored to the specific patient, in accordance with the current paradigm of 'personalized medicine'. The evaluation of the absorbed doses for tumor and organs at risk in molecular radiotherapy is typically based on MIRD schema acquiring few experimental points for the assessement of biokinetic parameters. WIDMApp, the wearable individual dose monitoring apparatus, is an innovative approach for internal dosimetry based on a wearable radiation detecting system for individual biokinetics sampling, a Monte Carlo simulation for particle interaction, and an unfolding algorithm for data analysis and integrated activity determination at organ level. A prototype of a WIDMApp detector element was used to record the photon emissions in a body phantom containing 3 spheres with liquid sources (18F,64Cu and99mTc) to simulate organs having different washout. Modelling the phantom geometry on the basis of a CT scan imaging, the Monte Carlo simulation computed the contribution of each emitting sphere to the signal detected in 3 positions on the phantoms surface. Combining the simulated results with the data acquired for 120 h, the unfolding algorithm deconvolved the detected signal and assessed the decay half-life (T1/2) and initial activity values (A(0)) that best reproduces the observed exponential decays. A 3%-18% level of agreement is found between the actualA(0) andT1/2values and those obtained by means of the minimization procedure based on the Monte Carlo simulation. That resulted in an estimation of the cumulated activity <15%. Moreover, WIDMApp data redundancy has been used to mitigate some experimental occurrences that happened during data taking. A first experimental test of the WIDMApp approach to internal radiation dosimetry is presented. Studies with patients are foreseen to validate the technique in a real environment.


Asunto(s)
Neoplasias , Radiometría , Humanos , Radiometría/métodos , Tomografía Computarizada por Rayos X/métodos , Simulación por Computador , Algoritmos , Fantasmas de Imagen , Método de Montecarlo
6.
ESMO Open ; 7(2): 100428, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35272131

RESUMEN

Since its first approval in 2006, 1 year of adjuvant trastuzumab has been the standard of care for early-stage HER2-positive breast cancer. Nevertheless, the optimal duration of adjuvant trastuzumab was uncertain, and the standard 12-month duration has been questioned by a number of different trials. Although most of these studies were formally negative, a patient-level meta-analysis presented at the 2021 European Society for Medical Oncology (ESMO) meeting first showed the non-inferiority of 6-month trastuzumab. Through this review, we sought to take a closer look at the meta-analysis and the included trials to explain why we believe that non-inferiority should be interpreted with caution. Indeed, here we underline how the meta-analysis' results were mainly driven by the PERSEPHONE study, an old trial that tested non-standard chemo-trastuzumab regimens in a relatively low-risk population with doubtful endpoints. In summary, considering all the limitations of this analysis and the increasing use of effective anthracycline-free de-escalation strategies, we are convinced that 1-year trastuzumab should remain the standard of care.


Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama/tratamiento farmacológico , Quimioterapia Adyuvante/métodos , Supervivencia sin Enfermedad , Femenino , Humanos , Receptor ErbB-2/análisis , Receptor ErbB-2/uso terapéutico , Trastuzumab/farmacología , Trastuzumab/uso terapéutico
7.
Int J Androl ; 34(6 Pt 2): e594-600, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21675994

RESUMEN

Optimal nutritional and hormonal statuses are determinants of successful ageing. The age associated decline in anabolic hormones such as testosterone and insulin-like growth factor 1 (IGF-1) is a strong predictor of metabolic syndrome, diabetes and mortality in older men. Studies have shown that magnesium intake affects the secretion of total IGF-1 and increase testosterone bioactivity. This observation suggests that magnesium can be a modulator of the anabolic/catabolic equilibrium disrupted in the elderly people. However, the relationship between magnesium and anabolic hormones in men has not been investigated. We evaluated 399 ≥65-year-old men of CHIANTI in a study population representative of two municipalities of Tuscany (Italy) with complete data on testosterone, total IGF-1, sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS) and serum magnesium levels. Linear regression models were used to test the relationship between magnesium and testosterone and IGF-1. Mean age of the population was 74.18 ± 6.43 (years ± SD, age range 65.2-92.4). After adjusting for age, magnesium was positively associated with total testosterone (ß ± SE, 34.9 ± 10.3; p = 0.001) and with total IGF-1 (ß ± SE, 15.9 ± 4.8; p = 0.001). After further adjustment for body mass index (BMI), log (IL-6), log (DHEAS), log (SHBG), log (insulin), total IGF-1, grip strength, Parkinson's disease and chronic heart failure, the relationship between magnesium and total testosterone remained strong and highly significant (ß ± SE, 48.72 ± 12.61; p = 0.001). In the multivariate analysis adjusted for age, BMI, log (IL-6), liver function, energy intake, log (insulin), log (DHEAS), selenium, magnesium levels were also still significantly associated with IGF-1 (ß ± SE, 16.43 ± 4.90; p = 0.001) and remained significant after adjusting for total testosterone (ß ± SE, 14.4 ± 4.9; p = 0.01). In a cohort of older men, magnesium levels are strongly and independently associated with the anabolic hormones testosterone and IGF-1.


Asunto(s)
Anabolizantes/sangre , Hormonas Esteroides Gonadales/sangre , Magnesio/sangre , Anciano , Humanos , Italia , Masculino
8.
Int J Immunopathol Pharmacol ; 24(2): 529-34, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21658330

RESUMEN

Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by a progressive cognitive and memory decline. Among peripheral markers of AD, great interest has been focused on the amyloid precursor protein (APP). In this regard, platelets represent an important peripheral source of APP since it has been demonstrated that the three major isoforms, that are constituted of 770, 751 and 695 aa residues, are inserted in the membrane of resting platelets. APP 751 and APP 770 contain a Kunitz-type serine protease inhibitor domain (APP KPI) and APP 695 lacks this domain. To address this issue, we first examined the platelet APP isoform mRNAs prospectively as biomarker for the diagnosis of AD by means of real-time quantitative PCR, and then evaluated the correlation between APP mRNA expression levels and cognitive impairment of enrolled subjects. Differential gene expression measurements in the AD patient group (n=18) revealed a significant up-regulation of APP TOT (1.52-fold), APP KPI (1.32-fold), APP 770 (1.33-fold) and APP 751 (1.26-fold) compared to controls (n=22). Moreover, a statistically significant positive correlation was found between APP mRNA levels (TOT, KPI, 770 and 751) and cognitive impairment. Since AD definitive diagnosis still relies on pathological evaluation at autopsy, the present results are consistent with the hypothesis that platelet APP could be considered a potential reliable peripheral marker for studying AD and could contribute to define a signature for the presence of AD pathology.


Asunto(s)
Enfermedad de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Plaquetas/química , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/fisiopatología , Biomarcadores/sangre , Estudios de Casos y Controles , Cognición , Femenino , Humanos , Italia , Masculino , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , ARN Mensajero/sangre , Regulación hacia Arriba
9.
Drugs Today (Barc) ; 57(9): 551-558, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34586103

RESUMEN

Up to 20% of breast cancers overexpress HER2, a molecular alteration conferring these tumors a particularly aggressive behavior. However, targeting HER2 has radically changed the prognosis of this disease in the last 2 decades, with multiple anti-HER2 compounds shown to improve disease outcomes both in the early and advanced setting. The latest anti-HER2 compound to be approved by the U.S. Food and Drug Administration (FDA) was margetuximab, an Fc-engineered monoclonal antibody with an improved binding to FcγRIIIA receptor, which leads to a greater antibody-dependent cellular cytotoxicity (ADCC) activation compared with trastuzumab. Margetuximab was shown to slightly improve progression-free survival compared with trastuzumab when combined with chemotherapy for the treatment of advanced HER2-positive breast cancer patients, and is now included among the available treatment options for pretreated HER2-positive breast cancer patients. In this monograph we recapitulate the clinical development, current role and future perspectives of margetuximab for the treatment of breast cancer.


Asunto(s)
Neoplasias de la Mama , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Humanos , Receptor ErbB-2 , Trastuzumab
10.
Phys Med ; 72: 96-102, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32247965

RESUMEN

This paper provides a first insight of the potential of the ß- Radio Guided Surgery (ß--RGS) in a complex surgical environment like the abdomen, where multiple sources of background concur to the signal at the tumor site. This case is well reproduced by ex-vivo samples of 90Y-marked Gastro-Entero-Pancreatic Neuroendocrine Tumors (GEP NET) in the bowel. These specimens indeed include at least three wide independent sources of background associated to three anatomical districts (mesentery, intestine, mucose). The study is based on the analysis of 37 lesions found on 5 samples belonging to 5 different patients. We show that the use of electrons, a short range particle, instead of γ particles, allows to limit counts read on a lesion to the sum of the tumor signal plus the background generated by the sole hosting district.The background on adjacent districts in the same specimen/patient is found to differ up to a factor 4, showing how the specificity and sensitivity of the ß--RGS technique can be fully exploited only upon a correct measurement of the contributing background. This locality has been used to set a site-specific cut-off algorithm to discriminate tumor and healthy tissue with a specificity of 100% and a sensitivity, on this test data sample, close to 100%. Factors influencing the sensitivity are also discussed. One of the specimens set allowed us evaluate the volume of the lesions, thus concluding that the probe was able to detect lesions as small as 0.04 mL in that particular case.


Asunto(s)
Partículas beta/uso terapéutico , Tumores Neuroendocrinos/cirugía , Cirugía Asistida por Computador/métodos , Algoritmos , Humanos
11.
Appl Radiat Isot ; 165: 109347, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32938536

RESUMEN

Radioguided surgery (RGS) is a medical practice which thanks to a radiopharmaceutical tracer and a probe allows the surgeon to identify tumor residuals up to a millimetric resolution in real-time. The employment of ß- emitters, instead of γ or ß+, reduces background from healthy tissues, administered activity to the patient, and medical exposure. In a previous work the possibility of using a CMOS Imager (Aptina MT9V011), initially designed for visible light imaging, to detect ß- from 90Y or 90Sr sources has been established. Because of its possible application as counting probe in RGS, the performances of MT9V011 in clinical-like conditions were studied.1 Through horizontal scans on a collimated 90Sr source of different sizes (1, 3, 5, 7 mm), we have determined relationships between scan fit parameters and the source dimension, namely A quadratic correlation and a linear dependency of, respectively, signal integrated over scan interval, and maximum signal against source diameter, are determined. Horizontal scan measurements on a source, interposing collimators of different size, aim to determine relationships or correlations between scan fit parameters and source dimension. A quadratic correlation and a linear dependency of, respectively, signal integrated over scan interval, and maximum signal against source diameter are determined. In order to get closer to clinical conditions, agar-agar phantoms containing 90Y with different dimensions and activities were prepared. A 90Y phantom is characterized by a central spot and a ring all around, for simulating both signal (tumor) and background (surrounding healthy tissue). The relationship found between scan maximum and 90Sr source diameter is then exploited to extract the concentration ratio between spot and external ring of the 90Y phantom. This observable, defined as the ratio between the tumor and the nearby healthy tissues uptake simulates the Tumor-to-Non-tumor Ratio (TNR). With the aim of evaluating the sensor's ability to discriminate signal from background relying on the significance parameter, a further 90Y phantom, featuring a well-known and clinical-like activity will mimic the signal only condition. This result is used to extrapolate to different source sizes, after having estimated the background for various TNR. The obtained significance values suggest that the MT9V011 sensor is capable of distinguishing a signal from an estimated background, depending on the interplay among TNR, acquisition time and tumor diameter.


Asunto(s)
Partículas beta , Neoplasias/cirugía , Radiofármacos/química , Cirugía Asistida por Computador/métodos , Estudios de Factibilidad , Humanos
12.
Phys Med ; 67: 85-90, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31704391

RESUMEN

PURPOSE: Radio Guided Surgery (RGS) is a technique that helps the surgeon to achieve an as complete as possible tumor resection, thanks to the intraoperative detection of particles emitted by a radio tracer that bounds to tumoral cells. In the last years, a novel approach to this technique has been proposed that, exploiting ß- emitting radio tracers, overtakes some limitations of established γ-RGS. In this context, a first prototype of an intraoperative ß particle detector, based on a high light yield and low density organic scintillator, has been developed and characterised on pure ß- emitters, like 90Y. The demonstrated very high efficiency to ß- particles, together with the remarkable transparency to photons, suggested the possibility to use this detector also with ß+ emitting sources, that have plenty of applications in nuclear medicine. In this paper, we present upgrades and optimisations performed to the detector to reveal such particles. METHODS: Laboratory measurement have been performed on liquid Ga68 source, and were used to validate and tune a Monte Carlo simulation. RESULTS: The upgraded detector has an ~80% efficiency to electrons above ~110keV, reaching a plateau value of ~95%. At the same time, the probe is substantially transparent to photons below ~200keV, reaching a plateau value of ~3%. CONCLUSIONS: The new prototype seems to have promising characteristics to perform RGS also with ß+ emitting isotopes.


Asunto(s)
Partículas beta , Electrones , Medicina Nuclear , Conteo por Cintilación , Cirugía Asistida por Computador
13.
Phys Med ; 58: 114-120, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30824142

RESUMEN

PURPOSE: Radio-guided surgery with ß- decays is a novel technique under investigation. One of the main advantages is its capability to detect small (⩽0.1 ml) samples after injecting the patient with low activity of radiopharmaceutical. This paper presents an experimental method to quantify this feature based on ex-vivo tests on specimens from meningioma patients. METHODS: Patients were enrolled on the basis of the standard uptake value (SUV) and the tumour-to-non-tumour activity ratio (TNR) resulted from 68Ga-DOTATOC PET exams. After injecting the patients with 93-167 MBq of 90Y-DOTATOC, 26 samples excised during surgery were analyzed with a ß- probe. The radioactivity expected on the neoplastic specimens was estimated according to the SUV found in the PET scan and the correlation with the measured counts was studied. The doses to surgeon and medical personnel were also evaluated. RESULTS: Even injecting as low as 1.4 MBq/kg of radiotracer, tumour residuals of 0.1 ml can be detected. A negligible dose to the medical personnel was confirmed. CONCLUSIONS: Radio-guided surgery with ß- decays is a feasible technique with a low radiation dose for both personnel and patient, in particular if the patient is injected with the minimum required activity. A correlation greater than 80% was observed between the measured counts and the expected activity for the lesion samples based on the individual SUV and the TNR. This makes identifiable the minimum injectable radiotracer activity for cases where 90Y is the utilized radionuclide.


Asunto(s)
Partículas beta , Tomografía de Emisión de Positrones , Cirugía Asistida por Computador/métodos , Radioisótopos de Itrio/administración & dosificación , Humanos , Inyecciones , Meningioma/diagnóstico por imagen , Meningioma/cirugía , Exposición Profesional/análisis , Octreótido/administración & dosificación , Octreótido/análogos & derivados , Dosis de Radiación
14.
Comput Biol Med ; 103: 140-147, 2018 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-30368170

RESUMEN

Thoracic endovascular aortic repair of the ascending aorta is becoming an option for patients considered unfit for open surgery. Such an endovascular procedure requires careful pre-operative planning and the customization of prosthesis design. The patient-specific tailoring of the procedure may call for dedicated tools to investigate virtual treatment scenarios. Given such considerations, the present study shows a computational framework for choosing and deploying stent-grafts via Finite Element Analysis, by supporting the device sizing and selection in a real case dealing with the endovascular treatment of a pseudoaneurysm. In particular, three devices with various lengths and materials were examined. Two off-the-shelf devices were computationally tested: one composed of Stainless Steel rings with a nominal length of 60 mm and another one with Nitinol rings and a distal free flow extension, with a nominal length of 70 mm. In third place, a custom-made stent-graft, also with Nitinol rings and containing both proximal and distal bare extensions with a nominal length of 75 mm, was deployed. The latter solution based on patient morphology and virtually benchmarked in this simulation framework, enhanced the apposition to the wall by reducing the distance between the skirt and the vessel from more than 6 mm to less than 2 mm in the distal sealing zone. Our experience shows that in-silico simulations can help choosing the right endograft for the ascending aorta as well as the right deployment sequence. This process may also encourage vendors to develop new devices for cases where open repair is unfeasible.


Asunto(s)
Aorta/cirugía , Implantación de Prótesis Vascular/instrumentación , Prótesis Vascular , Procedimientos Endovasculares/instrumentación , Modelación Específica para el Paciente , Anciano , Aneurisma Falso/diagnóstico por imagen , Aneurisma Falso/cirugía , Aorta/diagnóstico por imagen , Enfermedades de la Aorta/diagnóstico por imagen , Enfermedades de la Aorta/cirugía , Implantación de Prótesis Vascular/métodos , Procedimientos Endovasculares/métodos , Análisis de Elementos Finitos , Humanos , Masculino , Tomografía Computarizada por Rayos X
15.
Eur Phys J C Part Fields ; 78(11): 888, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30881205

RESUMEN

The CUPID-0 experiment searches for double beta decay using cryogenic calorimeters with double (heat and light) read-out. The detector, consisting of 24 ZnSe crystals 95 % enriched in 82 Se and two natural ZnSe crystals, started data-taking in 2017 at Laboratori Nazionali del Gran Sasso. We present the search for the neutrino-less double beta decay of 82 Se into the 0 1 + , 2 1 + and 2 2 + excited states of 82 Kr with an exposure of 5.74 kg · yr (2.24 × 10 25  emitters · yr). We found no evidence of the decays and set the most stringent limits on the widths of these processes: Γ ( 82 Se → 82 Kr 0 1 + )8.55 × 10 - 24  yr - 1 , Γ ( 82 Se → 82 Kr 2 1 + ) < 6.25 × 10 - 24  yr - 1 , Γ ( 82 Se → 82 Kr 2 2 + )8.25 × 10 - 24  yr - 1 (90 % credible interval).

16.
Eur Phys J C Part Fields ; 78(9): 734, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30839752

RESUMEN

The suppression of spurious events in the region of interest for neutrinoless double beta decay will play a major role in next generation experiments. The background of detectors based on the technology of cryogenic calorimeters is expected to be dominated by α particles, that could be disentangled from double beta decay signals by exploiting the difference in the emission of the scintillation light. CUPID-0, an array of enriched Zn 82 Se scintillating calorimeters, is the first large mass demonstrator of this technology. The detector started data-taking in 2017 at the Laboratori Nazionali del Gran Sasso with the aim of proving that dual read-out of light and heat allows for an efficient suppression of the α background. In this paper we describe the software tools we developed for the analysis of scintillating calorimeters and we demonstrate that this technology allows to reach an unprecedented background for cryogenic calorimeters.

17.
Eur Phys J C Part Fields ; 78(5): 428, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30996670

RESUMEN

The CUPID-0 detector hosted at the Laboratori Nazionali del Gran Sasso, Italy, is the first large array of enriched scintillating cryogenic detectors for the investigation of 82 Se neutrinoless double-beta decay ( 0 ν ß ß ). CUPID-0 aims at measuring a background index in the region of interest (RoI) for 0 ν ß ß at the level of 10 - 3  counts/(keV kg years), the lowest value ever measured using cryogenic detectors. CUPID-0 operates an array of Zn 82 Se scintillating bolometers coupled with bolometric light detectors, with a state of the art technology for background suppression and thorough protocols and procedures for the detector preparation and construction. In this paper, the different phases of the detector design and construction will be presented, from the material selection (for the absorber production) to the new and innovative detector structure. The successful construction of the detector lead to promising preliminary detector performance which is discussed here.

18.
J Biomech ; 49(12): 2513-9, 2016 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-26748728

RESUMEN

Prosthesis positioning in transcatheter aortic valve implantation procedures represents a crucial aspect for procedure success as demonstrated by many recent studies on this topic. Possible complications, device performance, and, consequently, also long-term durability are highly affected by the adopted prosthesis placement strategy. In the present work, we develop a computational finite element model able to predict device-specific and patient-specific replacement procedure outcomes, which may help medical operators to plan and choose the optimal implantation strategy. We focus in particular on the effects of prosthesis implantation depth and release angle. We start from a real clinical case undergoing Corevalve self-expanding device implantation. Our study confirms the crucial role of positioning in determining valve anchoring, replacement failure due to intra or para-valvular regurgitation, and post-operative device deformation.


Asunto(s)
Modelación Específica para el Paciente , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Anciano , Estenosis de la Válvula Aórtica/cirugía , Análisis de Elementos Finitos , Humanos , Masculino , Periodo Posoperatorio , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Reemplazo de la Válvula Aórtica Transcatéter/instrumentación , Resultado del Tratamiento
19.
Phys Med ; 32(9): 1139-44, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27601248

RESUMEN

PURPOSE: A radio-guided surgery technique with ß(-)-emitting radio-tracers was suggested to overcome the effect of the large penetration of γ radiation. The feasibility studies in the case of brain tumors and abdominal neuro-endocrine tumors were based on simulations starting from PET images with several underlying assumptions. This paper reports, as proof-of-principle of this technique, an ex vivo test on a meningioma patient. This test allowed to validate the whole chain, from the evaluation of the SUV of the tumor, to the assumptions on the bio-distribution and the signal detection. METHODS: A patient affected by meningioma was administered 300MBq of (90)Y-DOTATOC. Several samples extracted from the meningioma and the nearby Dura Mater were analyzed with a ß(-) probe designed specifically for this radio-guided surgery technique. The observed signals were compared both with the evaluation from the histology and with the Monte Carlo simulation. RESULTS: we obtained a large signal on the bulk tumor (105cps) and a significant signal on residuals of ∼0.2ml (28cps). We also show that simulations predict correctly the observed yields and this allows us to estimate that the healthy tissues would return negligible signals (≈1cps). This test also demonstrated that the exposure of the medical staff is negligible and that among the biological wastes only urine has a significant activity. CONCLUSIONS: This proof-of-principle test on a patient assessed that the technique is feasible with negligible background to medical personnel and confirmed that the expectations obtained with Monte Carlo simulations starting from diagnostic PET images are correct.


Asunto(s)
Neoplasias Encefálicas/radioterapia , Meningioma/radioterapia , Tomografía de Emisión de Positrones , Radiocirugia/métodos , Cirugía Asistida por Computador/métodos , Anciano , Algoritmos , Partículas beta , Neoplasias Encefálicas/diagnóstico por imagen , Simulación por Computador , Estudios de Factibilidad , Femenino , Humanos , Meningioma/diagnóstico por imagen , Modelos Teóricos , Método de Montecarlo , Exposición Profesional/prevención & control , Octreótido/análogos & derivados , Octreótido/química , Radiometría , Reproducibilidad de los Resultados
20.
Eur Phys J C Part Fields ; 76(7): 364, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28280442

RESUMEN

The R&D activity performed during the last years proved the potential of ZnSe scintillating bolometers to the search for neutrino-less double beta decay, motivating the realization of the first large-mass experiment based on this technology: CUPID-0. The isotopic enrichment in [Formula: see text]Se, the Zn[Formula: see text]Se crystals growth, as well as the light detectors production have been accomplished, and the experiment is now in construction at Laboratori Nazionali del Gran Sasso (Italy). In this paper we present the results obtained testing the first three Zn[Formula: see text]Se crystals operated as scintillating bolometers, and we prove that their performance in terms of energy resolution, background rejection capability and intrinsic radio-purity complies with the requirements of CUPID-0.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA