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1.
Int J Environ Sci Technol (Tehran) ; 19(11): 11531-11538, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34777529

RESUMO

Currently, the world is facing a horrible situation due to SARS-CoV-2. Though its RNA was found in wastewater, there are still no studies on RNA contamination detected in sewage. Hence, a possible treatment of sewage is suggested in this work. The disinfection stage is extremely important in the treatment of effluents, minimizing the impacts on the receiving body of water and promoting public health. In this context, the sequential use of ultrasound and ultraviolet radiation, on a bench scale, was investigated as a way to improve the disinfection of anaerobically treated effluents. Two types of treated effluents were tested, by septic tank and anaerobic filter, for which, two ultrasound frequencies, 25 and 40 kHz, and four doses of UV, 3.6; 9.0; 18 and 36 mJ cm-2 were applied. Physicochemical and microbiological parameters were observed for individual and sequential assays. The better quality of the anaerobic filter effluent influenced the performance of both processes, decreasing the concentration of organic load and turbidity, even though a concentration of total coliforms and Escherichia coli occurred in the lowest quality effluent (septic tank). The application of ultrasound has a positive effect on the inactivation of total coliforms and E. coli up to 1.0 log and provides better conditions for ultraviolet radiation to be sequentially applied. The UV radiation applied for the septic tank and the anaerobic filter inactivates 2.5 log for total coliforms and 3.5 log for E. coli, respectively. It is suggested that the disinfection methods applied in this work to inactivate gram-negative bacteria (E. coli) can also be applied to secondary treatment effluents, as well as being better tested for viruses, protozoa, and helminths. Supplementary Information: The online version contains supplementary material available at 10.1007/s13762-021-03764-7.

3.
Crit Rev Oncol Hematol ; 133: 17-24, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30661653

RESUMO

Pancreatic ductal adenocarcinoma is one of the leading causes of cancer-related deaths and, currently, surgery is the only curative treatment. Patients with borderline resectable pancreatic cancer (BRPC) can benefit from a multidisciplinary approach and R0 resection, and can achieve the same outcome as resectable patients treated with upfront surgery. However, the definition of BRPC changes according to different classifications with a heterogeneous distribution of patients, and it is thus difficult to compare clinical evidence. We performed a literature review to assess the most suitable classification of BRPC. Our review was conducted using the PubMed database. Only articles containing more than ten patients classified according to NCCN, MDACC or AHPBA/SSAT/SSO classifications were selected. A total of 16 studies were included in our analysis, and were grouped according to one of these three classifications. The total resection rate was 61.4%, with considerable differences between the groups (68.4% for NCCN, 54.9% for MDACC and 53.2% for AHPBA/SSO/SSAT). The total R0 resection rate was 90.1% (89.1% for NCCN, 92.5% for MDACC and 84% for AHPBA/SSO/SSAT). Of the three classifications, NCCN limits the use of confusing terms and uses restrictive criteria to define the most appropriate treatment for each subgroup. However, several reports have suggested that, even in the case of a limited disease, biological and clinical factors should be considered in order to classify patients as resectable. NCCN classification appears to be the classification that allows the highest percentage of patients with BRPC to achieve resection without reducing the R0 resection rate. The choice of therapy should not only be based on imaging results, but also on a wider clinical multidisciplinary evaluation.


Assuntos
Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/cirurgia , Pancreatectomia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/cirurgia , Adenocarcinoma/classificação , Adenocarcinoma/diagnóstico , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Carcinoma Ductal Pancreático/classificação , Carcinoma Ductal Pancreático/patologia , Comportamento de Escolha , Humanos , Pancreatectomia/métodos , Neoplasias Pancreáticas/classificação , Neoplasias Pancreáticas/patologia , Seleção de Pacientes , Prognóstico , Resultado do Tratamento
4.
J Surg Case Rep ; 2018(2): rjy012, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29479415

RESUMO

Pancreatic metastases are rare, <2% of all pancreatic neoplasia. This is the first case of pancreatic metastasis from adamantinoma, a rare, low grade and slow growing tumor which is frequently localized in long bones. We describe a case of a 45-year-old woman presenting with increased bilirubin level. Computed tomography and ecoendoscopic ultra sonography revealed a pancreatic head mass. Fine-needle aspiration biopsy was consistent with metastatic adamantinoma. The patient was submitted to a standard pancreaticoduodenectomy. As in the case presented, standard pancreatic resections are safe and feasible options to treat non-pancreatic primary tumor improving patient's survival and quality of life.

5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2017: 4529-4532, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29060904

RESUMO

Laser Ablation (LA) is a minimally invasive technique for tumor removal. The laser light is guided into the target tissue by a fiber optic applicator; thus the physical features of the applicator tip strongly influence size and shape of the tissue lesion. This study aims to verify the geometry of the lesion achieved by a tapered-tip applicator, and to investigate the percentage of thermally damaged cells induced by the tapered-tip fiber optic applicator. A theoretical model was implemented to simulate: i) the distribution of laser light fluence rate in the tissue through Monte Carlo method, ii) the induced temperature distribution, by means of the Bio Heat Equation, iii) the tissue injury, by Arrhenius integral. The results obtained by the implementation of the theoretical model were experimentally assessed. Ex vivo porcine liver underwent LA with tapered-tip applicator, at different laser settings (laser power of 1 W and 1.7 W, deposited energy equal to 330 J and 500 J, respectively). Almost spherical volume lesions were produced. The thermal damage was assessed by measuring the diameter of the circular-shaped lesion. The comparison between experimental results and theoretical prediction shows that the thermal damage discriminated by visual inspection always corresponds to a percentage of damaged cells of 96%. A tapered-tip applicator allows obtaining localized and reproducible damage close to spherical shape, whose diameter is related to the laser settings, and the simple theoretical model described is suitable to predict the effects, in terms of thermal damage, on ex vivo liver. Further trials should be addressed to adapt the model also on in vivo tissue, aiming to develop a tool useful to support the physician in clinical application of LA.


Assuntos
Tecnologia de Fibra Óptica , Animais , Hipertermia Induzida , Terapia a Laser , Lasers , Modelos Teóricos , Suínos
6.
Crit Rev Oncol Hematol ; 104: 9-20, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27286698

RESUMO

Malignant Pleural Mesothelioma (MPM) remains a relevant public health issue, and asbestos exposure is the most relevant risk factor. The incidence has considerably and constantly increased over the past two decades in the industrialized countries and is expected to peak in 2020-2025. In Italy, a standardized-rate incidence in 2011 among men was 3.5 and 1.25 per 100,000 in men and women, respectively, and wide differences are noted among different geographic areas. The disease remains challenging in terms of diagnosis, staging and treatment and an optimal strategy has not yet been clearly defined. The Third Italian Multidisciplinary Consensus Conference on Malignant Pleural Mesothelioma was held in Bari (Italy) in January 30-31, 2015. This Consensus has provided updated recommendations on the MPM management for health institutions, clinicians and patients.


Assuntos
Neoplasias Pulmonares , Mesotelioma , Neoplasias Pleurais , Animais , Humanos , Incidência , Itália/epidemiologia , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/terapia , Mesotelioma/complicações , Mesotelioma/diagnóstico , Mesotelioma/epidemiologia , Mesotelioma/terapia , Mesotelioma Maligno , Derrame Pleural/etiologia , Neoplasias Pleurais/complicações , Neoplasias Pleurais/diagnóstico , Neoplasias Pleurais/epidemiologia , Neoplasias Pleurais/terapia , Saúde Pública , Fatores de Risco
7.
Int J Surg ; 31: 93-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27267949

RESUMO

BACKGROUND: Pancreaticoduodenectomy is still associated to high morbility, especially due to pancreatic surgery related and infectious complications: many risk factors have already been advocated. Aim of this study is to evaluate the role of preoperative oral immunonutrition in well nourished patients scheduled for pancreaticoduodenectomy. METHODS: From February 2014 to June 2015, 54 well nourished patients undergoing pancreaticoduodenectomy were enrolled for 5 days preoperative oral immunonutrition. A series of consecutive patients submitted to the same intervention in the same department, with preoperative standard oral diet, was matched 1:1. For analysis demographic, pathological and surgical variables were considered. Mortality rate, overall postoperative morbility, pancreatic fistula, post pancreatectomy haemorrhage, delayed gastric emptying, infectious complications and length of hospital stay were described for each groups. Chi squared test, Fisher's Exact test and Student's T test were used for comparison. Differences were considered statistically significant at p < 0.05. Statistics was performed using a freeware Microsoft Excel (®) based program and SPSS v 10.00. RESULTS: No statistical differences in term of mortality (2.1% in each groups) and overall morbility rate (41.6% vs 47.9%) occurred between the groups as well as for pancreatic surgery related complications. Conversely, statistical differences were found for infectious complications (22.9% vs 43.7%, p = 0.034) and length of hospital stay (18.3 ± 6.8 days vs 21.7 ± 8.3, p = 0.035) in immunonutrition group. CONCLUSION: Preoperative oral immunonutrition is effective for well nourished patients scheduled for pancreaticoduodenectomy; it helps to reduce the risk of postoperative infectious complications and length of hospital stays.


Assuntos
Neoplasias do Ducto Colédoco/dietoterapia , Neoplasias do Ducto Colédoco/cirurgia , Pancreatopatias/dietoterapia , Pancreatopatias/cirurgia , Pancreaticoduodenectomia/efeitos adversos , Cuidados Pré-Operatórios , Idoso , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Fatores de Risco
8.
Med Lav ; 106(5): 325-32, 2015 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-26384258

RESUMO

The III Italian Consensus Conference on Pleural Mesothelioma (MM) convened on January 29th 2015. This report presents the conclusions of the 'Epidemiology, Public Health and Occupational Medicine' section. MM incidence in 2011 in Italy was 3.64 per 100,000 person/years in men and 1.32 in women. Incidence trends are starting to level off. Ten percent of cases are due to non-occupational exposure. Incidence among women is very high in Italy, because of both non-occupational and occupational exposure. The removal of asbestos in place is proceeding slowly, with remaining exposure. Recent literature confirms the causal role of chrysotile. Fibrous fluoro-edenite was classified as carcinogenic by IARC (Group 1) on the basis of MM data. A specific type (MWCNT-7) of Carbon Nanotubes was classified 2B. For pleural MM, after about 45 years since first exposure, the incidence trend slowed down; with more studies needed. Cumulative exposure is a proxy of the relevant exposure, but does not allow to distinguish if duration or intensity may possibly play a prominent role, neither to evaluate the temporal sequence of exposures. Studies showed that duration and intensity are independent determinants of MM. Blood related MM are less than 2.5%. The role of BAP1 germline mutations is limited to the BAP1 cancer syndrome, but negligible for sporadic cases. Correct MM diagnosis is baseline; guidelines agree on the importance of the tumor gross appearance and of the hematoxylin-eosin-based histology. Immunohistochemical markers contribute to diagnostic confirmation: the selection depends on morphology, location, and differential diagnosis. The WG suggested that 1) General Cancer Registries and ReNaM Regional Operational Centres (COR) interact and systematically compare MM cases; 2) ReNaM should report results presenting the diagnostic certainty codes and the diagnostic basis, separately; 3) General Cancer Registries and COR should interact with pathologists to assure the up-to-date methodology; 4) Necroscopy should be practiced for validation. Expert referral centres could contribute to the definition of uncertain cases. Health surveillance should aim to all asbestos effects. No diagnostic test is recommended for MM screening. Health surveillance should provide information on risks, medical perspective, and smoking cessation. The economic burden associated to MM was estimated in 250,000 Euro per case.


Assuntos
Neoplasias Pulmonares , Mesotelioma , Doenças Profissionais , Neoplasias Pleurais , Amianto/efeitos adversos , Humanos , Itália , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/etiologia , Mesotelioma/epidemiologia , Mesotelioma/etiologia , Mesotelioma Maligno , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Medicina do Trabalho , Neoplasias Pleurais/epidemiologia , Neoplasias Pleurais/etiologia , Saúde Pública
9.
Med Eng Phys ; 37(7): 631-41, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25979670

RESUMO

Laser Ablation (LA) is a minimally-invasive procedure for tumor treatment. LA outcomes depend on the heat distribution inside tissues and require accurate temperature measurement during the procedure. Magnetic resonance imaging (MRI) allows a non-invasive and three-dimensional thermometry of the organ undergoing LA. In this study, the temperature distribution within two swine pancreases and three swine livers undergoing LA (Nd:YAG, power: 2 W, treatment time: 4 min) was monitored by a 1.5-T MR scanner, utilizing two T1-weighted sequences (IRTF and SRTF). The signal intensity in four regions of interest, placed at different distances from the laser applicator, was related to temperature variations monitored in the same regions by twelve fiber Bragg grating sensors. The relationship between the signal intensity and temperature increase was calculated to obtain the calibration curve and to evaluate accuracy, sensibility and precision of each sequence. This is the first study of MR-based thermometry during LA on pancreas. More specifically, the IRTF sequence provides the highest temperature sensitivity in both liver (1.8 ± 0.2 °C(-1)) and pancreas (1.8 ± 0.5 °C(-1)) and the lowest precision and accuracy. SRTF sequence on pancreas presents the highest accuracy and precision (MODSFRT = -0.1 °C and LOASFRT = [-2.3; 2.1] °C).


Assuntos
Terapia a Laser/métodos , Fígado/cirurgia , Imagem por Ressonância Magnética Intervencionista/métodos , Pâncreas/cirurgia , Termometria/métodos , Animais , Calibragem , Terapia a Laser/instrumentação , Lasers , Modelos Lineares , Fígado/anatomia & histologia , Fígado/fisiologia , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/métodos , Imagem por Ressonância Magnética Intervencionista/instrumentação , Pâncreas/anatomia & histologia , Pâncreas/fisiologia , Suínos , Temperatura , Termometria/instrumentação
10.
Minerva Chir ; 70(3): 175-80, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25960031

RESUMO

AIM: Distal pancreatectomies (DP) are associated with high risk of postoperative complications, and in many series higher morbidity rate than duodenopancreatectomies has been reported. To evaluate the role of a collagen sponge with human fibrinogen and thrombin film (TachoSil®) in limiting the incidence of complications after DP. METHODS: From 1996 to 2013, 221 patients have been submitted to distal pancreatectomy (± splenectomy) in our Division. A retrospective analysis has been conducted in a group of 36 consecutive and prospectively collected DP treated with intraoperative placement of TachoSil® on pancreatic stump from 2010 to 2013 (group 1). A control series of 36 consecutive patients (group 2) was matched 1:1 from hystorical database. The variables considered in the analysis were: age, gender, ASA score, pancreatic texture (hard vs. soft), histology, operative time, postoperative mortality, morbility (postoperative pancreatic fistula - POPF, postoperative hemorrage - PPH, delayed gastric emptying - DGE) and hospital stay. Differences between POPF, PPH, DGE and hospital stays between grops were investigated with χ² and t-Student test. Univariate analysis was conducted to determine factors related to POPF development. Statistical analysis was performed using freeware Microsoft Excel based program. RESULTS: Post operative mortality was 0% in both groups. POPF were registered in 36.1% (13/36) and 41.6 % (15/36) in groups 1 and 2, respectively (P=n.s.); in group 1 we didn't observe grade C POPF, while 4 patients in control group developed grade C POPF (P<0,05). No differences were found between two groups in terms of incidence of PPH and DGE. The median duration of postoperative hospital stay in group 1 was 21.8 (7-189) days compared with 31.13 (9-249) days in group 2 (P<0.001). CONCLUSION: The use of TachoSil® seems to be associated with lower incidence of grade C POPF but larger controlled trials are needed to surely assess the usefulness of TachoSil® in pancreatic surgery in order to reduce pancreatic specific complications and their severity.


Assuntos
Fibrinogênio/administração & dosagem , Pancreatectomia , Trombina/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Combinação de Medicamentos , Feminino , Humanos , Incidência , Itália/epidemiologia , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Pancreatectomia/efeitos adversos , Fístula Pancreática/prevenção & controle , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 1283-6, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26736502

RESUMO

Estimation of optical properties of biologic tissues is determinant for laser dosimetry in medical applications. Tissues highly absorb and scatter the light in near infrared spectrum, where the laser provides therapeutic effects. Novel frontiers of clinical practice, e.g., the employment of laser light for the treatment of pancreatic cancer, require information about pancreas-laser interaction, which are crucial for therapy management. The property of biological tissues to scatter the light traveling through is described by the anisotropy coefficient (g). The relationship between g and the angular distribution of the scattered light is described by Henyey-Greenstein phase function. The measurement of angular distribution of scattered light is performed by the goniometric technique. This paper describes the estimation of g of ex vivo pancreas at 1064 nm, performed by a goniometric-based system, where a photodetector measures intensities of scattered light at fixed angles between -120° and 120°. A two-term Henyey-Greenstein phase function has been employed to estimate anisotropy coefficient for forward (gfs) and backward scattering (gbs). Experimental trails were performed to assess the repeatability of measurement system: percentage value of standard deviation is generally lower than 8% for angles higher (lower) than 13° (13°). Measurements were performed for the first time on healthy swine pancreas, aiming to investigate the influence of coagulation temperature: gfs decreases from 0.94 (at 25 °C) to 0.93 (at 80 °C). Afterwards, the same set up has been employed for the estimation of g of human pancreas affected by neuroendocrine tumor, which presented an estimated values for gfs of 0.89.


Assuntos
Anisotropia , Animais , Humanos , Lasers , Luz , Pâncreas , Neoplasias Pancreáticas , Espalhamento de Radiação
13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 1287-90, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26736503

RESUMO

Temperature monitoring in tissue undergone Laser Ablation (LA) may be particularly beneficial to optimize treatment outcome. Among many techniques, fiber Bragg grating (FBG) sensors show valuable characteristics for temperature monitoring in this medical scenario: good sensitivity and accuracy, and immunity from electromagnetic interferences. Their main drawback is the sensitivity to strain, which can entail measurement error for respiratory and patient movements. The aims of this work are the design, the manufacturing and the characterization of a needle-like probe which houses 4 FBGs. Three FBGs have sensitive length of 1 mm and are used as temperature sensors; one FBG with length of 10 mm is used as reference and to sense eventual strain. The optical fiber housing the FBGs was encapsulated within a needle routinely used in clinical practice to perform MRI-guided biopsy. Two materials were used for the encapsulation: i) thermal paste for the 3 FBGs used for temperature monitoring, to maximize the thermal exchange with the needle; ii) epoxy resin for the reference FBG, to improve its sensitivity to strain. The static calibration of the needle-like probe was performed to estimate the thermal sensitivity of each FBG; the step response was investigated to estimate the response time. FBGs 1 mm long have thermal sensitivity of 0.01 nm·°C(-1), whereas the reference FBG presents 0.02 nm·°C(-1). For all FBGs, the response time was in the order of 100 ms. Lastly, experiments were performed on ex vivo swine liver undergoing LA to i) evaluate the possible presence of measurement artifact, due to the direct absorption of laser light by the needle and ii) assess the feasibility of the probe in a quasi clinical scenario.


Assuntos
Terapia a Laser , Animais , Espectroscopia de Ressonância Magnética , Agulhas , Fibras Ópticas , Suínos , Temperatura
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 1691-4, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26736602

RESUMO

Bronchial blockers (BBs) allow occluding the bronchial duct and collapsing the "dependent" lung in a number of thoracic surgery. The occlusion is obtained through a cuff that, inflated with a proper air volume, exerts a pressure, Pe, on the inner wall of the mainstem bronchus. In this work a measurement chain, based on two piezorestistive force sensors, was developed and calibrated to measure Pe exerted by six BBs, as a function of inflated volume on in vitro models (two latex ducts with diameters similar to the ones of the adult mainstem bronchi: 12 mm and 15 mm). Pe showed wide changes considering different BBs, and significantly increases with the decrease of the model's diameter, at the same inflated volume. Lastly, the minimum occlusive volume (MOV) to sail the two models was estimated for each BB. These experiments were performed by applying a pressure difference across the cuff of 25 cmH2O, in order to simulate the worst condition in a clinical scenario. Results show that MOV depends on both the type of BB and the duct diameter. The knowledge of this volume allows estimating the minimum value of Pe exerted by BBs to avoid air leakage.


Assuntos
Procedimentos Cirúrgicos Torácicos/instrumentação , Oclusão com Balão/instrumentação , Brônquios , Humanos , Pressão
15.
Med Lav ; 105(3): 187-96, 2014.
Artigo em Italiano | MEDLINE | ID: mdl-25078800

RESUMO

INTRODUCTION: In the period 1957/1995 more than 200,000 tons of asbestos arrived at the Port of Livorno. This paper attempts to reconstruct the levels of exposure of the dockers during this period, given the absence of any environmental investigations. METHODS: The estimates were calculated using the quantities unloaded annually, the number of dockers, the duration and frequency of the unloading operations, the type of packaging and the background pollution. The Time Weighted Average annual exposure allows calculation of a range of cumulative exposure for each worker with a known period of employment. The working methods were reconstructed interviewing employees and the levels of pollution used in the calculations were partly obtained from published data. RESULTS: Significant doses were accumulated by dockers who worked at the port in the 60's and 70's. Non-coincidence of the period with the highest imports with that of highest exposure is worth highlighting. Since 1980 the annual average exposure levels were well below the level required for granting insurance compensation benefits. This suggests caution in the use of lists of beneficiaries for epidemiological purposes since the statistical power would be very low. CONCLUSIONS: The strongest point of the research is the estimated annual TWA exposure that, regardless of the accuracy of the data, does however allow an epidemiological analysis of the cohort for subgroups with different exposure. The twenty-three cases of mesothelioma already recorded in this cohort were first employed before 1966. This method can be used to estimate exposure in other ports, where basic information is available.


Assuntos
Amianto/efeitos adversos , Exposição Ocupacional/efeitos adversos , Humanos , Itália , Exposição Ocupacional/estatística & dados numéricos , Navios , Fatores de Tempo
16.
Int J Hyperthermia ; 30(4): 219-27, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24964063

RESUMO

The dependence of computed tomography (CT) values on temperature has been pointed out by several authors since the late 1970s. They emphasised the importance of this phenomenon on the calibration process with water equivalent phantoms of the CT scanners. Few years later the potential of CT thermometry for non-invasive temperature mapping during thermal procedures was investigated. The interest on the employment of this technique during thermal treatments has been recently renewed with the improvement of modern CT scanner performances and with the increased popularity of minimally invasive thermal techniques for cancer treatment. A good thermometry allows avoiding unintended damage of the healthy tissues during the procedure by providing a detailed tissue temperature distribution; therefore, it is recommended in order to achieve good effectiveness of the thermal treatment. Researchers have been working on this issue for more than four decades and different non-invasive solutions have been proposed, i.e., microwave thermal imaging, infrared (IR)-, ultrasound-, magnetic-resonance (MR)-, and CT-based thermometry. This review aims to summarise the essential physics and the currently available data on CT-based thermometry and to elucidate the potential use of this technique during thermal procedures. Background information on measuring principle, an investigation of the performances achieved by this technique and the thermal sensitivity of the CT-number of different organs are provided and discussed.


Assuntos
Hipertermia Induzida/métodos , Termometria/métodos , Animais , Humanos , Temperatura , Termômetros , Tomografia Computadorizada por Raios X
17.
Artigo em Inglês | MEDLINE | ID: mdl-25571147

RESUMO

In hemochromatosis an abnormal accumulation of iron is present in parenchymal organs and especially in liver. Among the several techniques employed to diagnose the iron overload, magnetic resonance imaging (MRI) and Computed Tomography (CT) are the most promising non-invasive ones. MRI is largely used but shows limitation including an overestimation of iron and inability to quantify iron at very high concentrations. Therefore, some research groups are focusing on the estimation of iron concentration by CT images. Single X-ray CTs are not able to accurately perform this task in case of the presence of confounding factors (e.g., fat). A potential solution to overcome this concern is the employment of Dual-Energy CT (DECT). The aim of this work is to investigate influence of the kVp and mAs on CT number sensitivity to iron concentration. A phantom with test tubes filled with homogenized porcine liver at different iron concentrations, has been scanned with DECT at different mAs. The images have been analyzed using an ad-hoc developed algorithm which allows minimizing the influence of air bubbles present in the homogenized. Data show that the sensitivity is strongly influenced by kVp (its value almost halves from 80 kVp to 140 kVp; e.g. 0.41 g·µmol(-1) and 0.19 g·µmol(-1) at 80 kVp/120 mAs and 140 kVp/60 mAs respectively), on the other hand the influence of mAs value is negligible.


Assuntos
Ferro/metabolismo , Fígado/diagnóstico por imagem , Fígado/metabolismo , Tomografia Computadorizada por Raios X/métodos , Animais , Imagens de Fantasmas , Suínos , Raios X
18.
Artigo em Inglês | MEDLINE | ID: mdl-24110542

RESUMO

Thermal effects of different applicators for energy deposition in tissue undergoing laser interstitial thermotherapy (LITT) are investigated. The aim is to predict temperature distribution (T), dimensions and shape of thermal lesion produced by the laser light absorption within the tissue, in order to achieve an optimal design of the applicator for LITT. A numerical model, based on Monte Carlo method, was implemented to predict the distribution of laser light within the tissue, and the Bio Heat Equation was used to simulate T. Four geometries of optical applicators with different emitting surfaces were considered: bare fiber, cylindrical, zebra and a hybrid geometry. Effects on liver tissue undergoing LITT were evaluated in terms of T and coagulation volumes. Simulations were performed with laser power of 3 W and 5 W and energy of 1650 J. Results show that bare fiber causes an irregular coagulation shape; zebra and hybrid applicators 3 cm-long obtain an elliptical lesion, with lowest maximum T (Tmax) on their surface (about 350 K); cylindrical applicators with length of 1 cm or 1.5 cm produce spherical lesions, with Tmax up to 398 K. Results suggest that the selection of the applicator based on the geometry of the lesion could improve LITT outcome. Furthermore, an appropriate geometry can preserve applicator integrity avoiding excessive temperature increase on its surface.


Assuntos
Hipertermia Induzida/métodos , Lasers , Tecnologia de Fibra Óptica , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Modelos Teóricos , Método de Monte Carlo , Neoplasias/cirurgia , Neoplasias/terapia , Temperatura
19.
Artigo em Inglês | MEDLINE | ID: mdl-24110543

RESUMO

Temperature distribution T(x,y,z,t) in tissue undergoing Laser-induced Interstitial Thermotherapy (LITT) plays a crucial role on treatment outcome. Theoretical and experimental assessment of temperature on ex vivo laser-irradiated pancreas is presented. The aim of this work is to assess the influence of thermometers dimensions on temperature measures during LITT. T(x,y,z,t) inside tissue is monitored by optical sensors, i.e., Fiber Bragg Gratings (FBGs): three FBGs with lengths of 10 mm and nine FBGs of 1 mm, at different distances (2 mm, 5 mm and 10 mm) and different quotes (0 mm, 2 mm and 4 mm) from the laser fiber tip are used. Theoretical punctual T(x,y,z,t) is averaged out on both 10 mm and 1 mm in order to compare numerical predictions with experimental data. Results demonstrate the influence of FBG length on T(x,y,z,t) measures. This phenomenon depends on the distance between sensor and applicator: it is particularly significant close to the applicator tip (2 mm) because of the high spatial T(x,y,z,t) gradient within the tissue. Both theoretical results and experimental ones show that just at a distance of 10 mm from the tip, differences between T(x,y,z,t) provided by FBGs of 10 mm and 1 mm are negligible.


Assuntos
Hipertermia Induzida/métodos , Lasers , Algoritmos , Humanos , Hipertermia Induzida/instrumentação , Modelos Teóricos , Neoplasias Pancreáticas/terapia , Temperatura
20.
Artigo em Inglês | MEDLINE | ID: mdl-24109703

RESUMO

Laser interstitial thermotherapy (LITT) is a minimally invasive technique used to thermally destroy tumour cells. Being based on hyperthermia, LITT outcome depends on the temperature distribution inside the tissue. Recently, CT scan thermometry, based on the dependence of the CT number (HU) on tissue temperature (T) has been introduced during LITT; it is an attractive approach to monitor T because it overcomes the concerns related to the invasiveness. We performed LITT on nine ex vivo swine livers at three different laser powers, (P=1.5 W, P=3 W, P=5 W) with a constant treatment time t=200 s; HU is averaged on two ellipsoidal regions of interest (ROI) of 0.2 cm2, placed at two distances from the applicator (d=3.6 mm and d=8.7 mm); a reference ROI was placed away from the applicator (d=30 mm). The aim of this study is twofold: 1) to evaluate the effect of the T increase in terms of HU variation in ex vivo swine livers undergoing LITT; and 2) to estimate the P value for tissue vaporization. To the best of our knowledge, this is the first study focused on the HU variation in swine livers undergoing LITT at different P. The reported findings could be useful to assess the effect of LITT on the liver in terms of both T changes and tissue vaporization, with the aim to obtain an effective therapy.


Assuntos
Hipertermia Induzida/instrumentação , Neoplasias/terapia , Tomografia Computadorizada por Raios X/instrumentação , Animais , Desenho de Equipamento , Hipertermia Induzida/métodos , Terapia a Laser/instrumentação , Lasers , Fígado/patologia , Neoplasias/patologia , Imagens de Fantasmas , Reprodutibilidade dos Testes , Suínos , Temperatura , Termometria , Tomografia Computadorizada por Raios X/métodos , Volatilização
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