Dentre as técnicas diagnósticas por imagem, em Medicina Nuclear, têm-se destacado a Tomografia por Emissão de Pósitrons (PET). O PET fornece imagens funcionais da região ou órgão de interesse, possibilitanto o diagnóstico de várias doenças e, também, um mapeamento da evolução ou regressão das mesmas. Os atuais sistemas PET apresentam blocos de cristais arranjados em geometria circular, mas a busca por novos arranjos, em geometrias diferenciadas, é pertinente, pois pode possibilitar um melhor desempenho destes tomógrafos. O objetivo deste estudo é avaliar o desempenho de um sistema PET constituído por blocos de cristais em arranjo elipsoidal. Para tal estudo, fez-se uso do GATE, ambiente de simulação para tomografia por emissão que apresentou resultados satisfatórios comparados à aparelhos utilizados na rotina clínica. Desta forma, elaborou-se dois sistemas PET, o primeiro com 46 blocos de cristais arranjados em geometria circular, no qual, os detectores opostos foram separados a uma distância de 816,4 mm na direção transaxial. No segundo caso, utilizou-se 36 blocos de cristais, arranjados em geometria elíptica, onde os detectores foram separados a uma distância de 500 mm na direção vertical e 816,4 mm na direção horizontal. Uma vez realizadas as simulações, fez-se os testes de validação para Sensibilidade, Fração de Espalhamento, NEC (Noise Equivalente Count Rate) e Resolução Espacial, para então, avaliar e comparar o desempenho do sistema PET para ambas as geometrias propostas. Estes testes foram feitos de acordo com as especificações da norma NEMA NU 2-2007. Para o teste de sensibilidade, com o phantom localizado no centro do FOV transaxial do tomógrafo, obteve-se um ganho no sistema PET, com geometria elíptica, de 28,7% em relação ao sistema convencional, de geometria circular. Para o phantom deslocado à 10 cm do centro do FOV transaxial, a sensibilidade do sistema PET elíptico foi 26,2% superior em relação ao circular. O tempo de aquisição para cada simulação neste teste foi de 400 s. Para os testes de Fração de Espalhamento e NEC foram realizadas 33 simulações, para cada geometria, variando o tempo de aquisição e a atividade. A fração de espalhamento na geometria elíptica foi de 35,5% e na circular 34,6%. Na geometria circular, a curva NEC atinge o pico máximo em 259,3 kcps a uma concentração de atividade de 34,1 kBq ml-1 , já para geometria elíptica, o pico máximo é atingido em 239,1 kcps a uma concentração de atividade de 24,8 kBq ml-1 . As medidas foram adquiridas em três posições transaxiais (x,y) no centro do FOV e, posteriormente, deslocadas em ¼ do centro do FOV, totalizando 6 medidas para cada geometria. Para cada uma destas 6 medidas, encontrou-se a FWHM (largura a meia altura) e a FWTM (largura a 10% do máximo) nos 3 eixos de coordenadas (x,y,z), assim, para cada geometria proposta obteve-se 18 valores de FWHM e 18 valores de FWTM. A geometria elíptica apresentou melhoras na resolução espacial em FWHM em 4 dos 18 valores de resolução. Já para FWTM, a geometria elíptica apresentou melhora em 8 dos 18 valores de resolução. Em relação a FWHM, onde houve melhora na resolução espacial, teve-se um ganho médio de 18,7%. Já as perdas, em resolução espacial foi em média 43,26%. Para FWTM, a melhora em resolução espacial foi em média 12,09%, mas a perda de resolução, neste caso, foi em média 45,59%. Pode-se concluir que a geometria proposta apresenta algumas vantagens em relação a geometria convencional. Na geometria elíptica há uma redução de 10 blocos de cristais em relação a geometria circular, o que possivelmente gera uma redução no custo de fabricação do tomógrafo. Em relação a sensibilidade, há uma melhora significativa para nova geometria, bem como uma redução da concentração da atividade na qual o tomógrafo alcança seu melhor desempenho, embora ocorra uma ligeira diminuição na taxa de contagens no sistema elíptico. Essa redução na concentração de atividade pode ocasionar uma redução no tempo de exame e utilização de menos material radioativo, reduzindo o risco ao paciente e o custo do exame, bem como possibilitando a realização de um maior número de exames num mesmo intervalo de tempo. A fração de espalhamento do sistema elíptico é ligeiramente maior em relação ao sistema circular. A principal perda do sistema PET elíptico está na resolução espacial, onde não houve melhoras para maior parte das medidas realizadas, necessitando de alguns ajustes que pode se dar, entre outras coisas, no arranjo dos blocos de cristais. Acredita-se que ajustes na angulação dos detectores e na formação das coincidências seja possível melhorias nas resoluções, e NEC. / Among the diagnostic imaging techniques, in Nuclear Medicine, have been prominent in Positron Emission Tomography (PET). PET provides functional images of the region or organ of interest, allowing diagnostic of various diseases and also a mapping of the development or regression of the same. Current PET systems feature blocks arranged in circular geometry crystals, but the search for new arrangements, in different geometries, is relevant because it can provide a better performance of these scanners. The objective of this study is to evaluate the performance of a PET system consisting of blocks of crystals ellipsoidal arrangement. For this study, we used the GATE simulation environment for emission tomography that presented satisfactory results compared to the devices used in the clinical routine. This way we prepared two PET systems, the first one containing 46 blocks of crystals arranged in a circular geometry, where the opposite detectors were separated by a distance of 816.4 mm in the transaxial direction. In the second case, we used 36 blocks of crystals arranged in an elliptical geometry, where the detectors are separated a distance of 500 mm in the vertical direction and 816.4 mm in the horizontal direction. After the simulations were performed, the validation tests for sensitivity, scatter fraction, NEC (Noise Equivalent Count Rate) and Spatial Resolution were made, to finally evaluate and compare the performance of the PET system for both proposed geometries. The tests were made accordingly to specified NEMA NU 2-2007 standard. For the sensitivity test, with the phantom located in the center of FOV transaxial of the tomography, we obtained a gain in PET system with elliptical geometry of 28.7% compared to the conventional system, the circular geometry. For the phantom shifted to 10 cm from the center of the transaxial FOV, the sensitivity of PET elliptical system was 26.2% higher than in the circular. The acquisition time for each simulation in this test was 400 s. For Scatter Fraction test and NEC, were made 33 simulations for each geometry, varying the time of acquisition and activity. The scatter fraction in the elliptical geometry was 35,5% and 34,6% in the circular geometry. In the circular geometry, NEC curve reaches its peak in 259.3 kcps at an activity concentration of 34.1 kBq ml-1, for the elliptical geometry, the maximum peak is reached at 239.1 kcps at an activity concentration of 24.8 kBq ml-1. For the spatial resolution test we used a point source containing 18F with 4 MBq activity and acquisition time of 200 s. The measurements were acquired in three transaxials positions (x,y) in the center of FOV and, shifted in ¼ of the center of the FOV, summarizing 6 measurements for each geometry. For each one of these 6 measurements, we found the FWHM (Full width at half-maximum amplitude) and the FWTM (Full width at tenth-maximum amplitude) in the three axis (x,y,z), in this way, for each proposed geometry, we obtained 18 values of FWHM and 18 values of FWTM. The elliptical geometry showed improvement in the spatial resolution in FWHM in 4 of the 18 resolution values. For the FWTM, the elliptical geometry showed improvement in 8 of 18 resolution values. Regarding the FWHM, where there was an improvement in spatial resolution, we obtained the average gain of 18,7%. For the losses, in spatial resolution was an average of 43,26%. For the FWTM, the improvement in spatial resolution was an average percentage of 12,09%, while the loss of resolution had the average percentage of 45,59%. It can be concluded that the proposed geometry showed some advantages regarding the traditional geometry. In the elliptical geometry there is one reduction of 10 blocks of crystals in relation to the circular geometry, which possibly can cut fabrication costs of the tomography. Regarding to sensibility, there is a significant improvement for the new geometry, as well as one reduction of the activity concentration in which the tomography reaches the best performance, although the occurrence of a slight fall in the counts in the elliptical system. This reduction in the activity concentration can help to reduce the test time and the use less radioactive material, reducing the risk for the patients and the test costs, as well as improving the number of tests in the same period of time. The scattering fraction in the elliptical system is slight higher to the circular system. The major loss in the elliptical PET system is the spatial resolution, where there was not improvement for the great fraction of the obtained measurements, requiring some modifications that can be made, in special, in the crystal blocks arrangement. It is believed that some modifications to the angle of the detectors and in the formation of the coincidences can improve the resolutions and NEC.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-09T11:58:12Z No. of bitstreams: 1 adriananascimentodesouza.pdf: 1757133 bytes, checksum: 69514ee02274bd2e690a0252c528c6f5 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-26T20:25:02Z (GMT) No. of bitstreams: 1 adriananascimentodesouza.pdf: 1757133 bytes, checksum: 69514ee02274bd2e690a0252c528c6f5 (MD5) / Made available in DSpace on 2017-06-26T20:25:02Z (GMT). No. of bitstreams: 1 adriananascimentodesouza.pdf: 1757133 bytes, checksum: 69514ee02274bd2e690a0252c528c6f5 (MD5) Previous issue date: 2015-10-01 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho teve como objetivo a produção de uma cápsula selada de ²²Na, funcionando como fonte emissora de pósitrons, para a nova linha de pesquisa do Laboratório de Espectroscopia Atômica e Molecular (LEAM) da UFJF, que visa a aplicação de feixes de pósitrons lentos, ao invés de elétrons nos aparelhos disponíveis no LEAM, no estudo de átomos ou moléculas. O trabalho englobou várias etapas, tais como a escolha da fonte emissora de pósitrons, o armazenamento do radionuclídeo, o projeto da cápsula selada, sua construção, o desenvolvimento de um sistema de carregamento da cápsula, sua selagem, considerando todos os aspectos inerentes à proteção radiológica. A fonte emissora de pósitron escolhida foi o elemento radioativo 22Na, radioisótopo de meia vida longa (2,6 anos) e meia vida biológica (11 dias) razoavelmente baixa. Sua aplicação não é imediata e requer seu acondicionamento adequado e seguro em uma cápsula perfeitamente selada, sendo posteriormente, necessário moderar a energia dos pósitrons rápidos emitidos espontaneamente pela fonte. Esta é a primeira cápsula de 22Na selada produzida no Brasil, colocando-nos no seleto grupo de pesquisadores que dominam esta tecnologia. / This work aimed to produce a sealed capsule of ²²Na, consisting of a source of positrons for the new line of research of Atomic and Molecular Spectroscopy Laboratory (LEAM) - UFJF, to use optionally slow positron beams, rather than electrons, in the apparatus available in this laboratory to study atoms and molecules. The work encompassed several steps, such as the choice of the emission source of positrons, radionuclide storage, the sealed capsule design, its construction, the development of a charging system of the capsule, sealing, considering all aspects of inherent in radiological protection. The positron source chosen was the radioactive element ²²Na, long half-life radioisotope (2.6 years) and reasonably low biological half-life (11 days). Its application is not immediate and requires its proper and safe packaging in a perfectly sealed capsule, being subsequently necessary to moderate the energy of fast positrons spontaneously emitted by the source. This is the first ²²Na sealed capsule produced in Brazil, placing us in the select group of researchers who have mastered this technology.

Mechanical ventilation in itself can harm the lung and cause ventilator-induced lung injury (VILI), which can induce or aggravate acute respiratory distress syndrome (ARDS). Much debate remains over pivotal concepts regarding the pathophysiology of VILI, especially about the precise contribution, kinetics, and primary role of potential VILI mechanisms. Consequently, it remains largely unknown how best to design a well-timed and full-bodied mechanical ventilation strategy. Little is known also about small airways dysfunction in ARDS. Dynamic positron emission tomography (PET) with [18F]fluoro-2-deoxy-D-glucose (18F-FDG) can be used to image cellular metabolism, which during lung inflammation mainly reflects neutrophil activity, allowing the study of regional lung inflammation in vivo. We studied the regional evolution of inflammation using dynamic PET/CT imaging of 18F-FDG in VILI and during different lung-protective mechanical ventilation strategies. By dynamic CT we investigated also the location and magnitude of peripheral airway closure and alveolar collapse under high and low distending pressures and high and low inspiratory oxygen fraction. Piglets were submitted to an experimental model of early ARDS combining repeated lung lavages and injurious mechanical ventilation. The animals were subsequently studied during sustained VILI, or submitted to distinct approaches of lung-protective mechanical ventilation: the one recommended by the ARDS Network (ARDSNet), or to one defined as open lung approach (OLA). The normally and poorly aerated regions - corresponding to intermediate gravitational zones - were the primary targets of the inflammatory process accompanying early VILI, which may be attributed to the small volume of the aerated lung that receives most of ventilation. The ARDSNet strategy did not attenuate global pulmonary inflammation during 27h and led to a concentration of inflammatory activity in the upper and poorly aerated lung regions. The OLA, in comparison with the ARDSNet approach, resulted in sustained and better gas exchange and lung mechanics. Moreover, the OLA strategy resulted in less global and regional inflammation. Dynamic CT data suggested that a significant amount of airway closure and related reabsorption atelectasis occurs in acute lung injury. Whether potential distal bronchioles injury (“bronchiolotrauma”) is a critical and decisive element in ventilator-associated lung injury is a matter for future studies.

Gemcitabine is a highly potent chemotherapeutic nucleoside agent used in the treatment of several cancers and solid tumors. However, it is therapeutically limitated because of toxicity to normal cells and its rapid intracellular deamination by cytidine deaminase into the inactive uracil derivative. Modification at the 4-(N) position of gemcitabine's exocyclic amine to an -amide functionality is a well reported prodrug strategy which has been that confers a resistance to intracellular deamination while also altering pharmacokinetics of the parent drug. Coupling of gemcitabine to carboxylic acids with varying terminal moieties afforded the 4-N-alkanoylgemcitabines whereas reaction of 4-N-tosylgemcitabine with the corresponding alkyl amines gave the 4-N-alkylgemcitabines. The 4-N-alkanoyl and 4-N-alkyl gemcitabine analogues with a terminal hydroxyl group on the 4-N-alkanoyl or 4-N-alkyl chain were efficiently fluorinated either with diethylaminosulfur trifluoride or under conditions that are compatible with the synthetic protocols for 18F labeling, such as displacement of the corresponding mesylate with KF/Kryptofix 2.2.2. The 4-N-alkanoylgemcitabine analogues displayed potent cytostatic activities against murine and human tumor cell lines with 50% inhibitory concentration (IC50) values in the range of low nM, whereas cytotoxicity of the 4-N-alkylgemcitabine derivatives were in the low to modest µM range. The cytostatic activity of the 4-N-alkanoylgemcitabines was reduced by several orders of magnitude in the 2'-deoxycytidine kinase (dCK)-deficient CEM/dCK- cell line while the 4-N-alkylgemcitabines were only lowered by 2-5 times. None of the 4-N-modified gemcitabines were found to be substrates for cytosolic dCK, however all were found to inhibit DNA synthesis. As such, the 4-N-alkanoyl gemcitabine derivatives likely need to be converted to gemcitabine prior to achieving their significant cytostatic potential, whereas the 4-N-alkylgemcitabines reach their modest activity without "measurable" conversion to gemcitabine. Thus, the 4-N-alkylgemcitabines provide valuable insight on the metabolism of 4-N-modified gemcitabine prodrugs.

No description available.

Durant l'irradiation en réacteur la fission des atomes d'actinides entraine la création de grandes quantités de défauts, qui affecte les propriétés physiques et chimiques des matériaux dans le réacteur, en particulier les matériaux combustibles ou de structure. Une des méthodes non destructives pouvant être utilisées pour caractériser les défauts induits par irradiation, vides ou contenant les produits de fission, est la spectroscopie d'annihilation de positons (SAP). Cette technique expérimentale consiste à détecter le rayonnement généré lors de l'annihilation du paire électron-positon dans un échantillon et en déduire les propriétés de la matière étudiée. Les positons peuvent être piégés dans les défauts de type lacunaire dans les solides, et en mesurant leur temps de vie et les distribution de moment du rayonnement d'annihilation, on peut obtenir des informations sur les volumes libres et les environnements chimiques des défauts. Dans ce travail, des calculs de structure électronique des caractéristiques d'annihilation de positons ont été effectués en utilisant la théorie de la fonctionnelle de la densité à deux composants (TCDFT). Pour calculer les distributions de moment rayonnement d'annihilation, nous avons implémenté les méthodes nécessaires dans le code de calcul libre ABINIT. Les résultats théoriques ont été utilités pour contribuer à l'identification des défauts d'irradiation dans deux céramiques nucléaires, le carbure de silicium (SiC) et le dioxyde d'uranium (UO2). / During in-pile irradiation the fission of actinide nuclei causes the creation of large amounts of defects, which affect the physical and chemical properties of materials inside the reactor, in particular the fuel and structural materials. Positron annihilation spectroscopy (PAS) can be used to characterize irradiation induced defects, empty or containing fission products. This non-destructive experimental technique involves detecting the radiation generated during electron-positron annihilation in a sample and deducing the properties of the material studied. As positrons get trapped in open volume defects in solids, by measuring their lifetime and momentum distributions of the annihilation radiation, one can obtain information on the open and the chemical environments of the defects. In this work electronic structure calculations of positron annihilation characteristics were performed using two-component density functional theory (TCDFT). To calculate the momentum distributions of the annihilation radiation, we implemented the necessary methods in the open-source ABINIT program. The theoretical results have been used to contribute to the identification of the vacancy defects in two nuclear ceramics, silicon carbide (SiC) and uranium dioxide (UO2).

Introduction and Objectives Calcific aortic valve disease (CAVD) is the most common valvular disease, accounting for 50% of all valve disorders and is the third most common cardiovascular disease following coronary disease and hypertension.[1,2] Currently, there is no pharmacological agent capable of reversing or slowing down the progression of CAVD and treatment of severe cases consists of surgical repair or valve replacement[2]. Hence, there is a crucial need for earlier detection using predictive biomarkers that will allow for preventative intervention as opposed to post-symptomatic disease treatment or management. Namely, one target of particular interest is the expression of matrix metalloproteinases (MMPs) (specifically MMP-1, -2, and -9) which are upregulated in CAVD prior to calcification events and have been previously shown to serve as an attractive molecular imaging target.1–3 The primary objective of this study is to assess the feasibility of detecting biomarkers of CAVD by various in vivo imaging modalities, such as PET and echocardiography. In addition, this study assesses disease progression in various mouse strains to qualify an appropriate CAVD animal model. Methods In vivo and ex vivo imaging of C57Bl/6 and ApoE-/- (n = 8 per strain cohort) mouse models are used to link unique features of matrix remodelling with CAVD progression. At baseline and longitudinal follow-up (4, 8, and 12 months), in vivo hemodynamic impairment is assessed through echocardiography, and calcification and MMP activity are measured using PET with a series of radiotracers: [18F]NaF for calcification, [18F]BR351 for the molecular targets of MMP-2 and -9, and [18F]FMBP with molecular target specificity for MMP-13. Following imaging, aortic valve (AV) tissue is harvested, sectioned, and analyzed for calcification, inflammatory markers, collagen types, and MMP activity in AV leaflets. Tracer autoradiography, immunofluorescence, and in situ zymography are used to confirm in vivo imaging results with improved resolution and quantification in valves. Histological sample preparation, experimentation, and analyses are then repeated in human AV tissue samples for relative comparison of biomarker expression in animal models. Results Echocardiography suggests positive signs of disease progression in experimental animal models. In comparison to WT, ApoE-/- mice show: increased peak velocity (p<0.0001), decreased aortic valve area (p<0.001), and irregular valve dynamics. [18F]NaF PET imaging shows expected bone uptake and low calcium-burden in young and WT animals. [18F]FMBP shows increased uptake in the valve area of diseased models at later timepoints, 1.530 compared to <0.001 %ID/g (p<0.005), in disease vs control animals respectively. Furthermore, confirmation of sought-after biomarkers has also been assessed by analysis of various histological sample preparations including the presence of leaflet calcification, upregulation of MMP-2, -9, and -13, matrix remodelling, lipids, inflammatory markers, and activated MMP expression. Conclusion Findings from this study suggest that molecular imaging techniques using target-specific radiotracers, as well as echocardiography for assessment of hemodynamic impairment, are feasible solutions in predicting disease onset in CAVD specific animal models.

<p>Uprkos postojanju dijagnostičkih procedura za ranu dijagnostiku, sprovođenju preventivnog skrining programa, te dugom preinvazivnom periodu u kojem je moguće izvr&scaron;iti detekciju, karcinom grlića materice i dalje predstavlja jedan od vodećih zdravstvenih problema, imajući u vidu činjenicu da je uzrok obolevanja i umiranja velikog broja žena &scaron;irom sveta. Oko 85% karcinoma grlića materice dijagnostikuje se u zemljama u razvoju, čineći čak 15% svih malignih tumora kod žena, dok u razvijenim zemljama ovaj procenat iznosi 3,6% novootkrivenih karcinoma. Prema podacima Registra za rak Vojvodine, u AP Vojvodini u 2011. godini, od ukupnog broja novoregistrovanih malignih bolesti kod žena, karcinom grlića materice se nalazio na četvrtom mestu, sa procentualnim uče&scaron;ćem od 6,66%, dok je najveći broj novoobolelih slučajeva u starosnoj grupi 45&ndash;49 godina, pokazujući trend pomeranja prema mladjim starosnim grupama. Primena novih, savremenih dijagnostičkih metoda u inicijalnom zbrinjavanju obolelih od karcinoma grlića materice može doprineti pravilnijem tretmanu bolesti, utičući na tok bolesti, ishod i preživljavanje. PET/CT je hibridna imidžing metoda koja poslednjih godina zauzima značajno<br />mesto u određivanju stadijuma malignih bolesti i dijagnostikovanju recidiva, a kojom se stiče uvid u metaboličko/funkcionalni status ispitivanih tkiva i organa, superponiran na morfoanatomsku CT sliku. Kako je za cilj istraživanja postavljeno utvrđivanje značaja PET/CT pregleda u preoperativnoj evaluaciji karcinoma grlića materice, ispitanice koje su ispunjavale kriterijume za uključivanje u istraživanje su operisane nakon načinjenog PET/CT pregleda, a zatim su poređeni parametri dobijeni kliničkim pregledom, PET/CT pregledom, intraoperativnim pregledom i patohistolo&scaron;kim pregledom. Rezultati načinjenog istraživanja ukazuju da hibridni PET/CT imidžing ne demonstrira prednost u odnosu na dosada&scaron;nje preporuke vezane za preoperativnu dijagnostičku evaluciju ispitanica sa ranim stadijumom karcinoma grlića materice, naročito u detekciji postojanja primarnog tumora dimenzija manjih od 7mm i u detekciji prisustva mikrometastaza u lokoregionalnim limfnim čvorovima zbog jo&scaron; uvek ograničene prostorne rezolucije. PET/CT je pokazao izuzetno visoku specifičnost u utvrđivanju nepostojanja primarnog tumora i visoku komplementarnost sa patohistolo&scaron;kim nalazom. Uočeno je da PET/CT demonstrira statistički značajniju tačnost u proceni stepena pro&scaron;irenosti osnovne bolesti u odnosu na kliničko i intraoperativno utvrđivanje stepena pro&scaron;irenosti osnovne bolesti. Standardizovana vrednost preuzimanja radiofarmaka (SUV) zavisna od histolo&scaron;kog tipa karcinoma grlića materice, demonstrirajući najvi&scaron;e vrednosti u planocelularnom karcinomu i u lo&scaron;e diferentovanom tip G3 karcinomu grlića materice, pozitivno korelirajući sa promerom tumora. Pokazujući značajan potencijal u detekciji primarnog karcinoma grlića materice, kao i u detekciji metastaza u lokoregionalnim limfnim čvorovima, PET/CT nalazi svoje mesto u dijagnostičkoj obradi bolesnica sa karcinomom grlića materice.</p> / <p>Despite the existence of the diagnostic procedures for early diagnosis, implementing preventive screening programs and long preinvasive period in which it is possible to perform detection, cervical cancer remains one of the leading health problems, bearing in mind the fact that it is the cause of morbidity and mortality of a large number of women throughout the world. About 85% cases of cervical cancer are diagnosed in underdeveloped and developing countries. In economically underdeveloped countries, cervical cancer accounts for 15% of all malignant tumors in women, whereas in developed countries it is 3.6% of new cancers. According to data from the Cancer Registry of Vojvodina, in AP Vojvodina, in 2011, of the total number of newly registered malignant diseases in women, cervical cancer was in fourth place, with a percentage share of 6.66% , the largest number of new cases is in the 45-49 years age group, with the shifting the peak in the incidence of cervical cancer towards younger age groups. Applying of new diagnostic methods in the initial management of patients with cervical cancer, indirectly affect the course of the disease, its treatment, and survival. PET-CT hybrid imaging method in recent years occupies an important place in the staging of malignant disease and the diagnosis of recurrence, showing the functional state of certain tissues and organs (PET) with anatomical details (CT). As the aim of this study was to assess the importance of PET / CT scans in the preoperative evaluation of cervical cancer, the women who met the criteria were included in the study, and were operated after having PET / CT scans done, after which the parameters of the results of clinical examination, PET / CT examination, intraoperative examination and histopathological examination, were compared. It was observed that the hybrid PET / CT imaging does not demonstrate the advantage compared to the previous recommendations related to the preoperative diagnostic evaluation of patients with early-stage cervical cancer, especially in the detection of primary tumor measuring less than 7mm and the detection of the presence of micrometastases in the locoregional lymph nodes, due to the still limited spatial resolution. PET / CT showed extremely high specificity in determining the absence of primary tumor and high complementarity with histopathological findings. The study showed that PET / CT demonstrates statistically more significant accuracy in the assessment of the extent of the underlying disease, compared with the clinical and intraoperative determination of the extent of the underlying disease. It has been shown that the standardized uptake value of radiopharmaceuticals (SUV) depends on the histological type of cervical cancer, demonstrating the highest values in squamous-cell carcinoma and then in poorly differentiated G3 carcinoma of the cervix, positively correlating with the diameter of the tumor. Demonstrating significant potential in the detection of primary cervical cancer, as well as in the detection of metastases in locoregional lymph nodes, PET / CT has its place in diagnostic treatment of patients with cervical cancer.</p>

No description available.

La prise en charge des cancers bronchiques localisés et localement avancés reste un challenge thérapeutique en cas de traitement par radiothérapie ou radio-chimiothérapie avec des taux d’échec importants. Il a été démontré que la Tomographie par Emission de Positons (TEP) au FDG était indispensable dans la stadification et la planification de la radiothérapie des cancers bronchiques non à petites cellules. De nombreux travaux ont proposé d’adapter le traitement de radiothérapie aux données de la TEP du métabolisme (FDG) mais également à partir de la TEP de l’hypoxie. Nous avons au cours des dernières années essayé de définir les différentes stratégies d’adaptation de la radiothérapie à partie des données de l’imagerie fonctionnelle. Dans le premier travail (travail 1), nous avons analysé les différentes méthodes de segmentation de traceurs à faible contraste pour obtenir des méthodes reproductibles et utilisables au cours d’essais thérapeutiques multicentriques. Ce travail a permis de définir une méthode de segmentation pour le FMISO (traceur de l’hypoxie) mais également pour la FLT qui permet de définir la prolifération. Le second travail (travail 2a et 2b) est le résultat de l’étude multicentrique d’augmentation de dose de radiothérapie à partir des données de la TEP FMISO. Dans ce travail, nous avons proposé de réaliser un boost de radiothérapie chez les patients présentant des tumeurs hypoxiques. Il a été démontré qu’une augmentation modérée de la dose de radiothérapie permettait d’obtenir le même contrôle local à 3 mois pour des tumeurs pourtant plus volumineuses et une tendance à un contrôle supérieur à 3 ans chez les patients ayant pu bénéficié d’un boost par rapport à ceux traités à 66Gy (26.5 mois versus 15.3 mois). Les travaux suivants (travaux 3 et 4) s’intéressent à l’hétérogénéité de fixation de la TEP-FDG et aux méthodes de segmentation de ce traceur en per-radiothérapie. Ces données permettent d’envisager des doses de radiothérapie hétérogènes avec des augmentations ciblées sur les volumes les plus hypermétaboliques en pré-traitement ou sur les volumes pour lesquels il persiste une fixation pathologique en cours de traitement. Les travaux 5 et 6 s’intéressent aux corrélations entre les zones les plus hypermétaboliques (FDG) et les zones hypoxiques (FMISO). Dans un premier temps, nous mettons en évidence le manque de corrélation entre ces 2 traceurs puis dans un second temps l’impact dosimétrique des différentes stratégies de radiothérapie adaptative basée sur la TEP du métabolisme ou de l’hypoxie. Dans le dernier travail (travail 7), nous avons comparé les résultats de deux traceurs de l’hypoxie chez des patients traités par chirurgie pour un cancer bronchique ; ces données ont été comparées aux données d’immunohistochimie pour permettre une meilleure connaissance des traceurs de l’hypoxie. L’ensemble de ces travaux doit permettre une meilleure identification des stratégies de radiothérapie adaptative basée sur l’imagerie fonctionnelle par TEP du métabolisme ou de l’hypoxie. / Résumé en anglais non disponible