C. burnetii est une bactérie intracellulaire strcite. Récemment, un milieu axénique, nommé ACCM 2 a été développé, et permet la culture de cette bactérie en atmosphère microaérophile. Nous avons testé si l’ajout d’acide urique dans le milieu de culture pouvait permettre une culture en milieu aérobie. Nous avons observé une croissance de C. burnetii incubée en conditions aérobies dans le milieu ACCM2 enrichi en acide urique. A Cayenne, en Guyane Française, les pneumopathies causées par C. burnetii sont fréquentes et sévères. Nous avons analysé le génome d’une souche isolée à Cayenne. Ce travail a mis en évidence une délétion de 6105 pb intéressant le gène du système de sécrétion de type 1 (T1SS). Cette réduction de génome est probablement impliquée dans l’hypervirulence des souches de Cayenne. Enfin, nous avons testé la sensibilité aux antibiotiques de 6 souches isolées à partir de patients vivant à Cayenne. Ces souches étaient toutes sensibles à la doxycycline et résistantes aux macrolides. Dans une troisième partie nous avons analysé l’apport du TEP scanner dans le diagnostic des infections à C. burnetii. 167 patients atteints d’infections à C. burnetii ont bénéficié d’un TEP scanner. Nous avons retrouvé une proportion élevée de fixations ostéo-articulaires (21) et ganglionnaires (27), et nous avons proposé de nouvelles définitions pour ces localisations. Nous avons ensuite étudié l’impact du traitement chirurgical chez les patients atteints d’infections vasculaires. Une analyse rétrospective de 86 patients atteints d’infections vasculaires a montré que la chirurgie était associée à une diminution de la mortalité à 2,5 ans et à une meilleure évolution sérologique / C. burnetii is an intracellular bacterium. Recently, an axenic medium, named ACCM 2, has been developed and allows the culture of this bacterium in a microaerophilic atmosphere. We tested if the addition of uric acid in the medium could allow an aerobic culture. We observed growth of C. burnetii incubated under aerobic conditions in the ACCM2 medium enriched with uric acid. In Cayenne, French Guiana, pneumonia caused by C. burnetii are frequent and severe. We analyzed the genome of a strain from Cayenne. This work revealed a 6105 bp deletion in the gene of the type 1 secretion system (T1SS). This genome reduction is probably involved in the hypervirulence of Cayenne strains. Finally, we tested the antibiotic suceptibility of 6 strains isolated from patients living in Cayenne. These strains were all susceptible to doxycycline and resistant to macrolides. In a third part we analyzed the contribution of PET scanner in the diagnosis of C. burnetii infections. 167 patients with C. burnetii infections benefited from a PET scan. We found a high proportion of osteo-articular (21) and lymphadenitis (27) fixations, and we proposed new definitions for these locations. We then investigated the impact of surgical treatment in patients with vascular infections. A retrospective analysis of 86 patients with vascular infections showed that surgery was associated with a lower mortality at 2.5 years and a better serological outcome

SAMMANFATTNING Bakgrund: Vid hjärnundersökningar finns även andra strukturer utanför hjärnan som är innerverade av nervsystemet. Det är möjligt att sjukdomen i hjärnan avspeglas där också. Det finns många sjukdomar och tillstånd med liknande symptom och att ställa rätt diagnos kan vara svårt. Många sjukdomar påverkar det autonoma nervsystemet och ett sätt att hitta rätt diagnos kan vara att undersöka hur det fungerar.  Syfte: Att se vilka variationer av radioaktivitetsupptag som fanns i parotiskörtlarna mellan patienterna som avbildades med 11C-PE2I PET/DT. Samt att kunna se om denna information kan utnyttjas till att identifiera dysfunktion av autonoma nervsystemet (MRT-bilder är även en tillhjälps verktyg). Metod: Studiedesignen var en retrospektiv kvantitativ studie. Hundra (konsekutiva) patienter indelades i grupper så som: normal, Parkinsons, Parkinsons sjukdom med kombination av vaskulära förändringar och atypisk Parkinson sjukdom. Isotopupptag i basala ganglier och parotiskörtlar har mätts. Några patienters MRT- bilder var tillgängligt till kvantifiering.   Resultat: kombinerade gruppen med Parkinsons sjukdom, atypisk Parkinsons sjukdom och vaskulära förändringar har en uppreglering av antalet fria dopaminreceptorer i parotis jämfört med friska (även i bara PSP samt bara vaskulära grupper) med (p <0.05).   Slutsats: Det finns variation av upptaget mellan en del av grupper därmed kan sjukdomen i hjärnan avspeglas i körtlar också.   Nyckelord: Neurodegenerativa sjukdomar, Autonom dysfunktion, 11CPE2I-PET/DT, parotiskörtlar, basala ganglier / ABSTRACT Background: At brain examination, there are also other structures outside the brain that are innervated by the nervous system. It is possible that the disease of the brain is reflected there as well. There are many diseases and conditions with similar symptoms and making the right diagnosis can be difficult. Many diseases affect the autonomic nervous system and one way to find the right diagnosis may be to investigate how it works.     Purpose: to see what variations in radioactivity uptake were found in the parotic glands between the patients depicted with the 11C-PE2I PET/CT. As well as being able to see how valuable this information is in being used to identify dysfunction of the autonomic nervous system (MRT- images are also an aids tool).   Method: The study design was a retrospective quantitative study. One hundred (consecutive) patients were divided in groups such as normal, Parkinson's, Parkinson's disease with combination of vascular changes and atypical Parkinson's disease. Isotope uptake in basal ganglia and parotic glands has been measured. Some patients' MRT images were available for quantification.     Result: the results show that the combined group of Parkinson's disease, atypical Parkinson's disease and vascular changes has an upregulation of the number of free dopamine receptors in parotid compared to healthy ones (also in PSP only and only vascular groups) with (p <0.05).    Conclusion: There is variation of uptake between some of the groups thus the disease in the brain can be reflected in glands as well.     Keywords: Neurodegenerative Diseases, Autonomic Dysfunction, 11CPE2I-PET/CT, Parotid Glands, Basal Ganglia

Le cancer du sein est une pathologie fréquente pour lequel les examens TEP/TDM au ¹⁸F-FDG et IRM mammaire sont fréquemment réalisés en routine. Il existe cependant une sous-utilisation des informations apportées par chacune de ces techniques d'imagerie. En pratique, l’interprétation de ces examens est principalement basée sur l’analyse visuelle et l'analyse « quantitative » se résume généralement au SUVmax seul en TEP/TDM et à l’étude du rehaussement du signal après injection de produit de contraste en IRM mammaire (DCE-MRI). L’arrivée de nouvelles machines hybrides TEP/ IRM, nous a amené à évaluer l'apport d’une quantification avancée des images issues de chacune de ces modalités séparément et en combinaison. Cela rejoint un domaine en expansion « la radiomique » qui consiste à extraire un grand nombre de caractéristiques quantitatives des images médicales pour décrypter l’hétérogénéité tumorale ou améliorer la prédiction du pronostic.L’objectif de notre travail était d’étudier l’apport des données radiomiques extraites de l’imagerie TEP au ¹⁸F-FDG et de l’IRM avec injection de produit de contraste réalisées avant traitement pour caractériser l’hétérogénéité tumorale dans le cancer du sein, en prenant en compte les différents sous-types moléculaires de cancer du sein, à savoir les tumeurs luminales (Lum A, Lum B HER2- et Lum B HER2+), triple-négatives et HER2+. Une importance particulière a été portée sur la valeur prédictive des informations radiomiques extraites de ces 2 techniques d’imagerie pour prédire le pronostic dans un groupe de patientes traitées par chimiothérapie néo-adjuvante. L’influence de variations physiologiques telles que l’âge sur le calcul des données radiomiques dans le tissu mammaire normal et cancéreux séparément a également été explorée, de même que la variabilité multicentrique des index radiomiques. L’extraction de ces données radiomiques a été effectuée grace au logiciel LiFex développé au sein du laboratoire IMIV sur une base de données-patientes recueillie en rétrospective.Nous avons rapporté pour la première fois l’influence de l’âge sur le calcul des indices « radiomiques » en TEP dans le tissu mammaire sain dans 2 institutions différentes mais aussi dans les tumeurs mammaires notamment celle triple-négatives. Des associations significatives entre le « phénotype tumoral radiomique » en imagerie TEP et IRM et des données pronostiques reconnues dans le cancer du sein ont été mises en évidence. En outre, nous avons démontré l’existence d’une grande variabilité pour le « profil radiomique » en TEP parmi les tumeurs présentant le même sous-type moléculaire. Cela suggére l’existence d’informations non-redondantes au sein du « phénotype tumoral métabolique » de chaque tumeur mammaire défini par les données radiomiques. L’exploration de cette variabilité s’est révélée intéressante pour améliorer la prédiction de la réponse histologique chez les patientes avec des tumeurs triple-négatives traitées par chimiothérapie néo-adjuvante. Par ailleurs, les mesures effectuées dans la région mammaire péri-tumorale chez les patientes traitées par chimiothérapie néo-adjuvante se sont montrées prédictives pour les patientes avec des tumeurs Lum B HER2-. En IRM nous avons montré l’importance de standardiser la méthode de mesure des caractéristiques radiomiques. Nous avons observé que les caractéristiques radiomiques issues des images DCE-MRI étaient moins associées aux caractéristiques moléculaires des tumeurs et avaient une valeur prédictive moindre. Nous avons également proposé une nouvelle méthode relativement standardisée pour le calcul des données radiomiques en IRM mammaire avec des résultats intéressants mais cette méthode doit encore être optimisée. Cependant, nos résultats suggèrent que les données extraites de la totalité du volume tumorale en IRM compléteraient efficacement les caractéristiques radiomiques TEP et le sous-type moléculaire pour prédire la réponse à la chimiothérapie néo-adjuvante. / Breast cancer is a common disease for which ¹⁸F-FDG PET/CT and breast MRI are frequently performed in routine practice. However, the different information provided by each of these imaging techniques are currently under-exploited. Indeed, in routine the interpretation of these scans is mainly based on visual analysis whereas the « quantitative » analysis of PET/CT data is generally limited to the sole use of the SUVmax while in breast MRI, simple parameters to characterize tumor enhancement after injection of contrast medium are used. The advent of PET/MRI machines, calls for an evaluation of the contribution of a more advanced quantification of each of the modalities separately and in combination in the setting of breast cancer. This is along with the concept of « Radiomics » a field currently expanding and which consists in extracting many quantitative characteristics from medical images used in clinical practice to decipher tumor heterogeneity or improve prediction of prognosis. The aim of our work was to study the contribution of radiomic data extracted from ¹⁸F-FDG PET and MRI imaging with contrast injection to characterize tumor heterogeneity in breast cancer taking into account the different molecular subtypes of breast cancer, namely luminal (Lum A, Lum B HER2- and Lum B HER2 +), triple-negative and HER2 + tumors. In this context, we focused on the prediction of prognosis in patients treated with neo-adjuvant chemotherapy. The influence of physiological variations such as age on the calculation of radiomic data in normal breast and breast tumors separately was also explored, as well as the multi-center variability of radioman features. Radiomic features were extracted using the LiFex software developed within IMIV laboratory. The patient database used for the studies were all retrospective data. We reported for the first time the influence of age on the values of radiomic features in healthy breast tissue in patients recruited from 2 different institutions but also in breast tumors especially those with a triple-negative subtype. Similarly, significant associations between the radiomic tumor phenotype in PET and MRI imaging and well-established prognostic factors in breast cancer have been identified. In addition, we showed a large variability in the PET « radiomic profile » of breast tumors with similar breast cancer subtype suggesting complementary information within their metabolic phenotype defined by radiomic features. Moreover, taking into account this variability has been shown to be of particular interest in improving the prediction of pathological response in patients with triple-negative tumors treated with neoadjuvant chemotherapy. A peri-tumoral breast tissue region satellite to the breast tumor was also investigated and appeared to bear some prognostic information in patients with Lum B HER2- tumors treated with neoadjuvant chemotherapy. In MR, we demonstrated the need to harmonize the methods for radiomic feature calculation. Overall, we observed that radiomic features derived from MR were less informative about the molecular features of the tumors than radiomic features extracted from PET data and were of lower prognostic value. Yet, the combination of the enhanced tumor volume in MR with a PET radiomic feature and the tumor molecular subtype yielded enhanced the accuracy with which response to neoadjuvant therapy could be predicted compared to features from one modality only or molecular subtype only.

A presença da Medicina Nuclear como modalidade de obtenção de imagens médicas é um dos principais procedimentos utilizados hoje nos centros de saúde, tendo como grande vantagem a capacidade de analisar o comportamento metabólico do paciente, traduzindo-se em diagnósticos precoces. Entretanto, sabe-se que a quantificação em Medicina Nuclear é dificultada por diversos fatores, entre os quais estão a correção de atenuação, espalhamento, algoritmos de reconstrução e modelos assumidos. Neste contexto, o principal objetivo deste projeto foi melhorar a acurácia e a precisão na análise de imagens de PET/CT via processos realísticos e bem controlados. Para esse fim, foi proposta a elaboração de uma estrutura modular, a qual está composta por um conjunto de passos consecutivamente interligados começando com a simulação de phantoms antropomórficos 3D para posteriormente gerar as projeções realísticas PET/CT usando a plataforma GATE (com simulação de Monte Carlo), em seguida é aplicada uma etapa de reconstrução de imagens 3D, na sequência as imagens são filtradas (por meio do filtro de Anscombe/Wiener para a redução de ruído Poisson caraterístico deste tipo de imagens) e, segmentadas (baseados na teoria Fuzzy Connectedness). Uma vez definida a região de interesse (ROI) foram produzidas as Curvas de Atividade de Entrada e Resultante requeridas no processo de análise da dinâmica de compartimentos com o qual foi obtida a quantificação do metabolismo do órgão ou estrutura de estudo. Finalmente, de uma maneira semelhante imagens PET/CT reais fornecidas pelo Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP) foram analisadas. Portanto, concluiu-se que a etapa de filtragem tridimensional usando o filtro Anscombe/Wiener foi relevante e de alto impacto no processo de quantificação metabólica e em outras etapas importantes do projeto em geral. / The presence of Nuclear Medicine as a medical imaging modality is one of the main procedures utilized nowadays in medical centers, and the great advantage of that procedure is its capacity to analyze the metabolic behavior of the patient, resulting in early diagnoses. However, the quantification in Nuclear Medicine is known to be complicated by many factors, such as degradations due to attenuation, scattering, reconstruction algorithms and assumed models. In this context, the goal of this project is to improve the accuracy and the precision of quantification in PET/CT images by means of realistic and well-controlled processes. For this purpose, we proposed to develop a framework, which consists in a set of consecutively interlinked steps that is initiated with the simulation of 3D anthropomorphic phantoms. These phantoms were used to generate realistic PET/CT projections by applying the GATE platform (with Monte Carlo simulation). Then a 3D image reconstruction was executed, followed by a filtering process (using the Anscombe/Wiener filter to reduce Poisson noise characteristic of this type of images) and, a segmentation process (based on the Fuzzy Connectedness theory). After defining the region of interest (ROI), input activity and output response curves are required for the compartment analysis in order to obtain the Metabolic Quantification of the selected organ or structure. Finally, in the same manner real images provided from the Heart Institute (InCor) of Hospital das Clínicas, Faculty of Medicine, University of São Paulo (HC-FMUSP) were analysed. Therefore, it is concluded that the three-dimensional filtering step using the Ascombe/Wiener filter was preponderant and had a high impact on the metabolic quantification process and on other important stages of the whole project.

A presença da Medicina Nuclear como modalidade de obtenção de imagens médicas é um dos principais procedimentos utilizados hoje nos centros de saúde, tendo como grande vantagem a capacidade de analisar o comportamento metabólico do paciente, traduzindo-se em diagnósticos precoces. Entretanto, sabe-se que a quantificação em Medicina Nuclear é dificultada por diversos fatores, entre os quais estão a correção de atenuação, espalhamento, algoritmos de reconstrução e modelos assumidos. Neste contexto, o principal objetivo deste projeto foi melhorar a acurácia e a precisão na análise de imagens de PET/CT via processos realísticos e bem controlados. Para esse fim, foi proposta a elaboração de uma estrutura modular, a qual está composta por um conjunto de passos consecutivamente interligados começando com a simulação de phantoms antropomórficos 3D para posteriormente gerar as projeções realísticas PET/CT usando a plataforma GATE (com simulação de Monte Carlo), em seguida é aplicada uma etapa de reconstrução de imagens 3D, na sequência as imagens são filtradas (por meio do filtro de Anscombe/Wiener para a redução de ruído Poisson caraterístico deste tipo de imagens) e, segmentadas (baseados na teoria Fuzzy Connectedness). Uma vez definida a região de interesse (ROI) foram produzidas as Curvas de Atividade de Entrada e Resultante requeridas no processo de análise da dinâmica de compartimentos com o qual foi obtida a quantificação do metabolismo do órgão ou estrutura de estudo. Finalmente, de uma maneira semelhante imagens PET/CT reais fornecidas pelo Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP) foram analisadas. Portanto, concluiu-se que a etapa de filtragem tridimensional usando o filtro Anscombe/Wiener foi relevante e de alto impacto no processo de quantificação metabólica e em outras etapas importantes do projeto em geral. / The presence of Nuclear Medicine as a medical imaging modality is one of the main procedures utilized nowadays in medical centers, and the great advantage of that procedure is its capacity to analyze the metabolic behavior of the patient, resulting in early diagnoses. However, the quantification in Nuclear Medicine is known to be complicated by many factors, such as degradations due to attenuation, scattering, reconstruction algorithms and assumed models. In this context, the goal of this project is to improve the accuracy and the precision of quantification in PET/CT images by means of realistic and well-controlled processes. For this purpose, we proposed to develop a framework, which consists in a set of consecutively interlinked steps that is initiated with the simulation of 3D anthropomorphic phantoms. These phantoms were used to generate realistic PET/CT projections by applying the GATE platform (with Monte Carlo simulation). Then a 3D image reconstruction was executed, followed by a filtering process (using the Anscombe/Wiener filter to reduce Poisson noise characteristic of this type of images) and, a segmentation process (based on the Fuzzy Connectedness theory). After defining the region of interest (ROI), input activity and output response curves are required for the compartment analysis in order to obtain the Metabolic Quantification of the selected organ or structure. Finally, in the same manner real images provided from the Heart Institute (InCor) of Hospital das Clínicas, Faculty of Medicine, University of São Paulo (HC-FMUSP) were analysed. Therefore, it is concluded that the three-dimensional filtering step using the Ascombe/Wiener filter was preponderant and had a high impact on the metabolic quantification process and on other important stages of the whole project.

Identification and localization of FDG-avid lymphoma lesions in PET-CT image volumes is of high importance for the diagnosis and monitoring of treatment progress in lymphoma patients. This process is tedious, time-consuming, and error-prone, due to large image volumes and the heterogeneity of lesions. Thus, a fully automatic method for lymphoma detection is desirable. The AutoPET challenge dataset contains 145 full-body FDG-PET-CT images of lymphoma patients with pixel-level segmentation of lesions. The Retina U-Net utilizes semantic segmentation maps for object detection through simultaneous segmentation and detection. More recently, transformer-based methods became increasingly popular due to their good performance. Here, TransRUnet is proposed, a 2D deep neural network capable of segmentation and object detection, combining the Retina U-Net with a Feature Pyramid Transformer. Firstly, a Retina U-Net was trained as a Baseline on 2D axial slices of 116 patient volumes from the AutoPET dataset, achieving an mAP of 0.377 and a DSC of 0.737 on the 29 test patients. Secondly, the TransRUnet was trained on the same patients, achieving an mAP and DSC of 0.285 and 0.732, respectively. Performance comparison based on mAP and DSC did not show significant differences (p = 0.596 and p = 0.940, for mAP and DSC, respectively) between the Retina U-Net and the TransRUnet. Furthermore, a substantial difference in FROC between the two models could not be observed. The ground truth data should be preprocessed to reduce noise in the training data or a 3D generalization of the TransRUnet should be used to improve the detection performance. / Att i PET-CT-bildvolymer identifiera och lokalisera lymfomlesioner med hög FDG-aviditet är av stor betydelse för diagnos och övervakning av behandlingseffekt hos lymfompatienter. Denna process är omständlig, tidskrävande och felbenägen på grund av stora bildvolymer och heterogeniteten hos lesionerna. Därför är det önskvärt med en helautomatisk metod för lymfomdetektion. AutoPET Challenge-datasetet innehåller 145 FDG-PET-CT-bilder av lymfom-patienter med segmentering av lesioner på pixelnivå. Retina U-Net använder semantiska segmenteringskartor för objektsdetektering genom samtidig segmentering och detektering. På senare tid har transformatorbaserade metoder blivit alltmer populära på grund av sina goda prestanda. Här föreslås TransRUnet, ett djupgående neuralt 2D-nätverk som kan segmentera och upptäcka objekt och som kombinerar Retina U-Net med en Feature Pyramid Transformer. I första steget tränades ett Retina U-Net som baslinje på 2D axialskivor av 116 patientvolymer från AutoPET-dataset, och uppnådde en mAP på 0,377 och en DSC på 0,737 på de 29 testpatienterna. I nästa steg tränades TransRUnet på samma patienter och uppnådde en mAP och DSC på 0,285 respektive 0,732. Jämförelse av prestanda baserat på mAP och DSC visade inga signifikanta skillnader (p = 0,596 och p = 0,940 för mAP respektive DSC) mellan Retina U-Net och TransRUnet. Dessutom kunde ingen väsentlig skillnad i FROC mellan de två modellerna observeras. Ground truth-data bör förbehandlas för att minska bruset i träningsdata eller också bör en 3D-generalisering av TransRUnet användas för att förbättra detektionsprestanda.

Background: PET nuclides can have a considerable influence on the spatial resolution and image quality of PET/CT scans, which can influence diagnostics in oncology, for example. The individual impact of the positron energy of ¹⁸F, ⁶⁸Ga, and ⁶⁴Cu on spatial resolution and image quality was compared for PET/CT scans acquired using a clinical, digital scanner. - Methods: A Jaszczak phantom and a NEMA PET body phantom were filled with ¹⁸F-FDG, ⁶⁸Ga-HCl, or ⁶⁴Cu-HCl, and PET/CT scans were performed on a Siemens Biograph Vision. Acquired images were analyzed regarding spatial resolution and image quality (recovery coefficients (RC), coefficient of variation within the background, contrast recovery coefficient (CRC), contrast–noise ratio (CNR), and relative count error in the lung insert). Data were compared between scans with different nuclides.- Results: We found that image quality was comparable between ¹⁸F-FDG and ⁶⁴Cu-HCl PET/CT measurements featuring similar maximal endpoint energies of the positrons. In comparison, RC, CRC, and CNR were degraded in ⁶⁸Ga-HCl data despite similar count rates. In particular, the two smallest spheres of 10 mm and 13 mm diameter revealed lower RC, CRC, and CNR values. The spatial resolution was similar between ¹⁸F-FDG and ⁶⁴Cu-HCl but up to 18% and 23% worse compared with PET/CT images of the NEMA PET body phantom filled with ⁶⁸Ga-HCl. - Conclusions: The positron energy of the PET nuclide influences the spatial resolution and image quality of a digital PET/CT scan. The image quality and spatial resolution of ⁶⁸Ga-HCl PET/CT images were worse than those of ¹⁸F-FDG or ⁶⁴Cu-HCl despite similar count rates.

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Introdução: O câncer do esôfago é uma das neoplasias do aparelho digestivo com maior gravidade e que apresenta grande morbimortalidade, mesmo quando o diagnóstico é precoce. A maioria dos pacientes é diagnosticado nos estágios avançados. O tratamento depende do estadiamento da neoplasia que avalia a profundidade de invasão do tumor (T), a disseminação linfonodal (N) e a presença de metástases a distância (M) e segue as orientações da União Internacional Contra o Câncer (UICC). Nas últimas décadas o estadiamento era realizado convencionalmente pela tomografia computadorizada (TC) e atualmente com a utilização de equipamentos que avaliam o metabolismo glicolítico do tumor como o 18F-FDG-PET e o PET-CT. Este estudo teve como Objetivo avaliar a relação entre a tomografia computadorizada e os métodos metabólicos como o 18F-FDG-PET e PET-CT, no estadiamento e tratamento do Adenocarcinoma e do Carcinoma Espinocelular (CEC) do esôfago. Método: Foram avaliados 331 pacientes com diagnóstico de Adenocarcinoma e CEC do esôfago entre 2008 e 2014. Destes, 55 pacientes (16,6%) apresentaram Adenocarcinoma e 276 (83,4%) apresentaram CEC. A idade variou de 38 a 92 anos, com média de 62,9 (+/- 9,8) anos. Inicialmente foram submetidos ao estadiamento com TC e proposta de conduta cirúrgica curativa ou tratamento paliativo. Posteriormente foram avaliados com a inclusão do 18F-FDG-PET ou do PET-CT e foi definida a conduta final. Resultados: A proporção de linfonodos positivos (N+) na tomografia foi de 71%, enquanto que nos métodos metabólicos foi de 70,1% (p=0,834), contudo, com pequena concordância (Kappa=0,339). A proporção de metástases (M1) encontradas na TC foi de 44,1% e no PET-CT 47,1%. Para metástases, o teste Kappa mostrou que os dois métodos apresentam uma concordância regular (0,452), apresentando mudanças de estadiamento em 36,5% dos indivíduos, sendo 19,3% com sobre estadiamento e 17,2% com subestadiamento. Entretanto, apenas 63 pacientes (19%) apresentaram mudança de conduta final e esta foi maior nos pacientes com sobre estadiamento (67,2%) (p < 0,005). Nos pacientes com Adenocarcinoma, observou-se um número maior de subestadiamento (32,7%), comparado àqueles com CEC (15,4%) (p < 0,0001), entretanto, sem apresentar diferença estatisticamente significativa quando avaliada a mudança de conduta. Avaliando individualmente os 140 pacientes estadiados com 18F-FDG-PET, 52,9% apresentaram linfonodos positivos (N+), valor semelhante à tomografia (p=0,053), entretanto com concordância pequena, cerca de 32,9% destes com metástases (M1) (p=0,749) e com concordância regular entre os métodos. Após o estadiamento, ocorreu uma mudança de conduta de 23,6% quando avaliado por equipe multidisciplinar. Com o uso do PET-CT, a proporção de tumores T4 foi de 27,2% (p=0,071), porém, com concordância boa com a tomografia (Kappa=0,616). A proporção de linfonodos positivos (N+) foi de 82,7%, com pequena concordância com a tomografia (Kappa=0,392). A proporção de metástases (M1) no PET-CT foi de 57,6%, com concordância regular (Kappa=0,465). Apresentaram mudança de estadiamento 34% dos indivíduos, sendo 19,3% com sobre estadiamento e 14,7% com subestadiamento. Entretanto, dos 191 pacientes, apenas 30 (15,7%) apresentaram mudança de conduta final, sendo que 67,6% ocorreu nos casos com sobre estadiamento, quando comparada aos casos com subestadiamento (17,9%) (p < 0,005). Pacientes com Adenocarcinoma apresentaram um número maior de subestadiamento (30%), comparado àqueles com CEC (11,8%), (p < 0,0001), entretanto, sem apresentar diferença estatisticamente significativa. A sobrevida global, quando avaliados com PET-CT, foi em torno de 30% após 30 meses, sendo semelhante tanto no grupo de pacientes em que houve mudança de conduta quanto no grupo em que esta mudança de conduta não ocorreu. Conclusão: Conclui-se, portanto, que no estadiamento tomográfico com 18F-FDG-PET e com PET-CT foi identificado um número expressivo de pacientes em estágios avançados, entretanto estes achados muitas vezes diferem entre si. A mudança de conduta ocorre em número expressivo de pacientes e geralmente nos casos em que ocorre sobre estadiamento. Embora o Adenocarcinoma apresente um número maior de casos de subestadiamento que o CEC, esta mudança de estadiamento não se reflete na mudança de conduta quando comparados. Torna-se importante, portanto, a avaliação multiprofissional em serviço de excelência no momento de decisão sobre a melhor terapêutica. Por fim, observamos a mesma curva de sobrevida entre aqueles pacientes em que há certeza da conduta a ser tomada e aqueles em que a conduta foi mudada após o uso do PET-CT, o que corrobora a necessidade da utilização em conjunto desses dois métodos / Introduction: Esophagus cancer is one of the most serious neoplasms of the digestive tract that presents great morbidity and mortality even in early diagnosis. Most patients are diagnosed in advanced stages. Treatment depends on tumor staging, which evaluates the depth of tumor invasion (T), lymph node spread (N) and the presence of distant metastases (M) and follow the guidelines of Union for International Cancer Control (UICC). In the last decades, staging was performed conventionally by computed tomography (CT) and currently with the use of equipments that evaluates tumor glycolytic metabolism such as 18F-FDG-PET and PET-CT. This study has as main Objective to evaluate the relationship between computed tomography and metabolic methods such as 18F-FDG-PET and PET-CT in the staging and treatment of Adenocarcinoma and Spinocellular Carcinoma (SCC) of the esophagus. Method: A total of 331 patients diagnosed with adenocarcinoma and esophageal SCC were evaluated between 2008 and 2014. 55 of these patients (16.6%) had adenocarcinoma and 276 (83.4%) had CPB, ranging from 38 to 92 years, mean age of 62.9 (+/- 9.8) years. Initially they underwent staging with CT and it was proposed a curative surgical management or palliative treatment. Lately they were evaluated with the inclusion of 18F-FDG-PET or PET-CT and then the final management was defined. Results: The proportion of positive lymph nodes (N +) on the CT scan was 71%, whereas in the metabolic methods it was 70.1% (p=0.834), however, with a fair agreement (Kappa=0.339). The proportion of metastases (M1) found in CT was 44.1% and in PET-CT, 47.1%. For metastases, the Kappa test showed that the two methods presented a moderate agreement (0.452), presenting staging changes in 36.5% of subjects, being 19.3% with upstaging and 17.2% with downstaging. However, only 63 patients (19%) showed changes in the final management and this was higher in upstaging patients (67,2%) (p < 0,005). In patients with Adenocarcinoma, a greater number of downstaging was observed (32.7%), compared to those with CPB (15.4%) (p < 0.0001), however, without any statistically significant difference when the change of management was evaluated. Evaluating individually the 140 patients staged with 18F-FDG-PET, 52.9% presented positive lymph nodes (N +), data similar to tomography (p = 0.053), however with fair agreement, about 32.9% of these had metastases (M1) (P=0.749) and with moderate agreement between the methods. After the staging, a conduct change of 23.6% occurred when evaluated by a multidisciplinary team. With the use of PET-CT, the proportion of T4 tumors was 27.2% (p = 0.071), but with good agreement with tomography (Kappa=0.616). The proportion of positive lymph nodes (N+) was 82.7%, with fair agreement with the tomography (Kappa=0.392). The proportion of metastases (M1) in PET-CT was 57.6%, with moderate agreement (Kappa=0.465). 34% of the individuals presented staging change, 19.3% with upstaging and 14.7% with downstaging. However, only 30 (15.7%) out of 191 presented a final change of behavior, 67.6% of which occurred in cases with upstaging when compared to cases with downstaging (17.9%) (p < 0.005). Patients with adenocarcinoma had a greater number of downstaging (30%) compared to those with CPB (11.8%), (p < 0.0001), however, with no statistically significant difference. Overall survival when staged with PET-CT was around 30% after 30 months, being similar both in the group of patients where there was change of management and in the group where this change of management did not occur. Conclusion: It was concluded that in the tomographic staging with 18F-FDG-PET and with PET-CT an expressive number of patients in advanced stages was identified, however these findings often differ from each other. The change in management occurs in an expressive number of patients, and usually in cases where upstaging occurs. Although Adenocarcinoma presents a greater number of cases of downstaging than CPB, this change in staging is not reflected in the change of management when both are compared. It is important, therefore, the multiprofessional evaluation in service of excellence when deciding on the best therapeutics. Finally, we observed the same survival curve between those patients in which there is certainty of the management to be taken and those in which the management was changed after the use of PET-CT, which corroborates with the need to use these two methods together

La Tomographie par Emission de Positons (TEP) au Fluoro-déoxyglucose marqué au Fluor 18 (¹⁸F-FDG), analogue du glucose, permet d'obtenir une image de la consommation de glucose dans l'organisme. La plupart des foyers tumoraux présentant une consommation excessive de glucose, son utilisation en oncologie permet d'améliorer la prise en charge des patients en diminuant le temps nécessaire pour évaluer l'efficacité des traitements tels que la chimiothérapie et la radiothérapie. Mon projet de recherche visait à proposer et améliorer des méthodes de quantification en TEP au ¹⁸F-FDG afin de caractériser au mieux l'évolution métabolique des volumes tumoraux.De nombreux facteurs biaisent la quantification en TEP. Parmi eux, l'Effet de Volume Partiel (EVP) reste difficile à corriger, notamment à cause de la faible résolution spatiale des images TEP. Afin de déterminer l'impact de la correction de l’EVP sur l’évaluation des réponses des tumeurs, une étude sur données simulées par Monte Carlo a tout d’abord été effectuée. Cette étude a été complétée par l’analyse de données TEP/TDM (Tomodensitométrie) acquises chez 40 patients atteints de cancers colorectaux métastatiques (CCM), traités par chimiothérapie à l'Institut Jules Bordet (Bruxelles). L’analyse de 101 tumeurs a montré que les critères tels que le SUV, n’incluant pas de correction de l'EVP, et qui reflètent alors le volume tumoral et son activité, prédisaient mieux l’évolution tumorale que les critères corrigés de l’EVP. Compte tenus des résultats prometteurs récents de méthodes de caractérisation de l’hétérogénéité de la fixation du FDG dans les tumeurs, un second volet de notre travail a consisté à étudier l’intérêt de la prise en compte de la texture dans le cadre du suivi thérapeutique. L’application de l’analyse de texture aux cas de CCM étudiés précédemment n’a pas permis de démontrer une valeur ajoutée des indices de texture par rapport aux index quantitatifs couramment employés en clinique. Nous avons montré que cette conclusion s’expliquait en partie par la non-robustesse des indices de texture vis-à-vis des paramètres impliqués dans leur mesure. Nous avons enfin cherché à évaluer une méthode d’Analyse Factorielle de Séquences d’Images Médicales (AFSIM), appliquée au contexte du suivi thérapeutique, pour caractériser l’évolution tumorale tout au long du traitement. Cette étude a porté sur 9 séries de 4 à 6 examens TEP/TDM de patients traités par radiothérapie au Centre Hospitalier Universitaire Henri Becquerel de Rouen. Outre l’information visuelle globale apportée par cette méthode, l’analyse quantitative des résultats obtenus a permis de caractériser l’hétérogénéité de la réponse vue par l’AFSIM. L’échec des index classiques, provenant entre autres de leur incapacité à distinguer les processus inflammatoires de l’activité métabolique tumorale, a permis de monter la valeur ajoutée de l’AFSIM par rapport aux index tels que le SUV maximal ou moyen. / Positron Emission Tomography (PET) using ¹⁸F-FluoroDeoxyGlucose (¹⁸F-FDG), a radiolabelled analogue of the glucose, is used to get an image of the glucose consumption in the body. As most tumor masses show a high glucose consumption, PET is widely used in oncology for diagnosis and patient monitoring. In the context of patient monitoring, the motivation is to decrease the time interval needed to assess treatment (radiotherapy or chemotherapy efficieny) compared to therapeutic follow-up based only on anatomic imaging only (Computed Tomography or Magnetic Resonance Imaging). My research project aimed at proposing and improving quantitative methods in FDG-PET to better characterize tumor evolution.In PET, many factors affect the accuracy of parameters estimated from the images. Among them, Partial Volume Effect (PVE) remains difficult to correct, mainly due to the low spatial resolution of PET images. To determine the impact of PVE on treatment response evaluation, a preliminary study was performed using Monte Carlo simulated PET scans. An additional study was conducted based on the analysis of the PET/CT (Computed Tomography) data of 40 Metastatic Colorectal Cancer (MCC) patients treated with chemotherapy at the Jules Bordet Institute (Brussels, Belgium). The analysis of the 101 tumors showed that criteria such as the Standardized Uptake Value (SUV), which does not include PVE correction, were better predictors of tumors evolutions than PVE corrected criteria. This is because without PVE correction, SUV includes information on both metabolic volume and metabolic activity, which are two relevant pieces of information to characterize the tumor. A second part of our work was to study the potential of tumor texture analysis in patient monitoring, following promising results reported in the literature. Texture analysis was applied to the MMC patients data previously mentioned but did allow to a better segregation of tumors responses as compared to indices currently used in the clinics. We found that this was partly due to the lack of robustness of the textures indices.Finally, we evaluated a Factor Analysis in Medical Images Series (FAMIS) method to characterize tumor evolution during treatment. This study focused on 9 series of 4 to 6 PET/CT scans acquired all along the radiotherapy/radio-chemotherapy of patients treated at the Centre Hospitalier Universitaire Henri Becquerel (Rouen, France). In addition to the rich visual information brought by this method, a quantitative analysis of the results made it possible to characterize response heterogeneity as seen using FAMIS. In particular, FAMIS clearly demonstrated the occurrence of inflammatory processes. In addition, due to the low metabolic activity of the tumors at the end of the treatment, many conventional indices could not describe the tumor changes, while FAMIS gave a full assessment of the tumor change over time.