Intérêt de l’imagerie hybride TEMP/TDM pour la scintigraphie des récepteurs de la somatostatine dans le bilan des tumeurs endocrines gastro-entéro-pancréatiques

In this work, we have evaluated the potential of image fusion and attenuation correction (AC) of SPECT-CT imaging for the assessment of gastro-entero-pancreatic endocrine tumors by somatostatin receptor scintigraphy (SRS).MethodAfter optimisation of acquisition and reconstruction parameters, we have evaluated, in a prospective study, SRS performed over a period of one year. We have compared visual interpretations of planar and tomographic images versus SPECT/CT images to determine if anatomical localisation and diagnostic contributions are improved. In a semi-quantitative analysis of pathological foci, we have measured maximal intensity values (T_max), tumour to background ratios (T/B) and tumour contrasts (Ct) with and without AC.ResultsIn 25 SRS, visual analysis has shown anatomical localisation improvements in 60% of cases (CI95%, 39–79) and diagnostic improvements in 64% of cases (CI95%, 43–82). Doubtful foci proportion changed from 44 to 11%. In the semi-quantitative analysis of 41 pathological foci, Wilcoxon matched-pairs tests showed significantly higher T_max, T/B and Ct values after AC.ConclusionSPECT/CT imaging improves diagnostic quality of SRS thanks to a better foci localisation and a better lesional contrast in the image.     

Y a t-il encore de la place pour la scintigraphie conventionnelle aux récepteurs de la somatostatine dans les tumeurs carcinoïdes à l’ère de la TEP ?

Our aim is to discuss, based on literature data, whether or not there is still a place for conventional somatostatin receptor scintigraphy (C-SRS) in the exploration of carcinoid tumours (CT) in the era of PET.MethodsBibliography was obtained by an interrogation of database: PubMed and Cochrane for the last 10 years. Keywords used were “neuroendocrine tumors”, “carcinoid tumors”, “pentetreotide”, “somatostatin”, “gallium-68” and “indium-111”.ResultsC-SRS visualized local or distant metastasis, with a sensitivity reaching 90% when size lesion is greater than 1 cm. It was more sensitive than morphologic exams in the detection of the primary lesion as well as the metastases and recurrent lesions. C-SRS had modified the therapeutic strategy in 21 to 53% of patients. It had determined resecability criteria and had predicted somatostatin analogue treatment efficiency. Furthermore, C-SRS was very useful in the follow-up of these tumours, mainly in the early detection of postoperative residues and recurrence. Recently, ⁶⁸Ga-DOTA-TOC PET had been used in some centers. According to many authors, it was superior to C-SRS for the detection of CT localization in the lung and skeleton and was similar for the detection of CT localization in liver and brain. According to these authors, ⁶⁸Ga-DOTA-TOC PET had evidenced lesions than C-SRS; nevertheless, there is always a global similar sensitivity in carcinoid tumours.Conclusion⁶⁸Ga-DOTA-TOC PET is surely more advantageous in guiding clinical management and follow-up, yet this imaging modality is expensive and not widespread. Nevertheless, C-SRS, which is cheaper, is an accurate technique in carcinoid tumours. Furthermore, if C-SRS proves negative, ⁶⁸Ga-DOTA-TOC PET should be indicated.     

L’imagerie moléculaire de la démence : quels moyens pour répondre à quelles questions ?

Molecular imaging might address two different aspects of dementia management: the early and etiologic diagnosis of the neurodegenerative disease causing the troubles, and the follow-up and treatment evaluation of the disease. Tracers available for these different purposes target either specific processes, such as the presence of beta amyloid in the case of Alzheimer disease, or processes that relate to the global functional state of the brain. Benefits and disadvantages of these different tracers vary according to the function of the goals pursued.     

Radiothérapie métabolique dans les tumeurs neuroendocrines par le DOTATATE marqué au lutétium 177 : expérience libanaise à propos de 6 cas avec revue de la littérature

The prevalence of neuroendocrine tumors (NET) is rare. Although some aggressive forms may exist, most NET shows a slow growth. The diagnosis is frequently made at a metastatic stage with more than 50% of hepatic metastasis. The only curative treatment is radical surgery and the other non-surgical therapeutic choices are chemotherapy, hepatic chemoembolization, alpha interferon, cold or non-radioactive somatostatin analogues and, more recently introduced, metabolic or internal radiotherapy with a somatostatin analogue coupled to an appropriate radioisotope. Nowadays, imagining of NET with a 68Ga-DOTATATE PET allows obtaining a better image quality and an effective dosimetry before treating with a somatostatin analogue coupled to an appropriate radioisotope such as 177Lu-DOTATATE. This latter can stabilize a rapidly progressive disease and improve quality of life enough and change it deeply. We are presenting our Lebanese experience by reporting six cases treated with 177Lu-DOTATATE after a PET/CT 68Ga-DOTATATE, and a review of literature.     

À propos d’une fixation de l’uncus du pancréas à la scintigraphie des récepteurs de la somatostatine

We report a case of increased Indium 111 pentetreotide (Octreoscan^®) uptake in the processus incinatus of pancreas. 68 Gallium somatostatin analog radiotracer uptake in the head of the pancreas is a common finding, however, this pitfall has never been described with Indium 111 pentetreotide SPECT.     

Étude de l’expression de LAT-1 et de la fixation de la 18F-FDOPA dans les tumeurs cérébrales. Illustration par une série de cas

IntroductionPET imaging of amino acid analogues, in particular with ¹⁸F-FDOPA, is increasingly used for the diagnosis and post-therapeutic evaluation of brain tumors. The mechanism of ¹⁸F-FDOPA uptake in brain tumors is still debated in the literature, the main hypothesis being uptake via L-amino-transporter 1 (LAT-1).MethodWe present 4 cases of patients with primary or secondary brain lesions who underwent ¹⁸F-FDOPA PET/CT or PET/MRI for the evaluation of suspected tumor recurrence and who underwent surgical removal with immunostaining labeling of LAT-1 transporters within 3 months. For each of these patients, a correspondence between semi-quantitative PET parameters (SUVmax, TBRmax and TSRmax) and anatomopathological characteristics was performed.ResultsAll patients had a significant and intense tumor uptake on ¹⁸F-FDOPA PET. In contrast, the expression level of LAT-1 receptors was very variable from one patient to another (LAT-1 score ranging from 0 to 193).ConclusionThis article reflects the persistent questioning of the link between the LAT-1 receptor and the uptake intensity on ¹⁸F-FDOPA PET, especially in patients who have received a first line of treatment.     

Sur les transports de réserves et les transports de couvain dans la ruche

Résumé Dans cet exposé, nous avons montré que les Abeilles sont capables de changer de place les réserves sucrées et le couvain. Ces comportements ne correspondent pas à des conditions de vie normales de la colonie.Cependant, le transport des réserves indique la possibilité, pour les Abeilles, de réagir à une perturbation importante selon un ordre que nous avions déjà établi dans l'élevage des larves (Montagner, 1962). C'est ainsi qu'en cas de nourrissement brutal et pendant une période de disette, elles tendent à grouper la majeure partie des réserves près de la reine, tout en laissant une place sur un cadre pour la ponte. La reine représenterait donc bien, dans la ruche, le potentiel survie à partir duquel les ouvrières auraient tendance à répartir leurs activités de façon décroissante.Par contre, les transports de couvain ne semblent répondre à aucun plan d'organisation comme chez les Fourmis. Nous avons montré qu'ils étaient associés à de profondes perturbations, telles que le manque de nourriture ou la perte de la reine.

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Summary The results of these studies indicate that bees are able to remove sugary stores and brood.We have established that bees remove their stores according to a certain order that we also made evident when studying brood rearing (Montagner, 1962). So, the bees hoarded the most part of their stores in the side of the hive where the queen stood, when we fed them suddenly during a dearth time.Then, the queen would be in beehive the attractive center from which the workers would share theirs activities in a decreasing way.On the contrary, it never seemed to us that the removals of brood were connected to any right order as for ants. We have established that they were associated to great troubles in beehive such as a want of food or the death of the queen.

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Zusammenfassung In diesem Bericht haben wir bewiesen, dass die Bienen die Zuckervorräte und die Brut an andere Plätze zu bringen vermögen. Dieses Verhalten entspricht nich den normalen Lebenszuständen der Kolonie.Soch bezeugt der Transport der Vorräte die Möglichkeit für die Bienen, gegen eine erhebliche Störung, nach einer bestimmten Regel zu reagieren, die wir schon bei der Aufzucht der Larven festgestellt haben (Montagner, 1962).Also, im Falle einer plötzlich verstärkten Zufuhr und während einer Mangelperiode haben sie die Neigung, den grössten Teil der Vorräte um die Königin zu sammeln, indem sie aber einen Platz für das Eierlegen auf einem Rahmen frei lassen. Die Königin würde also im Bienenstock die Möglichkeit der Fortdauer darstellen. Von dieser Tatsache ausgehend würden die Arbeiterinnen also ihre Tätigkeit in abnehmender Weise ausüben.Im Gegenteil scheinen die Brutversetzungen keinem Organisationsplan zu entsprechen, wie es bei den Ameisen der Fall ist. Wir haben gezeigt, dass sie mit schwerwiegenden Störungen, wie z. B. dem Nahrungsmangel oder dem Tod der Königin, in Verbindung stehen.

     

A propos de l'intervention des aéroions dans les processus de régulation de la lipémie et de la cholestérolémie

Resume Les expériences ont porté sur des lapins repartis en deux groupes parallèles — un groupe étant traité avec des aéroions négatifs en concentrations moderées (n^– = 10 – 40.000; n⁺ = 1.000) et l'autre sans aéroionothérapie (témoins). Par rapport aux animaux témoins (pas exposés aux aéroions),on a enregistré,sous l'influence de l'aéroionothérapie, que: (1)il y a une tendence de normalisation de la motilité spontanée, deprimée par une alimentation contenant un excès de cholestérol(0,3 g/kg/jour); (2) la lipémie et la cholestérolémie sont restées à un niveau plus bas chez les animaux alimentés au cholestérol; (3) la lipémie et la cholestérolémie, de même que l'iode thyroïdien, sont restées aux valeurs voisines de celles normales,chez les animaux nourris avec un excès (20 mg/kg/jour), de substances antithyroïdiennes naturelles (provenant du chou).

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Groups of rabbits were exposed to negative air ions of moderate concentrations (n^– = 10 – 40,000; n⁺ = 1,000) while others served as controls. (1) When rabbits were fed a cholesterol-rich diet (0.3 g/kg/day)causing reduction of motility in the control animals, their motility was normalized under air ion treatment. (2) The blood cholesterol and lipid levels of rabbits on a cholesterol-rich diet were lower with air ion treatment than in controls.(3) When rabbits were fed a diet with thyroid blocking agents from cabbage the blood cholesterol and lipid levels and the thyroid iodine content remained unchanged with air ion treatment.

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Zusammenfassung Gruppen Kaninchen wurden mit negativen Luftionen in mässigen Konzentrationen (n^– = 100 000 – 40 000; n⁺ = 1 000) behandelt, während andere als Kontrollen dienten. (1) Die durch Fütterung von cholesterinreicher Diät (0,3 g/kg/Tag) verminderte Motilität der Tiere wurde unter der Luftionenbehandlung normalisiert. (2) Der durch Fütterung von cholesterinreicher Diät erhöhte Blutcholesterin- und-fettspiegel fiel durch Luftionenbehandlung ab. (3) Der durch Fütterung von strumipriven Substanzen aus Kohl erhöhte Cholesterin- und Fettspiegel im Blut und verminderte Jodgehalt der Schilddrüse wurde durch Luftionenbehandlung nicht beeinflusst.

     

Effets de la fluorescence résiduelle dans les tissus biologiques sur les signaux de fluorescence résolus temporellement par la méthode des éléments finis

A computational model based on finite element method is derived to examine how the simulated time-dependent signals are related to the presence of residual fluorescence in biological media surrounding a fluorescent object. We apply a subtraction technique on recorded data when imperfect uptake of fluorescing agent into the tumor is considered. We show the limits of the subtracting method for low target: background fluorescent absorption contrast by extracting the time to reach the half maximum and analyzing the maximum of the time-resolved signals versus target depth.     

État des lieux des organisations de la prise en charge psychologique dans les réseaux et recommandations de la SFPO

In 2007, the SFPO (French Psycho-Oncological Society) created a Care Network Commission, which was to conduct a two-year survey regarding the organization of psychological management within 148 oncology and palliative care networks in France. The results demonstrate the need for trained psychologists. We here present some of the SFPO recommendations on this topic.