Psammocarcinome ovarien et médecine nucléaire

We report three cases of ovarian psammocarcinoma, which is a serous adenocarcinoma having psammoma calcifications. The FDG uptake in the psammomatous lesions is due to the tissular part of the lesion and the technetium-99m labelled agents uptake to its calcified part. Calcifications are detected on CT scans. Therefore, they are relatively simple to diagnose by nuclear medicine which is useful given relatively the better prognosis of the psammomatous ovarian serous carcinoma when compared to the serous one.     

Une méthode d'amplification génique isotherme

A gene amplification technique applied to the detection of HIV and which can be implemented without programmable thermocyclers is described. The reaction products are high molecular weight strands of DNA that can be detected using simple methods, even without electrophoresis. This is a promising technique for in situ amplification experiments. Our findings show that this amplification method is compatible with the temperature levels encountered in living cells. This technology could thus be the basis for a new class of drugs intended for treatment by gene therapy of certain diseases, including malaria and AIDS.     

Comparaison de deux méthodes de mesure des TLG en TEP au 18-FDG dans le mélanome métastatique

IntroductionThere are many automated segmentation softwares in PET-CT, but none of them is used as gold standard. The aim of this study is to compare two segmentation softwares, one based on maximum intensity projection (MIP-based) and the second: PETVCAR^®, to measure TLG in patients with metastatic melanoma treated by vemurafenib.Materials and methodsSixteen patients were assessed by PET using 18-fluorodesoxyglucose (18-FDG) before and during the treatment with vemurafenib. TLG were measured by MIP-based and PETVCAR^® and then analysed in initial PET, all PET, by organ and added for each PET.ResultsThere is a good correlation between TLG in each method (r = 0.96 with P = 0 on 439 lesions on all PET). The mean difference between TLG PETVCAR^® and TLG MIP-based is negative. Segmentations are larger with MIP-based than with PETVCAR^® with discrepancies observed for larger and heterogeneous lesions. SUV_max doesn’t seem to be the factor causing these discrepancies. Correlation between the difference of TLG and their mean is also strong especially in bones, nodes and subcutaneous lesions.ConclusionBoth methods have a good correlation in spite of discrepancies observed for large or heterogeneous lesions. These lesions segmentations are larger with the method based on MIP than with PETVCAR^®.     

Mode d'action et propriétés des facteurs inducteurs issus du mésenchyme gastrique et des mésenchymes hétérologues

Résumé Des expériences d'associations d'épithélium gastrique de foetus de Lapin et de mésenchyme homologue ou hétérologue, partielles ou par membrane filtrante interposée, mettent en évidence l'existence de deux types de facteurs inducteurs.Le premier facteur induit la morphogenèse de l'épithélium. Il est thermostable et hautement diffusible.Le deuxième facteur, organospécifique, est plus ou moins favorable à la différenciation de l'épithélium gastrique suivant la nature du mésenchyme. Faiblement diffusible et thermolabile, il est élaboré dans la phase cytoplasmique des cellules mésenchymateuses.

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Action and properties of inductive factors proceeding from gastric and heterologous mesenchymes

Summary Experimental associations of gastric epithelium of the Rabbit foetus with homologous or heterologous mesenchyme, separated by membrane filter or partially associated, permit us to prove the existence of two types of inductors.The first factor induces the epithelial morphogenesis. It is thermostable and highly diffusible.The second factor, organospecific, is more or less favorable to the differentiation of the gastric epithelium according to the nature of the mesenchyme. Lightly diffusible and thermolabile, it is elaborated in the cytoplasmic phase of the mesenchymal cells.

     

Les essais cliniques en médecine nucléaire

The EU clinical trials directive (2001/20/EC) was published on the 4th April 2001 and was transposed into French law in 2004. This new clinical trial regulation has modified considerably the research area including clinical trials conducted with radiopharmaceutical medicinal products. This new regulation aims at ensuring the protection of the health and safety of clinical trial participants, the ethical soundness and the reliability and robustness of data generated in clinical trials. In practice, the sponsor has to submit a clinical trial application to the Afssaps for authorization and to the concerned Ethics Committee for a positive opinion. The content of the clinical trial application regarding the investigational medicinal product is very detailed and a heavy technical dossier could be required in order to justify the quality of the medicinal product used in the clinical trial. Furthermore, pharmacy and radiopharmacy required specific authorizations for preparing these medicinal products. This new regulation could refrain nuclear medicine from conducting clinical trials.     

Réflexions sur la place des médecins spécialistes en médecine nucléaire dans le dispositif d’annonce en cancérologie

Nuclear medicine physicians are very involved in French's oncology announcement procedure. However, their role needs to be analysed and evaluated. Before diagnosis’ announcement, information provided by nuclear medicine physicians are never neutral for patients. Information must not increase patient's anxiety or false patient's sense of reassurance. In this context, it seems necessary to engage in ethical reflexions about nuclear medicine physicians communication challenges.     

Comparaison de différents indices métaboliques et de la méthode SULTAN dans l’évaluation de la réponse thérapeutique par TEP au 18FDG dans le cancer du sein métastatique

Objective18F-FDG PET is a valuable tool in the evaluation of therapeutic response in breast cancer. This retrospective study was designed to compare the performance of six metabolic indices and to define their optimal thresholds, in patients treated with chemotherapy or hormone therapy for metastatic breast cancer. The performances of a parametric analysis by SULTAN method were also evaluated.MethodsTwenty patients, who underwent from 2 to 7 PET during the follow-up were analyzed. For each target, six indices were measured: SUVmax (maximum Standardized Uptake Value), SUVpeak, SAM (Standardized Added Metabolic activity), metabolic volume (MV), SUVmean using an adaptive threshold, and TLG (total lesion glycolysis). The percentage change of each target between each PET was calculated. A method based on parametric imaging (SULTAN) was also applied to each patient. The results were compared to the gold standard, defined by clinical evaluation, biological and morphological imaging RECIST 1.1 criteria. A per-lesion and per-patient analysis were performed and the optimal thresholds for each indices were calculated.ResultsFor the per-lesion analysis, 61 targets and 111 evolutions with 67 responders (R) and 44 non-responders (NR) were studied. Using ROC curve analysis and intercomparison, SUVmax, SUVpeak and SUVmean were significantly better than SAM, TLG and VM (P < 0.05). Using the optimal thresholds of −21%, –21%, –34%, –48% and –23% for SUVmax, SUVpeak, SUVmean, SAM and TLG respectively, these five indices were significantly correlated with the gold standard. SUVmax, SUVpeak and SUVmean showed the best performances of sensitivity (88%, 87% and 78% respectively), specificity (93%, 93% and 98% respectively) and negative predictive value (NPV) (84%, 69% and 74% respectively). For the per-patient analysis, 42 pairs of PET with 22 R and 20 NR were studied. Only SUVmax and SUVpeak were correlated to gold standard with the 30%-PERCIST-threshold and with optimal thresholds with performances of sensitivity of 73% and 77%, specificity of 95% and NPV of 76% and 79%. Parametric analysis with SULTAN showed excellent performances in the per-lesion and per-patient analysis (sensitivity 84% and 82%, specificity 98% and 90%, NPV 80% and 82%, respectively).ConclusionSUVmax and SUVpeak appeared the best indices to evaluate metabolic response in metastatic breast cancer. The SULTAN method was a reliable method to assist interpretation.     

Croissance et développement deCystoseira (Phaeophycea-Fucales) méditerranéens

Resume 1. Comparaison du comportement et de l'évolution au cours d'une année de quelques pieds âgés et de quelques embryons deCystoseira méditerranéens (principalementC. mediterranea Sauvageau 1912) cultivés parallèlement d'une part en pleine mer, d'autre part au laboratoire en milieu artificiel ou en aquarium.2. En pleine mer, l'évolution des échantillons âgés se déroule normalement. En aquarium, la chute des rameaux de printemps et la formation des rameaux d'automne sont d'autant plus précoces que l'éclairement est plus faible.3. Le développement et la croissance des embryons sont à peu près semblables en mer et au laboratoire, mais les «feuilles» caractéristiques apparaissent beaucoup plus tôt sur les individus cultivés en milieu artificiel. Les jeunes plantules nées en automne évoluent beaucoup plus rapidement que les plantules de printemps.

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Wachstum und Entwicklung mediterraner Cystoseiren (Phaeophyceae-Fucales). Kulturversuche im Meer

Kurzfassung Etwa ein Jahr lang wurde die Entwicklung mediterranerCystoseira-Arten (hauptsächlich vonC. mediterranea) verglichen, die im freien Meer und im Aquarium bzw. im Laboratorium aufwuchsen. Es zeigte sich, daß Pflanzen vom natürlichen Standort auf dem Versuchsstand im freien Meer normal weitergediehen. Im Aquarium treiben — vermutlich wegen des schwächeren Lichtgenusses — die Frühjahrssprosse zeitiger aus, und die Herbstzweige erscheinen früher. Aus Eiern kultivierte Keimlinge entwickeln sich in künstlichen Nährmedien zunächst schneller, doch gleicht sich der Größenunterschied nach dem Umsetzen in das Meer oder Aquarium nach 6 Monaten aus. Die charakteristischen Blätter erschienen aber bei den im Laboratorium kultivierten Pflanzen früher als bei den Vergleichspflanzen im Meer. In einer Aufzucht aus Herbsteiern erscheinen die Blätter bereits im Februar, also zur gleichen Zeit wie bei den um ein halbes Jahr älteren Kulturen.

     

La simulation Monte Carlo en médecine nucléaire

The Monte Carlo method allows for simulating random processes by using series of pseudo-random numbers. It became an important tool in nuclear medicine to assist in the design of new medical imaging devices, optimise their use and analyse their data. Presently, the sophistication of the simulation tools allows the introduction of Monte Carlo predictions in data correction and image reconstruction processes. The availability to simulate time dependent processes opens up new horizons for Monte Carlo simulation in nuclear medicine. In a near future, these developments will allow to tackle simultaneously imaging and dosimetry issues and soon, case system Monte Carlo simulations may become part of the nuclear medicine diagnostic process. This paper describes some Monte Carlo method basics and the sampling methods that were developed for it. It gives a referenced list of different simulation software used in nuclear medicine and enumerates some of their present and prospective applications.     

Métastase splénique isolée métachrone d’un adénocarcinome colique

Isolated splenic metastases of colorectal cancers are very rare but possible even after several years of remission. We report the case of a 74-year-old man who developed isolated metachronous splenic metastasis of left colon cancer 5 years after the treatment of the primary tumor. Splenic metastasis was found by imaging examinations. The patient underwent splenectomy and the histological examination confirmed the metastatic nature of the splenic lesion. 18F-FDG PET allows both staging and resectability of these isolated metachronous splenic metastasis because a long-term survival can be achieved by splenectomy.