Apport de l’imagerie hybride TEMP-TDM dans le suivi d’un cancer différencié de la thyroïde

In the management of patients with differentiated thyroid cancer (DTC), abnormalities detected on planar whole body scan and ¹³¹I-SPECT are difficult to interpret because of a lack of anatomical landmarks and limited specificity. Integrated ¹³¹I-SPECT-CT imaging has an additional value for characterization of equivocal tracer uptake seen on planar imaging as well as for precise localization. We illustrate through an observation the incremental diagnostic value of ¹³¹I-SPECT-CT images in the diagnosis of a cervical lymph node mimicking a physiological uptake on planar views. A 35-year-old Tunisian female was followed for papillary thyroid carcinoma, for which she underwent total thyroidectomy and iratherapy. Three years after a complete remission, the thyroglobulin (Tg) level on TSH stimulation increased. Diagnostic planar images with ¹³¹I did not disclose any obvious pathological foci. Furthermore, we noticed an increased ¹³¹I-uptake in the left sub-mandibulary area, which suggested a salivary physiological activity. SPECT-CT of the neck and chest were then performed with a Symbia T camera. Fused images demonstrate that this activity corresponds to a cervical lymph node closely adjacent to sub-mandibulary gland. Management of the patient was then changed. In selected patients with DTC, hybrid imaging should be used as a complementary to planar imaging in terms of diagnostic accuracy, because of superior focus localization and additional anatomic information derived from the CT component. Integrated SPECT-CT is then a useful tool, especially in cases of unclear diagnoses, precising anatomical localization of areas of increased ¹³¹I-uptake and distinguishing malignant lesions from normal physiological uptakes. This is particularly important in an oncologic center, as ours, where we don’t yet have a positron emission tomography (PET) camera is not yet available.     

Procédures de ventilation pulmonaire par aérosol Tc-DTPA : contamination aérienne, contaminations interne et cutanée externe des manipulateurs

Efficiency of an optimization procedure of radiation protection measures with lung ventilation by ^99mTc-DTPA aerosol was evaluated by measuring airborne radioactivity and by looking for external and internal contaminations of technologists. Despite numerous precautions, small amounts of radioactivity were airborne in 71.4% of procedures and a small internal contamination of technologists (1.6–881 Bq; median: 36.3 Bq) was found. The latter was highest in case of deficient patient collaboration and with technical incidents. A very low external contamination (0.1-29.1 Bq; median: 0.1 Bq) was demonstrated with 82% of procedures. Estimated effective doses by internal contamination (0.01-6.2 nSv; median 0.3 nSv) was minimal compared with the maximal legally admissible doses for professionally exposed workers (10 mSv/year); it does not represent an excessive irradiation risk.     

Gestion de la « crise du Mo » en 2010 par un service de médecine nucléaire hospitalier au Luxembourg : bilan

To face the challenges of the “⁹⁹Mo crisis” on a nuclear medicine department level, strategies were implemented to maintain numbers of scintigraphies as usual. We evaluated the efficiency of the measures. Using ^99mTc more rationally led to more profitable generator utilization. As long as the amount of ^99mTc at disposal (> 110%, 90–110% (= standard), 70–90%, 50–70%, 30–50% and < 30%) was greater than 30% of the standard, weekly numbers of ^99mTc-based investigations remained at “standard” level. Cost per mCi of administered ^99mTc remained unchanged. The successfully managed “⁹⁹Mo crisis” was based upon a rigorous organization as well as goodwill of all implicated staff, at the cost however of a lesser patient service. Punctual flexibility of staff members, adapted to the fluctuating work load, allowed global balance between numbers of required and delivered working hours. As efficient crisis management is tedious, generalization of the model cannot be thought of. To guarantee secure future availability of ^99mTc, projects for new nuclear reactors dedicated to producing ⁹⁹Mo are first choice.     

Étude de faisabilité du ganglion sentinelle dans le cancer de la prostate par cœlioscopie : premiers résultats

Objectives

The standard lymphadenectomy is currently a challenge in the management of prostate cancer. The aim of this prospective study was to evaluate the performance of the sentinel lymph node (SLN) by laparoscopy in patients with localized prostate cancer, candidates for local treatment.

Patients and methods

Patients were injected transrectal ultrasound-guided with 0.3 mL/100MBq 99^mTc-Sulfur rhenium colloid in each prostatic lobe, the day before surgery. Lymphoscintigraphy was performed after 2 hours. The detection was realized intraoperatively with a laparoscopic probe (Gamma Sup Clerad^®) followed by extensive dissection. Counts of SLN were performed in vivo and confirmed ex vivo. The histological analysis was performed by HPS staining and followed by immunochemistry if SLN was free.

Results

Seventy patients with carcinoma of the prostate at intermediate or high risk of lymph node metastases (D’Amico), PSA median 9.5 ng/mL [6–130], were included in the study. The lymphoscintigraphic detection rate was 94.2% (66/70) and intraoperative of 97.0% (68/70). Fourteen patients had lymph node metastases, six only in SLN. The false negative rate was 2/14 (14.0%). The internal iliac region is the first metastatic site (40.9%). Limited or standard lymph node dissection would have ignored respectively 72.7% and 59.0% of lymph node metastases.

Conclusion

The laparoscopy is adapted to a broad identification of SLN and targeted dissection of these lymph nodes significantly limits the risk of surgical extended dissection while maintaining the accuracy of the information.     

Introduction à l’étude du site de Longgupo

The site of Longgupo, discovered in 1984, is located south of the crossing of the Three Gorges of the Yangtze, in the eastern part of Chongqing Province. Situated on the limestone slope of the Miaoyu Valley, three excavation campaigns have been carried out since 1985. The first two seasons took place from 1985–1988 and 1997–1998, directed by W.B. Huang and the last campaign from 2003–2006 by E. Boëda and Y.M. Hou. After the first two campaigns, the presence of several bones, with an estimated age of 1.9 My, notably including a mandible fragment attributed to a hominid² and the discovery of more than 20 lithic artifacts incited not only great interest in the scientific community, but controversy as well since these data contradicted diffusion models of the first hominids out of Africa. Paleoanthropological data often being privileged over other data, including lithic artifacts, the anthropic nature of the site was contested. Yet the few artifacts from the initial excavations irrefutably demonstrate their manufacture by humans, in particular those in exogenous stone. To definitively re-establish the authenticity of this site by applying the latest investigative methods, a new Franco-Chinese campaign was organized. The objective of the 2003–2006 field seasons focused on understanding and analysis of the archaeological data in their geomorphological and stratigraphic contexts.     

Les derniers Homo heidelbergensis et leurs descendants les néandertaliens : datation des sites d’Orgnac 3, du Lazaret et de Zafarraya

This article presents the dating results recently obtained on three archaeological sites in Europe. At Orgnac 3 (Ardèche, France) from where the last Homo heidelbergensis fossils are associated with the first evidence of levallois technique, two speleothem formations from the 5b–6–7^th layers were U-Th dated with MC-ICPMS, giving an age range of 319–255 ka (2σ) (MIS 8–9), while the volcanic ash-bearing second layer was dated by ⁴⁰Ar/³⁹Ar, obtaining a preliminary date of 308.2 ± 6.8 ka (2σ). The combined ESR/U-Th dating of red deer enamel teeth from Lazaret cave (Alpes-Maritimes, France) attributed ages of 120–190 ka to the Acheulean and pre-Mousterian layers (MIS 6), which is in agreement with previous TIMS U-Th dates between 108 and 44 ka on calcite samples from the overlying TRA trench (MIS 5, 4, 3). At Zafarraya (Andalousie, Espagne), a number of ¹⁴C measurements on charcoal samples as well as combined ESR/U-Th dates on Capra and Equus dental enamels assigned the Mousterian artefacts and neandertalian fossils-bearing deposits an age interval between 42 and 34 ka (MIS 3).     

Valeur pronostique du curage ganglionnaire prophylactique dans le cancer différencié de la thyroïde

Objective

Although the efficacy of total thyroidectomy as the first step in differentiated thyroid cancer (DTC) management is well proven, it is always a matter of controversy whether prophylactic lymph node dissection improves prognosis and survival in DTC patients without suspicion of lymph node metastases either clinically or radiologically. The aim of this work is to study relapse rates in patients according to the initial presentation and type of surgery performed, in order to analyze the prognostic impact of lymph node dissection.

Patients and methods

One hundred and thirty patients with DTC were classified according to clinical presentation and type of surgery performed. They were monitored for six years to watch for recurrence.

Results

In patients with no clinical evident lymph nodes, the relapse rate was lower among patients who underwent total thyroidectomy in one step with prophylactic lymph node dissection.

Conclusion

Based on the results of other studies, and on our department experience of thyroid cancer management and monitoring, we strongly advocate careful and systematic exploration of the central lymph node compartments with exploration of the lateral side of the lesion if in doubt.     

Consolidation par Y-epratuzumab en fractionné dans le lymphome B diffus à grandes cellules : résultats préliminaires d’une étude de phase II

Purpose

A multicenter, non-randomized, on-going phase II study, promoted by the GOELAMS aims to evaluate the efficacy and safety of fractionated administration of ⁹⁰Y-epratuzumab (two injections 7 days apart) in consolidation therapy for patients older than 60 years with diffuse large B-cell lymphoma and large tumor mass who presented a complete response (CR), unconfirmed CR (uCR) or partial response (PR) after induction therapy with six courses of R-CHOP14. We report the preliminary results on 41 of the 75 enrolled patients.

Patients and method

Toxicity was evaluated according to NCI-CTC version 3. The CR and uCR rate and the rate of conversion of PR to CR/uCR 6 weeks after injections of ⁹⁰Y-epratuzumab were evaluated using IWRC criteria.

Results

Thirty-three patients received two injections of ⁹⁰Y-epratuzumab. The toxicity of ⁹⁰Y-epratuzumab was mainly hematologic, characterized by neutropenia grade 3/4 in 81.8% of patients and thrombocytopenia grade 3/4 in 78.8% of patients, reversible. Two patients (6.1%) had grade 3/4 non-hematologic toxicity. Six weeks after injection of ⁹⁰Y-epratuzumab, 40.0% of patients improved their response and the rate of CR/RCu was 83.9%.

Conclusion

These preliminary results show significant toxicity, but mainly hematologic, expected in consolidation. The response rate is encouraging and needs to be confirmed by sufficient number of inclusions and follow-up.     

Intérêt du dosage de la thyroglobulinémie chez les sujets porteurs du goitre en zones de déficience iodée au Bénin

In the present study, we analyze the results of thyroid hormones and thyroglobulinemia of 162 patients with goiter living in the departments of Collines and Donga, known to be areas of iodine deficiency in Benin. These results are compared with those of 85 healthy subjects living in the same departments. This study is a cross-sectional analytical study carried out from 1st July 2009 to 30th June 2010. The population of patients consisted of seven males and 155 females. The average age was of 45.7 years. Most of the patients were suffering of simple goiter. Only six of them had thyroid nodules. The diagnosis of biological hyperthyroidism was positive for 20 patients; 16 of them had subclinical hypothyroidism and four clinical hyperthyroidism. One case of clinical hypothyroidism was found. All other 141 patients were biologically normal (euthyroidism). Seventeen of the patients (including six patients presenting a thyroid nodule) had a normal thyroglobulin rate. Hyperthyroglobulinemia was observed in all other 145 patients. These results suggest that patients with goiter in zone of iodine deficiency are biologically euthyroid with hyper-thyroglobulinemia. Thyroglobulin dosage is then recommended, especially when nodules are perceptible.     

Impact d’une méthode originale de synchronisation respiratoire sur la détection des lésions hépatiques en TEP/TDM au F-FDG

In ¹⁸F-Fluoro-Desoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT), respiratory motion induces bias in image interpretations. These movements can introduce organs misregistration between both modalities yielding erroneous attenuation correction and thus wrong maximum standardized uptake values (SUV_max). We present here the results of a clinical study which aims to assess the benefits of a novel respiratory gating method (CT-based) for liver lesions detection. Forty-nine patients planed to undergo hepatic surgery were addressed to our department for PET/CT examination before surgery. Each patient had both standard and CT-based protocols. Hepatic lesions described by two observers on PET images were compared with pathological analysis and intra-operative ultrasound. Sensitivities calculated for observer 1 were 60 and 64% for standard and CT-based, respectively. For the second observer, sensitivities were 58.7 and 72%. CT-based showed a significant increase (P < 0.01) of sensitivity on a per-lesion basis for one observer. CT-based did not improve inter-observer variability. At last, SUV_max were significantly higher with CT-based method (P < 0.001). Respiratory gating CT-based method is easily bearable by the patients. This procedure ensures good matching between both modalities and reduces motion-blurring effect in PET data. CT-based method improves liver lesions detectability and allows more accurate quantitation compared to non-gated FDG-PET/CT examinations.     

Les récentes découvertes à Baerya dans le district de Bijie, au nord de la province de Guizhou (Chine)

Fauna associated with stone artifacts have recently been uncovered, in the course of a survey from a cave site named Baerya, town land of Bijie, Guizhou province. The first observations suggest a human occupation. In the absence of chrono-stratigraphic data, it is not possible to assess the age of the site. Nevertheless the presence of lower Pleistocene fauna suggests a very ancient age for this human occupation. Further field research will be necessary to determinate the age and nature of the site.     

Radiomarquage in vitro des leucocytes au [F]-fludésoxyglucose : première expérience à l’hôpital d’instruction des armées Val-de-Grâce

^99mTc-HMPAO (technetium^99m-hexamethylpropylene amine oxime) radiolabeled-leukocytes or Indium-111 oxine labeled leukocytes scintigraphy and positron emission tomography with [¹⁸F]-fludeoxyglucose (¹⁸F-FDG) are the reference techniques for infection imaging. These methods have some limits explaining the active research for an ideal infection tracer finding. Because of its potential advantages, leukocyte labeling with ¹⁸F-FDG have been developed but is not routinely used for clinical infection imaging. We report the results of our first experience of leukocyte radiolabeling with ¹⁸F-FDG, managed on 20 healthy subjects. Labeling efficiency, cellular viability and radiolabeling stability have been assessed. Our results exhibit the influence of different parameters on labeling efficiency: presence of glucose during the labeling reaction, number of cells and volumic activity of ¹⁸F-FDG. Stability assessment indicates that 60% of initial cellular activity persist in cells after 1 hour incubation. Our results are similar to literature data and permit us to consider a clinical use of radiolabeled leukocyte with ¹⁸F-FDG. Nevertheless, a clinical use of radiolabeled cells can’t be considered before the radiolabeling induced cellular effects have been assessed.     

Nouvelle approche de l’art rupestre de l’Atlas saharien : les figurations de la période tardive

Figurations in Atlas have been studied numerous times, namely by Flamand and Frobenius between 1891 and 1914, by Vaufrey in 1939 and by Lhote between 1955 and 1970. And finally there were Iliou’s¹ and Hachid’s theses in the 1980s and Amara’s thesis in 2001. The study of the Atlas figurations discovered since 1847 brought new data on the engravings from the recent period. The originality of the engravings lies in the appearance of new themes, which had been unknown until yet. The presence of metal weapons figures enriches the records of the Atlas rock Art. The alphabetical signs, another new theme, give an identity to this Art. The work undertaken in this vast region raises the problem of the persistency of the Neolithic culture. All the figurations show some aspects of the evolution, which become permanent, mostly at the end of the recent period.     

Le site de Longgupo dans son environnement géologique et géomorphologique

On a regional scale, Longgupo is found within a karstic landscape of fenglin-ouvala developed in the Triassic limestones of the Yangtze platform. After several seasons, it is now possible to define and propose a scenario for the formation of the site. During one of the intense karstification phases during the Cretaceous or early Tertiary, karstic conduits were created deep in the substratum. In concert with these deep flows and by karstic collapse, a cave was created. With the start of Himalayan uplift during the Oligocene and Miocene, the beginning of fluvial cutting was reflected by the partial erosion of the upper sandstone formations and the creation of the Miaoyu Valley. This action opened the cave, which would later be occupied by the hominid groups that interest us here. Probably at the end of the Tertiary, the cave, open at the bottom of the valley slope and facing upstream, began to be filled with alluvial deposits from the valley. The basal deposits (C III 10 of the current stratigraphic sequence, levels 20-13 of the first sequence) begin with black clays; at the Plio-Pleistocene transition, deposits become clearly alluvial, increasingly marked by reworking of surface and karstic clays and by systematically coarser contributions. During the deposition period of archaeological complexes III/III’ (previously levels 12-6), karstic collapse appears to have still been active. During the Lower Pleistocene sensu lato, the coarse nature of the deposits becomes accentuated. The material of complex II (previously levels 5-2) is a deposit that is clearly heterometric and coarse, composed at the end mainly of gravels, pebbles and more or less rounded blocks in a clayey matrix. At the conclusion of this new stage, the cave was entirely filled and, purely and simply, disappeared from the landscape. As the valley deepened during the Middle and Upper Pleistocene, the Longgupo slope underwent profound changes, the last of the limestone blocks disappeared from the slope limit and the archaeological site was protected by the coarse breccias that carpeted the slope. The main cause for the sedimentation processes at the site of Longgupo is the hydrosystem of the Miaoyu he, although injections of karstic type sensu stricto cannot be excluded. All of the arguments effectively support alluvial deposition: pebbles, an alternation of coarse and clayey beds, systematic and repeated granulometric decrease. But the stratigraphic disposition was disturbed by deformations due to gravity and karstic origins; the alluvial sediments, rendered plastic by the high proportion of clayey beds, were deformed by gravity (deformation of beds, faults, slopes) following the direction of the slope and by karstic collapse along the two limestone walls north and south of the sites (in sub-parallel faults to the south and by circular aspiration to the north). To this is added a calcitic consolidation of the upper levels that made it difficult to excavate complex C II. The stratigraphic disposition of the archaeological levels at Longgupo is now well understood. It has thus been possible to collect samples for absolute dating, to be published soon.     

Analyse des artefacts lithiques du site de Longgupo

Excavation has enabled recovery of 854 artifacts within 30 archaeological levels in the south sector and 11 in the north (chapter 3). These levels are quite probably contemporaneous, or even the same. The quantitative disparity in the number of strata between the two sectors is simply due to the fact that only the lower half of the northern zone was completely investigated. Similarly, the number of artifacts recovered by level varies according to the surface area excavated, although is some cases the density of material is significant despite the small area excavated, for example stratum C IV 5 which contains 174 lithic artifacts in 2 m². Before undertaking the technological analysis of the artifacts, given the preceding polemics provoked by the great age of this site and its implications for the spread of the first populations out of Africa, it was deemed important to carry out a plurifactorial analysis combining all of the data related to: the stratigraphy, taphonomic processes (post-depositional disturbance), analysis of natural processes that may have produced eoliths, experimentation and techno-functional analysis of the material. The stratigraphy shows clear interstratifications of fine and coarse fluviatile levels with often very clear particle size sorting of the coarse fraction. The archaeological material is typically found at the interface of these strata, either at the base of a clayey matrix, overlying a preceding coarse level, or in the superficial part of a sandy-clay deposit underlying coarse deposits. Post-depositional disturbance revealed during the new excavations in 2003–2006 cannot alone be the cause of eoliths. Excavation of a 6 m² zone in the modern river bed, located below the site, has demonstrated that the technological traits of eoliths recovered cannot in any way be confused with the technological traits of the artifacts recovered at the site itself. Similarly, viewed quantitatively, the 6 m² zone excavated in the river bed yielded around 20 eoliths while the 30 m² zone excavated at the site yielded 854 artifacts, one stratum alone yielding 184 artifacts in a 3 m² zone. During the experimental phase, adopting the same conditions of procuring raw material, from the same river bed, we very quickly realized the rarity of types of adequate volume that had been generally used at the site and the need to use certain operational processes to create such a form. In addition, the hardness and presence of several natural fracture planes in the Triassic limestone explain the choice of different operational processes and the very high number of knapping accidents, including those occurring during bipolar percussion. Although 90% of the raw material used was cobbles or broken blocks of local Triassic limestone, 10% of the tools were made on exogenous raw materials – siliceous or gravelly limestone, quartzitic sandstone, chert, volcanic rock – that are absent from the immediate environment of the site. These raw materials were brought to the site in the form of tools: worked cobbles, large retouched flakes, backed double-truncated flakes, a plaquette with a lateral bifacial edge, etc. The 854 artifacts have been classified into six object classes: worked cobbles with transversal edge (39%), worked cobbles with lateral edge (2%), unipolar flakes (27%), bipolar objects (half-blocks, half-cobbles including some flat “split” cobbles, “orange slices”, flakes and diverse fragments) (17%) and fragments resulting from knapping of blocks or cobbles (13%), hammerstone (2%). When the frequencies of these classes are calculated for each of the sectors, percentages are similar, indicating a high degree of homogeneity in the archaeological assemblages at the site. The situation is somewhat different when assemblages are compared within a single sector. Slight differences appear in the percentages of bipolar pieces and unipolar flakes. These differences seem to be random, like the frequency rate of knapping accidents in bipolar reduction, or economic, such as the choice of operational schemes to create worked cobbles based on the availability of suitable raw materials. The technological affinity between each of the archaeological assemblages tends to demonstrate great stability in technological knowledge through time. The class of worked cobbles is by far the most important and, apart from a few flakes produced intentionally, it appears to group all of the tools. To avoid placing these tools in a restrictive, semantically meaningless, class, we prefer the concept of matrix to the term worked cobble. A matrix is a structured arrangement of a series of technological traits, in a form as close as possible to that of the future tool. The matrix phase leads to the tool production phase, which may be unnecessary if the matrix phase includes fictionalization. In other words, the concept of matrix enables separating the phase of preparing a predetermined volume, such as a blade, Levallois flake or bifacial piece, from the tool production phase, consisting in creating the type of transformative edge intended, if necessary. The tool is thus an artifact of a specific form with an integrated edge and an operational scheme both specific to the function attributed to it and means of use associated with the form. Observed variability relates to: the size of the volume ranging from to 20, morphology, the form of the line formed by the edge which can in frontal view be curved, linear, sinuous or denticulated, and in transversal view curved, linear, sinuous or saw-toothed, and the length of the edge ranging from 1 to 10. Matrices with a simple bevel are distinguished from double bevels. In the framework of the technological analysis of production schemes to produce matrices with a simple bevel, a broad range of variability in production schemes can be observed, divided arbitrarily into two stages. The first stage consists in creating as closely as possibly the technological traits of the future matrix due to five general schemes. The first scheme (A) consists in selecting a cobble or block naturally possessing at least some of the technological traits needed. The missing traits are added by various preparations, including bipolar percussion 3 times out of 5. The second scheme (B) consists in knapping a flake from the block with some of the technological traits required for the matrix present on one of its surfaces. The third scheme (C) consists in the choice of a plaquette from which a bipolar shock creates the main traits of the matrix. The fourth scheme (D) consists in choosing a volume very similar to the intended matrix. The fifth and final scheme (E) consists in knapping a flake with technological traits very different from those intended. Depending on the distance between intention and realization, a second stage may be necessary. In general, this second stage perfects or creates the intended active edge, which is rarely obtained in the first stage. To produce a matrix with a double bevel, it is sometimes necessary to add an intermediate stage in order to prepare the second bevel. The first stage remains the same, with the use of the five operational schemes. By contrast, a clear difference exists in the percentages for the use of these schemes. For a matrix with a simple bevel, scheme A is dominant, followed by scheme D, while the situation is reversed for a matrix with a double bevel, where scheme D is dominant. Unipolar flakes, representing 27% of the assemblage, are produced in three different ways. The most important is flakes resulting from matrix production. The two others are flakes produced during different knapping schemes, some flakes in relation to the few cores present, other flakes in exogenous raw materials produced elsewhere and generally much larger. The other classes are dominated by bipolar products resulting essentially from knapping accidents. To summarize, these assemblages are characterized by: the search for tools differentiated by form and active edges; more than 90% of the tools made on two kinds of supports: a matrix with a simple bevel or a double bevel; matrices obtained using different operational schemes successively associating if necessary a knapping stage and a shaping stage. While the Triassic limestone is hard and thus imposes a strong constraint on knapping, the range of operational schemes appears to have been a “cultural” response diversified to this constraint and the presence of tools on exogenous raw materials. At the scale of China, comparison of this industry is impossible since it is the only site of this age and to contain so much material. The site of Majuangou, the only site of similar caliber, is younger by several hundred thousand years and is located several thousand kilometers to the north, making comparisons meaningless. We note only that most of the tool supports at Majuangou are knapped flakes. On an inter-continental scale, the comparison of sites of equal age is more promising. But lithic analyses are based on different methods, preventing comparison of similar data. However, if we make a simple summary of the data available, we can first say that in Africa, during these periods, different development technological stages were present and stages that are considered more evolved are manifestly less common using our approach. While these stages are more or less contemporaneous, which counters the idea of uniqueness, they would more surely be evidence of populations that were not in direct contact and had separate lines of development. In Asia, the Longgupo industry evidences a different technological option than that of contemporaneous populations in Africa. By contrast, when we take into account its developmental stage, we realize that this is an “evolved” stage in which the form of the support of the future tool is predominant. If we compare Africa and Asia in terms of stages, we are a priori at the same stage with different options being selected.     

Apport de deux techniques d’analyse automatisées des examens [F] FDG TEP dans la discrimination des patients déments frontotemporaux et malades d’Alzheimer

Introduction

In younger patients, the in vivo clinical diagnosis of Alzheimer's disease (AD) and of the frontotemporal type (FTD) may be cumbersome. The gold standard diagnostic proof is currently still based upon pathology examination. It is crucial to find reliable techniques to make an accurate in vivo diagnosis and to differentiate the etiology of the dementia.

Patients and method

Twenty-four patients bearing clinically diagnosed AD (n = 16) and FTD (n = 8) underwent [¹⁸F] FDG-PET/CT brain scan. Four nuclear medicine physicians with varying expertise in neuroimaging read each scan according to: visual analysis; automated analysis computed by BRASS^® Hermes^® software; automated analysis computed by Cortex ID^® General Electric^® software. Interpretation aimed at assessing the global scan aspect, the cerebral metabolism per hemisphere (in five relevant regions) and the diagnostic degree of confidence. Diagnostic interpretations derived from visual and automated analyses were compared to clinical diagnosis. Inter-observer agreement and Kappa scores were calculated.

Results

Kappa analyses showed a gain in diagnostic accuracy for a nonexpert physician, a gain in diagnostic confidence with Cortex ID^® and a gain in interobserver diagnostic agreement with BRASS^®.

Conclusion

Using automated software such as Cortex ID^® or BRASS^® helps standardizing the interpretation of [¹⁸F] FDG distribution pattern in AD or FTD.     

Products of CO2 fixation and 14C labelling pattern of alanine in Methanobacterium thermoautotrophicum pulse-labelled with 14CO2

The incorporation of ¹⁴CO₂ by an exponentially growing culture of the autotrophic bacterium Methanobacterium thermoautotrophicum has been studied. The distribution of radioactivity during 2s–120s incubation periods has been analyzed by chromatography and radioautography. After a 2 s incubation most of the radioactivity of the ethanolsoluble fraction was present in the amino acids alanine, glutamate, glutamine and aspartate, whereas phosphorylated compounds were only weakly labelled. The percentage of the total radioactivity fixed, which was contained in the principal early labelled amino acid alanine, increased in the first 20 s and only then decreased, indicating that alanine is derived from primary products of CO₂ fixation.The labelling patterns of alanine produced during various incubation times have been determined by degradation. After a 2 s ¹⁴CO₂ pulse, 61% of the radioactivity was located in C-1, 23% in C-2, and 16% in C-3. The results are consistent with the operation of a previously proposed autotrophic CO₂ assimilation pathway which involves the formation of acetyl CoA from 2 CO₂ via one-carbon unit intermediates, followed by the reductive carboxylation of acetyl CoA to pyruvate.     

Une radiothérapie interne contre l’infection au VIH, la dernière pièce du puzzle ?

Although highly active antiretroviral therapy (HAART) has succeeded in many cases in suppressing ongoing viral replication, the HIV-infected cells are not eradicated by this therapy. In this article, the author proposes a new treatment protocol based on administration of radiophosphorus 32 (³²P) with HAART combination. The proposed new protocol consists of the following steps: HAART keeps viral replication below the level of detection. Then, ³²P is administered for the removal of the “residual disease”. By its beta emission, incorporated ³²P to viral RNA or proviral DNA may kill free virions and productively infected cells, reactivates latently infected cells and makes them vulnerable to immune competent cells and antiretroviral therapy. This new combination may exhibit synergistic interactions between virostatic effects of antiretroviral molecules and radiobiological effect of internal radiotherapy and provide a new tool to purge the viral reservoirs.     

Trilobites Asteropyginae dévoniens d’Iran

Ten species of trilobites belonging to 4 genera of the sub-family Asteropyginae DELO are described from the Devonian (Givetian-Frasnian) of Iran. Three of which are new: Neocalmonia lutensis nov. sp., Neocalmonia yazdii nov. sp. and Radiopyge sardarensis nov. sp. The study of this material have required the revision of Heliopyge sharudensis(PILLET, 1974) from the Givetian of the Eastern Alborz Mountains and of Neocalmonia quadricosta PILLET, 1969, type-species of the genus Neocalmonia, from the Frasnian of Afghanistan. The recognition of genera and species in common with the Givetian and the Frasnian of Afghanistan emphasizes the close relations between these two regions. The genera Bradocryphaeus, Heliopyge, Neocalmonia, Radiopyge, represented by related species, are likewise present in Iran, Afghanistan and Western Europe. Their presence confirms that these regions belong, during the Devonian, to the North Gondwanian domain.     

Caméras hybrides TEMP-TDM et semi-quantification du I-FPCIT : évaluation de l’apport de la TDM

Objectives

Tomoscintigraphy of dopamine transporters with ¹²³I-FP-CIT is nowadays essential to visualise impairment of nigro-striatal system for the diagnosis of parkinsonism and for the differential diagnosis of dementia. With the development of hybrid cameras (SPECT-CT), the CT contribution in nuclear neurology needs to be assessed in diagnostic and semi-quantification performances. The main purpose of our study is to compare attenuation correction using CT to attenuation correction using the linear algorithm of Chang. SPECT-CT with parallel collimation results were also weighed against fan beam collimation and the contribution of partial volume effect correction was studied in secondary objective.

Materials and methods

We used a trilinear phantom to define spatial resolution and an anthropomorphic striatal phantom to quantify the activity in striatal cavities. We compared the impact of attenuation and scatter correction on spatial resolution and semi-quantification in striatum. We performed the partial volume effect correction on reconstructed images according to the method of Rousset.

Results

Attenuation correction by CT did not improve significantly spatial resolution compared to the algorithm of Chang. The semi-quantification of ¹²³I-FPCIT in striata was not significantly different according to the various CA, but was significantly improved with CT attenuation and scatter correction. Partial volume effect correction improved the quantification from 40 to 60% in the striatal structures, when the activity was superior in at least twice the background noise.

Conclusion

SPECT-CT hybrid cameras increase spatial resolution and improve semi-quantification of ¹²³I-FPCIT because of CT attenuation and scatter correction. Another use of CT is the possibility of calibrating anatomic segmentation of striata for partial volume effect correction. Partial volume effect correction improves quantification and is essential for early diagnosis of nigro-striatal disease.