Intérêt de l’imagerie hybride TEMP-TDM pour la détection du ganglion sentinelle dans les cancers du sein

IntroductionSingle-Photon Emission Computed Tomography-Computed Tomography (SPECT-CT) is an hybrid technique which associates functional and morphological images. The aim of this study was to assess the role of SPECT-CT lymphoscintigraphy in sentinel node identification in patients with breast cancer.MethodsTwelve months prospective study was undertaken. Lymphoscintigraphy comprising planar and SPECT-CT acquisition was performed in 51 consecutive patients with breast cancer (mean age: 62 ± 11.3, range: 33–83 years). Planar and SPECT-CT images were interpreted separately and the two imaging techniques were compared with respect to their ability to identify sentinel node.ResultsAn add-value of SPECT-CT images was evidenced in 31% of cases: a more accurate anatomic localization in 21% of cases and identification of undeterminate sites of uptake in 10% of cases. Furthermore, SPECT-CT detected intramammary (4% of cases) and retromammary (2% of cases) sentinel nodes missed by planar imaging. SPECT-CT was more sensitive for internal mammary drainage detection (6% of cases). The added value proved higher in obese patients. Finally, functional and anatomical images fusion and three-dimensional overview provided clear and readily usable informations to the surgeon.ConclusionHybrid SPECT-CT imaging improves the preoperative localisation of sentinel nodes in patients with breast cancer, in particular in obese patients. SPECT-CT provides readily usable informations to the surgeon.     

L’apport de l’imagerie hybride TEMP/TDM dans la prise en charge du cancer différencié de la thyroïde

IntroductionSingle photon emission computed tomography combined with a low dose computed tomography (SPECT/CT), is a hybrid imaging integrating functional and anatomical data. The purpose of our study was to evaluate the contribution of the SPECT/CT over traditional planar imaging of patients with differentiated thyroid carcinoma (DTC).MethodsPost-therapy iodine 131 (¹³¹I) whole-body scan followed by cervico-thoracic SPECT/CT, were performed in 100 patients with DTC.ResultsAmong these 100 patients followed for a predominantly papillary DTC, planar imaging and SPECT/CT, were perfectly concordant in 70% of patients and discordant in the remaining 30%. The use of fusion imaging SPECT/CT compared to conventional planar imaging allowed us to correct our therapeutic approach in 27% (27/100 patients), according to the protocols of therapeutic management of our institute.ConclusionSPECT/CT is a hybrid imaging modality which provides better identification and more correct anatomic localization of the foci of radioiodine uptake with impact on therapeutic management.     

Pathologie extrapyramidale : apport diagnostique de l’imagerie fonctionnelle et morphologique

Imaging of dopamine transporter (DatScan^®) confirms the existence of a presynaptic dopaminergic denervation in parkinsonian degenerative syndromes: Parkinson's disease, multiple system atrophy and progressive supranuclear palsy. It helps to differentiate these diseases from parkinsonian syndromes without involvement of the presynaptic nigrostriatal pathway (drug-induced, psychogenic and sometimes vascular) or atypical tremor. This imagery also contributes to the diagnosis of dementia with Lewy bodies where there is a decrease in binding of this tracer. On the contrary it is not useful for differentiating Parkinson's disease from other degenerative parkinsonian syndromes. The study of post-synaptic dopaminergic system, which is not yet available in routine, could facilitate the distinction between these degenerative parkinsonian syndromes, as well as MIBG-I123 myocardial scintigraphy; MRI morphology revealed in these pathologies signal abnormalities within the basal ganglia and brainstem structures.     

Apport de la TEMP/TDM pour la détection du ganglion sentinelle dans les cancers du col utérin et de l’endomètre

The sentinel lymph node procedure is still under evaluation for the management of cervical and endometrial carcinomas. The aim of our study was to determine the diagnostic accuracy of single-photon emission computed tomography/computed tomography (SPECT/CT) for preoperative sentinel lymph node mapping in uterine cancers. Sixty-eight patients with cervical (n = 42) or endometrial carcinoma (n = 26) underwent preoperative lymphoscintigraphy for sentinel node mapping. Sentinel node detection rate with conventional planar imaging was similar to that of SPECT/CT (87.1 versus 91.8 %) in the whole cohort. However, SPECT/CT detected a higher number of sentinel nodes in more than one third of patients, affected by either cervical or endometrial carcinoma. The rate of non or insufficiently contributive procedures (lack of uptake or unilateral uptake) in endometrial carcinomas was 47 % with conventional planar imaging, and 30 % with SPECT/CT. Sensitivity of both procedures for the detection of metastatic nodes was 81.8 %, compared to 100 % for the intraoperative combined detection (gamma probe sonde and blue dye). The impact of SPECT/CT for the sentinel lymph node detection in cervical and endometrial carcinomas needs further evaluation. Nevertheless, SPECT/CT may provide additional information when conventional planar imaging detects only unilateral uptake, may improve identification of atypical localizations, and facilitate surgical approach.     

Apport de l’IRM dans l’imagerie pelvienne : aspect normal et pathologique

The pelvic MRI allows a better morphological analysis of the uterus (cervix and body) and ovaries compared to CT scan either before or after injection. MRI is the modality of choice for preoperative staging and follow-up of cervical and endometrial tumors. MRI assessed tumor response, detect recurrences. MRI also allows better characterization of ovaries lesions.     

La cognition dans le trouble obsessionnel compulsif : à l’intersection de la clinique et de la neuro-imagerie

The investigation of neural activity in OCD (Obsessive Compulsive Disorder) has allowed to link obsessive compulsive symptoms and cortico-striatal dysfunction. In the present article, we try to show the significance of cognition in an integrative physiopathologic model of OCD. Clinically, patients are unable to inhibit irrelevant thoughts or actions. In a cognitive way, decision making, planification or organisation are impaired. Those impairments are related to an executive deficit, which depends on frontal structures. Finally, we present a current study which tries to identify executive deficit functions related to cerebral dysfunction in patients presenting different OCD features (washing, checking, hoarding).     

Intérêt de l’imagerie hybride TEMP-TDM dans l’exploration des infections

Single-Photon Emission Computed Tomography-Computerized Tomography (SPECT-CT) is a new hybrid technique which offers new diagnostical capabilities in daily nuclear medicine practice. This technique not only allows to acquire fusioned anatomic and functional images in the same time, but also, it increases sensitivity and accuracy of SPECT thanks to attenuation and scattering corrections got from transmission data. Until now, SPECT-CT data have been mainly obtained in oncology and cardiology, but now, many authors use it in many scan studies and particularly for infectious diseases. In inflammatory bowel diseases, SPECT-CT seems to increase diagnostical performances and to modify management of many patients. In suspected vascular sepsis, SPECT-CT could increase sensitivity of white blood cell scintigraphy but also its specificity thanks to spatial resolution of CT. In osteoarticular sepsis, SPECT-CT has the advantage to distinguish osteomyelitis from soft tissue infection and to guide biopsies. Nevertheless, in the light of PET-CT works, SPECT-CT development will probably modify nuclear medicine practice and many studies have to be conducted to highlight consensual procedure guidelines.     

Impact de l’imagerie hybride TEMP/TDM dans le diagnostic et la prise en charge de l’ostéome ostéoïde

IntroductionThe osteoid osteoma is a major bone benign tumors in children. It is more common in boys. The femoral and tibial locations account for 50% of cases. Clinically, it is revealed by nocturnal pain relieved by aspirin. The pain may precede by several months the radiographic abnormality. The purpose of our work is to elucidate the contribution of SPECT/CT in addition to the planar bone scintigraphy in the diagnosis and treatment of osteoid osteoma about two cases.Case reportClinical case No. 1: a 10-year-old child who presented a limp nocturnal pain in the left hip evolving for 4 months. The radiograph of the pelvis showed bone condensation subtrochanteric left femur. SPECT/CT showed an image for an osteoid osteoma. Surgical resection of the home revealed in the histological study an osteoid osteoma of the left femoral neck. The evolution was marked by an immediate pain relief and full recovery of the left lower limb mobility. Clinical case No. 2: an 11-year-old child who had a limp nocturnal pain at the upper end of the left femur evolving for 2 months. The pain was paroxysmal, relieved by salicylates. The X-ray of the pelvis showed a metaphyseal image with peripheral condensation and thickening of the cortex. SPECT/CT showed an image for an osteoid osteoma. The intervention was a tumor excision resection. Histopathological examination revealed a small nidus consistent with an osteoid osteoma. The evolution was marked by an immediate pain relief and normalization of the mobility of the left lower limb.DiscussionThe SPECT/CT can increase the sensitivity and specificity of planar bone scintigraphy. It confirms the location of osteoid osteoma and defines its anatomical relationships in order to optimize surgical management.ConclusionThe SPECT/CT contributes significantly to the diagnosis of osteoid osteoma when radiological images are atypical or unusual clinical expression.     

Place de l’imagerie dans l’évaluation de l’efficacité des traitements dans le cancer du sein

This paper describes, from the current literature, the role of various imaging methods to assess the response to therapy in breast cancer. Two different clinical situations are considered: neoadjuvant chemotherapy of locally advanced breast cancer and the metastastic breast cancer. Significant clinical data are available for three criteria: the volume of the tumour, the uptake of fluorodeoxyglucose using PET and the perfusion of the tumor evaluated either by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) or by PET using ¹⁵O water. ¹⁸F FDG PET allows prediction of the response after one or two cycles of neoadjuvant chemotherapy. New approaches will offer opportunities to refine the role of imaging in monitoring the response to chemotherapy. PET using thymidine as biomarker is promising in assessing the tissular proliferation. Estrogen analogs could be used to predict hormonally responsive breast cancer. Many other approaches, although less developed, might offer new insights in the response to therapy of breast cancer like magnetic resonance spectroscopy or optical imaging of hemoglobin oxygenation. Imaging also offers potential of monitoring the down-regulation of specialized receptors of the cell membrane in response to treatment: the most studied receptor in preclinical model has been the human epidermal growth factor receptor type 2 (HER2). Integrin, a family of cell adhesion receptor, is also an important target for imaging. Apoptosis, multidrug resistance and hypoxia can also be studied using appropriate biomarkers. To allow reliable multicenter trials of new drugs, these different imaging approaches still require an improved standardization of image acquisition and processing.     

L’apport de la scintigraphie dans la pathologie de l’appareil locomoteur de l’enfant et de l’adolescent. Regards croisés du clinicien et du scintigraphiste

This paper summarizes and clarifies the clinician's reasoning in front of a lesion of the musculoskeletal system and his appeal to the examinations of imaging and to his choices. It proposes an analysis of the criteria of choice of bone scanning in this arsenal of exploration. It details the keys of the dialogue between the clinician and the nuclear physician: firstly, the clinician determines the elements of his request and its areas of doubt and uncertainty, and his diagnosis of probability and, secondly, the nuclear physician adapts the nature of the examination according to the problem posed.     

Le Gravettien et l’Épigravettien de l’Est de la Roumanie : une réévaluation

Opening towards the eastern steppe landmass, the Eastern Romania area covers 87,500 km², and shelters the biggest number of Gravettian and Epigravettian sites currently known. Archaeological researches in the area expanded in the 1950's, during the construction of dams on the Prut and Bistrița valleys. The efforts of the multidisciplinary teams involved and the subsequently published papers highlighted the archaeological potential of the region and, with some inevitable interruptions, investigations continued to this day. Although the time and resources spent were not modest, the outcomes regarding the Upper Palaeolithic cultural sequence often proved contradictory and somehow distant from the general European cultural dynamic. Thus, this reassessment tries to put the chronological, palaeoenvironmental, and empirical data in a more coherent framework. A synthesis of the available Gravettian and Epigravettian data east of the Carpathians reveals the following sequence: (1) an Aurignacian stage on the Prut Valley, paralleled by an indefinite Upper Palaeolithic stage, from sites on the Bistrița Valley, between 31 and 28 ka (uncal BP); (2) a quite early Gravettian presence, roughly between 27 and 25.5 ka, which includes backed laminar blanks, schematic decoration of one pendant, and the use of perforated shells as adornments; (3) a scant shouldered points stage, chronologically close to the European similar phases (25–23 ka), for which the feeble use of obsidian points toward contacts with Central European resources/populations; (4) a Gravettian/Epigravettian interface, between 21 and 19 ka, manifested within numerous archaeological layers, mainly through an increase in bladelets and organic artefacts production/use; (5) an Epigravettian stage, between 18 and 16 ka, largely defined through an upturn in raw material choices, backed implements production, and tool types; (6) one last, roughly 14 ka old Epigravettian stage, in which the technological choices recalled those of the previous one. Regional variability elements and radiocarbon chronology limitations considered, apparently, the Gravettian and the Epigravettian of Eastern Romania share quite a lot of traits with the corresponding Central and Eastern European technocomplexes.     

Application de l’imagerie moléculaire par fluorescence à la clinique

Fluorescence probes and imaging methods have been extensively developed in microscopy to visualize biological pathways, cell trafficking and intracellular interactions, which are the main targets of molecular imaging. The translation of these methods from microscopy to preclinical and clinical applications requires to image through large thickness of live biological tissues, and to ensure the non-toxicity of the probes. We hereafter list the main issues that must be addressed to translate fluorescence techniques to clinic, and we present the main envisioned solutions. As first realistic clinical application, we present work in progress on intraoperative fluorescence guided surgery.     

Indications de l’imagerie dans l’infertilité masculine (bourses,testicules)

Imaging modalities in the work up of male infertility are almost resumed to Ultrasound with Color Doppler which is quite performant if its indications are well-balanced:

-To look for abnormalities of the seminal tract.

-To evaluate clinical varicoceles (Testis, associated abnormalities).

-To screen the neoscrotal pouchs of ectopic operatively corrected Testis (occult tumor, epididymal abnormalities).