Valeur prédictive de la scintigraphie au mag3 captopril sur l'évolution de la fonction rénale

ROUEN-BU Médecine-Pharmacie (765402102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Évaluation précoce de la réponse à la radiothérapie par la tomographie par émission de positons au 2-fuoro-deoxy-glucose dans les cancers broncho pulmonaires non à petites cellules (bilan d'une étude prospective)

Objectifs: Ce travail s'inscrit dans un bilan intermédiaire d'une étude prospective analysant la valeur prédictive de la tomographie par émission de positons au FDG au cours de radiothérapie ou de radiochimiothérapie chez des patients porteurs de cancer bronchique non à petites cellules (CBNPC) localement évolués. Patients et Méthodes: Des patients suivis pour des CBNPC de stade III candidats à un traitement radical par radiothérapie ont été inclus. Pour chaque patient 4 TEP ont été réalisées, la première avant le début du traitement, la seconde en cours de radiothérapie à 42 Grays, les 2 suivantes à 3 et 12 mois après la fin de l'irradiation. Le SUVmax de la lésion primitive et des ganglions suspects a été mesuré. Ces valeurs ont été comparées à l'évolution clinique des patients sur un an. Résultats: Sur 43 patients inclus, les résultats de 27 patients ont pu être analysés. Avant la radiothérapie, aucune différence significative n'a été mise en évidence entre les valeurs de SUVmax et l'évolution clinique des patients. A 42 Gy,la médiane des SUVmax au niveau des lésions primitives des patients n'ayant pas récidivé était significativement inférieure à celle des patients ayant rechuté (1,47 vs 2,67; p=0,02). En cours de radiothérapie, la médiane des SUVmax ganglionnaires des patients survivants à 1 an était significativement plus faible que celle des patients décédés(1,01 vs 1,69 ; p=0,03). Conclusion: Pour cette analyse intermédiaire, les valeurs de SUVmax au niveau des lésions primitives ou ganglionnaires, sur la TEP en cours de radiothérapie, sembleraient être plus faible chez les patients présentant une évolution favorable. Ces résultats méritent d'être confirmés avec un effectif plus important dans la poursuite de cette étude.ROUEN-BU Médecine-Pharmacie (765402102) / SudocSudocFranceF

Follow-up of muscular sarcoidosis using fluorodeoxyglucoce positron emission tomography

International audienc

Patient-specific computational model and dosimetry calculations for a patient pregnant with twins undergoing a PET/CT examination

Purpose: The radiation dose delivered to pregnant patients during radiological imaging procedures raises health concerns because the developing embryo and fetus are considered to be highly radiosensitive. To appropriately weigh the diagnostic benefits against the radiation risks, the radiologist needs reasonably accurate and detailed estimates of the fetal dose. Expanding our previously developed series of computational phantoms for pregnant women, we here describe a personalized model for twin pregnancy, based on an actual clinical scan.Methods:The model is based on a standardized hybrid pregnant female and fetus phantom and on a clinical case of a patient who underwent an18F-fluoro-deoxyglucose (18F-FDG) positron emission tomography (PET) / computed tomography (CT) scan while expecting twins at 25-weeks' gestation. This model enabled us to produce a realistic physical representation of the pregnant patient and to estimate the maternal and fetal organ doses from the18F-FDG and CT components. The N-Particle eXtended (MCNPX) general purpose Monte Carlo code was used for radiation transport simulation.Results:The fetal18F-FDG doses for the two fetuses were 3.78 and 3.99 mGy, whereas the CT doses were 0.76 and 0.70 mGy, respectively. Therefore, the relative contribution of18F-FDG and CT to the total dose to the fetuses was about 84% and 16%, respectively. Meanwhile, for18F-FDG, the calculated personalized absorbed dose is about 40% - 50% higher than the values reported by other dosimetry computer software tools.Conclusion:Our approach for constructing personalized computational models allows the estimation of patient-specific radiation dose, even in cases with unusual anatomical features, such as a twin pregnancy. Our results also show that, even in twins, the fetal organ doses from both18F-FDG and CT present a certain variability linked to the anatomic characteristics. The CT fetal dose is smaller than the18F-FDG PET dose

Myocardial perfusion gated single-photon emission computed tomography in patients with left bundle branch block: comparison between the end-diastolic images and the ungated images.

International audienceOBJECTIVES: Septal perfusion abnormalities are frequently observed in patients with left bundle branch block (LBBB). The aim of this study was to compare myocardial perfusion imaging obtained from ungated and diastolic thallium gated single-photon emission computed tomography (SPECT) images in patients with LBBB. METHODS: Stress/rest SPECT was performed in 70 patients with LBBB [38 with coronary artery disease (CAD) (G1), 32 without (G2)] and 19 control participants (G3). Diastolic images were obtained as the sum of four diastolic bins. Perfusion was assessed by summed stress, rest, and difference scores for both diastolic and ungated images. RESULTS: In G1, there was no difference between diastolic and ungated perfusion scores. In G2, summed stress score and summed rest score were increased in diastolic versus ungated imaging, and perfusion defect extent was increased on diastolic versus ungated images at stress (diastole: 6.2 +/- 9.9% vs. ungated: 5.1 +/- 9.70/%, P = 0.01) and rest (diastole: 4.3 +/- 9.3% vs. ungated: 2.8 +/- 9.50%, P = 0.0014), with an increased extent of reversible defect (diastole: 3.4 4.7% vs. ungated: 2.3 3.7%, P = 0.01). In G2, diastolic images failed to correct septal perfusion abnormalities. The number of normal SPECT did not increase with diastolic versus ungated imaging (24 and 180% in G1, 66 and 53% in G2, respectively). Otherwise, a significant association between left ventricular dysfunction and CAD was found, stress ejection fraction being decreased in 20 patients (53%) in G1 and seven patients (22%) in G2 (CHI2 = 6.93, P < 0.01). CONCLUSION: In patients with LBBB, diastolic imaging did not provide additional information to ungated perfusion imaging, but left ventricular dysfunction was associated with CAD

Tc-99m-HMPAO-Labeled Leukocyte SPECT/CT in Pediatrics: Detecting Candida albicans Tricuspid Endocarditis

International audienc

Thyroid Incidentaloma on 18F-fluorocholine PET/CT and 68Ga-PSMA PET/CT Revealing a Medullary Thyroid Carcinoma

International audienceA 66-year-old man with prostate cancer underwent F-fluorocholine PET/CT and thereafter Ga-labeled prostate-specific membrane antigen PET/CT to explore a rising prostate-specific antigen level. Both PET/CT studies showed a thyroid incidentaloma of the right lobe. Neck ultrasound confirmed the presence of a 16-mm right thyroid nodule. The serum calcitonin level was moderately increased at 25 ng/mL (<10). Cytology was non-diagnostic (Bethesda I). A right lobectomy was performed and pathology revealed a 15-mm medullary thyroid cancer. Two months after surgery, the calcitonin level returned to normal at 3.3 ng/mL

Segmentation des images TEP au 18F-FDG : principe et revue de la littérature

National audienc