21 research outputs found
IntĂ©rĂȘt de la TEP au 18-FDG dans l'Ă©valuation de la rĂ©ponse Ă la radioimmunothĂ©rapie des patients porteurs de lymphomes malins non hodgkiniens traitĂ©s par Yttrium-90 Epratuzumab
Objectif : ApprĂ©cier l'intĂ©rĂȘt de la FDG-TEP dans l'Ă©valuation de la rĂ©ponse Ă la radioimmunothĂ©rapie de patients traitĂ©s par 90Y epratuzumab dans un protocole de phase I/II. MatĂ©riels et mĂ©thodes : Des scanners thoraco-abdomino-pelviens et des TEP ont Ă©tĂ© rĂ©alisĂ©s lors de l'Ă©valuation prĂ©-thĂ©rapeutique, Ă 6 semaines, 3, 6, 9 , 12 et 18 mois aprĂšs chaque cure de RIT. La rĂ©ponse tumorale Ă©tait Ă©valuĂ©e par la TDM selon les recommandations internationales et comparĂ©e Ă l'analyse qualitative et quantitative des images TEP classĂ©es en 3 types de rĂ©ponse: rĂ©ponse complĂšte (RC) ou incomplĂšte (RI), et progression (PM). RĂ©sultats : La rĂ©ponse thĂ©rapeutique Ă 13 cures de RIT a Ă©tĂ© Ă©valuĂ©e par 36 procĂ©dures d'examen (FDG-TEP et scanners). Les patients rĂ©pondeurs Ă la RIT pouvaient ĂȘtre identifiĂ©s par la FDG-TEP dĂšs 6 semaines aprĂšs le traitement. Les valeurs de sensibilitĂ©s de la FDG-TEP Ă©taient meilleures que celles du scanner pour le staging initial comme pour la dĂ©tection des rĂ©cidives (95 et 98% versus 54 et 36%). La FDG-TEP avait une meilleure valeur prĂ©dictive positive que le scanner pour l'Ă©valuation des masses rĂ©siduelles. Conclusion : Cette Ă©tude montre l'intĂ©rĂȘt de la FDG-TEP dans l'Ă©valuation de la rĂ©ponse Ă la RIT. Si ces donnĂ©es Ă©taient confirmĂ©es sur une population plus importante, la FDG-TEP pourrait ĂȘtre incluse dans le bilan standard d'Ă©valuation de la rĂ©ponse Ă la RIT, thĂ©rapeutique encore en cours d'optimisation.NANTES-BU MĂ©decine pharmacie (441092101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
Radioimmunothérapie du cancer médullaire de la thyroïde
Ce travail a Ă©valuĂ© la toxicitĂ© et l'efficacitĂ© de la radioimmunothĂ©rapie (RIT) en deux temps avec l'anticorps bispĂ©cifique murin anti-CEA/anti-DTPA F6-734 et le haptĂšne bivalent di-DTPA-131I (rĂ©actifs AES) chez des souris greffĂ©es avec un cancer mĂ©dullaire de la thyroĂŻde (CMT) et chez 26 patients porteurs de rĂ©cidives de CMT inclus dans une Ă©tude de phase I/II. Chez l'animal, la biodistribution des rĂ©actifs AES Ă©tait plus favorable que celle du mĂȘme anticorps anti-ACE directement marquĂ© et la RIT en deux temps aussi efficace et moins toxique que la RIT en un temps. Des injections rĂ©pĂ©tĂ©es de rĂ©actifs AES ou l'association avec le paclitaxel amĂ©liorait l'efficacitĂ© de la RIT sans altĂ©rer la tolĂ©rance, l'association ayant un effet synergique. Dans l'Ă©tude clinique, la toxicitĂ© hĂ©matologique a limitĂ© l'escalade de dose. La dose maximale tolĂ©rĂ©e Ă©tait de 48 mCi/m2. Les rĂ©sultats dosimĂ©triques Ă©taient favorables et quatre rĂ©ponses tumorales ont Ă©tĂ© observĂ©es.This study evaluated toxicity and efficacy of two-step radioimmunotherapy (RIT) using anti-CEA/anti- DTPA F6-734 murine bispecific antibody F6-734 and di-DTPA-131I bivalent hapten (AES reagents) in mice grafted with a medullary thyroid carcinoma (MTC) and in 26 patients with recurrences of MTC enrolled in a phase I/II trial. In animal, biodistribution was more favorable with AES reagents than with directly labeled fragment of the same anti-CEA antibody. Two-step RIT was at least as efficient as one-step RIT, and markedly less toxic. Repeated injection of AES reagents increased RIT efficacy without increasing toxicity. Addition of paclitaxel improved RIT efficacy with synergistic effect, without increasing toxicity. In the clinical trial, dose-limiting toxicity was hematological, and maximum tolerated dose 48 mCi/m2. Dosimetric results were favorable and four tumor responses were observed.NANTES-BU MĂ©decine pharmacie (441092101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF
Reconstruction 3D complÚte par modélisation Monte Carlo de la matrice systÚme (apport aux approches quantitatives à l'iode 131)
La correction des phĂ©nomĂšnes physiques dĂ©gradant l'information quantitative en imagerie SPECT fait l'objet de nombreux dĂ©veloppements. La rĂ©solution du problĂšme est rendu particuliĂšrement dĂ©licate pour des acquisitions Ă l'iode 131 compte tenu de la complexitĂ© du spectre d'Ă©mission et des nombreux biais quantitatifs qui en dĂ©coulent. L'objectif de ce travail de thĂšse a Ă©tĂ© de mettre en Ćuvre une mĂ©thode de reconstruction tridimensionnelle complĂšte par modĂ©lisation Monte Carlo de la matrice systĂšme (F3DMC) et de l'optimiser en vue de son utilisation dans un contexte clinique. Les premiers rĂ©sultats obtenus sur un fantĂŽme analytique ont nĂ©cessitĂ© l utilisation de l'infrastructure de calcul et de stockage massif EGEE et ont mis en Ă©vidence l'importance d'obtenir un projecteur statistiquement robuste. A n de pallier cette difficultĂ© nous avons utilisĂ© une technique d'accĂ©lĂ©ration des simulations fondĂ©e sur la tabulation de la fonction de rĂ©ponse angulaire du couple collimateur/dĂ©tecteur (ARF). Cette nouvelle mĂ©thode a Ă©tĂ© Ă©valuĂ©e et validĂ©e pour des acquisitions Ă l iode 131 et a montrĂ© que, Ă qualitĂ© de signal Ă©quivalente, nous pouvions atteindre un facteur d'accĂ©lĂ©ration proche de 100 dans un milieu hĂ©tĂ©rogĂšne rĂ©aliste par rapport Ă une simulation Monte Carlo standard. Cette mĂ©thodologie a Ă©tĂ© incorporĂ©e dans l'algorithme de construction du projecteur puis testĂ©e sur le fantĂŽme et sur des donnĂ©es rĂ©elles. Cela a permis d'atteindre une robustesse statistique du projecteur nettement supĂ©rieure Ă celle obtenue sans utilisation de la mĂ©thode ARF avec une amĂ©lioration signi cative des gures de mĂ©rite quantitatives.The accuracy of quantitative imaging in SPECT is degraded by physical e ects, namely photon attenuation, Compton scatter and spatially varying collimator response. This problem is particularly di cult to tackle when using iodine-131-based acquisition because of the complexity of the associated spectrum. The objective of this thesis was to implement a fully 3D reconstruction using precise Monte Carlo simulations for estimating the projector (F3DMC) and to optimize the latter in order to be used in a clinical context. The rst results were obtained using the EGEE grid infrastructure and suggest that a more robust projector is needed to improve the accuracy of the quantitative information. To deal with this conclusion, we used a novel method to speed up simulations based on the angular response function of the collimator/detector (ARF). Therefore, we assessed the ARF methodology in the context of iodine-131 simulations. We found that a global acceleration factor of 100 could be reached compared to a standard Monte Carlo simulations when a realistic heterogeneous medium was involved. The ARF method was implemented in our F3DMC algorithm and was assessed with an analytical phantom and real data extracted from a patient acquisition. The association of the F3DMC and ARF methodologies came with a clear improvement of the quantitative results.NANTES-BU MĂ©decine pharmacie (441092101) / SudocSudocFranceF
Theranostic Radiopharmaceuticals : at the Inflection Point
International audienceThere has been a surge of interest in the field of âtheranosticâ (therapeutic + diagnostic) radiopharmaceuticals,both clinically and commercially. The potential has arguably been evident for several decades but there have beensome hard-learned lessons and some astonishing failures that have contributed to a lack of traction for the nuclearmedicine industry. There is evidence that this has now changed and recent product development, clinicaloutcomes and commercial focus have given the field a much-needed boost. In this article we explore the issuesand opportunities that currently define the field. We take the position that we are at the point where such a cost-effectiveand clinically beneficial precision medicine strategy has reached an inflection point on its trajectorytoward success
ImmunoPET to help stratify patients for targeted therapies and to improve drug development
International audienceno abstrac
IntĂ©rĂȘt pronostique de la TEP au FDG dans le bilan d'Ă©valuation thĂ©rapeutique intermĂ©diaire du lymphome de Hodgkin
BREST-BU MĂ©decine-Odontologie (290192102) / SudocSudocFranceF
Quantitative evaluation of Therapeutic response by FDG-PETâCT in Metastatic Breast Cancer
International audiencePurpose: To assess the therapeutic response for metastatic breast cancer with 18 F-FDG position emission tomography (PET), this retrospective study aims to compare the performance of six different metabolic metrics with PERCIST, PERCIST with optimal thresholds, and an image-based parametric approach. Methods: Thirty-six metastatic breast cancer patients underwent 128 PET scans and 123 lesions were identified. In a per-lesion and per-patient analysis, the performance of six metrics: maximum standardized uptake value (SUVmax), SUVpeak, standardized added metabolic activity (SAM), SUVmean, metabolic volume (MV), total lesion glycolysis (TLG), and a parametric approach (SULTAN) were determined and compared to the gold standard (defined by clinical assessment and biological and conventional imaging according RECIST 1.1). The evaluation was performed using PERCIST thresholds (for per-patient analysis only) and optimal thresholds (determined by the Youden criterion from the receiver operating characteristic curves). results: In the per-lesion analysis, 210 pairs of lesion evolutions were studied. Using the optimal thresholds, SUVmax, SUVpeak, SUVmean, SAM, and TLG were significantly correlated with the gold standard. SUVmax, SUVpeak, and SUVmean reached the best sensitivity (91, 88, and 83%, respectively), specificity (93, 95, and 97%, respectively), and negative predictive value (NPV, 90, 88, and 83%, respectively). For the per-patient analysis, 79 pairs of PET were studied. The optimal thresholds compared to the PERCIST threshold did not improve performance for SUVmax, SUVpeak, and SUVmean. Only SUVmax, SUVpeak, SUVmean, and TLG were correlated with the gold standard. SULTAN also performed equally: 83% sensitivity, 88% specificity, and NPV 86%. conclusion: This study showed that SUVmax and SUVpeak were the best parameters for PET evaluation of metastatic breast cancer lesions. Parametric imaging is helpful in evaluating serial studies
Incidental findings suggestive of COVID-19 in asymptomatic cancer patients undergoing 18F-FDG PET/CT in a low prevalence region
International audiencePurpose To assess the rate and pattern of incidental interstitial lung abnormalities suggestive of COVID-19 on 18F-FDG PET/ CT in asymptomatic cancer patients during the period of active COVID-19 circulation between March and April 2020 in a geographic area of low prevalence of the virus. routine oncological indication were retrospectively analyzed. No patients had symptoms suggestive of COVID-19 at the time of the 18F-FDG PET/CT. Incidental interstitial pneumonias suggestive of COVID-19 were identified, and the 18F-FDG PET/CT patterns were described. We compared the incidence of these lesions in the pre-COVID and pandemic phases. Results We observed a 1.6% increase in interstitial lung abnormalities during the period of COVID-19 circulation. All had < 50% lung involvement. We describe a case series with typical and atypical interstitial pneumonias suggestive of COVID-19 as unilateral or bilateral with ground-glass opacity, consolidation, or crazy-paving patterns. Conclusion The relatively low increase in incidental findings suggestive of COVID-19 infection on 18F-FDG PET/CT in asymptomatic cancer patients was in accordance with the low COVID-19 transmission in our geographic region. Nevertheless, nuclear medicine physicians should familiarize themselves with typical and atypical 18F-FDG PET/CT patterns suggestive of COVID-19 pneumonia and initiate appropriate intervention where necessary
Prognostic value of FDGâPET/CT response for patient selection before chimeric antigen receptorâTâcells therapy in nonâHodgkin lymphoma
International audienceNo abstract availabl