Prognostic value of bone marrow tracer uptake pattern in baseline PET scans in hodgkin lymphoma: Results from an international collaborative study

PET/CT-ascertained bone marrow involvement (BMI) constitutes the single most important reason for upstaging by PET/CT in Hodgkin lymphoma (HL). However, BMI assessment in PET/CT can be challenging. This study analyzed the clinicopathologic correlations and prognostic meaning of Different patterns of bone marrow (BM)18F-FDG uptake in HL. Methods: One hundred eighty newly Diagnosed early unfavorable and advanced-stage HL patients, all scanned at baseline and after 2 adriamycin-bleomycinvinblastine-dacarbazine (ABVD) courses with18F-FDG PET, enrolled in 2 international stuDies aimed at assessing the role of interim PET scanning in HL, were retrospectively included. Patients were treated with ABVD 4-6 cycles and involved-field raDiation when needed, and no treatment adaptation on interim PET scanning was allowed. Two masked reviewers independently reported the scans. Results: Thirty-eight patients (21.1%) had focal lesions (fPET1), 10 of them with a single (unifocal) and 28 with multiple (multifocal) BM lesions. Fifty-three patients (29.4%) had pure strong (.liver) Diffuse uptake (dPET1) and 89 (48.4%) showed no or faint (#liver) BM uptake (nPET1). BM biopsy was positive in 6 of 38 patients (15.7%) for fPET1, in 1 of 53 (1.9%) for dPET1, and in 5 of 89 (5.6%) for nPET1. dPET1 was correlated with younger age, higher frequency of bulky Disease, lower hemoglobin levels, higher leukocyte counts, and similar Diffuse uptake in the spleen. Patients with pure dPET1 had a 3-y progression-free survival identical to patients without any18F-FDG uptake (82.9% and 82.2%, respectively, P 5 0.918). However, patients with fPET1 (either unifocal or multifocal) had a 3-y progressionfree survival significantly inferior to patients with dPET1 and nPET1 (66.7% and 82.5%, respectively, P 5 0.03). The k values for interobserver agreement were 0.84 for focal uptake and 0.78 for Diffuse uptake. Conclusion: We confirmed that18F-FDG PET scanning is a reliable tool for BMI assessment in HL, and BM biopsy is no longer needed for routine staging. Moreover, the interobserver agreement for BMI in this study proved excellent and only focal18F-FDG BM uptake should be considered as a harbinger of HL

Intérêt de l'injection de produit de contraste iodé en imagerie par tomographie par émission de positions au 18F-2-fluoro-2-désoxyglucase couplée à une tomodensitométrie dans les lymphomes

La TEP-FDG est devenu un outil indispensable dans l'évaluation des lymphomes. Le but de cette étude était d'évaluer l'impact de l'utilisation d'une TDM injectée de produit de contraste iodé pour corriger l'atténuation en TEP-FDG dans les lymphomes. Méthodes. Cinquante patients suivis pour des lymphomes ont été inclus avant et après chimiothérapie. Les images de TEP ont été corrigées successivement à l'aide d'une "I'DM non injectée (TEP-) puis d'une TDMM injectée dee produit de contraste (TEP+). La première partie de l'étude a porté sur la mesure des valeurs de SUVmax, et de SUVmoyen au niveau de 10 tissus sains puis au niveau de lésions de lymphome sur les images de TEP- et de TEP+. La deuxième partie de l'étude s'est intéressée à l'impact qualitatif de l'utilisation d'une TDM injectée de produit de contraste. Quatre observateurs isotopistes ont coté les images de TEP- et de 'TEP+ dans un ordre aléatoire 4 semaines après la première cotation. Trois observateurs radiologues ont coté les images d'abord de TDM puis les mêmes images en s'aidant des images TEP. Résultats. Les valeurs de SUVmax, ont augmenté de manière significative sur les images de TEP+ au niveau de l'aorte (+14%), le foie (+10%), la rate (+10%) et la veine cave inférieure (+12%). Les valeurs de SUVmoyen en ont augmenté de manière significative sur les images de TEP+ au niveau de l'aorte (+15%), le rein (+13%), le foie (+l 1%), la rate (10%) et la veine cave inférieure (+12%). Les valeurs de SUVmax ont augmenté de manière significative après chimiothérapie au niveau de la vertèbre D12 (+12%). Les valeurs de SUVmoyen ont augmenté de manière significative après chimiothérapie au niveau de la vertèbre D12 (+13%) et au niveau du foie (+12%). Les valeurs de SUVmax et de SUVmoyen ont augmenté de manière significative sur les images de TEP+ au niveau des lésions (+4%) uniquement avant chimiothérapie. La concordance globale était de 99% quand les images de TEP- et de TEP+ furent comparées, avant (K=0,96) et après chimiothérapie (K=0,91). Neuf (5%) lésions étaient discordantes avant chimiothérapie (4 d'après la TEP+) et 8 (15%) lésions après chimiothérapie (5 d'après la TEP+). La concordance globale, lorsque les images de TDM furent comparées à celles lues conjointement à celles de TEP+, était de 97% (K=0,91) avant chimiothérapie et de 95% (x=0,76) après chimiothérapie. Vingt et une lésions (12%) étaient discordantes avant chimiothérapie (16 d'après la TDM seule) et 30 lésions (35%) après chimiothérapie (toutes d'après la TDM seule). Conclusion. Nous avons montré dans cette étude que les images de TEP ne différaient pas du point de vue quantitatif ou qualitatif, lorsqu'une TDM injectée de produit de contraste est utilisée pour corriger l'atténuation. Il existait quelques discordances lorsque les radiologues s'aidaient de la TEP pour interpréter la TDM, en particulier après chimiothérapie. Il est donc possible de réaliser un seul examen d'imagerie dans l'évaluation du lymphome, une TEP/TDM injectée de produit de contraste.ROUEN-BU Médecine-Pharmacie (765402102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Evaluation of exercise-induced myocardial stunning by means of immediate post exercise Tc-99m sestamibi gated SPECT

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Does chemotherapy influence the quantification of SUV when contrast-enhanced CT is used in PET/CT in lymphoma?

International audiencePURPOSE: In patients with lymphoma, we investigated the impact of contrast-enhanced CT on PET attenuation correction in lesions and normal tissues, particularly when PET/CT was performed after chemotherapy. METHODS: Fifty patients (51+/-18 years) with Hodgkin's disease (n=17) or non-Hodgkin lymphomas (n=33) were studied before and after chemotherapy. PET/CT scans were performed 60 min after injection of FDG. Iopamiron 300 (iopamidol, 1.5 cc/kg) was injected immediately afterwards, followed 50 s later by a second craniocaudal CT (CT+). PET images were successively reconstructed using the unenhanced CT (PET-) and the CT+ (PET+) for attenuation correction, using iterative reconstruction (4 iterations, 8 subsets, 5 mm post-filtering). HU(mean), SUV(max) and SUV(mean) were measured before and after chemotherapy in ten non-tumoural ROIs [aorta, femur, kidney, lung, iliopsoas muscle, occipital cortex, T12 vertebra, liver, spleen and inferior vena cava (IVC)] and in tumoural lymphadenopathies or malignant tissues (n=397 and 51 VOIs respectively before and after chemotherapy) using a 3D-thresholding method (identical threshold for PET- and PET+). ROIs were defined on the PET- and automatically applied on the unenhanced CT (CT-), the CT+ and the PET+. RESULTS: In the non-tumoural tissues, HU(mean) increased significantly in the CT+ compared with the CT- in the vessels and the highly vascularised organs, and slight increases were observed in the occipital cortex (+11%), the iliopsoas muscle (+6%) and the femur (+3%). SUV(max) increased significantly in the PET+ compared with the PET- in the aorta (+14%), the liver (+10%), the spleen (+10%) and the IVC (+12%). SUV(mean) increased significantly in the PET+ compared with the PET- in the aorta (+15%), the kidney (+13%), the liver (+11%), the spleen (10%) and the IVC (+12%). In the lesions, HU(mean) was not significantly different before and after chemotherapy, whatever the normal region considered. SUV(max) increased significantly after treatment in the T12 vertebra (+12%). SUV(mean) increased significantly after treatment in the T12 vertebra (+13%) and in the liver (+12%). HU(mean) increased significantly in the CT+ compared with the CT- in the lesions (+55%) before chemotherapy. SUV(max) and SUV(mean) increased significantly in the PET+ compared with the PET- in the lesions (+4%) only before chemotherapy. No significant difference was seen in measurements (HU(mean), SUV(max) and SUV(mean)) after chemotherapy. CONCLUSION: Our study demonstrates that use of enhanced CT for attenuation correction has a negligible effect on quantification at staging and after chemotherapy. A "single-shot" enhanced PET/CT may thus be performed in the evaluation of patients with lymphoma at staging, during treatment and at follow-up

Influence of PET/CT on radiologists and contrast-enhanced CT on nuclear medicine physicians in patients with lymphoma.

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