Publications (11)39.59 Total impact
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Article: Can we achieve a radionuclide radiation dose equal to or less than that of 99mTc-hydroxymethane diphosphonate bone scintigraphy with a low-dose 18F-sodium fluoride time-of-flight PET of diagnostic quality?
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ABSTRACT: PURPOSE: F-Sodium fluoride is a bone tracer with a high signal-to-noise ratio, but its dosimetry is higher than that of Tc-labeled phosphonates at the recommended activities. The study's purpose was to determine whether the reduction by half of F-sodium fluoride-injected activity, mimicked by a short-timed reconstruction image, simulating a total dose less than or equal to that of Tc-hydroxymethane diphosphonate scintigraphy, had an impact on the accuracy of PET semiquantitative measurements and image quality. METHODS: Whole-body time-of-flight F-sodium fluoride PET/computed tomography (CT) images were acquired prospectively from 40 adult patients for detection of bone metastases. F-Sodium fluoride was administered according to the European Association of Nuclear Medicine (EANM) and Society of Nuclear Medicine (SNM) practice guidelines. From the acquired 1 min/bed position list-mode data, 30-s reconstructions were extracted. Measurements of maximum standard uptake value were recorded with a region of interest applied to the same location on the 1-min and 30-s images, which were displayed side by side, and were analyzed using Bland-Altman plots. A masked reading was performed by two senior nuclear medicine physicians who counted the foci of visually increased uptake. RESULTS: Bland-Altman plots showed an excellent agreement between the maximum standard uptake value measurements of the 60- and 30-s images. The paired Wilcoxon test results between the corresponding 60- and 30-s images read by masked readers A and B were not significant (P=0.15 and 0.19, respectively). CONCLUSION: Reducing acquisition duration by half or injecting half of the activity recommended by the EANM and SNM practice guidelines can lead to F-sodium fluoride time-of-flight PET images of diagnostic quality, achieving a radiation dose less than or equal to that of Tc-labeled phosphonates.Nuclear Medicine Communications 03/2013; · 1.40 Impact Factor -
Article: (18)F-Fluorodihydroxyphenylalanine vs other radiopharmaceuticals for imaging neuroendocrine tumours according to their type.
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ABSTRACT: 6-Fluoro-((18)F)-L-3,4-dihydroxyphenylalanine (FDOPA) is an amino acid analogue for positron emission tomography (PET) imaging which has been registered since 2006 in several European Union (EU) countries and by several pharmaceutical firms. Neuroendocrine tumour (NET) imaging is part of its registered indications. NET functional imaging is a very competitive niche, competitors of FDOPA being two well-established radiopharmaceuticals for scintigraphy, (123)I-metaiodobenzylguanidine (MIBG) and (111)In-pentetreotide, and even more radiopharmaceuticals for PET, including fluorodeoxyglucose (FDG) and somatostatin analogues. Nevertheless, there is no universal single photon emission computed tomography (SPECT) or PET tracer for NET imaging, at least for the moment. FDOPA, as the other PET tracers, is superior in diagnostic performance in a limited number of precise NET types which are currently medullary thyroid cancer, catecholamine-producing tumours with a low aggressiveness and well-differentiated carcinoid tumours of the midgut, and in cases of congenital hyperinsulinism. This article reports on diagnostic performance and impact on management of FDOPA according to the NET type, emphasising the results of comparative studies with other radiopharmaceuticals. By pooling the results of the published studies with a defined standard of truth, patient-based sensitivity to detect recurrent medullary thyroid cancer was 70 % [95 % confidence interval (CI) 62.1-77.6] for FDOPA vs 44 % (95 % CI 35-53.4) for FDG; patient-based sensitivity to detect phaeochromocytoma/paraganglioma was 94 % (95 % CI 91.4-97.1) for FDOPA vs 69 % (95 % CI 60.2-77.1) for (123)I-MIBG; and patient-based sensitivity to detect midgut NET was 89 % (95 % CI 80.3-95.3) for FDOPA vs 80 % (95 % CI 69.2-88.4) for somatostatin receptor scintigraphy with a larger gap in lesion-based sensitivity (97 vs 49 %). Previously unpublished FDOPA results from our team are reported in some rare NET, such as small cell prostate cancer, or in emerging indications, such as metastatic NET of unknown primary (CUP-NET) or adrenocorticotropic hormone (ACTH) ectopic production. An evidence-based strategy in NET functional imaging is as yet affected by a low number of comparative studies. Then the suggested diagnostic trees, being a consequence of the analysis of present data, could be modified, for some indications, by a wider experience mainly involving face-to-face studies comparing FDOPA and (68)Ga-labelled peptides.European Journal of Nuclear Medicine 02/2013; · 4.53 Impact Factor -
Article: Added value of early 18F-FDOPA PET/CT acquisition time in medullary thyroid cancer.
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ABSTRACT: The aim of this study was to determine whether early acquisition of F-fluorodihydroxyphenylalanine (F-FDOPA) PET/CT could improve the detection of medullary thyroid cancer (MTC). We retrospectively compared early (median time: 15 min) and delayed (median time: 94 min) acquisitions, positive on at least one of the two phases, in 15 dual-phase F-FDOPA PET/CT examinations performed on 14 patients referred for initial staging (one examination), suspected recurrence (eight examinations) or restaging of MTC (six examinations). Among the 14 true-positive (TP) examinations, more lesions (51 vs. 43) or more intense uptake (mean SUVmax=4 vs. 2.4, P<0.05) was observed on early versus delayed phases, regardless of the anatomical site of disease (lymph node, liver or bone). The only false-positive case, a reactive lymph node, was visible only on the delayed acquisition. Early acquisition appeared to be more appropriate in the detection of MTC lesions compared with acquisition at 60 min or later.Nuclear Medicine Communications 04/2012; 33(7):775-9. · 1.40 Impact Factor -
Article: A pilot comparison of 18F-fluorodeoxyglucose and 18F-fluorocholine PET/CT to predict early recurrence of unifocal hepatocellular carcinoma after surgical resection.
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ABSTRACT: Presurgical identification of patients at high risk for early recurrence of hepatocellular carcinoma (HCC) after resection could warrant additional therapies. F-fluorodeoxyglucose (FDG) uptake by the tumour on preoperative PET can predict HCC recurrence after resection as effectively as poor differentiation or presence of microvascular invasion (MVI) on postsurgical histology. A better sensitivity for the detection of HCC nodules has been reported with F-fluorocholine (FCH), a PET tracer of lipid metabolism. This pilot study aimed to compare preoperative FDG and FCH PET/CT for predicting early recurrence of unifocal HCC, occurring within 6 months after surgical resection. FDG and FCH tumour uptakes were assessed on preoperative PET/CT by two masked readers. On FCH PET/CT, a photopenic lesion and a hot focus were considered as indicative of malignancy. During postoperative follow-up, recurrence was searched for by regularly performing CT and MRI. In 11 consecutive HCC patients, the detection rate was greater with FCH (80%) than with FDG (27%). After resection, the overall recurrence rate was 55%. Early recurrence occurred in four patients, who were the only ones with an FDG-positive and FCH-photopenic tumour, with a significant reduction in disease-free survival. On postsurgical histology, those four patients also presented with MVI and satellite nodules. Histological differentiation and capsule disruption appeared less accurate than PET/CT or MVI in predicting early recurrence. In unifocal HCC, the FCH photopenic pattern was associated with MVI and predicted early HCC recurrence after surgical resection as accurately as did an FDG uptake. Larger studies with FCH are warranted.Nuclear Medicine Communications 04/2012; 33(7):757-65. · 1.40 Impact Factor -
Article: Detection of hepatocellular carcinoma with PET/CT: a prospective comparison of 18F-fluorocholine and 18F-FDG in patients with cirrhosis or chronic liver disease.
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ABSTRACT: This prospective study aimed to compare the diagnostic performance of (18)F-fluorocholine and (18)F-FDG for detecting and staging hepatocellular carcinoma (HCC) in patients with chronic liver disease and suspected liver nodules. Whole-body PET/CT was performed in a random order at 10 min after injection of 4 MBq of (18)F-fluorocholine per kilogram and at 1 h after injection of 5 MBq of (18)F-FDG per kilogram. PET/CT results were read in a masked manner by 2 specialists, and diagnostic performance was assessed from the results of consensus masked reading. Those focal lesions appearing with increased or decreased activity, compared with background, on (18)F-fluorocholine PET/CT were considered positive for malignancy. The standard of truth was determined on a per-site basis using data from a histologic examination and a follow-up period of more than 6 mo; on a per-patient basis, the Barcelona criteria were also accepted as a proof of HCC in 5 patients. Eighty-one patients were recruited; standard of truth was determined in 59 cases. HCC was diagnosed in 34 patients. Therefore, sensitivity was 88% for (18)F-fluorocholine and 68% for (18)F-FDG (P = 0.07), and in 70 sites, sensitivity was 84% for (18)F-fluorocholine, significantly better than the 67% for (18)F-FDG (P = 0.01). Of the 11 patients with well-differentiated HCC, 6 had a positive result with (18)F-fluorocholine alone, whereas (18)F-FDG was never positive alone; corresponding site-based sensitivity was 94% for (18)F-fluorocholine and 59% for (18)F-FDG (P = 0.001). The detection rate of 18 sites corresponding to other malignancies was 78% for (18)F-fluorocholine and 89% for (18)F-FDG. In nonmalignant sites, (18)F-fluorocholine appeared less specific than (18)F-FDG (62% vs. 91% P < 0.01) because of uptake by focal nodular hyperplasia. (18)F-fluorocholine was significantly more sensitive than (18)F-FDG at detecting HCC, in particular in well-differentiated forms. In contrast, (18)F-FDG appeared somewhat more sensitive at detecting other malignancies and was negative in focal nodular hyperplasia. Thus (18)F-fluorocholine appears to be a useful PET/CT tracer for the detection and surveillance of HCC; however, performing PET/CT with both radiopharmaceuticals seems to be the best option.Journal of Nuclear Medicine 10/2010; 51(11):1699-706. · 6.38 Impact Factor -
Article: Impact of fluorodihydroxyphenylalanine-18F positron emission tomography on management of adult patients with documented or occult digestive endocrine tumors.
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ABSTRACT: Fluorodihydroxyphenylalanine-(18F) (FDOPA) positron emission tomography (PET) is a recent imaging modality used to localize endocrine tumors. This study was conducted to evaluate the impact of FDOPA-PET on the management of patients referred for carcinoid or noncarcinoid digestive tumors and the clinical relevance of the treatment decisions based on this examination. Between March 2002 and December 2006, 101 FDOPA-PET examinations were performed in 78 adult patients for follow-up of histologically documented carcinoid tumor of the ileum (23 patients) or noncarcinoid digestive tumor (26 patients) or to screen for occult digestive endocrine tumors (29 patients). More than one FDOPA-PET examination was performed in 12 patients. The impact of FDOPA PET was evaluated on a per-patient basis by means of a questionnaire completed by the referring physician, and the relevance of the treatment decision was assessed on the basis of follow-up data. The survey response rate was 91% (71 of 78). The overall impact rate of FDOPA-PET on patient management was 25% (18 of 71). The greatest impact was observed for carcinoid tumors (50%: 11 of 22) and was clinically relevant in every case, followed by occult endocrine tumors (16%: four of 25), and was clinically relevant in three of the four cases, and noncarcinoid tumors (13%: 3 of 22), clinically relevant in only one case. FDOPA-PET appears to be a major tool for the management of carcinoid tumors with excellent diagnostic performances and induced relevant changes in patient management. FDOPA-PET was less sensitive and less useful for the management of noncarcinoid tumors.The Journal of clinical endocrinology and metabolism 02/2009; 94(4):1295-301. · 6.50 Impact Factor -
Article: Early evaluation of the effects of chemotherapy with longitudinal FDG small-animal PET in human testicular cancer xenografts: early flare response does not reflect refractory disease.
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ABSTRACT: We aimed to evaluate the usefulness of FDG PET in the early prediction of the effects of chemotherapy on human testicular cancer xenografts. Nude rats bearing subcutaneous human embryonal carcinoma xenografts received either cisplatin (5 mg/kg) or saline serum. Small-animal PET studies were performed on days 0, 2, 4 and 7 and compared to immunochemistry studies, flow cytometry studies and hexokinase assays. Cisplatin treatment resulted in biphasic FDG uptake evolution: a peak was observed on day 2, followed by a marked decrease on day 7 despite an insignificant change in tumour volume. Similarly, a peak in cyclin A immunostaining was observed on days 2 and 4), followed by a significant decrease on day 7. Flow cytometry showed that the cyclin A peak was not related to increased cell proliferation but was due to a transient S and G(2)/M cell cycle arrest. A marked increase in cell apoptosis was observed from day 2 to day 7. GLUT-1 showed a significant decrease on day 7. Macrophagic infiltrate remained stable except for an increase observed on day 7. In control tumours, continuous growth was observed, all immunostaining markers remaining stable over time. Hexokinase activity was significantly lower on day 7 in treated tumours than in controls. FDG PET may be useful in the early evaluation of treatment in patients with testicular cancer. In our model, a very early increased [(18)F]-FDG uptake was related to a transient cell cycle arrest and early stage apoptosis but did not reveal refractory disease.European Journal of Nuclear Medicine 01/2009; 36(3):396-405. · 4.53 Impact Factor -
Article: Improvement of semi-quantitative small-animal PET data with recovery coefficients: a phantom and rat study.
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ABSTRACT: To evaluate the accuracy of semi-quantitative small-animal PET data, uncorrected for attenuation, and then of the same semi-quantitative data corrected by means of recovery coefficients (RCs) based on phantom studies. A phantom containing six fillable spheres (diameter range: 4.4-14 mm) was filled with an 18F-FDG solution (spheres/background activity=10.1, 5.1 and 2.5). RCs, defined as measured activity/expected activity, were calculated. Nude rats harbouring tumours (n=50) were imaged after injection of 18F-FDG and sacrificed. The standardized uptake value (SUV) in tumours was determined with small-animal PET and compared to ex-vivo counting (ex-vivo SUV). Small-animal PET SUVs were corrected with RCs based on the greatest tumour diameter. Tumour proliferation was assessed with cyclin A immunostaining and correlated to the SUV. RCs ranged from 0.33 for the smallest sphere to 0.72 for the largest. A sigmoidal correlation was found between RCs and sphere diameters (r(2)=0.99). Small-animal PET SUVs were well correlated with ex-vivo SUVs (y=0.48x-0.2; r(2)=0.71) and the use of RCs based on the greatest tumour diameter significantly improved regression (y=0.84x-0.81; r(2)=0.77), except for tumours with important necrosis. Similar results were obtained without sacrificing animals, by using PET images to estimate tumour dimensions. RC-based corrections improved correlation between small-animal PET SUVs and tumour proliferation (uncorrected data: Rho=0.79; corrected data: Rho=0.83). Recovery correction significantly improves both accuracy of small-animal PET semi-quantitative data in rat studies and their correlation with tumour proliferation, except for largely necrotic tumours.Nuclear Medicine Communications 11/2007; 28(10):813-22. · 1.40 Impact Factor -
Article: FDOPA PET has clinical utility in brain tumour imaging: a proposal for a revision of the recent EANM guidelines.
European journal of nuclear medicine and molecular imaging 08/2007; 34(7):1131-2; author reply 1133-4. · 4.99 Impact Factor -
Article: Safety of 18F-DOPA injection for PET of carcinoid tumor.
Journal of Nuclear Medicine 11/2006; 47(10):1732; author reply 1732. · 6.38 Impact Factor -
Article: [Basics of PET and PET/CT imaging: instrumentation and radiopharmaceuticals for clinical diagnosis].
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ABSTRACT: Positron emission tomography (PET), like scintigraphy, is a type of functional and molecular imaging. Image resolution is better than with scintigraphy, and tomographic slices are obtained, as with CT and MRI. Modern PET machines are coupled with CT (PET/CT) and yield fused images that combine metabolic and anatomic approaches. Fludeoxyglucose (FDG), a radiolabeled glucose analog, is the most widely used radiopharmaceutical for clinical PET, but several other molecules are proposed for routine use. Clinical trials will determine which are of clinical interest. FDG imaging necessarily involves PET but clinical PET is not only FDG imaging.La Presse Médicale 10/2006; 35(9 Pt 2):1331-7. · 0.67 Impact Factor
Top co-authors
Top Journals
Institutions
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2013
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Comenius University in Bratislava
- Department of Nuclear Medicine
Bratislava, Bratislavsky Kraj, Slovakia
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2009–2012
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Assistance Publique – Hôpitaux de Paris
Paris, Ile-de-France, France -
Université de Caen Basse-Normandie
Caen, Basse-Normandie, France
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2007
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Centre François Baclesse
Caen, Basse-Normandie, France
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