Yolande Petegnief

Assistance Publique – Hôpitaux de Paris, Lutetia Parisorum, Île-de-France, France

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Publications (24)48.78 Total impact

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    ABSTRACT: The purpose of this study was to assess the prognostic value of early (18)F-FDG PET using standardized uptake value (SUV) compared with visual analysis in patients with diffuse large B-cell lymphoma (DLBCL). Ninety-two patients with newly diagnosed DLBCL underwent (18)F-FDG PET prospectively before and after 2 cycles of chemotherapy (at midtherapy). Maximum SUV (SUVmax) and mean SUV (SUVmean) normalized to body weight and body surface area, as well as tumor-to-normal ratios, were computed on the most intense uptake areas. The SUVs, tumor-to-normal ratios, and their changes over time were compared with visual analysis for predicting event-free survival (EFS) and overall survival, using receiver-operating-characteristic (ROC) analysis. Survival curves were estimated with Kaplan-Meier analysis and compared using the log-rank test. With visual analysis, the accuracy of early PET to predict EFS was 65.2%. The 2-y estimate for EFS was 51% (95% confidence interval [CI], 34%-68%) in the PET-positive group compared with 79% (95% CI, 68%-90%) in the PET-negative group (P = 0.009). An optimal cutoff value of 65.7% SUVmax reduction from baseline to midtherapy obtained from ROC analysis yielded an accuracy of 76.1% to predict EFS. The 2-y estimate for EFS was 21% (95% CI, 0%-42%) in patients with SUVmax reduction <or= 65.7% compared with 79% (95% CI, 69%-88%) in those with reduction > 65.7% (P < 0.0001). Fourteen patients considered as positive on visual analysis could have been reclassified as good responders. SUV-based assessment of therapeutic response during first-line chemotherapy improves the prognostic value of early (18)F-FDG PET compared with visual analysis in DLBCL.
    Journal of Nuclear Medicine 10/2007; 48(10):1626-32. · 5.77 Impact Factor
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    ABSTRACT: [F-18]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is a non-invasive imaging technique which has recently been validated for the assessment of therapy response in patients with aggressive non-Hodgkin's lymphoma. Our objective was to determine its value for the evaluation of immunotherapy efficacy in immunocompetent Balb/c mice injected with the A20 syngeneic B lymphoma cell line. The high level of in vitro FDG uptake by A20 cells validated the model for further imaging studies. When injected intravenously, the tumour developed as nodular lesions mostly in liver and spleen, thus mimicking the natural course of an aggressive human lymphoma. FDG-PET provided three-dimensional images of tumour extension including non-palpable lesions, in good correlation with ex vivo macroscopic examination. When mice were pre-immunized with an A20 cell lysate in adjuvant before tumour challenge, their significantly longer survival, compared to control mice, were associated with a lower incidence of lymphoma visualized by PET at different time points. Estimation of tumour growth and metabolism using the calculated tumour volumes and maximum standardized uptake values, respectively, also demonstrated delayed lymphoma development and lower activity in the vaccinated mice. Thus, FDG-PET is a sensitive tool relevant for early detection and follow-up of internal tumours, allowing discrimination between treated and non-treated small animal cohorts without invasive intervention.
    Cancer Immunology and Immunotherapy 09/2007; 56(8):1163-71. · 3.64 Impact Factor
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    C Merheb, Y Petegnief, J N Talbot
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    ABSTRACT: Positron emission tomography (PET) systems dedicated to animal imaging are now widely used for biological studies. The scanner performance strongly depends on the design and the characteristics of the system. Many parameters must be optimized like the dimensions and type of crystals, geometry and field-of-view (FOV), sampling, electronics, lightguide, shielding, etc. Monte Carlo modelling is a powerful tool to study the effect of each of these parameters on the basis of realistic simulated data. Performance assessment in terms of spatial resolution, count rates, scatter fraction and sensitivity is an important prerequisite before the model can be used instead of real data for a reliable description of the system response function or for optimization of reconstruction algorithms. The aim of this study is to model the performance of the Philips Mosaic animal PET system using a comprehensive PET simulation code in order to understand and describe the origin of important factors that influence image quality. We use GATE, a Monte Carlo simulation toolkit for a realistic description of the ring PET model, the detectors, shielding, cap, electronic processing and dead times. We incorporate new features to adjust signal processing to the Anger logic underlying the Mosaic system. Special attention was paid to dead time and energy spectra descriptions. Sorting of simulated events in a list mode format similar to the system outputs was developed to compare experimental and simulated sensitivity and scatter fractions for different energy thresholds using various models of phantoms describing rat and mouse geometries. Count rates were compared for both cylindrical homogeneous phantoms. Simulated spatial resolution was fitted to experimental data for (18)F point sources at different locations within the FOV with an analytical blurring function for electronic processing effects. Simulated and measured sensitivities differed by less than 3%, while scatter fractions agreed within 9%. For a 410-665 keV energy window, the measured sensitivity for a centred point source was 1.53% and mouse and rat scatter fractions were respectively 12.0% and 18.3%. The scattered photons produced outside the rat and mouse phantoms contributed to 24% and 36% of total simulated scattered coincidences. Simulated and measured single and prompt count rates agreed well for activities up to the electronic saturation at 110 MBq for the mouse and rat phantoms. Volumetric spatial resolution was 17.6 microL at the centre of the FOV with differences less than 6% between experimental and simulated spatial resolution values. The comprehensive evaluation of the Monte Carlo modelling of the Mosaic system demonstrates that the GATE package is adequately versatile and appropriate to accurately describe the response of an Anger logic based animal PET system.
    Physics in Medicine and Biology 03/2007; 52(3):563-76. · 2.70 Impact Factor
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    ABSTRACT: Fully 3D Monte-Carlo (F3DMC) reconstruction consists in calculating a fully 3D object-specific system matrix using Monte-Carlo simulations and inverting it using an iterative approach. To reduce the large amount of disk space required by this approach, we derived a targeted F3DMC approach (TF3DMC) in which the volume to be reconstructed is irregularly sampled, so that pre-identified functional regions of interest are reconstructed using fine sampling while regions with non-specific activity or without any particular interest are coarsely sampled. This method was assessed using simulated and real SPECT data of a phantom filled with Tc99m. The GATE Monte-Carlo simulator was considered to simulate the phantom data and to calculate the system matrices needed for the reconstruction of the simulated and of the real SPECT data. Activity ratios measured in TF3DMC images were compared with those measured on F3DMC and OSEM images corrected for scatter, attenuation and detector response function. TF3DLMC yielded errors less than 10% in activity ratio estimates in hot regions, while errors with quantitative OSEM were between -21% and -3%. The space needed to store the system matrix was divided by a factor from 3.5 to 9.4 compared to F3DMC, for similar or even better accuracy in activity ratio estimates. These results suggest that TF3DMC can be made practical and outperforms F3DMC and OSEM in terms of quantitative accuracy.
    Nuclear Science Symposium Conference Record, 2006. IEEE; 12/2006
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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. · 0.87 Impact Factor
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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 09/2006; 35(9):1331-1337. · 0.87 Impact Factor
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    ABSTRACT: Monte Carlo modelling is widely used in nuclear medicine for system optimization and for image processing in order to obtain system data that cannot be measured experimentally. Any simulation model should be validated, especially in terms of spatial resolution, count rates, scatter fraction and sensitivity in the case of positron emission tomography (PET) systems. The aim of this study was to compare the performance of a Mosaic animal PET system model to the real system by using raw data in a list-mode format, in order to preserve all the precision and accuracy of the acquired data. GATE package was used to design a realistic model of the Mosaic system. Detectors, shielding, cap, air medium, phantoms, sources and electronic processing were simulated in GATE. Sensitivity obtained from experimental and simulated data were compared using the list-mode data for different energy windows. Measurements of count rates were performed for uniform cylindrical phantoms for both mouse and rat. Output data were recorded with the same spatial sampling as the experimental data. Point spread functions at different locations in the field of view were analysed in raw and reconstructed formats. Simulated and measured sensitivity differed by less than 5%. Simulated and measured single and prompt count rates agreed within 6% for activities up to 100 MBq for the two phantoms. A semi-empirical approach was used to simulate energy efficiency and losses of resolution after crystals interactions (detector blurring). Spatial resolution, assessed on simulated sinograms and on reconstructed data, agreed with real data. Comprehensive evaluation of the Monte Carlo modelling of a microPET system was performed using list-mode data and showed that the GATE model was appropriate to accurately reproduce the response of the system.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/2006; 569(2):220-224. · 1.14 Impact Factor
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    ABSTRACT: Purpose: To report a retrospective study concerning the impact of fused {sup 18}F-fluoro-deoxy-D-glucose (FDG)-hybrid positron emission tomography (PET) and CT images on three-dimensional conformal radiotherapy planning for patients with non-small-cell lung cancer. Methods and Materials: A total of 101 patients consecutively treated for Stage I-III non-small-cell lung cancer were studied. Each patient underwent CT and FDG-hybrid PET for simulation treatment in the same treatment position. Images were coregistered using five fiducial markers. Target volume delineation was initially performed on the CT images, and the corresponding FDG-PET data were subsequently used as an overlay to the CT data to define the target volume. Results: {sup 18}F-fluoro-deoxy-D-glucose-PET identified previously undetected distant metastatic disease in 8 patients, making them ineligible for curative conformal radiotherapy (1 patient presented with some positive uptake corresponding to concomitant pulmonary tuberculosis). Another patient was ineligible for curative treatment because the fused PET-CT images demonstrated excessively extensive intrathoracic disease. The gross tumor volume (GTV) was decreased by CT-PET image fusion in 21 patients (23%) and was increased in 24 patients (26%). The GTV reduction was {>=}25% in 7 patients because CT-PET image fusion reduced the pulmonary GTV in 6 patients (3 patients with atelectasis) and the mediastinal nodal GTV in 1 patient. The GTV increase was {>=}25% in 14 patients owing to an increase in the pulmonary GTV in 11 patients (4 patients with atelectasis) and detection of occult mediastinal lymph node involvement in 3 patients. Of 81 patients receiving a total dose of {>=}60 Gy at the International Commission on Radiation Units and Measurements point, after CT-PET image fusion, the percentage of total lung volume receiving >20 Gy increased in 15 cases and decreased in 22. The percentage of total heart volume receiving >36 Gy increased in 8 patients and decreased in 14. The spinal cord volume receiving at least 45 Gy (2 patients) decreased. Multivariate analysis showed that tumor with atelectasis was the single independent factor that resulted in a significant effect on the modification of the size of the GTV by FDG-PET: tumor with atelectasis (with vs. without atelectasis, p = 0.0001). Conclusion: The results of our study have confirmed that integrated hybrid PET/CT in the treatment position and coregistered images have an impact on treatment planning and management of non-small-cell lung cancer. However, FDG images using dedicated PET scanners and respiration-gated acquisition protocols could improve the PET-CT image coregistration. Furthermore, the impact on treatment outcome remains to be demonstrated.
    International Journal of Radiation OncologyBiologyPhysics 12/2005; 63(5). · 4.52 Impact Factor
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    ABSTRACT: To report a retrospective study concerning the impact of fused 18F-fluoro-deoxy-D-glucose (FDG)-hybrid positron emission tomography (PET) and CT images on three-dimensional conformal radiotherapy planning for patients with non-small-cell lung cancer. A total of 101 patients consecutively treated for Stage I-III non-small-cell lung cancer were studied. Each patient underwent CT and FDG-hybrid PET for simulation treatment in the same treatment position. Images were coregistered using five fiducial markers. Target volume delineation was initially performed on the CT images, and the corresponding FDG-PET data were subsequently used as an overlay to the CT data to define the target volume. 18F-fluoro-deoxy-D-glucose-PET identified previously undetected distant metastatic disease in 8 patients, making them ineligible for curative conformal radiotherapy (1 patient presented with some positive uptake corresponding to concomitant pulmonary tuberculosis). Another patient was ineligible for curative treatment because the fused PET-CT images demonstrated excessively extensive intrathoracic disease. The gross tumor volume (GTV) was decreased by CT-PET image fusion in 21 patients (23%) and was increased in 24 patients (26%). The GTV reduction was > or = 25% in 7 patients because CT-PET image fusion reduced the pulmonary GTV in 6 patients (3 patients with atelectasis) and the mediastinal nodal GTV in 1 patient. The GTV increase was > or = 25% in 14 patients owing to an increase in the pulmonary GTV in 11 patients (4 patients with atelectasis) and detection of occult mediastinal lymph node involvement in 3 patients. Of 81 patients receiving a total dose of > or = 60 Gy at the International Commission on Radiation Units and Measurements point, after CT-PET image fusion, the percentage of total lung volume receiving >20 Gy increased in 15 cases and decreased in 22. The percentage of total heart volume receiving >36 Gy increased in 8 patients and decreased in 14. The spinal cord volume receiving at least 45 Gy (2 patients) decreased. Multivariate analysis showed that tumor with atelectasis was the single independent factor that resulted in a significant effect on the modification of the size of the GTV by FDG-PET: tumor with atelectasis (with vs. without atelectasis, p = 0.0001). The results of our study have confirmed that integrated hybrid PET/CT in the treatment position and coregistered images have an impact on treatment planning and management of non-small-cell lung cancer. However, FDG images using dedicated PET scanners and respiration-gated acquisition protocols could improve the PET-CT image coregistration. Furthermore, the impact on treatment outcome remains to be demonstrated.
    International Journal of Radiation OncologyBiologyPhysics 12/2005; 63(5):1432-41. · 4.52 Impact Factor
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    ABSTRACT: To study the impact of fused (18)F-fluoro-deoxy-D-glucose (FDG)-hybrid positron emission tomography (PET) and computed tomography (CT) images on conformal radiotherapy planning for esophageal carcinoma patients. Thirty-four esophageal carcinoma patients were referred for concomitant radiotherapy and chemotherapy with radical intent. Each patient underwent CT and FDG-hybrid PET for simulation treatment in the same treatment position. PET images were coregistered using five fiducial markers. Target delineation was initially performed on CT images, and the corresponding PET data were subsequently used as an overlay to CT data to define the target volume. (18)F-fluorodeoxy-D-glucose-PET identified previously undetected distant metastatic disease in 2 patients, making them ineligible for curative conformal radiotherapy. The gross tumor volume (GTV) was decreased by CT and FDG image fusion in 12 patients (35%) and increased in 7 patients (21%). The GTV reduction was > or =25% in 4 patients owing to a reduction in the length of the esophageal tumor. The GTV increase was > or =25% with FDG-PET in 2 patients owing to the detection of occult mediastinal lymph node involvement in 1 patient and an increased length of the esophageal tumor in 1 patient. Modifications of the GTV affected the planning treatment volume in 18 patients. Modifications of the delineation of the GTV and displacement of the isocenter of the planning treatment volume by FDG-PET also affected the percentage of total lung volume receiving >20 Gy in 25 patients (74%), with a dose reduction in 12 patients and dose increase in 13. In our study, CT and FDG-PET image fusion appeared to have an impact on treatment planning and management of esophageal carcinoma. The affect on treatment outcome remains to be demonstrated.
    International Journal of Radiation OncologyBiologyPhysics 11/2005; 63(2):340-5. · 4.52 Impact Factor
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Journla of Immunotherapy 10/2005; 28(6):654. · 3.46 Impact Factor
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    ABSTRACT: To report a retrospective study concerning the impact of fused 18F-fluorodeoxy-D-glucose (FDG)-hybrid positron emission tomography (PET) and computed tomography (CT) images on three-dimensional conformal radiation therapy (3D-CRT) planning for patients with non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: One hundred and one patients consecutively treated for stages I-III NSCLC were studied. Each patient underwent CT and FDG-hybrid PET for simulation treatment in the same radiation treatment position. Images were coregistered using five fiducial markers. Target volume delineation was initially performed on the CT images and the corresponding FDG-PET data were subsequently used as an overlay to the CT data to define target volume. RESULTS: FDG-PET identified previously undetected distant metastatic disease in 8 patients making them ineligible for curative CRT (one patient presented some positive uptakes corresponding to concomitant pulmonary tuberculosis). Another patient was ineligible for curative treatment because fused CT/PET images demonstrated excessively extensive intrathoracic disease. The gross tumor volume (GTV) was decreased by CT/PET image fusion in 21 patients (23%) and was increased in 24 patients (26%). The GTV reduction was > or = 25% in 7 patients because CT/PET image fusion reduced pulmonary GTV in 6 patients (3 patients with atelectasis) and mediastinal nodal GTV in 1 patient. The GTV increase was > or = 25% in 14 patients due to an increase of the pulmonary GTV in 11 patients (4 patients with atelectasis) and detection of occult mediastinal lymph node involvement in 3 patients. Among 81 patients receiving a total dose > or = 60 Gy at ICRU point, after CT/PET image fusion, the percentage of total lung volume receiving more than 20 Gy (VL20) increased in 15 cases and decreased in 22 cases. The percentage of total heart volume receiving more than 36 Gy increased in 8 patients and decreased in 14 patients. The spinal cord volume receiving at least 45 Gy (2 patients) decreased. After multivariate analysis, one single independent factor made significant effect of FDG/PET on the modification of the size of the GTV: tumor with atelectasis (P = 0.0001). Conclusion. - Our study confirms that integrated hybrid PET/CT in the treatment position and coregistered images have an impact on treatment planning and management of patients with NSCLC. FDG images using dedicated PET scanners with modern image fusion techniques and respiration-gated acquisition protocols could improve CT/PET image coregistration. However, prospective studies with histological correlation are necessary and the impact on treatment outcome remains to be demonstrated.
    Cancer/Radiothérapie 09/2005; 9(5):304-15. · 1.48 Impact Factor
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    ABSTRACT: Positron emission tomography and computed tomography (PET/CT) have a potential role in detecting and locating recurrent ovarian cancer. Precise tumor location during surgical treatment is often difficult, owing to limited tumor size and post-surgical anatomic modifications. The surgical gamma probe, which has become increasing popular in recent years with the development of sentinel node mapping, may improve tumor detection and facilitate resection of occult metastases. We describe the first case of laparoscopic resection of occult metastasis using the combination of FDG-PET/CT image fusion with intraoperative FDG-sensitive probing in a patient with recurrent ovarian cancer. FDG-sensitive probe combined with preoperative PET/CT image fusion can help to detect occult metastasis and guide laparoscopic excision.
    Gynecologic Oncology 02/2005; 96(1):241-4. · 3.93 Impact Factor
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    ABSTRACT: Before studying the impact of 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) imaging with a dual-head coincidence gamma camera (DHC) for the follow-up of animal tumor models, we wanted to optimize this technique. Three different animal tumor models (osteosarcoma, melanoma, and breast cancer) were studied after FDG injection. Dynamic and dual time point FDG/DHC imaging were studied from one hour to five hours postinjection. In vitro tumor cell FDG uptake was assessed in eight different tumor cell lines. In one model (osteosarcoma), tumor growth, lung metastasis emergence, and survival were assessed by classical clinical follow-up and compared to FDG imaging in a control group (n = 6) and in a group treated by endostatin liposome complexes (n = 6). Images obtained five hours after injection were more reliable for tumor growth follow-up than standard images (one hour). In vitro tumor cell FDG uptake confirmed in vivo imaging studies. In eight different tumor cell lines the FDG uptake was higher after five hours incubation than after one hour (p < 0.002). With FDG follow-up, we found that FDG uptake was strongly correlated with survival and that lung metastasis larger than 5 mm could be detected. Using the optimization proposed above, DHC/FDG functional imaging seems to be a powerful tool to study rat tumor models and to help develop novel cancer therapies.
    Molecular Imaging & Biology 01/2005; 7(3):220-8. · 3.10 Impact Factor
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    ABSTRACT: To assess the clinical performance of fluorodeoxyglucose positron emission tomography (FDG PET) using either a coincidence (CDET) gamma camera or PET equipment with Nal crystals for the detection of recurrences of colorectal cancer. From July 1997 to December 1999, 290 examinations were performed in 244 patients using a CDET gamma camera (2-dimensional system with 19 mm thick crystals). Additionally, from January 2000 to July 2002, 354 examinations were performed in 303 patients using PET (3-dimensional system with Nal crystals). Four hundred and seventy-three of the 644 examinations performed were evaluable on the basis of histological data (202 examinations) or more than 6 months of follow-up (273 examinations). The performances of the two systems were equivalent on a patient basis (sensitivity, specificity and accuracy of dedicated PET was 92%, 84% and 90%, respectively; and sensitivity, specificity and accuracy of CDET was 90%, 94% and 91%, respectively). On a site basis, a highly significant reduction in sensitivity was observed for lesions < or = 10 mm vs. > 10 mm with both PET and the CDET gamma camera, but no difference was observed between PET and CDET according to the size of the lesions. For detection of recurrent colorectal carcinoma, a 2-D coincidence gamma camera with 19 mm thick crystals and optimized acquisition and reconstruction parameters provides similar results in terms of accuracy, both per patient and per site, to those of an Nal PET camera.
    Nuclear Medicine Communications 03/2004; 25(2):105-13. · 1.38 Impact Factor
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    ABSTRACT: Positron Emission Tomography (PET) is a several decade old imaging technique that has more recently demonstrated its utility in clinical applications. The imaging agents used for PET contain a positron emmiter coupled to a molecule that drives the radionuclide to target organs or to tissues performing the targetted biological function. PET is then part of functional imaging. As compared to conventional scintigraphy that uses gamma photons, the coincidence emission of two 511 keV annihilation photons in opposite direction that finally results from by beta plus decay makes it possible for PET to get rid of the collimators that greatly contribute to the poor resolution of scintigraphy. In this article, the authors describe the basics of physics for PET imaging and report on the clinical performances of the most commonly used PET tracer: [18F]-fluorodeoxyglucose (FDG). A recent and promising development in this field is fusion of images coming from different imaging modalities. New PET machines now include a CT and this fusion is therefore much easier.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/2003; · 1.14 Impact Factor
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    ABSTRACT: COLORECTAL CANCERS: FDG-PET is a very effective tool in the follow-up of colorectal cancer for the early detection of recurrences, the search for other localisations in case of resectable lesions and for the evaluation of therapies. For the other digestive cancers, the data in the literature are less abundant and they do not yet have Marketing Authorization in France. OESOPHAGEAL CANCER: FDG-PET appears very promising for staging and detection of recurrences of oesophageal carcinomas. Pancreatic cancer Although the indication is difficult, FDG-PET appears superior to morphological techniques for the characterization and the locoregional staging of pancreatic tumours. BILARY AND GASTRIC CARCINOMAS: FDG-PET is promising but its role has to be confirmed in larger series for the detection of biliary and gastric carcinomas. OTHER DIGESTIVE TUMOURS: In cases of hepatocarcinoma, FDG-PET appears efficient only in cases of undifferentiated tumours, and in cases of malignant neuroendocrine digestive tumours, is useful in combination with somatostatin receptor imaging.
    La Presse Médicale 11/2002; 31(33):1560-8. · 0.87 Impact Factor
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    ABSTRACT: Although gynaecological cancers are not currently part of the clinical indications in the French registration for [18F]-fluoro-2-deoxyglucose (FDG), various studies indicate in this context a potential clinical benefit of imaging with this radiopharmaceutical and PET, a new imaging modality that can be performed either with a dedicated machine or with a "hybrid" gamma-camera (CDET). The potential indications of FDG-PET in mammary, ovarian or cervical cancers are reviewed according to the diagnostic phase: screening, tumour characterisation, staging, therapeutic follow-up and search for recurrence. By pooling the published results, the accuracy of FDG-PET could be estimated with a reasonable precision in various clinical settings: characterisation of a breast tumour (598/696 = 86%), lymph node invasion in breast cancer (525/602 = 87%), recurrence of breast cancer (114/127 = 90%), characterisation of adnexal masses (130/176 = 78%), recurrence of ovarian cancer (152/172 = 88%), lymph node invasion in cervical cancer (98/103 = 95%). Authors also present original data concerning their experience of recurrence detection with CDET in breast or ovarian cancers. In 44 patients suspicious of recurrence of breast cancer, FDG-CDET sensitivity was 94%, specificity 82% and accuracy 91%; in 18 patients suspicious of recurrence of ovarian cancer, specificity, sensitivity and accuracy were 100%. The impact of dedicated PET and CDET examinations performed by our team during year 2000, led, according to 63 forms returned to us, to a modification of stage in 48% of breast cancers, 36% of ovarian cancers, 43% of cervical cancers and above all induced a modification in patients' management in respectively 69%, 64% and 60% of cases, more than the average rate in cancer patients which was 50%. No significant difference was observed between clinical impact of dedicated PET and CDET examinations.
    Gynécologie Obstétrique & Fertilité 12/2001; 29(11):775-98. · 0.55 Impact Factor
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    ABSTRACT: The recent evolutions of the imaging modalities, the dose calculation models, the linear accelerators and the portal imaging permit to improve the quality of the conformal radiation therapy treatment planning. With DICOM protocols, the acquired imaging data coming from different modalities are treated by performant image fusion algorithms and yield more precise target volumes and organs at risk. The transformation of the clinical target volumes (CTV) to planning target volumes (PTV) can be realised using advanced probabilistic techniques based on clinical experience. The treatment plans evaluation is based on the dose volume histograms. Their precision and clinical relevance are improved by the multi-modality imaging and the advanced dose calculation models. The introduction of the inverse planning systems permitting to realise modulated intensity radiation therapy generates highly conformal dose distributions. All the previously cited complex techniques require the application of rigorous quality assurance programs.
    Cancer/Radiothérapie 11/2001; 5(5):496-514. · 1.48 Impact Factor
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    ABSTRACT: This review of the different methodologies used for animal imaging with radioactive compounds presents the most recent approaches developed for both in vitro and in vivo studies. The choice of a detector for analysis of the spatial distribution of radionuclides deposited in biological tissues results in a trade-off between the size and nature of the region to study (in vitro or in vivo), the required spatial resolution and the penetrating characteristics of the ionizing radiation. Real time detectors are now available for quantitative imaging of 2D or 3D radioactive samples and offer either an increased dynamic range or a lowered sensitivity in comparison with film radioautography. For high resolution imaging, two specific techniques are proposed for applications to rodents. The usefulness of self-triggering intensified charge coupled device (STIC) is illustrated for in vitro localization in radiotoxicological studies of alpha-emitters. For in vivo techniques, the performance of positron emission tomography (PET) is discussed, as a promising method of molecular imaging of biological processes.
    Cellular and molecular biology 06/2001; 47(3):443-51. · 0.81 Impact Factor