S. Querellou

European University of Brittany, Roazhon, Brittany, France

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Publications (42)59.78 Total impact

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    ABSTRACT: The aim of this management outcome study was to assess the safety of ventilation/perfusion single photon emission computed tomography (V/Q SPECT) for the diagnosis of pulmonary embolism (PE) using for interpretation the criteria proposed in the European Association of Nuclear Medicine (EANM) guidelines for V/Q scintigraphy. A total of 393 patients with clinically suspected PE referred to the Nuclear Medicine Department of Brest University Hospital from April 2011 to March 2013, with either a high clinical probability or a low or intermediate clinical probability but positive D-dimer, were retrospectively analysed. V/Q SPECT were interpreted by the attending nuclear medicine physician using a diagnostic cut-off of one segmental or two subsegmental mismatches. The final diagnostic conclusion was established by the physician responsible for patient care, based on clinical symptoms, laboratory test, V/Q SPECT and other imaging procedures performed. Patients in whom PE was deemed absent were not treated with anticoagulants and were followed up for 3 months. Of the 393 patients, the prevalence of PE was 28 %. V/Q SPECT was positive for PE in 110 patients (28 %) and negative in 283 patients (72 %). Of the 110 patients with a positive V/Q SPECT, 78 (71 %) had at least one additional imaging test (computed tomography pulmonary angiography or ultrasound) and the diagnosis of PE was eventually excluded in one patient. Of the 283 patients with a negative V/Q SPECT, 74 (26 %) patients had another test. The diagnosis of PE was finally retained in one patient and excluded in 282 patients. The 3-month thromboembolic risk in the patients not treated with anticoagulants was 1/262: 0.38 % (95 % confidence interval 0.07-2.13). A diagnostic management including V/Q SPECT interpreted with a diagnostic cut-off of "one segmental or two subsegmental mismatches" appears safe to exclude PE.
    European Journal of Nuclear Medicine 04/2014; · 4.53 Impact Factor
  • Médecine Nucléaire. 05/2013; 37(5):139–140.
  • Médecine Nucléaire. 05/2013; 37(5):150.
  • Médecine Nucléaire. 05/2013; 37(5):143.
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    ABSTRACT: OBJECTIVE: The objective of this study was to investigate the independent prognostic value of dual-time-point F-fluorodeoxyglucose (F-FDG) PET-CT imaging in patients with head and neck squamous cell carcinoma (HNSCC). METHODS: Patients referred to our department to undergo F-FDG PET-CT for staging of HNSCC were prospectively included. Each patient was scanned using a Philips Gemini PET-CT system 1 h (early acquisition) and 2 h (delayed acquisition) after injection. An intratumoral retention index (RI) of F-FDG was measured for each examination by the dual-time-point method. Event-free survival (EFS) and overall survival (OS) were determined by the Kaplan-Meier method and compared with the conventional maximum standardized uptake value (SUVmax) at 60 min, SUVmax at 120 min, and RI in univariate and multivariate analyses including the usual prognostic factors such as age, sex, primary site, SCC histologic grade, and American Joint Committee on Cancer stage (I, II, III, and IV). RESULTS: Sixty-six consecutive patients (60 men and six women; mean age=61±9 years) were included in the study. In univariate analysis, besides age and stage, RI was predictive of EFS (P=0.01) but not of OS (P=0.1), whereas SUVmax at 60 min was not predictive of EFS (P=0.18) or OS (P=0.08) and SUVmax at 120 min was predictive of OS (P=0.02) but not of EFS (P=0.05). In multivariate analysis, RI persisted as an independent predictive factor for EFS (P=0.02) but not SUVmax at 120 min for OS (P=0.12). CONCLUSION: Our results suggest an additional prognostic interest of RI measured by dual-time-point F-FDG PET-CT, independent of usual prognostic factors, in patients with HNSCC.
    Nuclear Medicine Communications 04/2013; · 1.38 Impact Factor
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    ABSTRACT: Background The diagnosis of wrist fractures, especially scaphoid fractures, remains a challenge because of non-union risk. Currently new hybrid technologies are emerging such as single photon emission computed tomography–computed tomography (SPECT/CT) systems, which combine functional and anatomical data sets. So, we wanted to evaluate the utility of SPECT/CT in the management of occult carpal fractures.Patients and methodsAll patients addressed to the orthopaedic department at Brest University Hospital for wrist pain after trauma and with initial normal plain radiographs were prospectively included. Patients with normal radiographs but a strong suspicion of clinical fracture underwent a bone SPECT/CT and an MRI of the wrist. Therapeutic management took into account the results of all modalities and all patients were followed for at least 6 months and reviewed by the same surgeon. SPECT/CT findings were compared to those of the other modalities and follow-up.ResultsFrom December 2009 to May 2011, 57 patients were enrolled. Fifty-seven SPECT/CT and 52 MRI were performed. Twenty-six patients presented a positive SPECT/CT (31 fractures). MRI concluded to abnormalities for 26 patients (20 fractures and 17 bone bruises). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy per patient were respectively 88.46%, 96.15%, 95.83%, 89.29%, 92.3% and per lesion 75.68%, 96.15%, 96.55%, 73.53%, 84.13%. Interobserver reproducibility for SPECT/CT was excellent. Only one patient presented a non-union at the follow-up whereas both investigations were positive.Conclusion This study highlights the good performances of SPECT/CT, which allows the detection of most occult carpal fractures. When a carpal occult fracture is clinically strongly suspected, SPECT/CT might be proposed in first intention after normal radiographs.
    Médecine Nucléaire. 04/2013; 37(4):105–115.
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    ABSTRACT: BACKGROUND: The diagnosis of wrist fractures, especially scaphoid fractures, remains a challenge because of nonunion risk. Currently, new hybrid technologies are emerging such as SPECT/CT systems, which combine functional and anatomical data sets. So, we wanted to evaluate the utility of SPECT/CT in the management of occult carpal fractures. METHODS: In this study, all patients addressed at the orthopedic department at Brest University Hospital for wrist pain after trauma with initial normal plain radiographs were prospectively included. Patients with normal radiographs but with signs strongly suggestive of clinical fracture underwent a bone SPECT/CT and an MRI of the wrist. Therapeutic management took into account the results of all modalities, and all patients were followed up for at least 6 months and reviewed by the same surgeon. SPECT/CT findings were compared with those of the other modalities and follow-up. RESULTS: From December 2009 to May 2011, 57 patients were enrolled. Fifty-seven SPECT/CT and 52 MRI scans were obtained. Twenty-eight patients had normal imaging results, whereas 29 patients presented bone bruise and/or fractures. Ten patients were concordant according to SPECT/CT and MRI; 2 patients presented fractures on SPECT/CT without MRI performed; 17 patients had partially discordant results. Only 1 patient presented a nonunion at the follow-up, whereas both investigations were positive. CONCLUSIONS: This study highlights the good performances of SPECT/CT, which allows the detection of most occult carpal fractures. When a carpal occult fracture is strongly suspected clinically, SPECT/CT might be proposed at first intention after normal radiographs.
    Clinical nuclear medicine 03/2013; · 3.92 Impact Factor
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    ABSTRACT: Objective To assess the added benefit of scanning lower limbs in addition to usual whole-body PET/CT scan in patients with no known or suspected primary or metastatic melanoma involving the lower limbs.Materials and methodsThis is a retrospective study of 133 consecutive patients (189 FDG PET/CT) who underwent FDG PET/CT for staging of melanoma at different time points in the course of disease from October 2005 to July 2009 at Brest University Hospital. Reports of whole-body PET/CT scans including lower limbs were reviewed. PET/CT abnormalities on the lower extremities were tabulated by location and correlated with pathology, other imaging studies and at least a 6-month clinical follow-up.ResultsAmong the 189 consecutive PET/CT scans performed in 133 patients, 34 scans in 29 patients highlighted abnormal FDG uptakes considered as equivocal or suggestive of malignancy on lower limbs. In 29 cases, uptakes were located both on lower limbs and on the rest of the body (lung, liver, mediastinal and sub-diaphragmatic lymph nodes, adrenal glands, bone) corresponding to disseminated disease. In five cases, PET/CT uptakes were located only on lower limbs; each pathological uptake corresponded to benign lesions. Lower limbs findings never impacted clinical and therapeutic decision.Conclusion Lower limbs additional PET/CT acquisition appears to offer poor additional benefit with no unexpected solitary lesion detected and routine skull base to upper thigh images may be sufficient for this subset of patients.
    Médecine Nucléaire. 02/2013; 37(2):26–34.
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    ABSTRACT: Lung cancer is a major public health problem that generates a large number of imaging and acts for diagnostic procedures. The last decade saw the development of positron emission tomography coupled to the scanner (PET/CT), which has significantly improved the staging and allowed to obtain better accuracy in the initial staging. It may change the management of a patient thanks to a better characterization of the initial situation. Several series have to assess performance, often higher than that of CT and there are several recommendations specifying the place of this examination in the management of lung cancer. It also seems to become a complementary tool to the radiotherapist for delineation of volumes to be irradiated using functional information of the tumor. The concept of biological target volume (BTV) has been introduced. There are more perspectives for diagnostic, therapeutic evaluation and prognosis with the study of new tracers, including those of hypoxia and cell proliferation.
    Médecine Nucléaire. 01/2013; 37(8):313–319.
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    ABSTRACT: PURPOSE: Locally advanced head and neck squamous cell carcinoma (HNSCC) has a high rate of recurrence. Induction chemotherapy with DCF (docetaxel, cisplatin, 5-fluorouracil) before chemoradiotherapy could lead to the best disease control of inoperable stage III/IV HNSCC but with an increased risk of acute toxicity. Early assessment of therapeutic efficacy is a key issue in considering the benefit of escalation in a poor prognosis population. METHODS: Patients with stage III/IV HNSCC, in whom DCF induction chemotherapy followed by concurrent chemoradiotherapy had been validated by a multidisciplinary team, were prospectively included in the study. FDG PET/CT scans were performed in all patients before and after two of the three cycles of DCF. EORTC99 criteria were used to evaluate PET responses as follows: group 1 (metabolic responders) showing a complete response (CR) or partial response (PR), and subgroup 0 (metabolic nonresponders) showing stable disease (SD) or progressive disease (PD). The primary endpoint for monitoring patients was event-free survival (EFS). EFS probabilities between the two groups were estimated by the Kaplan-Meier method and statistically compared using the log-rank test. RESULTS: Fifteen consecutive patients (14 men, 1 woman; age 57.5 ± 6.2 years, mean ± SD) were analysed. Therapeutic assessment by PET/CT demonstrated CR in four patients, PR in six, SD in four and PD in one. Among the ten patients with a metabolic response (group 1), none had relapsed at the time of this report, while four of five patients with no metabolic response (group 0) showed recurrence within an average of 9.0 ± 1.6 months. Median EFS was, respectively, 18.9 months (3.8-25.3 months) and 10.2 months (7.5-12.7 months) in group 1 and group 0. The corresponding 1-year EFS rates were 100 % and 20 %, respectively. The difference in EFS between the two groups was statistically significant (p = 0.0014). CONCLUSION: Early therapeutic response demonstrated on FDG PET/CT after two cycles of induction chemotherapy with DCF in patients with inoperable stage III/IV HNSCC seems to be a predictive factor for EFS.
    European Journal of Nuclear Medicine 08/2012; · 4.53 Impact Factor
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    ABSTRACT: IntroductionTo assess interobserver variability for biological target volume (BTV) delineation and to compare the reproductibility of different semiautomatic segmentation methods in pretreatment 18-fluorodeoxyglucose positron emission tomography (PET/CT) of head and neck squamous cell carcinoma (HNSCC).Patients and methodsPatients with histologically proved HNSCC referred to the nuclear medicine service in Brest for pretreatment PET/CT were prospectively included from February 2009 to June 2010. Three nuclear medicine physicians (two specialized in oncology) delineated manually and independently BTV on each primary tumor. Four semiautomatic segmentation methods have been studied; three using a fixed threshold and one applying an adaptive threshold based on the signal-to-background ratio (Daisne). The variability between κ observers and/or methods has been assessed. The concordance between the various BTV intersections and unions has been also assessed.ResultsThirty patients (29M; 1F) were included. The primary site location was oropharynx in six patients, oral cavity in 10 patients, hypopharynx in five patients and larynx in nine patients. A statistically significant global interobserver variability (P = 0.01) was showed, but without statistically difference between the two experienced oncologists (P = 0.15). The maximal concordance of the two experienced observers with the semiautomatic methods was found for the Daisne method (CI = 61.5%; κ = 0.68), expressing a good agreement according to the Landis and Koch criteria, better than with the segmentation method using a fixed threshold with 40% of maximal signal intensity (CI = 52.1%; κ = 0.53).Conclusion Our results suggest the feasibility of achieving HNSCC BTV delineation by PET/CT using semiautomatic methods, in particular those which apply an adaptative threshold but under the supervision of an experienced operator.
    Médecine Nucléaire. 06/2012; 36(6):303–312.
  • Médecine Nucléaire. 04/2012; 36(4):167.
  • Médecine Nucléaire. 04/2012; 36(4):176.
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    ABSTRACT: The use of summed planar images generated from single-photon emission computed tomography (SPECT) ventilation/perfusion (V/Q) scintigraphy has been proposed as a substitute for planar V/Q scans in order to use the revised PIOPED interpretation criteria when only SPECT acquisition is performed in patients with suspected pulmonary embolism. The aim was to evaluate the accuracy of angular summed planar scans in comparison with true planar images. Patients included in the 'SPECT study' assessing the diagnostic performance of V/Q SPECT were analysed. Angular summed planar images were generated from SPECT acquisition data and compared with true planar scans. Angular summed planar images were successfully generated for 246 patients. Regarding interobserver variability, the interpretation result was different for 15 (6%) summed planar scans with an excellent degree of agreement (κ=0.92; 95% confidence interval 0.88-0.96). With regard to intermodality interpretation variability between conventional planar and angular summed images, the result was different for 63 (26%) of 246 patients with an intermodality degree of agreement of κ=0.66 (95% confidence interval 0.58-0.73). Planar images generated from SPECT V/Q scintigraphy are not a reliable substitute for true planar V/Q images.
    Nuclear Medicine Communications 03/2012; 33(7):695-700. · 1.38 Impact Factor
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    ABSTRACT: The potential predictive value of tumor bulk, genetic, and immunological variants in patients with low-grade non-Hodgkin's lymphoma to respond to treatment with rituximab (RTX) monotherapy was evaluated. Thus, the value of assessing the effect of 18-fluoro-desoxy-D-glucose (FDG) uptake on PET scan, polymorphisms in Fc gamma receptor (FcγR) IIIa-158, FcγRIIa-131, and C1qA-276 genes in predicting the response to treatment were evaluated in 50 low-grade non-Hodgkin's lymphoma patients. The influence of RTX pharmacokinetics, plasma levels of the B cell-activating factor (BAFF), and human antichimeric antibodies was also investigated. The therapeutic response was evaluated 10 weeks after treatment using revised Cheson's criteria. Lower maximal standardized uptake values (SUV(max)) at baseline were predictive of complete response. FcγRIIIa-158 polymorphism was also associated with complete response to RTX confirming previous findings, whereas polymorphisms in the FcγRIIa-131 and C1qA-276 genes were not. Lower blood levels of RTX were observed in males, but the effectiveness of RTX in males and females was the same. BAFF was not detectable in plasma before or after treatment, and no patients developed human antichimeric antibodies. Low-grade non-Hodgkin's lymphoma patients with a low SUV(max) at baseline and an FcγRIIIa-158 V/V genotype generally had a complete response to RTX.
    Annals of Hematology 11/2011; 91(5):715-21. · 2.87 Impact Factor
  • Solene Querellou
    Nuclear Medicine Communications 09/2011; 32(9):873. · 1.38 Impact Factor
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    ABSTRACT: High tumor uptake of fluorodeoxyglucose (FDG) is associated with an unfavorable outcome in patients with cancer. We evaluated FDG uptake as a prognostic factor in patients with head and neck squamous cell carcinoma. Maximum standardized uptake values (SUVmax) of tumor, liver, and pulmonary artery were recorded. Ratios of SUVmax from tumor to liver (T/L) and from tumor to pulmonary artery (T/PA) were calculated for each patient. Clinical data, tumor, and SUVmax ratios were compared with disease-free survival (DFS) and overall survival (OS). Eighty-nine patients were included: 48 presented a local recurrent disease or distant metastases and 42 died. For both DFS and OS, tumor SUVmax value of 7 was the best cutoff value and 4 and 5 for T/L and T/PA ratios. Multivariate analysis confirmed the independent prognostic value of these 3 thresholds for DFS and OS. FDG uptake has a significant and independent relationship with recurrence and survival.
    Head & Neck 05/2011; 34(4):462-8. · 2.83 Impact Factor
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    ABSTRACT: Interim 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) has shown to be an accurate predictor of prognosis in Hodgkin's lymphoma (HL). However, FDG PET response criteria are a matter of ongoing debate. The aim of this study was to confirm the prognostic value of interim PET/CT in HL patients treated with an interim response-adapted strategy and to compare the respective performances of different published criteria. Newly diagnosed patients with HL underwent interim PET/CT after four courses of Adriamycin, bleomycin, vinblastine and dacarbazine (ABVD). The treatment strategy was adapted according to prognostic factors at diagnosis and interim PET/CT and CT results. PET images were prospectively interpreted visually: a negative result was defined as no residual uptake above local background. All other findings were considered as positive. Retrospectively, interim PET/CT was analysed according to International Harmonization Project (IHP), Gallamini and London criteria The analysis included 90 patients; 6 of 31 patients with positive interim PET/CT and 7 of 59 patients with negative interim result presented treatment failure. The negative predictive value (NPV) and positive predictive value (PPV) for predicting 2-year progression-free survival (PFS) was 95 and 16%, respectively. With the other criteria, NPV remained very high (from 95 to 96%). The PPV increased from 19 to 45% according to the threshold used. Interim PET/CT was significantly correlated with PFS with Gallamini (p = 0.01) and London criteria (p < 0.0001). Our study confirms the high NPV of interim PET/CT for predicting treatment outcome in HL and a probably better prognostic value using a higher threshold for positivity even after four cycles of chemotherapy as used in Gallamini and London criteria.
    European Journal of Nuclear Medicine 02/2011; 38(6):1064-71. · 4.53 Impact Factor
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    ABSTRACT: PurposeAssociation of venous thromboembolism (VTE) and inflammation reported in the literature may allow the use of FDG PET/CT in the detection of thrombotic process. Published studies remain limited and contradictory. The aim was, therefore, to evaluate the performance of FDG PET/CT for the detection of VTE.
    Medecine Nucleaire-imagerie Fonctionnelle Et Metabolique - MED NUCL. 01/2011; 35(4):179-185.
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    ABSTRACT: 18Fluoro-deoxyglucose (FDG) positron emission tomography (PET) is an imaging technique which studies the cellular glucidic metabolism. It is particularly indicated in oncology, especially for cancer diagnosis (with a potential prognosis interest) or detection of recurrence. Because of its functional approach to the tissues, its use has logically evolved into the evaluation of cancer treatments, both for the individual care of patients for clinical trials of new therapies. Also, it tends to displace conventional imaging in this indication, whose main limitation is not to assess the viability of residual masses, potentially necrotic or fibrous after treatment. However, the use of FDG-PET requires a rigorous methodology for both the exams achievement but also for the quality of their interpretation, including the choice of the comparison tool. Based on an increasing literature on the subject, were published and updated interpretation criteria for both lymphoma and solid cancers. For lymphoma, standardized assessment criteria were proposed in 2007 during an International Harmonize Project (IHP). For solid cancers, Positron Emission tomography Response Criteria In Solid Tumors (PERCIST) recommendations version 1.0 were recently proposed by an American workshop in 2009 in order to clarify and standardize practices.
    Medecine Nucleaire-imagerie Fonctionnelle Et Metabolique - MED NUCL. 01/2011; 35(11):600-607.