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Dive into the research topics where Gilles Allenbach is active.

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Featured researches published by Gilles Allenbach.


European Journal of Echocardiography | 2013

Added prognostic value of myocardial blood flow quantitation in rubidium-82 positron emission tomography imaging.

Hoshang Farhad; Vincent Dunet; Kim Bachelard; Gilles Allenbach; Philipp A. Kaufmann; John O. Prior

AIMS We studied the respective added value of the quantitative myocardial blood flow (MBF) and the myocardial flow reserve (MFR) as assessed with (82)Rb positron emission tomography (PET)/CT in predicting major adverse cardiovascular events (MACEs) in patients with suspected myocardial ischaemia. METHODS AND RESULTS Myocardial perfusion images were analysed semi-quantitatively (SDS, summed difference score) and quantitatively (MBF, MFR) in 351 patients. Follow-up was completed in 335 patients and annualized MACE (cardiac death, myocardial infarction, revascularization, or hospitalization for congestive heart failure or de novo stable angor) rates were analysed with the Kaplan-Meier method in 318 patients after excluding 17 patients with early revascularizations (<60 days). Independent predictors of MACEs were identified by multivariate analysis. During a median follow-up of 624 days (inter-quartile range 540-697), 35 MACEs occurred. An annualized MACE rate was higher in patients with ischaemia (SDS >2) (n = 105) than those without [14% (95% CI = 9.1-22%) vs. 4.5% (2.7-7.4%), P < 0.0001]. The lowest MFR tertile group (MFR <1.8) had the highest MACE rate [16% (11-25%) vs. 2.9% (1.2-7.0%) and 4.3% (2.1-9.0%), P < 0.0001]. Similarly, the lowest stress MBF tertile group (MBF <1.8 mL/min/g) had the highest MACE rate [14% (9.2-22%) vs. 7.3% (4.2-13%) and 1.8% (0.6-5.5%), P = 0.0005]. Quantitation with stress MBF or MFR had a significant independent prognostic power in addition to semi-quantitative findings. The largest added value was conferred by combining stress MBF to SDS. This holds true even for patients without ischaemia. CONCLUSION Perfusion findings in (82)Rb PET/CT are strong MACE outcome predictors. MBF quantification has an added value allowing further risk stratification in patients with normal and abnormal perfusion images.


Nuklearmedizin-nuclear Medicine | 2012

18F-fluorodeoxyglucose PET/CT findings in pleural effusions of patients with known cancer: A cytopathological correlation

Igor Letovanec; Gilles Allenbach; A. Mihaescu; M. Nicod Lalonde; Sabine Schmidt; Roger Stupp; J.-W. Fitting; Ariane Boubaker; Hans-Beat Ris; John O. Prior

AIM Pleural effusion is common in cancer patients and to determine its malignant origin is of huge clinical significance. PET/CT with ¹⁸F-FDG is of diagnostic value in staging and follow-up, but its ability to differentiate between malignant and benign effusions is not precisely known. PATIENTS, METHODS We examined 50 PET/CT from 47 patients (29 men, 18 women, 60 ± 16 years) with pleural effusion and known cancer (24 NSCLC, 7 lymphomas, 5 breasts, 4 GIST, 3 mesotheliomas, 2 head and neck, 2 malignant teratoma, 1 colorectal, 1 oesophageal, 1 melanoma) for FDG uptake in the effusions using SUV(max). This was correlated to cytopathology performed after a median of 21 days (interquartile range -3 to 23), which included pH, relative distribution (macrophages, neutrophils, eosinophils, basophils, lymphocytes, plasmocytes), and absolute cell count. RESULTS Malignant cells were found in 17 effusions (34%) (6 NSCLC, 5 lymphomas, 2 breasts, 2 mesotheliomas, 2 malignant teratomas). SUV in malignant effusions were higher than in benign ones [3.7 (95%CI 1.8-5.6) vs. 1.7 g/ml (1.5-1.9), p = 0.001], with a correlation between malignant effusion and SUV (Spearman coefficient r = 0.50, p = 0.001), but not with other cytopathological or radiological parameters (ROC area 0.83 ± 0.06). Using a 2.2-mg/l SUV threshold, 12 PET/CT studies were positive and 38 negative with sensitivity, specificity, positive and negative predictive values of 53%, 91%, 75% and 79%, respectively. For NSCLC only (n = 24), ROC area was 0.95 ± 0.04, 7 studies were positive and 17 negative with a sensitivity, specificity, positive and negative predictive values of 83%, 89%, 71 and 94%, respectively. CONCLUSION PET/CT may help to differentiate the malignant or benign origin of a pleural effusion with a high specificity in patients with known cancer, in particular NSCLC.


Interactive Cardiovascular and Thoracic Surgery | 2009

Value of positron emission tomography in full-thickness chest wall resections for malignancies.

David Petermann; Gilles Allenbach; Sabine Schmidt; Igor Letovanec; Michel Christodoulou; Angelika Bischof Delaloye; Hans-Beat Ris; John O. Prior

Preoperative imaging for resection of chest wall malignancies is generally performed by computed tomography (CT). We evaluated the role of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in planning full-thickness chest wall resections for malignancies. We retrospectively included 18 consecutive patients operated from 2004 to 2006 at our institution. Tumor extent was measured by CT and PET, using the two largest perpendicular tumor extensions in the chest wall plane to compute the tumor surface assuming an elliptical shape. Imaging measurements were compared to histopathology assessment of tumor borders. CT assessment consistently overestimated the tumor size as compared to PET (+64% vs. +1%, P<0.001). Moreover, PET was significantly better than CT at defining the size of lesions >24 cm(2) corresponding to a mean diameter >5.5 cm or an ellipse of >4 cm x 7.6 cm (positive predictive value 80% vs. 44% and specificity 93% vs. 64%, respectively). Metabolic PET imaging was superior to CT for defining the extent of chest wall tumors, particularly for tumors with a diameter >5.5 cm. PET can complement CT in planning full-thickness chest wall resection for malignancies, but its true value remains to be determined in larger, prospective studies.


Nuklearmedizin | 2012

18F-fluorodeoxyglucose PET/CT findings in pleural effusions of patients with known cancer

Igor Letovanec; Gilles Allenbach; A. Mihaescu; M. Nicod Lalonde; Sabine Schmidt; Roger Stupp; J.-W. Fitting; Ariane Boubaker; Hans-Beat Ris; John O. Prior

AIM Pleural effusion is common in cancer patients and to determine its malignant origin is of huge clinical significance. PET/CT with ¹⁸F-FDG is of diagnostic value in staging and follow-up, but its ability to differentiate between malignant and benign effusions is not precisely known. PATIENTS, METHODS We examined 50 PET/CT from 47 patients (29 men, 18 women, 60 ± 16 years) with pleural effusion and known cancer (24 NSCLC, 7 lymphomas, 5 breasts, 4 GIST, 3 mesotheliomas, 2 head and neck, 2 malignant teratoma, 1 colorectal, 1 oesophageal, 1 melanoma) for FDG uptake in the effusions using SUV(max). This was correlated to cytopathology performed after a median of 21 days (interquartile range -3 to 23), which included pH, relative distribution (macrophages, neutrophils, eosinophils, basophils, lymphocytes, plasmocytes), and absolute cell count. RESULTS Malignant cells were found in 17 effusions (34%) (6 NSCLC, 5 lymphomas, 2 breasts, 2 mesotheliomas, 2 malignant teratomas). SUV in malignant effusions were higher than in benign ones [3.7 (95%CI 1.8-5.6) vs. 1.7 g/ml (1.5-1.9), p = 0.001], with a correlation between malignant effusion and SUV (Spearman coefficient r = 0.50, p = 0.001), but not with other cytopathological or radiological parameters (ROC area 0.83 ± 0.06). Using a 2.2-mg/l SUV threshold, 12 PET/CT studies were positive and 38 negative with sensitivity, specificity, positive and negative predictive values of 53%, 91%, 75% and 79%, respectively. For NSCLC only (n = 24), ROC area was 0.95 ± 0.04, 7 studies were positive and 17 negative with a sensitivity, specificity, positive and negative predictive values of 83%, 89%, 71 and 94%, respectively. CONCLUSION PET/CT may help to differentiate the malignant or benign origin of a pleural effusion with a high specificity in patients with known cancer, in particular NSCLC.


Nuklearmedizin | 2012

Identifikation maligner Pleura-Ergüsse mittels 18F-Fluordeoxyglukose-PET/CT – Eine Korrelation mit zytopathologischen Befunden

Igor Letovanec; Gilles Allenbach; A. Mihaescu; M. Nicod Lalonde; Sabine Schmidt; Roger Stupp; J.-W. Fitting; Ariane Boubaker; Hans-Beat Ris; John O. Prior

AIM Pleural effusion is common in cancer patients and to determine its malignant origin is of huge clinical significance. PET/CT with ¹⁸F-FDG is of diagnostic value in staging and follow-up, but its ability to differentiate between malignant and benign effusions is not precisely known. PATIENTS, METHODS We examined 50 PET/CT from 47 patients (29 men, 18 women, 60 ± 16 years) with pleural effusion and known cancer (24 NSCLC, 7 lymphomas, 5 breasts, 4 GIST, 3 mesotheliomas, 2 head and neck, 2 malignant teratoma, 1 colorectal, 1 oesophageal, 1 melanoma) for FDG uptake in the effusions using SUV(max). This was correlated to cytopathology performed after a median of 21 days (interquartile range -3 to 23), which included pH, relative distribution (macrophages, neutrophils, eosinophils, basophils, lymphocytes, plasmocytes), and absolute cell count. RESULTS Malignant cells were found in 17 effusions (34%) (6 NSCLC, 5 lymphomas, 2 breasts, 2 mesotheliomas, 2 malignant teratomas). SUV in malignant effusions were higher than in benign ones [3.7 (95%CI 1.8-5.6) vs. 1.7 g/ml (1.5-1.9), p = 0.001], with a correlation between malignant effusion and SUV (Spearman coefficient r = 0.50, p = 0.001), but not with other cytopathological or radiological parameters (ROC area 0.83 ± 0.06). Using a 2.2-mg/l SUV threshold, 12 PET/CT studies were positive and 38 negative with sensitivity, specificity, positive and negative predictive values of 53%, 91%, 75% and 79%, respectively. For NSCLC only (n = 24), ROC area was 0.95 ± 0.04, 7 studies were positive and 17 negative with a sensitivity, specificity, positive and negative predictive values of 83%, 89%, 71 and 94%, respectively. CONCLUSION PET/CT may help to differentiate the malignant or benign origin of a pleural effusion with a high specificity in patients with known cancer, in particular NSCLC.


EJNMMI research | 2011

Effects of paraoxonase activity and gene polymorphism on coronary vasomotion

Vincent Dunet; Juan Ruiz; Gilles Allenbach; Paola Izzo; Richard William James; John O. Prior

BackgroundParaoxonase 1 [PON1] is recognized as a protective enzyme against LDL oxidation, and PON1 polymorphism has been described as a factor influencing coronary heart disease [CHD] free survival. As coronary vasoreactivity is a surrogate of future cardiovascular events, we aimed at assessing the respective effect of the PON1 genotype and activity on coronary vasoreactivity in a population of type 2 diabetic patients.MethodsNineteen patients with type 2 diabetes mellitus underwent 82Rb cardiac PET/CT to quantify myocardial blood flow [MBF] at rest, during cold pressor testing [CPT], and during adenosine-induced hyperaemia to compute myocardial flow reserve [MFR]. They were allocated according to Q192R and L55M polymorphisms into three groups (wild-type and LM/QR heterozygotes, MM homozygotes, and RR homozygotes) and underwent a measurement of plasmatic PON1 activity. Relations between rest-MBF, stress-MBF, MFR, and MBF response to CPT and PON1 genotypes and PON1 activity were assessed using Spearmans correlation and multivariate linear regression analysis.ResultsAlthough PON1 activity was significantly associated with PON1 polymorphism (p < 0.0001), there was no significant relation between the PON1 genotypes and the rest-MBF, stress-MBF, or MBF response to CPT (p ≥ 0.33). The PON1 activity significantly correlated with the HDL plasma level (ρ = 0.63, p = 0.005), age (ρ = -0.52, p = 0.027), and MFR (ρ = 0.48, p = 0.044). Moreover, on multivariate analysis, PON1 activity was independently associated with MFR (p = 0.037).ConclusionOur study supports an independent association between PON1 activity and MFR. Whether PON1 contributes to promote coronary vasoreactivity through its antioxidant activity remains to be elucidated. This putative mechanism could be the basis of the increased risk of CHD in patients with low PON1 activity.


Journal of Neuroimmunology | 2016

FDG-PET hyperactivity pattern in anti-NMDAr encephalitis

Jan Novy; Gilles Allenbach; Christian G. Bien; Eric Guedj; John O. Prior; Andrea O. Rossetti

FDG-PET can show anteroposterior glucose metabolism gradient in anti-NMDAr encephalitis, but there are also suggestions that basal ganglia are involved. We examined FDG-PET scans in 5 consecutive episodes of serologically proven anti-NMDAr encephalitis, compared with healthy controls. We confirmed the anteroposterior metabolic gradient and found a significant FDG uptake increase in the caudate nuclei in episodes of varying intensity and delay from the onset of the symptoms. FDG-PET can be useful in the work-up of suspected anti-NMDAr encephalitis disclosing a characteristic cortical and sub-cortical metabolism pattern.


Psychotherapy Research | 2018

Dialectical behavior therapy skills training affects defense mechanisms in borderline personality disorder: An integrative approach of mechanisms in psychotherapy

Sebastian Euler; Esther Stalujanis; Gilles Allenbach; Stéphane Kolly; Yves de Roten; Jean-Nicolas Despland; Ueli Kramer

Abstract Objective: Borderline personality disorder (BPD) is characterized by immature defense mechanisms. Dialectical behavior therapy (DBT) is an effective treatment for BPD. However, understanding the underlying mechanisms of change is still limited. Using a transtheoretical framework, we investigated the effect of DBT skills training on defense mechanisms. Method: In this randomized controlled trial, 16 of 31 BPD outpatients received DBT skills training adjunctive to individual treatment as usual (TAU), while the remaining 15 received only individual TAU. Pre–post changes of defense mechanisms, assessed with the Defense Mechanism Rating Scale, were compared between treatment conditions using ANCOVAs. Partial correlations and linear regressions were conducted to explore associations between defenses and symptom outcome. Results: Overall defense function improved significantly more in the skills training condition (F(1, 28) = 4.57, p = .041). Borderline defenses decreased throughout skills training, but not throughout TAU only (F(1, 28) = 5.09, p = .032). In the skills training condition, an increase in narcissistic defenses was associated with higher symptom scores at discharge (β = 0.58, p = .02). Conclusions: Although DBT does not explicitly target defense mechanisms, skills training may have favorable effects on defense function in BPD. Our findings contribute to an integrative understanding of mechanisms of change in BPD psychotherapy.


Clinical Nuclear Medicine | 2012

Longer intervals between hematopoietic stem cell transplantation and subsequent 90Y-ibritumomab radioimmunotherapy may correlate with better tolerance.

Franz Buchegger; John O. Prior; Gilles Allenbach; Sébastien Baechler; Marek Kosinski; Claudine Helg; Yves Chalandon; Osman Ratib; Angelika Bischof Delaloye; Nicolas Ketterer

Purpose This study aimed to evaluate the efficacy and toxicity of radioimmunotherapy (RIT) in recurrent lymphoma after hematopoietic stem cell transplantation (HSCT). Methods We reviewed 9 patients, 7 with follicular lymphoma (DLBCL), 1 with mantle cell lymphoma (MCL), and 1 with diffuse large B-cell lymphoma treated with 90Y-ibritumomab tiuxetan 6 to 140 months after HSCT. Patients underwent 111In-ibritumomab scintigraphy and were treated 1 week later with standard 14.8 MBq/kg (n = 4) or 11.1 MBq/kg (n = 4) 90Y-ibritumomab. One patient who had allo-HSCT had reduced activity (70%) treatment. Results Among the 7 FL patients, we observed complete response (CR) in 2 patients and partial response (PR) in 5 patients. One patient with CR relapsed after 15 months; the other persisted 43.5 months after RIT. Of 5 patients with PR, 3 relapsed between 13 and 17 months; 1 persisted until unrelated death at 11.5 months. The fifth patient with PR received adoptive immunotherapy and improved to metabolic (FDG-PET) CR that persists 45.5 and 41 months after 90Y-ibritumomab and immunotherapy, respectively. Patients with MCL and DLBCL progressed or experienced stabilization (5 months), respectively. Six patients had grade 1 to 3 bone marrow (BM) toxicity and recovered within 3 months. Three patients having 90Y-ibritumomab 6, 14, and 24 months after HSCT experienced grade 4 BM toxicity. One of them (RIT 24 months after HSCT) recovered after 3 months, another delayed after 9 months, and the third patient only partially recovered, eventually developed myelodysplasia, and was allografted. Conclusions Radioimmunotherapy after HSCT is an effective rescue therapy in FL. However, BM toxicity may be important; 3 of 8 patients treated with standard 90Y-ibritumomab activity experienced grade 4 BM toxicity, with incomplete recovery 3 months after RIT in 2 patients, both treated early (6 and 14 months) after HSCT.


European Journal of Nuclear Medicine and Molecular Imaging | 2012

Quantification of myocardial blood flow with 82Rb positron emission tomography: clinical validation with 15O-water

John O. Prior; Gilles Allenbach; Ines Valenta; Marek Kosinski; Cyrill Burger; Francis R. Verdun; Angelika Bischof Delaloye; Philipp A. Kaufmann

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Amin Dabiri

University of Lausanne

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