THUREAU Sébastien

Dr. THUREAU Sébastien

CENTRE HENRI BECQUEREL
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 August 2021 in Cancers
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THUREAU SébastienTHUREAU Sébastien
THUREAU Sébastien
NPNicolas Piton
Nicolas Piton
PGpierrick gouel
pierrick gouel
RMRomain Modzelewski
Romain Modzelewski
ADAntoine Dujon
Antoine Dujon
PVPierre Vera
Pierre Vera
Hypoxic areas are typically resistant to treatment. However, the fluorine-18-fluoroazomycin-arabinoside (FAZA) and fluorine 18 misonidazole (FMISO) tracers have never been compared in non small cell lung cancer (NSCLC). This study compares the capability of 18F-FAZA PET/CT with that of 18F-FMISO PET/CT for detecting hypoxic tumour regions in early and locally advanced NSCLC patients. We prospectively evaluated patients who underwent preoperative PET scans before surgery for localised NSCLC (i.e., fluorodeoxyglucose (FDG)-PET, FMISO-PET, and FAZA-PET). The PET data of the three tracers were compared with each other and then compared to immunohistochemical analysis (GLUT-1, CAIX, LDH-5, and HIF1-Alpha) after tumour resection. Overall, 19 patients with a mean age of 68.2 ± 8 years were included. There were 18 lesions with significant uptake (i.e., SUVmax >1.4) for the F-MISO and 17 for FAZA. The mean SUVmax was 3 (±1.4) with a mean volume of 25.8 cc (±25.8) for FMISO and 2.2 (±0.7) with a mean volume of 13.06 cc (±13.76) for FAZA. The SUVmax of F-MISO was greater than that of FAZA (p = 0.0003). The SUVmax of F-MISO shows a good correlation with that of FAZA at 0.86 (0.66–0.94). Immunohistochemical results are not correlated to hypoxia PET regardless of the staining. The two tracers show a good correlation with hypoxia, with FMISO being superior to FAZA. FMISO, therefore, remains the reference tracer for defining hypoxic volumes.

23 October 2018 in Radiation Oncology
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THUREAU SébastienTHUREAU Sébastien
THUREAU Sébastien
BDBernard Dubray
Bernard Dubray
RMRomain Modzelewski
Romain Modzelewski
Pierre BohnPierre Bohn
Pierre Bohn
SHSébastien Hapdey
Sébastien Hapdey
PVPierre Vera
Pierre Vera
Concomitant chemo-radiotherapy is the reference treatment for non-resectable locally-advanced Non-Small Cell Lung Cancer (NSCLC). Increasing radiotherapy total dose in the whole tumour volume has been shown to be deleterious. Functional imaging with positron emission tomography (PET/CT) offers the potential to identify smaller and biologically meaningful target volumes that could be irradiated with larger doses without compromising Organs At Risk (OAR) tolerance. This study investigated four scenarios, based on 18FDG and 18F-miso PET/CT, to delineate the target volumes and derive radiotherapy plans delivering up to 74Gy. Twenty-one NSCLC patients, selected from a prospective phase II trial, had 18FDG- and 18F-miso PET/CT before the start of radiotherapy and 18FDG PET/CT during the radiotherapy (42Gy). The plans were based planned on a standard plan delivering 66 Gy (plan 1) and on three different boost strategies to deliver 74Gy total dose in pre-treatment 18FDG hotspot (70% of SUVmax) (plan 2), pre-treatment 18F-miso target (SUVmax > 1.4) (plan 3) and per-treatment 18FDG residual (40% of SUVmax). (plan 4). The mean target volumes were 4.8 cc (± 1.1) for 18FDG hotspot, 38.9 cc (± 14.5) for 18F-miso and 36.0 cc (± 10.1) for per-treatment 18FDG. In standard plan (66 Gy), the mean dose covering 95% of the PTV (D95%) were 66.5 (± 0.33), 66.1 (± 0.32) and 66.1 (± 0.32) Gy for 18FDG hotspot, 18F-miso and per-treatment 18FDG. In scenario 2, the mean D95% was 72.5 (± 0.25) Gy in 18FDG hotspot versus 67.9 (± 0.49) and 67.9 Gy (± 0.52) in 18F-miso and per-treatment 18FDG, respectively. In scenario 3, the mean D95% was 72.2 (± 0.27) Gy to 18F-miso versus 70.4 (± 0.74) and 69.5Gy (± 0.74) for 18FDG hotspot and per-treatment 18FDG, respectively. In scenario 4, the mean D95% was 73.1 (± 0.3) Gy to 18FDG per-treatment versus 71.9 (± 0.61) and 69.8 (± 0.61) Gy for 18FDG hotspot and 18F-miso, respectively. The dose/volume constraints to OARs were matched in all scenarios. Escalated doses can be selectively planned in NSCLC target volumes delineated on 18FDG and 18F-miso PET/CT functional images. The most relevant strategy should be investigated in clinical trials. (RTEP5, NCT01576796 , registered 15 june 2012)

11 February 2021 in Cancers
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THUREAU SébastienTHUREAU Sébastien
THUREAU Sébastien
LLLucie Lebret
Lucie Lebret
JLJustine Lequesne
Justine Lequesne
MCMarine Cabourg
Marine Cabourg
SDSimon Dandoy
Simon Dandoy
FCFlorian Clatot
Florian Clatot
Highlights: Sarcopenia is frequent in patients treated with radiation therapy (RT) or radiochemotherapy (RTCT) for head and neck squamous cell carcinomas. Sarcopenia is associated with poor disease-free survival and overall survival outcomes. Sarcopenia is not associated with a higher rate of treatment-related toxicity. Background: Sarcopenia occurs frequently with the diagnosis of head and neck squamous cell carcinoma (HNSCC). We aimed to assess the impact of sarcopenia on survival among HNSCC patients treated with radiotherapy (RT) or radiochemotherapy (RTCT). Methods: Patients treated between 2014 and 2018 by RT or RTCT with curative intent were prospectively included (NCT02900963). Optimal nutritional support follow-up, including weekly consultation with a dietician and an oncologist and daily weight monitoring, was performed. Sarcopenia was determined by measuring the skeletal muscles at the L3 vertebra on the planning CT scan for radiotherapy. For each treatment group (RT or RTCT), we assessed the prognostic value of sarcopenia for disease-free survival (DFS) and overall survival (OS) and its impact on treatment-related toxicity. Results: Two hundred forty-three HNSCC patients were included: 116 were treated by RT and 127 were treated by RTCT. Before radiotherapy, eight (3.3%) patients were considered malnourished according to albumin, whereas 88 (36.7%) patients were sarcopenic. Overall, sarcopenia was associated with OS and DFS in a multivariate analysis (HR 1.9 [1.1–3.25] and 1.7 [1.06–2.71], respectively). It was similar for patients treated with RT (HR 2.49 [1.26–4.9] for DFS and 2.24 [1.03–4.86] for OS), whereas for patients treated with RTCT sarcopenia was significantly associated with OS and DFS in univariate analysis only. Sarcopenia was not related to higher treatment-related toxicity. Conclusions: Pretherapeutic sarcopenia remains frequent and predicts OS and DFS for non-frail patients treated with curative intent and adequate nutritional support.

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Juliette THARIATJuliette THARIAT
Juliette THARIAT
SVSamuel Valable
Samuel Valable
CLCarine Laurent
Carine Laurent
SHSiamak Haghdoost
Siamak Haghdoost
EPElodie Pérès
Elodie Pérès
François ChevalierFrançois Chevalier
François Chevalier
The resistance of cancer cells to radiotherapy is a major issue in the curative treatment of cancer patients. This resistance can be intrinsic or acquired after irradiation and has various definitions, depending on the endpoint that is chosen in assessing the response to radiation. This phenomenon might be strengthened by the radiosensitivity of surrounding healthy tissues. Sensitive organs near the tumor that is to be treated can be affected by direct irradiation or experience nontargeted reactions, leading to early or late effects that disrupt the quality of life of patients. For several decades, new modalities of irradiation that involve accelerated particles have been available, such as proton therapy and carbon therapy, raising the possibility of specifically targeting the tumor volume. The goal of this review is to examine the up-to-date radiobiological and clinical aspects of hadrontherapy, a discipline that is maturing, with promising applications. We first describe the physical and biological advantages of particles and their application in cancer treatment. The contribution of the microenvironment and surrounding healthy tissues to tumor radioresistance is then discussed, in relation to imaging and accurate visualization of potentially resistant hypoxic areas using dedicated markers, to identify patients and tumors that could benefit from hadrontherapy over conventional irradiation. Finally, we consider combined treatment strategies to improve the particle therapy of radioresistant cancers.

22 March 2022 in Entropy
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TBThibaud Brochet
Thibaud Brochet
Jérôme Lapuyade-LahorgueJérôme Lapuyade-Lahorgue
Jérôme Lapuyade-Lahorgue
AHAlexandre Huat
Alexandre Huat
THUREAU SébastienTHUREAU Sébastien
THUREAU Sébastien
DPDavid Pasquier
David Pasquier
Ruan SuRuan Su
Ruan Su
In this paper, we propose to quantitatively compare loss functions based on parameterized Tsallis–Havrda–Charvat entropy and classical Shannon entropy for the training of a deep network in the case of small datasets which are usually encountered in medical applications. Shannon cross-entropy is widely used as a loss function for most neural networks applied to the segmentation, classification and detection of images. Shannon entropy is a particular case of Tsallis–Havrda–Charvat entropy. In this work, we compare these two entropies through a medical application for predicting recurrence in patients with head–neck and lung cancers after treatment. Based on both CT images and patient information, a multitask deep neural network is proposed to perform a recurrence prediction task using cross-entropy as a loss function and an image reconstruction task. Tsallis–Havrda–Charvat cross-entropy is a parameterized cross-entropy with the parameter α. Shannon entropy is a particular case of Tsallis–Havrda–Charvat entropy for α=1. The influence of this parameter on the final prediction results is studied. In this paper, the experiments are conducted on two datasets including in total 580 patients, of whom 434 suffered from head–neck cancers and 146 from lung cancers. The results show that Tsallis–Havrda–Charvat entropy can achieve better performance in terms of prediction accuracy with some values of α.

22 May 2020 in Radiation Oncology
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RMRomain Mallet
Romain Mallet
RMRomain Modzelewski
Romain Modzelewski
JLJustine Lequesne
Justine Lequesne
SMSorina Mihailescu
Sorina Mihailescu
PDPierre Decazes
Pierre Decazes
THUREAU SébastienTHUREAU Sébastien
THUREAU Sébastien
Background: Sarcopenia is defined by a loss of skeletal muscle mass with or without loss of fat mass. Sarcopenia has been associated to reduced tolerance to treatment and worse prognosis in cancer patients, including patients undergoing surgery for limited oesophageal cancer. Concomitant chemo-radiotherapy is the standard treatment for locally-advanced tumour, not accessible to surgical resection. Using automated delineation of the skeletal muscle, we have investigated the prognostic value of sarcopenia in locally advanced oesophageal cancer (LAOC) patients treated by curative-intent chemo-radiotherapy. Methods: The clinical, nutritional, anthropometric, and functional-imaging (18FDG-PET/CT) data were collected in 97 patients treated between 2006 and 2012 in our institution. The skeletal muscle area was automatically delineated on cross-sectional CT images acquired at the 3rd. lumbar vertebra level and divided by the patient’s squared height (SML3/h2) to obtain the Skeletal Muscle Index (SMI). The primary endpoint was overall survival probability. Results: Seventy-six deaths were reported. The median survival time was 27 [95% Confidence Interval 23–40] months for the whole population. Univariate analyses (Cox Proportional Hazard Model) showed decreased survival probabilities in patients with reduced SMI, WHO > 0, Body Mass Index ≤21, and Nutritional Risk Index ≤97.5. Multivariate analyses showed that sarcopenia was the only significant prognostic factor (HR 2.32 [1.24–4.34], p = 0.008). Using Receiver Operating Characteristics curves, the Area Under the Curve (AUC) was 0.73 in males (p = 0.0002], the optimal threshold being 51.5 cm2/m2. In women, the AUC was 0.65 (p = 0.19). Conclusion: Sarcopenia is a powerful independent prognostic factor, associated with a rise of the overall mortality in patients treated exclusively by radiochemotherapy for a locally advanced oesophageal cancer. L3 CT images are easily gathered from 18FDG-PET/CT acquisitions.