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The aim of this multicentric study was to prospectively compare 68Ga-DOTANOC PET/CT versus somatostatin receptor scintigraphy (SRS) with SPECT/CT, combined with multiphasic CT scan and MRI in patients with grade 1 or 2 gastroenteropancreatic neuroendocrine tumors (GEP-NET). Patients with histologically proven grade 1 or 2 GEP-NET with suspicion of recurrence or progression, or with typical aspects of GEP-NET on morphological imaging, were explored with conventional imaging (CI): SRS with SPECT/CT, multiphasic CT scan and/or liver MRI followed by 68Ga-DOTANOC PET/CT. The gold standard was based on histology and imaging follow-up. The data of 105 patients (45 woman and 60 men; median age) were analyzed. 68Ga-DOTANOC PET/CT sensitivity was significantly higher than CI sensitivity in per-patient (98.9% vs. 88.6%, p = 0.016) and per-region (97.6% vs. 75.6%, p < 0.001) analyses, in the detection of the primary (97.9% vs. 78.7%; p = 0.016), peritoneal carcinomatosis (95% vs. 30%, p < 0.001), and bone metastases (100% vs. 33.3%, p = 0.041). 68Ga-DOTANOC PET/CT had an impact on the therapeutic management of 41.9% (44/105) patients compared to decisions based on CI explorations. Our data confirm the superiority of 68Ga-DOTANOC PET/CT over CI in the detection of peritoneal carcinomatosis and bone metastasis, as well as its strong therapeutic impact on the management of patients with grade 1-2 GEP-NETs.

International audience; In the management of prostate cancer in recent years, innovative therapies have appeared requiring precise and reliable disease detection. In 2021, new generation imaging (PET/CT, multiparametric MRI, PET/MRI) have their place at all stages of the prostate cancer natural history to help target the lesion(s) and guide therapy and improve the results obtained. PSMA PET/CT is currently the leader in this type of imaging with a complete offer during the disease: both from diagnosis, to recurrence or in the oligo-metastatic and metastatic stage resistant to castration with a pivotal role in the PSMA theranostic approach. However, multiparametric MRI also has many detection advantages when the prostate is left in place, which suggests the potential major benefit of hybrid PSMA PET/MRI imaging.

The formation of sensory organs is an important developmental and evolutionary question. In the context of regenerative medicine also, it is important to know as accurately as possible how sensory organs form. The formation of ears, eyes or nose stems presumably from tissue thickenings called placodes Graham and Shimeld (J Anat 222(1):32-40, 2013), Horie et al. (Nature 560:228-232, 2018) which become these organs after processes termed inductions. However, the origin of the placodes, the mechanism of induction and the overall face organization are not understood. Recently, it has been suggested that there is a physical principle to face organization. Indeed, it has been shown that there exists a pattern of rings and rays in the early blastula which defines the position of face landmarks, especially the ears and eyes Fleury et al. (Second order division in sectors as a prepattern for sensory organs in vertebrate development, 2021), Fleury and Abourachid (Eu Phys J E 45:31, 2022). Tensions in the sectors defined by the intersections of the said rings and rays create the actual face features. I report here that a similar situation exists for the nose. This explains the robustness of face formation in the chordates phylum. By studying nasal pit formation in the chicken embryo by time-lapse (T-L) video microscopy, I show that the nasal placode originates in a narrow sector deformed by tension forces following the biaxial pattern of rings and rays mentioned above. Cells align in the pattern and exert organized forces. Further contractions of the pattern contribute to inducing the nasal pit. The observation of the early pre-pattern of lines which locks the facial features explains readily a number of facts regarding sensory organs. Especially the existence of a lacrimal canal between the eye and the nose Lefevre and Freitag (Semin Ophthalmo l 27(5-6):175-86, 2012), or of a slit connecting the nose to the mouth, the correlation between nose, mouth and eye morphogenesis Dubourg et al. (J Rare Dis 2(8), 2007), the presence of shallow valleys on the nasal and optic vesicles, the medio-lateral asymmetry of nostrils with often a bent slit Liu et al. (PLoS ONE 12: e0181928, 2017), the uneven number of nostrils in many fish Cox (J R Soc Interf 5(23):575-593, 2008) and possibly the transition between agnatha and gnathostomes Gai and Zhu (Chinese Sci Bull 57(31), 2012): all appear under this light, geometrically straightforward. The nasal pit forms in a sector of tissue which was present on the blastodic (early embryonic stage), and which is projected onto the nasal vesicle during neurulation. The nasal pit forms along a hairpin of tissue. The top part of the hairpin forms the nares, and the bottom part a groove often visible in many animals.

Vaccination against coronavirus disease 2019 (COVID-19) is currently under worldwide deployment. The consequences of this vaccination can be seen in radiology and nuclear medicine explorations with visualization of axillary lymph nodes (LNs), as observed on ultrasonography, MRI, or 18F-FDG PET/CT.We aimed to evaluate on PET/CT the incidence of vaccine-related LNs and their characteristics after COVID-19 vaccination, using several radiopharmaceuticals different from 18F-FDG.Between February and July 2021, all consecutive patients undergoing a whole-body PET/CT for any indication using a different radiopharmaceutical from 18F-FDG were eligible for inclusion if they had received at least 1 dose of the COVID-19 vaccine. The radiopharmaceutical administered and vaccine type were recorded for each patient. The incidence of positive vaccine-related axillary and supraclavicular LNs on PET/CT was our primary finding, along with the nodes characteristics. Statistical analyses were performed for patients with prostate cancer (PCa) to determine certain interaction factors that were associated with the detection of vaccine-related LNs.Of the 226 patients in our cohort study, 120 patients underwent an 18F-fluorocholine PET/CT, 79 a 68Ga-PSMA-11 PET/CT, 6 an 18F-FDOPA PET/CT, and 21 a 68Ga-DOTATOC PET/CT. A total of 67.3% of patients (152/226) received BNT162b2mRNA (Pfizer-BioNTech), 26.5% (60/226) ChAdOx1-S (AstraZeneca), 4.9% (11/226) mRNA-1273 (Moderna), and 1.3% (3/226) Ad26.COV2.S (Janssen). The incidence of positive vaccine-related axillary and supraclavicular LNs was 42.5% (51/120 patients) on PET/CT using 18F-fluorocholine and 12.7% (10/79 patients) with 68Ga-PSMA-11. None of our patients undergoing 18F-FDOPA or 68Ga-DOTATOC PET/CT presented any vaccine-related lymphadenopathy. Vaccine-related LNs were statistically associated with the nature of the radiopharmaceutical (P10-4), with the number of vaccine doses received (P = 0.041), with a short delay between vaccination and PET/CT realization (P10-5), and with a higher prostate-specific antigen level for patients with PCa (P = 0.032), but not with age or vaccine type. The vaccine-related nodes appeared in 85% of the cases, in the 30 days after vaccine injection, were limited in size and uptake, and were most often limited to the axilla level 1 area.Detecting positive LNs after COVID-19 vaccination is not an exclusive 18F-FDG PET/CT pattern but is common on 18F-fluorocholine and possible on 68Ga-PSMA-11 PET/CT. Confronting PET/CT findings with clinical data (such as date and site of injection) seems essential in the current pandemic context, just as it does for the radiopharmaceuticals used in PCa to avoid PET/CT misinterpretation and incorrect patient treatment. For 18F-FDOPA or 68Ga-DOTATOC PET/CT, this seems to have a lesser impact.

A Correction to this paper has been published: 10.1140/epje/s10189-022-00184-4

Digestive peristalsis generates many artifacts that limit the abdominal and pelvic MRI interpretation. Apart from the hypoglycemia treatment in patients with diabetes, glucagon analog is also indicated for the digestive peristalsis reduction to reduce MRI artifacts. However, its use in PET/MRI is not described, given the risk of interaction with the metabolism of FDG. To assess the importance of this interaction on the FDG PET images, we report FDG PET/MRI images obtained with and without glucagon analog injection.

In this issue of the Journal, Dr. Risch (Am J Epidemiol. 2020;189(11):1218–1226) posits that the use of a combination of hydroxychloroquine and azithromycin as an outpatient treatment for high-risk patients with coronavirus 19 should be increased as a way to help curtail the ongoing pandemic. However, a calculation error occurred in the original article, and new data about the studies cited have come to light. Peculiarities in the methods of data collection and reporting in those original sources must be considered when evaluating the evidence for or against hydroxychloroquine and azithromycin bitherapy.

Background The vaccination immune response may induce false-positive 18F-FDG PET/CT uptake. Case presentation An extended supraclavicular lymph nodal activation after coronavirus disease 2019 (COVID-19) vaccination revealed on 18F-FDG PET/CT mimics a Virchow nodule in a patient with medical history of well-differentiated appendicular adenocarcinoma. Conclusion This case highlights a nodal activation beyond axillary area and the importance of documenting vaccination history at the time of scanning to avoid false-positive results.

PURPOSE The aim of this study was to compare retrospectively 18F-DOPA PET/CT versus 68Ga-DOTANOC PET/CT in a group of patients affected by midgut NET. PATIENTS AND METHODS Patients with histologically proven grade 1 or grade 2 midgut NET were explored after injection of 150 MBq of 68Ga-DOTANOC and 210 MBq of 18F-DOPA. The PET/CTs were analyzed visually and semiquantitatively at the patient level, regional level (7 defined regions), and lesion level (maximum of 5 lesions/organ). The criterion standard was determined on the basis of histology and imaging follow-up. RESULTS Thirty patients (17 males and 13 females; median age, 63.5 years [37-82 years]) were included. Both PET/CTs were negative in 3 patients and positive in 25 patients. PET/CTs were discordant in 2 patients, with 18F-DOPA positive and 68Ga-DOTANOC negative. 18F-DOPA PET/CT detected more involved regions and more metastatic lesions than 68Ga-DOTANOC PET/CT in 6 (20%) and 10 (33.3%) patients, respectively. Of the 81 confirmed affected regions, 77 (95%) were detected by 18F-DOPA PET/CT and 71 (87.7%) by 68Ga-DOTANOC PET/CT (P < 0.0001). 18F-DOPA PET/CT detected significantly more lesions (211/221) than 68Ga-DOTANOC PET/CT (195/221), corresponding to a sensitivity of 95.5% and 88.2%, respectively (P < 0.0001). Tumor-to-background ratios were more favorable in liver for 18F-DOPA than for 68Ga-DOTANOC. Interestingly, a correlation was found between 18F-DOPA SUVmax and tumor burden and especially with the number of regions involved by the disease (P = 0.019). CONCLUSIONS 18F-DOPA PET/CT is superior to 68Ga-DOTANOC PET/CT for the detection of lesions, and when available, this tracer may be recommended as the first-line examination for an accurate staging of midgut NET.

We present in vivo observations of chicken embryo development which show that the early chicken embryo presents a principal structure made out of concentric rings and a secondary structure composed of radial sectors. During development, physical forces deform the main rings into axially directed, antero-posterior tubes, while the sectors roll up to form cylinders that are perpendicular to the antero-posterior axis. As a consequence, the basic structure of the chicken embryo is a series of encased antero-posterior tubes (gut, neural tube, body envelope, amnion, chorion) decorated with smaller orifices (ear duct, eye stalk, nasal duct, gills, mouth) forming at right angles to the main body axis. We argue that the second-order divisions reflect the early pattern of cell cleavage, and that the transformation of radial and orthoradial lines into a body with sensory organs is a generic biophysical mechanism more general than the chicken embryo.

International audience; Radiopharmaceutical extravasation is a known nuclear medicine adverse effect, mostly with no complication in case of diagnostic radiopharmaceutical. However, a therapeutic radiopharmaceutical extravasation may have clinical consequences and must be treated quickly and effectively. We report here a case of 177Lu-DOTA0-Tyr3-octreotate extravasation.

Abstract We propose a simple biaxial tensional model which is able to reproduce at a qualitative level several aspects of early stages of vertebrate morphogenesis. The model is based on subsequent excitable contractions of an orthoradial and periclinal (radial) set of contracting lines, which generate first the basic embryonic pattern (a motile tube), and second the lateral orifices such as ears, eyes, mouth, gills, etc. An important aspect of the model is the self-arresting character of the process, akin to wound healing. At later stages, the biaxial lines may also work in extension, and this generates a developmental feedback which is quadratic with respect to curvature. Graphic abstract

e13057 Background: In metastatic breast cancer (MBC), treatment response is often assessed with FDG PET per PERCIST which evaluates changes in SULpeak of the single hottest tumor lesion identified on the baseline and follow-up images. PERCIST therefore does not consider tumor heterogeneity. This work aims to compare responses determined with the automatic segmentation of all lesions to response determined manually per PERCIST. Methods: 10 MBC patients (61±14 y/o) undergoing either chemo- or hormonotherapy were randomly selected from the prospective EPICURE study (NCT03958136). A baseline and two follow-up FDG PET were acquired at pre-, early- (1 month) and mid-treatment times for each patient. All metastatic lesions on all images were manually segmented by experts. Using the Advanced Normalization Tools (ANTs) image registration method, we wrapped baseline lesion segmentations to automatically obtain the follow-up ones. These registered segmentations were compared to the ones done manually using standard biomarkers: SULpeak, lesion size and Total Lesion Glycolysis (TLG). Differences between baseline and follow-up images were visually represented by coloring the follow-up segmentations: in green for responsive lesions (decreasing SULpeak) and in red for progressive ones (increasing SULpeak). Two expert physicians were then asked to evaluate treatment response while seeing these colored segmentations. They assessed the FDG PET images in pairs, evaluating for each patient the baseline and one of the corresponding follow-ups in a blinded manner: either the early- or the mid-treatment follow-up. Evaluations were then compared: i) early- vs mid-treatment response and ii) follow-up response vs patient’s clinical outcome. Results: Biomarkers extracted from the registered segmentations were similar to the ones extracted from the manual segmentations, with a Lin correlation coefficient of 0.92, 0.87 and 0.95 for the SULpeak, lesion size and TLG respectively. These findings were obtained within ̃10min, whereas the manual segmentation of the three PET images for any given patient took ̃1h. With the use of colored segmentations, early follow-up evaluations were predictive of mid-treatment response in 65% of the cases. The blinded physicians agreed with the clinical outcomes 85% and 95% of the time for the early- and mid-treatment images respectively. Conclusions: With segmentations automatically derived from ANTs registration, we managed to extract biomarkers that are comparable to the ones obtained with manual segmentations; both segmentations carried similar information. ANTs fast registration and biomarkers computation can make it a useful tool in clinical routine. In addition, lesion coloring helped evaluate treatment response and early-treatment follow-up images were shown to be predictive of mid-treatment response. Clinical trial information: NCT03958136.

e12557 Background: Triple-negative breast cancer (TNBC) tends to exhibit aggressive behavior lacking from targeted therapies. Tumor-associated-macrophages (TAMs as M2 and M1 macrophages) are interest targets in TNBC to approach the tumor patient immunity. The mitochondrial translocator protein (TSPO), a sensitive marker for macrophages, could be interesting for TNBC micro-environment stratification. We performed a multicenter imaging pilot study (NCT04320030) using non-invasive [18F]DPA-714 (DPA), a TSPO PET radioligand, aiming at assessing immunity to define the immunotherapy possibilities in TNBC patients. Methods: All patients underwent TSPO genotyping (LAB: Low Affinity Binder, MAB: Mixed and HAB: High), [18F]FDG (FDG) and DPA PET-CT, macrophages immunochemistry and in vitro TSPO autoradiography using both tritiated PK11195 (PK) and DPA. Thorax PET-CT was acquired just after injection (DPA1) to 30 min, then from 45 min (DPA2) to 60 min, followed by a whole body PET-CT. Groups of interest (Macrophages immunochemistry and Genotype) were compared using Kruskal-Wallis test. Correlation between continuous parameters were determined using Spearman’s Rho. Results: A total of 13 TNBC patients were included. No adverse events occurred after DPA injection. For TSPO genotyping, 2/13 (15.5%) patients were LAB, 6/13 (46%) MAB and 5/13 (38.5%) HAB. All of them showed FDG and DPA uptake regardless of the patient's genotype without significant difference between the 3 groups. The DPA kinetics showed a tracer accumulation between DPA1 and DPA2, whatever patient genotypes, observed on SUVmax (p = 0.0015), SUVmean (p = 0.0015) and TL-DPA (p = 0.0024). A correlation between FDG and DPA1 either DPA2 tumor volume was shown, respectively (p = 0.0252 and 0.0067) as well as between the TLG (FDG) and the TL-DPA1 (p = 0.0346) regardless of the patient's genotype. Macrophages immunochemistry showed a tendency difference for M2 percentage (p = 0.09) between the 3 genotypes groups. In vitro binding ratio (PK/DPA), measured for both radioligands, on adjacent tumor slices, was 1.77 (1.35-2.21). A difference in this binding ratio was observed between MAB and HAB (Mean 1.68±0.36) compared to LAB 3.04±0.23 (p = 0.0367), suggesting that DPA binding is sensitive to TSPO genotype, unlike PK binding. Conclusions: Despite the limited population, all TNBC tumor patients were DPA positive with an accumulation over time. The total glycolysis and total DPA uptake in the tumor were correlated, which may link tumor aggressiveness and DPA uptake. These data were confirmed by a better sensitivity for HAB and MAB vs LAB. DPA seemed to be a promising tracer to explore non-invasively TNBC patient’s immunity. Clinical trial information: NCT04320030.

International audience; Cross-modality synthesis represent nowadays a promising application in medical image processing to manage the problem of paired data scarcity. In this work we designed and trained a CycleGAN model to generate PET/CT data from 2D slices collected from the liver body region of twelve patients. The results obtained from the six test patients show how our model can outperform baseline CycleGAN framework and effectively be used for synthesizing artificial images to be used for data augmentation or dataset completion.

Purpose To assess the rate and pattern of incidental interstitial lung abnormalities suggestive of COVID-19 on 18F-FDG PET/CT in asymptomatic cancer patients during the period of active COVID-19 circulation between March and April 2020 in a geographic area of low prevalence of the virus. Methods 1396 18F-FDG PET/CT performed between January 1, 2020, and February 21, 2020, and between March 16, 2020, and April 17, 2020 for routine oncological indication were retrospectively analyzed. No patients had symptoms suggestive of COVID-19 at the time of the 18F-FDG PET/CT. Incidental interstitial pneumonias suggestive of COVID-19 were identified, and the 18F-FDG PET/CT patterns were described. We compared the incidence of these lesions in the pre-COVID and pandemic phases. Results We observed a 1.6% increase in interstitial lung abnormalities during the period of COVID-19 circulation. All had

We present in vivo observations of chicken embryo development which show that the early chicken embryo presents a principal structure made out of concentric rings and a secondary structure composed of radial sectors. During development, physical forces deform the main rings into axially directed, antero-posterior tubes, while the sectors roll up to form cylinders that are perpendicular to the antero-posterior axis. As a consequence, the basic structure of the chicken embryo is a series of encased antero-posterior tubes (gut, neural tube, body envelope, amnion, chorion) decorated with smaller orifices (ear duct, eye stalk, nasal duct, gills, mouth) forming at right angles to the main body axis. We argue that the second-order divisions reflect the early pattern of cell cleavage, and that the transformation of radial and orthoradial lines into a body with sensory organs is a generic biophysical mechanism more general than the chicken embryo.

International audience; Prostate cancer (PCa) pelvic radiotherapy fields are defined by guidelines that do not consider individual variations in lymphatic drainage. We examined the feasibility of personalized sentinel lymph node (SLN)-based pelvic irradiation in PCa. Among a SLN study of 202 patients, we retrospectively selected 57 patients with a high risk of lymph node involvement. Each single SLN clinical target volume (CTV) was individually segmented and pelvic CTVs were contoured according to Radiation Therapy Oncology Group (RTOG) guidelines. We simulated a radiotherapy plan delivering 46 Gy and calculated the dose received by each SLN. Among a total of 332 abdominal SLNs, 305 pelvic SLNs (beyond the aortic bifurcation) were contoured (mean 5.4/patient). Based on standard guidelines, CTV missed 67 SLNs (22%), mostly at the common iliac level (40 SLNs). The mean distance between iliac vessels and the SLN was 11mm, and despite a 15mm margin around the iliac vessels, 9% of SLNs were not encompassed by the CTV. Moreover, 42 SLNs (63%) did not receive 95% of the prescribed dose. Despite a consensus on contouring guidelines, a significant proportion of SLNs were not included in the pelvic CTV and did not receive the prescribed dose. A tailored approach based on individual SLN detection would avoid underdosing pelvic lymph nodes that potentially contain tumor cells.

Les etudes sur la TEP/TDM aux analogues de la somatostatine radiomarques au 68Ga chez les patients atteints de TNE sont pour la plupart retrospectives ou heterogenes en termes de recrutement. Cette etude multicentrique a analyse prospectivement l’interet de la TEP/TDM-68Ga-DOTANOC comparativement au bilan conventionnel optimise (BCO: scintigraphie a l’Octreoscan® corps entier avec TEMP/TDM, scanner thoraco-abdomino-pelvien multiphase et lorsque necessaire IRM hepatique), chez les patients presentant une TNE-GEP grade 1–2. Le gold standard incluait l’histologie, les donnees de l’ensemble des imageries et du suivi a 12 mois. Les donnees de 105 patients ont ete analysees : 45 femmes, 60 hommes, d’âge median: 62,8 ans, explores pour bilan initial (n = 48), suspicion de rechute/progression (n = 31), suivi (n = 15) ou caracterisation d’une lesion suspecte de TNE en imagerie conventionnelle (n = 11). Les primitifs etaient majoritairement pancreatiques (42,9 %) puis greliques (30,5 %), et les tumeurs de grade 2 dans 52,0 % des cas. La sensibilite de la TEP/TDM-68Ga-DOTANOC etait significativement superieure a celle du BCO dans l’analyse par patient (97,7 % vs 88,6 %, p = 0,043), par region (96,9 % vs 75,6 %, p Cette etude confirme la superiorite de la TEP/TDM-68Ga-DOTANOC par rapport au BCO pour le bilan lesionnel des TNE-GEP grade 1–2, notamment dans des localisations de petite taille ou d’analyse difficile comme la carcinose peritoneale.

I present a simple model of vertebrate embryogenesis, coupling cell division, differentiation, and morphogenesis. The model relies on a gradient of cell cycle period, in a flat shell of tissue. When the cell cycle period varies linearly between two points, a cascade of cell division occurs in the tissue, which generates a staircase of cell sizes (the Angel's staircase). The variation in cell size is associated to a stepwise variation of mechanical properties, which induces a deterministic pattern of folds. The folded shell is recognized as an animal.

Resume Le curage cervical realise lors des recidives ganglionnaires de cancers ORL apres radiotherapie initiale presente une importante morbidite. La TEP/TDM 18 FDG semble interessante dans cette indication, mais merite une standardisation des interpretations. Notre objectif etait d’elaborer une methode d’interpretation des TEP 18 FDG realisees dans les suspicions de recidive loco-regionale des cancers ORL. Vingt-sept patients suivis pour cancer ORL traites initialement par radiotherapie ± chimiotherapie, suspects de recidive ganglionnaire, ont ete inclus retrospectivement. Une TEP 18 FDG a ete realisee avant curage ganglionnaire et obtention d’une preuve histologique. Les compte rendus initiaux, une echelle visuelle binaire, une echelle visuelle 5 grades « Deauville like » et des index semi-quantitatifs ont ete analyses par 2 relecteurs independants. Dix-neuf patients (70 %) etaient en recidive ganglionnaire sur l’histologie. L’analyse des compte rendus TEP retrouvait 6 faux positifs (FP), 2 vrais negatifs (VN) et 19 vrais positifs (VP) soit des sensibilite (se), specificite (sp), valeurs predictives positives (VPP) et negatives (VPN) respectives de 100 %, 25 %, 76 % et 100 %. L’echelle binaire a reclasse 1/6 FP. Avec l’echelle « Deauville like », 4/6 FP ont ete reclasses par le premier relecteur ( p p 18 FDG lors des suspicions de recidive ganglionnaire de cancer ORL.

Resume Le cancer de la prostate metastatique n’est que sensible transitoirement a la chimiotherapie actuelle. La therapie par des anticorps monoclonaux radiomarques qui cible l’antigene membranaire specifique de la prostate (PSMA) est prometteuse et constitue un domaine de recherche. Le J591 est un anticorps monoclonal IgG de-immunise, developpe pour cibler le domaine extracellulaire du PSMA. Des etudes cliniques en phase I/II utilisant le J591 radiomarque ont demontre leur efficacite dans le ciblage des cellules tumorales et la diminution des taux de PSA. Le J591 radiomarque est bien tolere, non immunogene et peut etre administre en doses fractionnees. La toxicite limitant la dose est une myelosuppression reversible. Les etudes actuelles comprennent des approches visant a initier de nouvelles strategies d’association pour ameliorer le succes de la radioimmunotherapie anti-PSMA.

BACKGROUND In this prospective study (NCT03443609), we investigated the impact of 68Ga-PSMA-11 PET-CT on the treatment plan and therapeutic response obtained for patients with prostate cancer (PCa) presenting a recurrence with a low rising PSA. METHODS One hundred thirty hormone-naive (PSA

International audience; Current knowledge on limbs development lacks a physical description of the forces leading to formation of the limbs precursors or "buds". Earlier stages of development are driven by large scale morphogenetic movements, such as dipolar vortical flows and mechanical buckling, pulled by rings of cells. It is a natural hypothesis that similar phenomena occur during limb formation. However it is difficult to experiment on the developmental forces, in such a complex dynamic system. Here, we report a physical study of hindlimb bud formation in the chicken embryo. We use electrical stimulation to enhance the physical forces present in the tissue, prior to limb bud formation. By triggering the physical forces in a rapid and amplified pattern, we reveal the mechanism of formation of the hindlimbs : the early presumptive embryonic territory is composed of a set of rings encased like russian-dolls. Each ring constricts in an excitable pattern of force, and the limb buds are generated by folding at a pre-existing boundary between two rings, forming the dorsal and ventral ectoderms. The amniotic sac buckles at another boundary. Physiologically, the actuator of the excitable force is the tail bud pushing posteriorly along the median axis. The developmental dynamics suggests how animals may evolve by modification of the magnitude of these forces, within a common broken symmetry. On a practical level, localized electrical stimulation of morphogenetic forces opens the way to in vivo electrical engineering of tissues.

The aim of this retrospective multicentric study was to develop and evaluate a prognostic

In this prospective study (NCT03443609), we investigated the impact of 68Ga-PSMA-11 PET-CT on the treatment plan and therapeutic response obtained for patients with prostate cancer (PCa) presenting a recurrence with a low rising PSA.One hundred thirty hormone-naive (PSA 1.5 ng/mL) patients were enrolled. All patients received radical treatment. PET images were recorded 1 and 2 hours after injection of tracer and interpreted by two independent nuclear physicians. Six months after treatment ended, a PSA assay was requested to evaluate the therapeutic efficacy of the treatment based on PSMA results.Data analysis for the first 52 included patients has been completed. 68Ga-PSMA-11-positive lesions were detected in 38/52 (73.1%) patients. Ninety-four lesions were detected as follows, 53/94 in lymph nodes (56.4%), 25/94 in bone (26.6%), and 12/94 into the prostate bed (12.7%). Detection rates were 58%, 81%, and 82% for serum PSA levels lower than 0.25 ng/mL, between 0.25 to ≤ 0.69 ng/mL and 0.70 ng/mL, respectively. As a result of the PSMA PET-CT, therapeutic management changed in 38/52 patients (73.1%). Patients had undetectable serum PSA levels after treatment guided by 68Ga-PSMA-11 PET-CT results in 10/52 (19.2%) cases and with a PSA decrease of over 60% in 18/52 (34.6%) patients.Whilst our patient population presented a very low PSA level, preliminary results of the 68Ga-PSMA PET-CT study showed recurrence localization in more than half of the patients and this had a major clinical impact, as it resulted in treatment change in more than half of the patients and a significant decrease in PSA levels in a third of patients.

International audience; BACKGROUND:In this retrospective study, we investigated the impact of 68 Ga-PSMA-11 PET-CT (PSMA PET-CT) upon the treatment plan and therapeutic response obtained for Prostate Cancer (PCa) patients presenting an occult biochemical recurrence.METHODS:Forty-two patients with previously negative or doubtful 18F-Choline (FCH) were enrolled. PET images were recorded 1 h after injection of tracer. Only a few months after treatment ended, a PSA assay was requested to evaluate the therapeutic efficacy of the treatment based on PSMA results.RESULTS:PSMA-positive lesions were detected in 34/42 (80.9%) patients. Detection rates were 85.7% and 89.3% for serum PSA levels lower than 2 ng/mL, and >2 ng/mL, respectively. One hundred seventy-three lesions were detected: 132/173 in lymph nodes (76.3%), 22/173 as metastatic sites (bone or lung) (12.7%), and 19/173 in the prostate bed (10.9%). As a result of the PSMA PET-CT, therapeutic management changed in 31/42 patients (73.8%). With a follow-up of 4.9 ± 2.27 months, 32/42 (76.2%) PSA assays after treatment guided by PSMA PET-CT were collected. For 37.5% (12/32) of patients, the serum PSA level was lower than 0.2 ng/mL and a PSA decrease of over 50% in 8 (25.0%) other patients were obtained.CONCLUSION:Performing a PSMA PET-CT when FCH PET-CT was doubtful or negative allows the recurrence localization in more 80% of patients and this had a major clinical impact, as it resulted in treatment change in more than 70% of patients as well as a significant decrease in PSA levels in more than 60% of them.

The paper is concerned with the characterization of jet noise sources and jet–airfoil interaction sources by using microphone array data. The measurements were carried-out in the anechoic open test section wind tunnel of Onera, Cepra19. The microphone array technique relies on the convected, Lighthill׳s and Ffowcs-Williams and Hawkings׳ acoustic analogy equation. The cross-spectrum of the source term of the analogy equation is sought. It is defined as the optimal solution to a minimal error equation using the measured microphone cross-spectra as reference. This inverse problem is ill-posed yet. A penalty term based on a localization operator is therefore added to improve the recovery of jet noise sources. The analysis of isolated jet noise data in subsonic regime shows the contribution of the conventional mixing noise source in the low frequency range, as expected, and of uniformly distributed, uncorrelated noise sources in the jet flow at higher frequencies. In underexpanded supersonic regime, a shock-associated noise source is clearly identified, too. An additional source is detected in the vicinity of the nozzle exit both in supersonic and subsonic regimes. In the presence of the airfoil, the distribution of the noise sources is deeply modified. In particular, a strong noise source is localized on the flap. For high Strouhal numbers, higher than about 2 (based on the jet mixing velocity and diameter), a significant contribution from the shear-layer near the flap is observed, too. Indications of acoustic reflections on the airfoil are also discerned.

Acoustic liners for aeronautics have mostly a Helmholtz resonator behavior provided by perforated sheets backed by honeycombs. They may be used at the surface of a landing gear door to reduce the noise generated at landing. However, their acoustic absorption ability is naturally limited to medium and high frequencies due to thickness constraints. The LEONAR concept (Long Elastic Open Neck Acoustic Resonator) is proposed to overcome the problem of available space in case of “low frequency” range. The design consists in a meta-surface in which a perforated plate is coupled with tubes of variable lengths. This meta-surface covers a back cavity with limited volume and generate a significant shift in the frequency range of absorption, towards lower frequencies. First, an optimization problem is carried out to obtain the LEONAR meta-surface design that allows a maximal absorption coefficient between 400 and 1000 Hz, for a low thickness and a grazing flow up to Mach 0.2. Then the effect of impedance surface is checked by simulation of the radiated pressure field produced by a monopole source in presence of a landing gear door and compared with wind tunnel tests. The measurements showed significant attenuation within the prescribed range (D(OASPL) up to 1.5dBA).

Introduction Le 64Cu-ATSM est un medicament radiopharmaceutique (MRP) initialement developpe comme traceur TEP ciblant l’hypoxie tumorale, maintenant mieux defini comme traceur du stress oxydatif, etat lie a l’agressivite tumorale et les resistances au traitement. Notre essai clinique a pour but d’etudier, avec l’inclusion de 70 patients, la TEP-TDM au 64Cu-ATSM dans la prediction de la reponse au traitement neo-adjuvant dans le cancer du rectum. Methode Le 64Cu-ATSM est un complexe lipophile qui diffuse librement dans les membranes cellulaires. Sous l’effet du potentiel super-reducteur intracellulaire, le 64Cu est libere et s’accumule dans les cellules en etat de stress oxydatif. Le 64Cu est un emetteur B+ d’energie moy 278,2 keV, avec une T1/2 = 12,7 h. Etre autorise a utiliser ce MRP dans un essai clinique a necessite la redaction collaborative et multidisciplinaire d’un dossier du medicament experimental avec les equipes d’ARRONAX, cyclotron producteur de 64Cu, la Radiopharmacie de la PUI du CHU Nantes implantee dans ARRONAX et habilitee a delivrer les MRP en condition GMP et la Medecine Nucleaire de l’Institut de Cancerologie de l’Ouest. L’objectif principal est d’evaluer l’intensite de la fixation tumorale precoce du 64Cu-ATSM comme facteur predictif de la reponse histologique (estimee par un score de Rodel 3 ou 4) au traitement neo-adjuvant par radiochimiotherapie, dans le cancer du rectum localement avance. Les objectifs secondaires sont : etudier les intensites de fixation au temps tardif, les comparer avec la TEP-TDM au 18FDG, evaluer la correlation entre le 64Cu-ATSM et les marqueurs histopathologiques du stress oxydatif, evaluer la survie sans progression et mener une etude dosimetrique. Le bilan d’inclusion comprend une TEP-TDM au 18FDG, un TDM thoraco-abdomino-pelvienne et une IRM pelvienne. Pour la TEP-TDM au 64Cu-ATSM, 2 acquisitions sont realisees, centrees sur abdomen - pelvis, 1 h et 24 h apres injection. L’imagerie apres la fin de la radio-chimiotherapie comprend une TEP-TDM au 18FDG et une IRM pelvienne, avant chirurgie. Conclusion Cet essai clinique de phase II multicentrique, illustrant le developpement de MRP innovants, a ete autorise et a debute avec l’inclusion de 2 premiers patients, sans evenement indesirable signale. Les contraintes reglementaires liees au developpement de nouveaux MRP s’additionnent a celles de la recherche clinique, indispensables pour la securite, mais necessitant une approche interdisciplinaire.

Understanding vascular development in vertebrates is an important scientific endeavor. Normal vasculatures generally start off as a disorganized capillary lattice which progressively matures into a well-organized vascular loop comprising a hierarchy of arteries and veins. One striking feature of vascular development is the interlacing of arteries and veins. How arteries and veins manage to avoid themselves and interlace with such a perfect architecture is not understood. Here we present a detailed view of the development of the vasculature in the chorioallantoic membrane of the chicken embryo. We find that the origin of arteriovenous interlacing lies in the presence of an increased hemodynamic resistance at the distal part of the arteries due to vascular flattening onto the ectodermal surface. This reduces the vascular conductance distally, thus repelling veins away. In more proximal parts, vessels round off into cylinders and the increased flow attracts veins., Sophie Richard et al. present a detailed study of the development of the vasculature in the chicken embryo chorioallantoic membrane. They find that the interlacing of arteries and veins arises due to differential hemodynamic resistance acting on the distal and proximal ends of the arteries causing veins to be alternately repelled or attracted.

// Vincent Fleury 1 , Ludovic Ferrer 2, 4 , Mathilde Colombie 1 , Daniela Rusu 1 , Maelle Le Thiec 1 , Francoise Kraeber-Bodere 1, 2 , Loic Campion 2, 3 and Caroline Rousseau 1, 2 1 Nuclear Medicine Unit, ICO Cancer Center, Saint Herblain, France 2 Nantes-Angers Cancer Research Center, INSERM U892, CNRS UMR 6299, University of Nantes, Nantes, France 3 Biometrics Unit, ICO Gauducheau Cancer Center, Saint Herblain, France 4 Medical Physics Unit, ICO Cancer Center, Saint Herblain, France Correspondence to: Vincent Fleury, email: vfleury245@gmail.com Keywords: SPECT/CT; bone scan; bone metastases; bone index; prostate cancer Received: March 29, 2018 Accepted: July 18, 2018 Published: August 03, 2018 ABSTRACT Propose: The aim of our study was to evaluate the potential benefit of a systematic trunk SPECT/CT associated with a Planar Bone Scan (PBS) in breast cancer (BC) and prostate cancer (PCa) patients at initial staging or recurrence. Results: In 328 patients, sensitivities and specificities were between 74.4–93% and 78.8–97.5% for PBS and 97.7–100% and 96.8–98.6% for SPECT/CT respectively. PBS was considered equivocal for 67 compared to only 6 patients for trunk SPECT/CT. Regardless of “optimistic” or “pessimistic” analysis of equivocal trunk SPECT/CT lesions, the trunk SPECT/CT was almost perfect, allowing to rely on this result for excluding metastatic disease which was corroborated by ROC curve analysis. The trunk SPECT/CT allowed downstaging for 62 patients (19%) and upstaging for 11 patients. Materials and Methods: PBS and a trunk SPECT/CT were systematically performed in all patients. Independent review of PBS and trunk SPECT/CT was performed for each patient and an abnormality interpretative score (Sc) with 3 levels was built: Sc 1: metastatic or probably metastatic pattern, Sc 2: equivocal pattern, Sc 3: benign or probably benign pattern or no abnormality. The bone pattern status was defined by at least 1 year follow-up. The clinical impact was evaluated in terms of down and upstaging in patient analysis. Conclusions: Trunk SPECT/CT improves the performance of PBS in BC and PCa assessments and results in improvements in both the detection performance of bone metastases as well as a better characterization of equivocal lesions.

Within the LINFaN research project, Airbus and Rolls-Royce have jointly investigated the acoustic impact of supersonic jet noise on the fuselage of an Airbus A340 equipped with Rolls-Royce Trent 500 engines in cruise conditions. The main results are presented in this paper. The influence of chevron fan nozzles designed to reduce cruise jet noise on the rear fuselage is investigated. The characterization of both the acoustic field and the aerodynamic flow is carried out. The acoustic data are obtained from a microphone array on the rear fuselage. After specific data de-noising, the acoustic spectra radiated on the fuselage by only the right inner engine are estimated. Beamforming acoustic maps are also computed to localize the jet noise sources. Besides, the supersonic jet flows are characterized by RANS CFD approach. For the baseline round nozzle, the acoustic results show the presence of two distinct broadband shock-associated noise contributions on the fuselage. The first pattern is observed in the far aft section of the fuselage for Strouhal numbers based on the jet mixing diameter and velocity between St = 4 and 6. The other pattern, around St = 1, radiates preferably forward. In addition, the high frequency source is located between 4 and 5 mixed jet diameters past the secondary nozzle exhaust plane, while the low frequency source is located farther downstream between 7 and 8 mixed jet diameters. Shock-associated noise is usually associated with the interaction between shock cells and turbulent shear-layers. We postulate that the high-frequency noise component results from the interaction between the shock-cells in the secondary flow and the inner shear-layer, while the low-frequency component is due to the interaction between shock cells and the outer shear-layer. This interpretation is consistent with two observations. The first observation is a strong modification of the measured high frequency noise when the engine is pushed to high power. At this regime shock cells are present in the primary flow and the inner shear layer interacts with two supersonic flows, hence modifying emitted noise. The second observation is the reduction of low-and high-frequency noise by the introduction of chevron fan nozzles. The flow field results confirm the strong impact of chevrons on the structure of the shock cells in the fan stream: they are consistent with the experimental observations of the characteristic shock noise frequencies. For the Trent 500 engine, appropriate immersive fan chevrons may bring noise reductions by as much as 6dB SPL integrated over a relevant Strouhal number range [0.7; 2]. However, the reduction level due to the chevrons varies with the engine operating conditions. A given chevron nozzle may be found more efficient at reducing noise levels at low engine operating regime than at high regime.

Introduction et but de l’etude L’objectif de cette etude etait de developper et d’evaluer une signature radiomique en utilisant l’imagerie tomographique par emission de positons (TEP/TDM) chez des patients atteints d’un cancer du poumon non a petites cellules traites par irradiation stereotaxique. Materiel et methodes Il s’agit d’une etude retrospective multicentrique portant sur 87 patients atteints d’un atteints d’un cancer du poumon non a petites cellules de stade T1-T2 traite dans quatre centres du Grand Ouest. Les patients des trois premiers centres (n = 27, 29 et 8) constituaient le groupe d’apprentissage, et ceux du quatrieme (n = 23) le groupe de validation. Le critere d’evaluation principal etait le controle local. En tout, 184 parametres radiomiques ont ete extraits (92 de chaque modalite) et sept parametres cliniques, histologiques et therapeutiques ont ete consideres. En raison des differents scanographes et protocoles d’acquisition des institutions, nous avons utilise la methode ComBat pour harmoniser les parametres de texture. Resultats et analyse statistique En analyse unifactorielle, deux parametres issus de la TEP et deux de la scanographie etaient significativement predictifs du controle local, a l’inverse des variables cliniques. Le meilleur modele predictif du groupe d’apprentissage etait obtenu en associant deux parametres TEP (IC2 et strength), avec une sensibilite de 100 % et une specificite de 88 %, et un hazard ratio indefini (p Conclusion Notre etude a permis d’identifier deux parametres de textures derives de la TEP/scanographie comme facteurs predictifs independants associes a la recidive locale chez les patients atteints d’un cancer du poumon non a petites cellules traites par irradiation stereotaxique. Ce modele merite d’etre confirme sur une cohorte plus consequente et pourrait etre utilise en clinique pour guider une eventuelle escalade de dose.

Scientific Reports 6: Article number: 20927; published online: 18 February 2016; updated: 23 September 2016 The original version of this Article contained a typographical error in the spelling of the author E. Gazquez, which was incorrectly given as E. Gazguez. This has now been corrected in the PDFand HTML versions of the Article.

International audience; 1 Neural crest cells (NCCs) are a population of multipotent cells that migrate extensively during vertebrate development. Alterations to neural crest ontogenesis cause several diseases, including cancers and congenital defects, such as Hirschprung disease, which results from incomplete colonization of the colon by enteric NCCs (ENCCs). We investigated the influence of the stiffness and structure of the environment on ENCC migration in vitro and during colonization of the gastrointestinal tract in chicken and mouse embryos. We showed using tensile stretching and atomic force microscopy (AFM) that the mesenchyme of the gut was initially soft but gradually stiffened during the period of ENCC colonization. Second-harmonic generation (SHG) microscopy revealed that this stiffening was associated with a gradual organization and enrichment of collagen fibers in the developing gut. Ex-vivo 2D cell migration assays showed that ENCCs migrated on substrates with very low levels of stiffness. In 3D collagen gels, the speed of the ENCC migratory front decreased with increasing gel stiffness, whereas no correlation was found between porosity and ENCC migration behavior. Metalloprotease inhibition experiments showed that ENCCs actively degraded collagen in order to progress. These results shed light on the role of the mechanical properties of tissues in ENCC migration during development. Neural crest cells (NCCs) are essential to vertebrate development. This highly migratory and multipotent population of cells gives rise to craniofacial structures, cardiac and neuroendocrine derivatives, melanocytes, glial cells and neurons of the peripheral nervous system, as well as the intrinsic innervation of the digestive tract, the enteric nervous system (ENS). Different methods have been used to visualize NCCs and their derivatives, ranging from Le Douarin's historical chick-quail neural tube graft method

We present a novel elastography method for soft materials (100Pa-100kPa) based on indentation by a μm-sized water jet. We show that the jet creates a localized deformation ("cavity") of the material that can be easily visualized. We study experimentally how cavity width and depth depend on jet speed, height, incidence angle and sample elasticity. We describe how to calibrate the indenter using gels of known stiffness. We then demonstrate that the indenter yields quantitative elasticity values within 10% of those measured by shear rheometry. We corroborate our experimental findings with fluid-solid finite-element simulations that quantitatively predict the cavity profile and fluid flow lines. The water jet indenter permits in situ local stiffness measurements of 2D or 3D gels used for cell culture in physiological buffer, is able to assess stiffness heterogeneities with a lateral resolution in the range 50-500μm (at the tissue scale) and can be assembled at low cost with standard material from a biology laboratory. We therefore believe it will become a valuable method to measure the stiffness of a wide range of soft, synthetic or biological materials.

Introduction La TEP-DOPA demontre au quotidien ses excellentes performances diagnostiques dans le bilan lesionnel des TNE du grele. Si sa superiorite par rapport a la scintigraphie a l’Octreoscan® a deja ete demontree, ses performances par rapport a la TEP aux analogues de la somatostatine marques au 68Ga ne sont pas etablies. L’objectif de cette etude retrospective etait de comparer la TEP-DOPA a la TEP au 68Ga-DOTANOC chez des patients ayant beneficie des 2 examens pour une TNE de l’intestin moyen confirmee histologiquement. Materiels et methodes Vingt patients, 7 femmes et 13 hommes, d’âge median 61 ans, ont ete explores pour une TNE bien differenciee de l’intestin moyen de grade 1 (11 pts), de grade 2 (7 pts) et de grade non determine (2 pts) dans le cadre du bilan d’extension initial (5 pts), du suivi (12 pts) ou avant PRRT (3 pts). Le delai median entre les 2 TEP etait de 33,5 jours. Les TEP-DOTANOC etaient realisees dans le cadre d’un essai clinique (14 pts) ou d’ATU nominative (6 pts). Les TEP d’un meme patient ont ete analysees visuellement en prenant en compte le nombre de lesions, l’intensite de fixation et le contraste. Une lecture comparative lesion/lesion des deux examens etait ensuite realisee. Pour les foyers discordants, le gold standard utilise incluait les autres procedures d’imagerie, les donnees du suivi et de l’examen anatomo-pathologique. Resultats Au total, 17 TEP-DOPA se sont averees pathologiques contre 15 TEP-DOTANOC. Les examens etaient discordants pour 2 pts correspondant, respectivement, a une recidive metastatique focale et a une maladie residuelle focale, diagnostiquees uniquement en TEP-DOPA. Pour 18 autres pts, les examens etaient concordants, positifs dans 15 cas et negatifs dans 3 cas. Dans les 15 cas d’examens concordants, la TEP-DOPA etait jugee globalement superieure a la TEP-DOTANOC pour 6 pts (nettement dans 2 cas), inferieure pour 2 pts et similaire pour 4 pts. Chez 3 pts, les examens etaient complementaires avec des sensibilites variables selon les organes. Conclusion Dans les TNE de l’intestin grele, la TEP-DOPA semble globalement plus performante que la TEP-DOTANOC et constitue l’examen a proposer en premiere intention pour le bilan d’extension lesionnel. La TEP-DOTANOC peut neanmoins s’averer complementaire de la TEP-DOPA chez certains patients et apporte, dans tous les cas, des informations pronostiques et theranostiques complementaires, tres utiles pour la prise en charge therapeutique.

This Note presents experimental evidence that a hyperbolic tissue flow plays an important role in the establishment of the organization plan of vertebrates. We have followed the development of chicken embryos from the gastrula stage up to the moment when the body plan is recognizable. We have found that establishment of this plan occurs in the presence of a uniform tissue flow which at all stages presents a hyperbolic pattern. The flow is bidirectional in the antero-posterior direction, with a fixed point (stagnation point of the flow) which is a point of zero speed in all directions, in the reference frame of the egg. This stagnation point of the flow is located at the level of the presumptive yolk stalk of the chicken (analogous to the mammal navel). On either sides (left and right) of the body, the flow is also bidirectional. The antero-posterior bidirectionality and the left-right bidirectionality result in splitting of the embryo into four domains with vortex-like flow, with partial mirror symmetry between the left/right halves and top/bottom ones. The center of symmetry is the stagnation point. The broken symmetry of the flow is up-scaled in the adult animal. Areas with straightforward tissue movement are the ones where axial structures develop. The lateral domains with vortex-like flow colocalize with the future limb plates.

Several deconvolution algorithms are commonly used in aeroacoustics to estimate the power level radiated by static sources, for instance, the deconvolution approach for the mapping of acoustic sources (DAMAS), DAMAS2, CLEAN, and the CLEAN based on spatial source coherence algorithm (CLEAN-SC). However, few efficient methodologies are available for moving sources. In this paper, several deconvolution approaches are proposed to estimate the narrow-band spectra of low-Mach number uncorrelated sources. All of them are based on a beamformer output. Due to velocity, the beamformer output is inherently related to the source spectra over the whole frequency range, which makes the deconvolution very complex from a computational point of view. Using the conventional Doppler approximation and for limited time analysis, the problem can be separated into multiple independent problems, each involving a single source frequency, as for static sources. DAMAS, DAMAS2, CLEAN, and CLEAN-SC are then extended to moving sources. These extensions are validated from both synthesized data and real aircraft flyover noise measurements. Comparable performances to those of the corresponding static methodologies are recovered. All these approaches constitute complementary and efficient tools in order to quantify the noise level emitted from moving acoustic sources.

Objectifs Le but de cette etude etait d’etudier les performances diagnostiques et l’impact de la tep/tdm 68ga-psma sur la prise en charge des patients atteints de cancer de la prostate en recidive biochimique occulte (rbo). Methodes Au total, 130 patients en rbo (psa inferieur a 1,6 ng/mL) ont ete inclus dans cette etude ( NCT03443609 ). Initialement, tous les patients ont beneficie d’un traitement radical. Avant inclusion dans l’etude, les patients ont beneficie d’une mpirm pelvienne et d’une scintigraphie osseuse avec double temp/tdm et n’ont ete inclus que si ces 2 examens etaient normaux ou douteux. L’imagerie tep a ete realisee 1 et 2 heures apres l’injection de 68ga-psma. Les medecins referents des patients ont rempli des questionnaires (avant et apres tep) pour evaluer l’impact de cette imagerie sur la strategie therapeutique. Six mois apres la fin du traitement, il a ete realise un psa. Resultats Cinq mpirm et 2 scintigraphies osseuses ont ete positives chez 7 patients donc non incluables. Voici l’analyse des donnees des 52 premiers patients inclus : trente-huit d’entre eux (73 %) ont eu une tep/tdm 68ga-psma positive ; 94 lesions ont ete detectees, 53/94 (56,4 %) dans des ganglions lymphatiques (principalement en region pelvienne), 25/94 (26,6 %) dans les os (squelette axial) et 12/94 (12,7 %) dans la loge de prostatectomie. Les taux de detection des recidives ont ete de 56 %, 87 % et 74 % si psa entre [0,05–0,2 ng/mL], [0,2–0,6 ng/mL] et [0,6–1,6 ng/mL] respectivement. Grâce a la tep/tdm 68ga-psma, la prise en charge therapeutique a ete modifiee chez 67,3 % (35/52) des patients. Parmi les patients psma-positifs, 30,7 % (16/52) ont eu un taux de psa indetectable apres traitement focalise sur la (les) lesion(s) psma positive(s). Conclusion Trois points majeurs sont retenus : localisation de la recidive chez plus de la moitie des patients malgre un taux de psa inferieur a 0,2 ng/mL (taux limite de psa pour une radiotherapie de rattrapage), impact majeur de l’examen car changement de traitement chez plus de la moitie des patients et obtention d’un psa indetectable chez 30 % des patients.