Spin-current vortices in current-perpendicular-to-plane nanoconstricted spin-valves

The charge and spin diffusion equations taking into account spin-flip and spin-transfer torque were numerically solved using a finite element method in complex non-collinear geometry with strongly inhomogeneous current flow. As an illustration, spin-dependent transport through a non-magnetic nanoconstriction separating two magnetic layers was investigated. Unexpected results such as vortices of spin-currents in the vicinity of the nanoconstriction were obtained. The angular variations of magnetoresistance and spin-transfer torque are strongly influenced by the structure geometry.Comment: 11 pages, 5 figure

Volumetric Enhancing Tumor Burden at CT to Predict Survival Outcomes in Patients with Neuroendocrine Liver Metastases after Intra-arterial Treatment

Purpose: To investigate whether liver enhancing tumor burden (LETB) assessed at contrast-enhanced CT indicates early response and helps predict survival outcomes in patients with multifocal neuroendocrine liver metastases (NELM) after intra-arterial treatment.Materials and Methods: This retrospective study included patients with NELM who underwent intra-arterial treatment with transarterial embolization (TAE) or chemoembolization (TACE) between April 2006 and December 2018. Tumor response in treated NELM was evaluated by using the Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST (mRECIST). LETB was mea-sured as attenuation 2 SDs greater than that of a region of interest in the nontumoral liver parenchyma. Overall survival (OS); time to unTA(C)Eable progression, defined as the time from the initial treatment until the time when intra-arterial treatments were considered technically unfeasible, either not recommended by the multidisciplinary tumor board or until death; and hepatic and whole-body progression-free survival (PFS) were evaluated using multivariable Cox proportional hazards analyses, the Kaplan-Meier method, and log-rank test.Results: The study included 119 patients (mean age, 60 years +/- 11 [SD]; 61 men) who underwent 161 treatments. A median LETB change of -25.8% best discriminated OS (83 months in responders vs 51 months in nonresponders; P = .02) and whole-body PFS (18 vs 8 months, respectively; P < .001). A -10% LETB change best discriminated time to unTA(C)Eable progression (32 months in re-sponders vs 12 months in nonresponders; P < .001) and hepatic PFS (18 vs 8 months, respectively; P < .001). LETB change remained independently associated with improved OS (hazard ratio [HR], 0.56), time to unTA(C)Eable progression (HR, 0.44), hepatic PFS (HR, 0.42), and whole-body PFS (HR, 0.47) on multivariable analysis. Neither RECIST nor mRECIST helped predict patient outcome. Conclusion: Response according to LETB change helped predict survival outcomes in patients with NELM after intra-arterial treat-ments, with better discrimination than RECIST and mRECIST

Gastric Juvenile Polyposis with High-Grade Dysplasia in Pachydermoperiostosis

Pachydermoperiostosis (PDP) is the primary form of hypertrophic osteoarthropathy. It is a very rare disease consisting of pachydermia, digital clubbing and radiologic periostosis. Various digestive symptoms in PDP are seen in 11–49% of patients and juvenile polyps may be found at gastric endoscopy. We report here the history of a patient with PDP who was referred for assessment of severe anemia. Endoscopy of the upper digestive tract showed multiple polyps of the stomach with two huge lesions exhibiting foci of high-grade dysplasia. This observation suggests that PDP can be considered as a precancerous condition of the stomach and systematic screening using endoscopy should be considered in these patients

Unravelling the pharmacologic opportunities and future directions for targeted therapies in gastro-intestinal cancers part 2: Neuroendocrine tumours, hepatocellular carcinoma, and gastro-intestinal stromal tumours.

Until the 1990s, cytotoxic chemotherapy has been the cornerstone of medical therapy for gastrointestinal (GI) cancers. Better understanding of the cancer cell molecular biology has led to the therapeutic revolution of targeted therapies, i.e. monoclonal antibodies or small molecule inhibitors directed against proteins that are specifically overexpressed or mutated in cancer cells. These agents, being more specific to cancer cells, were expected to be less toxic than conventional cytotoxic agents. However, their effects have sometimes been disappointing, due to intrinsic or acquired resistance mechanisms, or to an activity restricted to some tumour settings, illustrating the importance of patient selection and early identification of predictive biomarkers of response to these therapies. Targeted agents have provided clinical benefit in many GI cancer types. Particularly, some GI tumours are considered chemoresistant and targeted therapies have offered a new therapeutic base for their management. Hence, somatostatin receptor-directed strategies, sorafenib, and imatinib have revolutioned the management of neuroendocrine tumours (NET), hepatocellular carcinoma (HCC), and gastrointestinal stromal tumours (GIST), respectively, and are now used as first-line treatment in many patients affected by these tumours. However, these agents face problems of resistances and identification of predictive biomarkers from imaging and/or biology. We propose a comprehensive two-part review providing a panoramic approach of the successes and failures of targeted agents in GI cancers to unravel the pharmacologic opportunities and future directions for these agents in GI oncology. In this second part, we will focus on NET, HCC, and GIST, whose treatment relies primarily on targeted therapies

Antiproliferative Systemic Therapies for Metastatic Small Bowel Neuroendocrine Tumours

Neuroendocrine neoplasms (NENs) are a heterogeneous group of malignancies with rising incidence and prevalence. Outcome and therapy of small bowel neuroendocrine tumours (SBNETs) is variable, depending on the grade, differentiation, tumour burden, as well as the site of the tumour origin. Because of this, multidisciplinary approach is essential. Large randomized clinical trials, with somatostatin analogues (PROMID, CLARINET) or with peptide receptor radionuclide therapy (PRRT) with 177-lutetium (NETTER-1 trial) as well as the mammalian target of rapamycin inhibitor (mTOR) everolimus (RADIANT trials), represent milestones for the medical management of unresectable grade 1 and 2 SBNETS over the last decade. Novel therapies, such as tyrosine kinase inhibitors (TKI), are on the cutting edge. However, multiple unsolved questions remain. This review provides a comprehensive review of the main systemic therapeutic options for advanced SBNETs and discusses the latest guideline recommendations for palliative treatment

Morphological imaging and CT histogram analysis to differentiate pancreatic neuroendocrine tumor grade 3 from neuroendocrine carcinoma

International audiencePurpose: To compare morphological imaging features and CT texture histogram parameters between grade 3 pancreatic neuroendocrine tumors (G3-NET) and neuroendocrine carcinomas (NEC).Materials and methods: Patients with pathologically proven G3-NET and NEC, according to the 2017 World Health Organization classification who had CT and MRI examinations between 2006-2017 were retrospectively included. CT and MRI examinations were reviewed by two radiologists in consensus and analyzed with respect to tumor size, enhancement patterns, hemorrhagic content, liver metastases and lymphadenopathies. Texture histogram analysis of tumors was performed on arterial and portal phase CT images. images. Morphological imaging features and CT texture histogram parameters of G3-NETs and NECs were compared.Results: Thirty-seven patients (21 men, 16 women; mean age, 56±13 [SD] years [range: 28-82 years]) with 37 tumors (mean diameter, 60±46 [SD] mm) were included (CT available for all, MRI for 16/37, 43%). Twenty-three patients (23/37; 62%) had NEC and 14 patients (14/37; 38%) had G3-NET. NECs were larger than G3-NETs (mean, 70±51 [SD] mm [range: 18 - 196mm] vs. 42±24 [SD] mm [range: 8 - 94mm], respectively; P=0.039), with more tumor necrosis (75% vs. 33%, respectively; P=0.030) and lower attenuation on precontrast (30±4 [SD] HU [range: 25-39 HU] vs. 37±6 [SD] [range: 25-45 HU], respectively; P=0.002) and on portal venous phase CT images (75±18 [SD] HU [range: 43 - 108 HU] vs. 92±19 [SD] HU [range: 46 - 117 HU], respectively; P=0.014). Hemorrhagic content on MRI was only observed in NEC (P=0.007). The mean ADC value was lower in NEC ([1.1±0.1 (SD)]×10-3 mm2/s [range: (0.91 - 1.3)×10-3 mm2/s] vs. [1.4±0.2 (SD)]×10-3 mm2/s [range: (1.1 - 1.6)×10-3 mm2/s]; P=0.005). CT histogram analysis showed that NEC were more heterogeneous on portal venous phase images (Entropy-0: 4.7±0.2 [SD] [range: 4.2-5.1] vs. 4.5±0.4 [SD] [range: 3.7-4.9]; P=0.023).Conclusion: Pancreatic NECs are larger, more frequently hypoattenuating and more heterogeneous with hemorrhagic content than G3-NET on CT and MRI