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Time to surgery after termination of neoadjuvant chemoradiotherapy for esophageal cancer has traditionally been 4–6 weeks. Observational studies have suggested that delay of surgery for up to three months may lead to improved tumor regression and better outcomes. NeoRes II is the first randomized trial to address this in esophageal cancer. No difference in surgical morbidity or mortality between early and delayed surgery was reported in a previous publication from the trial. A multicenter clinical trial with randomized 1:1 allocation of standard time to surgery of 4–6 weeks, or delay of surgery to 10–12 weeks, after termination of chemoradiotherapy. The primary endpoint was complete histological tumor regression in patients with adenocarcinoma. Secondary endpoints included tumor regression grade, tumor free resection margins and overall survival in all patients, and stratified by histological subtype. In total 249 patients were randomized, 204 with adenocarcinoma and 45 with squamous cell carcinoma. There was no significant difference in histological complete response between adenocarcinoma patients allocated to standard time to surgery (20.6%) compared to delayed (25.6%) surgery (P = 0.18). Tumor free resection margin was achieved in 97.4% after standard time to surgery and 97.1% after delayed surgery (P = 1.0). The median follow-up time for survival was 51 months. Delayed time to surgery was associated with a 35% higher overall mortality, hazard ratio 1.35 (95% CI:0.94–1.95), (P = 0.11). No significant difference in complete histological tumor regression or tumor free resection margins comparing standard and delayed time to surgery after chemoradiotherapy was observed. There was a non-significant trend towards inferior overall survival after delayed surgery, suggesting caution in delaying surgery for more than 6 weeks after neoadjuvant chemoradiotherapy.

A wide range of problems in applied physics and engineering involve learning physical displacement fields from data. In this paper we propose a deep neural network-based approach for learning displacement fields in an end-to-end manner, focusing on the specific case of particle image velocimetry (PIV), a key approach in experimental fluid dynamics that is of crucial importance in diverse applications such as automotive, aerospace and biomedical engineering. The current state of the art in PIV data processing involves traditional handcrafted models that are subject to limitations including the substantial manual effort required and difficulties in generalizing across conditions. By contrast, the deep learning-based approach introduced in this paper, which is based on a recent optical flow learning architecture known as recurrent all-pairs field transforms, is general, largely automated and provides high spatial resolution. Extensive experiments, including benchmark examples where true gold standards are available for comparison, demonstrate that the proposed approach achieves state-of-the-art accuracy and generalization to new data, relative to both classical approaches and previously proposed optical flow learning schemes. Particle image velocimetry is an imaging technique to determine the velocity components of flow fields, of use in a range of complex engineering problems including in environmental, aerospace and biomedical engineering. A recurrent neural network-based approach for learning displacement fields in an end-to-end manner is applied to this technique and achieves state-of-the-art accuracy and, moreover, allows generalization to new data, eliminating the need for traditional handcrafted models.

Background Patients with locally advanced esophageal or gastroesophageal adenocarcinoma benefit from multimodal therapy concepts including neoadjuvant chemoradiation (nCRT), respectively, perioperative chemotherapy (pCT). However, it remains unclear which treatment is superior concerning postoperative morbidity. Methods In this study, we compared the postsurgical survival (30-day/90-day/1-year mortality) (primary endpoint), treatment response, and surgical complications (secondary endpoints) of patients who either received nCRT (CROSS protocol) or pCT (FLOT protocol) due to esophageal/gastroesophageal adenocarcinoma. Between January 2013 and December 2017, 873 patients underwent Ivor Lewis esophagectomy in our high-volume center. 339 patients received nCRT and 97 underwent pCT. After 1:1 propensity score matching (matching criteria: sex, age, BMI, ASA score, and Charlson score), 97 patients per subgroup were included for analysis. Results After matching, tumor response (ypT/ypN) did not differ significantly between nCRT and pCT (p = 0.118, respectively, p = 0.174). Residual nodal metastasis occurred more often after pCT (p = 0.001). Postsurgical mortality was comparable within both groups. No patient died within 30 or 90 days after surgery while the 1-year survival rate was 72.2% for nCRT and 68.0% for pCT (p = 0.47). Only grade 3a complications according to Clavien–Dindo were increased after pCT (p = 0.04). There was a trend towards a higher rate of pylorospasm within the pCT group (nCRT: 23.7% versus pCT: 37.1%) (p = 0.061). Multivariate analysis identified pCT, younger age, and Charlson score as independent variables for pylorospasm. Conclusion Both nCRT and pCT are safe and efficient within the multimodal treatment of esophageal/gastroesophageal adenocarcinoma. We did not observe differences in postoperative morbidity. However, functional aspects such as gastric emptying might be more frequent after pCT.

To better understand the complex flow in arteries it is necessary to analyze the fluid–structure interaction between the time dependent velocity field, the non-Newtonian fluid, and the elastic blood vessels and to investigate the wall-shear stress distribution that develops in the elastic vessel during an oscillation cycle. The scope of this study is to quantify the influence of the viscoelastic fluid properties on the fluid–structure interaction and the wall-shear stress of a straight elastic vessel by analyzing oscillatory flow of both a Newtonian reference fluid and a non-Newtonian fluid. Unlike in Womersley’s analyses, an elastic vessel of finite length with a non-Newtonian fluid is investigated in this study. Furthermore, quantitative benchmark data for numerical fluid–structure interaction methods are provided. Time-resolved particle-image velocimetry, static pressure measurements, and wall detection are used to measure the velocity field, the pressure distribution, and the vessel dilatation with high temporal and spatial resolution. The mechanical properties of the vessel material are determined by a dynamic mechanical analysis and the viscosities of the Newtonian and the non-Newtonian fluid are measured by a rheometer. The fluid–structure interaction is measured for a sinusoidal oscillating flow in a Reynolds number range 472 ≤ R e N F ≤ 971 and 503 ≤ R e N N F ≤ 1065 for the Newtonian reference fluid and the non-Newtonian fluid. The Womersley number range is 5 . 97 ≤ W o N F ≤ 8 . 53 for the Newtonian reference fluid and 6 . 14 ≤ W o N N F ≤ 8 . 79 for the non-Newtonian fluid. The results show that the wall-shear stress maximum increases up to 32%–38% for the non-Newtonian fluid despite a 10%–45% higher wall-shear rate for the Newtonian reference fluid. Furthermore, the amplitudes of the dilatation and the pressure in the vessel are more pronounced for the non-Newtonian fluid.