Redo Craniotomy or Bevacizumab For Symptomatic Steroid Refractory True Or Pseudoprogression Following IMRT For Glioblastoma

Objective There is minimal evidence to support decision-making for symptomatic steroid-refractory pseudoprogression or true progression occurring after IMRT for glioblastoma (GBM). This study audited the survival outcome of patients managed with redo craniotomy (RedoSx) or Bevacizumab (BEV) for steroid-refractory mass effect after IMRT for GBM. Methods Patients with GBM managed between 2008 and 2019 with the EORTC-NCIC Protocol were entered into a prospective database. Patients with symptomatic steroid-refractory mass effect within 6 months of IMRT managed with either RedoSx or BEV were identified for analysis. For the primary endpoint of median overall survival (OS) post intervention, outcome was analysed in regards to potential prognostic factors, and differences between groups assessed by log-rank analyses. Results Of 399 patients managed with the EORTC-NCIC Protocol, 78 required an intervention within 6 months of IMRT completion for either true or pseudoprogression (49 with RedoSx and 29 with BEV). Subsequently 20 of the 43 patients managed with RedoSx when BEV was clinically available, required salvage with BEV within 6 months after RedoSx. Median OS post intervention was 8.7 months (95%CI: 7.84-11.61) for the total group; and 8.7 months (95%CI: 6.8-13.1) for RedoSx and 9.4 months (95%CI: 7.8-13.6) for BEV (p=0.38). Subsequent use of BEV in RedoSx patients was not associated with improved survival compared with RedoSx alone (p=0.10).Age, time from IMRT, and ECOG performance status were not associated with OS. In the RedoSx patients, immunohistochemical features such as Ki67% reduction correlated with survival. Presence of pure necrosis and residual tumour cells only had improved survival compared with presence of gross tumour (p<0.001). Conclusions At time of symptomatic steroid-refractory true or pseudoprogression following IMRT for GBM, BEV was equivalent to RedoSx in terms of OS. Pseudoprogression with residual cells at RedoSx was not associated with worse outcome compared to pure necrosis.

Comparison of Dental Prostheses Cast and Sintered by SLM from Co-Cr-Mo-W Alloy

The article presents the results of a comparative analysis of the metal substructure for dental prosthesis made from a Co-Cr-Mo-W alloy by two techniques, i.e. precision investment casting and selective laser melting (SLM). It was found that the roughness of the raw surface of the SLM sinter is higher than the roughness of the cast surface, which is compensated by the process of blast cleaning during metal preparation for the application of a layer of porcelain. Castings have a dendritic structure, while SLM sinters are characterized by a compact, fine-grain microstructure of the hardness higher by about 100 HV units. High performance and high costs of implementation the SLM technology are the cause to use it for the purpose of many dental manufacturers under outsourcing rules. The result is a reduction in manufacturing costs of the product associated with dental work time necessary to scan, designing and treatment of sinter compared with the time needed to develop a substructure in wax, absorption in the refractory mass, casting, sand blasting and finishing. As a result of market competition and low cost of materials, sinter costs decrease which brings the total costs related to the construction unit making using the traditional method of casting, at far less commitment of time and greater predictability and consistent sinter quality.

Use of Composite SiO2 (62-68)-MgO + CaO (29-39) in Ceramic Protection Mass Injection Machines in the Iron Notch and Liquid Slag Hole in Blast Furnaces

The article describes the use of protection ceramic composed of SiO2 (62-68)-MgO+CaO (29-39) in the frontal region of machines that inject refractory mass to stop pig iron running and liquid slag in blast furnaces. The new protection model (prototype) showed an annual saving of approximately R$ 32,000 compared to the compound previously used CaO-Al2O3-SiO2. It also presented lower toxicity, once it has in its morphology less amount of fiber. These fibers when inhaled cause damage to internal lungs tissues becoming harmful to health. Production rates remained, since in all the new ceramic protection samples that were tested the frontal part was preserved allowing the refractory mass to be injected in proper quantity and pressure for reconstitution of the hole length, which removes iron and slag from blast furnace. Therefore, this enables a larger internal volume in order to produce more. The protection models used were from the company Morganite-Brasil. The material morphology and crystallographic characterization were realized by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD), respectively.

Determination of Unit Pressure Force in Material Volume in the Course of Refractory Stamping Press Moulding

The paper presents results of assessment of the unit pressure force within the refractory material volume in the course press-moulding of stampings for refractory precast shapes. The force was evaluated with the use of physical simulation of deformation undergone by lead balls placed in the raw refractory mass subjected to pressing in a metal die. To determine the value of unit pressure force applied to the aggregate grains in the course of stamping press-moulding, physical model of deformation of a sphere induced by the uniaxial stress state was used.