Hanan Hassan Fouad

BACKGROUND AND STUDY AIMS: Liver fibrosis is the underlying causeof hepatitis C virus (HCV)-related disease progression to endpoints such as cirrhosis, liver failure, and hepatocellular carcinoma. The aim of our study was to assess changes in hepatic fibrosis in patients with chronic HCV who had a fibrosis evaluation at two time points at least six months apart.

PATIENTS AND METHODS: This was a retrospective cohort study that included patients who had failed interferon therapy and received HCV retreatment with direct-acting antivirals (DAAs) at least six months later. Patients were evaluated previously for fibrosis according to liver biopsy and fibrosis biomarkers were evaluated before pegylated interferon and ribavirin (PEG/RBV) therapy. Fibrosis was re-evaluated with fibrosis-4 (FIB-4) scores before starting DAAs.

RESULTS: A total of 3,049 patients were included [age 43.47 ± 9.07 years, 55.20 % males] and baseline histopathology showed F1, F2, and F3 in 16.86 %, 46.21 %, and 36.93 %, respectively. The mean time interval between the last dose of previously failed IFN-therapy to the first dose of DAAs was 2.38 (±1.07) years. Overall, there was a significant increase in FIB-4 scores at retreatment times (from 11.71 ± 1.13 to 22.26 ± 1.68, p < 0.001). Patients with baseline FIB-4 < 1.45 (n = 1,569) and between 1.45 and 3.25 (n = 1,237) had significant increases in their FIB-4 at the retreatment time point [median difference; 0.41 (0.91) and 0.24 (1.5), p < 0.001, respectively], whereas patients with FIB-4 > 3.25 had significant reduction of their FIB-4 score at a retreatment timepoint [-0.98 (2.93), p ≤ 0.001].

CONCLUSION: Fibrosis progressed in most patients, even within six months for some patients, and this indicates retreatment of non-system vascular resistance patients even if they do not have significant fibrosis.

Stereotactic body radiation therapy (SBRT) is a precise and conformal radiation therapy (RT) that aims to deliver a high dose of radiation to the tumor whilst sparing surrounding normal tissue, making it an attractive option for head and neck cancer (HNC) patients who are not suitable for the traditional long course of RT with comprehensive RT target volume. Definitive SBRT for HNC has been investigated in different settings, including early stage glottis cancer, and as an alternative to brachytherapy boost after external beam RT. It is also used as a primary treatment option for elderly or medically unfit patients. More recently, an SBRT combination with immunotherapy in the neoadjuvant setting for HNC showed promising results. Salvage or adjuvant SBRT for HNC can be used in appropriately selected cases. Future studies are warranted to determine the optimum dose and fractionation schedules in any of these indications.

The fifth-order accurate Weighted Essentially Nonoscillatory space discretization developed by Jiang and Shu (WENO-JS) is studied theoretically. An exact Nonlinear Spectral Method (NSM) is developed based on an innovative yet simple methodology. The NSM explains the behaviour of nonsmooth solutions because it is valid for arbitrary modified wave numbers (MWN). The NSM clarifies the effects of the time integration methods and the Courant number. The mode isolation assumption, extensively used to analyse WENO-JS, is elucidated, and several novel findings are presented. The improved performance of the combination of WENO-JS with the forward Euler time integration method, compared to the Linear Fifth-Order Upwind discretization, is illustrated. The overdamping of the combination of WENO-JS with the popular third-order total variation diminishing Runge-Kutta method is discovered. Thus, the NSM covers several gaps in the current literature.