Evaluation of liver tumour response by imaging

Abstract

The goal of assessing tumour response on imaging is to identify patients who are likely to benefitor notfrom anticancer treatment, especially in relation to survival. The World Health Organization was the first to develop assessment criteria. This early score, which assessed tumour burden by standardising lesion size measurements, laid the groundwork for many of the criteria that followed. This was then improved by the Response Evaluation Criteria in Solid Tumours (RECIST) which was quickly adopted by the oncology community. At the same time, many interventional oncology treatments were developed to target specific features of liver tumours that result in significant changes in tumours but have little effect on tumour size. New criteria focusing on the viable part of tumours were therefore designed to provide more appropriate feedback to guide patient management. Targeted therapy has resulted in a breakthrough that challenges conventional response criteria due to the non-linear relationship between response and tumour size, requiring the development of methods that emphasize the appearance of tumours. More recently, research into functional and quantitative imaging has created new opportunities in liver imaging. These results have suggested that certain parameters could serve as early predictors of response or could predict later tumour response at baseline. These approaches have now been extended by machine learning and deep learning. This clinical review focuses on the progress made in the evaluation of liver tumours on imaging, discussing the rationale for this approach, addressing challenges and controversies in the field, and suggesting possible future developments.

Effect of magnetic field on holographic insulator/superconductor phase transition in higher dimensional Gauss–Bonnet gravity

“…However, we note that the effect of magnetic field in Gauss-Bonnet (GB) gravity in arbitrary spacetime dimensions would be important to look at. The reason for this is that GB gravity is a higher curvature gravity theory in higher spacetime dimensions and the Mermin-Wagner theorem claims that the phase transition is affected by higher curvature corrections [7]. Study incorporating the GB gravity background effects on holographic insulator/superconductor phase transition without magnetic field in higher dimensions has been done in [33].…”

Holographic superconductor from a noncommutative-inspired anti-de Sitter–Einstein–Born–Infeld black hole

“…Conductivity is one the main properties that characterize holographic superconductors and it is a natural consequence of the AdS/CFT correspondence [34][35][36][37][38]. This property has been extensively discussed for several configurations of black holes, including non-linear electrodynamics, higher curvature terms, Horava-Lifshitz gravity and Maxwell strength field corrections [8,14,18,27,[39][40][41][42]; in the following we consider conductivity in the probe limit. Assuming the standard Ansatz A µ = (φ, 0, δA x , 0) where δA x := δAe −iωt+iky is the perturbation of the gauge potential in coordinates (t, r, x, y), a straightforward calculation shows that in the case of BI electrodynamics the gauge perturbation δA must satisfy the following differential equation…”

“…In the original analysis by Gubser [7] using Maxwell electrodynamics, the probe limit was introduced where back-reaction contributions to the background metric due to the bulk fields are neglected; the probe limit simplifies the analysis of the holographic superconductor while keeps most of the interest- * Electronic address: mmac@xanum.uam.mx † Electronic address: selp@xanum.uam.mx ing physics. Following this approach and a matching procedure for the solutions [8][9][10], both Maxwell and Born-Infeld (BI) electrodynamics [11] have been considered in the literature [12][13][14][15][16][17][18].…”

“…As it is well-known, BI electrodynamics is a generalisation of Maxwell's electrodynamics, has no birefringence and provides a regularisation of the self-energy of a point-like charge [26]; the strength of the electric field, measured by the BI parameter b, is finite at the location of the source. Previous analyses of holographic superconductors based on BI electrodynamics exist [27] and also including other modifications [8,14]. In our treatment, we follow a nonperturbative approach on the BI parameter b to calculate the expectation value of the condensation operator according to the AdS/CFT duality [28,29].…”

Instability of Higgs vacuum via string cloud

“…On the other hand, the inhomogeneous vacuum decay, initiated by [3], can occur in nature. The idea was later applied to phenomenological model building [4] and the vacuum decay in string theories [5] and gravity theories [6,7,8,9,10]. Among them, the black hole catalysis discussed in [6,7] is interesting because it is generally applicable to various settings; The catalysis seeded by a topological soliton [3,4] highly depends on the structure of the potential.…”