Thermal therapy induced fluid pressure and stress reductions in a solid tumor

• Published in: Microvascular research 2022-01, Vol.139, p.104250-104250, Article 104250
• Main Author: Jin, Z.-H.
• Format: Article
• Language: English
• Subjects: Computer Simulation; Elastic Modulus; Extracellular Fluid - metabolism; Hyperthermia, Induced; Interstitial fluid pressure reduction; Microcirculation; Models, Biological; Neoplasms - blood supply; Neoplasms - metabolism; Neoplasms - pathology; Neoplasms - therapy; Numerical Analysis, Computer-Assisted; Porosity; Pressure; Solid tumor; Stress reduction; Temperature; Thermal therapy; Thermoporoelasticity
• ISSN: 0026-2862; 1095-9319
• DOI: 10.1016/j.mvr.2021.104250

This paper presents an investigation on the interstitial fluid pressure and stress reductions in a vascularized solid tumor using a thermal therapy approach. The solid tumor is modeled as a fluid infiltrated poroelastic medium with a pressure source subjected to spatial heating. The distributions of temperature, interstitial fluid pressure, strains and stresses in a spherical tumor are obtained using a thermoporoelasticity theory in which the extracellular solid matrix and the interstitial fluid have different coefficient of thermal expansion (CTE). The numerical results for a solid tumor subjected to uniform spatial heating indicate that the CTE of the solid matrix of the tumor plays a crucial role in the reductions in the fluid pressure and effective stresses caused by the thermal therapy. The pore pressure and effective stresses are reduced when the CTE of the solid matrix is higher than that of the interstitial fluid. The reductions in fluid pressure and stresses may become significant depending on the difference between the CTEs of the solid matrix and interstitial fluid. The reductions reach the maximum at the tumor center and decrease with increasing radial distance from the tumor center. Finally, the thermally induced fluid flow is directed from the surface towards the center thereby potentially improving the microcirculation in the solid tumor. •A thermoporoelasticity model is developed for vascularized solid tumors.•TIF pressure and velocity obtained for a solid tumor undergoing hyperthermia.•The thermal therapy reduces TIF pressure and effective stresses.•Effects of differential CTE between the solid and interstitial fluid are examined.•Higher CTEs of the solid matrix leads to larger reductions in TIF pressure.