title: Effect of tumor shape, size, and tissue transport properties on drug delivery to solid tumors.
abstract: BACKGROUND
  The computational methods provide condition for investigation related to the process of drug delivery, such as convection and diffusion of drug in extracellular matrices, drug extravasation from microvessels or to lymphatic vessels. The information of this process clarifies the mechanisms of drug delivery from the injection site to absorption by a solid tumor. In this study, an advanced numerical method is used to solve fluid flow and solute transport equations simultaneously to investigate the effect of tumor shape and size on drug delivery to solid tumor.
  
  
  METHODS
  The advanced mathematical model used in our previous work is further developed by adding solute transport equation to the governing equations. After applying appropriate boundary and initial conditions on tumor and surrounding tissue geometry, the element-based finite volume method is used for solving governing equations of drug delivery in solid tumor. Also, the effects of size and shape of tumor and some of tissue transport parameters such as effective pressure and hydraulic conductivity on interstitial fluid flow and drug delivery are investigated.
  
  
  RESULTS
  Sensitivity analysis shows that drug delivery in prolate shape is significantly better than other tumor shapes. Considering size effect, increasing tumor size decreases drug concentration in interstitial fluid. This study shows that dependency of drug concentration in interstitial fluid to osmotic and intravascular pressure is negligible.
  
  
  CONCLUSIONS
  This study shows that among diffusion and convection mechanisms of drug transport, diffusion is dominant in most different tumor shapes and sizes. In tumors in which the convection has considerable effect, the drug concentration is larger than that of other tumors at the same time post injection.
authors.affiliation: Department of Mechanical Engineering, K. N. T. University of Technology, Tehran, Iran.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Sefidgar
authors.affiliation: Department of Mechanical Engineering, K. N. T. University of Technology, Tehran, Iran ; Division of Nuclear Medicine, Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: M
authors.initials: M
authors.lastname: Soltani
authors.affiliation: Electrical & Computer Department of Ryerson University, Toronto, Ontario.
authors.forename: Kaamran
authors.initials: K
authors.lastname: Raahemifar
authors.affiliation: Department of Mechanical Engineering, K. N. T. University of Technology, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Bazmara
authors.affiliation: Department of Mechanical Engineering, K. N. T. University of Technology, Tehran, Iran.
authors.forename: Seyed Mojtaba Mousavi
authors.initials: SM
authors.lastname: Nayinian
authors.affiliation: Department of Mechanical Engineering, K. N. T. University of Technology, Tehran, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Bazargan
keywords: Drug concentration; Solid tumor; Tissue transport properties; Tumor shape and size