Journal of Mechanical Science and Technology 28 (2) (2014) 763~771 www.springerlink.com/content/1738’494x DOI 10.1007/s12206’013’1141’4 Analysis of bioheat transfer equation for hyperthermia cancer treatment † Mohammad Mahdi Attar 1,* , Mohammad Haghpanahi 2 , Saeid Amanpour 3 and Mohammad Mohaqeq 2 1 Department of Mechanical Engineering, Hamedan Branch, Islamic Azad University, Hamedan, Iran 2 Biomechanic Group, School of Mechanical Engineering, Iran University of Science & Technology (IUST), Tehran, Iran   Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Iran (Manuscript Received May 29, 2012; Revised October 20, 2012; Accepted September 11, 2013) ’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’  Magnetic fluid hyperthermia is a new subclass of hyperthermia cancer treatment that can selectively heat up a tumor without damaging the surrounding healthy tissues. Some authors studied the temperature distribution of a magnetically mediated tumor assuming a homo’ geneous distribution of nanoparticles inside the tumor. Practically speaking, the injected nanoparticles do not usually distribute uniformly throughout the entire tumor, thus leaving some parts of the tumor without nanoparticles. In this study, an inhomogeneous dispersion of nanoparticles inside the tumor is assumed to investigate the tissues’ temperature profiles. The problem is solved for polar coordinate. Also in this study, the heating effect of magnetic fluid in a porcine liver tissue is experimentally examined. Numerical transient solutions are found to be in good agreement with experimental data. Keywords: Bioheat transfer; Hyperthermia; Finite element solution; Cancer treatment; Magnetic fluid ))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))   Hyperthermia is the procedure of raising temperature of cancerous tissue to 40’43˚C for therapeutic reason. It has been shown in many studies that high temperatures can cause direct damage to cancerous cells or sensitize them to other cancer treatment modalities [1]. That’s why hyperthermia is usually used in conjunction with other conventional therapies such as chemotherapy or/and radiotherapy [2]. For instance, it has been demonstrated that cytotoxicity of many chemotherapeu’ tic agents is maximized at temperatures between 40.5˚C and 43.0˚C [3]. Hyperthermia also enhances the radio’sensitivity in hypoxic, low’pH areas of cancerous tissues [4]. Hyperther’ mia is a viable cancer treatment for localized malignant tu’ mors and its success has been reported for head and neck can’ cer, breast cancer, urogenital tract cancer, melanoma and sar’ coma [5]. Various methods exist to deliver heat to target tissue. The most commonly used are focused ultrasound heating, laser heating and microwave heating. However, these methods cannot overcome the major challenge of hyperthermia which is minimizing the damage to surrounding healthy tissue. More than 50 years ago, Gilchrist raised the hope to solve this diffi’ culty by the use of magnetic principles [6]. When exposed to an alternating magnetic field, nano’sized magnetic particles generate heat by certain mechanisms. Superparamagnetic iron oxide nanoparticles (SPIONs: ferromagnetic particles with diameter less than 20 nm) are the most widely used particles in hyperthermia due to their extraordinary specific absorption rate (SAR [w/g]). Main mechanisms of heat dissipation in AC magnetic field for superparamagnetic nanoparticles are Brownian motion and Neel relaxation losses [7]. Andreas Jordan et al have done a great review on the basics of mag’ netic fluid hyperthermia using biocompatible superparamag’ netic particles [8]. Rosensweig has developed analytical rela’ tionships and computations of power dissipation of magnetic fluid subjected to AC magnetic field [9]. Magnetite (Fe 3 O 4 ) and maghemite (Fe 2 O 3 ) are the best candidates for magnetic hyperthermia due to their bio’compatibility. Goya et al pre’ sented a study of power absorption efficiency in several mag’ netite’based colloids to assess their potential to be used in hyperthermia [10]. However, other materials such as iron al’ loyed with cobalt, nickel and platinum are being investigated to be used in magnetic fluid hyperthermia. For example, Cabuil et al introduced a magnetic fluid based on cobalt ferrite nanoparticles and demonstrated their potential application in magnetic hyperthermia [11]. Magnetic nanoparticles can be coated with biological molecules, and due to their small size they can get close to any biological entity to interact with or bind to them, thereby providing a controllable means of “tag’ ging” or addressing it. Moreover, coating superparamagnetic nanoparticles with porous layers has been explored as a way to enhance hyperthermic chemotherapy. One of the most in’ teresting characteristics of these composite nanoparticles is * Corresponding author. Tel.: +98 9188170141, Fax.: +98 8114494185 E’mail address: d.attar.iauh@gmail.com † Recommended by Associate Editor Dongsik Kim © KSME & Springer 2014