%0 Journal Article
%T Thermal Distribution of Ultrasound Waves in Prostate Tumor: Comparison of Computational Modeling with In Vivo Experiments
%A Forough Jafarian Dehkordi
%A Ali Shakeri-Zadeh
%A Samideh Khoei
%A Hossein Ghadiri
%A Mohammad-Bagher Shiran
%J ISRN Biomathematics
%D 2013
%R 10.1155/2013/428659
%X Ultrasound irradiation to a certain site of the body affects the efficacy of drug delivery through changes in the permeability of cell membrane. Temperature increase in irradiated area may be affected by frequency, intensity, period of ultrasound, and blood perfusion. The aim of present study is to use computer simulation and offer an appropriate model for thermal distribution profile in prostate tumor. Moreover, computer model was validated by in vivo experiments. Method. Computer simulation was performed with COMSOL software. Experiments were carried out on prostate tumor induced in nude mice (DU145 cell line originated from human prostate cancer) at frequency of 3£¿MHz and intensities of 0.3, 0.5, and 1£¿w/cm2 for 300 seconds. Results. Computer simulations showed a temperature rise of the tumor for the applied intensities of 0.3, 0.5 and 1£¿w/cm2 of 0.8, 0.9, and 1.1¡ãC, respectively. The experimental data carried out at the same frequency demonstrated that temperature increase was 0.5, 0.9, and 1.4¡ãC for the above intensities. It was noticed that temperature rise was very sharp for the first few seconds of ultrasound irradiation and then increased moderately. Conclusion. Obtained data holds great promise to develop a model which is able to predict temperature distribution profile in vivo condition. 1. Introduction Prostate cancer is one of the most common malignant cancers in men [1]. There are a variety of treatments for prostate cancer among which chemotherapy is one of the most important methods. Application of chemotherapy for treatment of cancer is associated with some limitations. Today, drug targeting towards cancer cells and increasing drug concentration inside the tumor are the greatest purposes of researchers because systematic distribution of the anticancer agent may induce damages in normal tissue [2, 3]. Application of ultrasound is one of the basic techniques which has been used to increase the efficiency of drug delivery [4]. Traditionally, ultrasound waves have been used either for ultrasound hyperthermia or physiotherapy to warm the tissue or to kill cancerous cells [5]. Due to the ability of deep penetration into the living tissues, application of ultrasound wave has recently become an interesting area in noninvasive treatment and diagnostic medicine [6]. Ultrasound wave can deliver mechanical energy into the desired area inside the body. Absorption of ultrasound mechanical energy can increase tissue temperature to a relatively high value which may be used in therapy [7]. In drug delivery, ultrasound waves vibrate drug carriers and
%U http://www.hindawi.com/journals/isrn.biomathematics/2013/428659/