Tumor treatment by hyperthermia has limitations, however, that the most of nanoparticles do not have high specific absorption rate. At least 10% of tumor weight should be absorbed in order to be effective to heat-ablate tumors through hyperthermia. Treatment of malignant tumors at any site in the body is expected to be possible if agents that convert RF energy into heat can be delivered to the malignant cells. However, RF ablation suffers from the disadvantage that it is an invasive method that often requires insertion of electrodes into the body to deliver RF to the tumor sites. Superparamagnetic iron oxide nanoparticles of a correctly determined size are appropriate for in vivo hyperthermia applications, as they have no net magnetization without the external magnetic field. No net magnetization …show more content…
Photodynamic therapy is a new technology to treat tumor based on nanoparticle generated ROS at the tumor site. (Takahashi, Nagao et al. 2002; Oberdanner, Plaetzer et al. 2005) Photosensitizers, such as nanoparticles, can produce ROS when they are activated with the appropriate wavelength of excitation light. Nanoparticles as photosensitizers must be in close proximity to the tumor cells that they are usually administered at the tumor site directly. Photodynamic therapy is desirable in that it is relatively non-invasive and low toxicity. The major technical barrier, however, of this therapy is its difficulty in systemic introduction of photosensitizer to the tumor site and local irradiation to activate them. Tumors that have disseminated throughout the whole body may not be adequate for this therapy since the current technology is not available to irradiate the whole body. In addition, UV light is the wavelength of choice for the most of traditional photosensitizers that cannot efficiently penetrate into deep