Basically, after the activation, the absorbed energy is transferred from the sensitizer to molecular oxygen and generates the highly cytotoxic singlet oxygen (1O2), which causes the damage to mitochondria, lysosomes, plasma membrane and nuclei then leads to cell death and tumor destruction (Dougherty, Gomer et al. 1998, Brown, Brown et al. 2004). Different from photodynamic therapy, PAT therapy is based on conversion of absorbed energy in thermal (hyperthermia) to damage the tumor tissue while leave the neighboring cells intact (Kelkar and Reineke 2011). To help overcoming the limitation of the conventional treatment, thermal ablation therapy, which can ablate cancer cells at high temperatures (>45°C), may be able to offer a simple and invasive alternative therapy for those solid tumors (Li, Lu et al. 2010). Thermal ablation energy can be delivered by microwave, radiofrequency (RF), magnetic field, and near-infrared (NIR) light (Hirsch, Stafford et al. 2003). With microwave as the …show more content…
2000). This technique has been used for treatment of benign and malignant tumors of the liver, lung, kidney and thyroid nodules (Yang, Chen et al. 2014). To achieve the thermal effect through RF, an electrode is inserted into the tissue and applies a high frequency alternating current that agitate the ions within the tissue to cause the ions follow the change in the direction of the current, leading to frictional heating (Curley 2003). Hyperthermia with small magnetites was first performed by Gilchrist in 1957 (Gilchrist, Medal et al. 1957). Like the RF using alternating current, magnetic fluid hyperthermia generate the heat through an alternating magnetic field and the released thermal energy is depend on the size of the magnetic material and the strength of the applied magnetic filed (Johannsen, Thiesen et al. 2010). Among those, NIR light (wavelength 700-1100 nm) used for thermal cancer therapy is the most