Effect of the combination of 6 MeV radiotherapy with hyperthermia and gold nanoparticles on the MCF-7 breast cancer cells

Introduction: Combining radiotherapy as one of the main modalities used for cancer treatment with other modalities such as hyperthermia has recently played a special role in reducing side effects and improving treatment outcomes. In addition, Gold nanoparticles (GNPs) have also attracted attention as suitable clinical agents for enhancing the effect of radiotherapy in treating various cancers. The purpose of this study was to investigate the effect of combination of radiotherapy with both of the hyperthermia and GNPs for the treatment of MCF-7 breast cancer cells. Materials and Methods: We evaluated the cell death of MCF-7 breast cancer cells when treated with 6 MeV radiation therapy and 13.56 MHz capacitive radiofrequency hyperthermia in the presence of 20 nm GNPs with the lowest toxicity concentration. Initially, the cells were incubated with 20 mg/L GNPs for 24 hours. Then, they were exposed to RF hyperthermia with a power of 200 W for 15 min. Afterward, they were exposed to 6 MeV electron beam produced by a linear accelerator with a dose of 2Gy. Results: Our primary results showed that the presence of GNPs in the cancer cells and also thermal sensitizations provided by hyperthermia increases the rate of the MCF7 cancerous cell death and also the therapeutic efficiency. Conclusion: The combination of the two sensitizing modalities, i.e. radiofrequency hyperthermia and GNPs could be regarded for better delivery of the highest dose to the target while maintaining the lowest dose to adjustments normal organs/tissues as risk in the future. However this would require more in vivo animal studies as well as clinical human investigations.