Comparison of the presence and non-presence states of magnetite nanoparticles in tissue-equivalent breast phantom via radiofrequency hyperthermia

Breast cancer is a fatal disease and the leading cause of mortality in women. Radiofrequency hyperthermia is an approach to the treatment of cancer cells through increasing their temperature. The present study aimed to investigate breast tumor ablation via radiofrequency hyperthermia in the presence and non-presence states of magnetite nanoparticles and assess the effects of magnetite nanoparticles on breast cancer treatment in hyperthermia.

Radius hemisphere geometry (5 cm) was designed, which was similar to an actual breast based on the fat tissues, glandular tissues as a semi-oval embedded in the hemisphere, and a radius sphere (1 cm) as a tumor region inside. After utilization in a three-dimensional printer, each layer of the phantom was filled with a proper combination of oil-gelatin with similar dielectric and thermal properties to an actual breast. To evaluate the effects of the magnetite nanoparticles, three weights of the magnetite were added to the tumor region (0.01, 0.05, and 0.1 g). Finally, the phantom was placed in a radiofrequency device with the frequency of 13.56 MHz.

Temperature differences were measured at four different points of the phantom. The power and time in the treatment were estimated at 40 watts and five minutes, respectively. The temperature and specific absorption rate plots were obtained for all the states in several graphs for five minutes.The results showed that the heat generation with the utilization of the magnetite state was higher by approximately 2.5-7˚C compared to the state without magnetite. Furthermore, the temperature of 0.05 gram of magnetite indicated that without causing damage in the healthy tissues, the entire tumor region could attain adequate heat uniformly (6.1-6.4˚C).

Therefore, it could be concluded that 0.05 gram of magnetite could cause ablation in the entire tumor region.