The effect of 100 Hz magnetic field combined with X-ray on hepatoma-implanted mice.

Our previous cellular experiments demonstrated that 100 Hz magnetic field (MF) was effective at enhancing apoptosis of liver cancer cells BEL-7402 induced by X-ray irradiation. This study was performed to further explore the possible synergism between 100 Hz MF and X-ray in treatment of hepatoma-implanted Balb/c mice. 100 Hz MF exposure with a mean flux density of 0.7 mT was performed inside an energized solenoid coil. Six MV X-ray irradiation was generated using a linear accelerator. Tumor growth and survival of mice implanted with H22 cells were evaluated by measuring the tumor diameters and overall days of survival. Six groups treated with 100 Hz MF or X-ray alone or a combination of MF and X-ray were examined. Furthermore, the effects of different numbers of MF exposure periods on tumor growth and mice survival were examined when combined with 4 Gy X-ray. Data referring to overall survival days and tumor diameters of the above groups were compared using log-rank test and Student's t-test. Our results showed that five periods of combined 100 Hz MFs and 4 Gy X-ray could significantly extend the overall days of survival and reduce the tumor size compared to MF or X-ray alone. Also, a greater number of 100 Hz MF exposure periods could further improve the survival and inhibit tumor growth in hepatoma-implanted mice when combined with 4 Gy X-ray. In conclusion, these findings suggested that 100 Hz MF could possibly synergize with 4 Gy X-ray in terms of survival improvement and tumor inhibition in hepatoma-implanted mice.