Abstract: Objective To investigate the clinical efficacy and safety of radiofrequency ablation (RFA) combined with low frequency ultrasound radiation with microbubble for the treatment of malignant liver neoplasms.
Methods The clinical data of 25 patients with malignant liver neoplasms who received RFA combined with low frequency ultrasound radiation with microbubble at the Kunming General Hospital from January 2010 to June 2011 were retrospectively analyzed. RFA was firstly performed with ultrasonic guidance, and then low frequency ultrasound radiation with microbubble was performed according to the results of ultrasound contrast examination 1 week after RFA. Ultrasound contrast examination was performed and the hepatic function and serum alpha fetoprotein (AFP) were assayed before operation, 3 and 6 months after operation, respectively. All data were analyzed using the  t test or chisquare test.
Results The gross tumor volumes of 16 patients reduced by 30% at 3 months after operation when compared with that before operation. The gross tumor volumes of 17 patients reduced by 50% at 6 months after operation when compared with that before operation. The gross tumor volume of 7 patients reduced, but tissues surrounding tumors showed the signal of bloodstream. The gross tumor volume of 1 patient did not reduce.The levels of aspartate aminotransferase (AST), total bilirubin (TBil) and alpha fetoprotein (AFP) at 3 months after operation were significantly lower than those before operation (t=23.51, 13.79, 257.07, P<0.05).The levels of alanine aminotransferase (ALT), AST, TBil and AFP at 6 months after operation were significantly  lower than those before operation (t=5.67, 27.19, 21.02, 333.46, P<0.05). No local recurrence was detected during a follow up of 6 months. The scores of quality of life (QOL) were very good in 21 (84.0%) patients, good in 2 (8.0%) patients, fair in 1 (4.0%) patient and poor in 1 (4.0%) patient. The scores of Karnofsky (KPS) were improved in 19 (76.0%) patients, stable in 5 (20.0%) patients and aggravated in 1 (4.0%) patient. There were significant differences in QOL and KPS between preand postoperation (χ2=41.600, 18.960, P<0.05).
Conclusion RFA combined with low frequency ultrasound radiation with microbubble is effective in reducing the tumor size and protect the hepatic function for patients with malignant liver neoplasms.