Background and purpose: Thermal ablation (radiofrequency ablation

RFA/microwave ablation

MWA) is the most commonly used minimally invasive technique for the treatment of liver cancer. Real-time shear wave elastography (SWE) is a new type of ultrasonic imaging technology

which was used in our study to monitor thermal ablation of liver cancer. This study aimed to investigate the stiffness change of liver cancer and that of surrounding liver parenchyma before and after thermal ablation

and to evaluate the application of SWE for monitoring thermal ablation for liver cancer. Methods: From Oct. 2014 to Apr. 2015

a total number of 36 patients

with 39 lesions

were treated with RFA or MWA and got complete response. SWE examination was performed before and after ablation. The SWEmean

SWE-min

SWE-max

SWE-SD of lesions and the surrounding liver parenchyma were measured. Statistical analysis was made to compare the stiffness changes of liver cancer with those of the surrounding liver parenchyma before and after thermal ablation

and to determine whether there were differences between two different ablation modes. Results: Before and after ablation

the SWE-mean of lesions was (30.09±11.67) kPa vs (52.11±17.56) kPa

 SWE-min was (10.46±8.22) kPa vs (20.57±11.42) kPa

SWE-max was (51.50±20.84) kPa vs (88.54±27.75) kPa

SWESD was (10.63±4.30) kPa vs (16.89±7.72) kPa; There were statistically significant differences (P0.05). Before and after ablation

the SWE-mean of surrounding liver parenchyma was (8.84±2.82) kPa vs (8.91±2.78) kPa

SWE-min was (4.77±1.95) kPa vs (4.69±1.90) kPa

SWE-max was (13.82±3.79) kPa vs (14.34±3.97) kPa

SWE-SD was (3.24±1.32) kPa vs (3.37±1.29) kPa; There were no statistically significant differences (P0.05). After ablation

the SWE-mean of RFA and MWA was (45.55±10.91) kPa vs (60.59±20.99) kPa

SWE-min was (18.95±8.86) kPa vs (25.93±10.93) kPa

SWE-max was (76.58±15.51) kPa vs (104.01±32.59) kPa

SWE-SD was (13.82±3.52) kPa vs (20.85±9.77) kPa; There were statistically significant differences (P0.05). Conclusion: SWE can quantitively analyze the stiffness of lesions. The ablation zone became stiffer after RFA or MWA

and the ablation zone of MWA was stiffer than that of RFA. Two kinds of ablation methods did not significantly affect the stiffness of liver parenchyma around the lesion. SWE could potentially be used to monitor thermal ablation of liver cancer.