Ultrasound-guided ablative therapy for hepatic malignancies : a comparison of the therapeutic effects of microwave and radiofrequency ablation.
BACKGROUND
Radiofrequency ablation (RFA) is currently the most widely used thermal ablative technique for unresectable hepatic malignancies. However, microwave ablation (MWA) is also gaining popularity worldwide. With a cooled-tip electrode, MWA produces necrotic effects comparable to RFA without damaging soft tissues along the electrode track. In this study, the authors compared the efficacy of these two ablative modalities in the treatment of primary or secondary liver cancer.


METHODS
Ultrasound-guided MWA was employed to treat 230 cases of liver cancer with a total of 349 nodules and a diameter of 0.8-11.4 cm [mean: 5.7 +/- 2.1 cm]. Meanwhile, ultrasound-guided RFA was performed in 92 cases of liver cancer with 173 nodules in total and a diameter of 2.0-10.2 cm [mean: 5.4 +/- 1.9 cm]. The clinical data were retrospectively analyzed to identify the differences between MWA and RFA in terms of their operative safety, local ablative effect, cost efficiency, and cumulative survival rate.


RESULTS
The patient parameters were comparable. The area of coagulative necrosis was similar in both groups. The tumor complete ablation rate was 83.7% (292/349) for the MWA group and 86.7% (150/173) for the RFA group, which showed no significant difference (P = 0.75). The one-year and two-year cumulative survival rate were all comparable between the two groups (P = 0.66, P = 0.41), which were 90.0% (198/220), 81.6% (120/147) for the MWA group, and 91.8% (78/85), 81.0% (34/42) for the RFA group, respectively. Moreover, both the tumor type and number had no influence on survival rate for the two methods. In addition, there was no significant difference in complication rates between the two groups. The cost for performing one MWA procedure was about 40% lower than that of RFA ($1200 vs $2000).


CONCLUSIONS
Both MWA and RFA are safe and effective ablative treatments for liver cancer. Additionally, MWA has the advantage of cost efficiency.
X G
XG
Zhang
Z L
ZL
Zhang
S Y
SY
Hu
Y L
YL
Wang
D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D017115:Catheter Ablation / Q000379:methods*; D002681:China / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler / Q000379:methods*