CT-guided radiofrequency ablation for hepatocellular carcinomas that were undetectable at US: therapeutic effectiveness and safety.
OBJECTIVE
To determine the therapeutic effectiveness and safety of computed tomography (CT)-guided radiofrequency (RF) ablation for hepatocelluar carcinomas (HCCs) that were undetectable at ultrasonography (US).


METHODS
CT-guided RF ablation with use of internally cooled electrodes was performed in 66 patients with 97 HCCs (diameter range, 3-39 mm) in 78 sessions. Two radiologists retrospectively evaluated in consensus the presence or absence of local tumor progression as well as the complications at CT performed immediately after RF ablation and at 1-, 3-, 6-, and 12-month follow-up. The relationship between the occurrence of pneumothorax and the electrode length in the lung in patients treated with the transpulmonary approach was statistically evaluated with use of the Mann-Whitney test.


RESULTS
The technical success rate of CT-guided RF ablation immediately after RF ablation was 97% (94 of 97 HCCs). The primary technique effectiveness rates of complete ablation 1, 3, 6, and 12 months after RF ablation were 97% (94 of 97 HCCs), 94% (91 of 97 HCCs), 84% (81 of 96 HCCs), and 74% (66 of 89 HCCs), respectively. Major complications were observed in six of the 78 treatment sessions (7.7%). In five of these six sessions, pneumothorax developed immediately after RF ablation; the remaining complication was tumor seeding along the electrode tract. Self-limiting pneumothorax was observed in 12 of 38 sessions (32%) in which the transpulmonary approach was used. The electrode length in the lung was not statistically related to the occurrence of pneumothorax (P = .26).


CONCLUSIONS
For HCCs that are undetectable at US, CT-guided RF ablation is effective and relatively safe.
Park
Beom Jin
BJ
Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Byun
Jae Ho
JH
Jin
Yong Hyun
YH
Won
Hyung Jin
HJ
Shin
Yong Moon
YM
Kim
Kyoung Won
KW
Park
Sang Joon
SJ
Kim
Pyo Nyun
PN