Tumor dissemination after radiofrequency ablation of hepatocellular carcinoma (original) (raw)

The high incidence of tumor seeding along the needle tract, reported by Llovet et al., 1 has not been reported as a complication of radiofrequency (RF) ablation of hepatocellular carcinoma (HCC) with the cooled needle in studies that date from 1996 and include several hundred patients. 2-7 It was recently reported in preliminary form only for treatment of metastases. 8 The authors did not provide a convincing explanation for the discrepancy between their data and other series. The duration of the follow-up or a lack of accurate ultrasound (US) or computed tomography (CT) monitoring cannot account for the difference, because most studies were published more than 2 years ago and the follow-up is now far longer than that of the Barcelona experience. In our center, we started performing ethanol injection in 1986, laser thermal ablation in 1997, and RF thermal ablation with the cooled needle in 1999. To date, we have used RF in 63 patients with a total of 77 nodules; the follow-up averages 16 months (range, 1-42 months). Follow-up is performed with US every 3 months and spiral CT every 6 months. Among various minor and major complications including 1 death, we never saw tumor seeding along the needle tract. The absence of this complication in our and other experiences, in contrast with the Barcelona results, is probably due to the avoidance of direct puncture of subcapsular tumors, a criterion adopted by us and by other centers. Subcapsular HCC were reported previously to give a high incidence of complications at echoguided biopsy, 9 mainly hemorrhage and hemoperitoneum, and these complications were related to the size of the needle. Some cases of seeding were also reported after fine needle biopsy 10,11 and ethanol injection 12 of subcapsular HCC. Therefore, standard practice is to avoid their puncture, particularly when the needle cannot be introduced through a layer of nontumoral liver tissue. In fact, in the 4 HCC cases of the Barcelona group that showed seeding after the procedure, the authors state that it was not possible to perform thermocoagulation when retiring the needle, a procedure that is mandatory for avoiding neoplastic seeding. We are surprised at the high percentage of subcapsular HCC treated in the series of Llovet et al. (11 out of 32 patients!), considering that these tumors are the most favorable for resection. The conclusion that we draw from this study is that puncture of subcapsular HCC (and not only for RF ablation, which utilizes large-caliber needles) entails a high risk of hemoperitoneum, may facilitate neoplastic dissemination outside the liver capsule, and should be avoided. We agree that RF ablation should be considered an experimental procedure until further studies ascertain whether it is cost effective in comparison with ethanol injection or other local-regional treatments.