Radiofrequency ablation of hepatic metastases: factors influencing local tumor progression.
BACKGROUND
Although radiofrequency ablation (RFA) of nonresectable hepatic metastases has gained wide acceptance by showing survival benefit in selected patients, scattered reports are available regarding risk factors of local control of percutaneous RFA. The purpose of this study was to prospectively evaluate the factors influencing local tumor progression after percutaneous RFA of hepatic metastases.


METHODS
Sixty-nine hepatic metastatic lesions in 54 patients were treated by percutaneous RFA. Efficacy was evaluated by contrast-enhanced computed tomography or magnetic resonance imaging at 1 month after ablation, then at 3-month intervals for the first year and biannually thereafter.


RESULTS
The results of the log-rank test showed that tumor size of <3 cm (p = 0.024) and the absence of tumor contiguous with large vessels (p = 0.002) significantly correlated with local control for hepatic metastases. Cox regression analysis showed that the tumor size <3 cm and the absence of tumor contiguous with large vessels were independent factors (p = 0.055 and 0.009, respectively). The results of the log-rank test showed that neither the threshold post-ablation margin of 1.8 cm (p = 0.064) nor the presence of a tumor with subcapsular location (p = 0.134) correlated with the success of local control.


CONCLUSIONS
Percutaneous RFA is more effective in achieving local control in patients with hepatic metastases when the tumor size is <3 cm and not contiguous with large vessels.
Department of Radiology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan, R.O.C., cute610627@gmail.com.
Chang-Hsien
CH
Liu
Chih-Yung
CY
Yu
Wei-Chou
WC
Chang
Ming-Shen
MS
Dai
Cheng-Wen
CW
Hsiao
Yu-Ching
YC
Chou
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000009:adverse effects*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000150:complications / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009369:Neoplasms / Q000150:complications / Q000473:pathology / Q000601:surgery*; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology*; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors