Role of B-mode ultrasound screening in detection of local tumor recurrence in the first year after radiofrequency ablation in the liver.
BACKGROUND
Ultrasound is known to be useful in imaging radiofrequency ablation (RFA) lesions intra- and postoperatively. The presented study intends to prove the value of ultrasound examination as a means of screening RFA-treated patients for local tumor recurrence.


METHODS
During a period of 47 months, 91 RFA treatments were performed in 61 patients in a single institution. Indications for RFA were hepatocellular carcinoma (74%), colorectal metastases (18%), recurrent cholangiocellular carcinoma (5%) and one neuroendocrine tumor metastasis as well as one metastasis of pancreatic cancer (1.5% each). RFA was only considered in non-resectable liver cancer. All applications were conducted under sonographic guidance following preoperative evaluation. Postoperative screening included sonographic examinations at intervals of 3, 6 and 12 months postoperatively, and further annual follow-up examinations. Mean follow-up period was 11.8 months.


RESULTS
Within the first 12 months after treatment, the lesions become more and more inhomogenous with mixed echogeneity. Occasionally, this evolves as a misleading finding, mimicking early tumor recurrence. To clarify suspicious cases (31%), magnetic resonance imaging (20%) or computed tomography (10%) was engaged. Ultrasound led to the detection of local tumor recurrence in 78% of recurrent HCC (13 patients), but only in 67% of metastatic diseases (3 patients). Overall local recurrence rate was 18%.


CONCLUSIONS
Ultrasound screening as a follow-up of primary hepatic malignancies is, due to its sensitivity, capable of detecting early local recurrence despite its low specifity. Appropriate application of particular criteria of local recurrence allows B-mode ultrasound to play a major role in screening RFA-treated patients.
Eisele
Robert M
RM
Department General, Visceral & Transplantation Surgery, Charité Virchow Clinic, Augustenburger Pl. 1, 13353 Berlin, Germany. robert_m.eisele@charite.de
Schumacher
Guido
G
Lopez-Hänninen
Enrique
E
Neuhaus
Peter
P
D017115:Catheter Ablation; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography / Q000379:methods