Eldon David Lehmann PhD, FRCR, Presenter: Nothing to Disclose

John Robert Kachura MD, Abstract Co-Author: Nothing to Disclose

Martin E. O'Malley MD, Abstract Co-Author: Nothing to Disclose

J Robert Beecroft MD, Abstract Co-Author: Nothing to Disclose

C. S. Ho MD, Abstract Co-Author: Nothing to Disclose

To determine primary treatment effectiveness, incidence of local hepatic metastatic progression, and survival in patients with neuroendocrine tumor (NET) liver metastases treated with radiofrequency ablation (RFA).

At our two hospitals, a prospective liver RFA database has been maintained since November 1999. This was analyzed to March 2007 to identify NET patients who underwent RFA of liver metastases. We reviewed 25 procedures on 21 metastases in 12 consecutive patients. Metastases were treated with LeVeen electrodes (Boston Scientific, Natick, MA) n=21 (84%) and Cool-tip electrodes (Tyco Healthcare, Mansfield, MA) n=4 (16%). Seventeen RFAs (68%) were done percutaneously, and 8 (32%) at surgery. Imaging guidance was used as follows: US 11 (44%), CT 2 (8%), CT+US 4 (16%), and open US 8 (32%); four (16%) RFAs were performed at liver resection. Six patients had liver embolization or resection 1.4-29.5 months before RFA. Primary treatment effectiveness was defined as no local viable tumor on the first CT/MRI >24 hours and <3 months after RFA.

Mean patient age was 54 (38-75) years (4 males, 8 females). On average, patients had 1.8 metastases and 2.1 procedures; each metastasis receiving 1.2 treatments, and 1.6 (range 1-4) applications of RFA per session. Mean metastasis diameter was 2.4 (range 1.1-6.0) cm. Primary treatment effectiveness was 71%. There were no deaths or major complications. By the census follow-up date, 8 treated metastases demonstrated no local progression. Mean follow-up with serial CT/MRI was 22 (0.5-80) months, after the last RFA. Mean time from first imaging diagnosis of NET liver metastases to follow-up was 45 (12.5-109.5) months (1-9 years). At the latest follow-up, as of April 2007, all patients were alive.

Our 7-year experience with this rare tumor shows that it is possible to safely control small NET liver metastases with RFA. RFA can also facilitate debulking of more extensive NET liver metastases when combined with surgery.

Percutaneous RFA can be safe and effective in treating NET liver metastases. At our hospitals, RFA is now the first-line non-surgical treatment offered to NET patients with small liver metastases.

Lehmann, E, Kachura, J, O'Malley, M, Beecroft, J, Ho, C, Radiofrequency Ablation of Hepatic Neuroendocrine Tumor Metastases: A 7-Year Experience.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5009788.html