Evidence for radiofrequency ablation for Tumours

 

Imaging-guided Radiofrequency Ablation of Renal Masses¹

Ronald J. Zagoria, MD

¹ From the Department of Radiology, Wake Forest University Health Sciences, Medical Center Blvd, Winston-Salem, NC 27157-1088. Received February 25, 2004; revision requested April 2 and received May 11; accepted May 19. The author has no financial relationships to disclose. Address correspondence to the author (e-mail: rzagoria@wfubmc.edu).

Substantial and growing evidence indicates that imaging-guided percutaneous radiofrequency ablation of small renal cell carcinomas (RCCs) is effective for complete tumor eradication. The rate of successful radiofrequency treatment of small RCCs ranges from 79% to 97%, with a 1% rate of serious complications. For patients who are considered high-risk candidates for nephrectomy, percutaneous radiofrequency ablation represents another treatment option. The article summarizes the published results for this technique and also describes the indications, techniques, procedural risks, and applications for percutaneous radiofrequency ablation of RCCs. The successful use of radiofrequency ablation for treatment of recurrent and metastatic RCCs is also described.

© RSNA, 2004

Evidence-based Practice

Metastatic Colorectal Carcinoma: Cost-effectiveness of Percutaneous Radiofrequency Ablation versus That of Hepatic Resection¹

G. Scott Gazelle, MD, MPH, PhD, Pamela M. McMahon, BS, Molly T. Beinfeld, MPH, Elkan F. Halpern, PhD and Milton C. Weinstein, PhD

¹ From the Institute for Technology Assessment and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Zero Emerson Place, Suite 2H, Boston, MA 02114 (G.S.G., P.M.M., M.T.B., E.F.H.); and Center for Risk Analysis and Department of Health Policy & Management, Harvard School of Public Health, Boston, Mass (G.S.G., P.M.M., M.C.W.). Received December 17, 2003; revision requested February 24, 2004; revision received March 9; accepted April 12. Supported in part by the National Cancer Institute under R01-CA/HS83960 and the U.S. Department of the Army under DAMD 17-99-2-9001. Address correspondence to G.S.G.

PURPOSE: To evaluate the relative cost-effectiveness of radiofrequency (RF) ablation and hepatic resection in patients with metachronous liver metastases from colorectal carcinoma (CRC) and compare the outcomes, cost, and cost-effectiveness of a variety of treatment and follow-up strategies.

MATERIALS AND METHODS: A state-transition decision model for evaluating the (societal) cost-effectiveness of RF ablation and hepatic resection in patients with CRC liver metastases was developed. The model tracks the presence, number, size, location, growth, detection, and removal of up to 15 individual metastases in each patient. Survival, quality of life, and cost are predicted on the basis of disease extent. Imaging, ablation, and resection affect outcomes through detection and elimination of individual metastases. Several patient care strategies were developed and compared on the basis of cost, effectiveness, and incremental cost-effectiveness (expressed as dollars per quality-adjusted life-year [QALY]). Extensive sensitivity analysis was performed to evaluate the impact of alternative scenarios and assumptions on results.

RESULTS: A strategy permitting ablation of up to five metastases with computed tomographic (CT) follow-up every 4 months resulted in a gain of 0.65 QALYs relative to a no-treat strategy, at an incremental cost of $2400 per QALY. Compared with this ablation strategy, a strategy permitting resection of up to four metastases, one repeat resection, and CT follow-up every 6 months resulted in an additional gain of 0.76 QALYs at an incremental cost of $24 300 per QALY. Across a range of model assumptions, more aggressive treatment strategies (ie, ablation or resection of more metastases, treatment of recurrent metastases, more frequent follow-up imaging) were superior to less aggressive strategies and had incremental cost-effectiveness ratios of less than $35 000 per QALY. Findings were insensitive to changes in most model parameters; however, results were somewhat sensitive to changes in size thresholds for RF ablation, the number of metastases present, and surgery and treatment costs.

CONCLUSION: RF ablation is a cost-effective treatment option for patients with CRC liver metastases. However, in most scenarios, hepatic resection is more effective (in terms of QALYs gained) than RF ablation and has an incremental cost-effectiveness ratio of less than $35 000 per QALY.

© RSNA, 2004

Index terms: Cost-effectiveness • Economics, medical • Liver neoplasms, 761.33 • Liver neoplasms, therapy, 761.1269 • Radiofrequency (RF) ablation, 761.1269

Vascular and Interventional Radiology

Percutaneous Radio-frequency Ablation of Hepatic Metastases from Colorectal Cancer: Long-term Results in 117 Patients¹

Luigi Solbiati, MD, Tito Livraghi, MD, S. Nahum Goldberg, MD, Tiziana Ierace, MD, Franca Meloni, MD, Marina Dellanoce, MD, Luca Cova, MD, Elkan F. Halpern, PhD and G. Scott Gazelle, MD, MPH, PhD

¹ From the Department of Radiology, Ospedale Generale, Busto Arsizio, Italy (L.S., T.I., M.D., L.C.); Department of Radiology, Ospedale Civile, Vimercate, Italy (T.L., F.M.); Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Mass (S.N.G.); Decision Analysis and Technology Assessment Group, Department of Radiology, Massachusetts General Hospital, Zero Emerson Pl, Suite 2H, Boston, MA 02114 (E.F.H., G.S.G.); and Department of Health Policy and Management, Harvard School of Public Health, Boston, Mass (G.S.G.). From the 1999 RSNA scientific assembly. Received October 5, 2000; revision requested November 22; revision received February 15, 2001; accepted April 3. S.N.G. supported by Radionics. Address correspondence to G.S.G.

PURPOSE: To describe the results of an ongoing radio-frequency (RF) ablation study in patients with hepatic metastases from colorectal carcinoma.

MATERIALS AND METHODS: In 117 patients, 179 metachronous colorectal carcinoma hepatic metastases (0.9–9.6 cm in diameter) were treated with RF ablation by using 17-gauge internally cooled electrodes. Computed tomographic follow-up was performed every 4–6 months. Recurrent tumors were retreated when feasible. Time to new metastases and death for each patient and time to local recurrence for individual lesions were modeled with Kaplan-Meier analysis. Modeling determined the effect of number of metastases on the time to new metastases and death and effect of tumor size on local recurrence.

RESULTS: Estimated median survival was 36 months (95% CI; 28, 52 months). Estimated 1, 2, and 3-year survival rates were 93%, 69%, and 46%, respectively. Survival was not significantly related to number of metastases treated. In 77 (66%) of 117 patients, new metastases were observed at follow-up. Estimated median time until new metastases was 12 months (95% CI; 10, 18 months). Percentages of patients with no new metastases after initial treatment at 1 and 2 years were 49% and 35%, respectively. Time to new metastases was not significantly related to number of metastases. Seventy (39%) of 179 lesions developed local recurrence after treatment. Of these, 54 were observed by 6 months and 67 by 1 year. No local recurrence was observed after 18 months. Frequency and time to local recurrence were related to lesion size (P .001).

CONCLUSION: RF ablation is an effective method to treat hepatic metastases from colorectal carcinoma.

Index terms: Liver neoplasms, secondary, 761.33 • Liver neoplasms, therapy, 761.1269 • Radiofrequency (RF) ablation, 761.1269

Cancer J Sci Am 1999 Nov-Dec;5(6):356-61
Radiofrequency ablation: a minimally invasive technique with multiple applications.

Bilchik AJ, Rose DM, Allegra DP, Bostick PJ, Hsueh E, Morton DL

John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, California 90404, USA.

PURPOSE: Radiofrequency ablation (RFA) of soft tissue, which has recently been approved by the United States Food and Drug Administration, destroys tumor cells by delivering an electrical current through a 15-gauge needle. This study evaluated RFA for patients with hepatic malignancies considered unresectable because of their distribution, their number, and/or the presence of liver dysfunction. PATIENTS AND METHODS: Between November 1997 and February 1999, 50 patients with 132 unresectable hepatic metastases underwent RFA of tumors from 0.5 to 9 cm in diameter. There were 41 colorectal metastases in 22 patients, 13 hepatomas in seven patients, 37 neuroendocrine metastases in six patients, and 41 noncolorectal metastases in 15 patients. Real-time ultrasonography was used to guide RFA, and lesions were ablated by applying temperatures of approximately 100 degrees C for 8 minutes. Overlapping ablations were used for larger lesions. In patients with multiple lesions, RFA was performed simultaneously with cryosurgery, resection, and/or hepatic arterial infusion. RESULTS: RFA was undertaken percutaneously on an outpatient basis in 13 patients (25 lesions). The remaining patients underwent RFA via laparoscopy (21 patients; 58 lesions) or celiotomy (16 patients; 49 lesions); mean hospital stay was 1 and 5 days, respectively. RFA was the sole therapy in 28 patients and was additional therapy in 22 patients. At a median follow-up of 6 months, 27 patients were free of disease, 17 were alive with disease, and six had died of their disease (three colon, three melanoma). Three patients whose disease recurred at a prior RFA site underwent successful percutaneous RFA. Overall, there was a significant postoperative reduction in levels of carcinoembryonic antigen, alpha-fetoprotein, serotonin, and 5-hydroxyindoleacetic acid. Intraoperative ultrasonography identified unrecognized hepatic lesions in 12 of 37 patients (32%); these lesions were successfully ablated. When performed with cryosurgery, RFA reduced the morbidity of multiple freezes.

DISCUSSION: RFA is a safe and effective alternative for the ablation of unresectable hepatic malignancies and when used adjunctively can reduce the morbidity of cryosurgery. Percutaneous and laparoscopic RFA can be performed effectively with less than 24 hours of hospitalization. Intraoperative ultrasonography is essential for accurate staging.