Abstract
Current therapies for metastatic lymph node (LN) are a major burden on health-care systems. Alternative such as percutaneous chemoablation using interstitial injection of ethanol or ethanol-ethiodol-drug(s) mixture (EEM) has been successfully applied to solid tumor ablation of the liver, adrenal glands, lymph nodes and others. However, EEM chemoablation efficacy on two most frequent clinical lymph node presentation, isolated or confluent, has not yet been determined. This study was designed to compare the therapeutic effects of CT-guided percutaneous EEM injection (PEEMI) on patients presenting with single or multiple confluent metastatic LN localizations from various carcinoma. Thirty six patients with metastatic LN carcinoma at various anatomical regions were enrolled from 2009 to 2010 over a nine month period. They were separated into two groups: group A includes 24 single isolated metastatic lymph nodes and group B includes 12 multiple and confluent nodes. The primary end point was the ablative efficacy of PEEMI. The intratumoral (IT) EEM distribution and the occurrence of reflux were recorded. Adjuvant systemic chemotherapy was administered after the procedure. Contrast-enhanced CT scans were performed during procedure and follow-up. Six patients were tested for Fluorodeoxyglucose (FDG) fixation before and after the procedure. For group A the EEM IT distribution-to-tumor ratio was 100% vs. 50% to 80% for group B (t = 11.5, p < 0.05). The reflux frequency was 80% for group A versus 30% for group B. For group A, a complete response (CR) rates of 45.8%, 70.8%, 91.7% and a partial response (PR) rates of 54.2%, 29.2%, 8.3% were obtained at 3, 6 and 12 months after therapy. Regarding group B, a CR rate of 0%, 0%, 0% and PR rate of 16.7%, 50%, 58.3% were observed at similar period of time. Standardized rate by direct method was performed and the CR rate (74.5%) for group A was higher than for group B. The tumor FDG uptake was lower 6 months after PEEMII compared with the preoperative images. Five patients presenting with concomitant lung metastasis, had a good local response-node size reduction on postoperative CT scanning, but no response on lung nodules that were progressing. No serious adverse events were observed. A few patients had mild pain during the procedure, which resolved with peritumor injection of local anesthetic. No needle tract seeding or infection occurred. CT-guided PEEMI treatment is a simple, fast and predictable procedure that has better effectiveness on single, well circumscribed metastatic lymph node than on multiple and confluent ones. Technical improvements are expected to bring better results on large nodes that should be confirmed on larger group of patients.