Feasibility and safety of percutaneous computed tomography guided radiofrequency ablation of lymph nodes in oligometastatic patients: a single center's experience

Abstract

Objectives: To retrospectively evaluate feasibility and safety of CT-guided percutaneous radiofrequency ablation (RFA) of metastatic lymph nodes (LN) in terms of achieving local tumor control.

Methods: Institutional database research identified 16 patients with 24 metastatic LNs who underwent percutaneous CT-guided radiofrequency ablation. Mean patient age was 66.6 ± 15.70 years (range 40-87) and male/female ratio was 8/8. Contrast-enhanced CT or MRI was used for post-ablation follow-up. Patient and tumor characteristics and RFA technique were evaluated. Technical and clinical success on per tumor and per patient basis as well as complication rates were recorded.

Results: Mean size of the treated nodes was 1.78 ± 0.83 cm. The mean number of tumors per patient was 1.5 ± 0.63. The mean procedure time was 56.29 ± 24.27 min including local anesthesia, electrode(s) placement, ablation and post-procedural CT evaluation. Median length of hospital stay was 1.13 ± 0.34 days. On a per lesion basis, the overall complete response post-ablation according to the mRECIST criteria applied was 75% (18/24) of evaluable tumors. Repeat treatment of an index tumor was performed on two patients (three lesions) with complete response achieved in 87.5% (21/24) of evaluable tumors following a second RFA. On a per patient basis, disease progression was noted in 10/16 patients at a mean of 13.9 ± 6.03 months post the ablation procedure.

Conclusion: CT-guided percutaneous RFA for oligometastatic LNs is a safe and feasible therapy.

Advances in knowledge: With this percutaneous therapeutic option, metastatic LNs can be eradicated with a very low complication rate.

Figure 1.

A 50-year-old male patient with hepatocellular carcinoma and metastatic lymph node: A: CT axial scan illustrates the lymph node along the right mammary vessels. B: Patient underwent CT-guided percutaneous RFA; the active tip of the electrode was placed inside the lymph node. C: MRI 6 months post-RFA shows no contrast enhancement of the lymph node. RFA, radiofrequency ablation.

Figure 2.

A 61-year-old male patient with a solitary metastatic lymph node in para-aortic location post nephrectomy for renal cell carcinoma (white circle). B: Patient underwent CT-guided percutaneous RFA. Hydrodissection was performed with dextrose 5% mixed to contrast medium. C: CT scan post-i.v. contrast medium injection shows no contrast enhancement of the lymph node. i.v., intravenous; RFA, radiofrequencyablation.

Figure 3.

A PET scan of a 73-year-old female patient with colorectal cancer showing avidity in a metastatic lymph node in para-aortic location (black circle). B: Patient underwent CT-guided percutaneous RFA. C: MRI 3 months post-RFA shows no contrast enhancement (white circle) of the lymph node. PET, positron emissiontomography; RFA, radiofrequency ablation.