Feasibility and Safety of Percutaneous Radiofrequency, Microwave or Cryoablation for Unresectable Thoracic Malignancies in Close Proximity to Heart and Large Vessels

Background: Close proximity of a tumor to heart or large vessels is considered a relative
contraindication to percutaneous ablation. We reviewed our experience with the use of various ablation
modalities in such conditions.
Methods and Materials: A retrospective review of patients treated at our institution with percutaneous ablation
for unresctable lung or mediastinal malignancies (LMM) was performed, and patients with tumors located less
than 10 mm from large vessels or pericardium were identified. All ablations were performed under conscious
sedation and local anesthesia. The therapeutic outcomes were evaluated by contrast-enhanced CT after 1
month. Immediate and short term results are presented.
Results: Between June 2008 to January 2011 we treated with CT-guided percutaneous ablation 27 patients
(mean age 64 years) with lesions located within 10 mm from heart or large vessels. Overall, 13 metastases,
12 NSCLC, 1 thymoma, and 1 mesothelial sarcoma were treated with CT-guided radiofrequency ablation
(RFA, N=14), microwave ablation (MWA, N=7) and cryoablation (CA, N=6). In all cases, the procedure was
technically successful. No intra-procedural arrhythmia occurred. In two patients, an electrode penetrated in
the pericardium without consequences. Morbidity consisted of pneumothorax (n=7), and pleural effusions
(n=3). At 1-month follow-up, CT revealed complete necrosis in 22 cases and partial (from 70 to 90%) necrosis
in the 5 cases.
Conclusion: In our experience ablation of LMM in close proximity of hearth or large vessels appears effective
and associated with acceptable morbidity. Heat-sink effect did not preclude achievement of complete ablation
in the majority of those cases.