Radiofrequency ablation of lung metastases close to large vessels during vascular occlusion: Preliminary experience

Purpose: To report an initial prospective evaluation of the technical feasibility, efficacy, and safety of combining percutaneous temporary balloon occlusion (PBO) of a large pulmonary artery adjacent to a metastatic lung tumor treated with percutaneous radiofrequency (RF) ablation. Materials and Methods: In six patients, lung RF ablation with a multitined, expandable electrode with simultaneous PBO via femoral access was attempted with the use of digital angiography and multidetector computed tomography (CT). Follow-up imaging was obtained immediately after treatment, at 1-2 days, and at 2, 6, 9, and 12 months; positron emission tomography/CT was performed at 4 months. Results: Metastases targeted measured 17-37 mm (22 ± 8) and were in contact with a pulmonary artery 3-5 mm. Temporary occlusion of the pulmonary arterial branch in contact with the tumor was technically possible in five of six patients. Postablation CT scans obtained within 2 days of the procedure showed ablation zones measuring 37-57 mm (47 ± 8) in their shortest diameter. Three patients developed lung infarction within 1 month after RF ablation, and two had to be readmitted. At 3 months after the procedure, four patients had persistent occlusion of the balloon-occluded vessel. No uptake was demonstrated 4 months after ablation; at 12 months, all tumors showed complete ablation on CT. Conclusions: RF ablation of lung tumors with PBO is a feasible technique, but it induces atelectasia and long-lasting vascular occlusion responsible for a high rate of readmission. The results of this small study warrant careful further exploration of the benefits of the technique, compared with RF ablation without PBO or other methods of ablative therapy.