Laser Ablation of Lung Metastases: Technique and Results after 21 Treatments

Abstract

Summary A thin-caliber applicator system was developed for laser ablation of lung metastases. Feasibility of lung metastases ablation as well as the complication rate and clinical results were evaluated. We calibrated the miniaturized applicator system in non-perfused bovine liver for maximum energy supply and necessary flow of the cooling saline solution in reference to a commercially available system (Power laser applicator kit, Somatex, Teltow, Germany). The size of heat coagulation in bovine liver was 24 ± 2 ml with the miniaturized system in comparison to a size of 29 ± 7 ml for the existing applicator. 15 W were applied for 20 min and a saline flow of 40 ml/h with the miniaturized applicator and 30 W, 20 min, 60 ml/min with the standard applicator. 21 patients with 32 lung metastases were then treated and the results as well as minor and major complications were evaluated. Ablation was technically successful in all but 2 patients. 14 patients were considered to be effectively treated. Their metastases showed a marked reduction of volume. Volume reduction took several months to develop. Successful treatment had either a ground-glass appearance of the treated site or a cystic defect as a morphological correlate. We conclude that successful ablation of lung metastases is possible with a miniaturized applicator.