Christine Weigel, Abstract Co-Author: Nothing to Disclose

Sebastian Schuchmann PhD, Presenter: Nothing to Disclose

Michael Kirsch MD, Abstract Co-Author: Nothing to Disclose

Norbert Hosten MD, Abstract Co-Author: Nothing to Disclose

To determine results of CT-guided laser ablation of pulmonary metastases regarding technical success, complications, technique effectiveness.

Laser ablation of 45 pulmonary metastases was performed under conscious sedation in 31 patients over a 4-year period. Primaries were colorectal (14), melanoma (5), renal cell carcinoma (5), and others. Largest diameter of metastases ranged from 1.0 to 7.7 cm (mean 2.8 cm). A Nd-Yag laser (Dornier, Germany) was used with diffusor tip laser fibers with 2 or 3 cm domes (Trumpf, Germany). A 5.5 French applicator (Monocath, Trumpf, Germany) cooled by saline was used for introduction of laser fibers. Up to 4 laser fibers were powered simultaneously in 1 metastasis. CT fluoroscopy was used for image guidance (GE HiSpeed). Pulmonary CT was performed before, and at days 2, 90, 180 etc. after therapy. Follow up was available for 35 metastases (1 to 45 months, mean 8.4 months). 5 metastases were removed surgically because of insufficient ablation. 5 metastases were lost to follow-up due to patient’s death from underlying disease.

Technical success was achieved in 40/45 metastases. In 5, ablation failed due to gross pneumothorax (3) or failed catheter placement due to excessive lung movements in the basal recess (2). 17 metastases showed complete regression on follow-up and were considered R0 while 14 showed partial ablation (R1). 4 metastases were basically unchanged with only minimal central necrosis after laser ablation (R2). In 5, no follow-up was available. – Imaging findings were initially progressive in 10 metastases independent from technique effectiveness. Loss of previous contrast enhancement in a nodule was an early proof of technique effectiveness. In 5 metastases a large thick-walled cyst appeared at the site of ablation. Technique effectiveness did not require intratumoral position of laser fibers probably due to transmission of laser energy through aerated lung.

Laser ablation of pulmonary metastases had the best results in middle-sized (2.5 – 4.0 cm diameter) metastases. Lesions located in the core of the lung were better accessible than peripheral nodules. Uncontrollable pleural pain was a problem in the latter.

Weigel, C, Schuchmann, S, Kirsch, M, Hosten, N, Percutaneous Laser Ablation of Pulmonary Metastases Performed during CT Fluoroscopy under Conscious Sedation: Technical Success, Complications, and Technique Effectiveness during a 4-year Period.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4405738.html