Safety and feasibility of a novel externally cooled bronchoscopic radiofrequency ablation catheter for ablation of peripheral lung tumours: a first-inhuman dose escalation study

D. Steinfort*^a (Prof), P. Antippa^a (Prof), K. Rangamuwa^a (Dr), L. Irving^a (Prof), M. Christie^a (Dr), E. Chan^b (Prof), D. Tanaka^c (Mr), K. Yoneda^d (Prof), F. Herth^e (Prof), S. Raina^f (Dr)

^a The Royal Melbourne Hospital, Parkville, AUSTRALIA ; ^b Alfred Health, Melbourne, AUSTRALIA ; ^c EOLO Medical, Cupertino, UNITED STATES ; ^d UC Davis Health, Sacramento, UNITED STATES ; ^e University of Heidelberg, Heidelberg, GERMANY ; ^f Zidan Medical, Santa Clara, UNITED STATES

* daniel.steinfort@mh.org.au

Background

Surgical lobectomy remains preferred therapy for early-stage non-small cell lung cancer (NSCLC). Comorbidities and advanced age preclude resection in many patients. Radiofrequency ablation (RFA) is an effective modality for percutaneous ablation of NSCLC. We have developed a novel RFA Catheter with externally cooled electrode for ablation of pulmonary lesions.

Methods

Single arm treat-and-resect study. Biopsy-confirmed NSCLC. Procedures were performed under general anaesthesia with neuromuscular blockade. The RFA catheter was delivered bronchoscopically to peripheral parenchymal NSCLC lesions, guided by radial EBUS, and intra-procedural cone beam CT. Participants underwent lobectomy 7 days post-ablation. Pre-op CT chest and histologic examination of resected specimens established distribution/uniformity of ablation and efficacy of tumour ablation.

Results

Seven patients underwent RFA of NSCLC (median size 2.5cm, range 1.7-3.1cm) with sequential dose escalation. Uniform ablation was achieved within ablation zones, including tumour in all cases. Gravitydependent extension of ablation was frequently seen. Proportion of tumour ablated ranged from 8-72%, a dose-response (energy-ablation volume) relationship was observed.

Conclusion

Bronchoscopic RFA using externally cooled catheter is safe, feasible, and achieves uniform ablation within treatment zones at relatively low energy levels. Use of increased energy levels, and improved targeting/overlap of ablation zone to target lesion is expected to improve ablative efficacy. Future studies with a modified catheter are planned.

Disclosure of funding source(s):

This work was supported by Zidan Medical.