TOPLINE:

In a prospective development study, robot-assisted CT-guided cryoablation demonstrated 95% successful targeting of pulmonary metastases with minimal probe manipulation, achieving a median Euclidean targeting error of 6.1 mm and a 12-month local tumour progression-free survival of 97%.

METHODOLOGY:

• Researchers conducted a single-centre IDEAL stage 2a prospective study including 26 participants (median age, 62 years; 14 men) who underwent 30 robotic cryoablation procedures targeting 37 lung metastases using 54 cryoprobes between June 2023 and 2025.
• Procedures included high-frequency jet ventilation under general anaesthesia, following a triple-freeze protocol with ablation zone development monitored through intermittent spiral CT imaging.
• Participants received follow-up imaging at 6 weeks post-ablation, then at approximately 3 and 6 months, continuing every 6 months thereafter, with both CT and PET-CT reviewed to assess residual tumour and local tumour progression.
• Data collection occurred prospectively across four levels — participant, procedure, lesion, and probe. Primary outcomes included feasibility and safety, and secondary outcomes included technical performance and success.

TAKEAWAY:

• Robotic guidance achieved successful completion without conversion to freehand in 35 out of 37 tumours (95%).
• Pneumothorax requiring chest drain placement for 4 days with intermittent suction was the only major complication (grade 3). All other adverse events, including bleeding, hypoxia, fever, pleural effusion, and post-procedural pain, were grade 1-2 (67%).
• The median Euclidean targeting error on first insertion was 6.1 mm, with a lateral error of 4.2 mm, and the median total procedure time was 66.5 minutes.
• Technical success was achieved in 36 out of 37 tumours (97%). The median follow-up imaging duration for assessing local tumour progression was 193 days, and local tumour progression-free survival reached 100% at 6 months and 97% at 12 months.

IN PRACTICE:

"Robotic guidance offers particular advantages for cryoablation, enabling accurate and reproducible multiprobe configurations for conformal ice-ball formation with minimal manipulation," the authors wrote. "These findings suggest robotics may expand the treatable case spectrum and support a multicentre trial comparing robotic and freehand cryoablation," they concluded.

SOURCE:

This study was led by Nicos Fotiadis, Interventional Radiology, Royal Marsden Hospital, London, England. It was published online on February 05, 2026, in European Radiology.

LIMITATIONS:

This was a single-centre study with a relatively small cohort of 26 participants, which aligned with IDEAL stage 2a methodology but limited broader generalisability. The study primarily focused on subpleural metastases, potentially limiting applicability to central lesions.

DISCLOSURES:

This study received funding from the Royal College of Radiologists. One author reported consulting for Boston Scientific, and another reported consulting for Varian Medical Systems.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.