Cone-beam CT allows quicker lung ablation than CT

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A study from Institut Bergoniè (Bordeaux, France), in collaboration with Università Campus Bio-Medico di Roma (Rome, Italy), that set out to compare the duration of targeting and positioning of radiofrequency ablation electrode on lung tumours using two different modalities finds that cone-beam CT is faster than CT.

“Irrespective of lesion size, cone-beam CT allows faster lung radiofrequency ablation than CT,” Roberto Luigi Cazzato, Rome, Italy, told delegates at the European Congress of Radiology (ECR, 4–8 March, Vienna, Austria).

The investigators prospectively enrolled and randomised patients referred for lung radiofrequency ablation due to primary or metastatic lung tumours to receive cone-beam CT- or CT-guided ablation. They also stratified patients into three groups based on lesions size. Group 1 consisted of patients with lesions <10mm in diameter; group 2 had patients with 10–20mm lesions and patients in group 3 had lesions ≥20mm. The researchers registered and compared the time needed to target and place the radiofrequency ablation electrode within the lesion in all groups. They also investigated the instances of electrode repositioning, the time needed for it, complications with the ablation procedure and local recurrence after ablation.

Forty tumours were treated in 27 patients (19 male, age 67.25±9.13 years). Thirty radiofrequency ablation sessions were performed (16 under cone-beam CT-guidance and 14 under CT guidance).

“Our results showed that the time required to target and place the radiofrequency ablation electrode was significantly shortened when cone-beam CT-guidance was applied, irrespective of lesions size (p < 0.05). Electrode repositioning occurred while treating 6/18 (33.3%) tumours under cone-beam CT-guidance and 9/22 (40.9%) tumours under CT-guidance. Electrode repositioning took longer under CT guidance across all lesion sizes,” Cazzato said.

In terms of complications, pneumothorax occurred in 6/14 (42.8 %) radiofrequency ablation sessions conducted under CT guidance and in 6/16 (37.5 %) conducted under cone-beam CT guidance. In the end, across the entire follow-up, three (3/19, 15.8%) recurrences were noted in the group of tumours receiving CT-guided ablation and two (2/17, 11.7%) recurrences occurred among those receiving cone beam CT-guided ablation.

“The study, conducted under the supervision of Jean Palussière, chief, Department of Radiology, Institut Bergoniè, highlights that in institutions where interventional radiologists have limited access to CT scanners, cone-beam CT installed in the angiosuite represents a valuable option to perform lung ablation. In fact, the safety of the procedure under cone-beam CT guidance is comparable to that available under traditional CT guidance. Technically speaking, in our experience, the constant control of the electrode granted by the navigation system available on the cone-beam CT machine was straightforward. It is possible that organs other than lung may benefit from such a cone-beam CT-guided approach. For example, in the particular setting of liver tumours, a certain advantage of cone-beam CT could be the possibility to perform ablation and embolization for large-sized lesions in the same session,” Cazzato said.