Lung cancer patients with relatively small nodules who cannot or will not undergo surgery or radiotherapy can be successfully treated with targeted transbronchial microwave ablation, indicate results from a U.K.-led preliminary trial.
The NAVABLATE study included 30 patients from the U.K. and Hong Kong who had malignant lung nodules no more than 30 mm in diameter, who underwent transbronchial microwave ablation and were followed up one month later.
On the day, the technique was performed successfully in all 30 patients, while follow-up imaging at one month suggested that the ablation had been satisfactory in every case, with no repeat procedures necessary.
It was also associated with a “low rate of device-related adverse events and no serious adverse events,” said lead author Kevin Lau, Barts Thorax Centre, St. Bartholomew’s Hospital, Barts Health NHS Trust, London.
Consequently, transbronchial microwave ablation can be considered “an alternative treatment modality for patients with primary and metastatic malignant lung nodules … who decline or are ineligible” for surgery and radiotherapy.
The research was presented at the European Respiratory Society International Congress (ERS) 2021 on September 5.
‘Encouraging’ results
Professor Stefano Elia, head of the European Respiratory Society’s Assembly on Thoracic Surgery and Transplantation, told this news organization that the results “are encouraging.”
However, the patient numbers are “very low, so it is difficult to draw value conclusions,” and he would like to have seen more detailed characterization of the patients’ tumors.
Prof. Elia, from the University of Rome Tor Vergata, added that transbronchial microwave ablation should, in line with the study’s inclusion criteria, “probably be reserved” for lung cancer patients “who are unfit for or refuse surgery or alternative treatment strategies.”
He added that “prospective, randomized trials are warranted to see if the technique is feasible, safe and indicated” in these patients, and the potential cost of performing it needs to be specified.
Study details
Presenting the study, Mr. Lau explained that NAVABLATE was a prospective, multicenter study that enrolled patients with a confirmed malignant lung nodule ≤30 mm that did not abut the pleura, fissure, or critical structures.
In addition, the patients had declined or were not eligible for both surgery and stereotactic body radiotherapy.
They underwent transbronchial microwave ablation with the Emprint ablation catheter (Medtronic) in a hybrid theatre while undergoing cone-beam computed tomography. Only one nodule was ablated if the patients had more than one.
The team recruited 30 patients at two centres in the U.K. and Hong Kong, who had a mean age of 68.4 years and of whom 40% were female. The majority (66.7%) were prior or current tobacco users.
Primary lung cancer was the diagnosis in 20 patients, while 10 had oligometastatic disease, and the median nodule size was 12.5 mm. Thirty percent of patients had previously undergone lobectomy and 16.7% wedge resection.
Thirty-nine ablations were performed in the 30 patients, with 22 having a single ablation. Two ablations were performed in seven patients, while one had three ablations.
The most common ablation times were 10 minutes, in 21 procedures, and 7 minutes, in eight procedures, and the average total bronchoscopy time was 127 minutes.