October 7, 2021—According to a study published in the October issue of the Journal of Bronchology and Interventional Pulmonology, bronchoscopy guided by cone beam CT (CBCT) and "enhanced" fluoroscopy can detect lung lesions around the biopsy 90% accuracy rate.
Researchers from Radboud University Medical Center in the Netherlands and Philips Healthcare conducted observational studies on more than 200 patients undergoing CBCT-guided navigational bronchoscopy, which included superimposing CBCT images on fluoroscopic imaging. Although the initial learning curve and imaging protocol need to be modified and customized based on surgery, the image-guided endobronchial lung biopsy method ultimately achieved 90% accuracy—and the effective radiation dose to patients and staff was much lower.
"Navigation bronchoscopy using CBCT and [enhanced fluoroscopy] imaging as the only technique for navigation and sampling is a (relatively) safe and accurate procedure for diagnosing small peripheral lung lesions," first author Roel Verhoeven of Radboud and colleagues Write.
CBCT can obtain 3D information during the process, which is a valuable benefit for positioning biopsy tools. The researchers said that this mode can also achieve what the researchers call "enhanced fluoroscopy", which is a technology that provides navigation paths and lesion locations as a superimposition of 2D fluoroscopy imaging.
They wrote: "With the combination of these functions, CBCT has the potential to carefully help guide endoscopists in different aspects of surgery."
Because this method of guiding the endobronchial diagnosis of challenging peripheral lung lesions relies on enhanced fluoroscopy and repeated CBCT scans for navigation and positioning confirmation, the researchers hypothesized the learning curve associated with this method—and the necessary protocols and System modification-will cause significant changes in the radiation exposure of patients and staff. Therefore, they attempted to conduct a prospective evaluation of 238 consecutive patients in Radboud between December 2017 and June 2020 to assess the accuracy of exposure and procedural diagnosis.
After applying the exclusion criteria, 100 cases can be used for radiation dose analysis, and a total of 248 lesions in 208 patients are included in the accuracy analysis. Of the 208 patients, 150 underwent primary CBCT and enhanced fluoroscopy; the main electromagnetic navigation method was used in the remaining 58 cases.
Researchers have observed significant improvements in dose area product (DAP) and accuracy over time. Reasons include gaining more experience with the method, fine-tuning the CBCT and fluoroscopy imaging protocol for the procedure, and reorganizing them The CBCT system was replaced by the Azurion Angiography System (Philips).
The reduction in radiation dose was mainly due to the implementation of a low-dose fluoroscopy program, which resulted in a drop in the average fluoroscopy DAP from 19 Gy·cm2 to 2.2 Gy·cm2. Although the average total fluoroscopy time increased from 9.9 minutes to an average of 15.6 minutes, the dose reduction was still achieved.
"Considering the accuracy of CBCT-guided navigational bronchoscopy, the patient's procedural radiation burden when related to other procedures, and the related costs of some additional navigation guidance modes, it is necessary to separately evaluate whether there are still multiple navigation guidance modes worthwhile," the author Write. "According to our experience, compared with other non-real-time navigation technologies (such as [electromagnetic navigation]), the added value of CBCT and [enhanced fluoroscopy] is the largest in terms of lesions that require more detailed positioning."