nCLE-guided bronchoscopy for peripheral lung cancer diagnosis; a Randomized Controlled Trial

Summary description of the study

Tumors in the lung can have various causes and can be either benign or malignant. X-rays or CT scans often cannot definitively determine what type of lung tumor it is. Therefore, in most cases, a bronchoscopy is necessary, where tissue is obtained from the tumor using needles, forceps, or cryoprobes, allowing for identification of the tumor type. However, the difficulty with this examination can sometimes be that the tumor cannot be accurately located, and the tissue samples are therefore not taken from the correct, optimal site. New techniques are continuously being introduced to help the physician find the optimal position for tissue sampling. One such technique is confocal laser endomicroscopy (CE-certified), which allows for direct visualization of tumor cells. This can give the physician more confidence that they have found the optimal position for tissue sampling. The physician inserts a needle into the tumor, which contains a CLE probe. After visualizing the tumor cells, the CLE probe is removed from the needle, and the physician can then directly obtain the tumor cells with the needle. Additionally, tissue samples are also taken using forceps or the cryoprobe at the examiner's discretion. This is not study-related but clinically necessary, as the goal is to obtain as much tissue as possible for diagnosis. Currently, it is not known whether the use of such a CLE probe truly increases diagnostic accuracy. This question will be addressed in this study.

(BASEC)

Intervention under investigation

As part of standard care, a bronchoscopy will be performed through the trachea. A sedative will be administered via an infusion in the arm so that patients do not notice anything during the examination.

For the study, we will apply the CLE technique as an adjunct to bronchoscopy in 50% of the participants.

We will form two groups for this study:

• Group 1: Participants in this group will undergo regular bronchoscopy without additional CLE technique.

• Group 2: Participants in this group will undergo the CLE technique in addition to regular bronchoscopy.

The two examination groups will be selected randomly. Before the bronchoscopy begins, they will not know which group they have been assigned to.

The bronchoscopy is performed for medical reasons, not study-related. Patients will be informed separately about the bronchoscopy and its risks. The bronchoscopy will proceed as follows: While they are asleep, the physician will locate the lung tumor as usual and insert a needle into it for a tissue sample.

The only difference from the "standard treatment" is that during the bronchoscopy, a CLE probe will be temporarily inserted into the tumor to visualize the tumor cells. Fluorescein will be injected into the vein so that the tumor cells can be seen using the CLE probe. This will extend the bronchoscopy by about 10 minutes. Otherwise, the bronchoscopy and the entire treatment do not differ from the clinical standard.

After the bronchoscopy, patients will remain in the recovery room for about 1.5 hours, which corresponds to the standard protocol after a normal bronchoscopy. Patients do not need to come for an additional hospital visit.

(BASEC)

Disease under investigation

Peripheral lung cancer

(BASEC)

Sponsor

University Hospital Basel

(BASEC)

Name of the authorising ethics committee (for multicentre studies, only the lead committee)

Ethics Committee northwest/central Switzerland EKNZ

(BASEC)

Date of authorisation

24.06.2025

(BASEC)

Results of the trial