Needle based CLE in thoracic lymph nodes, a comparison with pathology.

The current minimal-invasive techniques for assessing mediastinal lymph nodes
have limitations, therefore surgical procedures are often indicated when a
diagnosis can not be established after an endoscopic procedure. Confocal laser
endomicroscopy is a novel imaging technique, that can be advanced trough a
biopsy needle and is capable of showing real-time images of tissues on a
microscopic level, during an EUS-FNA procedure. CLE is a novel technique and
the obtained images need to be defined and classified for different pulmonal
diseases that present with lymphadenopathy.

To identify and define characteristics of healthy lymph nodes and lymph nodes
involved in different pulmonal diseases (lungcancer and sarcoidosis)

This is an investigator-initiated, observational study in 20 patients. In 10
patients with NSCLC with suspected malignant lymphnodes and an indication for
EUS-FNA and 10 patients with suspected sarcoidosis stage I-II and an indication
for EUS-FNA.

A participating patient will not benefit from this study. However the results
of this study may benefit the diagnostic EUS-FNA procedure in mediastinal
lymph nodes and could make invasive biopsies and surgical procedures redundant.
Needle based CLE in combination with EUS has proved to be a safe, minimally
invasive imaging technique that in conjunction with conventional
endosonographic procedures can provide real-time information on a microscopic
level. There is little burden related to study participation: before the start
of the procedure a contrast-agent (fluorescein) will be administered
intravenously via the same entrance as the sedative-medication is provided. For
this reason patients won't undergo an extra venous puncture for study purposes.
We excluded patients with increased risk for allergic reactions to fluorescein
and therefore think that the risk of administering fluorescein is neglectable.
Furthermore two CLE measurements of lymph nodes will be conducted during the
EUS-FNA procedure, no additional risks are expected as no additonal tissue will
be removed and there is no risk of radiation. Estimated prolonged endoscopy
time for imaging is 5 minutes. The patient will not notice anything due to
propofol sedation. Adverse events are not expected , based on previous studies
where EUS-FNA combined with needle based CLE and the administration of
fluorescein is reported to be safe, easy to perform and little time consuming,
without adverse events. In conclusion we believe that the burden and risks
associated with the additional CLE measurements are low.