Rapid on-site evaluation (ROSE) vs. randomly collected samples from mediastinal and abdominal lymph nodes obtained by endoscopic ultrasound-guided fine-needle-aspiration

Endoscopic ultrasound (EUS) is a widely used, minimally invasive and safe
method for imaging mediastinal and abdominal lymph nodes. A major advantage of
EUS is that interventions such as fine needle aspiration (FNA) are possible
during the procedure. FNA adds the ability to take lymph node samples and to
reach a definitive diagnosis based on cytology, histological tissue samples or
a combination of both. FNA has changed EUS from a highly subjective imaging
modality in a more objective diagnostic procedure. EUS-FNA is used for
diagnosing and staging abdominal and mediastinal tumors and benign diseases
such as sarcoidosis and reactive lymphadenopathy. The high sensitivity, high
accuracy and low complication risk has led to an increasing number of
gastroenterologists performing EUS-FNA in daily practice.
There is an ever present ambition to optimize the diagnostic yield of EUS-FNA,
a representative sample of the contents of the lymph node is essential for
making a diagnosis. Therefore, many studies have been conducted with the
emphasis on increasing the yield of diagnostic EUS-FNA through the optimization
of different aspects of the process. One aspect that has been investigated by
several studies is the addition of direct on-site evaluation, although these
were mainly retrospective studies. Several approaches have been used to assess
the benefit of either a cytopathologist or a cyto-analyst spot. The idea is
that having a cyto-analyst on site is useful to give feedback and advice to the
endosonografist if necessary. It is thought that this reduces the number of
non-diagnostic procedures. However, study results are contradictory.

The goal is to investigate the added value of having a cytotechnician on-site
while performing EUS-FNA of a lymph node.

This is a multi-center, prospective, single-blinded, randomized controlled
trial. In the random sample group, the endosonographer is blinded to the
evaluation of the cytotechnician. The cytopathologist that later re-analyzes
the samples (in the context of the study, not daily practice) is blinded to the
evaluation of the cytotechnician and to the diagnostic group of the patients,
which means that the samples will be evaluated sequentially without any further
information on how many needle passes were performed. The results of the
EUS-FNA will be compared to the final diagnosis. The definitive diagnosis is
based on histology of the lymph nodes or clinical follow-up of at least 6
months or until death.

EUS-FNA is a safe procedure. Complications occur in 0-1%. Although
hypothetically an increased number of needle passes could increase the risk of
complications, no such correlation has ever been established. Patients are
sedated during the EUS-FNA and therefore do not experience more discomfort in
either group. Standard of care is provided. Post-procedural treatment does not
differ between the two groups. There is no direct benefit for patients
participating in this trial.