Spectroscopy in lymph nodes during Endoscopisch Ultrasound-Fine Needle Aspiration (EUS-FNA) procedure in patients with lung cancer

Lung cancer is the second most common cancer in men and women, and is the
leading cause of cancer related death. In industrialized countries it kills
more patients than breast, colorectal and prostate cancer combined. Treatment
and prognosis are depended on stage. During lung cancer staging analysis,
information about the possibility of metastasis in mediastinal lymph nodes is
very important. Recent development makes it possible to examine mediastinal
lymph nodes by Endoscopisch Ultrasound-Fine Needle Aspiration (EUS-FNA)
procedure. Unfortunately, ultrasound sensitivity to detect positive lymphnodes
is poor, and therefore cytology must always be obtained. Transoesophageal
ultrasound fine needle aspiration will take place to obtain tissue, which will
send to the pathologist for further analysis.
Although this take place under echographic vision, it is not possible to know
which part of a lymph node has the highest chance to obtain a positive result.
To reduce the chance of false negative results a lymph nodes must be aspirated
many times. This makes an EUS procedure long and expensive. Even when a
pathologist examin the samples, right after the procedure, false negative
result are possible. After a negative EUS procedure, a mediastinoscopy must be
carry out, is still nowadays concensus. This procedure is must more invasive,
and the risk of complication is higher.

Development of a new technics to improve the diagnostic value of an EUS
procedure in combination with reducing the amount of biopsies.

The method to measure optical properties in vivo with the use of diffuse
reflectance measurements has been documented in literature. As light source, we
use a xenonlamp and for the detection of reflected light a 2-canal
spectrograph. The transport of light from the light source to the tissue and
reflected light back to the spectrograph is by a 5 meters length glass fibre.
Because of this long glass fibre length, the measurement equipment can
positioned at a save distance of the EUS-FNA equipment.
During Endoscopic Ultrasound Fine Needle Aspiration (EUS-FNA) procedure a
gastroscope is introduced in the oesophagus. With help from an echo located at
the distal end of the scope, suspected lymph nodes are detected and a standard
EUS-FNA needle is conducted to the mediastinal lymph nodes. The sterile biopsy
needle is positioned in a mediastinal lymph node and the working guide wire,
which is in the needle core, is removed. A sterile fiberoptic probe is inserted
through the now empty working cannel of the biopsy needle in the lymph node and
a measurement is performed. After the fiberoptic probe is removed from the
needle, cytological tissue can be obtained. To prevent risk of ent-metastasis
or diagnostic misleading, measurements take place by standard EUS-FNA
procedure. This implies measurements starting in lymph nodes N3 then N2 and
finally N1.
The cytological result will be correlated to the spectral results, which are
collected with the sterile fiberoptic probe.

A file with the required records is present and available for examination.
The following security supplies
a) Optical
The light intensity of the optical fibres is less than 200 µWatt. This is far
below the threshold for thermal damage of the patients lungtissue and the eyes
of the supportive staff. Other damage have not been confessed in this golf
length area.
b) Hygiene
The disposables optical fibers are made especially for this research and
supplied sterile.