Pulmonary and Mediastinal Lesions Clinical Trial
Official title:
Feasibility of Confocal Laser Microscopy CLM in the Computed Tomography-guided Needle Biopsy of Pulmonary and Mediastinal Lesions
The hypothesis of this proposal is that needle confocal laser microscopy (nCLM) may improve the yield of trans thoracic needle biopsy (TTNB) of lung or mediastinal lesions by differentiating between viable and necrotic tissue. This may reduce the number of biopsy attempts and eventually the complication rate of the procedure.
CT guided needle biopsy (TTNB - trans thoracic needle biopsy ) of pulmonary lesions is a
well established diagnosis technique in pulmonology. It is most suitable for peripheral lung
lesions with a diameter greater than 2 cm and for the diagnosis of a mediastinal mass. In
these situations the diagnosis yield may reach up to 90% . However in smaller or "non
homogenous" lesions (as to CT imaging) the yield lowers to only 60% .As usually there is no
rapid onsite specimen pathologic examination (ROSE) a number of attempts (passages) are
performed in order to receive a good quality sample. The complication rate of TTNB
(pneumothorax or bleeding) is relatively high ( up to 15% and 5% respectively). Necrosis is
a common feature of rapid growing tumors and may significantly impair the histopathological
diagnosis and thus lowering the TTNB yield. Optimization of the needle position into a
viable tissue area of the lesion is imperative as to improve the yield of the TTNB
technique.
CLM is an emergent technique in which a low power laser excites the autofluorescence or the
induced fluorescence (by intravenous. administration) of tissues. . CLM is capable of to
provide the examiner with near histopathological quality tissue imaging serving as an
"optical biopsy". The technique is well established in dermatology and gastroenterology (via
endoscopes) and serves in distinguishing cellular abnormalities in inflammatory,
premalignant and malignant disorders. Recently pulmonary applications were described
allowing for alveolar real time vision (alveoscopy) . While used through the working channel
of different endoscopes it is named probe CLE ( probe confocal laser endomicroscopy).
Needle based confocal laser endomicroscopy (nCLE) was studied in the diagnostic of
pancreatic masses and celiac/mediastinal lymph nodes .A probe CLE was introduced through a
19 G needle biopsy by endoscopic guidance into the lesion. Imaging started following
intravenous administration of fluorescein .Preliminary results showed good quality of
imaging and also a remarkable positive predictive value of pictures details in normal versus
disease tissue .
The CLM probe has a diameter of 0,85 mm and may be introduced through a 19 G trans thoracic
biopsy needle by replacing the stylet. Its field of view is of 320 µm , lateral resolution
3,5 µm , depth of 50 µm and length of 4 m. the TTNB will be performed according to the
standard protocol at the Interventional Radiology Department at Sheba, following the
intravenous administration of fluorescein. This protocol is described further .
After receiving consent, the patient lies on the CT table and the skin over the chest lesion
is cleaned and draped in the usual sterile fashion. Local anesthesia is delivered with
Lidocaine 2% to the skin and pleura and a 19G introducer needle is advanced to the lesion
border under CT vision. Via this introducer a 20G core biopsy needle is advanced and 3-6
biopsies are performed. Following the procedure another CT scan is performed to evaluate for
any immediate complications and the patient is transferred to a recovery room for 2 hours
observation. Before discharge a chest radiography is performed to evaluate for possible
pneumothorax or bleeding.
The use of fluorescein in pulmonary medicine was described in CLM through bronchoscope.The
protocol consists of the injection of 10 ml of 0,25% of sodium fluorescein solution through
a venous catheter and immediate rinsing with 10 ml saline solution 0,9%. This differs from
ophthalmologic or gastroenterologic protocols as using a diluted solution. Imaging may start
1 minute following the injection and last up to 10 minutes. We expect lower side effects
from fluorescein use as those described in retinal angiography. Fluorescein stains the
microvasculature, extracellular matrix and cytoplasmic component (but not cell nuclei) of
epithelium and diffuses across capillaries into extravascular spaces. CLM with fluorescein
can be used to diagnose neoplasia by presenting abnormal vessels (increased size and
arborization) . Increased leakage owing to neovascularization may also be diagnosed. On site
rapid cytological examination (ROSE) will be the standard for biopsy quality.
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Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Diagnostic