Pilot study on the use of fluorescence imaging of lymph nodes during laparoscopic pelvic sentinel node dissection for prostate cancer, using indocyanine green

Microscopic nodal metastases occur in 3-50% of men with presumed localized
prostate cancer. In high risk patients, (laparoscopic) sentinel lymph node
(SLN) dissection shows high reliability in staging of prostate cancer .
Intraoperative detection of sentinel nodes, however, is currently performed
using a gamma probe (radioisotope guided). The high tissue penetration makes it
difficult to localize a radioactive lymph node, as the signal coming from the
injection site will also be detected. A way to circumvent this is to measure
under different angles and upgrade the gamma probe to a gamma camera. However,
despite improvements in collimator technology, gamma camera detection always
implies the use of a TV-monitor presenting the radionuclide image separate from
the operative field image. In addition, it requires a dedicated camera operator
that rotates the camera around the patient during surgery. Fluorescence imaging
of SLN could potentially supplement this approach allowing for direct visual
presentation of the SLN, using a laparoscopic camera (will be made available by
Strorz). Here the low tissue penetration of the fluorescent dye limits the
amount of background signal and thus improves the specificity. The fluorescent
dye Indocyanine green (ICG) was shown to be useful for the intraoperative
detection of sentinel nodes in a variety of tumors. A PTC (and ICG drug study)
for the use of ICG in CRC-lymphatic imaging was also recently approved at the
NKI-AVL. We, hypothesize that the use of ICG imaging could also enhance the
practicality of prostatic node dissection. In preclinical studies in mice with
spontaneous prostate carcinoma*s (TRAMP-model) we have extensively tested this
approach and compared it to the conventional radioisotope guided approach (both
via intratumoral/intraprostatic injection). Within these preclinical models,
the radioisotope NanoColl was used to plan the surgical procedure based on
SPECT/CT and ICG proved to be a perfect addition to guide the surgical
resection. Furthermore, a good correlation between fluorescent and *hot* nodes
was observed. These preclinical studies also found a significant increase in
detection sensitivity for ICG compared to the conventional blue dye (Patent
blue): detection was possible up to 4h post ICG injection.

The potential use of intraoperative, ICG based sentinel node identification,
fluorescence imaging of LN*s during lymphadenectomy for prostate cancer

Non-randomised, open pilot study.

Preoperative transrectal ultrasound guided intraprostatic injection of a
cocktail of ICG and NanoColl

Other than intraoperative injection and tracking of ICG, this study will not
result in any procedures different from the standard procedures. The
ICG-injection will be given during the standard NanoColl sentinel node
procedure of the prostate cancer. Operation time may be extended by 10-20 min.
due to the imaging time. It may, however, be anticipated that the value of an
improved and more adequate lymphadenectomy could have a major impact in the
improvement of staging and postoperative outcome
In rare cases (< 1/10.000) nausea, urticaria and anaphylactic reactions have
been reported. Because of the proposed exclusion criteria, these numbers will
be lower within this study.