Sentinel node biopsy for bladder cancer using the hybrid tracer

Sentinel node (SN) biopsy for staging was initially introduced in breast
cancer, melanoma patients and penile cancer. A SN is defined as a first primary
draining LN from the tumor (organ), without any interception of another LN in
the lymph tract. Multiple SNs can be present in one patient. The location of
the SN can be depicted on lymphoscintigraphy and SPECT/CT following an
injection of a radiocolloid (99mTc-nanocolloid) that is then transported
through the lymphatic system into the SN.
Provided that the spread of tumor cells is in a orderly fashion, compared to
the ePLND, SN biopsy can be restricted to resection of the SNs only, and as
such is able to determine the regionally lymphatic status in clinically tumor
negative patients in a minimally invasive manner. For bladder cancer different
authors described the SN procedure using different tracers . The results of
these studies show that the SN procedure is accurate and is able to locate the
SNs outside the ePLND.
The purpose of this trial is to evaluate the accuracy of the SN biopsy in
localization of tumor positive (sentinel) lymph nodes. For this purpose we will
use the hybrid tracer ICG-99mTc-nanocolloid. This tracer is both radioactive
and fluorescent allowing preoperative lymphoscintigraphy and single photon
emission computed tomography (SPECT) combined with computed tomography (CT)
(SPECT/CT) imaging for preoperative and intraoperative localization of the SN
with a radioactive signal and optically with fluorescence.

Evaluation of the accuracy of the sentinel node procedure in bladder cancer
patients.

Prospective, interventional study

On the day before surgery (approximately 18hours) patients will receive 4-6
transurethral injections with a total of 2mL hybrid tracer
ICG-99mTc-nanocolloid (240MBq) around the tumor (in case of a solitary lesion)
or divided over the bladder (in case of multiple tumors). In both cases the
hybrid tracer is injected into the detrusor muscle of the bladder under
cystoscopy guidance using an endoscopic needle. After the injection
lymphoscintigraphy will be performed at 15 min and 2hours, followed by SPECT/CT
imaging at 2 hours.
Intraoperatively sentinel nodes will be identified via combined radio- and
fluorescence guidance. For radioguidance, a (laparoscopic) gamma probe will be
used. Fluorescence imaging during the operation will be performed using a
fluorescence camera for open surgery or for laparoscopic surgery. Additionally,
during robot-assisted procedures, the da Vinci SI integrated fluorescence
camera (Firefly) will be used.
The declipseSPECT navigation system will be used to locate the sentinel nodes
intraoperatively.

The total dose of radioactivity lies within the limits that are indicated by
the Gezondheidsraad, in the *Normen voor de toediening van radioactieve stoffen
aan vrijwilligers*.
Rarely, nausea, urticaria and anaphylactic reactions (<1/10,000) have been
reported after intravenous injection of ICG. Because of the proposed exclusion
criteria and the intravesical injection, these numbers may be assumed to be
lower within this study.
The patients remain at risk for all complications related to an extended pelvic
lymph node dissection such as: lymphocele, hematoma and ureteral lesions.