SENSEI® system for detecting sentinel lymph nodes in cervical cancer

Rationale: We evaluate the technical feasibility and usability of the SENSEI® laparoscopic tethered gamma probe system for detection of sentinel lymph nodes (SLNs) in patients with early-stage cervical cancer. The rigid laparoscopic gamma probe currently used for robot-assisted laparoscopic surgeries in cervical cancer has limited manoeuvrability and control which restricts nodal identification.

Device name: SENSEI® laparoscopic tethered gamma probe system, LightPoint Ltd. The SENSEI® system comprises of a laparoscopic tethered gamma probe connected to a main powered control unit.
Product Regulatory Status: CE-marked medical device for sentinel lymph node biopsy in prostate, endometrial and cervical cancer.

Objective: To examine the safety and feasibility of the SENSEI® laparoscopic tethered gamma probe system for sentinel lymph node biopsy (SLNB) with 99mTc-nanocolloid in patients with early-stage cervical cancer.

Study design: Investigator initiated feasibility study, single arm.

Study population: Women with early-stage cervical cancer (FIGO stage IA – IB2 or IIA1) scheduled for primary surgical treatment including SLNB who have no contraindications for use of 99mTc-nanocolloid.

Sample size: 10 patients (feasibility study).

Study duration: An estimated recruitment period of six months.

Intervention: SLNB with use of SENSEI® laparoscopic tethered gamma probe system for detection of 99mTc-nanocolloid.

Study procedures: The preoperative preparations (e.g. injecting 99mTc-nanocolloid and performing a SPECT-CT one day before surgery) will proceed according to the current standard protocol. On the day of surgery, the SLNB will start with the use of the SENSEI® laparoscopic tethered gamma probe system (after calibration with a Cobalt-57 sealed source at the OR). The SLN detection and anatomical location with the investigational probe is reported. Subsequently, the conventional rigid gamma probe (Europrobe 3 Coelioscopique, Euromedical Instruments, Le Chesnay, France) will be used to check the correct identification of SLNs (in vivo). The SLNs will then be excised and radioactivity is also checked ex vivo with both probes (according to the current standard of care). The rest of the robot-assisted procedure will be performed according to the standard institutional protocols, including the frozen section examination of the SLNs and a bilateral pelvic lymph node dissection.

Main study parameters/endpoints: The main study parameter is the SLN detection rate (defined as the detection of at least one SLN in each patient) with the SENSEI® laparoscopic tethered gamma probe. Secondary endpoints include the duration of the SLNB, number of SLNs detected, and intraoperative adverse events of the SENSEI® system in comparison to the conventional rigid laparoscopic gamma probe. Also, the overall ease of use of the SENSEI® laparoscopic tethered gamma probe system will be evaluated (validated with a questionnaire filled in by the surgeons).

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: We expect no additional burden or physical discomfort to be associated with participation. The risk associated with participation in this feasibility study is considered to be nihil since the SLN detection rates with the SENSEI® laparoscopic tethered gamma probe will be validated with the conventional rigid gamma probe. Therefore, there is no risk of lower SLN detection rates in these patients. We don’t expect the use of the SENSEI®
laparoscopic tethered gamma probe to constitute any additional intraoperative or postoperative risks compared to conventional rigid laparoscopic gamma probe guided procedures. In the current procedure patients are already exposed to radiation of 99mTc-nanocolloid, so this will not result in additional risks. The SENSEI® laparoscopic tethered gamma probe is non-radiation emitting. The SENSEI® laparoscopic tethered gamma probe has undergone comprehensive preclinical testing, which demonstrates proof of concept and safety for its intended use. A full Risk Management Review has been conducted in accordance with ISO 14971:2012.
It is hypothesized that the small size of the SENSEI® laparoscopic tethered gamma probe and the ability to manipulate the probe with the laparoscopic forceps will enable more accurate and complete detection of SLNs in comparison to the rigid laparoscopic gamma probes currently available. This study offers the potential benefits of more complete SLN (and cancer) detection to participants.

We hypothesize that the SENSEI® laparoscopic tethered gamma probe will enable a more accurate and faster detection of sentinel lymph nodes in comparison to the rigid laparoscopic gamma probes currently used in cervical cancer sentinel node biopsy.

Primary and secondary outcomes will be assessed during (or directly after) surgical procedure.