Steerable DROP-IN radioguidance during minimal-invasive non-robotic cervical and endometrial sentinel lymph node surgery.

PURPOSE: The recently introduced tethered DROP-IN gamma probe has revolutionized the way robotic radioguided surgery is performed, fully exploiting the nature of steerable robotic instruments. Given this success, the current first-in-human study investigates if the DROP-IN can also provide benefit in combination with steerable non-robotic instruments during conventional laparoscopic surgery, showing equivalence or even benefit over a traditional rigid gamma probe.

METHODS: The evaluation was performed in ten patients during laparoscopic cervical (n = 4) and endometrial (n = 6) cancer sentinel lymph node (SLN) procedures. Surgical guidance was provided using the hybrid, or bi-modal, SLN tracer ICG-99m Tc-nanocolloid. SLN detection was compared between the traditional rigid laparoscopic gamma probe, the combination of a DROP-IN gamma probe and a steerable laparoscopic instrument (LaproFlex), and fluorescence imaging.

RESULTS: The gynecologists experienced an enlarged freedom of movement when using the DROP-IN + LaproFlex combination compared to the rigid laparoscopic probe, making it possible to better isolate the SLN signal from background signals. This did not translate into a change in the SLN find rate yet. In both cervical and endometrial cancer combined, the rigid probe and DROP-IN + LaproFlex combination provided an equivalent detection rate of 96%, while fluorescence provided 85%.

CONCLUSION: We have successfully demonstrated the in-human use of steerable DROP-IN radioguidance during laparoscopic cervical and endometrial cancer SLN procedures, expanding the utility beyond robotic procedures. Indicating an improved surgical experience, these findings encourage further investigation and consideration on a path towards routine clinical practice and improved patient outcome.

TRIAL REGISTRATION: HCB/2021/0777 and NCT04492995; https://clinicaltrials.gov/study/NCT04492995.