Hybrid Surgical Guidance in Urologic Robotic Oncological Surgery

Abstract

Urologic oncological surgery increasingly makes use of robotic systems to realize precise and minimally invasive resections, convent to shorter hospital stays and faster recovery times. The dexterity gains enabled through procedures such as robot-assisted (RA) prostatectomy have helped realize significant advancements in recent years. Complementing these effects via the used of hybrid tracers that illuminate surgical targets, i.e., cancerous tissue, has helped advance the surgical decision making via enhanced visualization. A well-known example is Indocyanine green (ICG)-Technetium-99m (^99mTc)-nanocolloid, a hybrid extension of the radiopharmaceutical ^99mTc-nanocolloid. These hybrid tracers provide a direct link between preoperative imaging roadmaps and intraoperative target identification, and improve efficiency, accuracy, and confidence of the urologist in procedures such as sentinel lymph node biopsy (SLNB). Receptor-targeted hybrid tracer analogues, for e.g., prostate specific membrane antigen (PSMA), are also being explored as an extension of the ongoing efforts that use radiotracers such as ^99mTc-PSMA-I&S. Together, these efforts jointly pave the way for novel techniques in intraoperative lesion localization in other urological malignancies. This narrative review discusses the potential use of hybrid tracers in robotic oncological urology, including different imaging techniques and their applications for tumor localization for prostate, bladder, and kidney cancer.

Keywords: bladder cancer; hybrid tracers; image guided surgery; kidney cancer; prostate cancer; robot assisted surgery; urology.

Figure 1

Image-guidance in robotic surgery. (A) Robot surgery, (B) available tracer designs with varying targeting moieties and imaging labels that allow image guidance, and (C) tools for intraoperative guidance. Fluorescence image obtained from KleinJan et al., Eur Urol 2014 [14], Navigation images obtained from KleinJan et al., JNM 2016 [15], and radioguidance (gamma Drop in probe) image obtained from van Gennep et al., EJNMMI 2025 [16].

Figure 2

Devices for intraoperative guidance. (A) Drop-in gamma probe (Ref. [24]), (B) robotic SPECT (Ref. [49]), (C) fluorescence imaging (Ref. [14]), and (D) Click-on fluorescence probe (Ref. [50]).

Figure 3

Tracer clearance and tumour visualization. (A) Clinical example: the use of the hy-brid PSMA-targeting tracer 68Ga-P3 in robotic surgery (Red arrow: tumor location on PSMA-PET/CT; * : reference point for white light and fluorescence imaging; white dashed stripe: tumor location prostate, (adapted from ref. [66])). (B) schematic rep-resentation of the renal clearance pathway. (C) Dislocation prostate from tracer-containing bladder during prostatectomy (left image) and contamination with fluorescent dye-containing urine in the surgical field after prostatectomy in a prostate cancer patient (right image; images obtained from ref. [37]). (D) Prostate cancer (left image) and fluorescence-based discrimination between lesions and surrounding tissue (right image; fluorescence image obtained from ref. [67], dashed = location tu-mor). Anatomical images created using Biodigital.com.

Figure 4

Hybrid image guidance in renal and kidney cancer. (A) Fluorescence-guided tumor visualization using the hybrid carbonic anhydrase IX (CAIX) targeting antibody-based tracer ¹¹¹In-girentuximab-IRDye800CW in an ex vivo kidney perfusion model [41]. (B) Hybrid sentinel node imaging based on combined pre- and intraoperative guidance using the hybrid tracer ICG-^99mTc-nanocolloid [16,75].