Rationale: In muscle-invasive bladder cancer (MIBC), lymph node invasion has proven to be an independent predictor of disease recurrence and cancer-specific survival. We evaluated the feasibility of targeting the sentinel node (SN) for biopsy in MIBC patients using the hybrid tracer indocyanine green (ICG)–^99mTc-nanocolloid for simultaneous radioguidance and fluorescence guidance. Methods: Twenty histologically confirmed cN0M0 MIBC patients (mean age, 63.3 years; range, 30–82 years), scheduled for radical cystectomy with SN biopsy and extended pelvic lymph node dissection (ePLND), were prospectively included. Twelve patients were operated on following neoadjuvant chemotherapy. The patients received lymphoscintigraphy as well as SPECT/CT after 4 transurethral injections of ICG-^99mTc-nanocolloid (mean, 208 MBq; range, 172–229 MBq) around the tumor/scar in the detrusor muscle of the bladder on the day before radical cystectomy. Sentinel node resection was performed under radioguidance and fluorescence guidance. Results: Nineteen patients could be analyzed. On preoperative imaging, SNs could be identified in 10 patients (53%; mean, 1.6 SN/patient), which revealed drainage pathways outside the ePLND in 20% of the patients. Interesting to note is that 2 patients (10%) with preoperative nonvisualization displayed fluorescent and radioactive SNs during surgery. Location of the primary tumor near the left lateral side of the bladder seemed to be a factor for nonvisualization. Nodal harvesting with ePLND varied among patients (mean, 23.3). Histopathology confirmed tumor-positive nodes in 4 (21%) of all patients. In the 2 patients where an SN could be identified, the ePLND specimens were tumor-negative. All patients with tumor-positive nodes had advanced disease (stage III). Conclusion: Sentinel node biopsy in bladder cancer using the hybrid tracer ICG-^99mTc-nanocolloid is feasible, and preoperative imaging is predictive for the ability to perform SN biopsy in 83% of the patients who displayed an SN. In patients with a successful preoperative SN mapping using lymphoscintigraphy and SPECT/CT, the intraoperative SN guidance and detection were effective, even outside the ePLND area. As such, this study underscores the critical role that preoperative imaging plays in challenging image-guided surgery applications.

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.

The prognostic value of lymphovascular invasion (LVI) after radical cystectomy (RC) remains debated, particularly in relation to pathological tumor stage (pT) and pathological nodal status (pN). We analyzed the strongest prognostic factors for disease-specific survival (DSS) in a multicenter study with local pathology review, including 1229 patients with cT1-4aN0M0 urothelial bladder cancer (BC) treated with upfront RC (1986-2020). A classification and regression tree (CART) analysis was used to prioritize prognostic variables. CART identified pN status as the primary discriminator, followed by LVI as the second strongest prognostic factor within pN-negative disease. LVI was present in 584 patients (48%). Median follow-up was 4.1 yr. In multivariable Cox regression models, LVI was independently associated with DSS in both the pN-negative (hazard ratio [HR] 1.50, 95% confidence interval (CI) = 1.16-1.94; p = 0.002) and pN-positive (HR 1.38, 95%CI = 1.04-1.83; p = 0.03) cohorts. CART defined three prognostic groups: favorable prognosis (pN negative/LVI negative), intermediate prognosis (pN negative/LVI positive), and poor prognosis (pN positive), with 5-yr DSS of 65%, 48%, and 25%, respectively. Among patients with poor prognosis, adjuvant chemotherapy (AC) was associated with longer DSS (HR 0.47; p < 0.001). In the intermediate-prognosis group, receipt of AC was not statistically associated with DSS (HR 0.66, 95%CI 0.39-1.10; p = 0.10). Combined assessment of pN status and LVI provides clinically meaningful postoperative risk stratification that may help refine postoperative risk assessment, surveillance planning, and multidisciplinary discussion regarding adjuvant treatment.