Sentinel lymph node biopsy using indocyanine green (ICG) and near-infrared (NIR) fluorescence imaging has been explored as a minimally invasive tool for nodal staging in prostate cancer. However, challenges exist due to the absence of a single, anatomically consistent sentinel node, as the prostate drains into multiple lymphatic channels. We present a case utilizing CT-guided ICG injection for targeted lymph node dissection during robotic-assisted laparoscopic radical prostatectomy (RaLP).

A 71-year-old man presented with elevated PSA levels (16.9 ng/mL). Multiparametric MRI revealed a PI-RADS 5 lesion in the right peripheral zone with extraprostatic extension and right seminal vesicle invasion. A borderline-sized lymph node at the right internal iliac artery region was suspicious for metastasis. MR/US fusion biopsy confirmed prostate adenocarcinoma, Gleason 4+4. The patient underwent RaLP with pre-operative CT-guided localization of the suspicious node using 0.5% diluted ICG. Targeted dissection of the node was completed intraoperatively without complications. Final pathology revealed Gleason score 4+5, Grade Group 5, pT3b disease with bilateral seminal vesicle invasion and established extraprostatic extension. All margins were negative. One of two CT-localized lymph nodes showed metastatic adenocarcinoma, and the remaining 18 lymph nodes were negative.

This case highlights a hybrid approach integrating imaging, interventional radiology, and fluorescence-guided surgery. While a 2025 meta-analysis by Chou et al. reported high per-patient sensitivity (87%) and negative predictive value (95%) of ICG-guided SLND, per-node sensitivity remained modest (53%) [1]. Similarly, Ma et al. observed pooled sensitivity and specificity of 71% and 68%, respectively, reinforcing the limitations of node-level accuracy [2]. Our method addresses these concerns by pre-operatively pinpointing suspicious lymph nodes for precise intraoperative targeting. Notably, ICG fluorescence imaging has demonstrated broad utility beyond urological surgery. In thoracic surgery, it has been employed for localization of pulmonary nodules, segmental plane identification, and sentinel lymph node mapping, with promising accuracy and safety [3,4]. Surgical technique in this case followed principles described by Janetschek et al., emphasizing cranial-to-caudal dissection and en bloc removal to minimize dye leakage and background fluorescence [5].

Pre-operative CT-guided localization using ICG dye is a safe and effective adjunct to fluorescence-guided lymph node dissection in RaLP. By enabling precise targeting of MRI-suspected lymph nodes, this technique may improve the detection of clinically significant nodal metastases while preserving the benefits of minimally invasive surgery.