Identification of Pediatric Tumors Intraoperatively Using Indocyanine Green (ICG)

ICG-labeled PD-L1-antagonistic affibody dimer for tumor imaging and enhancement of tumor photothermal-immunotherapy

In clinical practice, tumor-targeting diagnosis and immunotherapy against programmed death ligand 1 (PD-L1) have a significant impact. In this research, a PD-L1-antagonistic affibody dimer (ZPD-L1) was successfully prepared through Escherichia coli expression system, and conjugated with the photosensitizer of ICG via N-hydroxysuccinimide (NHS) ester to develop a novel tumor-targeting agent (ICG-ZPD-L1) for both tumor imaging diagnosis and photothermal-immunotherapy simultaneously. In vitro, ZPD-L1 could specifically bind to PD-L1-positive LLC and MC38 tumor cells, and ICG-ZPD-L1-mediated photothermal therapy (PTT) also showed excellent phototoxicity to these tumor cells. In vivo, ICG-ZPD-L1 selectively enriched into the PD-L1-positive MC38 tumor tissues, and the high-contrast optical imaging of tumors was obtained. ICG-ZPD-L1-mediated PTT exhibited a potent anti-tumor effect in vivo due to its remarkable photothermal properties. Furthermore, ICG-ZPD-L1-mediated PTT significantly induced the immunogenic cell death (ICD) of primary tumors, promoted maturation of dendritic cells (DCs), up-regulated anti-tumor immune response, enhanced immunotherapy, and superiorly inhibited the growth of metastatic tumors. In addition, ICG-ZPD-L1 showed favorable biosafety throughout the brief duration of treatment. In summary, these results suggest that ICG-ZPD-L1 is a multifunctional tumor-targeting drug integrating tumor imaging diagnosis and photothermal-immunotherapy, and has great guiding significance for the diagnosis and treatment of clinical PD-L1-positive tumor patients.

Indocyanine green (ICG) fluorescence technology in pediatric robotic surgery

This study aimed to report our experience in indocyanine green (ICG) fluorescence-guided surgery (FGS) in pediatric robotics. The data of 55 patients (35 boys and 20 girls), who underwent robotic surgery using ICG fluorescence in three institutions over the last 7 years, were retrospectively reviewed. The following robotic procedures were included: pyeloplasty (n = 21), complex Lich-Gregoir ureteral reimplantation (n = 8), varicocelectomy (n = 7), adnexal pathology resection (n = 8), partial nephrectomy (n = 4), nephrectomy (n = 4), renal cyst removal (n = 2), and excision of prostatic utricle (n = 1). The ICG was injected intravenously in all indications except for varicocele where intratesticular injection was done, and prostatic utricle or paraureteral diverticulum where trans-catheter injection was done. The ICG dosage was 0.2-0.3 mg/mL/kg. All the procedures were performed using da Vinci Xi platform. Firefly® allowed to switch form bright light to ICG-NIRF view and vice versa. All the procedures were accomplished in robotics without conversions to laparoscopy or open surgery. No episodes of allergy or anaphylaxis to ICG were recorded. An excellent ICG-NIRF view of target organs was obtained in all procedures. Based on our experience, we believe that application of ICG FGS in pediatric robotics enhances the identification of critical anatomical elements and pathological structures, thereby positively impacting both oncological and functional outcomes. This technique is safe, feasible, and versatile. We advocate the consideration of ICG as the standard of care in certain procedures such as partial nephrectomy, varicocele repair, tumor resection, and ovarian torsion. Nonetheless, further investigations are warranted to explore its potential broader applications in pediatric urology.

Indocyanine green (ICG) fluorescence-enhanced applications in pediatric surgery

The breadth of pediatric surgical practice and variety of anatomic anomalies that characterize surgical disease in children and neonates require a unique level of operative mastery and versatility. Intraoperative navigation of small, complex, and often abnormal anatomy presents a particular challenge for pediatric surgeons. Clinical experience with fluorescent tissue dye, specifically indocyanine green (ICG), is quickly gaining widespread incorporation into adult surgical practice as a safe, non-toxic means of accurately visualizing tissue perfusion, lymphatic flow, and biliary anatomy to enhance operative speed, safety, and patient outcomes. Experience in pediatric surgery, however, remains limited. ICG-fluorescence guided surgery is poised to address the challenges of pediatric and neonatal operations for a growing breadth of surgical pathology. Fluorescent angiography has permitted intraoperative visualization of colorectal flap perfusion for complex pelvic reconstruction and anastomotic perfusion after esophageal atresia repair, while its hepatic absorption and biliary excretion has made it an excellent agent for delineating the dissection plane in the Kasai portoenterostomy and identifying both primary and metastatic hepatoblastoma lesions. Subcutaneous and intra-lymphatic ICG injection can identify iatrogenic chylous leaks and improved yields in sentinel lymph node biopsies. ICG-guided surgery holds promise for more widespread use in pediatric surgical conditions, and continued evaluation of efficacy will be necessary to better inform clinical practice and identify where to focus and develop this technical resource.