Study Objective First, to introduce the use of Sensitive Firefly in robotic surgery. Second, to compare the efficacy of Firefly (currently in use) to Sensitive Firefly Fluorescence Imaging for ureter identification using the IS-001 (IND 124804) investigational contrast agent. Design Prospective, open-label, 2-stage dose escalation clinical trial design. Setting Multi-center; academic and academic affiliated community hospitals. Patients or Participants Women (n=30) between ages 18 and 75 scheduled to undergo robotic gynecological procedures using a da Vinci® Surgical System with Sensitive Firefly® Fluorescent Imaging. Interventions A single IV slow bolus injection of fluorescent dye IS-001 at 2 mg/mL was administered, with intra-operative identification of the ureter compared between white light endoscopy, Firefly®, and Sensitive Firefly Fluorescence Imaging modalities. Measurements and Main Results Visualization of the ureter was evaluated both quantitatively and based on a qualitative surgeon rating score using Firefly, Sensitive Firefly with IS-001 versus white light endoscopy. Ureter visibility was measured at the level of the pelvic brim (PB) with a tissue depth of ∼ 0.5 mm, and at the level of the uterine artery (UA) with an estimated tissue depth of ∼ 2-3 mm; both of which are common sites of ureteral injury during hysterectomy. Measurements were at time intervals of 10, 30, and 60 minutes after IS-001 injection using each modality. Early trial results indicate that Sensitive Firefly's boosted near-infrared sensitivity facilitated clear IS-001 fluorescent ureter detection at both shallow (PB) and deep (UA) locations. Sensitive Firefly offered a 5-fold improvement in ureter visibility at the deeper uterine artery location compared to white light endoscopy and a marked benefit compared to the existing Firefly Fluorescent Imaging system. Conclusion The use of Sensitive Firefly showed improved transperitoneal IS-001 fluorescent visualization and delineation of the ureter at greater tissue depths and for longer periods of time when compared to the current Firefly Fluorescent Imaging System. First, to introduce the use of Sensitive Firefly in robotic surgery. Second, to compare the efficacy of Firefly (currently in use) to Sensitive Firefly Fluorescence Imaging for ureter identification using the IS-001 (IND 124804) investigational contrast agent. Prospective, open-label, 2-stage dose escalation clinical trial design. Multi-center; academic and academic affiliated community hospitals. Women (n=30) between ages 18 and 75 scheduled to undergo robotic gynecological procedures using a da Vinci® Surgical System with Sensitive Firefly® Fluorescent Imaging. A single IV slow bolus injection of fluorescent dye IS-001 at 2 mg/mL was administered, with intra-operative identification of the ureter compared between white light endoscopy, Firefly®, and Sensitive Firefly Fluorescence Imaging modalities. Visualization of the ureter was evaluated both quantitatively and based on a qualitative surgeon rating score using Firefly, Sensitive Firefly with IS-001 versus white light endoscopy. Ureter visibility was measured at the level of the pelvic brim (PB) with a tissue depth of ∼ 0.5 mm, and at the level of the uterine artery (UA) with an estimated tissue depth of ∼ 2-3 mm; both of which are common sites of ureteral injury during hysterectomy. Measurements were at time intervals of 10, 30, and 60 minutes after IS-001 injection using each modality. Early trial results indicate that Sensitive Firefly's boosted near-infrared sensitivity facilitated clear IS-001 fluorescent ureter detection at both shallow (PB) and deep (UA) locations. Sensitive Firefly offered a 5-fold improvement in ureter visibility at the deeper uterine artery location compared to white light endoscopy and a marked benefit compared to the existing Firefly Fluorescent Imaging system. The use of Sensitive Firefly showed improved transperitoneal IS-001 fluorescent visualization and delineation of the ureter at greater tissue depths and for longer periods of time when compared to the current Firefly Fluorescent Imaging System.