Ultrasound-guided intratumoral indigo carmine injection for intraoperative, surgeon-performed tumor localization.

BACKGROUND The purpose of this study was to evaluate the feasibility of ultrasound-guided intratumoral indigo carmine injections for intraoperative localization of small head and neck tumors and to introduce our surgeon-performed technique. METHODS In total, 23 patients who had tumors ≤1.5 cm that were not palpable by 2 head and neck surgeons were enrolled in this prospective study. RESULTS Ultrasound-guided intratumoral indigo carmine injections successfully targeted tumors in 22 patients (95.7%). The mean preinjection target tumor size was 0.8 cm. After an average injection of 0.7 mL indigo carmine, the mean target tumor size increased to 1.0 cm, which enhanced visual demarcation because of the increased tumor size. In these patients, we successfully and uneventfully resected the target tumors with ultrasound-guided intratumoral indigo carmine injection assistance. CONCLUSION Ultrasound-guided intratumoral indigo carmine injections were technically feasible as an intraoperative procedure and were performed safely by a head and neck surgeon to facilitate localization of small head and neck tumors, even in revision cases.