목적: We attempted to evaluate the feasibility of ultrasonography (US)-guided intratumoral indigo carmine injections (US-III) for the intraoperative localization of small target tumors and to introduce our surgeon-performed technique. 방법:A total of 23 patients were enrolled in this prospective study. All intraoperative US-III and followed surgeries were performed by one head and neck surgeon. For US-III, we used the following equipment: an US machine (HD3; Philips Healthcare, Ridgefield Park, NJ, USA) with a high-frequency transducer (7¬–12 MHz), 0.8% undiluted indigo carmine, and a 1-mL syringe fitted with a 25-gauge needle. All US-III procedures were performed in the operating room prior to surgical skin incisions under general anesthesia. After setting the patient position to one suitable for each surgical case, the surgeon performed an US of the neck. After preparing the skin with an alcohol wipe, 0.8% indigo carmine was injected into the target tumor using 1-mL syringe that was fitted with a 25-gauge needle in a parallel fashion under US guidance. Once the needle tip location was confirmed to be inside the tumor, indigo carmine was injected slowly (Figure 2). The injection amounts of indigo carmine were adjusted according to the tumor size; however, the injected volumes did not exceed 1 mL in any cases. All US-III procedures were completed within 15 minutes. 결과:The US-III successfully targeted tumors in 22 patients (95.7%). The mean pre-injection size of the target tumors 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 due to the increased tumor size. In these patients, we successfully and uneventfully resected the target tumors with US-III assistance. 결론:US-III was technically feasible as an intraoperative procedure and was performed safely by a head and neck surgeon to facilitate the localization of small tumors, even in revision cases.