Z Li, N Jin, L Zhu, H Zhang
The objective was to evaluate the technical feasibility, geometric accuracy, and preliminary short-term safety of using a multimodal, image-guided, robot-assisted iodine-125 seed implantation targeting the stylomastoid foramen and high-risk perilesional regions in selected patients with parotid adenoid cystic carcinoma with facial nerve involvement. A total of 23 consecutive patients treated between January 2020 and January 2023 were reviewed. Preoperative puncture planning was conducted using fused computed tomography (CT)/magnetic resonance imaging datasets. Intraoperative percutaneous needle placement and radioactive seed implantation were performed under robotic navigation. Postoperative CT imaging was obtained within 24 h to quantify implantation accuracy by calculating the spatial deviation between planned and actual seed positions. All patients were followed for up to 3 years, during which neurological function and intracranial tumor progression were systematically evaluated using clinical assessment and imaging. All surgeries were completed successfully without intraoperative incidents or significant perioperative complications. The mean particle placement error was 1.46 ± 0.85 mm (95% confidence interval: 1.09-1.83 mm), with intraoperative blood loss of 2-3 mL. During subsequent follow-up, no further neurological deficits were observed, and serial imaging revealed stable disease in 16 patients, partial response in six, and local progression without intracranial extension in one. The employment of robot-assisted iodine-125 brachytherapy has the potential to offer a safe, accurate, and minimally invasive clinical option for focal neural-pathway irradiation in a selected group of high-risk parotid adenoid cystic carcinoma patients. However, the confirmation of long-term oncological and neurological benefits necessitates the performance of prospective controlled studies.