Abstract: PURPOSE: To investigate the feasibility and efficacy of accurate implantation of ¹²⁵I seeds guided by digital navigation for the treatment of adenogenous malignant tumors of the skull base. METHODS: A series of 9 patients received digital navigation guided interstitial ¹²⁵I seeds implantation. CT scanning was performed precisely and the plan of ¹²⁵I implantation was designed systematically with the aid of Treatment Planning System(TPS) and AccuNavi-A navigation system. ¹²⁵I was delivered into the target region according to the position and direction defined by the designed implantation plan and digital navigation during the process of implantation. Real-time assessment was required to find if the position of ¹²⁵I corresponded with preoperative plan. All patients underwent regular reexamination to compare the tumor size preoperatively and postoperatively. The recurrent rate and local control rate were evaluated and the adverse events observed. RESULTS: ¹²⁵I seeds were implanted successfully in target-area of all 9 patients. The recurrence rate was 11.1% and the local control rate (CR+PR) was 77.8% without severe side effects during follow-up at 3-36 months in all patients. CONCLUSIONS: Traditional resection carried a high risk of postoperative complications because the base of the skull is concealed, with a narrow space and limited field of vision. Accurate implantation of ¹²⁵I with the use of digital navigation imaging guidance is an effective,minimally invasive and safe method for treating adenogenous malignant tumors of the skull base and should be considered for conditional use.

Key words: Digital navigation, ¹²⁵I seeds, Adenogenous malignant tumors of skull base, Interstitial brachytherapy