SEEG-informed independent therapeutic trajectory planning for robot-assisted stereotactic radiofrequency thermocoagulation in drug-resistant epilepsy: an exploratory technical series of six cases

Radiofrequency thermocoagulation (RFTC) guided by stereo-electroencephalography (SEEG) is a minimally invasive treatment for drug-resistant epilepsy, but the coagulation distribution is constrained by diagnostic electrode placement. In this exploratory case series, we evaluated the technical feasibility, intraoperative workflow, and preliminary safety of robot-assisted stereotactic RFTC with trajectories planned independently of diagnostic electrodes, targeting the SEEG-defined seizure-onset zone and, when coverage permitted, early propagation regions. We retrospectively analyzed six patients who underwent robot-assisted stereotactic RFTC with SEEG-based independent therapeutic trajectory (ITT) planning between February 2024 and February 2026. The epileptogenic zone was delineated by integrating SEEG, anatomical imaging, and clinical information. A monopolar probe was robotically guided along each trajectory, and stepwise pull-back coagulation was combined across trajectories to create a three-dimensional ablation. Surgical parameters, ablation distribution, and adverse events were assessed descriptively. Probe insertion and multi-trajectory ablation were completed as planned in all six procedures, with a mean of 5.3 ± 2.7 trajectories and 21.8 ± 14.7 coagulation points. Mean operative and operating room times were 145.7 ± 54.7 and 276.0 ± 45.8 min, respectively. No hemorrhage or infection occurred; however, one patient developed permanent homonymous hemianopia consistent with optic radiation injury, a major complication. At the last follow-up, four of six patients achieved Engel class I–II outcomes; given the small, heterogeneous sample, these findings do not establish treatment efficacy. Robot-assisted stereotactic RFTC enabled three-dimensional ablation unconstrained by diagnostic electrode placement. However, the permanent visual-field deficit highlights the need for particular caution near major white matter tracts because of the risk of off-target injury. Although clinical efficacy remains unproven, this study demonstrates the feasibility of a systematic, transferable planning framework that, building on lesion-guided RFTC, translates SEEG findings into independent therapeutic trajectories, and underscores the importance of preoperative planning that prioritizes white matter preservation.