Abstract
Objective:
Stereoelectroencephalography (SEEG)-guided radiofrequency ablation (RFA) is increasingly being used as a treatment for drug-resistant localization-related epilepsy. The aim of this study is to analyze the successes and failures using RFA and how response correlates with surgical epilepsy treatment outcomes.
Methods:
We retrospectively reviewed 62 patients who underwent RFA via SEEG electrodes. After excluding 5, the remaining 57 were classified into subgroups based on procedures and outcomes. Forty patients (70%) underwent a secondary surgical procedure, of whom 32 were delayed: 26 laser interstitial thermal therapy (LITT), 5 resection, 1 neuromodulation. We determined the predictive value of RFA outcome upon subsequent surgical outcome by categorizing the delayed secondary surgery outcome as success (Engel I/II) vs. failure (Engel III/IV). Demographic information, epilepsy characteristics, and the transient time of seizure freedom after RFA was calculated for each patient.
Results:
Twelve of 49 patients (24.5%) who had RFA alone and delayed follow-up achieved Engel class I. Of the 32 patients who underwent a delayed secondary surgical procedure, 15 achieved Engel class I, 9 Engel class II (24 successes) and 8 were considered failures (Engel class III/IV). The transient time of seizure freedom after RFA was significantly longer in the success group (4 mo, SD 2.6) as compared to the failure group (0.75 mo, SD 1.16; p<0.001). Additionally, there was a higher portion of pre-operative lesional findings in patients in the RFA alone and delayed surgical success group (p=0.03) and a longer time to seizure recurrence in the presence of lesions (p<0.05). Side effects occurred in 1% of patients.
Significance:
In this series, RFA provided a treatment during SEEG-guided intracranial monitoring that led to seizure freedom in ~25% of patients. Of the 70% that underwent delayed surgery, longer transient time of seizure freedom after RFA was predictive of the results of the secondary surgeries, 74% were LITT.
JUN