Abstracts

Rationale:
MRI-guided laser interstitial thermal therapy (MRgLITT) is a novel minimally invasive treatment for drug resistant epilepsy (DRE) in children. Although MRgLITT is a promising therapy, the effectiveness of MRgLITT remains uncertain. The aim of this multi-centre MRgLITT (PEP-LITT) registry is to evaluate outcomes of MRgLITT in children with DRE.
Method:
The PEP-LITT registry has recruited children treated with MRgLITT from eight (6 US and 2 Canadian) pediatric epilepsy surgery centers across North America. Five additional centers have agreed to participate in the registry and institutional research ethics applications are underway. Inclusion criteria are children under 18 years of age with focal DRE who will be undergoing or have undergone MRgLITT. Exclusion criteria include corpus callosotomy or hemispherotomy utilizing MRgLITT. Data on baseline clinical characteristics, MRgLITT procedure including ablation site, type of lesion, length of stay, complications, number of MRgLITT procedures, and seizure outcome were collected electronically using REDCap.
Results:
To date, 129 children who were treated with MRgLITT have been enrolled into the registry. Mean age at MRgLITT was 10.7 years (SD=5.2), mean age at seizure onset was 4.6 years (SD=4.6), and mean number of antiepileptic drugs was 1.9 (SD=1.4). Abnormal MRI findings were present in 111 (86%) patients, with hypothalamic hamartoma being the most common lesion (n=33), followed by focal cortical dysplasia (n=23). Complications relating to MRgLITT occurred in 28 patients (22%), including 16 (12%) cases of transient neurologic deficits and 2 cases (2%) of permanent neurologic deficits. There was no major intracranial hemorrhage. 30-day mortality post MRgLITT was reported in one patient. Mean length of hospital stay was 3.2 days (SD=3.7), with a median of one day hospital stay. Among 93 patients in whom 1-year seizure outcome was available, seizure freedom was reported in 52 patients (56%). Twelve (9%) patients had more than one MRgLITT procedure, and 7 of these achieved seizure freedom.
Conclusion:
Preliminary findings indicate that over half of the children treated with MRgLITT achieved seizure freedom at 1-year follow-up, and permanent neurological deficits were rare.  The PEP-LITT registry will provide data for future analysis comparing seizure and health-related quality of life outcomes of MRgLITT to resective epilepsy surgery. Understanding the benefits and risks of MRgLITT will assist with decision making process on treatment options.
Funding:
:This study has been funded by the Pediatric Epilepsy Research Foundation (PERF).