Lesion Optimization for Laser Ablation: Fluid Evacuation Prior to Laser-Induced Thermal Therapy

Abstract

Background: Magnetic resonance-guided laser-induced thermal therapy (MRgLITT) is a minimally invasive surgical procedure for ablating intracranial lesions. The presence of a fluid body can sequester thermal energy generated by the laser catheter, which compromises the performance of MRgLITT, resulting in suboptimal ablation of cystic lesions. We report our use of stereotactic fluid evacuation followed by MRgLITT in 2 patients with cystic brain tumors. This is the first report on lesion optimization by fluid aspiration before MRgLITT.

Methods: Two cystic tumors in 2 patients were treated. In 1 patient, an external ventricular drain was placed stereotactically to allow drainage of cystic fluid 1 day before laser ablation. In the second patient, a stereotactic biopsy needle was used to aspirate the cystic fluid immediately before laser ablation. The remaining solid portions of the both tumors were ablated using the Visualase system. Both patients were followed clinically and radiologically after the procedures.

Results: Stereotactic placement of an external ventricular drain and a biopsy needle both successfully resulted in fluid evacuation. MRgLITT was performed without any complications in both patients after fluid evacuation. Both patients demonstrated clinical and radiologic improvement after the procedure.

Conclusions: Cystic fluid evacuation is a promising strategy for optimizing intracranial cystic lesions for MRgLITT. This novel approach may broaden the utility of MRgLITT in the management of various technically demanding lesions.

Keywords: Fluid evacuation; Intracranial cystic tumor; Laser ablation; Lesion optimization; Magnetic resonance–guided laser therapy.