====== Stereotactic laser ablation ======

see [[Laser interstitial thermal therapy]].
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Stereotactic [[laser]] [[ablation]] and [[neurostimulator]] placement represent an evolution in staged surgical [[intervention]] for [[epilepsy]]. As this practice evolves, optimal targeting will require standardized [[outcome]] measures that compare [[electrode]] [[lead]] or laser source with postprocedural changes in [[seizure]] frequency. 

Miller et al., proposed and presented a novel [[stereotactic]] [[coordinate system]] based on mesial temporal anatomical [[landmark]]s to facilitate the [[planning]] and delineation of outcomes based on extent of ablation or region of stimulation within mesial temporal structures.

The body of the [[hippocampus]] contains a natural axis, approximated by the interface of [[cornu ammonis]] ([[CA4]]) and the [[dentate gyrus]]. The [[uncal recess]] of the [[lateral ventricle]] acts as a landmark to characterize the anterior-posterior extent of this axis. Several volumetric rotations are quantified for alignment with the mesial temporal coordinate system. First, the brain volume is rotated to align with standard [[anterior commissure]]-[[posterior commissure]] (AC-PC) space. Then, it is rotated through the axial and sagittal angles that the hippocampal axis makes with the AC-PC line.

Using this coordinate system, customized [[MATLAB]] software was developed to allow for intuitive standardization of targeting and interpretation. The angle between the AC-PC line and the hippocampal axis was found to be approximately 20°-30° when viewed sagittally and approximately 5°-10° when viewed axially. Implanted electrodes can then be identified from CT in this space, and [[laser]] tip position and burn geometry can be calculated based on the intraoperative and postoperative MRI.

With the advent of stereotactic surgery for mesial temporal targets, a mesial temporal stereotactic system is introduced that may facilitate operative planning, improve surgical outcomes, and standardize outcome assessment
((Miller KJ, Halpern CH, Sedrak MF, Duncan JA, Grant GA. A novel mesial temporal
stereotactic coordinate system. J Neurosurg. 2018 Jan 1:1-9. doi:
10.3171/2017.7.JNS162267. [Epub ahead of print] PubMed PMID: 29372873.
)).