Optical guidance in stereotactic neurosurgery
With LDF our research has defined typical optical trajectories towards brain targets commonly used in deep brain stimulation (DBS) implantations. LDF records the microvascular blood flow along a trajectory and can thus indicate increased blood flow with the forward looking probe. Both LDF and DRS can detect shades of grey-white tissue intraoperatively and thus help define tissue type during surgery. The methods have been used in more than 130 DBS implantations including over 3000 recordings. LDF also make unique studies of the brain’s microcirculation possible. Recently LDF probes were also combined with fluorescence, and microelectrode recording (MER).
Data from DRS can either be processed as similar optical trajectories as for LDF, if the same wavelength of 780 nm is processed. DRS can also be used for estimation of the brain tissues SO2 saturation. This method has been evaluated during DBS implantations and neurointensive care monitoring.
Fluorescence guided brain tumor surgery
5-ALA fluorescence measurements of high grade brain tumor tissue can be detected either with the blue-light neurosurgical microscope or with the in-house developed fluorescence probe system. Under the microscope, the hand-held probe enhances the fluorescence in the tumor marginal zone. The hand-held probe can also be used as stand-alone fluorescence measurements in open surgery. Modification of the probe’s outer dimensions to a stereotactic frame it can be applied also for identification of tumor tissue during stereotactic biopsies.