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Haj-Hosseini, N., Richter, J., Milos, P., Hallbeck, M. & Wårdell, K. (2018). 5-ALA fluorescence and laser Doppler flowmetry for guidance in a stereotactic brain tumor biopsy. Biomedical Optics Express, 9(5), 2284-2296
Open this publication in new window or tab >>5-ALA fluorescence and laser Doppler flowmetry for guidance in a stereotactic brain tumor biopsy
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2018 (English)In: Biomedical Optics Express, E-ISSN 2156-7085, Vol. 9, no 5, p. 2284-2296Article in journal (Refereed) Published
Abstract [en]

A fiber optic probe was developed for guidance during stereotactic brain biopsy procedures to target tumor tissue and reduce the risk of hemorrhage. The probe was connected to a setup for the measurement of 5-aminolevulinic acid (5-ALA) induced fluorescence and microvascular blood flow. Along three stereotactic trajectories, fluorescence (n = 109) and laser Doppler flowmetry (LDF) (n = 144) measurements were done in millimeter increments. The recorded signals were compared to histopathology and radiology images. The median ratio of protoporphyrin IX (PpIX) fluorescence and autofluorescence (AF) in the tumor was considerably higher than the marginal zone (17.3 vs 0.9). The blood flow showed two high spots (3%) in total. The proposed setup allows simultaneous and real-time detection of tumor tissue and microvascular blood flow for tracking the vessels.

Place, publisher, year, edition, pages
Optical Society of America, 2018
National Category
Medical Engineering
Identifiers
urn:nbn:se:liu:diva-147514 (URN)10.1364/BOE.9.002284 (DOI)000431181700022 ()29760987 (PubMedID)
Funder
Swedish Childhood Cancer Foundation, 2013-0043Linköpings universitet, LiU CancerRegion Östergötland, ALF LIO-599651
Note

Funding agencies: Linkoping University Cancer Organization; Swedish Childhood Cancer Organization [MT 2013-0043]; ALF Grants Region Ostergotland [LIO-599651]

Available from: 2018-04-23 Created: 2018-04-23 Last updated: 2018-05-23Bibliographically approved
Wårdell, K., Zsigmond, P., Richter, J. & Hemm, S. (2018). Optical Guidance System for Deep Brain Stimulation Surgery: from Experimental Studies to Clinical Use. In: : . Paper presented at Biophotonics Congress: Biomedical Optics Congress, The Diplomat Beach Resort, Hollywood, Florida USA, 3–6 April 2018. Hollywood, Florida, United States, Article ID CTh2B.3.
Open this publication in new window or tab >>Optical Guidance System for Deep Brain Stimulation Surgery: from Experimental Studies to Clinical Use
2018 (English)In: , Hollywood, Florida, United States, 2018, article id CTh2B.3Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Laser Doppler flowmetry (LDF) has been adapted for optical guidance during stereotactic deep brain stimulation (DBS) surgery. It has been used in more than 130 DBS implantations. The necessary steps to go from experimental studies to clinical use in the neurosurgical setting are reviewed.

Place, publisher, year, edition, pages
Hollywood, Florida, United States: , 2018
Series
(Microscopy/Translational/Brain/OTS)
National Category
Other Medical Engineering
Identifiers
urn:nbn:se:liu:diva-147678 (URN)10.1364/TRANSLATIONAL.2018.CTh2B.3 (DOI)978-1-943580-41-5 (ISBN)
Conference
Biophotonics Congress: Biomedical Optics Congress, The Diplomat Beach Resort, Hollywood, Florida USA, 3–6 April 2018
Funder
Swedish Research Council, 621-2013-6078Swedish Foundation for Strategic Research , BD15-0032
Available from: 2018-05-04 Created: 2018-05-04 Last updated: 2018-05-15Bibliographically approved
Rejmstad, P., Johansson, J. D., Haj-Hosseini, N. & Wårdell, K. (2017). A method for monitoring of oxygen saturation changes in brain tissue using diffuse reflectance spectroscopy. Journal of Biophotonics, 10(3), 446-455
Open this publication in new window or tab >>A method for monitoring of oxygen saturation changes in brain tissue using diffuse reflectance spectroscopy
2017 (English)In: Journal of Biophotonics, ISSN 1864-063X, E-ISSN 1864-0648, Vol. 10, no 3, p. 446-455Article in journal (Refereed) Published
Abstract [en]

Continuous measurement of local brain oxygen saturation (SO2) can be used to monitor the status of brain trauma patients in the neurocritical care unit. Currently, micro-oxygen-electrodes are considered as the “gold standard” in measuring cerebral oxygen pressure (pO2), which is closely related to SO2 through the oxygen dissociation curve (ODC) of hemoglobin, but with the drawback of slow in response time. The present study suggests estimation of SO2 in brain tissue using diffuse reflectance spectroscopy (DRS) for finding an analytical relation between measured spectra and the SO2 for different blood concentrations. The P3 diffusion approximation is used to generate a set of spectra simulating brain tissue for various levels of blood concentrations in order to estimate SO2. The algorithm is evaluated on optical phantoms mimicking white brain matter (blood volume of 0.5–2%) where pO2 and temperature is controlled and on clinical data collected during brain surgery. The suggested method is capable of estimating the blood fraction and oxygen saturation changes from the spectroscopic signal and the hemoglobin absorption profile.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2017
Keywords
oxygenation, diffuse reflectance spectroscopy, hemoglobin, optical phantom, human brain
National Category
Other Medical Engineering
Identifiers
urn:nbn:se:liu:diva-127362 (URN)10.1002/jbio.201500334 (DOI)000398216200012 ()27094015 (PubMedID)
Note

Funding agencies: Swedish Childhood Cancer Foundation; Swedish Research Council [621-2010-4216, 621-2013-6078]

Available from: 2016-04-22 Created: 2016-04-22 Last updated: 2017-04-20Bibliographically approved
Richter, J., Haj Hosseini, N., Hallbeck, M. & Wårdell, K. (2017). Combination of Hand-Held Probe and Microscopy for Fluorescence Guided Surgery in the Brain Tumor Marginal Zone. Photodiagnosis and Photodynamic Therapy, 18, 185-192
Open this publication in new window or tab >>Combination of Hand-Held Probe and Microscopy for Fluorescence Guided Surgery in the Brain Tumor Marginal Zone
2017 (English)In: Photodiagnosis and Photodynamic Therapy, ISSN 1572-1000, Vol. 18, p. 185-192Article in journal (Refereed) Published
Abstract [en]

Background

Visualization of the tumor is crucial for differentiating malignant tissue from healthy brain during surgery, especially in the tumor marginal zone. The aim of the study was to introduce a fluorescence spectroscopy-based hand-held probe (HHF-probe) for tumor identification in combination with the fluorescence guided resection surgical microscope (FGR-microscope), and evaluate them in terms of diagnostic performance and practical aspects of fluorescence detection.

Material and Methods

Eighteen operations were performed on 16 patients with suspected high-grade glioma. The HHF-probe and the FGR-microscope were used for detection of protoporphyrin (PpIX) fluorescence induced by 5-aminolevulinic acid (5-ALA) and evaluated against histopathological analysis and visual grading done through the FGR-microscope by the surgeon. A ratio of PpIX fluorescence intensity to the autofluorescence intensity (fluorescence ratio) was used to quantify the spectra detected by the probe.

Results

Fluorescence ratio medians (range 0 – 40) measured by the probe were related to the intensity of the fluorescence in the FGR-microscope, categorized as “none” (0.3, n = 131), “weak” (1.6, n = 34) and “strong” (5.4, n = 28). Of 131 “none” points in the FGR-microscope, 88 (67%) exhibited fluorescence with the HHF-probe. For the tumor marginal zone, the area under the receiver operator characteristics (ROC) curve was 0.49 for the FGR-microscope and 0.65 for the HHF-probe.

Conclusions

The probe was integrated in the established routine of tumor resection using the FGR-microscope. The HHF-probe was superior to the FGR-microscope in sensitivity; it detected tumor remnants after debulking under the FGR-microscope. The combination of the HHF-probe and the FGR-microscope was beneficial especially in the tumor marginal zone.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2017
Keywords
High-grade glioma, Fluorescence guided resection (FGR), 5-Aminolaevulinic acid (5-ALA), Fluorescence spectroscopy, Protoporphyrin (PpIX)
National Category
Medical Engineering
Identifiers
urn:nbn:se:liu:diva-134849 (URN)10.1016/j.pdpdt.2017.01.188 (DOI)000404315000028 ()28223144 (PubMedID)
Note

Funding agencies: Swedish Governmental Agency for Innovation Systems (Vinnova); Swedish Foundation for Strategic Research (SSF); Swedish Research Council (VR) [311-2006-7661, 523-2013-2735]; NovaMedTech; Swedish Childhood Cancer Foundation [MT 2013-0043]; ALF Grants Region

Available from: 2017-03-08 Created: 2017-03-08 Last updated: 2018-05-07Bibliographically approved
Alonso, F., Vogel, D., Wårdell, K. & Hemm-Ode, S. (2017). Comparison between intraoperative and chronic and deep brain stimulation. In: : . Paper presented at World Society for Stereotactic and Functional Neurosurgery, 17th Quadrennial meeting, Berlin June 26-29, 2017.
Open this publication in new window or tab >>Comparison between intraoperative and chronic and deep brain stimulation
2017 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

INTRODUCTION

The success of the deep brain stimulation (DBS) therapy relies primarily in the localization of the implanted electrode, implying the need of utmost accuracy in the targeting process. Intraoperative microelectrode recording and stimulation tests are a common procedure before implanting the permanent DBS lead to determine the optimal position with a large therapeutic window where side effects are avoided and the best improvement of the symptoms is achieved. Differences in dimensions and operating modes exist between the exploration and the permanent DBS electrode which might lead to different stimulation fields, even when ideal placement is achieved. The aim of this investigation is to compare the electric field (EF) distribution around the intraoperative and the chronic electrode, assuming that both have exactly the same position.

METHODS

3D models of the intraoperative exploration electrode and the chronically implanted DBS lead 3389 (Medtronic Inc., USA) were developed using COMSOL 5.2 (COMSOL AB, Sweden). Patient-specific MR images were used to determine the conductive medium around the electrode. The exploration electrode and the first DBS contact were set to current and voltage respectively (0.2mA(V) - 3 mA(V) in 0.1 mA(V) steps). The intraoperative model included the grounded guide tube used to introduce the exploration electrode; for the chronic DBS model, the outer boundaries were grounded and the inactive contacts were set to floating potential considering a monopolar configuration. The localization of the exploration and the chronic electrode was set according to the planned trajectory. The EF was visualized and compared in terms of volume and extension using a fixed isocontour of 0.2 V/mm.

RESULTS

The EF distribution simulated for the exploration electrode showed the influence of the parallel trajectory and the grounded guide tube. For an amplitude of e.g. 2 mA/2 V, the EF extension of the intraoperative was 0.6 mm larger than the chronic electrode at the target level; the corresponding difference in volume was 76.1 mm3.

CONCLUSION

Differences in the EF shape between the exploration and the chronic DBS electrode have been observed using patient-specific models. The larger EF extension obtained for the exploration electrode responds to its higher impedance and the use of current controlled stimulation. The presence of EF around the guide tube and the influence of the parallel trajectory require further experimental and clinical evaluation.

National Category
Medical Engineering
Identifiers
urn:nbn:se:liu:diva-139880 (URN)
Conference
World Society for Stereotactic and Functional Neurosurgery, 17th Quadrennial meeting, Berlin June 26-29, 2017
Available from: 2017-08-21 Created: 2017-08-21 Last updated: 2017-08-21
Wårdell, K., Johansson, J. & Alonso, F. (2017). Deep brain stimulation: software for patient-specific electric field simulations. In: : . Paper presented at World Society for Stereotactic and Functional Neurosurgery, 17th Quadrennial meeting, Berlin June 26-29, 2017.
Open this publication in new window or tab >>Deep brain stimulation: software for patient-specific electric field simulations
2017 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Introduction

The electric field (EF) around the active deep brain stimulation (DBS) contact is of interest for optimizing the therapeutic effect. We have previously developed a method for simulation and visualization of the EF. The aim of the project is to improve the software for quick and user friendly simulations.  

Methods

The ELMA software for brain model creation has been improved by adding quick ROI selection and transformation to an electrical conductivity map based on tissue classification through multiple slices of the preoperative MRI. These data are used as input for Comsol Multiphysics simulations of the EF. Two points along the position of the lead, as seen in the postoperative images, are used for correct placement in the brain model. Multiple DBS lead models are pre-programmed. The active contact and amplitude are user-selected.

Results

After a simulation the result is visualized with a user defined isolevel or isosurface superimposed on the patients preoperative MRI. An example is shown in Fig. 1. The 3389 lead is places in zona inserta (Zi) and contact 1 activated with 2 and 4 V respectively. An isolevel of 0.2 V/mm is used corresponding to a ~ 3-4 µm axon diameter when using a pulse length of 60 µs. More examples will be presented at the meeting.

Conclusion

The software for patient-specific simulations of EF around DBS electrodes has been improved for quicker simulations and more DBS leads. As a next step user friendly Apps will be implemented.

National Category
Medical Engineering
Identifiers
urn:nbn:se:liu:diva-139879 (URN)
Conference
World Society for Stereotactic and Functional Neurosurgery, 17th Quadrennial meeting, Berlin June 26-29, 2017
Available from: 2017-08-21 Created: 2017-08-21 Last updated: 2017-08-21
Johansson, J., Akbarian-Tefaghi, L., Harith, A., Zrinzo, L., Limousin, P., Joyce, E., . . . Foltynie, T. (2017). Estimation of effective target area in the globus pallidus during deep brain stimulation for Tourette syndrome.. In: : . Paper presented at World Society for Stereotactic and Functional Neurosurgery, 17th Quadrennial meeting, Berlin June 26-29, 2017.
Open this publication in new window or tab >>Estimation of effective target area in the globus pallidus during deep brain stimulation for Tourette syndrome.
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2017 (English)Conference paper, Oral presentation only (Refereed)
National Category
Medical Engineering
Identifiers
urn:nbn:se:liu:diva-139858 (URN)
Conference
World Society for Stereotactic and Functional Neurosurgery, 17th Quadrennial meeting, Berlin June 26-29, 2017
Available from: 2017-08-17 Created: 2017-08-17 Last updated: 2017-08-17
Shah, A., Alonso, F., Lemarie, J.-J., Pison, D., Coste, J., Wårdell, K., . . . Hemm-Ode, S. (2017). Learning more about the optimal anatomical position for deep brain stimulation in essential tremor patients: 3D visualisation of intraoperative stimulation test results. In: : . Paper presented at World Society for Stereotactic and Functional Neurosurgery, 17th Quadrennial meeting, Berlin June 26-29, 2017.
Open this publication in new window or tab >>Learning more about the optimal anatomical position for deep brain stimulation in essential tremor patients: 3D visualisation of intraoperative stimulation test results
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2017 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

INTRODUCTION

The outcome of deep brain stimulation (DBS) depends heavily on the position of the implanted lead. After a preoperative anatomical planning, most groups collect numerous intraoperative data such as therapeutic effects induced by stimulation tests. To choose the final implant position, physicians “mentally” visualise all available data. The aim of the present work was to develop a method visualising intraoperative stimulation test results, patient’s images, electric field (EF) simulations for the patient-specific stimulation conditions and the corresponding therapeutic effects quantitatively evaluated by accelerometry. The application to five essential tremor (ET) patients should give a first idea about the optimal target position. 

METHODS

In Clermont-Ferrand University Hospital the anatomic target structure and the neighbouring structures were manually outlined, a target and a trajectory defined and two parallel trajectories per hemisphere intraoperatively evaluated. Stimulation tests were performed at 7 to 8 positions per trajectory and several stimulation current amplitudes. The therapeutic effect was evaluated using a previously published method based on accelerometry. Finite element models and simulations were performed for up to three stimulation amplitudes per position and EF isosurfaces (0.2V/mm) were extracted. For the 3D visualization of the numerous overlapping isosurfaces, we generated “improvement maps” by assigning to each voxel within the isosurfaces the highest tremor improvement. Those maps were visualized together with anatomical images, delineated structures and trajectories (Paraview, Kitware Inc). The method was applied to 5 ET patients implanted in the ventro-intermediate nucleus of the thalamus (VIM). Results were analysed by the neurosurgeon regarding the optimal implant position.  

RESULTS

The clinical teams were able to identify the optimal implant position for all patients with more ease and in less time compared to the routine discussion using pen and paper. Additionally, for 7 of the 9 improvement maps, the highest improvement region was found to be in the posterior subthalamic area, inferior and posterior to the VIM.

CONCLUSION

Improvement maps assist the clinicians in determining the optimal implant location of the chronic DBS lead. Results support findings of other studies that the fibre tracts in the posterior subthalamic area like prelemniscal radiations may be responsible for alleviating tremor in ET patients.

National Category
Medical Engineering
Identifiers
urn:nbn:se:liu:diva-139878 (URN)
Conference
World Society for Stereotactic and Functional Neurosurgery, 17th Quadrennial meeting, Berlin June 26-29, 2017
Available from: 2017-08-21 Created: 2017-08-21 Last updated: 2017-08-21
Zsigmond, P., Hemm-Ode, S. & Wårdell, K. (2017). Optical Measurements during Deep Brain Stimulation Lead Implantation: Safety Aspects.. Stereotactic and Functional Neurosurgery, 95(6), 392-399
Open this publication in new window or tab >>Optical Measurements during Deep Brain Stimulation Lead Implantation: Safety Aspects.
2017 (English)In: Stereotactic and Functional Neurosurgery, ISSN 1011-6125, E-ISSN 1423-0372, Vol. 95, no 6, p. 392-399Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Intracerebral hemorrhage (ICH) is the most feared complication in deep brain stimulation (DBS) surgery. The aim of the study was to evaluate patient safety and outcome using laser Doppler flowmetry (LDF) as guidance tool during DBS implantations.

METHODS: An LDF probe adapted for the stereotactic system was used as guide for creation of the trajectory. The microcirculation along 83 preplanned trajectories was measured with the guide during DBS surgery for movement disorders. The microvascular blood flow levels were investigated for all measurement positions. Medical record and postoperative radiology were retrospectively reviewed.

RESULTS: Of 2,963 measurement positions, 234 (7.9%) showed at least a doubled blood flow compared to the surrounding tissue. Of these 2.2% had a more than 5 times higher blood flow in front of the probe tip. Along 1 trajectory, a small ICH was detected during surgery. Increased blood flow was more common close to sulci and verticals.

CONCLUSION: Real-time LDF measurement of the microcirculation using a forward-looking probe during DBS surgery can detect blood flow peaks and further minimize the risk of developing ICH. No separate guide tube is necessary as the probe also creates the trajectory for the DBS lead.

Place, publisher, year, edition, pages
Basel: S. Karger, 2017
Keywords
Deep brain stimulation, Intracerebral hemorrhage, Laser Doppler flowmetry, Safety
National Category
Medical Engineering
Identifiers
urn:nbn:se:liu:diva-144203 (URN)10.1159/000484944 (DOI)000426220600005 ()29301132 (PubMedID)
Note

Funding agencies: Swedish Research Council [621-2013-6078]; Parkinson Foundation at Linkoping University

Available from: 2018-01-10 Created: 2018-01-10 Last updated: 2018-03-21
Wårdell, K. (2017). Optical Techniques for Monitoring in Neurosurgery. In: : . Paper presented at 2nd international conference, Biophotonics, Riga 27-29/8 2017.
Open this publication in new window or tab >>Optical Techniques for Monitoring in Neurosurgery
2017 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Medical Engineering
Identifiers
urn:nbn:se:liu:diva-140151 (URN)
Conference
2nd international conference, Biophotonics, Riga 27-29/8 2017
Available from: 2017-09-01 Created: 2017-09-01 Last updated: 2017-09-01
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-0012-7867

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