Application of Neuronavigation in Brain Surgery

Morden Neurosurgery explained in details about the localization of Brain tumour by Neuronavigation

1. Application of Neuronavigation in Brain Surgery Dr Fakir Mohan Sahu MBBS, MS, MCh SR Neurosurgery AIIMS Bhubaneswar 10/10/2020

2. Learning Objectives What is Neuronavigation ? Historical Prospects General Principle- Frame based & Frameless system Application-Anatomical & Functional Indication, Contraindication Advantage, Disadvantage Future Prospects

3. Neuronavigation Set of computer-assisted technologies used by neurosurgeons To guide or "navigate” within the confines of the skull or vertebral column during surgery “ Neuronavigator ” - set of hardware for these purposes

4. History of Navigation

5. Evolution of intraoperative Imaging modalities Radiography: Plain X-ray- Roentgen (1895) Ventriculography: Dandy (1918) Cerebral Angiography: Egas Moniz (1927) Ultrasonography: Ian Donald (1956) CT Scan: Hounsfield (1973) MR imaging : Paul C. Lauterbur (1973) PET/SPECT- Kuhl and Edwards (1963) IMAGE GUIDED NAVIGATION

6. Ventriculography: Dandy (1918)

7. Historical prospects M echanical device for localization of intracranial structures- Zernov ( 1890 ) A pparatus- Encephalometer , used external markers on the head T o calculate the position of intracranial targets. Brain navigation system - pioneers of stereotaxy . ‘Stereotaxic’ (Greek) for ‘three dimensional’ (stereo) and ‘system’ or ‘arrangement’ (taxis). In 1908 Horsley and Clarke - Frame based stereotactic method - Each point in the brain was related to a rigid Cartesian coordinate system . The first Frameless stereotactic system; David Roberts and associates in 1986

8. Horsley and Clarke-1908

9. Frame based system

10. Initial days of target localisation

11. Neuronavigation Frameless System Navigator system with monitor and Localizer Patient reference frame and probe Image data of the patient

12. General Principle Principle- to create virtual linkage between digital image data & real anatomical structures. Technical features include three components: First , the image generation system (CT-scanning or MR imaging) supplying the raw data. Second , the pointer device T hird , the image processing system represented by a high capacity computer work station for data storage and 3D-reconstruction. This procedure optically links the tip of the pointer, presented on the monitor screen, and the displayed image dynamically Shows exact localization either in three perpendicular sectional 2D-views or in a 3D reconstructed image

13. Steps of Navigation

14. Steps of Neuronavigation system Obtaining preoperative image ( Sequential , Non-­‐overlapping volumetric MRI/CT slices, 3D reconstruction) Registration ( ‘image dataset’ with the ‘real time surgical space’.) Point or Surface alignment technique Point technique : Fiducial or Anatomical landmark. (e.g. nasion , external auditory canal, orbital margins) Surface alignment: A Laser beam is used within sight of the optical digitizer to delineate the periorbital and forehead regions of the scalp.

15. Fiducial Fiducia is Latin word meaning – TRUST Navigation is based upon targeting relative to known reference points Bone fiducials like bone screws Skull implanted fiducials Adhesive markers Cranial markers

16. Steps of Neuronavigation system Dynamic Referencing An optical reference frame with passive infrared reflectors is secured to the Mayfield head clamp. The optical digitizers recognize the fixed relationship between the reference frame and the patient’s head. Intraoperative localization Intraoperative control Visualization and Surgery Post surgery evalution

17. Application of Neuronavigation Anatomical applications Tumour localisation (Small to skull base lesion ) Define the tumour margins and the limit of extension Stereotactic Biopsy. Craniotomy guided by stereotaxy . Localizing encased and displaced vascular structures Clipping of intracranial aneurysms . Stereotactic Radiosurgery

18. Application of Neuronavigation Intracranial Endoscopy( more precise planned trajectories ) Stereotactic third ventriculostomy, Colloid cyst removals Pituitary tumour using endoscopy Intracranial Drainage Cystic lesion Abscesses guided by navigation For local antibiotic therapy. Introduction of catheter by navigation Interstitial brachytherapy I ntracranial bleedings for evacuation and lysis therapy

19. Application of Neuronavigation Functional: Surgery for movement disorders – Parkinson’s disease. – Hemiballismus. – Dystonia. – Choreoathetosis. – Intention tremors. – Intractable pain. – Psychosurgery . Placement electrodes Electrode placement – Deep brain stimulation Epilepsy—implantation of depth electrodes.

20. Localization of lesion

21. Stereotactic biopsy for deep seated tumour

22. STB (Stereotactic biopsy) Indication of STB Multiple intracranial masses, (e.g. metastases, inflammatory lesions, lymphomas, multicentric gliomas.) Diffuse ill-defined intra-axial masses. Deep seated intra-axial lesions (thalamic/ hypothalmic gliomas, brainstem lesions) Lesions in eloquent locations, such as the motor or speech areas. Unresectable invasive lesions. Potentially radiosensitive lesions, such as germ cell tumours . Contraindication Suspected vascular lesions. Large lesions with significant mass effect require an open craniotomy and decompression. Altered bleeding parameters. Extra-axial lesions, such as meningioma. Lesions close to the Sylvian fissure, suprasellar region and the third ventricle and most posterior fossa tumours. Complication Haemorrhage. New neurological deficits. Seizures. Infection.

23. Localization of vascular lesion

24. N euronavigation in a patient with 2 metastatic tumors (outlined in purple and pink) , which were removed simultaneously in a single procedure. Metastatic tumour

25. Neuronavigation in a patient with a colloid cyst. The colloid cyst is outlined in pink, the entry point is arked with a green cross, and the foramen of Monro with a red cross. Parallel yellow lines represent the endoscope shaft. Colloid Cyst

26. N euronavigation - a chordoma engaging the clivus and C-1 and C-2 vertebrae. For better visualization of bone and soft tissues, MR images and CT data sets were fused preoperatively. Clival Chordoma

27. N euronavigation in a patient undergoing repeated operation for a pituitary adenoma. The tumor is outlined in yellow and the internal carotid arteries in pink . The red cross is the targeted anterior border of the tumor, most remote of the carotid arteries. Rec. Pituitary Adenoma

28. Stereotactic Radiosurgery A single high dose of focused radiation can be delivered to targets safely sparing normal tissue. Alternative to WBRT

29. Advantages Accurate, safe, Simple, cost effective Lowers the incidence of wound infection Shortens length of hospital stay Reduces the risk for neurological morbidity For Deep seated tumours, complete removal of tumours For saving surroundings brain and vital tissues

30. Disadvantage Neuronavigation errors Expensive Time consuming Delay in calculation, registration Brain shift Local tissue deformation

31. Neuro-­‐navigation errors Image dataset acquisition Overlapping or interspacing slices. Variable slice thickness due to mechanical factors Resolution errors and limitations Errors associated with image fusion algorithms Prevention Careful planning on well maintained equipment

32. Registration error Adverse skin mobility Poor delineation of occipital region in surface mapping models Fiducial movement Prevention Careful placement of Mayfield clamp Combination of surface and point registration Inclusion of the whole head during registration Intraoperative error Parallax type error when planning craniotomy Head movement causing loss of registration Brain shift Small errors in trajectory angle are magnified at the tip of a biopsy needle

33. Brain Shift CSF drainage Use of diuretics Tumor resection which makes an error in the accuracy of the preoperative data. (Deeper st ructures, such as those at the skull base or along the falx shift less than superficial structures) Prevention Displacement is often greatest in the direction of gravity Minimizing diuretic use CSF shunting should be avoided until after the primary approach has been made Defining the outer margins of a tumor before proceeding with debulking

34. Helen Brontë-Stewart, MD, MSE, Stephanie Louie, MS, Sara Batya , MD, Jaimie M Henderson, MD,

35. Recent advances and Future prospects Neuronavigation and Intraoperative MR Imaging (Brain Lab) The MRI functional, diffusion, and perfusion data would constitute a virtual reality view of the brain Can make real-time, intraoperative MR imaging scans available. OT and all its instruments must be made MR imaging compatible Neuronavigation and Intraoperative SPECT and PET Both SPECT and PET imaging techniques require radionuclides E xpenditures, and radiation hazards Introduction into the operating room is actually impossible N ot cost-effective.

36. Recent advances and Future prospects Neuronavigation and Intraoperative Ultrasonography R eal-time imaging Without a radiation burden to the patient. D oes not entail any special requirements on the neurosurgical armamentarium or the environment OT. Cheaper than iCT and especially iMR imaging P roviding the potential for brain shift evaluation and correction I ntraoperative ultrasonography has its place in the neuronavigation of the future. Neuronavigation and Robotics

37. Thank You