Cyberknife At Saint Raphael’s Campus_revB

Download Cyberknife At Saint Raphael’s Campus_revB

Post on 17-Aug-2015

26 views

Category:

Documents

2 download

Embed Size (px)

TRANSCRIPT

  1. 1. CYBERKNIFE At Saint Raphaels Campus Presented by: Justin Vinci M.S. DABR
  2. 2. SUMMARY Cyberknife System Overview Cyberknife Concept Cyberknife Components Cyberknife Experience at SRC Tracking Modalities Collimation Fixed Stereotactic Cones IRIS Variable aperture Treatment Planning Optimization Dose Calculation Physics QA
  3. 3. CYBERKNIFE SYSTEM OVERVIEW Cyberknife Concept Robotic Radiosurgery System Non-coplanar beam arrangement Theoretically able to achieve a better treatment plan Conformality Homogeneity Critical structure avoidance Stereotactic alignment accuracy Room based stereotactic kV X-ray imaging system < 1 mm targeting accuracy Inter and Intrafraction Motion Management kV X-rays taken throughout treatment Synchrony respiratory motion tracking
  4. 4. CYBERKNIFE SYSTEM OVERVIEW Cyberknife Components Manipulator KUKA robot with 6 axes of rotation < 0.2 mm Mechanical precision Manual control with teach pendant Programmable robot positions Linac 6 MV No flattening filter Dose Rate = 800 cGy/Min Sealed ion chambers (since 2010) Collimation system 12 Fixed cones or IRIS variable collimator Collimator exchange table
  5. 5. CYBERKNIFE SYSTEM OVERVIEW Cyberknife Components Robocouch 6 degrees of motion kV X-ray Target Location System Floor mounted flat panel imagers Perkin Elmer ASi panels 1024 x 1024 pixels 41 x 41 cm physical dimensions Ceiling mounted X-ray tubes Oil cooled 2.5 mm Al filtration up to 125 kV, 320 mA, 500 ms Synchrony Respiratory Tracking System Ceiling mounted LED camera array Treatment Planning System Multi-Plan V3.5
  6. 6. CYBERKNIFE SYSTEM OVERVIEW
  7. 7. CYBERKNIFE SYSTEM OVERVIEW Treatment Paths Site dependent Set of nodes Nodes Positions where the robot stops in robotic workspace 12 beams per node. (12 angles) Head 1pathhead (130 nodes, 800 SAD) Shortpath (69nodes, 800 SAD) Trigeminal (117 nodes, 650-750 SAD) Body 1pathbody (117 nodes, 900-1000 SAD) ShortpathBody(62 nodes, 900-1000 SAD) Prostate path (114 nodes, 900-1000 SAD)
  8. 8. CYBERKNIFE SYSTEM OVERVIEW Isocentric Beam Treatment Non-coplanar beam treatment to a single target coordinate Small spherical lesions
  9. 9. CYBERKNIFE SYSTEM OVERVIEW Conformal Beam Treatment Non-isocentric Dose Painting delivery Multiple target coordinates
  10. 10. CYBERKNIFE SYSTEM OVERVIEW
  11. 11. CYBERKNIFE EXPERIENCE AT SRC Installed May 2008 Re-commissioned 2010 with IRIS upgrade Total Intracranial Patients Treated 466 Total Extracranial Patients Treated 272 TOTAL PATIENTS TREATED 738
  12. 12. CYBERKNIFE EXPERIENCE AT SRC Installed May 2008 Re-commissioned 2010 with IRIS upgrade AVM/AVOM 1 Breast Met to Brain 41 Trigeminal Neuralgia 62 Renal Met to Brain 12 Vestibular Schwannoma 39 Colon Met to Brain 8 Meningioma 85 Melanoma Met to Brain 6 Pituitary Adenoma 18 Ovarian Met to Brain 1 Glioblastoma 15 Other Metastatic Tumor to Brain 14 Craniopharyngioma 1 Glomus Tumor 3 Hemangioblastoma 2 Astrocytoma/Glioma/GBM 4 Schwannoma 8 Oligodendroglioma/Medulloblastoma 3 Other/Vas/Func Benign Tumors 1 Other Glial Tumors/Other/Unknown 1 Lung Met to Brain 141 Total Intracranial Patients Treated 466 Data Intracranial (5/2008 2/2013)
  13. 13. CYBERKNIFE EXPERIENCE AT SRC Data Extracranial C-spine 8 T-spine 36 L/S-spine 15 Lung 87 Liver 15 Pancreas 5 Head/Neck/ENT 12 Prostate 67 Nasopharynx 1 Other 26 Total Extracranial Patients Treated 272
  14. 14. TRACKING MODALITIES 6D Skull Cranial Lesions Brain Mets Trigeminal Neuralgia Benign Meningiomas Fiducial Tracking Body Prostate Synchrony Fiducial Tracking with respiratory motion correction Lung, Liver X-sight Spine S,L,T,C Spine Anything < 5 cm from spine X-sight Lung Lesions >1.5 cm in periphery of lung
  15. 15. 6D SKULL Alignment center is always set to the center of the skull Library of 33 pairs of DRRs generated about alignment center 6D correction determined from comparison between live X-rays and DRRS Similarity measure and rigid transformation based on bony anatomy Fu et al.: A fast, accurate, and automatic 2D-3D image registration for image-guided cranial radiosurgery, Med. Phys. 35 (5), May 2008
  16. 16. 6D SKULL 6D couch correction is calculated based on kV X- rays Robocouch couch automatically moves to the correct position The Cyberknife robot adjusts beam targeting during treatment based intra-fraction images (limits: 10 mm, 1.5 degrees)
  17. 17. FIDUCIAL TRACKING Several fiducials surgically implanted in or nearby the tumor 6D tracking requires at least 3 fiducials 20 mm separation, 15, non-co-linear, < 5 cm from target We typically use 0.8 x 3 mm coupled gold markers 18 gauge needle Fiducials are identified on the CT in MultiPlan and used for alignment
  18. 18. FIDUCIAL TRACKING Blobs are Identified in live X-ray images and compared to a library of DRRs from the reference CT using a fiducial based image registration methodology Intensity thresholds set to live images to bring out blobs Set of blobs is refined based on expected shape, size, etc. Ranked by likelyhood Refine by Inferior Superior location Blobs with the same I-S position = Same source Backward project from 2D to 3D space All potential fiducial configuration candidates compared to the reference fiducial configuration from the CT Configurations are ranked and the best fit is used for alignment Saw et al.: Implementation of fiducial-based image registration in the Cyberknife robotic system, Med Dos. 33 (2), 2008
  19. 19. FIDUCIAL TRACKING 3 or more fiducial markers are placed inside the tumor with adequate separation Fiducial pattern is recognized by the Cyberknife imaging system. Marker locations in the Live X-ray images are compared to expected locations. The robotic couch automatically repositions the patient. The Cyberknife makes 6D (X,Y,Z; ,,) corrections to beam targeting using a rigid transformation algorithm Live X-ray images taken during the treatment allows for semi-continuous monitoring of intra-fraction motion (when not using Synchrony)
  20. 20. FIDUCIAL TRACKING Fiducial Tracking Parameters Rigid-body distance threshold 1.5 mm Fiducial spacing threshold 20.0 mm Colinearity Threshold 15.0 X-Axis Pairing Tolerance 2.5 mm Confidence Threshold 60 % Tracking Range 40 mm
  21. 21. SYNCHRONY Fiducial positions tracked at discrete points in time LED Markers monitored in real time by a camera system Synchrony establishes a correlation between external and internal moments Robot adjusts beam based on Synchrony model (translations only)
  22. 22. SYNCHRONY Breathing Trace Correlation Graphs Coverage of Breathing Cycle Correlation Error Graph Nioutsikou et al.: Dosimetric investigation of lung tumor motion compensation with a robotic respiratory tracking system: An experimental study, Med. Phys. 35 (4), April 2008 Pepin et al.: Correlation and prediction uncertainties in the Cyberknife Synchrony respiratory tracking system, Med. Phys. 38 (7), July 2011
  23. 23. SYNCHRONY
  24. 24. XSIGHT SPINE Inherent problems aligning spinal anatomy: Vertebrae can move independent of one another Rigid transformation may be invalid Risks associated with surgical fiducial placement Xsight spine solution: Deformable registration technique for spine alignment
  25. 25. XSIGHT SPINE Image enhancement Enhance skeletal structures, suppress soft tissue DRR generation (17 pairs of DRRs) ROI placement Maximum bone information Skeletal mesh overlayed on spine 2D-3D registration Spatial transformation base on similarity measure Local displacement field calculated at each node (81) 3D target location calculated Maucevic et al.: Technical description, phantom accuracy, and clinical feasibility for fiducial free frameless real-time image guided spinal radiosurgery, J. Neurosurg Spine, 5 October 2006 Furweger et al.: Advances in fiducial-free image-guidance for spinal radiosurgery with Cyberknife a phantom study, J. Applied Clinical Med. Phys. 12, (2), Spring 2011
  26. 26. XSIGHT SPINE Difference in spinal anatomy detected between acquired Live X- ray images and planned DRR images 6D Treatment Couch corrections (X,Y,Z; ,,) are applied for initial setup. The Cyberknife robot adjusts beam targeting during treatment based intra-fraction images
  27. 27. XSIGHT LUNG Fiducial-less lung tumor tracking Tracking based on imaging of the lesion directly Patient Selection Target > 15 mm in each axis Peripherally located Not obstructed by skeletal structures Tracking volume is contoured for a visual reference Synchrony used for respiratory tracking
  28. 28. XSIGHT LUNG Fiducial-less lung tumor tracking Tracking based on imaging of the lesion directly Patient Selection Target > 15 mm in each axis Peripherally located Not obstructed by skeletal structures Tracking volume is contoured for a visual reference Synchrony used for respiratory tracking
  29. 29. XSIGHT LUNG Fiducial-less lung tumor tracking Tracking based on imaging of the lesion directly Patient Selection Target > 15 mm in each axis Peripherally located Not obstructed by skeletal structures Tracking volume is contoured for a visual reference Synchrony used for respiratory tracking
  30. 30. XSIGHT LUNG Initial patient alignment with Xsight spine go to Xsight Lung Robocouch moves to align to target Visually confirm that the system truly detects lesion Build a Synchrony respiratory correlation model Begin Treatment Cyberknife adjusts beam targeting during treatment based on Synchrony and intra-fraction images
  31. 31. COLLIMATION TYPES Stereotactic cone sizes: 5, 7.5, 10, 12.5, 15 20, 25, 30, 35, 40, 50, 60 mm (defined at 80 cm) Variable aperture sizes: 5, 7.5, 10, 12.5