Cyberknife Stereotactic Treatment Eugene Lief, Ph.D. Christ Hospital Jersey City, New Jersey USA DISCLAIMER: I am not affiliated with any vendor and did not receive any financial support from any vendor. I am not recommending any particular product.
CyberKnife System
CyberKnife from Accuray, Inc.
Cyberknife Capabilities As a robotic radiosurgery system, the CyberKnife enables to target tumors anywhere in the body with submillimeter accuracy. Autonomous robotic ability to track, detect and correct for tumor and patient movement throughout the treatment Dynamically delivering radiation in sync with real-time tumor motion CyberKnife System provides a pain-free treatment alternative without the use of head and body frames.
Tumor Sites CyberKnife System can treat tumors in: Brain, Spine, Lungs, Liver, Pancreas, Prostate No head and body frames or other immobilization devices. The number of CyberKnife extracranial treatments grew by over 185% between 2004 and 2006..
Growing Popularity
Autonomous Robotics au ton o mous ro bot ics [aw-ton-uh-muhs roh-bot-iks] noun a: an electro-mechanical device capable of making intelligent decisions with limited or no human guidance b: a mechanized tool with the independent ability to respond and react to a dynamic environment based upon sensory input. CyberKnife System allows to track unpredictable tumor motion due to normal bodily functions, such as movement due to digestive functions around the prostate. It tells when the tumor moves even when the patient is stationary. The System shows [in real-time] tumor position from the beginning to the end of the treatment and automatically corrects for tumor movement.
Continuous Image Guidance Without the need for staff intervention or treatment interruption, the CyberKnife System continuously works in concert with the treatment delivery system to instantly track, detect and correct managing possible target movements throughout the treatment.
Flexible Robotic Maneuverability Driven by continual imaging and intelligent movement corrections, the CyberKnife s robotic manipulator automatically places the linear accelerator to a wide possible range of positions allowing access to any tumor from multiple directions
Dynamic Motion Targeting With constant updates of target position throughout the respiratory cycle, the beams are synchronized in realtime to the target position while adapting to changes in breathing patterns delivering highly conformal radiation with small margins and high accuracy.
Intelligent Patient Positioning The robotic patient positioning system automatically moves the patient to the exact treatment position with immediate accuracy providing greater setup precision while significantly streamlining the patient setup process.
Room Setup
4D Treatment Optimization and Planning System Takes into account not only the movement of the target but also the movement and deformation of the surrounding tissue.
Xchange Robotic Collimator Changer Automatically exchanges collimators robotically, maintaining highly efficient treatment process
Xsight Lung Tracking System Tracks the movement of lung tumors directly without fiducials, with precision, reliability and self-adjusting repeatability.
Synchrony Respiratory Tracking System Continuously synchronizes beam delivery to the motion of the tumor, allowing to significantly reduce margins while eliminating the need for gating or breath-holding techniques.
RoboCouch Patient Positioning System Robotically aligns patients precisely with six degrees of freedom, reducing patient setup times and enabling faster treatments.
X-ray Sources The low-energy X-ray sources generate orthogonal images to determine the location of bony landmarks, implanted fiducials or soft tissue targets throughout the entire treatment.
Image Detectors The flush mounted detectors capture high-resolution anatomical images throughout the treatment. These live images are continually compared to previously captured DRR s to determine real-time patient positioning and target location. Based on this information, the robotic manipulator instantly corrects for any detected movement.
Robotic Manipulator The high precision robotic manipulator capable of delivering repeatable submillimeter accuracy, positions the linear accelerator in almost any direction providing non-coplanar and non-isocentric beam delivery.
This compact, light weight 6MV X-ray linear accelerator with an output of 600 MU/min, precisely delivers highly collimated beams of radiation, providing superior conformality Linear Accelerator
MultiPlan Treatment Planning System This intuitive workflow-based workstation designed for radiosurgery, enables the creation of plans that have high conformality and coverage with steep dose gradients.
Radiosurgery vs. Radiotherapy Average Dose Per Fraction Typical # of Fractions Typical # of Unique Beams Per Fraction Typical Targeting Accuracy Clinical Intent Radiosurgery High dose (~ 6 to 25 Gy per fraction) 1 5 fractions 150 200 < 1 millimeter Tumor ablation Radiotherapy Low dose (~ 2 Gy per fraction) 30 45 fractions 5 10 3 20 millimeters Cumulative dose tumor control
Dose Escalation for Tumor Ablation Necessitates: Extreme Targeting Accuracy Ability to deliver sub-millimeter mechanical accuracy Ability to deliver sub-millimeter tumor targeting accuracy Large Non-Coplanar Beam Delivery Ability to diversify beam trajectories to reduce risks of dose toxicity Agility to target tumors from a high volume of unique angles
Radiation Delivery System Comparison Radiation Therapy Systems Targeting Accuracy Applications Ability to Fractionate Image Guidance 5 20 millimeters Intracranial and Extracranial Unlimited Typically limited to MV portal imaging on a weekly basis Varian Clinac Elekta Synergy Siemens PRIMUS TomoTherapy Hi-ART System Non- Coplanar Delivery Capabilities Limited clockwise / counter-clockwise gantry mobility enables a single plane typically delivering 7 unique beam angles Additional planes can be achieved with manual couch yaw rotations. Patient / gantry collision potential and the impractical nature of manual patient positioning has resulted in little or no clinical adoption Moving Tumor Targeting Stereotactic Frames Utilizes gating / breath-holding techniques resulting in large contour margins and unnecessary healthy tissue exposure Immobilization devices used. Low dose per fraction reduces need for accuracy
Radiation Delivery System Comparison Radiation Therapy Systems Radiation Therapy Systems Adapted for Radiosurgery Targeting Accuracy Applications 5 20 millimeters Intracranial and Extracranial 3 20 millimeters Intracranial and Extracranial Varian Trilogy Elekta Axesse BrainLAB Novalis Ability to Fractionate Unlimited Unlimited Image Guidance Typically limited to MV portal imaging on a weekly basis Image guidance limited to pretreatment, patient set-up only High resolution kv imaging / conebeam CT Non- Coplanar Delivery Capabilities Limited clockwise / counter-clockwise gantry mobility enables a single plane typically delivering 7 unique beam angles Additional planes can be achieved with manual couch yaw rotations. Patient / gantry collision potential and the impractical nature of manual patient positioning has resulted in little or no clinical adoption Limited clockwise / counter-clockwise gantry mobility enables a single plane typically delivering 7 unique beam angles Additional planes can be achieved with manual couch yaw rotations, however without image guidance due to patient / OBI collisions - resulting in less than ideal targeting accuracy. Further, the impractical nature of manual patient positioning has resulted in little or no clinical adoption Moving Tumor Targeting Utilizes gating / breath-holding techniques resulting in large contour margins and unnecessary healthy tissue exposure Utilizes gating / breath-holding techniques resulting in large contour margins and unnecessary healthy tissue exposure Stereotactic Frames Immobilization devices used. Low dose per fraction reduces need for accuracy Required in most Intracranial & Extracranial cases
Radiation Delivery System Comparison Targeting Accuracy Applications Ability to Fractionate Radiation Therapy Systems 5 20 millimeters Unlimited Radiation Therapy Systems Adapted for Radiosurgery 3 20 millimeters Elekta Gamma Knife Elekta Intracranial Perfexion and Extracranial American Radiosurgery GammaART-6000 6000 Intracranial and Extracranial Unlimited Dedicated Cobalt 60 Radiosurgery Systems < 1 millimeter Intracranial only Limited spine capabilities (C1 & C2) Perfexion only Typically limited to a single fraction due to time, resource, and pain constraints Image Guidance Typically limited to MV portal imaging on a weekly basis Image guidance limited to pretreatment, patient set-up only High resolution kv cone-beam CT None, relies exclusively on target s fixed relative position to the stereotactic frame Frame mechanical accuracy may introduce 1.2-1.9 mm error (*Maciunas) Non- Coplanar Delivery Capabilities Limited clockwise / counter-clockwise gantry mobility enables a single plane typically delivering 7 unique beam angles Additional planes can be achieved with manual couch yaw rotations. Patient / gantry collision potential and the impractical nature of manual patient positioning has resulted in little or no clinical adoption Limited clockwise / counter-clockwise gantry mobility enables a single plane typically delivering 7 unique beam angles Additional planes can be achieved with manual couch yaw rotations, however without image guidance due to patient / OBI collisions - resulting in less than ideal targeting accuracy. Further, the impractical nature of manual patient positioning has resulted in little or no clinical adoption Hemisphere with fixed collimators enables a non-coplanar workspace capable of delivering a maximum of 201 (190 Perfexion ) unique beam angles Moving Tumor Targeting Utilizes gating / breath-holding techniques resulting in large contour margins and unnecessary healthy tissue exposure Utilizes gating / breath-holding techniques resulting in large contour margins and unnecessary healthy tissue exposure N/A Stereotactic Frames Immobilization devices used. Low dose per fraction reduces need for accuracy Required in most Intracranial & Extracranial cases * RJ Maciunas, RL Galloway Jr, JW Latimer. The application accuracy of stereotactic frames. Neurosurgery 35(4): 682 695, Oct 1994 Requires invasive frames in all cases
Radiation Delivery System Comparison Radiation Therapy Systems Radiation Therapy Systems Adapted for Radiosurgery Dedicated Cobalt 60 Radiosurgery Systems Dedicated Robotic Radiosurgery Systems Targeting Accuracy Applications 5 20 millimeters Intracranial and Extracranial 3 20 millimeters Intracranial and Extracranial < 1 millimeter Accuray Incorporated CyberKnife System Intracranial only Limited spine capabilities (C1 & C2) Perfexion only < 1 millimeter for stationary tumors < 1.5 millimeters for moving tumors Intracranial and Extracranial Ability to Fractionate Unlimited Unlimited Typically limited to a single fraction due to time, resource and pain constraints Unlimited Image Guidance Non-Coplanar Delivery Capabilities Typically limited to MV portal imaging on a weekly basis Limited clockwise / counter-clockwise gantry mobility enables a single plane typically delivering 7 unique beam angles Additional planes can be achieved with manual couch yaw rotations. Patient / gantry collision potential and the impractical nature of manual patient positioning has resulted in little or no clinical adoption Image guidance limited to pretreatment, patient set-up only High resolution kv imaging / conebeam CT Limited clockwise / counterclockwise gantry mobility enables a single plane typically delivering 7 unique beam angles Additional planes can be achieved with manual couch yaw rotations, however without image guidance due to patient / OBI collisions - resulting in less than ideal targeting accuracy. Further, the impractical nature of manual patient positioning has resulted in little or no clinical adoption None, relies exclusively on target s fixed relative position to the stereotactic frame Frame mechanical accuracy may introduce 1.2-1.9 mm error (*Maciunas) Hemisphere with fixed collimators enables a non-coplanar workspace capable of delivering a maximum of 201 (190 Perfexion ) unique beam angles Continual image guidance throughout the treatment High resolution kv imaging Automatically track, detect and correct for tumor and patient movement Robotic mobility enables a large non-coplanar workspace capable of seamlessly delivering more than 1200 unique beam angles without treatment interruption or the need to manually reposition the patient Moving Tumor Targeting Utilizes gating / breath-holding techniques resulting in large contour margins and unnecessary healthy tissue exposure Utilizes gating / breath-holding techniques resulting in large contour margins and unnecessary healthy tissue exposure N/A Delivers tightly contoured beams synchronized precisely to tumor motion resulting in minimal healthy tissue exposure Stereotactic Frames Immobilization devices used. Low dose per fraction reduces need for accuracy Required in most Intracranial & Extracranial cases Requires invasive frames in all cases No frame required * RJ Maciunas, RL Galloway Jr, JW Latimer. The application accuracy of stereotactic frames. Neurosurgery 35(4): 682 695, Oct 1994
Multi-Plan TPS An intuitive workflow-based treatment planning software designed for radiosurgery Enables excellent conformality and coverage with steep dose gradients. Using images from multiple modalities, including CT, MR, PET and 3D Rotational Angiography. Up to four image sets including a reference CT, up to three additional CT, MR, PET and/or 3D Rotational Angiography image sets. Supports image sets in axial, sagittal, coronal and oblique orientations. Fusion is performed automatically using a normalized mutual information based algorithm or manually using anatomical and other reference the user to verify the quality of the registration result.
Planning Templates
Delineate Volumes for Tracking
Approve Beam Data
Select Planning Options
Evaluating and Finalizing the Plan
Introducing Small Changes
Simplified Contouring Create customized planning templates that can be used when delineating volumes of interest (VOI) on any displayed 2D planes (axial, sagittal or coronal) using fused image sets. Delineation includes basic tools, such as drawing and bumper tools, and advanced tools such as Magic Wand and Smart Curve. Use these and other tools to delineate multiple structures in a single VOI (e.g.cavities and bifurcated structures). Other tools enable generation of anisotropic volume expansion and tuning structures with just a few mouse clicks.
Plan Optimization Choose the appropriate tracking option 6D Skull Tracking, Fiducial Tracking, Synchrony Respiratory Tracking, Xsight Spine TrackingSystem or the Xsight Lung Tracking System Set dose constraints to create an optimized treatment plan using forward or inverse planningtechniques and a choice of powerful optimization algorithms.
Once a Plan is Generated View isocontours on every slice in every plane; view and interrogate the dose volume histogram (DVH) for the target and for each critical structure Select 4D optimization tools to account for tissue deformation in lung treatments Review plan statistics, such as conformality and homogeneity indices, and 3D representations of the beam and patient geometry Visualize the actual treatment delivery in action Select beams singly or in groups and manually modify any treatment parameter Compare high resolution plans side-by-side to determine which provides the best treatment for the patient
QA and Commissioning Ability to create QA plans for end-to-end testing of the CyberKnife Phantom overlay of individual treatment plans for plan QA Ability to export a treatment beam parameter list, enabling patient specific manual dose calculation checks The ability to view and approve beam data that is stored in the CyberKnife database prior to using this data to generate plans DICOM inter faces: Import and Export DICOM Image series Import and Export DICOM RT Structure Set Export DICOM RT Dose