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 sub- millimeter 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 real- time 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 sub- millimeter accuracy, positions the linear accelerator in almost any direction providing non-coplanar and non-isocentric beam delivery. Linear Accelerator

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 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

Radiosurgery Radiotherapy Average Dose Per High dose Low dose Fraction (~ 6 to 25 Gy per (~ 2 Gy per fraction) fraction) Typical # of 1 – 5 fractions 30 – 45 fractions Fractions

Typical # of Unique 150 – 200 5 – 10 Beams Per Fraction

Typical Targeting < 1 millimeter 3 – 20 millimeters Accuracy

Clinical Intent Tumor ablation 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

5 – 20 millimeters Targeting Varian Clinac® Accuracy Elekta Synergy® Intracranial and Extracranial Applications Siemens PRIMUS® TomoTherapy Hi-ART System®

Ability to Unlimited Fractionate Image Typically limited to MV portal imaging on a weekly basis Guidance

Non- Limited clockwise / counter-clockwise gantry mobility enables a single plane Coplanar typically delivering 7 unique beam Delivery angles Capabilities • 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 Utilizes gating / breath-holding techniques resulting in large contour Tumor margins and unnecessary healthy Targeting tissue exposure

Stereotactic Immobilization devices used. Low dose per fraction reduces need for Frames accuracy Radiation Delivery System Comparison

Radiation Therapy Systems Radiation Therapy Systems Adapted for Radiosurgery Targeting 5 – 20 millimeters 3 – 20 millimeters Accuracy Varian Trilogy™ Applications Intracranial and Extracranial Intracranial and Extracranial Elekta Axesse™ BrainLAB Novalis®

Ability to Unlimited Unlimited Fractionate Image Typically limited to MV portal imaging Image guidance limited to pre- on a weekly basis treatment, patient set-up only Guidance • High resolution kV imaging / cone- beam CT

Non- Limited clockwise / counter-clockwise Limited clockwise / counter-clockwise gantry mobility enables a single plane gantry mobility enables a single plane Coplanar typically delivering 7 unique beam typically delivering 7 unique beam Delivery angles angles Capabilities • Additional planes can be achieved • Additional planes can be achieved with manual couch yaw rotations. with manual couch yaw rotations, Patient / gantry collision potential and however without image guidance due the impractical nature of manual to patient / OBI collisions - resulting in patient positioning has resulted in less than ideal targeting accuracy. little or no clinical adoption Further, the impractical nature of manual patient positioning has resulted in little or no clinical adoption

Moving Utilizes gating / breath-holding Utilizes gating / breath-holding techniques resulting in large contour techniques resulting in large contour Tumor margins and unnecessary healthy margins and unnecessary healthy Targeting tissue exposure tissue exposure

Stereotactic Immobilization devices used. Low Required in most Intracranial & dose per fraction reduces need for Extracranial cases Frames accuracy Radiation Delivery System Comparison

Radiation Therapy Systems Dedicated Cobalt 60 Radiation Therapy Systems Adapted for Radiosurgery Radiosurgery Systems Targeting 5 – 20 millimeters 3 – 20 millimeters < 1 millimeter Accuracy Elekta Gamma Knife® Elekta Perfexion™ Applications Intracranial and Extracranial Intracranial and Extracranial Intracranial only American Radiosurgery GammaART-6000™ • Limited spine capabilities (C1 & C2) Perfexion™ only Ability to Unlimited Unlimited Typically limited to a single fraction due to time, resource, and pain Fractionate constraints

Image Typically limited to MV portal imaging Image guidance limited to pre- None, relies exclusively on target’s on a weekly basis treatment, patient set-up only fixed relative position to the Guidance stereotactic frame • High resolution kV cone-beam CT • Frame mechanical accuracy may introduce 1.2-1.9 mm error (*Maciunas)

Non- Limited clockwise / counter-clockwise Limited clockwise / counter-clockwise Hemisphere with fixed collimators gantry mobility enables a single plane gantry mobility enables a single plane enables a non-coplanar workspace Coplanar typically delivering 7 unique beam typically delivering 7 unique beam capable of delivering a maximum of Delivery angles angles 201 (190 Perfexion™) unique beam angles Capabilities • Additional planes can be achieved • Additional planes can be achieved with manual couch yaw rotations. with manual couch yaw rotations, Patient / gantry collision potential and however without image guidance due the impractical nature of manual to patient / OBI collisions - resulting in patient positioning has resulted in less than ideal targeting accuracy. little or no clinical adoption Further, the impractical nature of manual patient positioning has resulted in little or no clinical adoption

Moving Utilizes gating / breath-holding Utilizes gating / breath-holding N/A techniques resulting in large contour techniques resulting in large contour Tumor margins and unnecessary healthy margins and unnecessary healthy Targeting tissue exposure tissue exposure

Stereotactic Immobilization devices used. Low Required in most Intracranial & Requires invasive frames in all cases dose per fraction reduces need for Extracranial cases Frames accuracy * RJ Maciunas, RL Galloway Jr, JW Latimer. The application accuracy of stereotactic frames. Neurosurgery 35(4): 682–695, Oct 1994 Radiation Delivery System Comparison

Radiation Therapy Systems Adapted Dedicated Robotic Radiosurgery Radiation Therapy Systems Dedicated Cobalt 60 Radiosurgery Systems for Radiosurgery Systems

Targeting 5 – 20 millimeters 3 – 20 millimeters < 1 millimeter < 1 millimeter for stationary Accuracy Accuray Incorporated tumors ® CyberKnife System < 1.5 millimeters for moving tumors Applications Intracranial and Extracranial Intracranial and Extracranial Intracranial only Intracranial and Extracranial • Limited spine capabilities (C1 & C2) Perfexion™ only Ability to Unlimited Unlimited Typically limited to a single fraction due Unlimited Fractionate to time, resource and pain constraints

Image Guidance Typically limited to MV portal imaging Image guidance limited to pre- None, relies exclusively on target’s fixed Continual image guidance on a weekly basis treatment, patient set-up only relative position to the stereotactic throughout the treatment frame • High resolution kV imaging / cone- • High resolution kV imaging beam CT • Frame mechanical accuracy may introduce 1.2-1.9 mm error (*Maciunas) • Automatically track, detect and correct for tumor and patient movement Non-Coplanar Limited clockwise / counter-clockwise Limited clockwise / counter- Hemisphere with fixed collimators Robotic mobility enables a large Delivery gantry mobility enables a single plane clockwise gantry mobility enables a enables a non-coplanar workspace non-coplanar workspace capable Capabilities typically delivering 7 unique beam single plane typically delivering 7 capable of delivering a maximum of 201 of seamlessly delivering more angles unique beam angles (190 Perfexion™) unique beam angles than 1200 unique beam angles without treatment interruption or • Additional planes can be achieved • Additional planes can be achieved the need to manually reposition with manual couch yaw rotations. with manual couch yaw rotations, the patient Patient / gantry collision potential and however without image guidance the impractical nature of manual due to patient / OBI collisions - patient positioning has resulted in little resulting in less than ideal targeting or no clinical adoption accuracy. Further, the impractical nature of manual patient positioning has resulted in little or no clinical adoption

Moving Tumor Utilizes gating / breath-holding Utilizes gating / breath-holding N/A Delivers tightly contoured beams Targeting techniques resulting in large contour techniques resulting in large contour synchronized precisely to tumor margins and unnecessary healthy margins and unnecessary healthy motion resulting in minimal tissue exposure tissue exposure healthy tissue exposure

Stereotactic Immobilization devices used. Low dose Required in most Intracranial & Requires invasive frames in all cases No frame required Frames per fraction reduces need for accuracy Extracranial cases

* 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