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Joint Imaging-Therapy SymposiumImaging, Guidance, and New Technologies
in IG Interventions
Joint Imaging-Therapy SymposiumImaging, Guidance, and New Technologies
in IG Interventions
Jeff Siewerdsen, PhDDepartment of Biomedical Engineering
Johns Hopkins University
David Hawkes, PhDUniversity College
London UK
Paul Keall, PhDDepartment of Radiation Oncology
Stanford University
DQE ���� FDK ���� TREThese and Other TLAs in the Development
of New Technologies for Image-Guided Surgery
DQE ���� FDK ���� TREThese and Other TLAs in the Development
of New Technologies for Image-Guided Surgery
Jeff Siewerdsen, PhDDepartment of Biomedical Engineering
Johns Hopkins University
Johns Hopkins UniversitySchools of Medicine and Engineering
Depts. of Biomedical Engineering,Computer Science and Surgery
Overview• “Closing the loop” in image-guided surgery
- Operating rooms of the future
• Imaging modalities for IGS
- MR… US… CT… and cone-beam CT
• From DQE to TRE
- Translation of a new imaging technology from the laboratory to the OR
• Coming advances in IGI
- Evolution and revolution in image-guided procedures
- Meeting new standards in technology assessment
New Opportunities in IGIHigh-precision imaging / guidance / monitoring / adaptation:
- Maximize the performance of existing techniquesIncreased target ablationAvoidance of critical structuresMore efficient therapeutic delivery, workflow
- Expand the application of current techniquesManagement of otherwise “untreatable” diseaseIncreasingly patient-specific therapies
- Develop entirely new therapeutic approachesAdvanced delivery systems (e.g., robotics, PDT, …)Investigate the synergy of adaptive, multi-modality therapies (physical / molecular / cellular / pharmaceutical)
- Expose fundamental factors determining outcome
Current technologies for IGI do not provide a “closed loop.”
Planning and Navigation
The PatientThe Surgeon
Image-Guided Intervention (IGI)
Treatment Delivery
Intra-operative imaging helps to close the loop.
Image-Guided Intervention (IGI)
The Surgeon
Planning and NavigationIntra-Operative Imaging
Treatment Delivery
The Patient
Cycle of IGI
Planning andNavigationResponse
Imaging
Intervention
ORs of the FutureFor example: AMIGO: Advanced Multi-Modality Image-Guided OR
F Jolesz, C Timpani, et al., CIMIT, BWH
UltrasoundFluoroscopyEndoscopyMicroscopy
Patient transport
3T MRI PET-CT
• Emerging themes:- Computerized integration of systems / technologies
(e.g., planning and real-time navigation)- A wealth of data presented intra-operatively- Advanced therapy delivery systems (e.g., robotics)- Multi-modality imaging
• The immediate challenges:- Implementation, integration, and evaluation- Comparative effectiveness
• The longer-term challenges:- Cost- Entirely new technology advances, specific to the OR- Streamlined integration with therapy workflow
ORs of the Future
• Imaging technologies- Continuous advances in Dx imaging technology apply
to Tx imaging as well- However, challenges for Tx imaging go beyond direct
implementation in the arena of therapy
• Imaging for Tx guidance involves distinct:- Imaging tasks- Requirements (image quality, speed, accuracy, etc.)- Constraints (dose, patient access, etc.)
• Overall challenge:- Develop imaging strategies motivated directly by the
objectives and constraints of therapy guidance
Imaging for Therapy Guidance
X-ray Fluoro / CBCT
Imaging Modalities for IGICT Ultrasound
MR Nuclear MedicineOptical
Imaging Modalities for IGIKey Characteristics• Real-time
(or near-real-time)
• Radiation dose~1/10 – 1/2 of Dx CT
• Sub-mm resolution
• Soft-tissue visibility
X-ray Fluoro / CBCT
Cone-Beam CT
Projection dataMultiple projections
over ~180o
Volume reconstructionSub-mm spatial resolution
+ soft tissue visibility
Mobile C-Armfor Intraoperative Cone-Beam CT
Multiple projection images acquired over ~180o
2D Image acquisition- Nominal: 60 s- High-speed motor: 10 s
3D Image reconstruction- Nominal: 60 s- High-speed recon: 10 s
Radiation dose- ~1/10th that of Dx CT
MotorizedOrbit Replace XRII with
Flat-Panel Detector
GeometricCalibration
Tube + CollimatorModification (FOV)
Image Acquisition3D Reconstruction
Control System
Mobile Isocentric C-ArmSiemens PowerMobil
Mobile Isocentric C-ArmCone-Beam CT-Capable C-Arm
Pre-clinical platform for multi-mode Fluoro / CBCT guidance
Image Acquisition3D Reconstruction
Control System
Applications in IG Surgery
Platform for optimizing / integrating imaging and
navigation
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
Applications in IG Surgery
In vivo studiesof image quality and geometric precision
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
Applications in IG Surgery
Soft-tissue visualization and real-time planning
Resection ofsub-palpable lesions
Applications in IG Surgery
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
Applications in IG Surgery
Maximal target ablation and critical structure
avoidance
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
An IntegratedImage Guidance System
for Head and Neck Surgery
CBCT C-Arm Real-Time Tracking Endoscopy
Image-to-World Deformable Reg Endo-to-CBCT
Pre-Op CT, MR, etc. Surgical Planning
3D / 4D Multi-ModalityVisualization
Integration of Image Guidance Systems
Intr
a-O
pR
egP
re-O
p
?
Multi-Scale Demons Algorithm
1
0 5 10 15 20 25 300.93
0.94
0.95
0.96
0.97
0.98
0.99
Imag
e C
ross
-Cor
rela
tion
Iteration #
Bin x8
Bin x4Bin x2
Bin x1
11 sec
12 sec
18 sec52 sec
Def
orm
atio
n F
ield
Diff (I1 – I0Rigid)
Diff (I1 – I0Deformable)
RIG
IDD
EF
OR
MA
BLE
Intra-Op CBCT (POST-Resection)
Intra-Op CBCT (PRE-Incision)
3D Deformable Image Registration
Rig
id R
egD
emons
Reg
3D Deformable Image Registration:“Demons” Algorithm
0
1
2
3
4
5
6
7
8
Targ
et R
egis
trat
ion
Err
or
(mm
)
RigidDemons
Registration Performance (TRE)
Performance Evaluation10 PatientsRigid vs. Demons6 Anatomical Targets
TemporalBone
L RMandibleL R Spine Soft
Tissue
RigidDemons
Real-Time Tracking and Navigation
Stereoscopic IR Camera(NDI Polaris) Fiducials
TargetCentroid
Optimal fiducial arrangementsAutomatic registration of image and tracking systems
Tungsten BB(1.0 mm radius)
InfraredReflective Sphere(5.8 mm radius)
Multi-Modality Marker(IR-Xray)
Automatic Tracking RegistrationTarget Registration Error (TRE)Manual Registration
TRE = (1.29 ± 0.34) mmAutomatic Registration
TRE = (1.14 ± 0.20) mm� Comparable accuracy� Improved reproducibility
Markers fixed to cranium surfaceTRE = (0.83±0.20) mm
Markers off-surface(better arrangement for H&N)
TRE = (1.24±0.20) mm� NSS (p=0.79)
WorkflowManual Registration: minutesAutomatic Registration: seconds, automatic with each CBCT scan
Integrated CBCT + Endoscopy
PolarisVicra
C-Arm
3D Visualization + Video Endoscopy
CadaverHead
Tracked EndoscopePointer
Application in Sinus and Skull Base SurgeryPre-Clinical Studies
• Tomosynthesis- Image quality and dose- Localization accuracy
• Temporal Bone- Image quality (spatial resolution)- Visualization of cochlear implants
• Sinus ablation- Identification of CSF leak- Frontal recess, ethmoid, sphenoid
• Skull base- Completeness of target ablation- Avoidance of critical structures- Quantitative analysis of surgical
performance under CBCT guidance
CBCT-Guided Sinus Surgery
• Identification of CSF LeakCadaver specimenTotal sinus ablation
• Breach introducedDiameter: 1, 2, 4 mm1-2: Cribriform3-4: Lateral lamella5-6: Fovea ethmoidalis7-8: Planum
• Observer study5 surgeons, 1 radiologist5-point detectability scaleMin detectable breach
No CSF Breach
Coronal CBCT
Ethmoid Air Cell Ablationin proximity to
Fovea Ethmoidalis
CBCT-Guided Sinus Surgery1 mm Breach
2 mm Breach 4 mm Breach
5= Perfectly obvious4= Visible3= Visible, but challenging2= Could be overlooked1= Unable to identify
CBCT-Guided Sinus Surgery
0
1
2
3
4
5
0 1 2 3 4 5
Defect S ize (mm)
(d) Planum
Obs
erve
r Sc
ore
Defect S ize (mm)
Y = 0.68x + 2.02
0
1
2
3
4
5
0 1 2 3 4 5
Defect S ize (mm)
(d) Planum
Obs
erve
r Sc
ore
Defect S ize (mm)
Y = 0.68x + 2.02
Scor
e (D
etec
tabi
lity)
Detection of CSF Leak
Rating Scale:
Confident detection >~1.5 - 2 mm breach
Skull Base Surgery:Target Abation in the Clivus
Intra-Operative CBCT
TARGET volumeNORMAL volume
Critical
Skull Base Surgery:Target Abation in the Clivus
Intra-Operative CBCT
TARGET volumeNORMAL volume
Post-Operative CBCT
TARGET RemainingNORMAL Remaining
Critical Critical
Hypothesis-testing framework for evaluation of surgical performance
Fraction of Tumor
Excised
Fraction of Normal
Remaining
= Sensitivity =
= Specificity =
FNTP
TP
+
TNFP
TN
+
Positive Predictive
Value= PPV =
FPTP
TP
+
Negative Predictive
Value= NPV =
FNTN
TN
+
Quantification of Surgical PerformanceQuantification of Surgical Performance
0.0
0.2
0.4
0.6
0.8
1.0
0.0 0.2 0.4 0.6 0.8 1.0
CBCT-Guided
Unguided(conventional)
1-Specificity(Fraction of Normal Excised)
Sen
sitivity
(Fra
ctio
n o
f Targ
et E
xcis
ed)
CBCT-Guided Skull Base Surgery
Normal TissueTarget Volume (excised)Target Volume (residual)
Translation to Clinical Trials
C-Arm Trials: Mandibulectomy
Sca
n 1
Sca
n 2
Sca
n 3
Sca
n 4
Sca
n 1
Target(Radionecrosis)
Sca
n 2
Sca
n 3
Pla
n C
utPlan
Cut
ResectionSca
n 4
FibulaReconstruction
Plates
C-Arm Trials: Invasive Tumor
Sca
n 1
Sca
n 2
Sca
n 3
Sca
n 4
Sca
n 1
ChondrosarcomaSca
n 2
Craniotomy
Sca
n 3
Tumorresection
Tumormargins
Sca
n 4
Closure
Packing
Looking Ahead:Opportunities in IGI
Multi-Modality Intra-Operative Imaging- Essential to ‘closing the loop’ in image-guided surgery
MR / US / CT / Cone-beam CT- More than simple translation from Dx to Tx
New development for the task of surgical guidance
Integration of Guidance Systems- Essential to preserving / improving surgical workflow
Intraoperative imagingImage registrationPlanning and real-time navigation3D visualizationTherapeutic delivery (e.g., robotics)
ORs of the FutureCurrently characterized by conglomeration of technology
- For example: MR/CT/US + Robot- Engineering challenge is beyond simple integration
Rather, a re-engineering effort (or new system altogether) is required according to the surgical task
ORs of the (more distant) future- Hopefully exceed conglomerate “IGORs” of the present
Technologies created specifically for the ORStreamlined integration with surgical workflow
An inter-disciplinary approach to new technologies in the operating theatre
- (Surgeons, Nurses, Anesthesia) + (Physicists, Engineers)- Radiation therapy offers a successful model example
Demonstrating True BenefitSuch IG systems and ORs will need to meet new standards of performance: comparative effectiveness
- Within technology (intra-metrics):Optimal implementation of ‘Technology X’
- Between technologies (inter-metrics):Performance of ‘Technology X’ vs ‘Technology Y’
- Clinical justification:Effectiveness of therapy under ‘Tech X’ vs standard of care
Quantification of surgical performance is key- Short of randomized clinical trials, approaches like
hypothesis-testing could be valuable
- Rigorous computerized planning
- Quantitative evaluation of planned (and delivered) Tx
AcknowledgementsUniversity Health Network
• JC Irish, MD – Surgical Oncology• G Bachar, MD• E Barker, MD• H Chan, PhD• MJ Daly, MSc• M Rafferty, MD• A Vescan, MD
University of Toronto• N Hamming, MHSc• S Nithiananthan
Funding Support• NIH R01-CA112163• NIH R01-CA127444• Siemens Healthcare (SP, Erlangen)• Princess Margaret Hospital Foundation
Thank you.Thank you.Thank you.Thank you.
Cone-Beam CT
Projection dataMultiple projections
over ~180o
Volume reconstructionSub-mm spatial resolution
+ soft tissue visibility
Applications in IG Surgery
Platform for optimizing / integrating imaging and
navigation
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
Applications in IG Surgery
In vivo studiesof image quality and geometric precision
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
Applications in IG Surgery
Soft-tissue visualization and real-time planning
Resection ofsub-palpable lesions
Applications in IG Surgery
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
Applications in IG Surgery
Maximal target ablation and critical structure
avoidance
• Orthopedic Surgery• Spine Surgery• Brachytherapy• Ear Surgery• Interventional Radiology• Urology• Lung Surgery• Breast Surgery• Head and Neck Surgery
Skull Base Surgery:Target Abation in the ClivusIntra-Operative CBCT
TARGET volumeNORMAL volume
Critical
Skull Base Surgery:Target Abation in the ClivusIntra-Operative CBCT
TARGET volumeNORMAL volume
Post-Operative CBCT
TARGET RemainingNORMAL Remaining
Critical Critical
C-Arm Trials: Maxillectomy
Sca
n 1
Sca
n 2
Sca
n 3
Sca
n 4
Sca
n 1
Adenoid CysticCarcinoma
Sca
n 3
Resection
Sca
n 4
DentalProsthesis