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Prostate IGRT With Setup Intelligence 4sharing

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Prostate IGRT With Setup Intelligence  4sharing Prostate IGRT With Setup Intelligence 4sharing Presentation Transcript

  • Implementing an IGRT correction strategy using IMPAC Setup Assist/Intelligence IMPAC Mid-Atlantic Regional Users Meeting May 30, 2008 Carnell J Hampton, Ph.D. Clinical Physics Section Department of Radiation Oncology
  • Learning Objectives After completing this activity, the learner will be able to: Describe the elements of an IGRT on-line correction strategy and discuss how members of the radiation oncology team play a role in the successful implementation of such a strategy Understand and use tools available within MOSAIQ to establish an IGRT correction strategy Discuss challenges and potential pitfalls of the WFUBMC experience implementing a clinical implanted-marker prostate IGRT correction strategy including quality assurance, chart documentation and associated IGRT billing issues W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Conformal Radiotherapy Planning Goal: Optimize the therapeutic ratio by shaping delivery of high-dose radiation to the target volume while sparing surrounding normal structures W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Geometric Uncertainty/Errors Knowledge of geometric uncertainties and their effect on accurate RT are well documented Patient specific geometric uncertainty has implications for insufficient coverage of target or overdosage of normal tissues Uncertainty can be classified into groups defined by the relative relationship between the uncertainty and the patient and treatment coordinate systems Setup error Separation/table sag Voluntary movement during Tx Respiration Rectum/bladder filling Peristalsis Cardiac motion Swallowing W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Relative Uncertainty in RT Advanced imaging, especially temporal imaging, has aided the quantification of uncertainty for specific disease sites. Both simulations and clinical patient studies have begun to document the extent to which geometric uncertainty impacts therapy. Site Delineation Setup Organ Motion Prostate 3-4 mm 3-4 mm 3-4 mm Lung Up to 50 mm 4-6 mm 0-40 mm Breast 6-42 mm 4-6 mm 6 mm Langen 2006 W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Geometric Uncertainties ICRU 62 Terminology CTV=>PTV Includes: PTV IM – Internal IM Margin variation in CTV shape and position of CTV within patient SM – Setup Margin SM GTV uncertainty in patient position and beam alignment No explicit margin for target delineation, which is a function of inter-observer variability and imaging modality W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • What is IGRT? “Real-time” imaging consisting of: 1. 3D volumetrics of soft tissues 2. Efficient acquisition and comparison of the 3D volumetrics, and 3. An efficacious process for clinically meaningful intervention Ling et al, Radiotherapy and Oncology (2006) W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IGRT is useful when: conformality is critical, dose escalation has been shown to provide a benefit, uncertainty due to tumor motion is a concern, changes in tumor or normal structures during the course of therapy require adaptation of the original treatment plan. “IGRT is a quality assurance tool for highly conformal treatment” W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IGRT Process: On-line Correction Initial Setup Imaging Analysis Action Imaging Treatment Imaging Modified from Yin et al, Med. Phys. Pub. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Stereoscopic IGRT for On-line Localization/Correction Derived 3D localization through stereoscopic imaging Automated or semi-automated methods for comparing reference/treatment-time images Image registration or matching based on soft tissue, bony anatomy, implanted markers (IM) and clips, user-generated contours W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Gold markers are 1. placed prior to CT treatment simulation A computer program is used to 4. calculate where the target is on x-ray images and guides the setup of the patient back to the parameters of the treatment plan. Immobilization is created for each patient. A CT 2. scan is acquired for treatment planning and measurements recorded for later setup. A treatment plan is created based on the simulation Once the patient is in 3. CT scan. The 5. the correct position, tumor is radiation is delivered. precisely targeted for radiation therapy. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IGRT Workflow: Therapists’/Dosimetrists’ Role Pre-Therapy Identification of matching target (i.e. IM, contour) used for on-line correction on planning CT or MR Daily Therapy Performing patient setup, image registration, and daily on-line correction Quality assurance monitoring of image registration W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IGRT Workflow: Physicians’ role Patient selection for IGRT Implantation of fiducial markers Review of image registration results, daily imaging Approval of daily images, recommendations to improve patient localization Trend analysis of patients translations over the course of therapy W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IGRT Workflow: Physicists’ Role Acceptance testing and commissioning of image registration software Determination of residual error Investigating patterns of failure Creating guidance documentation Collaborating with M.D. to determine shift action levels Trend analysis of IGRT data Clinical workflow analysis Periodic QA W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Why Prostate IGRT? Known and unknown knowns effect prostate RT IGRT helps address some known knowns Elimination of systematic errors in dose delivery to the prostate will probably have a positive impact on improving the outcome of therapy (Crevosier, IJROBP, 2005). Conformal dose delivery to the target makes dose escalation feasible Wu et al, IJROBP, 2006 W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Prostate IGRT Comparison: Setup Accuracy Figure 1 Comparison of residual errors for different image-guided correction techniques in prostate, in the left-right (LR), anteriorposteri or, and superior- inferior ~2 mm directions. GS Mageras et al, Seminars in Rad. Onc., 2007 W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Implanted Marker IGRT (IM-IGRT): Required Resources Implantable Markers… …& personnel skilled at implantation Localization Software MV/kV Source & Digital Image Receptor W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IM-IGRT: Optional Resources Remote review tools MD Workroom Treatment Console /Office Trending/Data analysis tools W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IM-IGRT Direct or indirect imaging of the prostate alone with human detection of setup errors is insufficient to achieve high precision Fiducial markers implanted via transrectal ultrasound create a permanent implanted coordinate system. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IM-IGRT 3 mm 0.8 mm 3-5 markers typically implanted within prostate Apex, mid-gland lateral, base Markers can be localized with treatment beam (MV) using orthogonal portal images or kV X-ray source/detector W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Implanted Marker (IM) IGRT 3D localization provided by the imaging of markers on orthogonal portal images and the reconstruction of their position within the treatment coordinate system Least-squares minimization technique used to reconstruct marker position in 3D The reference frame defined by CT in treatment planning can be transformed in 3D to the treatment coordinate system and registered with the location of the markers determined from the orthogonal portal images The registration gives the translations needed to align the isocenter determined from the orthogonal images to the isocenter defined in treatment planning W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Limitations of IM-IGRT (Known Unknowns) IM-IGRT uses fiducials as surrogates for tumor position IM-IGRT methods generally account for uncertainties resulting from interfraction rigid organ motion and setup error Margins needed to account for unaccounted for uncertainties such as: Deformation and rotation of the prostate caused by intrafraction organ motion (eg. Rectal and bladder filling, migration of intestinal gas) Uncertainty in target/normal structure delineation W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Sources of Uncertainty (Known Knowns) Patient Localization (1-2mm) Inaccuracies in the imaging and patient- support systems Marker Localization (1.5mm) 1 Finite marker size Calculated fit of rigid body transformation Image quality limitations PTV Marker Migration (1-2mm) 1,2 IM CTV 1Pouliot,IJROBP 2003 SM 2Poggi, IJROBP 2003 GTV W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Establishing Action Levels Using purely geometric evaluations, action levels can be established considering the local planning margins and estimates of the known uncertainties. An action level can be considered reflecting the tradeoff between effort to correct a patient’s position and the desired precision level for treatment. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Establishing Action Levels Planning margins* + uncertainty Ex: If the shift is <= 3mm, no couch move necessary If the shift is >3mm but <=8mm, move couch as directed. No verification image needed. If the shift is > 8mm but <=15 mm, move couch as directed. Acquire verification films. Repeat localization as above. If the shift is >15mm. Notify physics/physician. * CTV-to-PTV = prostate + 7mm/5mm posterior; IMRT treatment planning W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IM-IGRT using MOSAIQ Setup Intelligence Modules for image registration and fusion Point registration Curve registration Manual registration Method for implementing couch offsets for on-line correction Online and offline quantitative analysis tools Support for third-party positioning software W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Image Registration Definitions and “Rules” 2D image registration – registration of a portal/verification image and reference image (DRR) pair resulting in the calculation of a 2D isocenter shift Available only at cardinal angles (0, 90, 180, 270) No verification images with couch rotations The common dimension can be derived (i.e. the sup/inf dimension for independent AP and Lat image reconstruction) W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • R. Lat W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • AP W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Image Registration Definitions and “Rules” Stereoscopic image registration – registration of 2 sets of portal/verification image and reference image (DRR) pairs resulting in the calculation of a 3D isocenter shift the image must be a portal image associated with the same site the angle between incident beams must be greater than 30 and less than 150 degrees to that of the review image the study date and time must be within 10 minutes of the review image the image must be taken on the same treatment machine as the review image the image must have square pixels the image cannot be approved, rejected, or voided. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Preparing for IM-IGRT Treatment Departmental setup Patient or Isocenter Orientation Site Setup How to get there: from the Diagnoses and Interventions window, click Site Setup or from the Treatment Field Definition dialog box Options menu, click Site Setup. Patient orientation must be set W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Registration Editor Set isocenter, scale Identify markers, curves, landmarks for future registration Landmarks locked after recording a registration W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Point Registration Image registration can be initiated from the treatment delivery table window. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Point Registration Select the daily Images W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Point Registration Initiate image registration by clicking the Register button. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • The other image of the stereoscopic pair is selected and the image registration window opens. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • #1 #2 #3 For each verification image, markers are identified corresponding to the reference images W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Graphically review the accuracy of the automatic image registration. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • The calculated offsets are displayed in the image review window. Image registration is complete! W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Localization Trend Review W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Offset References Session (Localization) Offsets Setup error data collected during the treatment session Third Party Offsets Setup error data calculated using other software can be manually added to a patient’s treatment record Prescribed Offsets The systematic setup error can be determined from session offsets W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • On-line Correction Offset Couch Calculator Calculates new couch targets relative to the current couch location W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Shifting the Patient Setup Intelligence calculates and displays the new couch coordinates based on the image registration offsets. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Initial Setup Imaging Analysis Action Imaging Treatment Imaging Modified from Yin et al, Med. Phys. Pub. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IM-IGRT: WFU Experience WFUBMC IM-IGRT program initiated in 2006 50 patients treated with IM-IGRT (2006- present) Hardware/Software Configuration 4 Varian EX Linacs with EPIDs ADAC Pinnacle TPS PortalVision ACCULOC markers/ISOLOC localization software (2 licenses) Multi-Access/MOSAIQ upgrade to Setup Assist/Intelligence in April 2008. W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Setup Intelligence: Advantages over Acculoc Accessibility of image registration to multiple linacs without the need for multiple software licenses Fewer steps needed to perform registration and on-line correction No manual export of portal images No manual entry of current table coordinates No need to print shift information to take into the treatment room Consolidation of daily shift information within the EMR for better documentation W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Setup Intelligence: Advantages over Acculoc Visualization of the reference image alongside the portal image aids in the identification of fiducial markers The capacity to perform and review image registrations remotely The ability to use fewer than 3 markers for image registration Useful when a “bad” marker placement of migrated marker makes the use of 3 markers impossible W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Stereoscopic Localization Challenges Marker Migration ~10% patients impacted by marker migration since 2006 Isocenter ??? Measures of #1 #2 registration error #1 #2 #3 (FRE, mean error) should be monitored #3 frequently W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Stereoscopic Localization Challenges Obeying the “rules” The verification images must have been acquired within 10 minutes of each other. 10 minute time interval for image registration starting from acquisition of 1st image Beware of incorrect time-stamped images! W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Stereoscopic Localization Challenges Marker Imaging Imaging with the graticule in place can obscure implanted markers MOSAIQ can perform portal image scaling manually or automatically using field edge matching W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Quality Assurance Acceptance of image registration software: End-to-end test of CT image acquisition TPS handling Portal image acquisition, Import/export handling, Marker localization and shift calculation, Couch translation W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IGRT Implementation and QA Advanced technologies require new paradigms, training, QA procedures Therapist procedures Patient shift action levels Physician approval protocol/documentation Physics QA procedure Longer patient treatment slots (?) W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Patient Shift Action Levels If the shift is <= 3mm, no couch move necessary If the shift is >3mm but <=8mm, move couch as directed. No verification image needed. If the shift is > 8mm but <=15 mm, move couch as directed. Acquire verification films. Repeat localization as above. If the shift is >15mm. Notify physics/physician. * CTV-to-PTV = prostate + 7mm/5mm posterior; IMRT treatment planning W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IM-IGRT Imaging Dose: Modality Comparison Ex. Pelvic RT Med. Phys. 33, (6), June 2006 Dose estimated for 30 fraction w/at least once daily imaging MV portal imaging kV portal imaging kV CBCT (full (orthogonal ports, (orthogonal ports, 120 rotation, 120 kVp, 4MU per) kVp, 2 mAs/field) 660mAs) 2.1 Gy 0.75 cGy 0.7 Gy* * Twice a day imaging would result in accumulated dose > 1Gy W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • IGRT Billing Stereoscopic X-ray Guidance: CPT 77421 Images fused and registered Customized software used to calculate shifts Shifts made Professional and technical component MD work has to be documented Documentation and Billing of IGRT David Beyer – ASTRO IGRT Symposium 2008 http://www.astro.org/meetings/UpcomingMeetin gs/IGRTSymposium/ScientificProgram/document s/BeyerD.pdf W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Documentation of On-line Correction Localization Trend Review W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Documentation of On-line Correction Image Review/Approval “OK to treat after shift as calculated by localization software.” Daily Patient Offsets W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Documentation of On-line Correction E-chart Notes “OK to treat after shift as calculated by localization software.” W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Documenting Third-Party Offsets ACCULOC Localization Third-Party Offset W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Summary IM-IGRT helps reduce interfraction and setup errors to ~2 mm, providing the quality assurance needed for IMRT and dose escalation An IM-IGRT protocol in combination with appropriate margins provides improved dosimetric accuracy in prostate RT over uncorrected protocols Setup Assist/Intelligence provides a practical and accurate means of performing on-line setup correction W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • SupportPlus Resources Documentation/Videos Image Registration I Image Registration II Setup Intelligence Top 10 Radoc Support Questions W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton
  • Special Thanks Robin McCaw – Elekta/IMPAC NCBH Therapists & Dosimetrists Phillip Smith W A K E F O R E S T U N I V E R S I T Y S C H O O L O F M E D I C I N E CJ Hampton