apollo hydbd feb8 2013 (cancer ci 2013) p. mahadev md

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  • 1. CYBERKNIFESRS & SBRTP.Mahadev MD DNBApollo Speciality Cancer HospitalChennai

2. MANAGEMENT AND DELIVERY OF IMAGE GUIDED HIGH DOSE RADIATION THERAPY WITH TUMOR ABLATIVE INTENT WITHIN A COURSE OF TREATMENT THAT DOES NOT EXCEED 5 DAYS 3. Higher confidence in tumor targeting Reliable mechanisms for generating focused, sharplydelineated dose distributions with a rapid dose fall off Reliable accurate patient positioning accounting for targetmotion related to time dependent organ movement IMAGE GUIDANCE AND EFFICIENT TRACKINGMECHANISM Longer times than conventional RT, hence patient comfortis an issue 4. SRSSBRTIMRT FOR PROSTATESRT 5. 345 621 6. PitchYaw Roll 7. Robot is capable of delivering radiation fromdifferent 100 nodes, with each node is capable ofgiving a maximum 12 different beams.Usage of these nodes depends on the treatment roomconstraints 8. The table consists of 12 fixed cones and housings of Fixed and Iris CollimatorLaser SensorCollimator sizes(mm): 5, 7.5, 10, 12.5, 15, 20, 25, 30, 35, 40, 50, 60 9. There are two essential features of theCyberKnife system that sets it apart from otherstereotactic radiosurgery methods. 10. radiation source is mounted on a preciselycontrolled industrial robot.The image guidance system(continuous trackingsystem) Eliminates the need of gating techniques andrestrictive head frames 11. The Cyberknife treatment delivery is based on thefollowing tracking systems 6D_ Skull tracking system Fiducials tracking system Synchrony tracking system X_sight Spine tracking system X_sight Lung tracking system 12. 6D_ Skull tracking system: used for intra-cranial lesions up to C2 Bony anatomy of the skull is used as reference for tracking 13. Fiducial tracking system: used for soft tissues, where gold fiducials can be implanted. Minimum of 3 nos. to be implanted 14. close proximity to the lesion to be treated well-separated (by about 1 cm) non-overlapping on projections from the in-room x- ray imagersThree markers are sufficient for unique spatial localization, but in practice 4-5 are often placed in case of loss or suboptimal placement of markers 15. 790 fiducials 85% successfully placed 2 Patients developed pneumothorax 6 fiducials migrated- 3 in lung, 2 inliver& 1 in prostate 16. Respiratory-induced motion of tumors causes significant targeting uncertainty Lung, liver, pancreas,Prostate,kidneyTraditional radiation therapy margins are not optimized for high-dose radiosurgery 17. Imaging and Tumor Targeting Traditional IGRT daily set-up imaging maybe inadequate for sub-millimeter accuracyImmobilizationBreath Holding 18. Imaging and Tumor Targeting Traditional IGRT daily set-up imaging maybe inadequate for sub-millimeter accuracyImmobilizationBreath HoldingGating 19. option for dynamic tracking without the use of implanted fiducials.Tumor localization is accomplished using auto- mated real-time image segmentation of the in-room x-ray images based on the contrast of the tumor itself. 20. best used for lesions with sufficient contrast in density from the surrounding anatomy to be clearly visualized on both of the in-room x-ray imagers, i.e., those located in the lung periphery at least 1.5 cm in size, and that do not overlap other dense anatomical structures, such as the spine, diaphragm, and heart in the projection views 21. Two features to form the basis for accuracy Fiducials, implanted prior to Optical markers on a special treatment patient vest 22. Prior to treatment start: creation of dynamic correlation modelImaging system takes positions of fiducials atMarkers are monitored in discrete points of timereal time by a camera system 23. Prior to treatment start: creation of dynamic correlation model Imaging system takes positions of fiducials atMarkers are monitored in real time by a cameradiscrete points of time systemdisplacementdisplacement time time 24. This process repeats throughout the treatment, updating and correcting beam delivery based upon the patients current breathing pattern displacement displacement time time 25. X-sight Spine tracking system:used to track spinelesions which are close to spine from C1 to L5&sacrum Uses the bony anatomy of spine to track the tumorsin close relation to spine eliminating the need forfiducials X-sight spine is now possible in prone position as well 26. The appropriate tracking method has to be chosen during planning itself No treatment is possible without planning and proper tracking method 27. Treatment planning is done on the CT images of slice thickness 1mm acquired at 125 kV and 400 mAs with a pixel size of 512 x 512 MRI, PET and 3D-Angio images can be used to fuse with the primary CT images for target and OAR delineation 28. Planning System (MultiPlan) uses inverseplanning algorithm with following options1. Conformal Planning2. Sequential optimizationThe system provides the user the option ofusing either ray tracing method or Monte Carlo 29. The mechanical accuracy of the system is 0.12mm , according to Accuray The system maintains sub-millimeter trackingaccuracy, if the patient positions are within thefollowing limits Left / Right (Lat) 10 mm Ant/ Post (Ver)10 mm Sup/ Inf ( Long) 10 mm Roll (Left / Right) 10 Pitch (Head Up / Down) 10 Yaw ( C.W / C.C.W) 30 30. The Robot will correct its position if the off set valuesare with in the specified limits The robot will trigger an Emergency Stop outside ofthese tolerances 31. Gamma knife, X-knife are probably as good.May have an advantage for larger lesions requiring multiple fractions- meningioma, acoustic schwanomma etcMore patient friendly(frame)Continuous image guidance 32. T1&T2 NSCLC inoperable or medical contraindication or patient refuses surgery, ideal lesion 1yr post SRS6 of 19 patients obliterateNo angio done in 5 patientsClinical outcome:no further hemorrhages 47. 3 PATIENTS28 YRS OLD LADY EMBOLISATION DONE TWICE PRESENTED WITH SEVERE PAIN IN THE POPLITEAL FOSSA AND CALF REGION56 YEARS OLD LADY WITH SUDDEN ONSET OF MYELOPATHYBOTH THE PATIENTS RESPONDED WELL25 yr old young man, repeated embolisations done,had no improvement 48. Current prescription dose to nidus is 2000 cGy in 2 sessions to larger lesions & 16-18 Gy for small (