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

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

  1. 1. CYBERKNIFE SRS & SBRT P.Mahadev MD DNBApollo Speciality Cancer Hospital Chennai
  2. 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. 3.  Higher confidence in tumor targeting Reliable mechanisms for generating focused, sharply delineated dose distributions with a rapid dose fall off Reliable accurate patient positioning accounting for target motion related to time dependent organ movement IMAGE GUIDANCE AND EFFICIENT TRACKING MECHANISM Longer times than conventional RT, hence patient comfort is an issue
  4. 4. SRSSBRTIMRT FOR PROSTATESRT
  5. 5. 3 4 5 6 2 1
  6. 6. Pitch Yaw Roll
  7. 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. 8. The table consists of 12 fixed cones and housings of Fixed and Iris Collimator Laser SensorCollimator sizes(mm): 5, 7.5, 10, 12.5, 15, 20, 25, 30, 35, 40, 50, 60
  9. 9.  There are two essential features of the CyberKnife system that sets it apart from other stereotactic radiosurgery methods.
  10. 10.  radiation source is mounted on a precisely controlled industrial robot. The image guidance system(continuous tracking system) Eliminates the need of gating techniques and restrictive head frames
  11. 11. The Cyberknife treatment delivery is based on the following tracking systems 6D_ Skull tracking system Fiducials tracking system Synchrony tracking system X_sight Spine tracking system X_sight Lung tracking system
  12. 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. 13.  Fiducial tracking system: used for soft tissues, where gold fiducials can be implanted. Minimum of 3 nos. to be implanted
  14. 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 imagersThree 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. 15. • 790 fiducials• 85% successfully placed• 2 Patients developed pneumothorax• 6 fiducials migrated- 3 in lung, 2 in liver& 1 in prostate
  16. 16. Respiratory-induced motion of tumors causes significant targeting uncertainty  Lung, liver, pancreas, Prostate,kidneyTraditional radiation therapy margins are not optimized for high-dose radiosurgery
  17. 17. Imaging and Tumor Targeting  Traditional IGRT daily set-up imaging maybe inadequate for sub-millimeter accuracyImmobilizationBreath Holding
  18. 18. Imaging and Tumor Targeting  Traditional IGRT daily set-up imaging maybe inadequate for sub-millimeter accuracyImmobilizationBreath HoldingGating
  19. 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. 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. 21. Two features to form the basis for accuracy Fiducials, implanted prior to Optical markers on a special treatment patient vest
  22. 22.  Prior to treatment start: creation of dynamic correlation model Imaging system takes positions of fiducials at Markers are monitored in discrete points of time real time by a camera system
  23. 23.  Prior to treatment start: creation of dynamic correlation model Imaging system takes positions of fiducials at Markers are monitored in real time by a camera discrete points of time system displacement displacement time time
  24. 24.  This process repeats throughout the treatment, updating and correcting beam delivery based upon the patient’s current breathing pattern displacement displacement time time
  25. 25.  X-sight Spine tracking system:used to track spine lesions which are close to spine from C1 to L5&sacrum Uses the bony anatomy of spine to track the tumors in close relation to spine eliminating the need for fiducials X-sight spine is now possible in prone position as well
  26. 26.  The appropriate tracking method has to be chosen during planning itself No treatment is possible without planning and proper tracking method
  27. 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. 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. 29.  The mechanical accuracy of the system is 0.12 mm , according to Accuray The system maintains sub-millimeter tracking accuracy, if the patient positions are within the following 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. 30.  The Robot will correct its position if the off set values are with in the specified limits The robot will trigger an Emergency Stop outside of these tolerances
  31. 31. Gamma knife, X-knife are probably as good.May have an advantage for larger lesions requiring multiple fractions- meningioma, acoustic schwanomma etcMore patient friendly(frame)Continuous image guidance
  32. 32. T1&T2 NSCLC – inoperable or medical contraindication or patient refuses surgery, ideal lesion <3cm & peripheral locationoligometastasis
  33. 33. in a uniform population of medically inoperable patients with peripherally located early lung cancer, the RTOG 0236 study dem- onstrated 98% local control (within the primary tumor) and 87% local- regional control (within the ipsilateral lobe, hilum, and mediastinum) at 3 years with an intensive regimen of 60 Gy in 3 fractions
  34. 34. RADIOBIOLOGICAL RATIONALE: LOW APLHA/BETA RATIOGOOD RESULTS OBTAINED WITH HDR brachytherapyLESS INVASIVE THAN BRACHYTHERAPY
  35. 35. Ju AW et al :Radiat oncol jan201341 pts intermediate riskMedian fu 21 mo99% biochemical PFSNo gr3/4 bladder or bowel morbidityNo significant change in sexual QOL
  36. 36. BRACHYTHERAPY: 10/10.5 Gy x3 over 24 hours, each fraction 8 hours apartBED : 130/142 GySBRT : 7.25 Gy x5 over 5 daysBED: 123 Gy
  37. 37. T1 T2 PSA<10 PSA>10 GS<7 GS>7 TOTALHDR 30 22 35 17 40 12 52CK 34 32 40 16 35 31 66IMRT/I 94 186 94 186 126 154 280GRT
  38. 38. MEDIAN FU 2 YR MEDIAN BIOCHEMI PSA CAL NADIR PFSHDR 22 MONTHS 94% 0.8CK 16 MONTHS 96% 1.0IMRT/IGRT 48 MONTHS 89% 0.9
  39. 39. Fiducials placed at surgeryOne planning CT with oral and IV contrast1000cGy to +ve margins 3-4 weeks post OP5040cGy 5-6 field IMRT6-8 weeks postOPConcurrent XelodaAdjuvant Gemcitabine
  40. 40.  Intramedullary spinal cord AVM’s only Not amenable to microsurgical excision/embolisatio symptomatic
  41. 41.  Neurologic examination MRI Conventional 2D spinal angio
  42. 42. Spine tracking1.25 mm contrast enhanced axial CTTarget volume traced on CT in cojunction with:MRI 2D/3D spinal angio
  43. 43.  24 patients 15 males 9 females Time from diagnosis to SRS:7.8 yrs Mean age at SRS 34 Yrs Presentation :12 hemorrhages 12 had progressive pain or myelopathy secondary to steal or venous congestion
  44. 44.  13 cervical 8 thoracic 3 conus medullaris
  45. 45.  Target volume :2.8cc(0.26-15 cc) Marginal nidus dose :2050cGy(1600-2100) Prescription isodose line:79%(68-90%) Dmax:2580cGy Fractions:1 to 4
  46. 46. Angiographic outcome:significant AVM reduction in all patients >1yr post SRS6 of 19 patients obliterateNo angio done in 5 patientsClinical outcome:no further hemorrhages
  47. 47. 3 PATIENTS28 YRS OLD LADY EMBOLISATION DONE TWICE PRESENTED WITH SEVERE PAIN IN THE POPLITEAL FOSSA AND CALF REGION56 YEARS OLD LADY WITH SUDDEN ONSET OF MYELOPATHYBOTH THE PATIENTS RESPONDED WELL25 yr old young man, repeated embolisations done,had no improvement
  48. 48. Current prescription dose to nidus is 2000 cGy in 2 sessions to larger lesions & 16-18 Gy for small (<0.7 cc) AVMradiosurgery is a reasonable option in most type II spinal cord AVMs
  49. 49. Gerszten et al., Radiosurgery for spinal metastases: clinical experience in 500 cases from a single institution Volume 32, Number 2, pp 193–199, 2007 500 cases of spinal metastases treated by CyberKnife ® Radiosurgery at the University of Pittsburgh 73 cervical, 212 thoracic, 112 lumbar, and 103 sacral lesions Long-term pain improvement occurred in 290 of 336 cases (86%) Long-term tumor control in 90% of lesions treated with radiosurgery as aprimary treatment modality Long-term tumor control in 88% of lesions that failed other therapies
  50. 50. Stereotactic radiosurgery is not a substitute to surgery but an alternative when indicatedSBRT is becoming a component in the multidisciplinary treatment of CancerIn selected cases, SBRT may prove to be a curative modality of treatment in early cancers

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