Igrt Srt For Lung Cancer

6,156 views

Published on

Published in: Health & Medicine
0 Comments
4 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
6,156
On SlideShare
0
From Embeds
0
Number of Embeds
23
Actions
Shares
0
Downloads
634
Comments
0
Likes
4
Embeds 0
No embeds

No notes for slide

Igrt Srt For Lung Cancer

  1. 1. Image-Guided and Stereotactic Radiotherapy (IGRT/SRT) for Lung Cancer Gregory S. Sibley, M.D. November 17, 2008
  2. 2. Outline Evolution of Technology Intensity-Modulated Radiotherapy (IMRT) Image-Guided Radiotherapy (IGRT) Stereotactic Radiotherapy (SRT) Tomotherapy Specific Case
  3. 3. Outline Evolution of Technology Intensity-Modulated Radiotherapy (IMRT) Image-Guided Radiotherapy (IGRT) Stereotactic Radiotherapy (SRT) Specific Disease Sites Tomotherapy
  4. 4. Evolution of Technology 1970’s: Cobalt-60, treatment guided by surgical anatomy and plain radiographs. Doses calculated from depth-dose charts. 1980’s: Cross-sectional imaging (CT) available to guide treatment delivery. 1990-1995: “Home-grown” 3D conformal radiotherapy planning systems appearing allowing Beam’s Eye View
  5. 5. Evolution of Technology 1995-2000: Commercial 3D CRT planning systems available with routine adoption by most centers. 1998: Sibley acquires 3D planning system. 1999-2003: Patients routinely planned and treated with 3D CRT and 3D dose calculation. 2002: Sibley Cancer Center opens 11/02 with state-of-the-art digitally controlled linear accelerators.
  6. 6. External-Beam Radiotherapy Photon energy 6-23 MV Fields collimated by internal jaws Fields shaped by internal leaves (MLC’s) Digital information transfer
  7. 7. Evolution of Technology 2003: 5/03 first patient treated with Intensity- Modulated Radiotherapy (IMRT) 2004: CT scanner/simulator installed in Cancer Center 2006: Gold fiducial markers implanted routinely for prostate cancer for Image-Guided Radiotherapy (IGRT) 2008: Tomotherapy with Stereotactic Radiotherapy capability (SRT)
  8. 8. Outline Evolution of Technology Intensity-Modulated Radiotherapy (IMRT) Image-Guided Radiotherapy (IGRT) Stereotactic Radiotherapy (SRT) Specific Disease Sites Tomotherapy
  9. 9. Intensity-Modulated RT (IMRT) Requires exacting definition of target structures and use of definitions: GTV, CTV, PTV GTV: Gross tumor volume CTV: Clinical target volume = region at risk for subclinical spread PTV: Planning target volume = margin added for setup uncertainty
  10. 10. IMRT: Intensity-Modulated RT Treatment typically delivered through five or seven beams with multiple segments treated to various intensities (i.e. intensity modulated) End result is a dose distribution that closely matches request Requires expert physicians, expert physicists, expensive technology and significant amounts of time
  11. 11. IMRT
  12. 12. Radiation Oncology IMRT Treatments 6000 5500 5000 4000 3104 3000 2184 2000 1000 837 00 0 0 0 1999 2000 2001 2002 2003 2004 2005 2006 Year
  13. 13. IMRT vs 3D: 3D plan
  14. 14. IMRT vs 3D: IMRT plan
  15. 15. IMRT vs 3D: DVH’s GTV Esophagus Lung
  16. 16. IMRT Appropriate Patient?
  17. 17. IMRT Appropriate Patient?
  18. 18. IMRT clearly helps Tumor IMRT: dashed line 3DCRT: solid line Esophagus
  19. 19. Outline Evolution of Technology Intensity-Modulated Radiotherapy (IMRT) Image-Guided Radiotherapy (IGRT) Stereotactic Radiotherapy (SRT) Specific Disease Sites Tomotherapy
  20. 20. IGRT: Image-Guided RT Daily targeting of internal structures instead of skin marks or bony landmarks. Performed since 2006 by us for all prostate cancers by using gold “fiducial” seeds. Trilogy and Tomotherapy are technologies that provide daily “CT-like images” that are matched to planning CT images for positioning. New standard for state-of-the-art radiotherapy
  21. 21. IGRT - Lung
  22. 22. Outline Evolution of Technology Intensity-Modulated Radiotherapy (IMRT) Image-Guided Radiotherapy (IGRT) Stereotactic Radiotherapy (SRT) Specific Disease Sites Tomotherapy
  23. 23. Stereotactic Radiotherapy (SRT) Initially used only for cancers and disorders in the brain. Stereotactic Body Radiotherapy (SBRT) uses similar concepts to treat cancers outside of the brain. SRT is not radiotherapy. One to five very large doses are used to “kill” everything within the defined target, i.e. radiosurgery.
  24. 24. SRT Machines Trilogy is a modified linac that delivers SRT through setup and monitoring with a kV imager. CyberKnife is a dedicated SRT machine that is not designed to provide radiotherapy capability. Small, precise beams and long treatment delivery times. Tomotherapy is a linac that images and delivers treatment through a rotational gantry (like CT). Provides image guidance with every treatment and can simultaneously treat multiple targets quickly.
  25. 25. Trilogy (Varian)
  26. 26. CyberKnife
  27. 27. Tomotherapy
  28. 28. Outline Evolution of Technology Intensity-Modulated Radiotherapy (IMRT) Image-Guided Radiotherapy (IGRT) Stereotactic Radiosurgery (SRS) Tomotherapy Specific Disease Sites
  29. 29. HI-ART Tomotherapy Unit Gun Board Linac Control Computer Circulator Magnetron Pulse Forming Network and Modulator Data Acquisition System High Voltage Power Supply Beam Stop Detector
  30. 30. TomoTherapy Advantages •No Gantry-Patient Collision •No Wedges •No Gantry Angles •No Collimator Angles •No Table Angles •No Hand Pendants •No MLC Shapes or Coordinates •No MLC Motors •No Field/Jaw size •No Field Light •No Electrons •No Electron Cones
  31. 31. Image-guided Therapy: Principles Image guidance ensures that relative positions of isocenter and target are the same during treatment and in treatment plan This potentially allows: Reduced treatment margins Increased dose Reduced complications Avoid misses
  32. 32. CT VRCT 2cGy Image 1 CT and VRCT Image sets Image 2 using same window and level adjustments Image 3 Image 4 Courtesy of University of Wisconsin
  33. 33. Esophagus IGRT After 2400cGy (12 Fx) Original Planning CT CT of the day (TomoImage) Courtesy: Dr. Dan Petereit M.D., Rapid City Regional Hospital T-MKT-AP0068
  34. 34. Stereotactic Radiotherapy (SRT) for Stage I Non-small Cell Lung Cancer
  35. 35. SBRT for Stage I Lung Institution # Patients Local Control Yamanishi, Japan 257 86%* (92%) Japan 131 96% Aarhus (Denmark) 89 89% Wash U 70 83% Indiana U (protocol) 70 88% Cleveland Clinic 94 97% Amsterdam 206 97%
  36. 36. Stereotactic- The Patient
  37. 37. SRT- The Simulation 4D-CT simulation is performed (3D plus motion). 36 multislice CT synchronized with chest tension belt provides images at each phase of respiration. Abdominal pressure plate added (when needed) to limit respiratory motion Gating utilized (when needed) for excessive motion
  38. 38. SRT- The Immobilization
  39. 39. Stereotactic Radiosurgery (SRS) Requires exacting immobilization and targeting Fiducial markers not required with TomoTherapy
  40. 40. Stereotactic- The Tomo Plan
  41. 41. Stereotactic- The Setup
  42. 42. Stereotactic- Ready to Treat
  43. 43. SRT- The Treatment Many fractionation schedules have been used, but the “winning” regimens… 20 Gy x 3 = 60 Gy 12 Gy x 4 = 48 Gy (near sensitive structures)
  44. 44. SRT- Complications Emerging treatment with paucity of long-term data, but… Peripheral lesions: develop rib fractures in 13/31, 9/42, 3/131, 9/86 Apical lesions: (37/273 pts at IU, 89% LC) 7/37 developed gr 2-4 brachial plexopathy (1 hand paralysis) Misc: bronchovascular fistula, pneumonitis Multi-inst study: 11/70 Gr 3-5 toxicity
  45. 45. Patients courtesy of University of Alabama Potential New Clinical Opportunities: Re-treatment for patients not eligible for radiation therapy before TomoTherapy due to cord tolerance
  46. 46. SRS-Applications Highly effective and time efficient Most common sites: brain, spine, lung, liver Useful for recurrent tumors in previously irradiated fields Tumor control is seen in 80-90% of metastases treated, but survival is not impacted Curative for Stage I lung cancers…new standard of care for medically inoperable patients
  47. 47. Summary Image-Guided Radiotherapy is new gold standard for radiotherapy Tomotherapy is elegant solution for IGRT and works well “out of the box” Stereotactic Radiosurgery is effective and time efficient method of palliation TomoTherapy delivers SRS as well, without need for fiducial markers
  48. 48. The End

×