Imrt A New Treatment Method For Nasopharyngeal Cancer

5,745 views

Published on

Published in: Health & Medicine

Imrt A New Treatment Method For Nasopharyngeal Cancer

  1. 1. IMRT - A New Treatment Method for Nasopharyngeal Cancer <ul><li>Wen-Shan Liu 1 , Hsiang-Chi Kuo 1 , Bin S. Teh 2 , E. Brian Butler 2 </li></ul><ul><li>1 Chung Shan Medical & Dental College Hospital </li></ul><ul><li>2 Department of Radiation Oncology, Baylor College of Medicine </li></ul>
  2. 2. INTRODUCTION
  3. 3. Is conventional radiotherapy good enough for NPC? <ul><li>Local control </li></ul><ul><li>T1 - T2: 80 - 90 % </li></ul><ul><li>T3 - T4: 20 - 60 % </li></ul>
  4. 4. <ul><li>Grade III - IV Complications </li></ul><ul><li>Temporal lobe necrosis: 2 - 33.3 % </li></ul><ul><li>Hearing impairment: 3 - 30.9 % </li></ul><ul><li>Cranial neuropathy: 0 - 4.2 % </li></ul>
  5. 5. <ul><li>Normal tissue complications </li></ul><ul><li>Otitis media: 5 - 41.8 % </li></ul><ul><li>Trismus: 3 - 12 % </li></ul><ul><li>Xerostomia: 35 - 100 % </li></ul><ul><li>Neck fibrosis: 3 - 36.4 % </li></ul><ul><li>Osteonecrosis: 0 - 2 % </li></ul>
  6. 6. Three Major Issues of the NPC <ul><li>How to improve the local control especially for T3 and T4 patients </li></ul><ul><li>How to reduce the post-irradiation late sequelae </li></ul><ul><li>How to reduce the ratio of distant metastasis </li></ul>
  7. 7. The potential benefit of IMRT for NPC <ul><li>Improve the local control especially for concave shape tumors </li></ul><ul><li>Reduce the post-irradiation complications </li></ul><ul><li>Reduce the rate of distant metastasis by improving the local control </li></ul>
  8. 8. Contents <ul><li>To present the preliminary results of IMRT for nasopharyngeal cancer </li></ul><ul><li>To present the CT-based target defining for nasopharyngeal cancer </li></ul><ul><li>To demonstrate the fractionation strategies for intensity-modulated radiation therapy of nasopharyngeal cancer </li></ul>
  9. 9. Patients and Methods <ul><li>Sept to Dec 2000: 13 patients </li></ul><ul><li>Staging: T1-2, N0-2, M0 (AJCC 1997) </li></ul><ul><li>Age: from 24 to 72 years old </li></ul><ul><li>Male : female = 10 : 3 </li></ul>
  10. 11. The procedures of IMRT for nasopharyngeal cancer <ul><li>Immobilization </li></ul><ul><li>Imaging acquisition and contouring </li></ul><ul><li>Dose calculation with inverse planning </li></ul><ul><li>Quality assurance </li></ul><ul><li>Verification the position </li></ul><ul><li>Portal imaging with EPID </li></ul><ul><li>IMRT </li></ul>
  11. 12. Immobilization
  12. 13. Imaging acquisition and contouring
  13. 16. Dose calculation with inverse planning <ul><li>Varians Helios  planning system </li></ul>
  14. 17. Dose limits of inverse planning
  15. 18. Inverse planning
  16. 19. IMRT QA and Treatment MLC Controller TPS Leaf Motion Treatment Machine Record and Verify Log File Indep. MU Calc. DMLC Port Film/ DRR Comparison Film/Ion Chamber Verification ?
  17. 20. NPC2: 測量值 NPC2: 運算值
  18. 21. NPC4: 測量值 NPC4: 運算值
  19. 22. Verification the treatment position by simulation
  20. 23. Verification the treatment position by portal imaging (EPID)
  21. 24. Intensity-modulated radiotherapy (IMRT)
  22. 25. RESULTS
  23. 28. Acute Reaction
  24. 29. Dosimetry
  25. 31. <ul><li>Response evaluation by CT scan </li></ul>
  26. 32. <ul><li>Response evaluation by CT scan </li></ul>
  27. 33. Discussion <ul><li>How to define the treatment targets? </li></ul><ul><li>How to decide the doses to the different targets and different critical organs? </li></ul><ul><li>Is the IMRT really better than conventional radiotherapy? </li></ul>
  28. 34. How to define the treatment targets?
  29. 35. How to define the treatment targets? <ul><li>Medial : c-spine body and pharyngeal wall </li></ul><ul><li>Lateral : excluding parotid, sternocleido-mastoid & pterygoid </li></ul><ul><li>Post .: tip of spinous process </li></ul>
  30. 36. How to define the treatment targets? <ul><li>Medial : c-spine body and pharyngeal lumen </li></ul><ul><li>Lateral : edge of sternocleidomastoid m. or medial 2/3 </li></ul><ul><li>Post .: tip of spinous process </li></ul>
  31. 37. How to decide the doses to the different targets and different critical organs? <ul><li>SMART : simultaneous modulated accelerated radiation therapy, Dr. Butler and Dr. Teh, 1999 </li></ul><ul><li>SIB : simultaneous integrated boost, Dr. Mohan and Dr. Wu, 2000 </li></ul>
  32. 38. SMART IMRT Schedule <ul><li>Primary target: 2.4 Gy per fraction </li></ul><ul><li>Secondary target: 2.0 Gy </li></ul><ul><li>Butler EB, Teh BS, Grant WH et al: SMART (simultaneous modulated accelerated radiation therapy) boost: A new accelerated fractionation schedule for the treatment of head and neck cancer with intensity modulated radiotherapy. Int J Radiat Oncol Biol Phys, v45, no.1, pp21-32, 1999 </li></ul>
  33. 39. SIB IMRT Schedule <ul><li>Primary target: 2.2 Gy per fraction </li></ul><ul><li>Secondary target: 1.8 Gy </li></ul><ul><li>Mohan R, Wu Q, Maning M and Schmidt-Ullrich R: Radiobiological considerations in the design of fractionation strategies for intensity-modulated radiation therapy of head and neck cancers. Int J Radiat Oncol Biol Phys, v46, No.3, pp619-630, 2000 </li></ul>
  34. 40. Is the IMRT really better than conventional or 3-D conformal radiotherapy?
  35. 41. IMRT Two opposed
  36. 42. <ul><li>IMRT Two opposed </li></ul>
  37. 43. <ul><li>IMRT Two opposed </li></ul>
  38. 44. <ul><li>DVH of 3-D conformal radiotherapy </li></ul>
  39. 45. <ul><li>DVH of intensity-modulated radiotherapy </li></ul>
  40. 46. <ul><li>Lower skin reaction with IMRT technique </li></ul>
  41. 47. IMRT must be applied very carefully!
  42. 48. <ul><li>Dawson LA, Anzai Y, Marsh L et al: Patterns of local-regional recurrence following parotid-sparing conformal and segmental intensity-modulated radiotherapy for head and neck cancer. Int J Radiat Oncol Biol Phys, V46, No.5, pp1117-1126, 2000 </li></ul>
  43. 50. Thank You!

×