Gregoire H&N

4,779 views

Published on

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

No Downloads
Views
Total views
4,779
On SlideShare
0
From Embeds
0
Number of Embeds
30
Actions
Shares
0
Downloads
382
Comments
0
Likes
5
Embeds 0
No embeds

No notes for slide

Gregoire H&N

  1. 1. Conformal radiotherapy and IMRT in Head and Neck Tumors The “academic” view point
  2. 2. Target volumes in Radiation Oncology: ICRU definition • Gross Tumor Volume: GTV • Clinical Target Volume: CTV • Planning Target Volume: PTV ICRU report 62, 1999
  3. 3. Immobilization of Head & Neck patients l 15 head & neck tumors l 15 brain tumors l 3 different masks (3, 4 & 5 FP) l 3 fictitious isocenters
  4. 4. Immobilization of Head & Neck patients l 915 portals images acquired. l 98 % analysed. l Total Displacement. u SIM - EPIDi l Systematic Displacement. u M(SIM - EPIDi) l Random Displacement. u (SIM - EPIDi) - [ M(SIM - EPIDi)] l Intraobserver variation: 0.7 mm (1 Sd).
  5. 5. 1.0 Cumulative incidence 0.9 0.8 Head 0.7 0.6 (3-5 FP) Total 3-D 0.5 0.4 0.3 deviations 0.2 0.1 0.0 0 1 2 3 4 5 6 7 8 9 10 Deviation from the isocenter (mm) 1 1.0 0.9 Cumulative incidence Shoulder Cumulative incidence 0.9 0.8 0.8 Neck 0.7 0.7 (4 & 5 FP) 0.6 (3-5 FP) 0.6 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 0.0 0 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Deviation from the isocenter (mm) Deviation of the isocenter (mm)
  6. 6. Characteristics of current imaging modalities CT MRI PET fMRI Image characteristics skin contour + ± ± - soft-tissue contrast ± + - - bone contrast + ± - - air contrast + ± ± - metallic artefacts + ± - ± movement artefacts - + ± + Machine characteristics large “tunnel” size + - - - distortion - + ± + electron density + - ± - multiplannar imaging - + ± +
  7. 7. Conformal radiotherapy and IMRT in Head and Neck Tumors Image acquisition • Dual detector spiral CT • 2.7 mm collimation, pitch 0.7, reconstruction of 2 - 2.5 mm • Display matrix of 512 x 512 pixels • Contrast enhancement (interstitial and blood vessel contrast)
  8. 8. Conformal radiotherapy: reference coordinates
  9. 9. Conformal radiotherapy: 3D reconstruction
  10. 10. Conformal radiotherapy: 3D reconstruction
  11. 11. Conformal radiotherapy: image display
  12. 12. The present … which CTV for the neck ? Cervical lymph node groups (MSKCC classification) Adopted by the Academy’s Committee for Head & Neck Surgery and Oncology Robbins et al, 1991
  13. 13. Conformal radiotherapy and IMRT in Head and Neck Tumors Definition of the extend of the CTV in the neck State of the art • Predictive pattern of lymph node involvement in HNSCC • Selective neck treatment (irradiation or dissection) for selected N stage
  14. 14. The present …CT-based delineation of lymph node levels in the neck Ia Ib VI III RP V II Grégoire et al., 2000
  15. 15. Conformal radiotherapy: volume delineation
  16. 16. Conformal radiotherapy: volume delineation
  17. 17. Conformal radiotherapy: Beam selection
  18. 18. B E V
  19. 19. Conformal radiotherapy: Dose distribution
  20. 20. Conformal radiotherapy: Dose distribution
  21. 21. Conformal radiotherapy: Dose volume histogram
  22. 22. Conformal radiotherapy: Dose volume histogram
  23. 23. Conformal radiotherapy and IMRT in Head and Neck Tumors Mr H. D. (77 years): T3-N0-M0 base of tongue (ICD0-10: C01)
  24. 24. Conformal radiotherapy and IMRT in Head and Neck Tumors Mr H. D. (77 years): T3-N0-M0 base of tongue (ICD0-10: C01) Target volumes • T: CTV1: GTV + 1.5 cm margin CTV2: GTV + 0.5 cm margin PTV1&2 : CTV + 4 mm • N:CTV: R & L LII - IV PTV: CTV + 4 mm Dose prescription • T: PTV1: 50 Gy, 25x2 Gy PTV2: 70 Gy, 35x2 Gy • N:PTV: 50 Gy, 25x 2Gy
  25. 25. Conformal radiotherapy and IMRT in Head and Neck Tumors “Antique” (7 fields) Rx 6 MV Rx 6 MV 40 Gy 30 Gy Elect 8 MeV Rx 6 MV 10 Gy 50 Gy
  26. 26. Conformal radiotherapy and IMRT in Head and Neck Tumors Dose (Gy) at various organs at risk Antique Middle-age Art nouveau PTV 55 Gy Dmean 63.2 60.1 59.2 Dmax 79,1 76.6 74.6 Dmin 10.0 39.1 44.4 SD 10.2 9.5 8.1 PTV 70 Gy Dmean 72.4 71.7 70.6 Dmax 76.9 76.5 74.6 Dmin 67.4 65.2 67.0 SD 1.8 2.1 1.5 L parotid Dmedian 68.7 52.1 50.7 Dmax 72.8 72.5 71.8 Dmin 46.4 8.4 5.4 SD 7.6 12.2 15.5 R parotid Dmedian 69.6 65.7 40.6 Dmax 72.9 72.6 55.9 Dmin 62.1 4.4 3.6 SD 1.7 24.9 16.7
  27. 27. Conformal radiotherapy and IMRT in Head and Neck Tumors Dose (Gy) at various organs at risk Antique Middle-age Art nouveau Spinal cord Dmean 22.8 19.6 22.7 Dmax 43.0 41.9 47.6 Dmin 5.5 3.3 2,7 SD 16.0 16.1 18.0 Mandibula Dmedian 71.5 68.9 60.5 Dmax 76.8 74.5 72.2 Dmin 51.1 4.8 3.7 SD 2.2 22.0 17.4 Internal contour Dmedian 41.6 13.6 19.3 Dmax 79.2 76.6 74.6 Dmin 2.0 1.2 1.1 SD 21.5 23.4 22.2
  28. 28. Conformal radiotherapy and IMRT in Head and Neck Tumors “Middle Age” (9 fields) Rx 6 MV Rx 6 MV 40 Gy 10 Gy Elect 8 MeV Rx 6 MV Rx 6 MV 10 Gy 20 Gy 50 Gy
  29. 29. Conformal radiotherapy and IMRT in Head and Neck Tumors “Middle Age” (9 fields) Rx 6 MV Rx 6 MV 40 Gy 10 Gy Elect 8 MeV Rx 6 MV Rx 6 MV 10 Gy 20 Gy 50 Gy
  30. 30. Conformal radiotherapy and IMRT in Head and Neck Tumors Dose (Gy) at various organs at risk Antique Middle-age Art nouveau PTV 55 Gy Dmean 63.2 60.1 59.2 Dmax 79,1 76.6 74.6 Dmin 10.0 39.1 44.4 SD 10.2 9.5 8.1 PTV 70 Gy Dmean 72.4 71.7 70.6 Dmax 76.9 76.5 74.6 Dmin 67.4 65.2 67.0 SD 1.8 2.1 1.5 L parotid Dmedian 68.7 52.1 50.7 Dmax 72.8 72.5 71.8 Dmin 46.4 8.4 5.4 SD 7.6 12.2 15.5 R parotid Dmedian 69.6 65.7 40.6 Dmax 72.9 72.6 55.9 Dmin 62.1 4.4 3.6 SD 1.7 24.9 16.7
  31. 31. Conformal radiotherapy and IMRT in Head and Neck Tumors Dose (Gy) at various organs at risk Antique Middle-age Art nouveau Spinal cord Dmean 22.8 19.6 22.7 Dmax 43.0 41.9 47.6 Dmin 5.5 3.3 2,7 SD 16.0 16.1 18.0 Mandibula Dmedian 71.5 68.9 60.5 Dmax 76.8 74.5 72.2 Dmin 51.1 4.8 3.7 SD 2.2 22.0 17.4 Internal contour Dmedian 41.6 13.6 19.3 Dmax 79.2 76.6 74.6 Dmin 2.0 1.2 1.1 SD 21.5 23.4 22.2
  32. 32. Conformal radiotherapy and IMRT in Head and Neck Tumors “Art nouveau” (10 fields, 12 segments ) SRAO SLAO Post. Seg. 1 Post. Seg. 2 Rx 6 MV 50 Gy RPO LPO Ant. …
  33. 33. Conformal radiotherapy and IMRT in Head and Neck Tumors “Art nouveau” (11 fields, 12 segments ) Ant. RAO LPO Rx 6 MV 20 Gy LAO1 LAO2
  34. 34. Conformal radiotherapy and IMRT in Head and Neck Tumors Dose (Gy) at various organs at risk Antique Middle-age Art nouveau PTV 55 Gy Dmean 63.2 60.1 59.2 Dmax 79,1 76.6 74.6 Dmin 10.0 39.1 44.4 SD 10.2 9.5 8.1 PTV 70 Gy Dmean 72.4 71.7 70.6 Dmax 76.9 76.5 74.6 Dmin 67.4 65.2 67.0 SD 1.8 2.1 1.5 L parotid Dmedian 68.7 52.1 50.7 Dmax 72.8 72.5 71.8 Dmin 46.4 8.4 5.4 SD 7.6 12.2 15.5 R parotid Dmedian 69.6 65.7 40.6 Dmax 72.9 72.6 55.9 Dmin 62.1 4.4 3.6 SD 1.7 24.9 16.7
  35. 35. Conformal radiotherapy and IMRT in Head and Neck Tumors Dose (Gy) at various organs at risk Antique Middle-age Art nouveau Spinal cord Dmean 22.8 19.6 22.7 Dmax 43.0 41.9 47.6 Dmin 5.5 3.3 2,7 SD 16.0 16.1 18.0 Mandibula Dmedian 71.5 68.9 60.5 Dmax 76.8 74.5 72.2 Dmin 51.1 4.8 3.7 SD 2.2 22.0 17.4 Internal contour Dmedian 41.6 13.6 19.3 Dmax 79.2 76.6 74.6 Dmin 2.0 1.2 1.1 SD 21.5 23.4 22.2
  36. 36. Conformal radiotherapy and IMRT in Head and Neck Tumors Forward planning IMRT • « human optimization » Inverse planning IMRT • Dose-volume constraints & weights for PTV and OARs • optimization algorithms • Penalty function
  37. 37. Inverse planning IMRT for Head and Neck Tumors Cummulative % of MUs l Spare cord Segment # l Spare left parotid 1 6. l 15 segments l 10 levels Courtesy of C. Field
  38. 38. Inverse planning IMRT for Head and Neck Tumors PTV Spared parotid gland Courtesy of C. Field
  39. 39. Parotid gland function lemon juice 370 MBq 99mTc-pertechnetate
  40. 40. Parotid gland function Objective assessment 100 90 R= 0,77 Maximum secretion (%) 80 70 60 50 40 30 20 Bilateral irradiation 10 Unilateral irradiation 0 0 10 20 30 40 50 60 70 Mean parotid dose (Gy)
  41. 41. Conformal radiotherapy and IMRT in Head and Neck Tumors Duration of treatment planning procedure 2D planning Forward planning Inverse planning (St-Luc) (Edmonton Cancer center) Volume delineation 0 - 0.25h 2 - 3h 1 - 1.5h Planning 0.25h 2 - 8h 1 - 2h Individualized QC 0h 0.25h 1h Treatment (per session) 10 - 15 min 20 - 25 min 15 min
  42. 42. Conformal radiotherapy and IMRT in Head and Neck Tumors Definition of the extend of the CTV in the neck State of the art • Predictive pattern of lymph node involvement in HNSCC • Selective neck treatment (irradiation or dissection) for selected N stage

×