M D Anderson
             Cancer Center
                Orlando
TomoTherapy’s Implementation of
Image-guided Adaptive Radi...
Today’s Lecture

• Introduction to helical tomotherapy

• Image guidance with TomoTherapy

• Adaptive radiation therapy wi...
Introduction to helical
     Tomotherapy
TomoTherapy

• Helical tomotherapy process to deliver IMRT


• Same hardware can be used to image (MVCT)
  patient (IGRT)
TomoTherapy

Fan beam,
continuously                 Patient
  rotates




                            Tumor
              ...
TomoTherapy




Divides beam into 64 beamlets

each beamlet can be on/off
TomoTherapy

Fan beam,
continuously                 Patient
  rotates




                            Tumor
              ...
TomoTherapy

Fan beam,
continuously                 Patient
  rotates




                             Tumor
TomoTherapy

Fan beam,
continuously                 Patient
  rotates




                            Tumor
              ...
Fan Beam          lateral




                              longitudinal



400 mm     10, 25, or 50 mm
 lateral      long...
Helical Tomotherapy ?




       from: W. Kalender, Computed Tomography: Fundamentals,
             System Technology, Ima...
Delivery

- 51 projections per
  rotation: 360 º /51=7 º


-Temporal modulation
 leaf opening time
 during projection
Head + Neck      Delivery Instructions
                     (Sinograms)
             P
             r
                   P...
The TomoTherapy unit at M D Anderson Orlando
The TomoTherapy unit at M D Anderson Orlando
Megavoltage CT images
                     6 MV Accelerator
                     (tuned to 3.5 MV for MVCT)



           ...
Patient Images: Prostate

Diagnostic (kV) CT   Tomotherapy (MV) CT
Patient Images: Head and Neck
Diagnostic (kV) CT   Tomotherapy (MV) CT
Image guidance with
the TomoTherapy system
Terminology

    Image-guided Radiation Therapy (IGRT):

    Use images to position patient
    -Portal images, Ultrasound...
Image (MVCT) Quality ?
Helical Tomotherapy:
MVCT Imaging Performance Characterization

• AAPM CT Phantom [Cardinal Health, Hicksville, NY].
  • N...
Noise
                              Expressed as % of µwater
                                                  Mean ROI   ...
Uniformity
       Maximum Peripheral to Central Deviation
        Matrix        Pitch   Maximum             Uniformity    ...
Spatial Resolution: Qualitative Determination
       256x256 matrix                     512x512 matrix

      No holes res...
Meeks et al.,
                                        Contrast Detail                        Med Phys, 32,
               ...
Patient Images
MVCT Dose
             1.10         Multiple Scan Average Dose in 20-cm diameter phantom

             1.00
              ...
Summary

•   Uniformity is comparable to diagnostic CT scanners while noise is
    worse

•   Spatial resolution using 512...
Average In-Room Times


•   5 minutes for setup
                           IGRT
•   3-5 minutes MVCT scan
•   5 minutes re...
Prostate IGRT: Helical   Transverse, not aligned
    Tomotherapy
Prostate IGRT: Helical   Transverse, aligned
    Tomotherapy
Prostate IGRT: Helical   Sagittal, aligned
    Tomotherapy
Image Registration for Prostate cases ?

Fiducial marker based
                             Anatomy based




   Contour b...
Prostate alignment study


RT: Marker, Anatomy, Contour
MD: Marker, Anatomy, Contour

       112 image pairs
         3 pa...
RT vs MD registration
            Difference ≥ 5 mm


Marker          Anatomy             Contour


A/P: 1 %       A/P: 5 ...
RT vs MD registration
            Difference ≥ 3 mm


 Marker        Anatomy             Contour


A/P: 2 %       A/P: 15 ...
Conclusions of alignment study




Implanted marker based alignment have
least inter-user variability


 Anatomy-based ali...
Head and Neck alignment: bony anatomy


                     MVCT




                                   Spinal Cord
     ...
IGRT and ART,
do we need both ?
Daily-IGRT, why ART ?
 Deformation in the Pelvis
Same patient, different days




 Dosimetric consequence ?
Progressive deformation
Barker (2004): 14 H+N patients, 13-20 repeat CT, in-room CT


               Observation of tumor ...
Progressive deformation
Barker (2004): 14 H+N patients, 13-20 repeat CT, in-room CT



          Observation of parotid sh...
kVCT vs. end-of-treatment MVCT
      Dosimetric consequence ?
kVCT:
PTV
SC
Adaptive Radiation Therapy
  with the TomoTherapy
          system
Terminology
   Adaptive Radiation Therapy (ART):

   Use information from images to change subsequent
   treatments

   -C...
Adaptive Radiation Therapy:
                                  need accurate HU
                                      numbe...
Accuracy of MVCT numbers
Need MVCT to electron density calibration

kVCT                  MVCT




        RMI, Model 467, CT to electron density
 ...
MVCT to electron density calibration curves

     kVCT                      MVCT
MVCT Integrity ?


     Does the calibration change with time ?

Does calibration change with phantom arrangement ?

 Does...
MVCT Integrity ?
Does the calibration change with time ?
MVCT Integrity ?
Does the calibration change with phantom arrangement ?
MVCT Integrity ?
Does the calibration change with phantom arrangement ?
MVCT Integrity ?
Does the calibration change with MVCT pitch ?
Dose re-computation end-to-end tests
             Rigid phantom
              kVCT scan
            Fictitious target
    ...
Dose re-computation end-to-end tests
Dose re-computation end-to-end tests


                              all target D95
                             are withi...
Dose re-computation end-to-end tests

           Deformed anatomy ?




Plan 2           Plan 2,       Plan 2,
           ...
Dose re-computation end-to-end tests



                Meas. Diff (%)   Re-calc. Diff (%)

Plan 1, Def 1       + 2.7     ...
Conclusions
 - MVCT numbers are reproducible
  MVCT to electron density calibration is reliable
 - Phantom end-to-end test...
Daily-IGRT, why ART ?
 Deformation in the Pelvis
Same patient, different days




 Dosimetric consequence ?
Evaluate dosimetric consequence:

           Dose Re-calculation

         Use pre-treatment MVCT



Recalculate plan base...
Deformation in the Pelvis
  Evaluate dosimetric consequence

Obtain MVCT   MVCT contours   Dose recalculation
Deformation in the Pelvis

                      Plan DVH

                    39 “true” DVHs
Deformation in the Pelvis

                              Plan DVH

                           39 “true” DVHs




1) Requir...
Deformable image registration

Relate voxel location x to its location in the second
image (at a later time t) using a dis...
MVCT to kVCT
 deformable image registration
Algorithm requires same HU for same voxel
in MVCT and kVCT

MVCT are noisier
=...
MVCT to kVCT
   deformable image registration
  Algorithm maps each MVCT voxel to kVCT

  Algorithm can map each kVCT voxe...
MVCT to kVCT
deformable image registration




   Lu et al. , Phys Med Biol, submitted, 2006
MVCT to kVCT
        deformable image registration
kVCT:
PTV
SC


MVCT:
 PTV
 SC
Accuracy of automatic H+N MVCT
                                contours ?
  Spinal Cord: Automatic vs. manual contours,
  ...
Accuracy of automatic H+N MVCT
             contours ?
Parotids: Visual inspection of automatic
contours




           kV...
Accuracy of automatic H+N MVCT
             contours ?
Parotids: Visual inspection of automatic
contours
- 6 patients, 150...
Automatic MVCT contouring


kVCT      Tx 1          Tx 7   Tx 15




       kVCT contours:
       MVCT contours:
Automatic MVCT contouring


kVCT       Tx 1      Tx 7     Tx 15




       Dosimetric consequence ?
Dosimetric consequence

     Tx 7                DVH




1.4 Gy
Parotid dose during treatment course
Numerical Analysis:

-6 patients, 150 MVCT scans

Conclusion:
At end of treatment: me...
Clinical example
73 year old Head and Neck patient:
PTV prescription: 70 Gy in 35 fractions
Clinical example
First 17 fractions:
Plan vs. deformable registration DVH
          after 17 fractions



         Rt.           Lt.
        Parotid       Paro...
Generate adaptive plan

-Obtain new kVCT scan of patient

-How to transfer dosimetry
information to new kVCT ?
Generate adaptive plan

-Use kVCT-kVCT deformable
registration to transfer original structures
to second kVCT

-Physician ...
Rt. Parotid DVH (after 17 Txs)


            Medium dose    High dose
             10-20 Gy       > 20 Gy

 Low dose
  0-1...
Parotid DVH




          Generate contour
          that corresponds to
          10-20 Gy region
Generate second plan

                 First Plan    TARGET
                 Second Plan


PAROTID
Patient completes treatment


         Daily scans
Daily deformable registration

      FULL COURSE
WHAT IF SCENARIOS….compare


-Original Plan P1(35)
-Plan 1 delivered for 17 fx + Plan 2 for 18 fx
 Planned to deliver with...
What if .. (Rt. Parotid DVH)

100

 90

 80
                                                    P1(35)
 70

 60

 50

 40
...
What if .. (Rt. Parotid DVH)

100

 90
                                               P1(35)
 80

 70
                    ...
What if .. (Rt. Parotid DVH)

100

 90                                            P1(35)

 80
                            ...
What if .. (Rt. Parotid DVH)

100

 90                                            P1(35)

 80                             ...
Conclusion

 Opportunities             Challenges
- Assess consequence      - When to adapt plan ?
  of deformation
      ...
Thanks !
MD Anderson:            TomoTherapy:
Sanford Meeks                   Gustavo Olivera

Tom Wagner              Jas...
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Adaptive Radiation Therapy With Tomo Therapy

  1. 1. M D Anderson Cancer Center Orlando TomoTherapy’s Implementation of Image-guided Adaptive Radiation Therapy Katja Langen, PhD Research supported by TomoTherapy Inc.
  2. 2. Today’s Lecture • Introduction to helical tomotherapy • Image guidance with TomoTherapy • Adaptive radiation therapy with TomoTherapy
  3. 3. Introduction to helical Tomotherapy
  4. 4. TomoTherapy • Helical tomotherapy process to deliver IMRT • Same hardware can be used to image (MVCT) patient (IGRT)
  5. 5. TomoTherapy Fan beam, continuously Patient rotates Tumor Healthy Organ
  6. 6. TomoTherapy Divides beam into 64 beamlets each beamlet can be on/off
  7. 7. TomoTherapy Fan beam, continuously Patient rotates Tumor Healthy Organ
  8. 8. TomoTherapy Fan beam, continuously Patient rotates Tumor
  9. 9. TomoTherapy Fan beam, continuously Patient rotates Tumor Healthy Organ
  10. 10. Fan Beam lateral longitudinal 400 mm 10, 25, or 50 mm lateral longitudinal
  11. 11. Helical Tomotherapy ? from: W. Kalender, Computed Tomography: Fundamentals, System Technology, Image Quality, Applications
  12. 12. Delivery - 51 projections per rotation: 360 º /51=7 º -Temporal modulation leaf opening time during projection
  13. 13. Head + Neck Delivery Instructions (Sinograms) P r Prostate -Typical gantry rotation: o 15-20 seconds j e c t -Typical treatment time: i Prostate: 5 Min o H+N: 7 Min n s 64 Leafs
  14. 14. The TomoTherapy unit at M D Anderson Orlando
  15. 15. The TomoTherapy unit at M D Anderson Orlando
  16. 16. Megavoltage CT images 6 MV Accelerator (tuned to 3.5 MV for MVCT) Primary Collimator ( 4 mm Slice Width) Binary MLC 85cm (all leafs open during MVCT) User can adjust: TF OV -Scan range C cm 40 -Pitch Approximately 50cm Courtesy of: TomoTherapy, Inc .
  17. 17. Patient Images: Prostate Diagnostic (kV) CT Tomotherapy (MV) CT
  18. 18. Patient Images: Head and Neck Diagnostic (kV) CT Tomotherapy (MV) CT
  19. 19. Image guidance with the TomoTherapy system
  20. 20. Terminology Image-guided Radiation Therapy (IGRT): Use images to position patient -Portal images, Ultrasound, CT-based Image-guided Radiation Therapy (IGRT) with TomoTherapy: Megavoltage CT (MVCT) based
  21. 21. Image (MVCT) Quality ?
  22. 22. Helical Tomotherapy: MVCT Imaging Performance Characterization • AAPM CT Phantom [Cardinal Health, Hicksville, NY]. • Noise • Uniformity • Spatial Resolution • Dosimetry • Multiple Scan Average Dose (MSAD) in 20 cm diameter acrylic phantom Meeks et al., Med Phys, 32, pp 2673
  23. 23. Noise Expressed as % of µwater Mean ROI ROI Standard Matrix Pitch Noise "CT #" Deviation 1.0 1024 25.4 2.7 256 1.6 1026 an worse th 25.4 2.7 - 2.4 1021lues ch va 25.3 2.7 t of pi 1.0 ependent 1028 35.4 3.7 nd 512 ix – i tr 1.6 1027 35.5 3.7 co n ma w ith re nners 2.4 1029 36.2 3.8 Increases CT sca c diag n o s ti 1.0 1025 43.2 4.5 768 1.6 1025 43.8 4.6 2.4 1026 43.3 4.6 AcQSim 1.0 1005 18 1.9 512 Meeks et al., Med Phys, 32, pp 2673
  24. 24. Uniformity Maximum Peripheral to Central Deviation Matrix Pitch Maximum Uniformity Mean Mean Peripheral Index Center Peripheral rs Variation (%) "CT" "CT" T sc anne 256 1.0 0.99 99.5 1015 s ti c 1025 C o iagn1027 1019 d 1.6 0.97 99.6 a ble to 2.4 1.03 99.5 compar 1013 1022 v a lues – 512 1.0 1.00 matrix 99.5 1020 1029 econ 1.6 h/r 0.90 99.6 1019 1028 f pitc ndent o 2.4 1.04 99.5 1021 1031 I ndepe 768 1.0 0.94 99.5 1019 1027 1.6 0.80 99.6 1019 1026 2.4 0.89 99.6 1019 1027 AcQSim 1.0 0.55 99.6 1006 1005 512 Meeks et al., Med Phys, 32, pp 2673
  25. 25. Spatial Resolution: Qualitative Determination 256x256 matrix 512x512 matrix No holes resolved Visible resolution ~1.5 mm Visible resolution > 1.75 mm 768x768 matrix Visible resolution ~1.25 mm Meeks et al., Med Phys, 32, pp 2673
  26. 26. Meeks et al., Contrast Detail Med Phys, 32, pp 2673 18 16 25.4 mm 14 19.1 mm 12 Diameter (mm) 12.7 mm 10 9.5 mm 8 6.4 mm 3.2 mm 6 Visible 5% difference 4 2 Not Visible 0 0 10 20 30 40 50 60 70 80 90 100 110 % Electron Density Difference
  27. 27. Patient Images
  28. 28. MVCT Dose 1.10 Multiple Scan Average Dose in 20-cm diameter phantom 1.00 “Fine” scan ~ 1 cGy 0.90 0.80 0.70 MSAD (cGy) Measured Values Norm to Pitch 1 0.60 0.50 “Coarse” scans < 0.5 cGy 0.40 0.30 0.20 0.10 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Pitch Meeks et al., Med Phys, 32, pp 2673
  29. 29. Summary • Uniformity is comparable to diagnostic CT scanners while noise is worse • Spatial resolution using 512x512 matrix is ~1.5 mm • Dose: ~1 cGy for “fine” setting (pitch of 1) ; dose decreases with “looser” pitch • Image Quality is acceptable for patient alignment, and is also acceptable for delineation of many soft tissue structures. Meeks et al., Med Phys, 32, pp 2673
  30. 30. Average In-Room Times • 5 minutes for setup IGRT • 3-5 minutes MVCT scan • 5 minutes reconstruction and registering MVCT to KVCT and shift patient • 5-10 minutes beam on time • 5 minutes assist patient out
  31. 31. Prostate IGRT: Helical Transverse, not aligned Tomotherapy
  32. 32. Prostate IGRT: Helical Transverse, aligned Tomotherapy
  33. 33. Prostate IGRT: Helical Sagittal, aligned Tomotherapy
  34. 34. Image Registration for Prostate cases ? Fiducial marker based Anatomy based Contour based
  35. 35. Prostate alignment study RT: Marker, Anatomy, Contour MD: Marker, Anatomy, Contour 112 image pairs 3 patients Langen et al., IJROBP, 62, pp 1517
  36. 36. RT vs MD registration Difference ≥ 5 mm Marker Anatomy Contour A/P: 1 % A/P: 5 % A/P: 17 % S/I: 2 % S/I: 10 % S/I: 31 % Lat.: 1 % Lat.: 0 % Lat.: 3 % Langen et al., IJROBP, 62, pp 1517
  37. 37. RT vs MD registration Difference ≥ 3 mm Marker Anatomy Contour A/P: 2 % A/P: 15 % A/P: 48 % S/I: 12 % S/I: 32 % S/I: 52 % Lat.: 2 % Lat.: 3 % Lat.: 24 % Langen et al., IJROBP, 62, pp 1517
  38. 38. Conclusions of alignment study Implanted marker based alignment have least inter-user variability Anatomy-based alignments outperform contour-based alignments Langen et al., IJROBP, 62, pp 1517
  39. 39. Head and Neck alignment: bony anatomy MVCT Spinal Cord Base of skull not aligned aligned
  40. 40. IGRT and ART, do we need both ?
  41. 41. Daily-IGRT, why ART ? Deformation in the Pelvis Same patient, different days Dosimetric consequence ?
  42. 42. Progressive deformation Barker (2004): 14 H+N patients, 13-20 repeat CT, in-room CT Observation of tumor regression Barker et al. , IJROBP, 59, pp 960, 2004
  43. 43. Progressive deformation Barker (2004): 14 H+N patients, 13-20 repeat CT, in-room CT Observation of parotid shrinkage and migration Barker et al. , IJROBP, 59, pp 960, 2004
  44. 44. kVCT vs. end-of-treatment MVCT Dosimetric consequence ? kVCT: PTV SC
  45. 45. Adaptive Radiation Therapy with the TomoTherapy system
  46. 46. Terminology Adaptive Radiation Therapy (ART): Use information from images to change subsequent treatments -Change margin based on observed setup/organ motion -Use images to evaluate dosimetry (dose-guided, dose compensation…) Adaptive Radiation Therapy (ART) with TomoTherapy: Using MVCT images to evaluate dosimetry on daily basis
  47. 47. Adaptive Radiation Therapy: need accurate HU numbers Acquire MVCT ↓ Recalculate dose distribution on MVCT ↓ Add dose distribution to calculate cumulative dose ↓ Compare with plan ↓ need deformable Adapt plan image registration
  48. 48. Accuracy of MVCT numbers
  49. 49. Need MVCT to electron density calibration kVCT MVCT RMI, Model 467, CT to electron density phantom
  50. 50. MVCT to electron density calibration curves kVCT MVCT
  51. 51. MVCT Integrity ? Does the calibration change with time ? Does calibration change with phantom arrangement ? Does the calibration change with MVCT pitch ?
  52. 52. MVCT Integrity ? Does the calibration change with time ?
  53. 53. MVCT Integrity ? Does the calibration change with phantom arrangement ?
  54. 54. MVCT Integrity ? Does the calibration change with phantom arrangement ?
  55. 55. MVCT Integrity ? Does the calibration change with MVCT pitch ?
  56. 56. Dose re-computation end-to-end tests Rigid phantom kVCT scan Fictitious target Generate treatment plan MVCT scan phantom Re-calculate dose in MVCT Compare plan DVH with recalculated DVH Expect agreement !!!
  57. 57. Dose re-computation end-to-end tests
  58. 58. Dose re-computation end-to-end tests all target D95 are within 0.5 %
  59. 59. Dose re-computation end-to-end tests Deformed anatomy ? Plan 2 Plan 2, Plan 2, Deformation 1 Deformation 2 Point of ion chamber measurement
  60. 60. Dose re-computation end-to-end tests Meas. Diff (%) Re-calc. Diff (%) Plan 1, Def 1 + 2.7 +2.9 Plan 1, Def 2 -10.5 -9.3 Plan 2, Def 1 +3.3 +3.2 Plan 1, Def 2 -11.5 -10.8
  61. 61. Conclusions - MVCT numbers are reproducible MVCT to electron density calibration is reliable - Phantom end-to-end test results are typically within 1 % of plan results MVCT images can be used for reliable dose computations Langen et al.: Use of mega voltage CT (MVCT) images for dose computations. PMB, 50, pp 4259
  62. 62. Daily-IGRT, why ART ? Deformation in the Pelvis Same patient, different days Dosimetric consequence ?
  63. 63. Evaluate dosimetric consequence: Dose Re-calculation Use pre-treatment MVCT Recalculate plan based on planned MLC pattern Recalculate Dose on MVCT image
  64. 64. Deformation in the Pelvis Evaluate dosimetric consequence Obtain MVCT MVCT contours Dose recalculation
  65. 65. Deformation in the Pelvis Plan DVH 39 “true” DVHs
  66. 66. Deformation in the Pelvis Plan DVH 39 “true” DVHs 1) Requires manual contouring 2) Need deformable image registration to calculated the cumulative DVH
  67. 67. Deformable image registration Relate voxel location x to its location in the second image (at a later time t) using a displacement vector u(x,t) x’(x,t)=x+u(x,t) Algorithm minimizes ∑u and differences in HU units Lu et al. , Phys Med Biol, 49, pp 3067, 2004
  68. 68. MVCT to kVCT deformable image registration Algorithm requires same HU for same voxel in MVCT and kVCT MVCT are noisier => apply edge-preserving smoothing => MVCT numbers ≠ kVCT numbers intensity histogram calibration Lu et al. , Phys Med Biol, submitted, 2006
  69. 69. MVCT to kVCT deformable image registration Algorithm maps each MVCT voxel to kVCT Algorithm can map each kVCT voxel to MVCT ⇒ can be used for automatic contouring of MVCT ⇒ automatically generated MVCT contours can be used to visualize deformation map Lu et al. , Phys Med Biol, submitted, 2006
  70. 70. MVCT to kVCT deformable image registration Lu et al. , Phys Med Biol, submitted, 2006
  71. 71. MVCT to kVCT deformable image registration kVCT: PTV SC MVCT: PTV SC
  72. 72. Accuracy of automatic H+N MVCT contours ? Spinal Cord: Automatic vs. manual contours, Compare dose-based end points: Dmax, Dmean 1 Dmax Dmean 1.4 Dose (Gy) Dose (Gy) 0.8 1.2 Automatic Manual Automatic Manual 1 0.6 0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 Teatment fraction Treatment fraction 3 patients: Dmax ratio: 1.1 ± 3.5 % Dmean ratio: 0.1 ± 2.5 % Moderated Poster: AAPM 06, Langen et al.
  73. 73. Accuracy of automatic H+N MVCT contours ? Parotids: Visual inspection of automatic contours kVCT contours: MVCT contours:
  74. 74. Accuracy of automatic H+N MVCT contours ? Parotids: Visual inspection of automatic contours - 6 patients, 150 MVCT scans, 2 physician Conclusion: The parotid contours generated by the deformable algorithm correlate with the location of these structures on the daily MVCT images. Submitted to ASTRO 06, Manon et al.
  75. 75. Automatic MVCT contouring kVCT Tx 1 Tx 7 Tx 15 kVCT contours: MVCT contours:
  76. 76. Automatic MVCT contouring kVCT Tx 1 Tx 7 Tx 15 Dosimetric consequence ?
  77. 77. Dosimetric consequence Tx 7 DVH 1.4 Gy
  78. 78. Parotid dose during treatment course Numerical Analysis: -6 patients, 150 MVCT scans Conclusion: At end of treatment: mean parotid dose was on average 7.5 Gy higher than planned Range:1.6-16.4 Gy Submitted to ASTRO 06, Manon et al.
  79. 79. Clinical example 73 year old Head and Neck patient: PTV prescription: 70 Gy in 35 fractions
  80. 80. Clinical example First 17 fractions:
  81. 81. Plan vs. deformable registration DVH after 17 fractions Rt. Lt. Parotid Parotid 15 Gy 17 Gy
  82. 82. Generate adaptive plan -Obtain new kVCT scan of patient -How to transfer dosimetry information to new kVCT ?
  83. 83. Generate adaptive plan -Use kVCT-kVCT deformable registration to transfer original structures to second kVCT -Physician reviewed structures -Generate new plan Limit dose to over-dosed parotid region
  84. 84. Rt. Parotid DVH (after 17 Txs) Medium dose High dose 10-20 Gy > 20 Gy Low dose 0-10 Gy Dose difference mostly in 10-20 Gy region
  85. 85. Parotid DVH Generate contour that corresponds to 10-20 Gy region
  86. 86. Generate second plan First Plan TARGET Second Plan PAROTID
  87. 87. Patient completes treatment Daily scans Daily deformable registration FULL COURSE
  88. 88. WHAT IF SCENARIOS….compare -Original Plan P1(35) -Plan 1 delivered for 17 fx + Plan 2 for 18 fx Planned to deliver with adaptive RT D1(17)+P2(18) -Actual delivery (Plan 1-17 fx and Plan 2-18 fx) D1(17)+D2(18) -without adaptive RT, Plan 1 only D1(35)
  89. 89. What if .. (Rt. Parotid DVH) 100 90 80 P1(35) 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 Dose (Gy)
  90. 90. What if .. (Rt. Parotid DVH) 100 90 P1(35) 80 70 D1(17)+P2(18) 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 Dose (Gy)
  91. 91. What if .. (Rt. Parotid DVH) 100 90 P1(35) 80 D1(17)+P2(18) 70 60 D1(17)+D2(18) 50 40 30 20 10 0 0 10 20 30 40 50 60 70 Dose (Gy)
  92. 92. What if .. (Rt. Parotid DVH) 100 90 P1(35) 80 D1(17)+P2(18) 70 D1(17)+D2(18) 60 D1(35) 50 40 30 20 10 0 0 10 20 30 40 50 60 70 Dose (Gy)
  93. 93. Conclusion Opportunities Challenges - Assess consequence - When to adapt plan ? of deformation - How often ? - Correct differences between delivered and - Verify accuracy of planned dose in adaptive deformable registration Plan - Shrinking volumes ?
  94. 94. Thanks ! MD Anderson: TomoTherapy: Sanford Meeks Gustavo Olivera Tom Wagner Jason Haimerl Twyla Willoughby Ken Ruchala Omar Zeidan Weigu Lu Amish Shah Sam Jeswani Arati Limaye Quan Chen Patrick Kupelian Eric Schnarr Rafael Mañon Daniel Buchholz Alan Forbes Wayne Jenkins
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