Igrt for cervical cancer feb 8 2013 920 a cancer ci 2013
Apollo hydbd feb8 2013 (cancer ci 2013) p. mahadev md
1. CYBERKNIFE
SRS & SBRT
P.Mahadev MD DNB
Apollo Speciality Cancer Hospital
Chennai
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. 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
8. Robot is capable of delivering radiation from
different 100 nodes, with each node is capable of
giving a maximum 12 different beams.
Usage of these nodes depends on the treatment room
constraints
9.
10. The table consists of 12 fixed cones and housings of
Fixed and Iris Collimator
Laser Sensor
Collimator sizes(mm): 5, 7.5, 10, 12.5, 15, 20, 25, 30,
35, 40, 50, 60
11.
12.
13. There are two essential features of the
CyberKnife system that sets it apart from other
stereotactic radiosurgery methods.
14. 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
15. 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
16. 6D_ Skull tracking system:
used for intra-cranial lesions up to C2
Bony anatomy of the skull is used as reference for
tracking
17.
18. Fiducial tracking system:
used for soft tissues, where gold fiducials
can be implanted.
Minimum of 3 nos. to be implanted
19. 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
20.
21. • 790 fiducials
• 85% successfully placed
• 2 Patients developed pneumothorax
• 6 fiducials migrated- 3 in lung, 2 in
liver& 1 in prostate
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32. 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
33.
34. Imaging and Tumor Targeting
Traditional IGRT daily set-up imaging maybe
inadequate for
sub-millimeter accuracy
Immobilization
Breath Holding
35. Imaging and Tumor Targeting
Traditional IGRT daily set-up imaging maybe
inadequate for
sub-millimeter accuracy
Immobilization
Breath Holding
Gating
36. 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.
37. 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
38. Two features to form the basis for accuracy
Fiducials, implanted prior to Optical markers on a special
treatment patient vest
39. 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
40. 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
41. This process repeats throughout the treatment, updating and correcting beam delivery based upon
the patient’s current breathing pattern
displacement
displacement
time time
42.
43.
44.
45.
46.
47. 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
48.
49. The appropriate tracking method has to be chosen
during planning itself
No treatment is possible without planning and proper
tracking method
50. 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
51. Planning System (MultiPlan) uses inverse
planning algorithm with following options
1. Conformal Planning
2. Sequential optimization
The system provides the user the option of
using either ray tracing method or Monte Carlo
52. 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
53. 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
54.
55.
56.
57.
58. 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
59. T1&T2 NSCLC – inoperable or medical
contraindication or patient refuses surgery, ideal
lesion <3cm & peripheral location
oligometastasis
60.
61.
62.
63.
64.
65. 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
66.
67. RADIOBIOLOGICAL RATIONALE: LOW
APLHA/BETA RATIO
GOOD RESULTS OBTAINED WITH HDR
brachytherapy
LESS INVASIVE THAN BRACHYTHERAPY
68.
69.
70.
71. 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
72.
73.
74.
75. 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
77. MEDIAN FU 2 YR MEDIAN
BIOCHEMI PSA
CAL NADIR
PFS
HDR 22 MONTHS 94% 0.8
CK 16 MONTHS 96% 1.0
IMRT/IGRT 48 MONTHS 89% 0.9
78.
79.
80. 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
81.
82.
83.
84.
85.
86.
87.
88. Intramedullary spinal cord AVM’s only
Not amenable to microsurgical excision/embolisatio
symptomatic
90. Spine tracking
1.25 mm contrast enhanced axial CT
Target volume traced on CT in cojunction with:MRI
2D/3D spinal angio
91. 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
94. 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
95.
96.
97. 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
98.
99.
100. 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
101. 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 a
primary treatment modality
Long-term tumor control in 88% of lesions that failed other therapies
102. 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