4. Outline
⢠Concepts
⢠IGRT
â D fi d
Defined
â Technologies
⢠Applications
UAB Women and Infants Center and
Hazelrig-Salter R di ti Oncology Facility
H l i S lt Radiation O l F ilit
5. Big Picture Concepts
Big Picture Concepts
⢠Radiation penetrates all tissues
Radiation penetrates all tissues
⢠Radiation can destroy all tissues (normalÂ
and tumor)
and tumor)
⢠Therapeutic ratio:
Probability of tumor control
Probability of normal tissue toxicity
⢠Ideal: Maximize tumor kill, spare normalÂ
p
tissue, and preserve function
6. Big Picture Concepts
Big Picture Concepts
⢠Factors involved in therapeutic ratio:
⢠Tumor delineation: CT, PET, MRI, SPECT
⢠Precision dose distribution: Brachy, SRS/SBRT, IMRT,Â
Protons Adaptation
p
⢠Accurate Delivery:  Immobilization and guidanceÂ
(IGRT)
⢠F ti
Fractionation and Total dose
ti dT t ld
⢠Dose per fraction
, , / , p
⢠Dose rate: LDR, HDR, SRS/BT, RapidArcÂ
⢠Radiation modifiers: Radiation protectors and sensitizers
⢠Tumor Type
⢠Real Estate (Anatomical site): Location, location, location
7. Big Picture Concepts
Big Picture Concepts
Precision Accuracy
⢠âReproducibilityâ ⢠âVeracityâ
⢠Narrow clustering of hits
g ⢠Closeness of hits to target
Closeness of hits to target
⢠Does not require accuracy ⢠You must have someÂ
⢠Worry about geographic precision to be accurate
miss ⢠Worry about collateralÂ
damage
High precision, low accuracy Precise and accurate High accuracy, low precision
8. ⢠Distended rectum at timeÂ
of CT was independentlyÂ
associated withÂ
associated with
biochemical recurrence inÂ
prostate cancer and lowerÂ
rectal toxicity
t l t i it
⢠With precise treatment,Â
we need accurate deliveryy
11. Why do margins matter?
Why do margins matter?
⢠Volume = 4/3Ďr3
Volume = 4/3Ďr
⢠Small margin reduction (5mm) decreasesÂ
the volume of an orange by 1/2
the volume of an orange by 1/2
12. Big Picture Concepts
Big Picture Concepts
⢠How can we deal with our margins?
â GTV/CTV: limited by our tumor detection
⢠Relies on clinical judgment and our radiologyÂ
colleagues
â We can do something about PTV!!!
IMPROVING PATIENT SETUP AND TX DELIVERY
- Skin marks/weekly port films
- Daily setup to bony anatomy
- Immobilization and gating
- Planar and volumetric image guidance
and/or fiducials
- Stereotactic delivery
13. In Search of Guidance
In Search of Guidance
⢠Effectively identify tumor and normal tissue
Effectively identify tumor and normal tissue
⢠Accurately align patient and precisely treat
â Sh ld h l
Should help with interâfraction motion
i hi f i i
⢠What about intraâfraction motion?
â Three general approaches:
⢠Enlarge PTV margin
⢠Prevent motion possible in some instances butÂ
not particularly comfortable
⢠Track motion
Track motion
14. Definitions
⢠Image guided radiation therapy (IGRT)
Image guided radiation therapy (IGRT).  Â
Two parts:
â Use of modern imaging techniques for defining
Use of modern imaging techniques for definingÂ
tumor and normal structures
â Use of modern imaging techniques to accurately
Use of modern imaging techniques to accuratelyÂ
and precisely deliver treatment
15. Broad Definition 6 D s of IGRT
Broad Definition â 6 Dâs of IGRT
⢠Detection and diagnosis
Detection and diagnosis
⢠Determining biological attributes
⢠Delineation of target and organs at risk
l f d k
⢠Dose distribution design
⢠Dose delivery assurance
⢠Deciphering treatment response throughÂ
Deciphering treatment response through
imaging
Greco, Carlo and Clifton Ling, C.(2008)'Broadening the scope of Image-Guided Radiotherapy (IGRT)',Acta
Oncologica,47:7,1193 â 1200
44. Immobilization
⢠Abdominal Compression
â Hof et al 2003:
Hof et al. 2003:
⢠Lung tumor motion:Â
â cc 5.1 +/â 2.4 mm
â Lat 2.6 +/â 1.4
â APÂ 3.1Â +/â1.5mm
⢠B d Fi
Body Fix
⢠Hexapod
www.elekta.com
45. Breathing Control
Breathing Control
⢠Breath Hold (Can be coupled with RPM)
â Onishi et al 2003
Onishi et al. 2003
⢠Lung tumor motion is 2â3 mm
⢠Gives reduced lung density because is
Gives reduced lung density because isÂ
endâinspiration
⢠Active Breathing Coordinatorâ˘Â
(Elekta)
â 15â30 sec breath hold
â M
Many studies show excellent  limitationÂ
t di h ll t li it ti
of tumor motion 1â2 mm
⢠High Frequency Jet Ventilation (HFJV)
High Frequency Jet Ventilation (HFJV)
(Acutronic Medical Systems)
51. Precise Delivery (IMRT)
Precise Delivery (IMRT)
⢠Ix and Trilogy (Varian)
and Trilogy (Varian)
â RapidArcâ˘
⢠Txâ˘Â (NovalisâVarian)
T ⢠(N li V i )
⢠TomotherapyÂŽÂ (HIâART)
⢠SynergyŽ (Elekta)
⢠Artisteâ˘Â (Siemens)
t ste (S e e s)
⢠Compensator based methods
⢠Addâon serial tomotherapy (Best Nomos)
Add on serial tomotherap (Best Nomos)
68. UAB Motion Management Studies
UAB Motion Management Studies
⢠ASTRO 2009
â E l E
Early Experience with the Use of Gold Fiducial Markers inÂ
i ih h U f G ld Fid i l M k i
IGRT of Pancreatic Cancers
⢠Rojymon Jacob et al.
⢠Conclusion: Additional margins of 0.4 cm(AP), 1.0 cm (SI), and 0.8Â
cm (Lat) are needed around the target for IMRT if skeletalÂ
registration is performed without fiducials
â Respiratory Motion of Different Thoracic RegionsÂ
Determined by Prospective Gated CT for Treatment Planning
⢠S i Sh
Sui Shen et al.
t l
⢠95% Range of Motion of thoracic tumors/nodes were determinedÂ
on 4D datasets from 90 patients with most significant motion seenÂ
in inferior, anterior and lateral lung regions
i i f i t i dl t ll i
75. In Vivo Dosimetry at UAB?
In Vivo Dosimetry at UAB?
⢠15â20 Gy x 3 in 40 patients
15 20 Gy x 3 in 40 patients
⢠~75% treated for secondary metastases
⢠4D CT simulation with abdominalÂ
l h bd l
compression
â PTV = gated ITV plus 5 mm
â < 5 mm tumor motion then no gating
â Gated KV or CBCT image guidance
â Most commonly 7â13 beams
Courtesy of John Fiveash and Chris Dobelbower
76. 18 Gy
18 Gy
Courtesy of John Fiveash and Chris Dobelbower
77. Acknowledgements
⢠UAB â John Fiveash
â Janice Carlisle â Chris Dobelbower
â Heather Smith â Sui Shen
h
â Mark Hyatt ⢠Vanderbilt
â Rojymon Jacob
R j J b â J i C
Jostin Crass
â John Stewart