![Page 1: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/1.jpg)
Medical Linear Accelerators in Radiation Therapy
Haijun Song, Ph.D.
Dept. of Radiation OncologyDuke University Medical Center
![Page 2: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/2.jpg)
MV Linear Accelerator
![Page 3: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/3.jpg)
Anatomy of a Linac
![Page 4: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/4.jpg)
Anatomy of a Linac
![Page 5: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/5.jpg)
![Page 6: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/6.jpg)
Beam MofiersCone
MLC (Multi-Leaf Collimator)
![Page 7: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/7.jpg)
Radiosurgery with Linac
![Page 8: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/8.jpg)
MLC
![Page 9: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/9.jpg)
Conformal RT (3DCRT) &Intensity Modulation RT (IMRT)
![Page 10: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/10.jpg)
Conformal RT (3DCRT) &Intensity Modulation RT (IMRT)
![Page 11: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/11.jpg)
Dose Map delivered by IMRT
![Page 12: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/12.jpg)
Dose Map delivered by IMRT
![Page 13: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/13.jpg)
Dose Map delivered by IMRT
![Page 14: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/14.jpg)
Image Guided RT (IGRT)
![Page 15: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/15.jpg)
Respiratory Gating RT
![Page 16: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/16.jpg)
Tomotherapy and Robotic
![Page 17: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/17.jpg)
Difference among Radiation Sources
Factors affecting radio-bio response• Gamma vs. Electron
Among Gamma sources• Photon Energy Spectrum• Dose Distribution• Dose Rate
![Page 18: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/18.jpg)
Radioactive IsotopesExample: Cs-137
• single dominant energy, 0.66 MeV• Activity: 6000 Ci and 100 Ci, dual source• Dose rate range: 0.001 - 10 Gy/min
![Page 19: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/19.jpg)
Radioactive Isotopes
Example: Ir-192• Complex energy spectrum: 30 gammas and
40 x rays.• Dose rate, 0.01 - 5 Gy/min being used RT.
Ir-192 photon spectrum
0.0001
0.001
0.01
0.1
1
10
100
1000
0.001 0.01 0.1 1 10
E (MeV)
Perc
ent p
er d
ecay
![Page 20: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/20.jpg)
From kV to MV
Commonly: 50 – 300 kVPBeam Quality: HVL a few mm Al to Cu.Dose Rate: around Gy/min
![Page 21: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/21.jpg)
From kV to MV
Commonly: 6 MV -25 MVBeam quality: PDD10 in water, 67% and up.Dose Rate: around Gy/min
![Page 22: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/22.jpg)
X-Ray tube vs. Linac
![Page 23: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/23.jpg)
Acce. Tube: Travelling Wave
![Page 24: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/24.jpg)
X-Ray ProductionSide emission vs. straight through emmission
![Page 25: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/25.jpg)
![Page 26: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/26.jpg)
Photon energy spectrum from a 6 MV beam
Fl uence/ MeV/ I ndi cent el ect r on
0. 00E+00
2. 00E- 05
4. 00E- 05
6. 00E- 05
8. 00E- 05
1. 00E- 04
1. 20E- 04
1. 40E- 04
0 1 2 3 4 5 6
Fl uence/ MeV/ I ndi centel ect r on
![Page 27: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/27.jpg)
Depth Dose Curves
![Page 28: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/28.jpg)
Dose Distribution: One beam/parallel beams
![Page 29: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/29.jpg)
Dose Distribution: One beam/parallel beams
![Page 30: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/30.jpg)
MV photon and electron beams
![Page 31: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/31.jpg)
Depth Dose of e Beams
0 1 2 3 4 5 6 7 8 90
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
M e V1 81 51 21 086
Per
cent
Dep
th Io
niza
tion
D e p t h ( c m ) i n W a t e r
![Page 32: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/32.jpg)
Dose Measurement
Ion chamber and electrometerIn water for MV photon or electron beamsIn air for KV beamsTracable to NIST Co-60 standard beam
CowDQ
Qw NkMD 60
,*=
![Page 33: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/33.jpg)
Buildup region and skin sparingCompton e1 1 1 1
Compton e2 1 1 1
Compton e3 1 1
Compton e4 1
Depth in water
Total dose 1 2 3 3
![Page 34: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/34.jpg)
Treating Superficial targetsBolus: tissue equivalent, soft to conform to skin
0 1 2 3 40
20
40
60
80
100
S
B dmax
Per
cent
Dep
th D
ose
Depth in Water (cm)
![Page 35: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/35.jpg)
Dose Distribution: One beam/parallel beams
![Page 36: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/36.jpg)
Buildup region and skin sparingcontinued
Skin sparing also means a target at shallow depth will not get adequate dose.
For small animals, “sparing” of a couple of centimeter from skin may “spare” the whole animal.
What do we do when we need to treat superficial target?
![Page 37: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/37.jpg)
Bolus
![Page 38: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/38.jpg)
Treating Superficial targetsBolus: tissue equivalent, soft to conform to skin
0 1 2 3 40
20
40
60
80
100
S
B dmax
Per
cent
Dep
th D
ose
Depth in Water (cm)
bolus
![Page 39: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/39.jpg)
Treating Superficial targetsBolus: tissue equivalent, soft to conform to skin
0 1 2 3 40
20
40
60
80
100
S
B dmax
Per
cent
Dep
th D
ose
Depth in Water (cm)
bolus
![Page 40: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/40.jpg)
Treating Superficial targets
MeV range electron beams /w bolus
kV (suferfical units, orthovoltage units)
MV photon beam with bolus
How useful are MeV electron beams for small animal irradiations?
![Page 41: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/41.jpg)
What can Rad Onc Offer Rad Biology
All offered to human can be offered to other species.
Imaging: CT, MRI
Precise and conformal dose coverage: 3DCRT, IMRT, IGRT, Respiratory Gating, radiosurgery, electron irradiation.
Precision and conformality means sparing healthy tissue, too.
And More: Brachytherapy, hyperthermia, proton, neutron.
![Page 42: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/42.jpg)
Acce. Tube: Standing Wave
![Page 43: Medical Linear Accelerators in Radiation Therapy - RadCCORE · Medical Linear Accelerators in Radiation Therapy Haijun Song, Ph.D. Dept. of Radiation Oncology Duke University Medical](https://reader031.vdocuments.us/reader031/viewer/2022021916/5d01ce5588c993c2488b5cf9/html5/thumbnails/43.jpg)
Acce. Tube: Short Standing Wave