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Carbon ions have less multiple scattering than protons : higher lateral precision carbon beam proton beam. Depth in tissue. 12 cm. EPFL 4- 4.11.10 - U. Amaldi ...
ACCELERATORS AND MEDICAL PHYSICS

4 Ugo Amaldi University of Milano Bicocca and TERA Foundation

EPFL 4- 4.11.10 - U. Amaldi

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The distribution of the dose in hadrontherapy

EPFL 4- 4.11.10 - U. Amaldi

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The narrow peak has to be enlarged longitudinally linac cobalt 60

Longitudinally and transversally the carbon peak is 3 times narrower than the proton peak.

proton

tail

The widths are prop. to 1/√M

light ion (carbon)

Spread Out Bragg Peak SOBP

General laws: R = Ro (E/Eo)1.82 ΔR/R = 1.8 ΔE/ E

Distal fall-off Δd/d=1%

For Δd 20 keV/μm and RBE > 1.5 in the last 40 mm so that carbon can control radioresistant tumours i.e. tumours which need 2-3 times larger doses to be controlled with either X rays or protons - U. Amaldi

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„ The “effective dose” in Gye is defined as Gy x RBE At GSI the values of RBE are computed with X-ray cell survival data by using the Local Effect Model (LEM) by G. Kraft el al.

To obtain a „flat‟ dose in Gye the “physical dose” is not „flat‟

Spread Out Bragg Peak

GSI EPFL 4- 4.11.10 - U. Amaldi

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The GSI Local Effect Model (LEM)

Different for tumour and healthy tissues

Survival =

M. Scholz, GSI EPFL 4- 4.11.10 - U. Amaldi

RBE computed from Survivals 43

Elective indications of carbon ions calculated with LEM

YES

YES

NO

YES

M. Scholz, GSI EPFL 4- 4.11.10 - U. Amaldi

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Elective indications of carbon ions calculated with LEM

YES

YES

M. Scholz, GSI EPFL 4- 4.11.10 - U. Amaldi

NO

YES

About 80% of all solid tumours 45

Numbers of potential patients (*) X-ray therapy every 10 million inhabitants:

20'000 pts/year

12% of X-ray patients

2'400 pts/year

Protontherapy

Therapy with Carbon ions for radio-resistant tumour 3% of X-ray patients

TOTAL every 10 M

600 pts/year

about 3'000 pts/year

______ (*) Combining studies made in Austria, Germany, France and Italy in the framework of ENLIGHT - Coordinator: Manjit Dosanjh – Projects in FP7: ULICE, PARTNER, ENVISION , ENTERVISION for a total of 22 MEuro EPFL 4- 4.11.10 - U. Amaldi

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Results photons

Results carbon HIMAC-NIRS

Results carbon GSI

local control rate

30 – 50 %

65 %

70 %

Chondrosarcoma

local control rate

33 %

88 %

Nasopharynx carcinoma

5 year survival

40 -50 %

63 %

Glioblastoma

av. survival time

12 months

16 months

Choroid melanoma

local control rate

95 %

96 % (*)

Paranasal sinuses local control tumours rate

21 %

63 %

6.5 months

7.8 months

23 %

100 %

24-28 %

61 %

31 – 75 %

52 -83 %

Indication Chordoma

End point

Pancreatic carcinoma

av. survival time

Liver tumours

5 year survival

Salivary gland tumours

local control rate

Soft-tissue carcinoma

5 year survival

Similar to protons

89 %

Table by G. Kraft 2007 Results of carbon ions

77 %

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THE END

EPFL 4- 4.11.10 - U. Amaldi

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