The II th Symposium on Accelerator Science and Technology, Harima Science Garden City, I997

Hyogo Hadron Therapy Center
Takashi AKAGI, Morimasa HASHIMOTO, Yoshio HISHIKAWA, Akio H][GASHI,Hiroshi KARASHIMA, Kyoichi ISHIDA, Akifumi ITANO, Michhisa KATO and Yoshihisa NAKAYAMAPublic Health Department , Hyogo Prefectural Government
Kobe, Hyogo, 650 JAPANMasahiro ENDO, Yasuo HIRAO, Tatsuaki KANAI, Kiyomitsu KAWACHI,Koji NODA, Masami TORIKOSH I and Satoru YAMADA
National Institute of Radiological Sciences
Inage, Chiba, 263, JAPANTable 1Clinical requirement

AbstractHyogo Prefectural Government has decided andstarted construction of Hyogo Hadron Therapy Center inHarima Science Garden City, where is about 75km awayfrom Kobe City to the north-west. The center has injector, synchrotron, high energy beam transport systemand treatment system. The accelerator complex can accelerate proton, helium, and carbon. The energy ranges
are 70-230 MeV ju for proton and helium, and 70-320
MeV /u for the carbon. The beam intensity is required
to satisfy the dose rate of 5Gy/min. for treatment volume of 15cmq) field size and fully extended spread out
Braggpeak( SOBP). The beam transport system consistsof three horizontal ports, one vertical ports, and one 45°
oblique port for proton, helium and carbon beam, twoisocentric gantry ports only for proton beam. A hospital within 50 beds is constructed with the site. Patient
treatment will be started in the year 2001.
1 Introductio n

Since the proton beam has a good dose distribution
due to so called Bragg peak comparing to X-ray, radiotherapy with proton has been trend in the present days.
The Bragg peak .can be extended three-dimensionallyas to fit to tumor size by treatment system devices.
Heavy ions like carbon have more excellent distributionof the dose than proton due to the small multiple scattering and the small beam straggling. They have also
higher radio-biological effectiveness than X-ray and proton. Clinical trials with the carbon beam have been successfully progressing at Heavy Ion Medical Accelerator
in Chiba (HIMAC) in the National Institute of Radiological Sciences (NIRS) [1] from June in 1994.
Hyogo Prefectural Government has decided construction of a Hadron Therapy Center referring to theresults of HIMAC [2]. The beam particles are proton,helium and carbon. Accelerator and treatment system
are designed to satisfy the clinical requirement shown in
Table 1. The beam should be well controlled with anaccuracy. The intensity of the beam should be enoughto finish the irradiation within a few minutes. Furthermore, the center aims to have treatment of 1200 patients
per year. In order to achieve the aim, the stable operation and reproducibility are required to the accelerator
and the beam transport. The operation is automated as
possible to reduce man power and running cost.

Particles
Dose Rate
Beam Range
Field sizeField homogeneity
Displacement of beam

Proton, Helium, Carbon
5Gy/min for maximum
treatment volume of15cmq)xfull SOBP
4-30cm for p & He
1.3-20cm for C
15cmx15cm±2%± 2mm (from isocenter)2 Accelerato r

The injector consists of two 10GHz ECR ion sources
with 35keV ju output energy, 1 MeV /u RFQ linac,Alvarez linac and debuncher. The linaces accelerates the hydrogen molecule, helium(Q/ A=l/2) and carbon(Q/A=l /3) up to 5 MeVju. A stripper located_downstream of the linaces cascade makes the particles
fully stripped. The operation RF frequency of the linac
is 200 MHz. The debunGher then reduces a momentum
spread of the beam. The synchrotron ring is a separatedfunction type with a strong FODO focusing structure
and its super periodicity is 6. The maximum rigidity ofthe ring is 5.58Tm. The beam is extracted by the thirdorder resonance scheme and sent to the beam transportsystem. Fig. 1 shows a layout of the accelerator complex and the beam transport system. We summarize thebeam specifications of the accelerator in Table 2, which
satisfy the clinical requirements
Table 2Beam_ specifications
Energy Range
Beam Intensity
Beam spill length
Beam repetition rate

70-230 MeV/u for p & He
70-320 MeV ju for C
7.2 x 1010 pps for p
1.8 x 1010 pps for He
1.2 x 109 pps for C
400ms
1Hz for p
0.5Hz for He & C

We have four fixed beam transports for all particles
and two gantry ports for proton which are identical. The
fixed beam ports consist of two horizontal ports, a vertical and an 45° oblique port. Another beam port is constructed for physical and/or biological experiments. All
the magnets are made from laminated steel for the beam

-116-The 11th Symposium on Accelerator Science and Technology, Harima Science Garden City, 1997~Bending Magnet

RFQLinac

ECR Ion Sources
Fig. 1 Layout of the accelerator complex and treatment rooms
to have good reproducibility and energy variability. The
magnet rigidity is 1.231 to 2.332 Tm for the gantry port
corresponding to the proton beam energy range, 70 to230 MeV ju, and 1.231 to 5.578 Tm for the fixed port corresponding to the carbon beam energy range, 70 to 320
MeV ju. The stability and reproducibility of the beam
spot position is within ±2mmat the isocenter. The timeto switch beam condition to another one should be taken
short to treat many patients. The switching is done byinitializing the corresponding magnets on the accelerator complex and changing the excitation pattern (andthe ion source for switching particles). The sufficientmachine study and automation of the switching operation make the switching time short. The expected times
to switch beam condition are summarized in Table3.

port is shown in Fig.3. The distance between the last
bending magnet and the isocenter is 9m for the fixed
ports (8m for the fixed port with the small irradiation
field) and 3.4m for the gantry port. The gantry port isshorter than the fixed port to make its size compact. Inorder to reduce the multiple scattering on the fixed port,
the beam line is evacuated until the end of the neutron
shatter. The vacuum is 5 x w- 7 Torr in the average.
Nuetron
ShatterTable 3
Expected time to switch beam to another condition.
Treatment room
EnergyParticles

Range
Shifter

Bed

1 min.
15 min.
30 min.

magnets

3 Treatment System

Colimator
Ridge Filter
Fig. 2 Schematic elevation view of the treatment system on the horizontal fixed port.

Treatment system devices are arranged at the end ofeach port to make an irradiation field. One horizontal
port has a large irradiation field (15cmx 15cm) and another horizontal port has a small irradiation field (5cm¢) aimed for radiosurgery. The horizontal fixed portwith the large field is shown in Fig.2, and the gantry

The system devices consist of two wobbler magnets,
scatterer, ridge filters, fast range shifter, and multi-leaf
collimator from the upstream as shown in Fig. 's 2 and 3.
The beam is extended in the lateral by combination of
the wobbler magnets and the scatterer. The range of thebeam is modulated by the ridge filters to make spread(x,y)-117-The 11th Symposium on Accelerator Science and Technology, Harima Science Garden City, 1997

Accelerator
Budget Accelerators
beam delivery & Building &year
insirumentation conventional plan

Hospital

1995 Basic design- - - Detrailed- - - - -design---- - - - - - - - ----- - - - - - Basic design
Design

1996

Basic design--- --- -- ------------ ---------1997
Construction

Construction----- - - - - -------------------- Design

1998----- -- - - - - - - - - - - - - - - - - - - - - - Construction1999- - - - !n~taJll!tiQn- - - .~O_ffi!ll~Sipl!in,g _ - - - - - - - 2000---

~o_m!Jl~Si,SJJ!in_g _2001 Routine beam
operation<;o!fi!ll~Si~njng _- - - - - - - - Patient
treatment

Fig. 4 Construction time scheduleFig. 3

References

out Bragg peak(SOBP). The multi-leaf collimator consists of many narrow leaves of which width is expected tobe less than 6mm. It can make any shape by moving theleaves one by one to fit to target tumor. The fast range
shifters change the range to adjust the depth of the penetration in a very short time of 30cmfsec expected. The
beam range can be also changed by changing the beamenergy extracted from· the synchrotron pulse by pulse.
It makes a three-dimensional broad beam irradiation [3]possible. These energy modulation is also prepared fortreatment with voxel/raster scanning method in the future. The irradiation during treatment is synchronizedwith patient's breathing. A breathing signal of patientis taken, and the beam is gated by RF knock-out extraction method [4] during the signal below a threshold.

[1] H. Tujii, "Commencing heavy-ion clinical trial at HIMAC.", Proceedings of NIRS International Seminaron the Application of Heavy Ion Accelerator to Radiation Therapy of Cancer in connection with XXIPTCOG Meeting, Editor T. Kanai and E. Takada,NIRS, Chiba, Japan, November 1994, NIRS-M-103
and HIMAC-008.
[2] A. Itano et al., "Hyogo Hadrontherapy CenterProject.", Contribution paper for II Internal Symposium on Hadrontherapy, September 1996.
[3] Y. Futami et al., "Broad Beam There-dimensional
Irradiation System for Heavy-Ion Radiotherapy atHIMAC", to be published.
[4] K. Noda et al.,"Slow beam extraction by a transverse RF field with AM and FM.", Nucl. Instru. andMeth.,A374 (1996) 267-277.

4 Conclusion

The accelerators and treatment system has been designed as to satisfy the clinical requirement. The detaildesign is still in progress. The construction of the building will be started on October in 1997, this year, and becompleted in two years. The detail construction schedule
is summarized in Fig. 4. Patient treatment is expected
to be started in the year 2001.
Acknowledgment

We would like to thank members of committee of thetreatment system and committee of the accelerator for
their effort to design the center.

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