Mitsubishi Electric Begins Testing New Proton Therapy Technology – May 15, 2013– Tokyo, Japan  (Techreleased) – Mitsubishi Electric Corporation announced today that it has completed the construction of a new proton therapy system for cancer treatment at its Energy Systems Center in Kobe, Hyogo Prefecture. The company has started testing of the new technology including a high dose-rate beam delivery system which reduces the irradiation time to one fourth of the current level.

New Proton Accelerator (Synchrotron)
New Proton Accelerator (Synchrotron)

Mitsubishi Electric plans to perform the quality verification testing of this new system in collaboration with clinical institutions, and also utilize the preferred status granted as a member of the Kansai Innovation Comprehensive Global Strategic Special Zone in order to obtain early approval as a medical device.


Beam Line for Testing
Beam Line for Testing

Key Technologies to be Tested

1) High dose-rate beam delivery system

The new beam delivery system is intended to increase the maximum dose rate from 5Gy/min to about 15 to 20Gy/min at all depths, reducing the time to irradiate a tumor by as much as a factor of four over the current level. The shorter irradiation time provides a more comfortable setting for the patient.
2) High-accuracy pencil beam scanning technology

The new system increases the scanning speed five fold from 20mm/ms to 100mm/ms. At the same time the spot size is reduced in half from 10mm to 5mm. This means that the proton beam can be delivered more accurately more efficiently to complicated tumor volumes.
3) Universal nozzle for efficient operation

The treatment system supports a new nozzle capable of both pencil beam scanning and broad beam treatment. In pencil beam scanning, a finely focused particle beam is magnetically scanned across the tumor, tracing out the three-dimensional tumor volume. In broad beam treatment, the particle beam is spread out to create a uniform field. Using collimators, the treatment field is cut out from this uniform field according to the tumor shape. The nozzle is capable of quickly switching between the two modes of treatment.

Accelerator Test Facility at the Energy Systems Center, Kobe

Evaluation of new technologies
Perform tests according to customer requests from existing or planned facilities
Showcase the new treatment room designs
Particle Type Proton
Accelerator Type Newly developed synchrotron with variable energy capable of providing high beam-quality for pencil beam scanning, at all treatment depths.
Maximum Energy 235 MeV

Mitsubishi Electric has 50 years of experience and expertise in the fields of radiation therapy and accelerator systems, which the company combined to develop the particle therapy system. In 2002, Mitsubishi Electric obtained approval from the Ministry of Health, Labour and Welfare in Japan to manufacture and sell the proton therapy systems. In 2005, the company became the first manufacturer in the world to obtain approval for the carbon/proton-type therapy systems. In March 2010, approval was obtained for the “Compact Carbon-Type Particle Therapy System,” which was developed on the basis of the research work led by the National Institute of Radiological Sciences. To date, the above three types of systems have been installed at a total of eight facilities in Japan.

Mitsubishi Electric will continue to develop new technologies for the advancement of particle therapy, and in collaboration with clinical institutions, provide treatment systems that are safe and easy to use.

Facility Prefecture Year Ion Species
National Institute of Radiological Sciences Chiba 1994 proton
Hyogo Ion Beam Medical Center Hyogo 2003 proton/carbon
Shizuoka Cancer Center Shizuoka 2003 proton
Southern TOHOKU Proton Therapy Center Fukushima 2008 proton
Gunma University Heavy Ion Medical Center Gunma 2010 carbon
Fukui Prefectural Hospital Proton Beam Cancer Treatment Center Fukui 2011 proton
Medipolis Medical Research Institute Kagoshima 2011 proton
SAGA Heavy Ion Medical Accelerator in Tosu Saga 2013 carbon