Medical Division consists of two doctors, one radiological technologist
and two medical physicists. At the division, we are working on clinical
studies and research for the advancement in proton cancer therapy (cancer
therapy by proton beam).*
* Proton cancer therapy:
Proton beam is a type of radiation created by accelerating a proton or
hydrogen nucleus to a high speed. It can concentrate its radiation dosage
to the cancer focus better than X ray which is mainly used in the conventional
radiotherapy. Proton cancer therapy, therefore, has fewer side-effects,
and it is expected to preserve functions and to maintain the QOL (quality
of life) after the therapy.
◆Present state of the clinical studies of proton cancer therapy
We started clinical studies of liver cancer in FY2003 in addition to the
past studies of prostate cancer.
The location of the tumor site of liver cancer changes by breathing. So
it is necessary to irradiate the tumor site with a proton beam accurately
by aiming at it using a breathing synchronization sensor.
We had treated thirty-five cases of prostate cancer, three cases of liver
cancer and one case of lung cancer by December 2006, and achieved positive
results without particular side-effects.
On the basis of these achievements in the clinical studies, “Fukui Proton
Cancer Therapy Center (tentative name)” is to be established in Fukui Prefectural
Hospital in FY2009.
Proton cancer therapy device
CT images of liver cancer
before treatment (left), after treatment (right)
◆Future efforts toward proton cancer therapy
We at WERC will continue working on the basic studies for proton therapy
to advance particle beam therapy. Now we are working on “genetic research
for proton beam effects”, “research for the advancement of therapy planning
system” and “development of a quality assurance technique for particle
radiotherapy.”
In the “genetic research for proton beam effects”, we aim at clarifying
the mechanism of proton beam effects on cells. Although the biological
effect of proton beam on cells is similar to that of X ray, its mechanism
is considered to differ. Thus we are searching for the mechanism through
genetic methods. It is expected to develop a more effective approach to
proton therapy by utilizing the difference in mechanism.
The “research for the advancement of therapy planning system” is to develop
a proton therapy planning system which can flexibly correspond to more
advanced irradiation methods. We have already succeeded in developing a
positioning support system for proton CT therapy, and an integrated proton
therapy information management system for managing the medical images and
the information of proton therapy planning. We expect that the therapy
planning system under development will also be utilized as a tool to verify
commercially produced systems.
In the “development of a quality assurance technique for particle radiotherapy”,
we are working at developing technique to assess the dose administered
for purposes other than the original intent by establishing a method for
assessing the dose outside the irradiation field caused by the secondary
particles and scattered radiations produced during proton therapy. We especially
focus on reducing the dose outside the irradiation field produced during
the irradiation field enlargement by measuring dose distribution under
water to control operation parameters of the irradiation field forming
apparatus. We are also developing techniques to confirm an irradiation
field efficiently which is important for the proton therapy quality assurance,
and have already applied a patent for the optical CT system.
Fukui Proton Cancer Therapy Center
(tentative name)
Other research themes
Biological effectiveness of proton beam
Irradiation field forming test for proton cancer therapy
