TOMSK,
Mar 19 – RIA Tomsk. Tomsk Polytechnic University (TPU) scientists constructed easy and safe
in production device – collimator protecting healthy tissue during radiation
therapy. Analogs are usually made of metals in special labs, Tomsk residents
used 3D-printing for the first time, teacher of School of the Nuclear Science
& Engineering TPU Yury Cherepennikov reported.
Ideal form for a bunch
"That during radiation therapy healthy tissue haven't suffered, it is
necessary to irradiate strictly certain area. The best way for this purpose is
when an electron beam initially has a given form coinciding with tumor borders,
but not standard square or round", – Cherepennikov, PhD in Engineering
Sciences, senior teacher of Division of Nuclear Fuel Cycle School of the
Nuclear Science & Engineer of TPU explains.
Special devices – collimators are used for giving a form to a bunch. Roughly speaking,
it is "narrowers", windows for electrons which are made individually
on the basis of the patient's tomography, under a concrete form of a tumor, and
then are imposed on the radiator.
"Around the world collimators are made of mix of metals, the material is
heavier, the more effectively it absorbs radiation. Alloy of bismuth, lead, tin
and cadmium is most often used. But it is toxic in liquid state, and the
hospital has to equip the certain room with a powerful extract for work with
it. And qualified personnel is necessary for it", – Cherepennikov tells.
Scientists of Tomsk Polytechnic University were first-ever who suggested to
manufacture collimators by means of devices of fast prototyping – 3D-printers.
Shock-resistant polystyrene – usual, widespread plastic is used as material.
"The modern 3D-printer with very good characteristics will cost tens times
cheaper, than melting installation and the organization of conditions for its
work", – Cherepennikov emphasizes.
© РИА Томск. Елена Тайлашева
On the right – the metal collimator manufactured for the real patient of the Moscow City Oncology Hospital No 62. At the left – plastic, offered by collective of the scientists of TPU.
Plastic isn't worse than metal
Residents of Tomsk made a series of the experiments proving that plastic is so
effective, as well as metal. They took place in the Cancer Research
Institute of the Tomsk NRMC, in the Moscow City Oncology Hospital No 62, in the
University Medical Center Hamburg-Eppendorf.
"We measured deep distribution of a dose in plastic and calculated exact
value of thickness, necessary to absorb electron beams with this or that energy
on different installations for electronic radiation", – Sergey Stuchebrov,
PhD of Physico-Mathematical Sciences, the associate professor of Research
School of High Energy Physics of TPU tells.
© РИА Томск. Елена Тайлашева
"Russia, unfortunately, has strongly lagged behind in development of devices for treatment of oncological diseases – it is very difficult and expensive. But we can propose breakthrough solutions for operation of already existing installations", – Stuchebrov says.
Researches in humans weren't conducted yet. Now the collective prepares for
tests together with the Tomsk Cancer Research Institute.
"Introduction of any scientific development, including our collimators, in
clinical practice is very labor-intensive and long process. However, we expect
that existence in the territory of the Tomsk region of the specialized
scientific research medical center where new approaches to treatment are
developed will accelerate it", – one more member of the research team
Irina Miloychikova, medical physicist of the Division of Radiotheraphy of the
Cancer Research Institute of the Tomsk NRMC and the assistant of the Division
of Nuclear Fuel Cycle School of the Nuclear Science & Engineer of TPU says.
She specifies that their development is suitable for installations with an
electronic radiation which are used, generally for treatment of close located
new growths.
In the long term the team intends to work on the collimator for accelerators
with a gamma radiation, the oncological diseases, most widespread in treatment.
To stop a gamma bunch, it will be necessary to add special impurity to plastic.
Which – it should be found out.