| Abstract
Purpose: Cancer radionuclide therapy is an effective, beneficial, and crucial method of cancer treatment that uses
unsealed radioactivated radionuclides sources that are attached to a targeting vector to deliver therapeutic radiation doses
from the ionizing radiation source to specific disease sites either for curative intent or for disease control and palliation
for the patient pain decreasing. For this aim, Monte Carlo N–Particle 5 (MCNP5) MC computational code was
employed for simulations and calculations as well as radiation transport.
Materials and Methods: 50nm
90
Y radionuclide nanosphere was modelled coated by a 10nm coating layer with some
non-toxic high and low Z materials. Physical interactions, such as β-ray and the simulated coating materials were
studied and radiological parameters were scored by the used MC code. Attenuation of β-ray, and production of the
bremsstrahlung X-ray photons and other phenomena were simulated by the code and analyzed. MC code estimated
the effect of the simulated coating materials, such as Gold, Platinum, Gaddolonium, Silver, and Epoxy-Resin on the
radiation characteristics around the modelled nano-radionuclide per 2nm from the radiation source surface to 1µm
distance. Produced bremsstrahlung X-ray by the source coating material and tissue atoms, emitted β-particle number,
flux over the surfaces (per 2nm), radiation fluence of photon and β- ray, deposited energy per gr of the cell medium,
and average dose to the cells around the 500nm and 1µm distance from the radionuclide source surface also was
derived.
Results: Our results showed that coating the radionuclide with the materials especially high Z (Gold and Platinum)
materials may produce a dual emitter radiation source, X-ray photon and β- ray and is capable of killing the cancer
cells more than the source with not-coated source.
Conclusion: Our conclusion was that coating the β- ray emitter radionuclides, especially high-energy β- ray, enhances
its therapeutical capability with X-ray and β- ray emission. The studied coated sources in our study were performed as
a dual radiation source; produced X-ray and β-ray, which increases the therapeutic efficiency of the source. |