Radiosensitization of Prostate Cancers In Vitro and In Vivo to Erbium-filtered Orthovoltage X-rays Using Actively Targeted Gold Nanoparticles
Theoretical
investigations suggest that gold nanoparticle (GNP)-mediated radiation dose
enhancement and radiosensitization can be maximized when photons interact with
gold, predominantly via photoelectric absorption. This makes ytterbium
(Yb)-169, which emits photons with an average energy of 93 keV (just above the K-edge of gold), an ideal radioisotope for such
purposes. This investigation tests the feasibility of tumor-specific prostate
brachytherapy achievable with Yb-169 and actively targeted GNPs, using an
external beam surrogate of Yb-169 created from an exotic filter material -
erbium (Er) and a standard copper-filtered 250 kVp beam. The current in vitro study shows that treatment of prostate
cancer cells with goserelin-conjugated gold nanorods (gGNRs) promotes
gonadotropin releasing hormone receptor-mediated internalization and enhances
radiosensitivity to both Er-filtered and standard 250 kVp beams, 14 and 10%, respectively. While the degree of GNP-mediated
radiosensitization as seen from the in vitro study may be considered moderate,
the current in vivo study shows that gGNR treatment plus Er-filtered x-ray
irradiation is considerably more effective than radiation treatment alone (p < 0.0005), resulting
in a striking reduction in tumor volume (50% smaller) 2 months following
treatment. Overall, the current results provide strong evidence for the
feasibility of tumor-specific prostate brachytherapy with Yb-169 and gGNRs.
You can find the full text at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5741750/
Source: Scientific Report