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SU‐G‐TeP3‐05: In Vitro Demonstration of Endothelial Dose Enhancement Due to Gold Nanoparticles During Low‐Voltage Radiotherapy
Author(s) -
YasminKarim S,
Moreau M,
Kumar R,
Makrigiorgos GM,
Hanlon J,
Arnoldussen M,
Hempstead J,
Celli J,
Ngwa W
Publication year - 2016
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4957085
Subject(s) - radiation therapy , clonogenic assay , medicine , nuclear medicine , radiosurgery , cancer research , irradiation , in vitro , umbilical vein , chemistry , biochemistry , physics , nuclear physics
Purpose: Oraya Therapy uses low‐voltage, stereotactic, highly targeted X‐rays for the treatment of wet age‐related macular degeneration (AMD) — offering a new option for patients worldwide. Neovascular endothelial cells play a crucial role in the pathogenesis of this disease. This in‐vitro study investigates the potential of gold nanoparticles (GNP) to enhance endothelial cell damage during low‐voltage radiotherapy towards potential applications in the treatment of wet‐AMD. Methods: Primary human umbilical cord vein endothelium cells (HUVEC) were treated with 1.4 nm sized GNPs for 24 hrs and then irradiated with variable X‐ray doses using an Oraya therapy system (100 kVp) or a Small Animal Radiation and Research platform (SARRP) at other beam qualities (up to 220 kVp). Radio‐sensitization was assessed by clonogenic assays. Variable concentrations of GNPs (0.05 mg/ml, 0.1 mg/ml, 0.25 mg/ml, 0.5 mg/ml, and 1 mg/ml) where employed. The dose enhancement factor (DEF) was calculated as the ratio of radiation doses required to give the same biological effect (survival factor, SF) with and without GNPs. Results: Preliminary results show DEFs of up to 2.62 for the different combinations of x‐ray doses and GNP concentrations and beam qualities. In general the DEF increased with increase in GNP concentration. However, for high doses the effect of GNP becomes less apparent likely due to already high cell kill by the radiation alone. Conclusion: The findings suggest that targeted GNPs can play a significant synergistic role in enhancing stereotactic radiosurgery for wet AMD. The results also provide impetus for ongoing studies to find the optimal synergy between the doses or beam energies and GNPs concentration. This will benefit in‐vivo studies towards development of nanoparticle‐aided radiotherapy for treatment of wet‐AMD and potentially ocular cancers.