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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2011-7-20
pubmed:abstractText
Gold nanoparticle (AuNP) radiosensitization represents a novel approach to enhance the effectiveness of ionizing radiation. Its efficiency varies widely with photon source energy and AuNP size, concentration, and intracellular localization. In this Monte Carlo study we explored the effects of those parameters to define the optimal clinical use of AuNPs. Photon sources included (103)Pd and (125)I brachytherapy seeds; (169)Yb, (192)Ir high dose rate sources, and external beam sources 300 kVp and 6 MV. AuNP sizes were 1.9, 5, 30, and 100 nm. We observed a 10(3) increase in the rate of photoelectric absorption using (125)I compared to 6 MV. For a (125)I source, to double the dose requires concentrations of 5.33-6.26 mg g(-1) of Au or 7.10 × 10(4) 30 nm AuNPs per tumor cell. For 6 MV, concentrations of 1560-1760 mg g(-1) or 2.17 × 10(7) 30 nm AuNPs per cell are needed, which is not clinically achievable. Examining the proportion of energy transferred to escaping particles or internally absorbed in the nanoparticle suggests two clinical strategies: the first uses photon energies below the k-edge and takes advantage of the extremely localized Auger cascade. It requires small AuNPs conjugated to tumor targeted moieties and nuclear localizing sequences. The second, using photon sources above the k-edge, requires a higher gold concentration in the tumor region. In this approach, energy deposited by photoelectrons is the main contribution to radiosensitization; AuNP size and cellular localization are less relevant.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1361-6560
pubmed:author
pubmed:issnType
Electronic
pubmed:day
7
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4631-47
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Implications on clinical scenario of gold nanoparticle radiosensitization in regards to photon energy, nanoparticle size, concentration and location.
pubmed:affiliation
Department of Medical Biophysics, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario M4N3M5, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't