TY - JOUR
T1 - Phosphorus-implanted glass for radiotherapy
T2 - Effect of implantation energy
AU - Kawashita, Masakazu
AU - Miyaji, Fumiaki
AU - Kokubo, Tadashi
AU - Takaoka, Gikan H.
AU - Yamada, Isao
AU - Suzuki, Yasuo
AU - Kajiyama, Kenji
PY - 1999
Y1 - 1999
N2 - A chemically durable glass that contains a large amount of phosphorus is useful for in situ irradiation of cancers. It can be activated to be a β-emitter with a half-life of 14.3 d by using neutron bombardment. Microspheres of the activated glass that are injected to tumors can irradiate the tumors directly with β-rays without irradiating neighboring normal tissues. In the present study, P+ ions in various doses have been implanted into a pure silica glass in a plate form at 200 keV. Almost all the implanted phosphorus is present in the inner region of the glass rather than in the surface region, taking the form of phosphorus colloids for all the doses in the range of 5×1016-1×1018 cm-2. A large number of amorphous phosphorus colloid particles with diameters of 10-150 nm are formed in the silica glass that has been implanted with a dose of 1×1018 cm-2; these colloid particles are distributed widely in a layer that is centered at a depth of 200-250 nm. All the investigated glasses hardly release any phosphorus and silicon into water at a temperature of 95 °C, even after 7 d. A silica glass that has been implanted with P+ ions at 200 keV with a dose of 1×1018 cm-2 is believed to be useful as a radiotherapy glass with sufficient phosphorus content and high chemical durability.
AB - A chemically durable glass that contains a large amount of phosphorus is useful for in situ irradiation of cancers. It can be activated to be a β-emitter with a half-life of 14.3 d by using neutron bombardment. Microspheres of the activated glass that are injected to tumors can irradiate the tumors directly with β-rays without irradiating neighboring normal tissues. In the present study, P+ ions in various doses have been implanted into a pure silica glass in a plate form at 200 keV. Almost all the implanted phosphorus is present in the inner region of the glass rather than in the surface region, taking the form of phosphorus colloids for all the doses in the range of 5×1016-1×1018 cm-2. A large number of amorphous phosphorus colloid particles with diameters of 10-150 nm are formed in the silica glass that has been implanted with a dose of 1×1018 cm-2; these colloid particles are distributed widely in a layer that is centered at a depth of 200-250 nm. All the investigated glasses hardly release any phosphorus and silicon into water at a temperature of 95 °C, even after 7 d. A silica glass that has been implanted with P+ ions at 200 keV with a dose of 1×1018 cm-2 is believed to be useful as a radiotherapy glass with sufficient phosphorus content and high chemical durability.
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U2 - 10.1111/j.1151-2916.1999.tb01817.x
DO - 10.1111/j.1151-2916.1999.tb01817.x
M3 - Article
AN - SCOPUS:0032686777
VL - 82
SP - 683
EP - 688
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
SN - 0002-7820
IS - 3
ER -