Halogenated pyrimidines as radiosensitizers for high-LET radiation.
The incorporation of iododeoxyuridine (IdUrd) into Chinese hamster cells was examined as a possible radiosensitizer for fission spectrum neutrons. Dose-response curves comparing both X rays and neutrons in the same cell line with the same IdUrd replacement showed a similar radiation enhancement for IdUrd incorporation. Enhancement ratios at the 1% survival level were 1.8 for X rays and 1.5 for fission spectrum neutrons. While the mechanism of this enhancement in the response for fission neutron radiation is unclear, these positive data should support further exploration to determine if halogenated pyrimidine incorporation results in sensitization for neutron energies employed in therapy.
Atcher
R W
RW
Radiation Oncology Branch, National Cancer Institute, Bethesda, Maryland 20892.
Russo
A
A
DeGraff
W G
WG
Moore
M
M
Grdina
D J
DJ
Mitchell
J B
JB
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D007065:Idoxuridine / Q000494:pharmacology*; D009502:Neutrons; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*
D011838:Radiation-Sensitizing Agents; D007065:Idoxuridine