title: Effects of split-dose irradiation on survival and oncogenic transformation induced by 31 MeV protons in C3H10T1/2 cells.
abstract: Survival and oncogenic transformation were studied in C3H10T1/2 cells exposed to 31 MeV protons. Total doses of 0.5, 1 and 7 Gy were delivered as single and two equal fractions with various time intervals up to 10 h between doses. With split doses as compared with single doses to a total dose of 7 Gy, survival increased by a factor of 2.5 +/- 0.2, whereas the frequency of transformation per surviving cell declined by a factor of 3.1 +/- 0.5. Maximal split-dose recovery occurred within the first 5 h for both endpoints. Further, the transformation frequency decreased by factors of 3.1 +/- 0.6 and 1.5 +/- 0.3 respectively for total doses of 0.5 and 1.0 Gy split into two equal fractions. The data for 1 and 7 Gy are compatible with data in the literature for other low LET radiations.
authors.affiliation: Dipartimento di Fisica dell'Università di Milano.
authors.forename: D
authors.initials: D
authors.lastname: Bettega
authors.forename: P
authors.initials: P
authors.lastname: Calzolari
authors.forename: L T
authors.initials: LT
authors.lastname: Lombardi
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects*; D002471:Cell Transformation, Neoplastic / Q000528:radiation effects*; D051379:Mice; D011522:Protons; D011829:Radiation Dosage
chemical_list: D011522:Protons