title: Single-dose compared with fractionated-dose radiation of the OM431 choroidal melanoma cell line.
abstract: OBJECTIVE
  To compare single-dose and fractionated-dose radiotherapeutic effects on choroidal melanoma cells.
  
  
  METHODS
  We determined the effects of gamma radiation on OM431 cell survival by exposing cells to either a single 9-Gy dose or two 4.5-Gy fractionated doses at intervals of 20 minutes to eight hours. The effects of single dosing and fractionated dosing at six hours were compared at doses of 2 to 12 Gy.
  
  
  RESULTS
  Tumor cell repair was most rapid during the first two hours. Maximum repair had occurred by six hours after radiation. Cell survival curves showed doses greater than 3 Gy of single-dose gamma radiation resulted in a greater number of cells killed than did equivalent fractionated doses.
  
  
  CONCLUSIONS
  Ocular melanoma in vitro is relatively radioresistant to low-dose fractionated radiotherapy. High single-dose radiotherapy would be more effective but would also result in more damage to normal tissue unless more focused modalities of radiotherapy are used.
authors.affiliation: Department of Ophthalmology, University of California Los Angeles, School of Medicine, USA.
authors.forename: S
authors.initials: S
authors.lastname: Logani
authors.forename: A S
authors.initials: AS
authors.lastname: Cho
authors.forename: B H
authors.initials: BH
authors.lastname: Ali
authors.forename: H R
authors.initials: HR
authors.lastname: Withers
authors.forename: W H
authors.initials: WH
authors.lastname: McBride
authors.forename: K L
authors.initials: KL
authors.lastname: Kozlov
authors.forename: M O
authors.initials: MO
authors.lastname: Hall
authors.forename: D A
authors.initials: DA
authors.lastname: Lee
authors.forename: B R
authors.initials: BR
authors.lastname: Straatsma
mesh_terms: D002470:Cell Survival / Q000528:radiation effects; D002830:Choroid Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D003037:Cobalt Radioisotopes; D004261:DNA Replication / Q000528:radiation effects; D004273:DNA, Neoplasm / Q000528:radiation effects; D005720:Gamma Rays; D006801:Humans; D008545:Melanoma / Q000473:pathology / Q000532:radiotherapy*; D011829:Radiation Dosage; D014407:Tumor Cells, Cultured
chemical_list: D003037:Cobalt Radioisotopes; D004273:DNA, Neoplasm