Single-dose compared with fractionated-dose radiation of the OM431 choroidal melanoma cell line

Am J Ophthalmol. 1995 Oct;120(4):506-10. doi: 10.1016/s0002-9394(14)72665-0.


Purpose: 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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Survival / radiation effects
  • Choroid Neoplasms / pathology
  • Choroid Neoplasms / radiotherapy*
  • Cobalt Radioisotopes
  • DNA Replication / radiation effects
  • DNA, Neoplasm / radiation effects
  • Gamma Rays
  • Humans
  • Melanoma / pathology
  • Melanoma / radiotherapy*
  • Radiation Dosage
  • Tumor Cells, Cultured


  • Cobalt Radioisotopes
  • DNA, Neoplasm