Low-dose-rate radiation sensitivity of a human hepatoma cell line

A human hepatoma cell line, HepG2, is being used in a study of the radiobiologic factors that determine the effectiveness of radiolabeled immunoglobulin therapy of primary hepatoma. Growth inhibition by continuous low-dose-rate radiation occurs at lower dose rates for HepG2 than for most other cell lines studied. Based on survival curves following acute radiation, HepG2 appears to have less sublethal damage repair than most human tumors. Prior treatment with acute radiation did not sensitize HepG2 to either growth inhibition or cell killing by low-dose-rate radiation.