Radiation sensitivity index

The radiation sensitivity index is a gene-expression–based model developed to estimate the intrinsic radiosensitivity of tumor cells. RSI was created by correlating cancer cell line survival after ionizing radiation with baseline gene-expression patterns, identifying a set of genes predictive of cellular response to radiation.
RSI has been evaluated across multiple cancer types and clinical cohorts, and serves as the genomic basis of the genomic adjusted radiation dose, a framework integrating radiosensitivity with the linear–quadratic model to estimate the biological effect of a given radiation dose.