Longitudinal measurement of subcutaneous and intratibial human prostate cancer xenograft growth and response to ionizing radiation by plasma Alu and LINE-1 ctDNA: A comparison to standard methods.

Real-time qPCR of circulating human Alu and LINE-1 DNA provides an accurate measurement of subcutaneous and intratibial xenograft burden that is comparable with conventional bioluminescence imaging and slide caliper measurement. Transient differences in measurements were observed following tumor-targeted IR, but overall all measurements mirrored tumor growth and response.