Monitoring response to radiotherapy in human squamous cell cancer bearing nude mice: comparison of 2'-deoxy-2'-[18F]fluoro-D-glucose (FDG) and 3'-[18F]fluoro-3'-deoxythymidine (FLT).

Objective: The uptake of 3'-[18F]fluoro-3'-deoxythymidine (FLT), a proliferation marker, was measured before and during fractionated radiotherapy to evaluate the potential of FLT-positron emission tomography (PET) imaging as an indicator of tumor response compared to 2'-deoxy-2'-[18F]fluoro-D-glucose (FDG).

Materials And Methods: Nude mice bearing established human head and neck xenografts (HNX-OE; nu/nu mice) were locally irradiated (three fractions/week; 22 Gy) using a 150-kVp unit. Multiple FDG- and FLT-PET scans were acquired during treatment.