RecruitingDevice study3'-Deoxy-3'-[18F] Fluorothymidine PET Imaging in Patients With CancerRATIONALE: Diagnostic procedures, such as 3'-deoxy-3'-\[18F\] fluorothymidine (FLT) PET imaging, may help find and diagnose cancer. It may also help doctors predict a patient's response to treatment and help plan the best treatment. PURPOSE: This phase I trial is studying FLT PET imaging in patients with cancer.