We developed a technology called PlatinDx that, based upon preclinical data, can potentially identify chemoresistance in lung and bladder cancer patients before they receive carboplatin therapy. PlatinDx utilizes tracing of subtherapeutic """"""""microdoses"""""""" of 14C-labeled carboplatin with accelerator mass spectrometry (AMS), which has attomole (10-18 mole) sensitivity for 14C. We hypothesize that DNA damage caused by a single subtoxic microdose of carboplatin can predict patient outcomes such as tumor shrinkage, progression free survival and toxicity. The goal of the project is to test the clinical feasibility of PlatinDx in bladder and lung cancer patients. The PlatinDx data will be compared to ERCC1 expression using the Response Genetics RT-PCR assay as a benchmark. The resulting feasibility data will allow the design of a Pivotal Trial, which is required for FDA clearance and product launch.