There is disclosed a process for determining early patient response to an initial therapy administration, comprising a rapid determination of effectiveness of a therapy after an initial treatment for a cancer indication. More specifically, the rapid determination of effectiveness is made days following initial therapy. There is further disclosed a process for determining early patient response to an initial cancer treatment, comprising (a) conducting a baseline PET FDG or PET FLT scan of the tumor region in a patient by determining tumor tissue metabolic rate and/or apoptotic rate (for FLT), (b) providing a single potentially effective dose of a therapeutic to the patient, (c) conducting a second PET FDG or PET FLT scan by determining tumor tissue metabolic rate, and (d) comparing the results of the first PET scan to the second PET scan to determine an imaging response in the PET scan results whereby at least a 1% reduction in tumor tissue metabolic rate indicates that the patient would benefit to treat the tumor with the initial cancer treatment. Preferably, in addition to the PET scans conducted before and after an initial dose of a cancer drug, the present disclosure further provides parallel before and after measurement(s) of the level of circulating tumor DNA (ctDNA) for specific oncogene mutations/alterations to identify early patient response to drug therapy.
