Alterations in protein-protein interaction networks are at the core of malignant transformation but have yet to be translated into appropriate diagnostic tools. We make use of the kinetic selectivity properties of an imaging probe to visualize and measure the epichaperome, a pathologic protein-protein interaction network. We are able to assay and image epichaperome networks in cancer and their engagement by inhibitor in patients' tumors at single-lesion resolution in real time, and demonstrate that quantitative evaluation at the level of individual tumors can be used to optimize dose and schedule selection. We thus provide preclinical and clinical evidence in the use of this theranostic platform for precision medicine targeting of the aberrant properties of protein networks. Display omitted •Pathologic protein networks and their engagement in clinic are monitored by imaging•Real-time tumor pharmacometric data are obtained at the level of individual tumors•Theranostic and clinical assay combined provide quantitative tumor measurements•The platform provides dose and schedule information for epichaperome targeting Pillarsetty et al. demonstrate the ability to visualize the epichaperome, a pathologic protein-protein interaction network, and to measure inhibitor engagement from mice and patients at single-tumor resolution in real time, which facilitates the optimization of dose and schedule selection.