Purpose To establish a gold-standard methodology for accurately extracting progression-free survival (PFS) following Diffuse Large B-Cell Lymphoma (DLBCL) treatment using real-world electronic healthcare record (EHR) data. Results We produced an R Shiny application which can capture, annotate, and transform unstructured EHR data into structured data - specifically, treatment lines, cycles, and response criteria with corresponding dates - ready for analysis of PFS. An annotation schema for capturing real-world data was also developed. Mapping of common phrases used by clinicians in real-world practice to response criteria resulted in a dictionary of these phrases.