Planning case report forms for data capture in clinical trials is a labor-insensitive and not formalized process. These CRFs are often neither standardized nor using defined data elements. Metadata registries as the NCI caDSR provide the capability to create forms based on common data elements. However, an exchange of these forms into clinical trial management systems through a standardized format like CDISC ODM is currently not offered. Thus, our objectives were to develop a mapping model between NCI forms and ODM. We analyzed 3012 NCI forms and included common data elements regarding their frequency and uniqueness. In this paper, we have created a mapping model between both formats and identified limitations in the conversion process: Semantic codes requested from the caDSR registry did not allow a proper mapping to ODM items and information like the number of module repetitions got lost. Summarized, it can be stated that our mapping model is feasible. However, mapping of semantic concepts in ODM needs to be specified more precisely.