Objective: The OPTIMAL cohort aims to describe the quality of life and pain perception of patients after local treatment (radiotherapy and/or surgery) of metastases of the long bones, for both the entire cohort as well as for specific treatments separately. With this a more personalized treatment for metastases in the long bones based on expected survival and impending fracture risk can be provided in order to improve functioning and the quality of life for the remaining lifetime in patients with disseminated cancer.