Radiation therapy is a standard of care treatment modality for many malignancies and while often curative, it is associated with acute and late toxicities that compromise the nutritional status of cancer patients. Malnutrition is a prognostic indicator of survival in cancer patients, with 20-40% of cancer patients in high income countries dying from malnutrition rather than cancer itself. This CRP will contribute new knowledge about the impact of radiotherapy on body composition in low-and middle-income countries, the causative factors related to body composition changes in patients undergoing radiotherapy, the prognostic and predictive relationships between body composition and outcomes for patients receiving radiotherapy and the efficacy and feasibility of body composition assessments in detecting prognostically significant sarcopenia in patients receiving radiotherapy.? This information will enhance the Member States capabilities to detect malnutrition in cancer patients and provide the evidence required for nutrition care to be optimized for patients receiving radiotherapy. This is a joint CRP of NAHRES and ARBR, NAHU. a href="