Radiotherapy is a very important type of treatment in multiple myeloma as it is a very effective way of killing myeloma cells and reducing pain in affected areas. If an x-ray film reveals a significant lytic lesion in the skeleton, we consider appropriate to employ radiotherapy even if it is still not painful. The aim of the procedure is to stop progression of the lesion and prevent pathologic fracture that would limit the patient´s mobility. Lytic lesion in extra-skeletal sites are treated with radiotherapy in case they are painful or if they could result in a pathologic fracture. Radiotherapy is a regular part of the treatment of every myeloma patient. In some patients, a control x-ray films reported osteosclerotic changes due to radiation and to its probably bone strenghtening effect.