Role of therapeutic radiology in cancer of bone.

Management of patients with Ewing's sarcoma has been discussed with reference to the need to achieve an excellent local result from radiation therapy now that patients are experiencing long-term survival. The technique of biopsy is important: small scar; located within treatment portal; positioning such that there is a good connective tissue bed (e.g. not immediately overlying bone); tissue obtained from soft tissue component and no cortical bone removed. Radiation therapy technique is based upon: special shaping of the irradiated volume to correspond to estimate distribution of tumor; distribution of dose in accordance with tumor cell number (progressive field reduction); precision setup of patient each day; and high total dose (6000-6600 rads in 6-6.6 weeks). This treatment is to be given in combination with multidrug multicycle chemotherapy. For osteosarcoma, special attention was given to lesions of mandible, where preoperative irradiation and hemimandibulectomy appears to be much more effective than surgery alone.