After removing resectable lesions at operation, residual cancer nests were sterilized by irradiation before surgical closure. The great advantage of intraoperative radiotherapy lies in the treatment of lesions such as gastric cancers located near radiosensitive organs, and radioresistant tumors, such as soft-tissue sarcoma. Since the lesion is exposed directly to irradiation, a cancerocidal dose can be delivered without affecting normal structures. Clinical results have shown that cure can be expected following excision of the primary mass.