CARCINOGENESIS BY IONIZING RADIATIONS 



1181 



literature twenty-four cases (Fig. 18-9). In all except six the irradiation 

 was given for chronic joint infection. In three cases bone sarcoma 

 resulted from irradiation given for the treatment of other tumors. In all 

 but one case a large amount of radiation was administered in fractional 

 doses over a long period. The median interval between irradiation and 

 recognition of sarcoma was six years; the shortest interval was three 

 years; the longest, eleven years. Chondrosarcoma occurred more fre- 

 quently among irradiation-produced sarcomas than among other spon- 

 taneous bone tumors. The degree of bone formation in the tumors was 

 variable; those in which none was found were labeled as polymorphous 

 or spindle-celled sarcomas. 



Fig. 18-9. Osteogenic sarcoma induced in man by X rays (after Hatcher, 1945). 



Cahan et at. (1948) collected from the literature seventeen cases of 

 bone sarcomas following radium or roentgen radiation therapy reported 

 until 1948 (exclusive of Mainland's cases of radium dial painters) and 

 described eleven additional cases observed by them. The first thirteen 

 cases noted between 1922 and 1937 occurred in patients receiving thera- 

 peutic irradiation for bone tuberculosis. The patients were eleven to 

 forty years old at the onset of the neoplasm. Three to ten years elapsed 

 between irradiation and the discovery of the tumor. The bone sarcomas 

 were variously described as spindle-celled, pleomorphic, giant-celled, 

 chondro-fibro-osteosarcoma, and osteo-chondro-myxosarcoma. The sub- 

 sequent four cases described between 1939-45 occurred in patients 

 twenty-three to fifty-six years old receiving treatment for chronic 

 arthritis, benign giant-cell tumor, chondroblastoma, or as a "prophy- 

 lactic" measure following removal of carcinoma of the breast. It was 

 subsequently pointed out by several investigators that the irradiation of 

 benign giant-cell tumors is hazardous, as it is likely to cause a malignant 

 transformation of this neoplasm. Jaffe and Selin (1951) noted an appar- 

 ent increase in the number of malignant metastasizing giant-cell tumors 

 since the beginning of the era of radiation therapy of this tumor. 



The eleven cases of bone tumor following X irradiation, well studied 



