1182 RADIATION BIOLOGY 



by Cahan et al. (1948), occurred in patients from nine to fifty-nine years 

 of age. Some were treated for nonmalignant bone disease, such as 

 ossifying fibroma, bone cyst, osteoid osteoma, fibrous dysplasia, and 

 benign giant-cell tumor, or for nonosseous malignant tumor, as retino- 

 blastoma, or for an inflammatory process, as "cloudiness" of antrum. 

 This recalls earlier observations of bone tumor induction by X-radiation 

 treatment given for joint tuberculosis and the experimental work of 

 Lacassagne (1936), who induced varied neoplasms by irradiation of 

 chronic inflammatory tissue. The estimated tumor dose in the patients 

 of Cahan et al. varied between approximately 1550 to 16,000 r and the 

 interval between the last irradiation and onset of bone tumor varied 

 from six to twenty-two years. To one of the eleven patients, the X- 

 radiation treatment was administered to the site of a bone fracture follow- 

 ing radical mastectomy. It seems probable that osteoblastic activity at 

 the time of irradiation facilitated the induction of these neoplasms ; osteo- 

 blasts are highly sensitive to irradiation. 



Most internal tumors in man exposed to either X radiation or radio- 

 active substances arose in bones. Auerbach et al. (1951) reported an 

 extraskeletal osteogenic sarcoma originating in soft tissues of the back. 

 This tumor arose directly beneath the skin in an area that four years 

 previously had received a skin dose of 4000 r of X radiation delivered in 

 ten exposures over a period of 70 days. The rare occurrence of extra- 

 osseous bone tumors following irradiation can be explained by osteogenic 

 metaplasia at sites of chronic inflammation. 



The characteristic sequence of changes in bone following irradiation 

 and preceding the carcinogenic transformation has been described by 

 Ewing (1926), who named this change "radiation osteitis." This is 

 essentially a degenerative change with necrosis and reactive atypical new 

 bone formation and is similar following all types of irradiations. (For 

 recent references, see Koletsky et al., 1950.) 



Bone Tumors in Radium Dial Painters. An industrial hazard occur- 

 ring in New Jersey, well followed by Martland (1931), claimed forty-one 

 victims during a period of some twenty years. Between 1916 and 1925 

 dial painters moistened, by licking, brushes which had been dipped into 

 the luminous compound containing radium and mesothorium. This 

 material ingested over many years lodged in the bones, causing severe 

 anemia and bone tumors. Death occurred within four to six years after 

 ingestion ceased. Autopsy revealed the outstanding changes were 

 necrosis of the jaw and aplastic anemia. The bone changes first noted 

 were those of radiation osteitis (Martland et al., 1925). Later (1931), 

 bone tumors developed in many foci, and death was caused from metas- 

 tases of one of these growths. At autopsy, Martland found other primary 

 bone tumors and transitional changes from radiation osteitis to malignant 

 growth. Thus far (Martland, 1951, personal communication), fourteen 



