Skeletal malignancies among beagles injected with {sup 241}Am

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Health Physics

DOI:https://doi.org/10.1097/00004032-199402000-00007· OSTI ID:379198

Lloyd, R D; Taylor, G N; Angus, W ^[1]

---

1. Univ. of Utah, Salt Lake City, UT (United States); and others

Seventy skeletal malignancies in 44 dogs were identified among 117 beagles injected as young adults with graded dosages of {approximately}0.07 to 104 kBq {sup 241}Am kg{sup -1} and maintained for lifetime observation. All of these tumors were osteosarcomas except four fibrosarcomas of bone and four chondrosarcomas of bone. Of these 117 animals, 114 survived beyond the minimum age (of 2.79 y) for radiation-induced bone cancer, and all are now dead. An expression was derived that described the dependence of percent occurrence of bone sarcoma on skeletal radiation dose of A = 0.76 + 30D, where A = percent of dogs with skeletal malignancy within any dosage group, D = average skeletal dose (<3 Gy) at 1 y before death (average skeletal dose was calculated to the presumed start of tumor growth, which we have taken to be 1 y before death), and 0.76 represents the lifetime percent malignant bone tumor response among 132 suitable control dogs in our colony not given any radioactivity. All dosage groups with skeletal doses of >3 Gy at 1 y before death exhibited close to 100% occurrence and appeared to be beyond the region of linearity. Therefore, they were excluded from the derivation of this expression. Similar analysis of corresponding data for beagles given {sup 226}Ra as young adults, excluding the two highest dosage groups in which the bone tumor response was {approximately}100%, yielded the expression, A = 0.76 + 4.7D, (D < 20 Gy). A ratio of the coefficients in these two expressions indicates the effectiveness at low radiation doses for bone-cancer induction of {sup 241}Am relative to {sup 226}Ra, or (30 {plus_minus} 2.6)(4.7 {plus_minus} 0.47){sup -1} = 6 {plus_minus} 0.8. This compares to the relative effectiveness at low radiation doses that was obtained earlier for a {sup 239}Pu:{sup 226}Ra toxicity ratio of about 16 {plus_minus} 5. 19 refs., 1 fig., 4 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 379198
• Journal Information: Health Physics, Journal Name: Health Physics Journal Issue: 2 Vol. 66; ISSN HLTPAO; ISSN 0017-9078
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AMERICIUM 241
BEAGLES
BIOLOGICAL RADIATION EFFECTS
FIBROSARCOMAS
INTRAVENOUS INJECTION
OSTEOSARCOMAS
RADIATION DOSES
RADIOINDUCTION
SKELETON
TOXICITY