Low energy scatter due to in-situ irradiation of solid tumors in laboratory rats

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1980

OSTI ID:5462836

Ritenour, Jr, E R

A study of the pattern of scattered radiation in laboratory rat cadavers during irradiation of solid tumors on the animals' flanks was performed. The animals were wrapped in a lead shield having a circular cutout through which the tumor protruded. Irradiations were performed with a 250 kVp 15ma X-ray machine with a measured half value layer of 1.39 mmCu. Lead shielding was of sufficient thickness to attenuate essentially all of the beam. The absorbed dose measured in the animal was then due to internal scatter from the tumor. Arrays of thermoluminescent dosimeters (TLDs) were placed beneath the skin of 17 animals bearing a solid tumor (hepatoma H-4-II-E). Absorbed dose was seen to vary isotropically, decreasing as the inverse distance squared from the tumor. Analysis of experimental error played a major role in this study. A pilot study resulted in standard errors that were 35% of the mean absorbed dose measurements. A careful reassessment of methods of manipulating the animals and the dosimetry system resulted in a reduction in standard error to 14% of the mean for small groups (less than 10 animals).

• OSTI ID: 5462836
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
61 RADIATION PROTECTION AND DOSIMETRY
HEPATOMAS
BIOLOGICAL RADIATION EFFECTS
X RADIATION
SCATTERING
ERRORS
PHANTOMS
RADIATION DOSES
RATS
SHIELDING
THERMOLUMINESCENT DOSEMETERS
ANIMALS
BIOLOGICAL EFFECTS
DISEASES
DOSEMETERS
DOSES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
LUMINESCENT DOSEMETERS
MAMMALS
MEASURING INSTRUMENTS
MOCKUP
NEOPLASMS
RADIATION EFFECTS
RADIATIONS
RODENTS
STRUCTURAL MODELS
VERTEBRATES
560152* - Radiation Effects on Animals- Animals
655003 - Medical Physics- Dosimetry