The influence of changing dose rate patterns from inhaled beta-gamma emitting radionuclide on lung cancer. (2nd November 2018)

• Record Type: Journal Article
• Authors: Puukila, Stephanie; Thome, Christopher; Brooks, Antone L.; Woloschak, Gayle; Boreham, Douglas R.
• Is Part Of: International journal of radiation biology. Volume 94:Number 11(2018)
• Page Start: 955
• Page End: 966
• Publication Date: 2018-11-02
• Subjects: Dose rate -- radiation -- inhaled radionuclides -- radiation-induced lung cancer; Radiation -- Physiological effect -- Periodicals; Radiobiology -- Periodicals; 571.45
• DOI: 10.1080/09553002.2018.1511929
• Languages: English
• ISSNs: 0955-3002

Abstract

Abstract: Purpose: Dose and dose rate are both appropriate for estimating risk from internally deposited radioactive materials. We investigated the role of dose rate on lung cancer induction in Beagle dogs following a single inhalation of strontium-90 ( 90 Sr), cerium-144 ( 144 Ce), yttrium-91 ( 91 Y), or yttrium-90 ( 90 Y). As retention of the radionuclide is dependent on biological clearance and physical half-life a representative quantity to describe this complex changing dose rate is needed. Materials and methods: Data were obtained from Beagle dog experiments from the Inhalation Toxicology Research Institute. The authors selected the dose rate at the effective half-life of each radionuclide (DRef ). Results: Dogs exposed to DRef (1–100 Gy/day) died within the first year after exposure from acute lung disease. Dogs exposed at lower DRef (0.1–10 Gy/day) died of lung cancer. As DRef decreased further (<0.1 Gy/day 90 Sr, <0.5 Gy/day 144 Ce, <0.9 Gy/day 91 Y, <8 Gy/day 90 Y), survival and lung cancer frequency were not significantly different from control dogs. Conclusion: Radiation exposures resulting from inhalation of beta-gamma emitting radionuclides that decay at different rates based on their effective half-life, leading to different rates of decrease in dose rate and cumulative dose, is less effective in causing cancer than acute low linear energy transfer exposures of the lung.