The influence of changing dose rate patterns from inhaled beta-gamma emitting radionuclide on lung cancer.

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 (90Sr), cerium-144 (144Ce), yttrium-91 (91Y), or yttrium-90 (90Y). 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 90Sr, <0.5 Gy/day 144Ce, <0.9 Gy/day 91Y, <8 Gy/day 90Y), 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.

• Authors: Stephanie Puukila, Christopher Thome, Antone L Brooks, Gayle Woloschak, Douglas R Boreham
• Journal: International journal of radiation biology (Int J Radiat Biol) Vol. 94 Issue 11 Pg. 955-966 (11 2018) ISSN: 1362-3095 [Electronic] England
• PMID: 30257126 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Administration, Inhalation
• Animals
• Beta Particles (adverse effects)
• Dogs
• Gamma Rays (adverse effects)
• Half-Life
• Lung Neoplasms (etiology)
• Neoplasms, Radiation-Induced (etiology)
• Radiation Dosage
• Risk Assessment