An Epidemiological Assessment of Lens Opacifications That Impaired Vision in Patients Injected with Radium-224

• Published in: Radiation research Vol. 115; no. 2; pp. 238 - 257
• Main Authors: Chmelevsky, D., Mays, C. W., Spiess, H., Stefani, F. H., Kellerer, A. M.
• Format: Journal Article
• Language: English
• Published: Oak Brook, Il Academic Press, Inc 01-08-1988; Radiation Research Society
• Subjects: Adult; Age Factors; Ankylosing spondylitis; Biological and medical sciences; Biological effects of radiation; Body Weight; Cataract - epidemiology; Cataract - etiology; Cataracts; Child; Dose-Response Relationship, Radiation; Female; Follow-Up Studies; Fundamental and applied biological sciences. Psychology; Humans; Ionizing radiations; Male; Middle Aged; Modeling; Models, Biological; Parametric models; Radiation dosage; Radiation Injuries - epidemiology; Radiation Injuries - etiology; Radiobiology; Radiotherapy; Radium - adverse effects; Spondylitis, Ankylosing - complications; Spondylitis, Ankylosing - radiotherapy; Thorium; Time dependence; Time Factors; Tissues, organs and organisms biophysics; Tuberculosis; Human; Eye; Opacification; Cataract; Ionizing radiation; Radiobiology; Irradiation; Epidemiology; Radium
• ISSN: 0033-7587; 1938-5404
• DOI: 10.2307/3577161

The incidence of lens opacifications that impaired vision (cataract) was analyzed among 831 patients who were injected with known dosages of ^{224}{\rm Ra}$ in Germany shortly after World War II. The dependence of the incidence on dosage, i.e., injected activity per unit body weight, and on time after treatment was determined. The observations are equally consistent with proportionality of the incidence of cataract to the square of dosage or with a linear dependence beyond a threshold of 0.5 MBq/kg. The possibility of a linear dependence without threshold was strongly rejected (P < 0.001). The analysis of temporal dependences yielded a component that was correlated with the injected amount of ^{224}{\rm Ra}$ and a component that was uncorrelated. The former was inferred by a maximum likelihood analysis to increase approximately as the square of the time after treatment. The component unrelated to the treatment was found to increase steeply with age and to become dominant within the collective of patients between age 50 and 60. The relative magnitudes of the two components were such that a fraction of 55 to 60% of the total of 58 cataracts had to be ascribed to the dose-related incidence. Impaired vision due to cataract was diagnosed before age 54 in 25 cases. In terms of injected activity per unit body weight no dependence of the sensitivity on age was found; specifically there was no indication of a faster occurrence of the treatment-related cataracts in patients treated at older ages.