Endosteum

A 50-μm-thick layer covering the surfaces of the bone trabeculae in regions of trabecular spongiosa and those of the cortical surfaces of the medullary cavities within the shafts of all long bones. It is assumed to be the target region for radiogenic bone cancer. This target region replaces that previously introduced in Publications 26 and 30 (ICRP 1977; 1979a), the bone surfaces, which had been defined as a single-cell layer 10 μm in thickness covering the surfaces of both the bone trabeculae and the Haversian canals of cortical bone.

ICRP Publication 130, 2015

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from ICRP Publication 133, 2016

A 50-μm-thick layer covering the surfaces of the bone in regions of trabecular spongiosa and surfaces of the medullary activities within the shafts of the long bones. It is assumed to be the target region for radiogenic bone cancer. The mass of the endosteum is 0.58 and 0.43 kg in the adult reference male and female respectively. This target replaces the bone surface target of ICRP Publication 26 and ICRP Publication 30 (1977 1979 1980 1981 1988) which was defined as a 10 μm layer of mass 0.12 kg.

from ICRP Publication 116, 2010

A 50-μm-thick layer covering the surfaces of the bone trabeculae in regions of trabecular spongiosa and those of the cortical surfaces of the medullary cavities within the shafts of all long bones. It is assumed to be the target tissue for radiogenic bone cancer. This target region replaces that previously introduced in ICRP Publication 26 and ICRP Publication 30 (ICRP, 1977, 1979) – the bone surfaces – which had been defined as a single-cell layer, 10 μm in thickness, covering the surfaces of both the bone trabeculae and the Haversian canals of cortical bone.

from ICRP Publication 110, 2008

A 50-μm-thick layer covering the surfaces of the bone trabeculae in regions of trabecular spongiosa and the cortical surfaces of the medullary cavities of the shafts of all long bones. It serves as the target tissue for radiogenic bone cancer. In contrast to previous assumptions, recent studies have indicated that the cells at risk for bone cancer induction are localised out to 50 μm (previously assumed: 10 μm) from both the trabecular surfaces and interior cortical surfaces of the medullary cavities, but not within the Haversian canals of cortical bone.