ICRP Publication 133: The ICRP computational framework for internal dose assessment for reference adults: specific absorbed fractions

Abstract

Dose coefficients for assessment of internal exposures to radionuclides are radiological protection quantities giving either the organ equivalent dose or effective dose per intake of radionuclide following ingestion or inhalation. In the International Commission on Radiological Protection’s (ICRP) Occupational Intakes of Radionuclides (OIR) publication series, new biokinetic models for distribution of internalised radionuclides in the human body are presented as needed for establishing time-integrated activity within organs of deposition (source regions). This series of publications replaces Publications 30 and 68 (ICRP, 1979, 1980, 1981, 1988, 1994b). In addition, other fundamental data needed for computation of the dose coefficients are radionuclide decay data (energies and yields of emitted radiations), which are given in Publication 107 (ICRP, 2008), and specific absorbed fraction (SAF) values – defined as the fraction of the particle energy emitted in a source tissue region that is deposited in a target tissue region per mass of target tissue. This publication provides the technical basis for SAFs relevant to internalised radionuclide activity in the organs of Reference Adult Male and Reference Adult Female as defined in Publications 89 and 110 (ICRP, 2002, 2009). SAFs are given for uniform distributions of mono-energetic photons, electrons, alpha particles, and fission-spectrum neutrons over a range of relevant energies. Electron SAFs include both collision and radiative components of energy deposition. SAF data are matched to source and target organs of the biokinetic models of the OIR publication series, as well as the Publication 100 (ICRP, 2006) Human Alimentary Tract Model and the Publication 66 (ICRP, 1994a) Human Respiratory Tract Model, the latter as revised within Publication 130 (ICRP, 2015). This publication further outlines the computational methodology and nomenclature for assessment of internal dose in a manner consistent with that used for nuclear medicine applications. Numerical data for particle-specific and energy-dependent SAFs are given in electronic format for numerical coupling to the respiratory tract, alimentary tract, and systemic biokinetic models of the OIR publication series.

Whole-Body Biodistribution and Dosimetry of the Dopamine Transporter Radioligand 18F-FE-PE2I in Human Subjects

“…The PET images were decay-corrected to the start of the scan. The mean activity concentrations (Bq/mL) in different organs as obtained from the PET images were transformed to total activity content by multiplying by the organ masses, including blood content (g), for males or females from International Commission on Radiological Protection publication 133 (16). For lungs, the activity concentration was multiplied by the lung volume, which was calculated by dividing the mass by the density (0.38 g/mL).…”

Quantitative impact of changes in marrow cellularity, skeletal size, and bone mineral density on active marrow dosimetry based upon a reference model

“…S values in this study were computed via an in‐house MATLAB™ script using values of particle energies and yields taken from ICRP Publication 107, which include the full spectrum of beta‐particle energies. Dose contributions by alpha‐particle recoil nuclei were evaluated using extrapolated SAFs for 2‐MeV alpha particles — an approach identical to that made by the ICRP in their Publication 133 . S values are reported here in the units of mGy per MBq‐s.…”

“…Dose contributions by alpha-particle recoil nuclei were evaluated using extrapolated SAFs for 2-MeV alpha particles an approach identical to that made by the ICRP in their Publication 133. 29 S values are reported here in the units of mGy per MBq-s. It is further noted that the focus of this study was on interpatient variability in marrow dose embodied in the radionuclide S value.…”

Depth‐dependent concentrations of hematopoietic stem cells in the adult skeleton: Implications for active marrow dosimetry

“…S values reported in this study were computed via an in‐house MATLAB™ script using values of particle energies and yields taken from ICRP Publication 107, which include the full spectrum of beta‐particle energies. Dose contributions by alpha‐particle recoil nuclei were evaluated using extrapolated SAFs for 2‐MeV alpha particles — an approach identical to that made by the ICRP in their Publication 133 . S values are reported here in the units of mGy per MBq‐s.…”

“…Dose contributions by alpha-particle recoil nuclei were evaluated using extrapolated SAFs for 2-MeV alpha particlesan approach identical to that made by the ICRP in their Publication 133. 36 S values are reported here in the units of mGy per MBq-s. As originally outlined in Watchman et al, 7 depth-dependent weighting factors may be derived to compute corresponding depth-dependent radionuclide S values for bone-seeking radionuclides. In this study, these weighting factors are based on study data from Bourke et al 8 which included depth-dependent CD34 + areal concentrations from the iliac crest, ribs, and L 1 vertebrae taken from eight patients at autopsy.…”