Dosimetries

Dosimetries refers to the field and practice of dosimetry, the measurement and calculation of the absorbed dose delivered by ionizing radiation to matter, particularly human tissue. It supports clinical procedures such as radiology, radiation therapy, and nuclear medicine, as well as occupational safety and environmental monitoring. The absorbed dose is measured in grays (Gy), while equivalent dose and effective dose use sieverts (Sv) to account for radiation type and tissue sensitivity. Dosimetries combines direct measurements with computational modeling to estimate dose distributions within bodies and environments.

Physical dosimetry uses instruments such as ionization chambers, semiconductor detectors, thermoluminescent dosimeters (TLDs), and optically stimulated luminescence dosimeters (OSLDs) to quantify dose. Biological dosimetry relies on cellular or molecular indicators of exposure, such as chromosomal damage, when physical measurements are impractical. In clinical settings, dosimetry includes beam calibration, dose calculations, and treatment planning system modeling, following standardized protocols (for example, TG-51 in radiotherapy). Specialized forms exist for brachytherapy, external beam therapy, and nuclear medicine, each with tailored calibration and verification procedures.

Guidance comes from international bodies such as the ICRP, ICRU, and IAEA, with occupational monitoring often employing wearable dosimeters. Advances in dosimetries include three-dimensional and gel dosimetry, in vivo dosimetry during treatments, and patient-specific or personalized dosimetry to improve accuracy and safety. Ongoing challenges involve reducing uncertainties, accounting for tissue heterogeneity and complex geometries, and integrating dosimetric data into clinical decision-making to optimize therapeutic benefit while minimizing risk.