ISO 16637:2016

Overview

ISO 16637:2016 - Radiological protection - Monitoring and internal dosimetry for staff members exposed to medical radionuclides as unsealed sources - specifies minimum requirements for designing professional monitoring programmes for internal contamination risk in nuclear medicine. The standard provides principles for setting compatible goals, selecting suitable monitoring methods, and conducting dose assessments for workers exposed to unsealed radionuclide sources in diagnostic and therapeutic departments.

Key topics and technical requirements

ISO 16637:2016 covers practical and procedural elements needed to implement reliable workplace monitoring and internal dosimetry:

• Purpose and categories of monitoring programmes (routine, triage, special, confirmatory, task‑related).
• Quantitative criteria for when to conduct monitoring and how to prioritize measurements.
• Selection of monitoring methods, with criteria for choosing in vivo (whole‑body/thyroid counting) and in vitro (bioassay) approaches without prescribing detailed techniques.
• Design information required for programme development (work tasks, radionuclides, exposure pathways).
• Performance requirements, e.g. detection limits, decision thresholds, tolerated uncertainties and derived recording levels.
• Measurement frequencies and procedures for routine vs. special monitoring.
• Dose assessment procedures using reference levels, assumptions for dose‑critical parameters, and interpretation criteria for individual and workplace results.
• Uncertainty analysis, reporting/documentation and quality assurance requirements for monitoring and dose assessment processes.

The standard explicitly excludes laboratory radioimmunoassay monitoring, PET cyclotron maintenance, litigation dosimetry, ingestion/wound dosimetry, detailed measurement technique descriptions, and modelling improvements.

Practical applications and users

ISO 16637:2016 is intended for organizations and professionals responsible for radiation protection in medical settings:

• Radiation Protection Officers (RPOs) and medical physicists designing workplace monitoring programmes.
• Nuclear medicine departments implementing routine and special monitoring for staff who handle unsealed radionuclides.
• Health physicists and dosimetrists performing internal dose assessments and interpreting bioassay/in vivo data.
• Regulatory authorities and employers establishing compliant occupational radiation safety programs.
• Bioassay laboratories and in vivo counting facilities aligning reporting and quality assurance with accepted criteria.

Use this standard to create consistent, defensible monitoring strategies that improve worker safety and regulatory compliance in nuclear medicine.

Related standards

• ISO 20553:2006 - Monitoring of workers occupationally exposed to internal contamination
• ISO 28218:2010 - Performance criteria for radiobioassay
• ISO 27048:2011 - Dose assessment for monitoring of workers for internal radiation exposure

Keywords: ISO 16637:2016, radiological protection, internal dosimetry, nuclear medicine monitoring, unsealed sources, bioassay, in vivo counting, dose assessment.