Radiobiology and Radiation Safety
Core concepts
Understand radiation biology: deterministic vs stochastic effects, dose thresholds, and the linear no-threshold model. Know radiosensitivity (Bergonié-Tribondeau law: rapidly dividing cells most sensitive). Learn radiation protection principles: justification, optimisation (ALARA), and dose limits. Know occupational and patient dose monitoring. Understand acute radiation syndrome and radiation-induced cancers. Know the international framework (ICRP) and local regulations.
Traps
- Deterministic effects have thresholds; stochastic effects are probabilistic.
- ALARA applies to all exposures-not just occupational.
- Pregnancy requires special consideration-justify and optimise.
- Do not confuse Gy (absorbed dose) with Sv (equivalent/effective dose).
- Radiosensitivity varies by tissue and age.
Worked example / rule of thumb
A pregnant patient needs imaging: justify the examination, consider alternatives (ultrasound/MRI), and optimise dose. Rule of thumb: deterministic = threshold; stochastic = no threshold. For occupational dose, time, distance, shielding are the key controls.
Key points
- Deterministic vs stochastic effects.
- ALARA applies to all exposures.
- Justify and optimise in pregnancy.
- Gy vs Sv: know the difference.
- Time, distance, shielding for occupational protection.
Radiology Quality, Safety and Professional Practice
Core concepts
Understand quality assurance and audit: standards, indicators, and the cycle of improvement. Know reporting standards: structured reports, communication of critical results, and documentation. Learn patient safety: contrast reactions, infection control, and radiation safety. Understand professionalism: consent, confidentiality, and multidisciplinary teamwork. Know error types and the role of root cause analysis. Understand governance and accreditation.
Traps
- Critical results must be communicated and documented-not just reported.
- Consent is required for invasive procedures-know the exceptions.
- Audit is not the same as research-know the difference.
- Error is often systemic-avoid blaming individuals.
- Do not neglect infection control in interventional practice.
Worked example / rule of thumb
A critical finding (e.g., tension pneumothorax) must be communicated directly to the treating team and documented. Rule of thumb: if it changes management, communicate it directly. For quality, measure, analyse, improve, re-audit.
Key points
- Communicate and document critical results.
- Consent for invasive procedures.
- Audit vs research.
- Systemic approach to error.
- Infection control in IR.