Occupational Radiation Safety & VFSS

Primary source of radiation exposure for SLPs during VFSS

Scatter radiation emitted directly from the patient.

ALARA philosophy

As Low As Reasonably Achievable; keeping radiation exposure to the minimum possible.

Three cardinal rules of radiation protection

Time, Distance, and Shielding.

How the Inverse Square Law affects radiation exposure

Doubling distance from the radiation source reduces exposure to one-fourth.

Why gloved hands should never enter the primary x-ray beam

Automatic exposure controls will automatically ramp up radiation intensity.

Dosimetry requirement for declared pregnant healthcare workers

Dual dosimetry monitoring: one badge at the collar and one at the waist under the apron.

OSHA annual occupational whole-body radiation dose limit

5 rem (50 mSv) per year.

Occupational fetal radiation dose limit for declared pregnant workers

0.5 rem (5 mSv) over the entire pregnancy.

TLD in radiation monitoring

Thermoluminescent Dosimeter; a badge worn to track cumulative occupational radiation exposure.

Deterministic vs. stochastic radiation effects

Deterministic effects occur above a dose threshold; stochastic effects (like cancer) have no threshold.

Linear Non-Threshold (LNT) Model

Model assuming any radiation dose carries a proportional increase in lifetime cancer risk.

CT scans proportion of US man-made radiation exposure

CT represents ~15% of procedures but 48% of total man-made radiation exposure.

Reasons children are more radiosensitive than adults

Rapidly dividing tissues and longer remaining lifespans for late-onset cancers to manifest.

Age-related risk drop for radiation-induced thyroid cancer

Relative risk decreases by 56% for every 10-year increase in age at exposure.

Minimum thyroid radiation dose linked to papillary thyroid cancer risk

Doses as low as 50-100 mGy.

Common genetic mutation in radiation-induced papillary thyroid cancer

RET proto-oncogene chromosomal rearrangements (e.g., RET/PTC1).

Dose reduction from thyroid shielding and optimization strategies

Reduces absorbed organ radiation dose by 50% to 60%.