Rad T 110 State Syllabus for Radiation Protection

The syllabus is published by the State as a reference for issues regarding radiation. There are different syllabi for various aspects of radiology, i.e. radiography, fluoroscopy, mammography, nuclear medicine, etc. State laws pertinent to radiology are enacted by the Legislature on recommendations from various groups including, the Radiologic Technology Certification Committee(RTCC).

The syllabus consists of chapters covering most aspects of radiation exposure. These are the abridged version of the laws. The actual laws are found in Title 17 of the California Code of Regulations.

Chapter 1 Radiation Utilization 15 – 29 y/o (the genetically significant cohort) receive 600 exam/ 1000 people annually. Average # of exams per person imaged was 1.6 at 2.2 films/exam Nationally 43% of the population receive medical x-ray exams while 22% receive dental x-ray exams.

Breakdown of exams by type –Chest 50% –Abdomen 25% –Extremities 17% –Head and neck 8%

Chapter 2 Factors Influencing Patient Dose Topics in this section we have already covered. Gonadal shields are required to have 0.5 mm Pb eq. This stops 92% of the primary beam. Technique charts are required in all x-ray rooms.

Tech controlled dose factors Collimation Gonadal shielding Proper technique Correct positioning Using grids Proper film handling

When to Shield Patient is of reproductive age Shield will not interfere with the exam Gonads are within 5 cm of the primary beam

Chapter 3 Repeat Films 2 categories for repeats –Equipment failure –Technologist error Experienced techs have a <2% repeat rate Inexperienced tech/students can be >10% 50% of retakes are due to technique errors –Positioning errors account for 25% of repeats Ongoing repeat analysis is required. Various abdominal films account for 40% of repeats but only 25% of acquired films

Chapter 4 Pediatric Radiography Shielding Clothing Phototiming Collimation Immobilization

Chapter 5 Computed Tomography A high-dose modality –Brain exams 1-4 rads –Body exams 2-12 rads Essentially no dose to the tech.

Chapter 6 Mobile Radiographic Equipment Switch has to be a dead-man type –The cord for the exposure switch has to be at least 6 ft. Source to skin distance has to be at least 12 inches (30 cm). Personnel monitoring is required

Aprons need to be available with mobile units ‘Exposure rules’ –Anyone in the room needs to be outside the primary beam and away from the patient –Everyone in the room needs an apron –Everyone in the room wear a personnel monitor

Chapter 7 Health Effects of Low-level Radiation Exposure Somatic Dose Indicators –Injuries to skin –Induction of cancer –Fertility problems, cataracts –Injuries to fetus/embryo Most somatic dose indicators are location specific –i.e. cataracts come from eye exposure

Bone marrow –Hematological depression –High marrow dose exams LSP, IVP, Abdominal angio, GI, chest tomos Thyroid and skin –Skin dose is often used as organ dose for adjacent organs

Genetically significant dose (GSD) –Based on future child expectancy, exam rate, gonadal dose/exam In 1970, the GSD was estimated to be 20 mRad annually. –Abdominal exams contribute 70% of the GSD.

Chapter 8 Biologic Effects and Significance of Radiation Dose Biologic effects are influenced by –Dose rate –Total dose –Type of cell irradiated

Radiobiological Injury Cellular amplification Gross cellular effects Latent period

Determinants of Biologic Effect Dose effect curve Area exposed and shielding Cell sensitivity

Cell Sensitivity (most to least) Lymphocytes or WBC Erythrocytes or RBC Epithelial cells Endothelial cells Connective tissue cells

Cell Sensitivity Cont Bone cells Muscle cells Nerve cells Brain cells

Chapter 9 Personnel Radiation Protection Types of effects –Stochastic – probability of the effect occurring (cancer) –Non-stochastic – severity increases with dose - threshold Tech is required by law to stand behind a protective barrier –99.87% reduction in exposure at 100 kVp Aprons, thyroid shields, gloves, glasses – required to have 0.25 mm Pb eq –97% effective against scatter Pts should only beheld in emergencies. –No one should routinely hold pts.

Chapter 10 Personnel Monitoring Record whole body exposure unless specified Example –Film badge –TLD –Pocket ionization chamber Overexposure is considered valid until proven otherwise

MPD Occupational –Whole body 5 REM or 5000 mRem or 0.05Sv –Skin and extremities 50 REM or 0.5 Sv –Eyes 15 REM or 0.15 Sv

MPD Public –Whole body 100 mRem or 0.1 rem or Sv (1mSv) annually rem or 2 mrem per hour

Radiation Areas High radiation area –100 mRem/hr at 30 cm Fluoroscopy and CT Radiation area –5 mRem/hr at 30 cm Monitoring devices have to be worn be individuals doing mobile exams and in high radiation areas.

Chapter 11 Supervision and Use of X-rays on Humans Supervisors are licentiates of the healing arts. They have the ultimate responsibility for ensuring compliance.

Technologist Restrictions Taking films without adequate supervision Exposing pts without an order Operating equipment without training Using a unit without repeat policies Exposing the gonads without shielding if appropriate Interpreting or diagnosing films

Tech restrictions Reporting diagnoses to the pt Performing procedures without being certified Taking films without having your certificate posted Taking films with an expired certificate Using a title indicating the right to practice medicine

Display of Documents Certificates are required to be displayed Cal. Rad Control Regs need to be displayed Notice to Employees needs to be displayed