B - Radiation Protection

Question 1

What are the General principles of radiation protection?

Answer 1

Any exposure is potentially harmful, so all must be:
Justified, so that benefit outweighs the harm
Optimised, to yield max benefit from amount of radiation used, and following the ALARP principle (as low as reasonably possible/practical) (ALARP)
Dose limits NOT APPLICABLE to patients
adhere to Dose Reference Levels

Question 2

How to we protect and prevent staff and patients?

Answer 2

Radiation Protection
Staff
PPE
Dose Badges
Patients
LMP
Clinical Justification
Members of public
DRL/DAP
Practices and Principles
Legislation

Question 3

What is the PPE for staff?

Answer 3

Staff PPE – Personal Protective Equipment. Must be available in all radiology departments. This is usually:
Lead apron – 0.25mm OR 0.5mm lead equivalence
Thyroid shield
Lead gloves – Used primarily in surgical or fluoroscopy procedures
Lead glasses – 0.75mm lead equivalence
Dose Badges – These record personal exposure to radiation. Should have a threshold.
Legislation

Question 4

How do we protect patients?

Answer 4

Patients
LMP – This is a pregnancy check (Last Menstrual Period). Consists of:
10 day rule: For higher dose exams i.e. CT, Nuclear Medicine.
28 day rule: For lower dose exams i.e. x-ray
For these rules you will need to know the first day of the patients last menstrual period, then, if that is more than 10/28 days ago then a pregnancy check will be required
Clinical Justification – Is this examination necessary?
Cochrane’s Law : “Before you request a test, you should first ask yourself what you are going to do if the test is positive, then ask yourself what you are going to do if the test is negative. If the answer is the same, do not do the test.
Members of public – Lead lines rooms. Lights above doors. Lock the door!!!

Question 5

What is the pregnancy status?

Answer 5

Female patients 12-55 years (anyone who is menstruating can get pregnant, the age range is a guide! Use common sense!)
When primary beam below the diaphragm and above the knee
Initial question asked, “is there any chance you may be pregnant?”
If answer no, patient completes declaration form able to proceed with x-ray examination
If patient not certain apply 28 day rule, rebook examination when appropriate.
Risk v benefit analysis may determine examination to proceed regardless

Question 6

What is Dose Reference Levels (DRL’S)?

Answer 6

Average patient dose for each projection. National DRL’s based on 70kg patient. These are a guidance.
Local DRL’s recommended for local population
We must record all our doses and provide evidence of this in order to establish DRL’s

Question 7

What is Dose Area Product (DAP)?

Answer 7

Skin surface dose based on exposure set and collimation
Both operator dependant
Local and National DRL’s can be based on DAP readings

Question 8

We can achieve this ALARA As Low As Reasonable Acceptable principle by considering 3 things. What are they?

Answer 8

Time – Keep exposure times short
Distance – Be correct distance from x-ray source to reduce unnecessary dose
Shielding – Apply all appropriate lead protection

Question 9

How do we reduce unnecessary doses?

Answer 9

No unnecessary exams
Justify every exposure
No repeat exams
Take care when positioning
Radiographic technique
Highest kVp appropriate to body area
Patient positioning
Primary beam not hitting other body areas (e.g. patient seated for extremity exam should have legs to side)
Shielding
Gonads ( eyes, thyroid, not usual for chiropractic examinations )
Good communication with the patient