Personal Radiation and Occupational Safety – CT

Policy• This policy is in both paper form in the

lab’s compliance manual, and on a Power Point presentation in order that one could provide the annual in-service or an in-service to new employees of the practice.

• The policy will be reviewed by on an annual basis.

• Policy created: December 15, 2008

Responsibilities

• The Radiologist: To ensure that procedures are conducted in such a manner as to minimize exposure to patients, public, and employees.

Responsibilities

• The Radiographer:

• The radiographer must acquire the daily quality control testing to ensure that the CT system is operating is a safe manner.

• The radiographer must conduct his/her radiation safety behavior according to the principles of ALARA (As Low as Reasonably Achievable)

Responsibilities

• Field Service Engineer

• The field service engineer must conduct the manufacturers required PMs (Preventive Maintenance) and ensure that all system components are operational.

Responsibilities

• Physicist.

• The physicist must acquire testing as required by law to ensure that radiation doses to both patients, and personnel, are ALARA.

Helpful Information for Cardiology

• Health Physics Society Ask The Experts

http://hps.org/publicinformation/asktheexperts.cfm

• Physicist Contact Number:

Radiation Dose Limits

Type Annual Limit

Whole Body 5,000 millirem

Extremities 50,000 mrem

Lens of the Eye 15,000 mrem

Embryo/Fetus 500 mrem

ALARA Dose Levels

• To help maintain radiation doses ALARA, there are two dose Action Levels.

• ALARA Level 1: 125 mrem/calendar quarter.

• ALARA Level 2: 375 mrem/calendar quarter.

ALARA Level 1

• Level 1 is set at 10% of the annual limit, or 125 mrem per quarter. Technically, only those who receive a dose above Level 1 are required to wear a film badge.

• A report is made to the Radiation Safety Physicist of all doses exceeding the Level 1 threshold.

ALARA Level 2

• Level 2 is set at 30% of the annual dose limit, or 375 mrem per quarter.

• Your physicist investigates all exposures exceeding Levels 1 and 2, makes any appropriate dose level reduction recommendations, and reports to you and the Medical Director of the Practice.

ALWAYS WEAR YOUR DOSIMETER WHILE WORKING

• Failure to wear your dosimeter while working in the CT area makes it extremely difficult for the health physicist to obtain an accurate assessment of your exposure.

• Also, do not wear the same dosimeter if you are working another job where you may be exposed to ionizing radiation.

Badge Holder

• The plastic holder contains a system of filters to enable the dosimeter reader to determine the type of radiation the badge was exposed to, and under what circumstances.

Wearing the Dosimeter Correctly

• The dosimeter must be worn at the collar level OUTSIDE the protective apron.

Double Badges

• Staff performing interventional CT or pregnant staff will be assigned a second dosimeter.

• The second badge is to be worn at the waist, UNDER the protective apron.

• The badge holders will be coded, do not switch badges.

Care of Your Badge

• Film is damaged by heat, water, light and radiation.

• When not in use, store your badge in a cool, dry place, away from any sources of radiation.

• Do not bring your badge home!

A good place to store your badge when not wearing it – a badge rack outside the x-ray suite.

Lost or Damaged Badges

• Report any of the following IMMEDIATELY to Radiation Safety (Physicist):– Lost dosimeters.– Damaged dosimeters.– Dosimeters that have received a high dose of

radiation.

What Dose Did You Receive?

• Under normal circumstances, Your physicist should report to you if your quarterly dose exceeds Level 1. If you do not receive a report, your dose is below ALARA.

• You may contact your physicist at any time if you wish to learn the results of film badge monitoring.

Guess how this happened?

Pregnant Workers

Pregnant Workers

  Pregnant Workers should be limited to

  500 mRem/9 months.

  Extra radiation badges to wear at the waist

  are available to pregnant radiation workers.

Time, Distance Shielding

• Time: If involved in an interventional procedure, make sure the radiologist knows the total exposure time.

• The less time exposed to radiation, the smaller the dose, all other factors being the same.

Distance

• Distance - stand as far away from the patient during fluoro as feasible . When not actually assisting, stand in the control booth.

Shielding

• Shielding – stand completely behind the control booth lead wall during x-ray exposures

• All workers in the x-ray room during

studies must have a lead apron. • Keep the lead between you and

the x-ray tube.  That is, do not

turn your unshielded back to

the x-ray machine.

Thyroid Shielding

• Use of a thyroid shield keeps worker’s

•     radiation dose ALARA [as low as

•    reasonably achievable.]

• Those persons who are within three feet of the patient during a fluoroscopy study should be wearing a thyroid shield.

• Ensure there is no gap between the thyroid shield and the lead apron.

Lead Aprons

• Hang aprons and shields on racks.

• Do not bend or fold lead aprons or shields.

• Folding can cause cracks and tears in

• the protective material.

• Inspect shields for evidence of damage.

CT Shielding

1.3 μGy/sec = 0.13 mrem/sec;

~4 mrem for a 30 second scan at the outer isodose boundary.

Don’t stand in an open doorway during scanning!

Signs

• For employee and public protection, locate a red warning light with the notation "X-RAY ON" or the equivalent, on the control panel and outside door which will be lit only when the X-ray tube is activated.

Signs, Continued

•Place a label bearing the radiation symbol and the words "CAUTION –Radiation Area” on or adjacent to each X-ray tube housing.

Place a label bearing the radiation symbol and the words "CAUTION –Radiation Area” on the outside door to the CT room.

Regulation

• CT Law states that “only individuals required for the radiographic procedure shall be in the radiographic room during exposures; and except for the patient, no unprotected body parts of their bodies shall be in the useful l   beam.”

Other Safety Practices

• Use approved mechanical restraining devices to hold children and other patients whenever possible. 

• If someone must assist by holding the patient, ask an adult family member to help.

• In emergencies, CT Law allows RTs to hold patients.  If you hold  a patient, wear a lead apron and gloves. Keep out of the primary beam.  Direct the x-ray tube away from you.

Radiation Safety is Not The ONLY Safety in the CT Lab

• 1. Keep objects out of walkways.

• 2. Do not store items on overhead shelves if there is a risk of falling.

• 3. Know where the fire alarm is.

• 4. Know where the nearest exit is.

• 5. Know where all emergency shutoffs are.

• 6. Post all emergency numbers.