X-ray Radiation Safety Course. James Kane & Rob Deters Office of Radiological Control

Transcription

1 X-ray Radiation Safety Course James Kane & Rob Deters Office of Radiological Control

2 About the Course X-ray Radiation Safety X-ray radiation safety training is mandatory for radiation workers to comply with State Regulatory requirements and current University policies. Individuals requiring this training include, but are not limited to, Nurses, Technical Support Staff, Technicians and Students. You should allow about 1 hour to complete this course. Course Test To receive credit for this course you will be expected to successfully complete a short test after reviewing the training information.

3 Course Objectives This training course will review: Radiation Standards and Oversight Maximum Permissible Dose limits Radiation Hazards Personal Dosimetry Radiation Protection Equipment and Procedures Emergency Procedures To begin with, let s review how x-ray radiation is regulated

4 Radiation Standards and Oversight The Illinois Emergency Management Agency, Division of Nuclear Safety (IDNS) regulates and inspects SIU facilities to ensure the safe possession and use of radiation-producing devices, such as x-ray machines. State regulations for facilities possessing x-ray producing equipment are: Ill. Administrative Code, Part 360: Use of X-rays in the Healing Arts Including Medical, Dental,Podiatry, and Veterinary Medicine

5 Radiation Safety Program SIU Radiation Safety Program The goal of the SIU Radiation Safety Program is to provide guidance for the safe use of radiation producing equipment in the University s clinical and research areas and for the safety of all personnel involved. The University s Radiation Safety Officer (RSO) oversees this program. Visit the SIU Office of Radiological Control website for additional radiation safety and guidance documents at:

6 Who Is Permitted to Use Fluoro Equipment? Who May Use Fluoroscopy Equipment? IDNS regulations state that fluoroscope equipment can be used only by a licensed practitioner or an accredited medical radiographer under the supervision of a licensed practitioner. What is a licensed practitioner? IDNS regulations defines a licensed practitioner as a person licensed to practice in the treatment of human ailments under the Medical, Dental, and Podiatric Practice Act.

7 Prohibited Use of Fluoro Equipment It is unlawful to operate any x-ray equipment unless it is operated in compliance with all provisions of regulations. The use of x-ray radiation on humans is strictly regulated and is only permitted with authorization from a licensed practitioner for healing arts purposes. Individuals can not be exposed to x-ray radiation for training or demonstration purposes. Now, let s review occupational radiation exposure limits and hazards

8 Occupational Exposures Occupational exposure is the radiation exposure you may receive working with and around x-ray systems as part of your work. Federal, State and University regulations limit the amount of radiation dose allowed for occupational radiation workers, members of the public, and the fetus of a declared pregnant radiation worker. In 1895, while doing work on the recently discovered cathode ray, William Roentgen identified an unknown invisible ray that he called an X ray. Within one year of their discovery, documented injuries from exposure to X-rays were recorded.

9 Occupational Dose Limits All SIU personnel that work with any form of radiation are considered radiation workers and are subject to occupational dose limits. These limits do not include background radiation or radiation received for personal medical reasons. Maximum Permissible Dose Adults Whole Body Head, Neck, Torso, Upper arms & legs Lens of the Eye Extremities, Skin, and Internal Organs 5,000 mrem 15,000 mrem 50,000 mrem Doses received within these limits are not expected to cause adverse health effects even if the maximum is received each year for a total of fifty years

10 Prenatal Radiation Exposure A Declared Pregnant radiation worker is a woman who has voluntarily chosen to declare her pregnancy in writing to the Radiation Safety Officer. The maximum permissible dose limit to an embryo/fetus of a declared pregnant radiation worker is 500 mrem for the entire pregnancy.

11 Why is Radiation Harmful? Radiation can cause changes in human cells and tissues by interfering with the way a cell functions Damage to cells may cause mutations and cancer Similar effects may occur from chemicals However, most damage caused by these changes in cells is usually seen in people who have received very high doses of radiation in a very short amount of time

12 Radiation Exposure Current radiation safety practices are focused on keeping your occupational exposure to radiation as low as reasonably achievable. However, the radiation exposure you might receive while working with X-ray equipment is only a fraction of your total radiation exposure! Radiation is everywhere. You are constantly being exposed to ionizing radiation from many sources. Typically, your greatest source of radiation exposure comes from nature itself. This is called background radiation.

13 Sources of Background Radiation Natural = 300 mrem Radon basements and water supplies Cosmic outer space Terrestrial soil, rocks and plants Human-produced = 60 mrem Medical and dental x-rays 200 million medical x-ray s performed each year Nuclear medicine and cancer therapy 15 million cancer therapy treatments each year Consumer products TV s, smoke detectors, tobacco products, natural gas, etc. Average person receives 360 mrem per year

14 ALARA ALARA stands for as low as reasonably achievable. IDNS regulations require that you make every reasonable effort to maintain your radiation exposure as far below the maximum allowable permissible dose limits as practical taking into consideration the purpose for which sources of radiation are used. All individuals can implement ALARA by limiting their time near x-ray sources, being aware of the location and intensity of scatter radiation, and utilizing shielding whenever possible (and as required).

15 ALARA The radiation exposure for occupational workers is a lot less than the annual radiation exposure limits because personnel follow ALARA guidelines. The basic guidelines are: Minimize your time near radiation sources. Maximize your distance from radiation sources. Use shielding devices when applicable. Patient radiation exposure must also be ALARA, this includes: Collimation of the primary radiation beam. Understanding the controls of the equipment to lower patient dose when possible.

16 Time Radiation dose is directly proportional to the TIME an individual is exposed to a source of ionizing radiation. When possible, fluoro beam-on time should be minimized for the benefit of both the patient and staff. Minimize beam-on time by using intermittent, rather than continuous, fluoro. Operators and assistants should always work quickly and spend as little time as possible next to x-ray equipment while it is operating. Additionally, use digital storage and image hold functions when available.

17 Distance The more DISTANCE you put between yourself and a radiation source, the less exposure you receive. When possible, increase your distance from the patient during fluoroscopy. This is called the inverse square law. For example, simply taking two steps backward from the patient you will decrease your radiation exposure by a factor of four. Taking three steps backward from the patient will decrease your radiation exposure by a factor of nine. Take a step back whenever possible!

18 Shielding The application of SHIELDING provides a barrier between you and the source of radiation Personnel involved in fluoroscopic x-ray procedures can reduce their radiation dose by wearing lead aprons All personnel in the room during a fluoroscopic procedure must wear a lead apron and their dosimeter Wear a lead apron! Other shields include thyroid shields and lead glasses Let s take a look at personal monitoring and badge reports

19 Dosimetry Badges Dosimetry Badges are intended to measure your external occupational radiation exposure received while working at SIU. A new badge is issued to you each month. Your dosimetry history is available from the RSO by written request.

20 Dosimetry Badge Guidelines If you are issued a dosimetry badge follow these guidelines. Your badge is your responsibility and all readings are permanently recorded in your dosimetry history. Wear only the badge assigned to you Do not wear your badge while participating in personal medical/dental procedures Never intentionally expose your badge or anyone else s badge to radiation Never take your badge home. Store your badge in the designated area If your badge is lost or damaged call the RSO immediately for a replacement

21 Wearing Your Dosimeter Always make sure your dosimeter is worn on the collar external to your lead apron and thyroid shield. Wearing your dosimeter incorrectly can result in false dose measurements.

22 Dosimetry Reports Monthly Dosimeter Report On Landauer dosimeter reports, you are identified by your participant number (found on the back of your dosimeter). Dosimeter reports are sent to your department each month. If you are unable to locate any report, contact the RSO at SL Selected Minimum Reporting Limit Whole body doses equivalents of less than 10 mrem will be noted as SL for minimal on the dosimeter report. M for ring dosimeters is less than 30 mrem. ALARA Action Levels If any dose equivalent exceeds a pre-established ALARA action level, the RSO contacts the participant and his/her supervisor to determine if future exposure can be reduced.

23 Dosimetry Reports What do Deep, Eye and Shallow indicate on Dosimeter Reports? Deep Dose equivalents in the Deep column heading mean penetrating radiation dose to internal organs. Eye Dose equivalents in the Eye column heading indicate dose to the lens of the eye. Shallow Dose equivalents in the Shallow column heading means dose to the skin for whole body dosimeters. For ring or extremity dosimeters this exposure signifies an exposure to the fingers, hands, and lower arm.

24 The Early Years Medical uses of x-rays in 1899 An x-ray system from the pioneering days. Patients had to hold the film cassettes themselves.

25 Image Intensifier and the X-ray Tube The image intensifier screen absorbs most of the radiation that passes through the patient. Remember The x-ray beam does not emanate from the image intensifier! It originates in the X-ray tube. X-ray Tube

26 Fluoroscopy and Scattered Radiation Fluoroscopy procedures are responsible for the highest occupational exposure at SIU Scattered Radiation Is that part of the x-ray beam which bounces off the patient (and also other material in the x-ray beam), and can reach the operator and medical staff. The patient and procedure table are the main source of scatter radiation during radiographic and fluoroscopic procedures. Significant exposures are possible in the absence of shielding between medical personnel and the patient or table. In general, the more radiation the patient receives, the more the operator and others present could also receive.

27 More on Scatter Radiation During image formation, scatter radiation exposure is present within a six foot radius of the patient. Scatter reduces very quickly as the distance from the patient increases. Remember, scatter radiation goes in all directions from the patient Now, let s review protection procedures

28 Protective Apparel Fluoroscopy Procedures ALL staff, present during fluoro procedures are required to wear lead aprons. Aprons are necessary because many fluoroscopic units do not come equipped with barriers or with builtin shielding to attenuate scattered x-rays. Other Diagnostic X-ray Procedures Protective apparel can reduce exposure to the thyroid, extremities, and eyes. Leaded aprons, thyroid shields, leaded gloves, and glasses should be available to ALL personnel involved with x-ray operations who may be exposed to direct or scattered radiation and who are not otherwise shielded. Please Note! Standing behind another individual is not considered shielding regardless of whether or not that individual is wearing a leaded apron.

29 Protective Apparel Because of the scatter radiation that is present in a room during fluoroscopy, the following is mandatory: Any individual within a six foot radius of a patient during fluoroscopy must wear a lead apron. Anyone within a three foot radius of a patient during fluoroscopy should wear a thyroid shield. There should not be a gap between your thyroid shield and lead apron.

30 Lead Aprons Lead aprons cover about 75%-80% of a person s active bone marrow. Cracked or damaged aprons are not effective shields. Handle them carefully and do not fold them. The amount of attenuation provided by a lead apron depends on its physical condition, how it is worn, its lead equivalency, and the kvp (energy) of the x-ray beam. % Percentage of radiation blocked by Aprons at selected kvp s Lead Equivalent 50 kvp 75 kvp 100 kvp.25 mm mm

31 Lead Aprons and Exposure Reduction The reduction in dose to staff during cardiology procedures is significant when lead aprons are worn. Dose to the lens of the eye may be significant when leaded safety glasses are not worn. Dose with Lead Apron Dose without Lead Apron Dose to Lens of Eye Cardiologist Nurse 9 mrem 2 mrem Per Cardiac Catheterization 160 mrem 30 mrem 60 mrem 20 mrem Cardiologist Nurse 20 mrem 8 mrem Per Angioplasty 310 mrem 60 mrem 100 mrem 50 mrem

32 Hang Lead Aprons Properly Hanging lead aprons on hangers/hooks prevents the lead from cracking. Lead aprons, thyroid shields, and lead gloves should be checked annually for cracks and/or holes.

33 Lead Aprons Not Taken Care of Properly

34 Thyroid Shields, Leaded Safety Glasses, and Gloves The use of thyroid shields, leaded safety glasses, and gloves are strongly recommended during fluoro procedures. Exposure to the thyroid or the lens of the eye can be as high as mrem per hour during some procedures. Leaded glasses may reduce the dose to the eyes from scatter radiation by about 85%. Shielding gloves should be worn if the hands are placed in the primary x-ray beam. Radiation resistant gloves attenuate direct or scattered radiation exposure 55% to 26% at 60 kv to 125 kv.

35 Portable or Mobile Shields Portable or Mobile shields of at least.25 mm lead equivalency are recommended to be used by anyone working near the table during fluoro procedures when possible. Leaded Plexiglas Shield

36 Fluoro Table Shielding Table Radiation Shielding Overlapping protective drapes or sliding panels for above and below the fluoro table can provide an additional level of protection to medical personnel from scattered radiation.

37 Holding Patients Holding Patients No individual can be asked to routinely hold a patient during x-ray procedures. An individual who volunteers, should wear 0.5 mm lead equivalent protective apparel (i.e., apron, glasses, gloves) on any portion of their body exposed to the direct beam. Protective apparel of 0.25mm lead equivalent is required for exposure to scatter radiation. Pregnant women should not hold patients during x-ray procedures.

38 Patient Exposure and Shielding Patient Exposure Regulations require that the radiation exposure to the patient must be the minimum required to produce images of good diagnostic quality. Patient Shielding During x-ray procedures in which a patient s reproductive organs are within the useful beam, gonad shielding 0.5 mm lead equivalent must be used for patients who have not passed reproductive age. The exception to this rule is in cases where shielding would interfere with the diagnostic procedure.

39 Decrease Air Gap between Image Intensifier and Patient During fluoroscopy, the image intensifier should be kept as close as possible to the patient. This will reduce radiation dose to the patient, staff, and optimize image quality.

40 Collimation of X-ray Beam The amount of scatter produced increases with the size of the area irradiated. It is good radiographic practice to restrict the field size to the area required to be imaged. This will help minimize patient and personnel exposures.

41 Warning Signs Highly visible signs assure unnecessary exposure to staff and patients.

42 Radiation Safety Reminders Use the least amount of fluoroscopy time Use proper collimation of primary beam Whenever possible maintain the greatest distance between the patient and the primary beam Keep image intensifier as close to patient as possible (decreases patient dose, personnel dose and improves image quality) Lead garments, lead gloves, thyroid shields, leaded glasses, lead drapes, and barriers between the patient and personnel all reduces exposure from scattered radiation Wear lead apron and thyroid shield, with no gap in between Wear your radiation dosimeter in its proper location: outside of the lead apron at the collar level

43 Unsafe and Emergency Conditions IF AN UNSAFE CONDITION ARISES WITH AN X-RAY DEVICE: Report any unusual or unsafe condition involving sources of radiation to the Radiation Safety Officer (RSO) at If an emergency occurs Stop work! Turn power OFF to the X-ray equipment Notify your Supervisor and contact the RSO

44 Contact for Assistance You are almost done reviewing the course material. One last item remains - who do you contact with questions and concerns? For more information regarding X-ray safety, registration, and compliance issues, contact: James Kane or Rob Deters Radiation Safety Officers [email protected] or [email protected]

45 X-ray Safety Resources For more information about x-ray protection, you may find the following resources useful. Information in these links will not be covered in the course exam. U.S. Food and Drug Administration Pacific Northwest X-ray Protective Products Kappa Medical Safety Products

46 Congratulations! You have completed the X-ray Radiation Safety Course You may now proceed to the Test A passing score of 80% is required to receive course credit. You will be asked a total of twenty (40) questions. Please read each question carefully and respond appropriately. You need to answer at least 32 questions correctly in order to successfully complete the training. Refer to the training material to assist you with answering the questions.