Monday, September 30, 2013

Radiation Safety and Guidelines During MBS / VFSS for SLPs and Patients

Hi friends,

I have had some awesome student interns lately.  Each of them completes a student project of some kind.  some of them are so awesome, I have decided to ask the students' permission and post some of them on the blog.  Here is the first of many-- a project by Amelia Bergmann.
Image source: http://lc19.blogspot.com/2010/06/meet-readi-cat-worse-than-drinking.html

The story:
We have had several issues lately regarding confusion about how much radiation is too much, how many frames per second is safe, etc.  Some of the techs in radiology are hesitant to film the studies at 25 frames per second or more, but we feel we can not make adequate measures and judgment calls with anything less.  The alternative with our machines is 12.5 frames/second!  Just terrible.  Jeri Logemann said anything less than 30 is abysmal.  How can we convince the techs that this is not that much more, and is safe for them and the patients (and is it??)?  We didn't really understand ourselves some of the ins and outs of radiation/fluoroscopy safety.  I put this issue on my to do list and my student project list in case anyone was interested, and Amelia took me up on it. She completed this Powerpoint presentation about Fluoroscopy.  I thought she did a fantastic job!  Some of the guidelines are specific to our hospital , so you would have to research your own hospital's guidelines.  Some of the questions Amelia investigated included:
  • An MBS/VFSS exam is equivalent to how many hours in the sun?
  • How much protection does the lead provide?
  • Where do SLP's need to stand in order to avoid radiation scatter during MBS/VFSS?
  • What is the pattern of the radiation scatter during the MBS/VFSS?
  • How much more radiation is the patient receiving when the frames/second are increased?  
  • What are the guidelines from pregnant patients and SLPs/therapists/techs?
  • Should we wear lead or radiation-resistant gloves and goggles during MBS/VFSS procedures? 
  • What are the radiation dose limits for SLP's and patients?
She interviewed the hospital's radiation physicist, the Radiology PA, looked up hospital and State guidelines and scoured ASHA and research articles.

So check it out!  I have pasted the slides here below.  Amelia and I hope it helps other SLPs with their questions about the mysteries of fluoroscopy.  :)
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Radiation MBS/VFSS Safety Information:

    What Is Radiation?
  • Energy in the form of particles and waves
  • Ionizing: X-rays and gamma rays
  • Some x-rays enter body and interact partially, completely, or not at all
  • Denser tissue absorbs more radiation than less dense tissue
Local Radiation Regulations (Utah):
Radiation Dosage info:
  • Radiation is all around us
  • Inverse square law (radiation received and distance from source)
  • Received through naturally occurring radionuclides (soil, food, water) and through radon indoors
  • The type of radiation emitted during fluoroscopy is not the same type of "rays" as the rays of the sun- so telling a patient that an MBS is like __ hours in the sun is not accurate.  They are not comparable. 
  • No “zero dose” of radiation exists!
                                                                                                                       (ASHA, 2004)
  • Naturally occurring: 300millirems/year
  • 300mr added from medical and man-made sources (mostly in latter years of life)    
Radiation Safety Education:
  • Education on radiation safety is not standard in graduate programs for speech pathology
  • SLP’s responsibility to be aware of guidelines, etc. to reduce radiation exposure to self and patient  
ASHA Guidelines on Radiation;
  • Guidelines for Speech-Language Pathologists Performing VFSS:
  • Principle of Ethics II Rule B: “Individuals shall engage in only those aspects of the profession that are within their competence, considering their level of education, training, and experience” (ASHA, 2003). Furthermore, individuals should consult state licensure laws regarding speech-language pathologists (SLPs) utilizing the VFSS in their particular state.
Average VFSS/MBS Radiation Exposure:,
  • Average: 1 millisievert
  • Exposed to 50 millisieverts in first 17 years of life
  • Low dose and low risk procedure
  • Little radiation exposure and dose = no risk when compared to medical benefit
  • Reducing exposure
1) Time that fluoroscopy is on
2) Distance from the source and patient
3) Shielding
Fluoroscopy time during a study:
  • Should not exceed 5 minutes (if possible)
  • Less time spent in fluoro = less radiation exposure
C Arm:
  • The arm is the source of radiation to patient 
Scatter:
  • Radiation emitted from the patient (not the direct beam)
  • Radiation hits the patient’s tissue, interacts and then changes direction
  • Decreased by a factor of 1,000 for every 1 meter in distance
                                                      (P. Jenkins, personal communication, August 13, 2013

  • Distance from the beam
  • Distance of 6 feet or more from patient:
  • Exposure due to scatter and leakage radiation from x-ray tube is so small that wearing apron does not add much protection
                                                                                        (X-ray Radiation Protection Manual, 2010
  • SLP can move to the side of the image intensifier, behind radiologist

Fluroscopy Collimation:
  • The radiation beam can be collimated to reduce scatter and enhance the contrast of the image
  • If radiologist or tech does not collimate, request it                                                                                                        (Kelchner, 2004)
  • Collimators can help change the shape (round, square) and size (large, small) of the beam                           
Panning:
  • A/P view of espohageal phase of swallow
  • Increases amount of radiation given off
  • Should be kept to minimum
  • No need for clinician to be close to patient
  • Stay back or step behind the secondary barrier                                                                                      (Kelchner, 2004)
  • More radiation required to go through thicker abdominal tissue vs. pharynx, more scatter produced                                                                       (Hayes et al, 2009)
FDA: Radiation Risks:
  • Radiation burns and/or radiation-induced cancer
  • Probability = very small
  •  Radiation risk is usually far less than other risks not associated with radiation, such as anesthesia or sedation, or risks from the treatment itself.
  • Fluoroscopy should always be performed with the lowest acceptable exposure for the shortest time necessary
UofU Hospital Guidelines:
  • Part of Utah Administration Code R313-15-201
  • Occupational dose limit for adults: 5 rem/year (5,000 millirem)
  • Non-occupational dose limit (members of the public and non-radiation workers): 0.1 rem/year
  • Pregnant worker dose limit: 0.5 rem/9 months
                                                                                     (X-ray Radiation Protection Manual, 2010)
  • 1 rem = 1,000 millirems (10 millisieverts)
ALARA: As Low as Reasonably Achievable:
  • Risk-benefit approach
  • Considers amount of exposure + need for exposure
  • If a pt’s radiation exposure is below the limit, should they receive radiation?
  • Depends on the need/benefit of the exposure                                                                                (X-ray Radiation Protection Manual, 2010)
                                -Professional risk and benefit weighed differently than patient risk and benefit
                                -No radiation dose limit for patients (MD decides)                                    
                                       (P. Jenkins, personal communication, August 13, 2013)
                                                                                               
Dosimeter badges:
  • Utah Division of Radiation Control regulations   
  • Requires only those who have a reasonable chance of exceeding 10% of the annual occupational exposure limit (5000 millirem) or those who operate a fluoroscopic x-ray unit
  • Worn on collar (or waist or finger, if issued)
  • Best legal proof for radiation exposure at work
  • Make sure that all radiation exposure is recorded (esp. unanticipated exposure!)
  • Good for radiation protection program
  • Fee for lost, damaged or “late” badges
  • Individual dosimetry report can be requested at any time
                                                                                             (X-ray Radiation Protection Manual, 2010)











Wearing Lead:
  • Leads are checked at least once/year
  • Not truly lead, but rubber material with some copper and lead interspersed
  • 1/2mm of lead-like material = min protection
  • 1 lead apron will block 95% of primary beam
  • 1 lead apron will block 99% of scatter
  • Different organs respond to radiation differently
  • Limits:
Head and torso: 5,000mr/year
Eyes: 15,000mr/year
Extremities: 50,000mr/year

Reducing Radiation Exposure
  • Know rationale for conducting a study (or repeating one)
  • Investigating the appropriateness of referrals ensures that fluoroscopy time is necessary
  • Rotating SLPs who do VFSS
  • Use FEES when possible if multiple studies will be needed
                                                                                                                     (Kelchner, 2004)
Pregnancy and Radiation Exposure
  • National Council on Radiation Protection-no. 116 requirements:
  • Dose shall not exceed 5mSv to the fetus during 9 months (0.5 mSv per month)
                                                                                          (X-ray Radiation Protection Manual, 2010)
  • 1 millisievert = 0.1 rem
  • Limited involvement with close sources of radiation, to the extent practical
  • Work in protected areas or wear protective clothing when radiation present
  • Wear additional pregnancy dosimeter at waist level (worn under apron)
  • Monthly update with DRP
                                                                                           (X-ray Radiation Protection Manual, 2010)
  • No justification to wear 2 lead aprons
  • If concerned, get thicker lead apron, but this is not really necessary
  • Can’t refuse to do radiation-related activities if under radiation limit
                                                                        (P. Jenkins, personal communication, August 13, 2013)

References:
American Speech and Hearing Association. http://www.ASHA.org
“Fluoroscopy Radiation and Safety Training Manual” (n.d.). https://www.case.edu/ehs/Training/RadSafety/fluoro.htm
Hayes et al. (2009). Radiation safety for the speech-language pathologist. Dysphagia, 24: 274-279.
Health Physics Society (2013). Answer to question #10592 submitted to “ask the experts.” https://hps.org/publicinformation/ate/q10592.html
Kelchner, L.N. (2004). Radiation safety during the videofluoroscopic swallow study: The adult exam. Swallowing and Swallowing Disorders, 24-28.
“Radiation Emitting Products” (n.d.) http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/MedicalX-Rays/ucm115354.htm
X-Ray Radiation Protection for Diagnostic X-ray use at the University of Utah Hospitals and Clinics (2010).

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That's it folks- was it helpful to some of you in the medical setting?  Let me know if you have any more info to add!  You can also comment if you have questions and I can try to find the answers and also email them to Amelia.

Kristin

(Note:  I was having some serious trouble with formatting and inserting pictures into this post.  I am aware of some of the inconsistencies in the formatting.  I don't seem to be able to fix it.  Need to take an HTML course I suppose.  :) )

3 comments:

  1. Googling and found this so helpful. Thanks Kristin! ~Kassi

    ReplyDelete
  2. Thanks! Is this the Kassi I know??

    ReplyDelete
  3. My mom had a swallow study done with this. Never said another word afterwards. Hospital won't answer questions or send a copy of radiation exposure. Don't know who signed off for the procedure as I am her legal guardian. Was to be on her way home from the hospital and I got a call at 2pm telling me they did this. Nurse was very rude.

    ReplyDelete