[Dysphagia] Fluoro time and instructions

[pleslie at pitt.edu (Leslie, Paula)]

Hi Sharon
 
The crucial thing is not how long but how high a dose and that is dependant on several factors.  And the screening should rarely be allowed to run on whilst nothing is happening.  As if by magic I can pull out a paper published in Dysphagia that might help from my top hat here (and a white rabbit on a good day):

Radiation Dose in Videofluoroscopic Swallow Studies.


*	Zammit-Maempel I <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Search&itool=pubmed_AbstractPlus&term=%22Zammit%2DMaempel+I%22%5BAuthor%5D> , Chapple CL <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Search&itool=pubmed_AbstractPlus&term=%22Chapple+CL%22%5BAuthor%5D> , Leslie P <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Search&itool=pubmed_AbstractPlus&term=%22Leslie+P%22%5BAuthor%5D> . 

Department of Clinical Radiology, Freeman Hospital, High Heaton, Newcastle upon Tyne, NE7 7DN, UK.

Videofluoroscopy has become an increasingly important armament in the investigation and assessment of swallowing disorders. However, very little work has been published on the radiation dose used in such examinations and currently there is no national diagnostic reference level in the United Kingdom. Videofluoroscopy in our hospital is performed predominantly by one radiologist (IZM) in a single fluoroscopy room. We recorded the screening times of 230 patients over a 45-month period. Screening time ranged from 18 to 564 s (median = 171 s) associated with a median dose-area product of 1.4 Gy cm(2). This is below the third quartile level of 2.7 Gy cm(2) for all such examinations performed across the northern England. The effective dose associated with a typical videofluoroscopy dose-area product is 0.2 mSv. Videofluoroscopy is the most appropriate instrumental examination for assessing oropharyngeal swallow biomechanics and intervention strategies. This data set is based on the largest number of videofluoroscopy swallow studies published to date. Our results show that videofluoroscopy can be performed using minimal radiation doses.

 
We wrote it precisely to give SLT/Ps some evidence to help argue for the service and to counter the "VF uses massive doses" argument.
 
11 minutes is pushing the system to be honest though in an 80+ year old who kept moving about, I think we once got about 7 minutes.   And if there's a 30 year lag time between exposure and possible radiological problem then it's not really going to be that great a risk.  This is an extreme example.  Read the paper, think about the factors we talk about, check with the med physics (or whoever checks dosages at you place) then make a decision on more than just the time factor.
 
As to holding a bolus and waiting for the command well sometimes it is useful to see what oral control is like, or to get the screening lined up for an awkward shot.  I'd never say never, but most of my patients would have no idea what I'd asked them to do!
 
Paula
 
Paula Leslie
CertMRCSLT
Associate Professor, Communication Science and Disorders
Specialist Advisor (Swallowing Disorders) RCSLT
University of Pittsburgh
4033 Forbes Tower
Pittsburgh, PA  15260
tel: (+1) 412- 383-6748     fax: (+1) 412-383-6555
pleslie at pitt.edu <mailto:pleslie at pitt.edu> 
http://www.shrs.pitt.edu <http://www.shrs.pitt.edu/> 
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________________________________

From: dysphagia-bounces at b9.com on behalf of Sharon Manders
Sent: Thu 1/18/2007 16:56
To: dysphagia at b9.com
Subject: [Dysphagia] Fluoro time and instructions



Hi,

Does anyone know if there is a maximum fluoro time that is acceptable for an
MBS? Our old machine had an alarm that would ring after 5 minutes. One of
our SLPs had a patient last week and the fluoro time was 11 minutes which
the Head Rad said was unacceptable and more than double what she would
consider the maximum. Can anyone point me to anything with a number or a
range?

Also, how many people instruct the patient not to swallow until they (the
SLP) have moved away from the beam (and does it work)?  Obviously not all of
our patients would be able to follow this instruction. I just want an idea
as we are having a lot of problems lately in Diagnostic Imaging. Any
thoughts and ideas are welcome.

Thanks,

Sharon
--
"Death is caused by swallowing small amounts of saliva over a long period of
time."
- George Carlin
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