Re: Radiation monitoring badges in cine/floro exams

["Dept of Radiography, Canterbury Christ Church College" <c.d.jeffery@canterbury.ac.uk>]

> 
> What is the recommended practice for the monitoring of workers who are exposed 
> to radiation from cardiac cath. procedures such as cineradiography and 
> fluoroscopy.  I have seen film badges on left upper arms outside lead vest and 
> inside the lead vest in the chest region as well as at the neck above the lead 
> vest. 

I'm never convinced about the arguments which suggest the position should be such as to record the 
highest received doses. The dosemeter should record an indication of the whole body dose and as such 
should be worn at chest or waist height. In fluoroscopy examinations, when a lead apron is worn, the 
dosemeter then should clearly be under the lead. 

This thinking is reinforced in the  Guidance Notes for the Protection of Persons Against Ionising 
Radiations Arising From Medical and Dental Use (NRPB, UK 1988). Chapter 1 paragraph 21 states:

 "If a person is wearing a protective apron then in addition to a dosemeter worn under the apron, one or 
more dosemeters should be worn on unprotected parts of the body if there are likely to be 
contributions greater than 1/10 of the effective dose equivalent from their exposure"  

The regular dosemeter should always be worn under the apron where it monitors dose to the trunk and 
so to organs with the larger weighting factors. If dose rate in the environment is high, such as in the 
region of the cath lab table additional dosemeters should be worn outside the apron. The exact position 
of additional dosemeters , on the collar, sleeve or nailed to the forehead is probably immaterial, but 
should be standardised locally.

Chris Jeffery
Senior Lecturer in Radiation Science
Department of Radiography
Canterbury Christ Church College  UK

c.d.jeffery@cant.ac.uk