Crew (flight & Cabin) are already subjected to enough ionising radiation during flight without additional radiation in screening. The US and EU classify them as radiation workers and they fall into the top 5% of such workers for exposure. Look
here for some information.
As their work already involves exposure any additional unnecessary (ie when you have a choice) exposure ought to be avoided. Radiation workers in other industries are educated about managing their exposure and to minimise exposure both at work and outside work. I suspect this education doesn't occur for crew. I strongly encourage crew to learn about their exposure from flight, consider other sources (like background radiation in your home town or medical procedures) and whether you can afford the risks of an ionising radiation scan.
If you work as crew on an aircraft, please educate yourself about your radiation exposure and carefully consider the APA president's advice.