after 39 treatments of IMRT for prostate ca should I be concerned about routine X rays such as chest or dental
exam X rays.

This is a simple matter of telling each doctor about the others.
Dental X-rays are very low intensity and don't really need to be mentioned.

I don't think it's your job to be concerned , your doctor should be aware of your medical history and he should be the one to tell you if the X rays are recommendable. You could also check this <a href="http://www.onradinc.com/nighthawk-radiology-alternative/">nighthawk radiology</a> resources, I found some helpful information on it when I needed it, I hope it does the same for you.

I've had 2 head CT scans: The first was in 2007, when I was 25 yrs old, and 25wks pregnant. The doctor told me he would use the lowest dose radiation possible and that there would be no harm to my baby. The 2nd was also a head CT scan, which was done in April 2012, whne I was 31 yrs old. Both scan showed that there was no abnormalities, however, after researching the effects of radiation, I'm extremely worried about the irreversible damage the radiation may have done to my body and my cells. I'm extremely worried of developing cancer from these scans. As a mother of 4 young children, at the time, the benefits out weighed the risks, but now that I know there was nothing wrong I can't help but feel the scans were all for nothing. Can you please offer any reassurance?