Not so easy to answer. The aim is to minimise exposure and the typical annual limit for radiation dose is 20mSv which is still low. The idea is that you avoid exposure to ionizing radiation

Since 1990, a number of studies of radiologists have been published that utilized measurements of individual exposure (Andersson and others 1991). Andersson and colleagues (1991) studied the cancer risk among staff at two radiotherapy departments in Denmark. The average cumulative radiation dose was 18.4 mSv, although 63% of the persons had doses <5 mSv. The expected number of cancers was estimated using cancer incidence rates from the Danish Cancer Registry. The overall relative risk was 1.07 (95% CI 0.91, 1.25) for all cancers, and no significant dose-response was observed. The risks for cancers that are considered radiation sensitive were not elevated.

Andersson, M., G. Engholm, K. Ennow, K.A. Jessen, and H.H. Storm. 1991. Cancer risk among staff at two radiotherapy departments in Denmark. Brit J Radiol 64:455-460.

Berrington and colleagues (2001) reported the results of 100 years of follow-up of British radiologists who registered with a radiological society between 1897 and 1979 and who were followed until January 1, 1997. A progressive increase was observed in the SMRs for cancer with number of years since first registration. It appears that excess risk of cancer mortality in the period more than 40 years after first registration is likely a long-term effect of radiation exposure for radiologists registering between 1921 and 1954. Radiologists whose first registration was after 1954 demonstrated no increase in cancer mortality, possibly because of their lower overall radiation exposure.

Berrington, A., S.C. Darby, H.A. Weiss, and R. Doll. 2001. 100 years of observation on British radiologists: mortality from cancer and other causes 1897-1997. Brit J Radiol 74:507-519.