This is an important document, targeted to an area that has only been highlighted to a minor degree in the past. Being a part of a regulatory and auditing body, I’m aware of the problems with lack of competence and often also bad attitudes towards radiation protection, especially outside the radiological departments. We have also documented this in an article (doi: 10.1093/rpd/ncr304). Specific comments Line 569, table 2.2: The threshold values of tissue reactions during fractionated exposure of the lens are a bit unclear. The threshold dose for detectable opacity is higher then for cataract in the table. Line 774: Suggest a new sentence. “When using over couch geometry, fingers in the primary beam will typically receive doses that are 100 times higher in comparison when using under couch geometry.” Line 813: Suggest a new sentence. “In addition to the greater thickness, the source to skin distance will decrease giving an additional increase of the skin dose.” Line 861: Suggest a new sentence. “The scatter will increase linear with the increase of the area of the radiation field. A poor collimated primary beam, which is partly outside the patient, will further increase the staff doses since there is no tissue to attenuate the scatter.” Line 994: Suggest a new sentence. “The dosimeter above the apron shall be worn on the collar closest to the X-ray tube, usually the left collar. This will give an indication of the lens dose.” Line 2421: Is it the relative risk of incidence of childhood cancer that is mentioned on line 2421? Later on line 2423 is it mentioned the risk of fatal childhood cancer. Best regards Anders Widmark ___________________ Anders Widmark Senior advicer Norwegian Radiation Protection Authority Section for Dosimetry and Medical Applications -------------------------------- Associate Professor Gjøvik University College