Comments to: Preventing Accidental Exposures from New External Beam Radiation Therapy Technologies New publication ICRP Ref.32/147/07 gives the overview on the potential radiological accidents that could occur in connection to the implementation of new technologies. The authors took into account particularly already existing classical databases of radiological events/accidents (RA) and try to find the relationship between particular RA and to generalize them. We have following comments to the concept of the document: 1. Simple list of radiological accident from different databases is not enough to bring further improving in the prevention of accident if these are not in detail analyzed and the root causes are not find 2. Different databases are not according to our opinion comparable, because the events are documented and notified in non-uniform way and thus is very difficult to perform the comparison 3. Currently as the authors mention number of already existing documents and the lessons learned from RA are accessible to all potential interested persons 4. The submitting document is one of others even if it is focused on modern treatment methods 5. Neither all methods nor aspects of modern treatment methods are in the document covered e.g. a treatment by cyberknife, tomotherapy of Leksell knife. At the same time the attention in not given to higher dose of patients due to higher number of examination methods in connection to IGRT methods. We assume that the time is mature for fundamental documents from whole world organizations or communities and should be dedicated more to theory of genesis of potential and real RA, in particular human failure causing the accident and to find the general methods and means to prevent/avoid radiological accidents. Only in general the chapter 5 mentions the possible approaches and methods to prevent radiological accident. Currently AAPM prepares for a new method of IMRT - the FMEA - a detailed analysis (failure mode and effect analysis – analysis of potential ways and consequences of failures), that could be in reality a general approach to the prevention of radiological accidents. Similar analysis for LGK is in preparation with UPC Pittsburgh. The general guide/instruction for a system and new “standard” protocols for single modern methods should be elaborated in mutual cooperation of the big organizations such as ICRP, IAEA, ICRU with closely participation of hospitals and leading medical specialists.