Vol.7 No.4 2015

Research paper : International standardization of four dimensional radiotherapy system (Y. HIRATA et al.)−238−Synthesiology - English edition Vol.7 No.4 (2015) As you indicate, the participation of a wide range of Japanese stakeholders to create the WG for international standardization strategy for 4DRT, and the creation of a standard proposal based on the comments of people from various fields, including equipment manufacturers, physicians, medical physicists, researchers, and government agencies led to the standardization of 4DRT as explained in this paper.4 Is this a product standard or a test standard?Question (Akira Ono)I ask you about the target range of the standard (or the scope of the standard) that Japan attempts to propose in the future. While it is addressed in subchapter 4.2 as well as in chapter 5 “Future direction,” which of (1) or (2) below is the target range of the standard that the authors assume? Or does it encompass both?(1) Product standard: Are you trying to specify performance or function required for 4DRT? That is, are you trying to create a “product standard” for the 4DRT equipment?(2) Test method standard: Are you trying to specify necessary items and methods to test the 4DRT? That is, are you trying to create a “test method standard” for the 4DRT equipment?As a personal opinion, if you are assuming development of a test method standard as in (2), I think you can clearly differentiate between a piece of equipment for which thorough safety considerations have been done and one that haven’t. Also, the user can clearly recognize highly safe equipment by investigating whether it matches this standard. Therefore, this standard is advantageous to the users around the world, and at the same time, I think the equipment with solidly enhanced safety will be evaluated highly.Answer (Yuichi Hirata)The specific target range of the standard in the future will encompass both (1) and (2) that you described. For (1), I think the necessary performance and functions are standardized based on the 4DRT systems that currently exist on the market. For (2), I think, for example, the evaluation test method for 4DRT using the dynamic phantom will be standardized.


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