Translated English of Chinese Standard: YY0831-2011 www.chinesestandard.net Email: Sales@ChineseStandard.net ICS 11.040.50 YY C 43 PHARMACEUTICAL INDUSTRY STANDARD OF THE PEOPLE S REPUBLIC OF CHINA YY 0831.1-2011 Stereotactic radiotherapy system with gamma beam Part 1: Multi-source stereotactic radiotherapy system with gamma beam for head lesion γ 射束立体定向放射治疗系统第 1 部分 : 头部多源 γ 射束立体定向放射治疗系统 Issued on: December 31, 2011 Implemented on: June 1, 2013 Issued by: State Food and Drug Administration www.chinesestandard.net Page 1 of 16
Table of Contents Foreword... 3 1 Scope... 4 2 Normative references... 4 3 Terms and definitions... 5 4 Requirements... 5 5 Test methods... 8 Annex A (Informative) Materials, structure and size of special spherical die body and special focus measuring tools for test... 15 www.chinesestandard.net Page 2 of 16
Foreword All technical contents of this Part are mandatory. YY 0831 is consisted of 2 parts as follows: Part 1: Multi-source stereotactic radiotherapy system with gamma beam for head lesion; Part 2: Multi-source stereotactic radiotherapy system with gamma beam for body lesion. This Part is part 1 of YY 0831. This Part is drafted according to the rules specified in GB/T 1.1-2009. Please note that some contents in this Document may involve patents. The issuing authority of this Document does not undertake the responsibilities to identify these patents. The part was proposed by China Food and Drug Administration. The part shall be under the jurisdiction of National Standardization Technical Committee of Medical Appliances Radiotherapy and Technical Committee of Nuclear Medicine and Radiation Dosimetry Equipment (SAC/TC10/SC3). Drafting organization of this Part: Beijing Institute of Medical Device Testing, Shenzhen Haibo Technology Co., Ltd., Medical Science & Technology Development (Shenzhen) Co., Ltd. (MASEP), Shenzhen Shengai Medical Technology Development Co., Ltd., and Shenzhen Zunrui Technology Co., Ltd. The main drafters of the part: Zhang Zhaoyuan, Zhang Xin, Song Lianyou, Chen Jing, Zhu Weiqun, Xu Tao, Zheng Tie, and Liu Guangwu. www.chinesestandard.net Page 3 of 16
Stereotactic radiotherapy system with gamma beam Part 1: Multi-source stereotactic radiotherapy system with gamma beam for head lesion 1 Scope This Part of YY 0831 specifies the scope, terms, definitions, requirements, and test methods of the multi-source stereotactic radiotherapy system with gamma beam for head lesion. This Part applies to the multi-source stereotactic radiotherapy system with gamma beam for head lesion (hereinafter referred to as the system). The system simultaneously uses multiple 60 Co sealed radioactive sources (it may be dynamic or static) to conduct beaming irradiation to the head lesion. 2 Normative references The articles contained in the following documents have become part of this Document when they are quoted herein. For the dated documents so quoted, all the modifications (Including all corrections) or revisions made thereafter shall be applicable to this Document. GB 9706.1-2007 Medical electrical equipment - Part 1: General requirements for safety GB 9706.15-2008 Medical electrical equipment - Part 1: General requirements for safety - Collateral standard: Safety requirements for medical electrical systems GB 9706.17-2009 Medical electrical equipment - Part 2: Particular requirements for the safety of gamma beam therapy equipment GB/T 17857-1999 Medical radiology Terminology (Equipment for radiotherapy, nuclear medicine and radiation dosimetry) GB/T 18987-2003 Radiotherapy equipment - Coordinates, movements and scales YY 0637-2012 Medical electrical equipment - Requirements for the safety of radiotherapy therapeutic planning systems www.chinesestandard.net Page 4 of 16
c) For the focused field of which the nominal size is greater than 20 mm and less than or equal to 30 mm, the dose gradient of each focused field shall not exceed 10 mm. 4.6 Deviation of positioning reference point Deviation of the positioning reference point of the system shall meet the following requirements: a) For the minimum focused field, the deviation between the positioning reference point and the focus shall be less than or equal to 0.5 mm; b) The deviations of positioning reference point for each focused field shall be included in accompanying documents. 4.7 Integrated error of dose calculation For each focused field, the error between the absorbent dose value calculated by the therapeutic planning software AND the actual measured value shall not exceed ±5%. 4.8 Position error of therapeutic plan reference point Reconstruction position error of therapeutic planning software shall not exceed 1.5 mm. 4.9 Safety requirements The system shall meet the requirements of GB 9706.1-2007, GB 9706.15-2008, GB 9706.17-2009 and YY 0637-2012. 5 Test methods 5.1 Coordinate system Check the accompanying documents. It shall comply with the requirements of 4.1. 5.2 Accompanying documents Check the accompanying documents. It shall comply with the requirements of 4.2. 5.3 Nominal absorbed dose rate of the focus 5.3.1 The ionization chamber and the dosimeter used for measurement shall meet the requirements of the measurement conditions. Install the special spherical die body (hereinafter referred to as "Special Die body", see Appendix A) of which the diameter is 160 mm on the positioning bracket. The die body s center is located at the positioning reference point. Insert it into ionization chamber, so as to make its effective measurement point to coincide with the die body s center. Transfer the special die body along with the therapeutic bed into a predetermined irradiation position. Use the maximum focused field. www.chinesestandard.net Page 8 of 16
minimum focused field; Dmax Dosimeter readings at the focus in special spherical die body when using the maximum focused field. 5.4 Focused field size 5.4.1 Grayscale-dose calibration Radiate a series of films in the allowed test area of grayscale-dose response curve of the film. Use a suitable mathematical model according to the radiating dose values and the corresponding film s grayscale value, Draw the grayscale-dose response curve for the radiation films used. 5.4.2 Focused field film radiation According to following steps to respectively measure the maximum deviations of the focused field size and the nominal value: a) Select a set of collimator for therapy. Measure at least on 2 focal planes; b) Put the film of which the size fits the measurement of focused field onto the central position of special die body. Let the film to be located on some focal plane; c) Transfer the special die body, together with the therapeutic bed, into focus position. Start to radiate. Radiation dose shall be within the appropriate response area of the grayscale-dose response curve of the film used. d) Repeat b). Let the film to be located on another focal plane. Repeat the radiation operation of c); e) Replace the collimator. Repeat tests b)-e). Complete the radiation of each group of focused field; f) Perform the therapy to the film. 5.4.3 Calculation of focused field size According to following steps to calculate the focused field size: a) Use a scanner to scan the film. The resolution shall not be less than 300 DPI. Respectively scan the focused field films of 5.4.2; b) Use the grayscale-dose response curve of 5.4.1 to convert the film grayscale TO corresponding dose values. Draw a dose distribution curve on directions of 3 axes. c) Separately find out the dose of each film at positioning reference point. Define the dose value as the 100% dose value of the film; www.chinesestandard.net Page 10 of 16
planning software AND the actual measured absorbed dose value shall comply with the requirements of 4.7. Calculate the absorbed doses at 3 reference points. Calculate the relative deviation according to Formula (6); Where: ΔP Relative deviation between focus planned dose and measured dose, %; P0 Planned dose at die body center (i.e., focused plan dose), in unit of Gy; P1 Actual measured absorbed dose at die body center, in unit of Gy. 5.8 Position deviation of therapeutic planning reference point According to the image parameter s requirements that are given by accompanying documents and are required to achieve the reconstruction precision of three-dimensional image of therapeutic planning software, fix the imaged head die body that is installed with 3 known target volumes INTO the stereotaxic positioning apparatus. Mount together on an imaging system to scan, so as to obtain satisfactory image. Input the image data into therapeutic planning system. Calculate the coordinates of the 3 target volumes. Respectively calculate the position coordinates of the center of the 3 target volumes in the 3 directions of X, Y, Z. Calculate the reconstruction position deviation of the three-dimensional image of therapeutic planning software according to Formula (7): Where: Δ2 The distance between the center of the target volume and reconstruction target volume of therapeutic planning software, in unit of mm (mm); ΔX2 In X-axis direction, the distance between the center of the target volume and reconstruction target volume of therapeutic planning software, in unit of millimeter (mm); ΔY2 In Y-axis direction, the distance between the center of the target volume and reconstruction target volume of therapeutic planning software, in unit of millimeter (mm); ΔZ2 In Z-axis direction, the distance between the center of the target volume and reconstruction target volume of therapeutic planning software, in unit of www.chinesestandard.net Page 13 of 16
millimeter (mm). Check the accompanying documents. The maximum deviation s calculation results of reconstruction position of the center of the three target volumes shall comply with the requirements of 4.8. At the same time, it shall report ΔX2, ΔY2, ΔZ2. 5.9 Safety requirements Implement it according to the methods specified in GB 9706.1-2007, GB 9706.15-2008, GB 9706.17-2009, and YY 0637-2012. www.chinesestandard.net Page 14 of 16