GB 16364-1996 Standard for radiation health protection in afterloaded gamma source brachytherapy
Some standard content:
National Standard of the People's Republic of China
Radiological protection standard for gamma-ray afterloading brachytherapy1 Subject content and scope of application
GB16364--1996
This standard specifies the protection requirements and equipment detection for afterloading brachytherapy (hereinafter referred to as "afterloading radiotherapy") equipment, radiotherapy rooms and afterloading radiotherapy.
This standard applies to the practice of brachytherapy using sealed source afterloading technology. 2 Referenced standards
GB2894 Safety signs
GB4076 General provisions for sealed radioactive sources
GB4792 Basic standards for radiological protection
GB11806 Regulations for the safe transportation of radioactive materials3 Terminology
3.1 Afterloading technology The technology of correctly placing the source applicator at the part of the patient that needs treatment in advance, and then using automatic or manual control to input the radioactive source in the source storage into the source applicator for treatment. 3.2 Afterloading brachytherapy is a radiotherapy method that uses afterloading technology to achieve a predetermined dose and distribution by allowing the radioactive source to reside in the natural cavity, duct or tissue of the human body according to clinical requirements. 3.3 Source storage container A container for storing radioactive sources for afterloading therapy. It includes a transport source storage container for transporting (or temporarily storing) radioactive therapy sources and a working source storage container for afterloading equipment.
3.4 Applicator A special container that is pre-placed in the human cavity, duct or tissue for the radioactive source to reside or move and implement treatment, also known as an applicator. For example, a needle, tube or applicator with other special shapes. 4 Protection requirements for afterloading radiotherapy equipment
4.1 Radioactive source
4.1.1 Radioactive sources for afterloading radiotherapy must comply with the provisions of GB4076. 4.1.2 The radioactive source must have an instruction manual and inspection certificate provided by the manufacturer. The instructions shall state the radioactive source number, nuclide name, chemical symbol, equivalent activity, surface contamination and leakage detection, detection period and name of the production unit, etc. 4.1.3 Before using the radioactive source, there must be a reference point air kerma rate approved by the legal metrology agency, and its total uncertainty shall not exceed ±5%. 4.1.4 The replacement of radioactive sources must be carried out by qualified professional technicians under the supervision of radiation protection personnel. 4.1.5 The transportation of radioactive sources must comply with the provisions of GB11806. 4.1.6 Decommissioned radioactive sources must be promptly returned to the original manufacturer or sent to a designated radioactive waste repository for unified treatment or proper storage. 4.2 Source
Approved by the State Administration of Technical Supervision on May 23, 1996 158bzxz.net
Implemented on December 1, 1996
GB16364-1996
4.2.1 The surface of the radioactive source storage container must be marked with the name of the radioactive nuclide, the maximum allowable loading activity and a firm and eye-catching ionizing radiation warning sign (see GB2894).
4.2.2 When the maximum allowable activity is loaded in the source (or working storage source) during transportation, the air kerma rate of the leaked radiation at any position 5 cm away from the surface of the storage container shall not be greater than 100μGy·h; the air kerma rate of the leaked radiation at any point on the spherical surface 100 cm away from the source surface shall not be greater than 10uGy·hl. 4.2.3 The transport storage container (or working storage container) loaded with radioactive sources for afterloading therapy must be stored in a radiotherapy room or a special storage warehouse where general personnel are restricted from entering, except for transportation. 4.3 Applicator
The shape, structural design and material selection of the applicator should be adapted to the anatomical characteristics of the target area to ensure that the radioactive source can normally reside or move therein, and form various predetermined dose distributions in accordance with dosimetric principles to maximize the protection of adjacent normal tissues and organs. 4.4 Radioactive Source Control and Transmission
4.4.1 The control system of afterloading radiotherapy equipment must be able to accurately control the irradiation conditions, and should have a display of the source position of the starting, transmission, residence and return of the radioactive source to the working storage container, as well as a display of the treatment date, channel, total irradiation time and countdown time. 4.4.2 The control system of afterloading radiotherapy equipment should have multiple protection and interlocking devices such as safety locks. It must be possible to prevent the patient from being accidentally irradiated due to electrical or mechanical failures or misoperation such as failure of timer control, radiation source transmission system, source channel or control program errors, and radiation source connection detachment. It is strictly forbidden to operate under the condition of removing the protection and interlocking control device. 4.4.3 During radiotherapy, when power outage, source jam or accidental interruption of irradiation occurs, the radiation source must be able to automatically return to the working source storage device. The irradiation time and dose must be displayed and recorded at the same time until the next irradiation begins, and an audible and visual alarm signal should be issued. When the automatic source return device fails, there must be manual source return measures for emergency treatment. 4.4.4 On the console, it must be possible to display the status of the radiation source output from the working source storage device and returning to the storage position through radiation monitoring. 4.4.5 The timing error of controlling the irradiation time must be less than 1%. 4.4.6 The radiation source transmission pipeline connecting each channel of the source storage device and the source applicator and the source applicator should be as smooth as possible, with the minimum allowable curvature radius to ensure unimpeded transmission of the radiation source. 4.4.7 When connecting the applicator to the radiation source transmission pipeline, the joints must be tightly connected and firm to prevent the radiation source from rushing out or falling off. 4.4.8 The deviation of the radiation source from the source applicator to the stationary position must not be greater than ±1mm. 4.4.9 The maximum number of safe transmissions of the radiation source given by the manufacturer must be within the maximum number of transmissions without radiation source falling off, jamming, or other faults. 4.4.10 The maximum transmission time of the radiation source from the source reservoir to the applicator must be given in the random documents of the radiotherapy machine. 5 Protection requirements for after-loading radiotherapy rooms
5.1 The radiation therapy room must be designed by professionals, and the treatment room must be separated from the preparation room and the control room. The usable area of the treatment room should not be less than 20m.
5.2 The entrance to the treatment room must adopt a maze design, with door interlocks and sound and light alarms on the door of the treatment room. An emergency switch and a radiation source monitor that can quickly return the radiation source to the source reservoir should be installed in the treatment room. 5.3 The shielding thickness of the walls and protective doors of the treatment room should comply with the principle of optimal protection to ensure that the radiation dose of the staff and the public meets the requirements of GB4792.
5.4 An observation window (or monitor) and an intercom should be installed between the control room and the treatment room. 6 Protection requirements for afterloading radiotherapy
6.1 A quality assurance plan must be formulated and implemented to ensure accurate doses. It can not only ensure that the treatment area obtains a reasonable dose and its distribution, but also minimize the radiation dose and range of normal tissues. 6.2 During treatment, the technician must pay close attention to the various displays of the control system and the patient's condition in order to promptly detect and eliminate abnormal conditions. 6.3 When implementing radiotherapy, the treatment date, treatment method, treatment source type, activity, number, channel, irradiation time, single irradiation dose address and total dose base, and the residence position and irradiation length of the radiation source in the source applicator must be recorded in detail, and a schematic diagram must be drawn for archiving. 159
GB16364—1996
6.4 During radiotherapy, no one except the patient shall stay in the treatment room. 7 Inspection of after-installed radiotherapy equipment
7.1 Acceptance inspection Before the newly installed or overhauled radiotherapy equipment is officially put into use, professional and technical personnel must be organized to conduct acceptance inspection. The inspection items are as follows:
a. Measurement of the leakage radiation air kerma rate at any position 5 cm away from the surface of the reservoir and at any point 100 cm away from the surface of the reservoir;
Note: 1) When measuring at 5 cm away from the surface of the reservoir, the average value of the leakage radiation air kerma rate should be taken within a range of no more than 10 cm2; 2) When measuring at 100 cm away from the surface of the reservoir, the average value of the leakage radiation air kerma rate should be taken within a range of no more than 100 cm2. The inspection of the source position indication, sound and light alarm, dose monitoring, monitor, intercom and timer operation functions of the radiotherapy machine console; b.
Measurement of the air kerma rate of the reference point of the radiotherapy source; c.
The movement state of the radiotherapy source in the transmission system and the source applicator (staying, stepping and oscillation) and the function of returning to the source storage device; d.
Determination of the transmission time of the radiotherapy source from the source storage device to the predetermined position in the source applicator; Error inspection of the radiotherapy machine control timer; Note: Select 5 preset irradiation times (not less than 1% of the maximum preset value), respectively measure and calculate the average percentage error of the actual duration of each preset time, and then calculate the average value of the average percentage error of the 5 preset irradiation times. Calibration of radiation dose monitoring instruments;
Surface contamination and leakage of the radiotherapy source, surface contamination detection of the source applicator, treatment bed and other equipment, h.
i. Deviation inspection of the resident position of the radiotherapy source in the source applicator; Measurement of radiation levels in the radiotherapy room and its surrounding environment. j
7.2 Regular inspection Radiotherapy equipment in use must be inspected regularly. The inspection items and cycles are as follows: Items a, c, f, g, and h in 7.1 once a year; Items e, f, and i in 7.1 once a month; Items b and d in 7.1 once a day. When any of them is suspected of being damaged or having problems or other problems, inspection should be carried out at any time. 7.3 Source replacement inspection After each replacement of the radioactive source of the radiotherapy machine, ac, h, i, and j in 7.1 shall be inspected once respectively. 7.4 Decay correction Effective activity of the radioactive source and reference point air kerma rate, 192Ir once before each irradiation, °Co once a month, 137Cs once every six months.
Additional remarks:
This standard was proposed by the Ministry of Health of the People's Republic of China. This standard was drafted by the Institute of Radiation Medicine of Shandong Academy of Medical Sciences. The main drafters of this standard are Zong Xiyuan, Deng Daping, Sun Zuozhong, and Yang Yingxiao. This standard is interpreted by the Ministry of Health's Industrial Hygiene Laboratory, the technical unit entrusted by the Ministry of Health. 160
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