DEPARTMENT OF HEALTH, EDUCATION AND WELFARE
Public Health Service
Health Services Administration
Indian Health Service
INDIAN HEALTH CIRCULAR NO. 75-02
Effective Date: January 21, 1975
- Technical Consultant on Radiation Protection
- Reducing Dose to Occupationally Exposed Personnel
- Reducing Dose to Patient
- Shielding and Equipment
- Maintenance of X-ray Equipment
To establish responsibilities and procedures for radiation protection at Indian Health Service facilities using medical and dental X-ray units.
- Reduction of radiation dose to patients to the minimum consistent with clinical requirements. This includes both the elimination of unnecessary exams as well as unnecessary radiation dose to patients during an examination.
- Reduction of radiation exposure to medical, dental and ancillary personnel to the minimum consistent with duties, or to a level which in no case exceeds the limits set by the National Council on Radiation Protection.
- The Service Unit Director responsible for the operation of an Indian Health Service facility utilizing X-ray equipment shall be responsible for the safe working conditions prescribed by this circular and for complying with recommendations of the National Council on Radiation Protection. (Report No.33, 34, 35, and 39.)
He shall insure that:
- A radiation protection supervisor is designated for every installation utilizing x-ray equipment.
- The radiation protection supervisor reviews operating procedures for adherence to recommendations contained in NCRP current reports.
- All personnel utilizing x-ray equipment are instructed in the proper radiation protection practices and that all recommended safety devices are utilized.
- That biennial radiation surveys (and source leak tests where indicated) are conducted and that records of such surveys are on file.
- That corrective measures recommended as a result of surveys and investigations be instituted.
- That personnel monitoring devices are issued and used and that records are maintained of the results of such monitoring. (All occupationally exposed personnel shall be monitored.)
- That only trained personnel be permitted to operate x-ray equipment.
- TECHNICAL CONSULTANT ON RADIATION PROTECTION
The Area Chief, Office of Environmental Health, or his designated representative, shall be the technical consultant on radiation protection and shall report directly to the Service Unit Director. He shall:
- Review established operational practices and make recommendations necessary to assure that each worker’s exposure to radiation is kept as far below the maximum permissible exposure as is practicable, and that patient exposure is kept to a minimum.
- Instruct Service Unit Radiation Protection supervisors in the types of injuries that may result from overexposure to radiation, and in the techniques to be used in protecting patients against unnecessary x-ray exposure.
- Arrange for and insure the proper operation of a personnel monitoring system to be used by all personnel within the Area who are occupationally exposed to sources of radiation. (Personnel monitoring service is provided through an Indian Health service Agency-wide contract.)
- Receive from the contracting agent all reports of personnel monitoring devices, review and record results and forward the reports to the Service Unit radiation protection supervisor.
- Conduct biennial radiation surveys at each Indian Health Service facility which uses radiation equipment, and maintain records of such surveys.
- Furnish written reports to headquarters of all biennial radiation surveys.
- Investigate, as appropriate, cases of excessive or abnormal exposure to determine the cause and recommend measures to prevent recurrence. Headquarters shall be informed of all excessive exposure and the recommendations rendered.
- Review all new, remodeling and rearrangement plans for x-ray units and evaluate protection provided.
- Survey x-ray installations after remodeling or rearrangement has been completed.
- Insure that all biennial surveys of equipment shall include an "Organ Dose Index System” evaluation. The ODIS is designed to serve as an adjunct to the biennial equipment survey and shall not replace the required biennial survey of equipment.
- REDUCING DOSE TO OCCUPATIONALLY EXPOSED PERSONNEL
- General x-ray procedures:
- Only persons required for the x-ray procedure shall be permitted in the x-ray room during an exposure. All such persons, except the patient, shall wear protective aprons and gloves. No parts of the bodies of these persons shall be in the useful beam.
- No persons occupationally exposed to radiation shall be permitted to hold patients during exposures, nor shall any person be regularly used for this service.
- Parents and patients shall not be used to hold infants and small children during x-ray procedure, unless in emergency and then such persons shall utilize protective devices.
- Procedures applicable to fluoroscope units:
- Fluoroscopy should be performed only by physicians properly trained in fluoroscopic procedures.
- The fluoroscopist's eyes should be sufficiently dark-adapted for the visual task required before commencing non-image intensified fluoroscopy.
- The hand of the fluoroscopist should not be placed in the useful beam unless the beam is attenuated by the patient and a protective glove of at least one-quarter millimeter lead or equivalent is worn.
- Procedures applicable to radiographic units:
- The operator of mobile x-ray equipment should stand as far as possible from the patient, the tube, and the useful beam. He should wear a protective apron or stand behind a suitable shield.
- Mobile equipment should be used only for examinations where it is impratical to transfer patients to permanent radiographic installations.
- The exposure switch on mobile units shall be so arranged that the operator can stand at least six feet from the patient, the x-ray tube, and the useful beam.
- The Service Unit radiation protection supervisor shall assure himself that operators of mobile equipment understand the proper use and limitations of the equipment so as to avoid needless exposure of the patient, and other persons in the vicinity.
- The exposure switch on fixed radiographic units, except for those used in conjunction with "spot film" devices in fluoroscopy, shall be so arranged that it cannot be conveniently operated outside a shielded area.
- Procedures applicable to dental units:
- In no case shall the film be held by the dentist or his assistant during exposure.
- Unless protective shielding is provided for the operator, the installation should be so arranged that the operator, when making exposures, can stand at least 6 feet from the patient and well away from the useful beam. When protective shielding is provided, the operator shall always be entirely behind the shield during the exposure.
- Neither the tube housing nor the cone shall be hand held during the exposure.
- REDUCING DOSE TO THE PATIENT
- The exposure to the patients shall be kept to the practical minimum consistent with clinical objectives.
- Patients shall be x-rayed only when clinically indicated.
- The useful beam should be limited to the smallest area practicable and consistent with the objectives of the radiological examination or treatment. The x-ray operator shall enforce proper collimation through use of, either an adequate assortment of cones, diaphragms, or an adjustable collimator with beam-defining light.
- Appropriate and effective gonadal shielding should be utilized on patients during selected medical x-ray examinations. At present only male gonaldal shielding is achievable on a practical level.
It is emphasized that the indications for particular examinations where gonadal shielding is appropriate is flexible. Physicians should determine the procedures where shielding is appropriate using the criteria below:
- The gonads will be within the primary x-ray beam area, or within close proximity (i.e., 5 cm.) to the beam edge of an adjacent primary beam exposure area, despite proper beam limitation.
- The clinical objectives of the examination will not be compromised.
- The patient has at least a reasonable reproductive potential.
- Only screens and films appropriate to the examination should be used.
- Outdated film or film that has been exposed to heat and x-rays may be faulty and should not be used for x-ray exposures.
- Planning and preparation of the patient is of considerable importance in obtaining high quality radiographs and avoiding the unnecessary exposure of retakes. Patients should be instructed in the proper methods of breathing for chest films and other exposures to avoid motion during radiographic procedures.
- In order to avoid repeating the exposure, the technologist should keep in mind the following points:
- Keep film loading bench clear and free of dust and moisture.
- Clean cassette screen frequently.
- Screen and cassettes as a component should have an identification number. This will provide a means of identifying cassettes responsible for unsatisfactory radiographs.
- Check screens for reflective power and for sharpness using the wire mesh screen method.
- Keep developing and fixing solutions fresh and clean, and stir well before using. The manufacturers recommendations should be followed with regard to film development.
- SHIELDING AND EQUIPMENT
- Before rearranging existing x-ray equipment, installing new x-ray equipment, or constructing new facilities to house x-ray equipment at any installation, the proposed changes shall be reviewed by the Area Chief, Office of Environmental Health, or his designated representative and the Area Construction and Maintenance Officer. The Area Chief of OEH shall prepare a written report of his findings and furnish Headquarters Chief of OEH with a copy. Construction of new facilities or alterations to house x-ray equipment must receive prior approval by Headquarters as required by Real Property Management Manual Circular No. IH-17.
- All new x-ray systems and major components manufactured and installed after August 1, 1974 must comply with the Federal diagnostic x-ray equipment standard.
- All x-ray facilities shall have shielding which conforms to the recommendations of NCRP Report No. 34.
- Aluminum filtration shall be installed permanently in the useful beam of all x-ray units, with the exception of multi-purpose machines such as those used for mammography. All filtration shall be in accordance with NCRP Reports No. 33, 34, and 35.
- Doors to each x-ray room should be provided with a sign warning "X-Ray Room - - Knock Before Entering."
- Mobile x-ray equipment used routinely in one location, i.e., the unit is located and operated in the same room, shall be considered a fixed installation and as such shall comply with all shielding and other requirements of fixed installations as indicated in NCRP Reports No. 33, 34 and 35.
- MAINTENANCE OF X-RAY EQUIPMENT
- X-ray equipment at each installation shall be inspected at least every two years to reduce the possibility of overexposure due to faulty equipment. Inspection should be performed only by qualified personnel. Records shall be maintained which indicate date of inspection, name of inspector. Defective equipment should be promptly repaired, replaced, or removed from service.
This circular supersedes Indian Health Service Circular No. 62-11 of July 11, 1962, and Circular No. 70-02 of July 31, 1970.
/Emery A. Johnson, M.D./
Emery A. Johnson, M.D.
Assistant Surgeon General
Director, Indian Health Service
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