|MEDICAL EDUCATION TEACHING NOTE
|Year : 2019 | Volume
| Issue : 2 | Page : 90-93
Radiological protection and safety: Putting patients first
Department of Radiology, Holy Family Hospital, Thodupuzha, Kerala, India
|Date of Submission||21-Jun-2019|
|Date of Decision||30-Sep-2019|
|Date of Acceptance||22-Oct-2019|
|Date of Web Publication||09-Jan-2020|
Dr. Reddy Ravikanth
Department of Radiology, Holy Family Hospital, Thodupuzha - 685 605, Kerala
Source of Support: None, Conflict of Interest: None
The concept of radiation safety has always been a hot topic, especially with the late reports pointing to increased hazards with chronic radiation exposure for patients and medical personnel alike. Appropriate use of equipment include collimation, optimizing beam-on time, minimizing distances between image intensifier and patient, ensuring sufficient distance between patient and x-ray tube, and optimizing exposure rates for image quality and dose. Present day diagnostic radiology relies on three radiation protection principles - Justification of practice safety, optimization of radiation exposure ALARA, and dose limitation. General practitioners need a working knowledge of radiation safety as to adequately inform their patients of the risks-benefit ratio of diagnostic imaging procedures
Keywords: Radiation Protection, Radiation safety, Justification, Optimization, ALARA
|How to cite this article:|
Ravikanth R. Radiological protection and safety: Putting patients first. BLDE Univ J Health Sci 2019;4:90-3
Radiation exposures to patients and staffs are a major source of artificial radiation. The utilization of radiation exposures in modern medicine has enabled progress across all facets of medicine. In recent times, diagnostic radiology, radiotherapy, and nuclear medicine have evolved with advanced techniques for better diagnosis of clinical conditions known to be humanity since the beginning of time. Technetium-99m, fluorine-18, and iodine-131 are essential radioactive isotopes used in majority of nuclear medicine procedures. The National Commission on Radiological Protection (NCRP) recommended optimized radiation exposure protocols which are the mainstay for as low as reasonably achievable (ALARA) principle. Justification of practice safety, optimization of radiation exposure - ALARA, and dose limitation are the three radiation protection principles, on which the present-day diagnostic radiology relies on.
Personnel training in radiation safety that is approved by the competent authority should be made mandatory in institutes practicing nuclear medicine which are in possession of gamma and neutron sources. Efforts should be made to create awareness and to educate the general public about radiological safety through safety posters and advertisements. Information about their role, functions, safety requirements, and regulatory processes should be disseminated by the Atomic Energy Regulatory Board (AERB) of respective countries to ensure that sources of ionizing radiations are safely transported, used, and handled without causing harm to general public and environment.
Utmost care is to be taken to achieve adequate dose reduction by minimizing the radiation beam to only the area of interest in adults and children. Dose reduction in children can be achieved by not using routine adult factors and instead of using specific technical factors suitable for children. In nuclear medicine, acceptable image quality can still be achieved by administering radiopharmaceuticals with activity lower than adults in children because of the relatively small body surface area. High-dose procedures such as barium enema and pelvic computed tomography should be used with caution during the pregnancy. Factors such as whether a patient is pregnant and whether the fetus is in the primary radiation area should be determined prior to the diagnostic procedure. In nuclear medicine, radioactivity cannot be changed in the course of decay of the radiopharmaceutical and depends on the magnitude of dose administered. During pregnancy, diagnostic studies such as ventilation/perfusion lung scans, extremity, and chest radiographs can be safely carried out as the location is away from the fetus. Moreover, sometimes, the risk of radiation is far lesser than the risk of not making timely and accurate diagnosis. However, proceeding with the radiological investigation for arriving at the correct diagnosis should be carried out with utmost care, and adequate steps should be taken to prevent excess radiation to the fetus. Tailoring the examination until achieving the necessary diagnosis with abrupt termination of the radiological procedure is a dose reduction strategy, when the area of interest is close to the fetus, or when the radiological procedure has dosage that is close to the high diagnostic dose range. Frequent voiding of bladder with adequate water intake is a dose reduction strategy in nuclear medicine and works by reducing the residing time of the radiopharmaceutical in the urinary bladder, and thus, achieving overall dose reduction to the fetus and to the pelvic organs.
The optimization of radiological protection alongside following standard protocols for radiological procedures is to minimize the risk of the patient and personnel. Benefit: risk ratio is improved for patients when radiological examinations are justified, and when principles of quality control and strict adherence to quality assurance are incorporated. It is the responsibility of nuclear medicine physicist and the radiologist to maintain an inventory of radioactive sources available in the hospital as well as to update it from time to time. Radiation hazard or nuclear radiation warning signs should be displayed wherever radioactive isotopes are stored or manipulated, or radiological procedures are being performed. Increasing source to patient distance, minimizing exposure times, and appropriate radiation shielding are protection measures for external radiation exposure hazards.
Radiation safety program which comprises implementing new procedures and proposed changes to equipment and facilities has to be overseen by the Radiation Safety Committee (RSC) from time to time. Radiation safety pyramid provided by RSC that illustrates the workflow of responsibility should be displayed in the radiology department of the hospital. RSC approves the radiation safety program implemented by radiation safety officers and staffs. Initiatives must be taken for regulatory compliance and safety management of radioactive equipment as well as sealed and unsealed radioactive materials. In the chain of radiation safety responsibility, radiation workers handling radioactive materials and sources at the bottom of the safety pyramid form the most important link. The maintenance of occupational radiation exposure records and quarterly reviews of all personnel should be undertaken by the RSC, giving priority to individuals whose occupational exposure appears excessive. RSC formulates regulatory policies for quality control testing, calibration of radiation-generating devices, nuclear medicine equipment, radiation protection apparel, radioisotope waste, and shipment summary.
The Food and drug administration's center for devices and radiological health, which organizes radiation safety programs from time to time regarding the usage of radiation-emitting products should also enforce mandatory requirements for radiation safety by organizing voluntary programs and by promoting public–private partnerships for their safe utility by medical personnel. Public and professionals alike are trained in these programs for ensuring their safety. Adequate education should be provided regarding radiation-emitting sources, beneficial uses of radiation, and the risks posed by a wide range of radiation emissions. These programs also ensure that patients receive the correct radiation dose at the appropriate time using the appropriate imaging modality. Radiation safety programs should be designed to protect patients, medical personnel, general public, and environment by ensuring safe handling and storage of radioactive materials. Annual review of the entire radiation safety program should be undertaken to determine compliance with the regulatory requirements. Remedial action is recommended to foresee deficits in the radiation safety program.
Appropriate usage of radiation-emitting machines and hardware; manufacturing safe and low-dose equipment; awareness and understanding of radiation safety and protection principles by users; awareness of radiation risks and protection concepts by patients and consumers; protection from hazardous radiation overdoses; and minimizing unnecessary and low-yield radiation exposures form the mainstay strategies of radiation safety and protection. Appropriate radiation regulatory authorities and surveillance committees should be formed, which provide with necessary information, yearly statistics, continuous surveillance, and updated radiation safety protocols from time to time. RSC is also required to take timely action when necessary. Certification and training programs of medical personnel dealing with radiation should be made mandatory for ensuring safe radiation practices. Recognizing the fact that we all have a role in promoting radiation safety should be the aim of radiation safety programs.
Radiation monitoring guidelines are as under
- Who needs a dosimeter – Because of the possible hazards when dealing with radiation, AERB guidelines require all personnel to wear proper radiation monitoring devices at all times while using energized radiographic equipment or near radioactive sources
- Proper use of dosimeter – Monitors are issued and must be worn to measure occupational exposures
- Where to wear the dosimeter – Badges should be clipped to an article of clothing at the collar level; however, when working in fluoroscopy or on portable procedures, the badge is to be worn outside the lead apron, clipped to the uniform collar, and never on the lead apron
- Misuse of the dosimeter – A badge that has been assigned to an individual may not be used by any other person. The participants' number is a lifetime assignment and is not transferable to another person. Badges must not be tampered with in any manner. Keep your badge away from radiation sources when not in use
- Exposure data – Exposure results are received at quarterly intervals from the Bhabha Atomic Research Centre. This report will be posted in a designated area so that each individual is aware of his/her exposure each quarter. This report must be reviewed and initialed by each badge wearer to verify that the individual has seen their report, in compliance with the AERB guidelines
- Replacement of badge – Every 3 months, the badge must be returned and replaced with a new one. Late changes will make accurate dose determination impossible.
Radiation protection guidelines for the patient are as under
- The possibility of pregnancy always enquires about the chance of pregnancy before any X-ray exposures are taken. Follow appropriate hospital procedures and guidelines on patient pregnancy
- Collimation – Collimating devices capable of restricting the useful beam to the area of clinical interest should be used
- Radiographic filtration – The aluminum equivalent of the total filtration in the useful beam should not be <0.5 mm when operating below 50 kVp, 1.5 mm between 50–70 kVp, and 2.5 mm above 70 kVp. Minimum filtration equals inherent plus added
- Gonadal shielding – Gonadal shielding of not <0.5 mm lead equivalent should be used for patients who have not passed the reproductive age during radiographic procedures, in which the gonads are in the useful beam, except for cases, in which this would interfere with the diagnostic procedure
- Entrance skin exposure (ESE) measurements – It is essential that ESE measurements be available for common X-ray examinations preformed with each X-ray unit.
Radiation protection guidelines for personnel are as under
- Holding patient restrictions: No person shall be regularly employed to hold patients or image plates during exposures. When it is necessary to restrain the patient, mechanical supporting or restraining devices should be used. If the patient or image plates must be held by an individual that should be protected with appropriate shielding devices such as protective gloves and a protective apron of at least 0.25-mm lead equivalent. No part of the attendant's body should be in the useful beam
- Mechanical devices (instead of persons) must be used whenever possible to restrain patients. Examples include adjustable restraints, sponges, sheets, tape, chest unit, and velcro straps
- Always close doors, stay behind lead barriers and use interlocked doors
- Protective tube housing protects both radiographer and patient from off-focus radiation X-rays emitted through the X-ray tube window and leakage through sides of the collimator
- Shielding lead wrap-around apron no <0.25 mm lead in thickness (0.5 mm is commonly used). NCRP recommends a lead apron of number <0.5 mm equivalent for fluoroscopic examinations. Lead protective gloves number <0.25 mm lead in thickness
- Never leave personal protective barrier while making X-ray exposures.
Reliable sources of radiation safety information are available at
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
The 2007 recommendations of the international commission on radiological protection. ICRP publication 103. Ann ICRP 2007;37:1-332.
ICRP publication 105. Radiation protection in medicine. Ann ICRP 2007;37:1-63.
National Council on Radiation Protection and Measurements. Ionizing Radiation Exposure of the Population of the United States: NCRP Report No. 160. Bethesda MD: National Council on Radiation Protection and Measurements; 2009.