TOPIC: RADIATION PROTECTION
🌟 IMPORTANT POINTS TO REMEMBER
🔹Natural radiation: It yields an average annual dose of about 0.79 mSv. It has three components: cosmic radiation, terrestrial radiation and internal sources.
🔹Cosmic radiation: It includes both energetic subatomic particles and photons of extraterrestrial origin that reach the earth.
🔹Terrestrial radiation: The dose equivalent rate varies with the type of soils and their content of naturally occurring radionucleotides such as radium, uranium and thorium with their decay products and potassium-40.
🔹Internal sources: The sources of internal radiation are radionuclides that are taken up from the external environment by inhalation.
🔹Artificial (or man-made) radiation: It includes radiation from healing art and consumer and industrial products and sources.
🔹MPD is defined as the maximum dose that a person or a specific part of the body should be allowed to receive in a given period. It is the dose of radiation that the body can render with little or no injury.
🔹MAD: It is the dose which is measured by the measurement of the entire radiation dose received by the personnel in their life.
🔹ALARA concept: All exposure radiation must be kept ‘as low as reasonably achievable’.
🔹Patient selection: Increased source-to-patient distance reduces the amount of radiation to patient.
🔹Collimation: The tissue area exposed to primary X-ray beam should not exceed the minimum coverage consistent with meeting diagnostic requirements and clinical feasibility.
🔹Filtration: Purpose of conventional filtration is to selectively remove low-energy X-ray photons from the X-ray beam which will result in decreased patient exposure with no loss of radiographic information.
🔹PID: Long PID is preferred because of less divergence of the X-ray beam.
🔹Head leakage: Dental X-ray machine must be monitored for leakage radiation.
🔹Tube head drift: The tube head of dental X-ray machine should not move or drift in any direction after the positioning of the patient.
🔹Kilovoltage: Patient skin exposure is decreased as the kVp increases.
🔹Milliampere seconds: Usually exposure time should be less by increasing the milliamperage of the machine.
🔹Film selection: Film E is twice faster than D film and exposure is 0.2500. RVG should be used if possible.
🔹Lead apron: Lead apron should be used to minimise unnecessary radiation.
🔹Thyroid collar: Thyroid collars are used when the thyroid gland is in the primary beam.
🔹Lead glass goggles: The use of lead glass goggles has been recommended for the protection of eyes.
🔹Intraoral technique: Radiograph may be taken only by operators who are adequately trained and competent.
🔹Timing device: The use of more sensitive X-ray films with extremely short exposure time should be made mandatory.
🔹Precautions taken for pregnant women and children: Procedures involving exposure to the fetus area should be avoided.
🔹Film processing: From the beginning of exposure of film till its processing, careful handling of the film should be done.
🔹Viewing: To obtain maximum detail radiograph should be viewed in a dimly lighted room with a properly functioning illuminator.
🔹Departmental protection: The Department should lay down requirements of radiation protection to walls, floor, ceiling and doors to shield persons in adjacent rooms.
🔹Time: The total dose received by the workers is directly proportional to the total time spent in handling the source.
🔹Distance: Reduction of exposure due to an increase in distance is governed by the inverse square law.
🔹Avoiding primary beam: The operator should not be in line with the primary beam.
🔹Shielding: A protective barrier that absorbs the primary beam can be incorporated into the office design.
🔹Equipment: All safety procedures recommended for reducing the dose to the patients are applied for operator protection also.
🔹Radiographic technique: Radiographs should be taken by trained staff only.
🔹Personal monitoring: Monitoring is recommended for the period of 3–6 months after new radiographic equipment is installed to ensure that dose limits are not being exceeded.
🔹Radiation precaution after nuclear medicine examination: Direct contact with patient blood, faeces, urine, vomitus or other body fluid must be avoided. Rubber gloves must be used.
🔹Regulation of ionising radiation: During the exposure a designated controlled area must exist around the X-ray set, and only the patient is allowed in this area.
🔹Teletherapy: The patient must be positioned with great care for given SSD and field size.
🔹Wedge filter: The door must be properly closed before the machine is switched on.
🔹Brachytherapy: The source must never be touched with the hands.
🔹Swipe test: Periodic leak testing of brachytherapy sources should be carried out.
🔹Nuclear medicine: It should be stored in a container when not in use.