Alara: Principles Of Radiation Protection

ALARA: Principles Of Radiation Protection

What is ALARA principle. discuss the radiation protection for dental patient.
Answer. ALARA means “as low as reasonably achievable” ALARAprinciple recognizes the possibility that no matter how small the dosage is some stochastic effect may occur.

ALARA Principle is as Follows:

• In radiation workers:
  • Occupationally exposed person—50 mSv or 5 rem in any one year.
  • Women of reproductive age and pregnancy should not exceed 10 mSv or 1 rem.
• Members of the public:
  • Annual effective dose for public should not exceed 1 mSv or 0.1 rem.
  • In any one year members of public should not receive an effective dose equivalent in cases of 5 mSv or 0.5 rem.

“Understanding the principles of ALARA in medical imaging: Q&A explained”

Radiation hazards

Radiation Protection of dental Patient

• X-ray machine: Good machines of reputed companies should be used.
• Selection of film: F- and E-speed films are used as they are of good quality and are highly sensitive. E speed films or Ekta speed films reduce exposure to 40%.
• Focal spot film distance: Longer is the focal spot film distance decrease is in the exposed tissue volume.
• Source skin distance: Increase in the source skin distance reduces the size of beam and reduces the volume of tissue irradiation which decreases the patient dose.

Radiation risk in diagnostic imaging

“Importance of studying ALARA for better radiation safety: Questions explained”

• Filtration: Low energy X-ray beam is removed by the filtration. As these X-rays do not contribute to the image formation they should be removed before they reach to the patient as they lead to the radiation exposure.
• X-ray collimation: It prevent the scattering. Beam should be collimated so that it is not more than 7 cm in diameter at the face of patient. Rectangular collimators should be preferred as they reduce the amount of tissue radiation.
• Intensifying screen: Use of rare earth screen decreases dosage for extraoral films.
• Grid: Grid decreases the fogginess of film due to the secondary radiation, this reduces the need for repeating the film.
• Kilovoltage: Operation of X-ray unit should be done at 60 to 90 kVp. X-ray beam of low kilovoltage leads to the higher patient doses, mainly to skin.

Radiotherapy side effects

“Common challenges in applying ALARA principles effectively: FAQs provided”

• Position-indicating devices: A 12 to 16 inches long position indicating device reduces exposure to patient as compared to short position indicating device. Open ended, circular or rectangular lead-lined cylinders are preferred to direct the X-ray beam.
• Lead aprons should be used who have lead content equivalent to 0.25 mm aluminum which is to be worn by patient during taking the radiograph.
• Thyroid collars should be weared to protect thyroid gland from radiation.
• Film-holding devices: They stabilize the X-ray film in mouth and so the hands of patient are not exposed to radiation.
• RVG: It decreases the dose of radiation required in IOPA.