Radiation

Radiation Safety Officer

The chairperson of the Department of Diagnostic Sciences and Patient Services is appointed as the radiation safety officer for all diagnostic radiation sources at the clinics under BUSDM's jurisdiction, including those in the main facility and at the 930 Commonwealth Avenue practice.

The responsibilities of the radiation safety officer include

• establishing, implementing, and monitoring guidelines and policies on radiographic practices.
• approving any purchases and remodeling of radiographic facilities.
• monitoring performance levels of X-ray units.
• monitoring radiation safety procedures.
• investigating reported or suspected incidents of misuse or hazards of radiation equipment.
• implementing quality assurance programs.
• maintaining records for each X-ray unit inspection.
• educating all new staff to the radiation policies including technique, safety practices, prescribing procedures, and state and federal radiation rules and regulations.
• providing periodic continuing education programs for all staff operating X-ray generating and processing equipment.
• working in association with the radiation safety committee at Boston University Medical Center.

Clinicians

Only dentists, dental hygienists, certified dental assistants, other personnel who are certified, and students who have completed sufficient training on manikins are permitted to make patient exposures.

• Dentists employed by BUSDM as faculty, clinicians, or in the postdoctoral programs are authorized to operate X-ray equipment.
• Registered dental hygienists employed in the various clinics are authorized to operate X-ray equipment.
• Dental assistants must be certified to operate the radiographic equipment.
• Surgical assistants are required to be certified to operate X-ray equipment.
• Any other staff must also complete a radiology certification program to operate any X-ray equipment. didactic course which includes radiation safety and
• Dental students must complete the Radiology Preclinical Laboratory training to a satisfactory level before being allowed to make X-ray exposures on patients. Faculty supervision is required.

Courses that use X-ray equipment by students lacking certification must be supervised by a member of BUSDM faculty.


Pregnancy

Any X-ray operator who is pregnant may voluntarily declare her pregnancy and the estimated date of conception in writing to the Radiation Safety Officer. Thereafter, her occupational radiation exposure shall be limited to .5 msv per month as required by the NRC (National Regulatory Commission.)

It is the responsibility of the operator to decide whether the risks to her or to a known or potential unborn child are acceptable.


Staff and Faculty Training

• Periodic training sessions are provided for all personnel using X-ray equipment.
• Radiation safety sessions are required of all new personnel and postdoctoral residents who may be using X-ray equipment.
• Auxiliary staffs are also required to meet the requirements of DANB or other professional organizations as they may apply.

Exposure Criteria

• All radiographs are prescribed in writing by a BUSDM faculty member who is a dentist or by a postdoctoral resident.
• All prescriptions are made after determining the patient’s need by reviewing the medical and dental history and by performing a clinical exam. The selection criteria follows those recommended in the enclosed chart developed by representatives of various dental and federal agencies.
• Selection Criteria
• If prior radiographs are available, they are obtained and evaluated prior to taking new radiographs.
• Retakes are taken after evaluating the initial film, which does not meet diagnostic criteria, and after determining the technical error. Supervision of faculty to aid in the correction of the error is required. A full mouth series is acceptable if the radiographs are of diagnostic quality and exhibit the following features:
  • Apex of each tooth will be visible at least once with 1 to 2 mm of bone surrounding it.
  • The interproximal region of each tooth will be open in at least one radiograph.
  • A panoramic film will be taken to visualize unerupted/ partially erupted third molars if these teeth are not visualized on the molar periapical films.
• Radiographs are made only on patients who are capable of complying with the procedure.
• No radiographs are taken on a routine basis.
• Radiographs may be taken for research purposes with institutional review board approval.
• Radiographs solely for teaching, training, insurance, or other administrative purposes are not permitted.
• Radiographs are not taken solely for dental board examination purposes.
• Students must become proficient in intra-oral techniques on mannequins prior to exposing patients.
• Retakes are taken after evaluating the initial film, which does not meet diagnostic criteria, and after determining the technical error. Supervision of faculty to aid in the correction of the error is required.
• All radiographic interpretations are noted in the patient’s chart.

Safety Procedures

• All patients are draped with lead aprons and, where the technique allows, thyroid collars.
• E-speed intra-oral film is used except in the Endodontic Department where D-speed film is used.
• No person other than the patient is allowed to be in the X-ray operatory during the exposure. If assistance is required, non-occupationally exposed persons (preferably a member of the patient’s family) will be asked to assist and will be draped with a separate apron.
• Extra-oral exposures employ screen-film combinations of the highest speed consistent with their diagnostic purpose. As a rule, this implies use of rare earth screens and T-grain film.
• The operator stands behind adequate barriers when exposing a film. The door to the operatory must be closed.
• When a mobile X-ray unit is used or when no barriers are present, the operator is required to stand 6 feet and 90 to 135 degrees from the patient.
• Film holding devices, particularly the Rinn equipment, are used to avoid the patient holding it with a finger.

Operator Safety

• Maximum Permissible Dose: 2rem/year
• Do Not Hold the Film in the Patient’s Mouth
• Achieve Certification and Continuing Education
• Wear Radiation Badges
• Install Adequate Barriers: Lead Lined Walls, Leaded Windows, Adequately Thick Cement or Brick Walls Movable Lead Barriers
• Obey the Position and Distance Rule: 6 Feet from the Patient 90º - 135º to the Central Beam

Patient Safety

• ALARA: As Low As Reasonably Achievable
• Take Films by Prescription: Only When Necessary
• Use Fast-Speed Film
• Use Proper Processing Procedures and Adhere to Quality Assurance Measures
• Place Lead Apron and Thyroid Collar on Every Patient
• Have Adequate Filtration
• Use Collimation

Radiation Monitoring

• Monitoring of all personnel who are involved in radiographic procedures is available. Badges are to be worn during working hours. Those who do not wish to have a badge are to sign a waiver form.
• Badges are to be worn during working hours on your body between the collar and the waist while exposure is expected to be at its highest. Do not take badges home.
• Dosimetry reports are gathered monthly and filed in the radiology department and are open for inspection.
• Maximum radiation doses allowed are not to exceed those recommended by the NCRP, and preferably much lower.

Patient Records

Radiographic Permission (blue form)

• All radiographic examinations are authorized by Boston University faculty who are dentists. These prescriptions are dated and made after a complete review of the medical and dental history and a clinical exam.
• The amount of radiation to which the patient is exposed is recorded. This includes the type of film, the PID (round or rectangular), the number of films, the exposure time, the kVp, and the mA.
• An initial interpretation of the radiographs is noted.

Treatment Record

• The clinician records the date of exposure, the type and number of films taken, any retakes which are exposed and the reason, and any difficulties which occurred during this procedure.
• Signatures by both the student and the faculty are documented.

Oral Diagnosis/Oral Medicine/and Radiology Screening Form

A more complete interpretation of the radiographic exam is documented.

Radiographs

• All radiographs are mounted and labeled with the patient’s name and date.
• The right and left side is noted on panoramic, other extra-oral films, and on duplicates.
• The films are stored in the chart in the pocket marked “radiographs.”
• Patients who request their films are provided with a duplicate. Original radiographs remain with the patient’s chart.

Physical Facilities and Equipment

• Boston University School of Dental Medicine is in full compliance with state and federal laws pertaining to radiation safety including NCRP.
• All operatories with X-ray equipment have adequate barriers for the operator. This includes either lead lining of the walls and doors or a portable lead barrier in areas where the doors do not close or are not present. All have a transparent leaded panel to permit a safe view of the patient during exposure.
• When circular collimators are used for intra-oral films, the beam diameter at the patient’s face is restricted to 2.75 inches. Rectangular collimators limit the beam to 2.0 inches at the face on the long side. Only open-ended, shielded position-indicating devices are used.
• The target-to-skin distance for intra-oral radiography is not less than 8 inches. When practical, a long position-indicating device of 14 inches or over is used.
• Total filtration is not less than 1.5 mm aluminum equivalent at 70 kVp; 2.5 mm when operating over 90 kVp.
• Exposure control switches are the deadman type and is positioned behind the barrier. All radiation emission terminates after the preset time of exposure. When possible, the X-ray unit has both an audible and a visual indicator to signal exposure termination.
• Radiographic viewing is accomplished with equipment such as dim background lighting where possible, masked viewboxes, opaque mounts, and magnifying glass.
• Information regarding each X-ray unit and processor, its installation date, and all repairs re maintained by the Repair Department. Calibration reports are kept in the Radiology Department.

Lead Aprons

• Lead aprons are hung upon hooks and are discarded after a maximum of five years of use. The date when the apron is first put into circulation is marked on the lower corner
• Lead aprons are hung up between use in each operatory with an X-ray machine. They are not folded.

Quality Assurance

Records are maintained and filed in the Radiology Department with the following information:

• periodic calibrations of X-ray tube output.
• dates and actions to correct any fluctuations of the X-ray equipment output.
• exposure at the end of the PID tests.
• a description of the room housing the X-ray unit.
• results of safety surveys.
• log of the daily step wedge test and weekly solution changes in the radiology clinic.
• Massachusetts Department of Public Health inspection certifications.

Also see Radiation Manual

Infection Control and Safety

• All patients are treated as potentially infectious.
• Proper personal protection equipment is worn including gloves, masks, and lab coats.
• Proper hand washing procedures are adhered to before and after patient contact.
• All equipment is sterilized between patients.
• The operatory is appropriately barriered with headrest covers, tubehead covers, and tape.