907 DEXA

Purpose

To ensure the Principal Investigator (PI) and all research team members assisting with the conduct of clinical research at the Ohio University Heritage College of Osteopathic Medicine’s Clinical and Translational Research Unit (CTRU) are informed about their obligations and responsibilities as they pertain to Good Clinical Practices (GCP), the investigational plan, applicable regulations, and institutional policies.

This Standard Operating Procedure (SOP) ensures correct and safe use of the DEXA unit for data collection conducted under the supervision of the Clinical & Translational Research Unit (CTRU). Attachment templates include:

A: DEXA Scan Information & Waiver Form for Non-Research, B: DEXA Scan Tracking Log

Responsibilities

The CTRU is responsible for developing, implementing, and maintaining SOPs. Creating new or revising an existing SOP is determined by changes to federal regulation, guidelines, institutional policies, or procedures. All applicable documents will be provided to departments and research teams conducting human subject research.

Definitions

Dual-Energy, X-ray Absorptiometry (DEXA): DEXA uses low-dose x-rays of two different energy levels to measure bone density and/or body composition (fat and muscle). There are several types of DEXA units available for different needs and purposes. The DEXA unit in the CTRU is a whole-body scanner, which enables the assessment of body composition and/or bone density of the whole body.

Procedures

1. Operator Training, Examination, and Licensing

• All operators must complete the required radiation safety training mandated by Ohio University’s Risk Management and Safety Department.
• A non-physician operator must hold an active license from the Ohio Department of Health (ODH) to perform bone densitometry.
• After completing these requirements, the CTRU Medical Director or his/her designee must provide oversight and training on the safe use of the DEXA unit. A qualified designee is someone who has obtained the required license(s) defined by the ODH, completed all required training assigned by Ohio University’s Risk Management and Safety Department, has completed human subjects’ research training, and has been performing DEXA scans on a regular basis.
• To become an authorized DEXA operator the trainee must adequately perform 3 DEXA scans under supervision of the CTRU Medical Director or his/her designee. The trainee must demonstrate knowledge of the potential side effects of DEXA scans as well as an understanding of the procedures for monitoring and reporting adverse events. The trainee must be able to answer subjects’ questions about safety issues and the mechanism of action of the DEXA unit. After satisfactory completion of these steps, the trainee can perform DEXA scans as an independent, authorized user.
• Access to the DEXA unit is restricted to individuals who have General X-ray Machine Operator (GXMO) training, RT credentials, or physician licensure in the State of Ohio. Other research staff performing calibration and basic functions not relating to human use may be authorized for usage by the CTRU Medical Director. Any user must undergo the general Radiation Safety Orientation given by the Ohio University Radiation Safety Officer.
• The DEXA unit located in the CTRU has been approved by the ODH as “self-referral screening utilizing radiation generating equipment” for bone density and body composition analysis. Requirements for maintaining a user’s license will be determined by the ODH.

2. Equipment Inspection and Timelines

• The DEXA unit is inspected semi-annually by Ohio University’s Radiation Safety Officer, annually by the Ohio Department of Health (ODH) and a yearly preventive maintenance by the manufacturer as required by ODH.

3. Safety (Radiation Risks)

• The only source of radiation is the DEXA unit in the CTRU. The computer operating the unit displays a notice when radiation is being emitted.
• Exposure to radiation can be controlled or minimized with the use of the collimator, proper processing techniques, immobilization, distance, and time. Lead shielding may be used in certain circumstances, as directed by the University’s Radiation Safety Officer. To monitor cumulative radiation exposure authorized users, trainees, and observers must wear a film badge provided by the University’s Risk Management and Safety Department when the DEXA unit is being operated.
• There are no known risks associated with the amount of radiation a person is exposed to during a DEXA scan. However, although the amount of radiation used during a whole-body DEXA scan is generally very low (0.01 -0.04 mSv), DEXA scans should not be performed on pregnant females.
• Per protocol, all females of childbearing potential (defined as under age 55 or within two years of menopause) who do not have documented sterilization will undergo a urine pregnancy test on the day of the DEXA scan. Pregnancy tests may be performed by CTRU personnel or by external study personnel, provided the test is conducted in a CLIA-waived laboratory using a CLIA-waived urine pregnancy test. Results will be recorded on protocol specific source documentation for research subjects. Prior to performing the DEXA scan, the individual performing the scan must verify documentation of a negative pregnancy test result. For non-research subjects, pregnancy test results will be captured on Attachment A: DEXA Scan Information & Waiver Form for Non-Research.
• Anyone with a positive pregnancy test will be informed of their result, advised to contact their personal physician, and if the woman is a research subject, the PI will be notified. Anyone with a positive pregnancy test will not receive a DEXA scan.

4. DEXA Procedures

• On each day that the DEXA machine is used, the DEXA operator will perform and document daily quality check (QC) prior to the first scan of the day.
• If the scan is for a research project, the operator must verify that the subject has an informed consent on file. If the subject is not being scanned for research purposes, the operator must verify Attachment A: DEXA Scan Information & Waiver Form for Non-Research is completed.
• The operator will explain the procedure to the subject and ask if the subject has any questions prior to proceeding with the scan.
• The operator will obtain the subject’s height and weight. The weight limit for the DEXA table is 450 pounds; the procedure cannot be performed if the subject weighs more than 450 pounds.
• If the subject cannot fit adequately within boundaries of the scanning area the operator can use the partial body scanning method (Appendix C).
• If the subject is a female of childbearing age, the operator will verify that a urine pregnancy test performed on the day of the exam is negative.
• The operator will ask the subject to remove jewelry, body piercings, clothing with zippers or metal buttons, and underwire bra, and to change into scrubs or a gown. Irremovable metal or dense materials such as implants, shrapnel, or surgical hardware are allowed, but need to be recorded and consistent for the duration of the study if the subject is required to have multiple DEXA scans.
• The operator will position the subject on the DEXA table and explain the scan procedure again, instructing the subject to remain still during the entire scan.
• If the subject expresses discomfort, dizziness, signs of nervousness, and/or indicates a desire to withdraw from scanning or stop the procedure, assess the situation and take appropriate steps to ensure subject safety. These may include requesting assistance from CTRU staff, notifying the PI, and/or terminating the procedure.
• Each scan must be recorded on Attachment B: DEXA Scan Tracking Log with the Date, Time, Participant ID or Non-Research Status, Study Name or Number, Principal Investigator Name, and Operator Name.

DATA WILL BE STORED ON THE LOCAL HARD DRIVE FOR AT LEAST ONE MONTH. BACKUP WILL BE PERFORM WHEN INDICATED BY THE SOFTWARE PROGRAM (Appendix D).

5. Cleaning the DEXA unit

• The DEXA unit should be cleaned after each scan.
• Use a soft cloth to wipe surfaces. Use a mild detergent such as Palmolive Pure + Clear to remove dirt or debris.
• To clean the table pad, use a simple solution of neutral soap such as Palmolive Pure + Clear and warm water. Let it dry before scanning.
  • Do not remove the cover from the table pad.
• To disinfect the table pad, use a phenolic or quaternary type disinfectant such as Cavi-Wipes in the concentration recommended by the manufacturer.
  • Disinfectants applied at full or high concentration may damage the fabric.
  • Iodine-type disinfectants may result in staining.
• To clean accidental spills, immediately wipe the spill with a slightly dampened sponge.
  • If the spill penetrates the system’s interior, turn off power to the scanner immediately by pressing the ‘Off’ button on the table.
  • Let the table pad dry thoroughly before scanning.
• Turn on the power when the unit is thoroughly dry.

6. Emergency Procedures

• Power failure
  • Treatment:
    • Turn off all equipment. When the power returns, wait several minutes before turning on the equipment again. To shut down completely, turn off the computer and turn off the power switch on the table.
• Failure during operation
  • Treatment:
    • Press the red Emergency Stop Button on the control panel. The table and C arm immediately stop moving and the X-rays and laser turn off.
• Planned power outage
  • Treatment:
    • Turn off the computer, turn off the power switch on the table, and unplug the unit from the wall. When normal power resumes, plug the unit in, turn on the power switch on the table, and wait up to an hour to run QC and scan.

7. Maintenance and Technical Issues

• For technical problems call the Hologic service engineer or the Hologic help desk (1-800-321-4659).

8. Suggested Informed Consent Language

Dual Energy X-ray Absorptiometry (also known as DEXA Scan): DEXA measures your body composition. This procedure uses x-rays to produce precise, high-quality images of your body fat and muscles. Before the DEXA scan you will be asked some questions that will help the study team know that it is safe for you to have the scan. Once you are cleared for the DEXA scan you will be asked to remove jewelry, body piercings, clothing with zippers or metal buttons, and underwire bra, and to change into scrubs or a gown. You will need to lie flat on a table and be very still for about 6 minutes while the scan is performed. You will feel the table move while this is happening. There is no pain or discomfort associated with the scan other than lying still and flat. DEXA involves exposure to very low amounts of x-ray radiation. Radiation doses to our bodies are measured in a unit called the Sievert (Sv) or millisievert (mSv), where 1 Sv is equal to 1000 mSv. Every person is exposed daily to background radiation from natural sources like soil, rocks, radon, the sun, and outer space. On average, a person in the United States receives about 3 mSv per year from natural background radiation, or about 0.01 mSv per day. When a person receives radiation as part of a DEXA scan with this study, they receive between 0.01-0.04 mSv. That is, for each DEXA scan that you undergo you will receive radiation equivalent to about 1-4 days of natural background radiation. This amount of radiation is less than half of that of a chest x-ray and less than 1% of that of a CT scan. In total, you will receive [insert number] DEXA scan(s) during the course of this study. The total amount of radiation exposure received in this study is below the levels that are thought to result in a significant risk of harmful effects. One possible indirect health effect is an increase in the risk of cancer. The potential increase in the risk of cancer and potential increase in the risk of other adverse health problems from the low level of radiation used in this study are too small to be estimated accurately. You should not have a DEXA scan if there is any chance that you are pregnant, or if you had a barium swallow procedure, radioisotope injection, or a CT scan within the past 7 days.

Additional suggested language for protocols requiring a urine pregnancy test:

Additionally, if you are a female of childbearing age, you will be asked to take a urine pregnancy test immediately before your DEXA scan. The person performing the DEXA will obtain the results of the pregnancy test before administering the scan. If the test is positive, a scan will not be performed. We will inform you if your test is positive and you will be advised to contact your personal physician.

9. Suggested Assent Language

You will lie on a comfortable table for about 6 minutes while a scanner moves over your body. The scanner does not touch your body. You will not feel anything during the scan. Before the scan, we will tug on your ankles and place your arms at your side. The scanner will measure how much muscle, fat and bone you have in your body. During the test, the table will moves up and down.

References: User manual: Hologic Discovery QDR® Series Operator Manual, Document No. MAN-02645 Revision 001

Technical manual: Hologic QDR Series X-Ray Bone Densitometers Technical Specifications Manual, MAN-03283 Revision 003

Attachments: A: DEXA Scan Information & Waiver Form for Non-Research; B: DEXA Scan Tracking Log

Appendices: Appendix C- DEXA Partial Body Scan

Appendix D- DEXA Back-up Instructions

Approver: CTRU Medical Director

Click here to request attachments