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Accountability for accurate dose to patient (NM specific)


MRTs ensure radiopharmaceutical doses are appropriate and accurate


+ Importance of accurate dosing

  • An accurate dose is defined as one that falls within the limits of ± 10% of the prescribed dose
  • Accurate radiopharmaceutical dose is important for:
    • Quality of the procedure
    • Reproducibility
    • Patient safety


  • The dose of radiopharmaceutical administered to the patient is a reflection of the balance between optimal study and patient safety.   
    • Dose is kept as low as reasonably achievable (ALARA) to obtain the optimal diagnostic/therapeutic outcome for the patient
    • Administration of a dose below the minimum of the recommended range for a procedure can lead to a suboptimal study
    • Administration of a dose above the maximum of the recommended range does not correlate with improvements in study outcomes or diagnostic information in most circumstances

+ MRT responsibilities

  • MRTs always assay radiopharmaceuticals prior to administration to patients to ensure the dose being given to the patient is accurate for the study proposed, including:1,2
    • The quantity of radioactivity to be administered reflects the dose prescribed (either individually by prescription or in a standard protocol)1
    • Radioactive decay calculations confirm the volume necessary to deliver the prescribed radioactive dose2


  • MRTs ensure a radiopharmaceutical is not being used beyond the manufacturer’s recommended expiration date/time unless specific quality control testing demonstrates that the product still meets applicable specifications at the time of use.3
  • The dosage of radiopharmaceuticals given in therapeutic procedures should be verified by a second MRT or physician prior to administration.4
  • MRTs follow dose charts to make adjustments to dose based on patient factors:
    • Patient body habitus (usually ±10% of prescribed dose)
    • Pregnancy (lower dose for pregnant women)
    • Doses reduced for pediatric patients based on weight (taking into consideration department-set minimums for pediatric patients)

+ Documentation

  • Documentation in the patient’s record includes:1,2
    • Study performed
    • Date and time
    • Radiopharmaceutical administered
    • Administered dose
    • Route/site of administration
    • Difficulties encountered (e.g., interstitial administration)


  • It is the MRT's responsibility to document/report inaccurate dosing (by themselves or by others) that they are aware of through the appropriate mechanisms (also see Patient safety incident reporting guideline for more information).

+ References

  1. American College of Radiology and the Society of Nuclear Medicine. ACR-SNM Technical Standard for Diagnostic Procedures Using Radiopharmaceuticals. Available at: Accessed March 20, 2013.
  2. Society of Nuclear Medicine. Performance and responsibility guidelines for the nuclear medicine technologist (Rev 2003). Available at: Accessed March 20, 2013.
  3. Callahan RJ, Chilton HM, Ponto JA, et al. Procedure Guideline for the Use of Radiopharmaceuticals 4.0. J Nucl Med Technol 2007;35(4):272-275.
  4. Australian Radiation Protection and Nuclear Safety Agency. Safety Guide: Radiation Protection in Nuclear Medicine. Available at: Accessed March 20, 2013.



October 16, 2013


Canadian Association of Medical Radiation Technologists
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phone: 613 234-0012 / 800 463-9729
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