+ 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
- 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 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).
- American College of Radiology and the Society of Nuclear Medicine. ACR-SNM Technical Standard for Diagnostic Procedures Using Radiopharmaceuticals. Available at: http://interactive.snm.org/docs/ACR-SNM_Technical_standards_for_diagnostic_procedures_using_radiopharmaceuticals.pdf. Accessed March 20, 2013.
- Society of Nuclear Medicine. Performance and responsibility guidelines for the nuclear medicine technologist (Rev 2003). Available at: http://interactive.snm.org/docs/pg_ch16_0803.pdf. Accessed March 20, 2013.
- 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.
- Australian Radiation Protection and Nuclear Safety Agency. Safety Guide: Radiation Protection in Nuclear Medicine. Available at: http://www.arpansa.gov.au/pubs/rps/rps14_2.pdf. Accessed March 20, 2013.