Introduction: The higher penetrating ability of 511kev photons emitted by PET radionuclides combined with the long duration of the studies raises concern that NMTs receive higher radiation exposure levels while working with PET patients. Previous studies found the greatest exposure occurred while injecting the patient. This study aimed to determine the stage in the PET study with the highest radiation exposure to a NMT.

Method: A Polimaster PM 1604A personal dosimeter was worn by one of the researchers whilst working alongside a NMT. 20 PET procedures were monitored over a four-day period. The average administered activity of F18-FDG was 332MBq. Stages identified for measurement included: observing patient injection, escorting the patient to the toilet, setting-up the patient for the scan and escorting them to the change room. The time spent and the cumulative equivalent dose (CED) at each stage were recorded for each patient.

Results:
Measurement Stage : Avg Time(min) : Avg CED(uSv)
- Observing patient injection : 1.8 : 0.26
- Escorting patient to toilet : 1.2 : 0.39
- Setting patient up for scan : 7.0 : 1.93
- Escorting patient to change room : 1.8 : 0.42
- Total for all stages : 11.8 : 3.00

Discussion: This study found that 65% of a NMTs radiation exposure from a PET procedure occurred during scan setup, in proportion to their time spent with the patient. Strategies need to be implemented in PET departments to help minimise the exposure to NMTs during each stage of a PET study.