Finger doses due toGa-labelled pharmaceuticals in PET departments-results of a multi-centre pilot study.

Introduction: Although the use ofGa has increased substantially in nuclear medicine over the last decade, there is limited information available on occupational exposure due toGa. The purpose of this study is to determine the occupational extremity exposure during the preparation, dispensing and administration ofGa-labelled radiopharmaceuticals.

Method: Workers in eight centres wore a ring dosimeter for all tasks involvingGa-labelled radiopharmaceuticals for a minimum of one month. Additionally, the fingertip dose was monitored in two centres and the hand with the highest ring dose duringGa procedures was also identified in one centre.

Results: The median normalised ring dose forGa procedures was found to be 0.25 mSv GBq(range 0.01-3.34). The normalisedGa ring doses recorded in this study are similar to that found in the literature forF. This study is consistent with previous findings that the highest extremity dose is found on the non-dominant hand. A limited sub study in two of the centres showed a median fingertip to base of the finger dose ratio of 4.3. Based on this median ratio, the extrapolated annualGa fingertip dose for 94% of the workers monitored in this study would be below Category B dose limit (150 mSv) and no worker would exceed Category A dose limit (500 mSv).

Conclusion: When appropriate shielding and radiation protection practices are employed, the extremity dose due toGa is comparable to that ofF and is expected to be well below the regulatory limits for the majority of workers.