Radiation dose to the hands increases for nuclear medical personnel

Average development of whole body and partial body dose (hand) between 1997 and 2021

Medications containing radioactive substances allow the examination of various organs such as the thyroid gland and heart muscle and help to find or combat tumours. The range of radioactive materials used and the possible applications is continually expanding. How does this trend affect the radiation dose to the medical personnel carrying out the examinations and treatments? A team of scientists led by the Federal Office for Radiation Protection (BfS) has investigated this question.

For their investigation, the researchers used data from the National Dose Register (in German "Strahlenschutzregister", SSR) of the BfS. In the register, the BfS records the radiation doses to everyone in Germany who is subject to occupational radiation protection monitoring. In 2021, this amounted to about 418,000 people from a wide range of occupational groups. Of these, around 11,400 were registered in the nuclear medicine category (i.e. the medical discipline that works with radioactive drugs).

Mostly no or low radiation doses

When evaluating the data, the researchers concentrated on the years 1997–2021. In the nuclear medicine category, just over half of those monitored for radiation protection were exposed to no (or no measurable) radiation dose during this period. Most people who were exposed to radiation had low values. However, exceedances of the legal limit values were registered in some cases.

A more accurate temporal analysis of the radiation doses detected revealed two opposing trends. The average whole body dose (effective dose) per person decreased noticeably – from 1.4 millisieverts per year (mSv/a) at the beginning of the evaluation period to 0.75 mSv/a at the end. The partial body dose (organ equivalent dose) to the hand also increased steadily. In 1997, the average figure was 11.1 mSv/a and person; in 2021, the average figure was 29.5 mSv/a.

Reduce the radiation dose to the hands in clinical practice

According to the scientists, during the study period, the average whole body dose decreased as a result of the continuous optimisation of occupational radiation protection over the past decades. They see several possible explanations for the increase in the average partial body dose to the hands. For example, the causes could be a poor radiation protection culture or the fact that larger quantities of radioactive substances are handled. The researchers recommend that regulatory authorities, radiation protection officers, and medical personnel carefully monitor this development and investigate the possible causes.

Various aids for shielding medical personnel from radiopharmaceuticals

It is expected that the use of radioactive drugs and the amount (activity) of the substances used will continue to increase. The researchers therefore recommend that in clinical practice, even more stringent measures to reduce the dose to the hands should be taken. In addition to technical measures, regular risk assessments, workplace inspections using check-lists, and preparatory training with non-radioactive substances are important before working with radioactive drugs.

Complete evaluation in the Journal of Radiological Protection

The study was published in the Journal of Radiological Protection. In addition to the radiation dose to nuclear medical personnel, the scientists analysed the radiation doses that people working in the production and delivery of radioactive substances were subject to. Again, the average whole body dose decreased. There was no clear trend for the partial body dose to the hand.