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Pre‐procedural considerations

Within a controlled area

The entrance to the controlled area must be marked with a warning sign. Information is displayed to indicate the following.
  • The radioactive material and activity administered.
  • That only essential nursing procedures should be carried out and unnecessary time must not be spent near the patient while the sign is displayed.
Appropriate barriers, that is lead shields, should be placed at the entrance to:
  • prevent inadvertent entry by unauthorized personnel
  • reduce radiation exposure to staff and visitors.
Patients treated with unsealed radioactive sources should be confined to their rooms. The exception would be for special medical or nursing procedures when they must be accompanied by suitably trained staff (e.g. when having a whole‐body I‐131 scan post treatment).
Decon 90™ should be available in a controlled area. Decon 90™ is an approved solution for neutralizing radiopharmaceuticals in the event of a spillage. The solution should be diluted according to manufacturer's instructions or be available as ready‐to‐use wipes. Once the spillage area has been initially wiped with absorbent paper/pads, Decon 90™ is used to clean the surface. The area is then monitored to check for radiation contamination. The process should be repeated until the contamination has been reduced to a safe level (DH [15]). In the event of any spillage medical physics should be notified immediately to assess and advise.

Equipment

Thermoluminescent dosimeter (TLD)

A TLD measures a person's exposure to radiation and must be worn always when on duty (see Figure 24.5). A digital dosimeter should be used when ongoing immediate dose records are required.

Use of a contamination monitor

Waste and equipment must be monitored before being removed from any controlled area where patients have received or are receiving unsealed or sealed sources. This monitoring will establish if contamination has occurred or a sealed source is present amongst the items being removed (Hart [25]).
Before using a contamination monitor (see Figure 24.6 and Figure 24.1) it is important to check that the monitor's batteries are fully charged; the background reading on the monitor must then be noted before undertaking the monitoring. The background must be reasonably low (normally less than 10 counts per second) otherwise it will be difficult to detect small levels of radioactivity present on the item being monitored. If the background reading immediately outside the treatment room is found to be high, it will be necessary to monitor the items further away where the background is lower.
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Figure 24.1  Hand‐held contamination monitor. Source: Dougherty and Lister ([16]).
Items should be monitored by passing the monitor's probe over each item while watching for fluctuations in the count rate. If an item is found to be contaminated (indicated by a sustained increase in count rate), it should either be returned to a safe location in the treatment room or set aside in a designated area while help is sought from the medical physics department (Bomford [7]).
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