Quantitative assessment of the radiation hazards and risks in sentinel node procedures

Sentinel node localization using an injected radiopharmaceutical and a gamma probe is performed in many hospitals. Employers have a duty to give appropriate training to staff who may not have been previously formally trained to work with unsealed radioactive sources. A study was performed to assess hazards and risks at all stages of the localization procedure. Whole body doses and finger doses of imaging, surgery and pathology staff were determined. The activity remaining in the tumour specimen, excised nodes and disposable waste from the operating theatre was measured. Any radioactive contamination of the operating theatre and equipment was also ascertained. All results were then assessed in light of current UK radiation protection legislation for the protection of staff and members of the public. Results showed that radiation doses are low and no additional procedures are required for protection of staff, provided the usual procedures for biohazards are in place. However, an information sheet has been prepared for the reassurance of staff, and theatre swabs may need to be stored temporarily before disposal. Injecting and imaging on the day before surgery is preferred, compared with injecting and imaging before surgery on the same day, since this gives lower radiation doses to staff, lower activity in excised specimens and waste, and provides a higher count rate giving better image quality.