Radiation-guided breast sentinel lymph node biopsies - is a handling delay for radiation protection necessary?

Radiation-guided sentinel lymph node (SLN) biopsy is a well-established procedure in many countries. However, histopathology protocols in different centres specify widely differing sample handling delays of between 0 and 72 h. Introducing a delay reduces the radiation exposure of pathologists, but has a detrimental effect on the quality and validity of histology. This study aims to show that a sample handling delay is not justified by the radiation doses to pathologists handling samples received directly from surgery.

Radiation doses to the body and hands of pathologists handling samples delivered directly from theatres were measured using personal dose meters. These measurements were supplemented by dose assessments undertaken using dose-rate measurements at 1 cm and 30 cm from Tc-99m sources to simulate the processing of samples. The study has shown that radiation doses arising from a zero delay in sample handling represent a negligible radiation risk to pathologists and are well within relevant limits specified in the Ionising Radiations Regulations 1999.

This study supports adoption of a zero-delay SLN histopathology protocol. Centres must, however, complete a risk assessment that accounts for local practice and adopt simple precautions to keep doses to pathologists as low as reasonably achievable.