Same-day lymphoscintigraphy and sentinel node biopsy for early breast cancer

Lymphoscintigraphy and sentinel node biopsy are currently being assessed as an alternative to axillary dissection for staging in early breast cancer. However, little is known about the optimum timing of surgery following injection of the radio-isotope into the breast. The aim of the present study was to establish whether lymphoscintigraphy on the morning of surgery allowed efficacious and accurate sentinel node identification and biopsy.

We reviewed our experience of 216 consecutive cases of lymphoscintigraphy in early breast cancer using peritumoural injections of technetium99m antimony sulphide colloid and subsequent sentinel node biopsy using a hand-held gamma probe and blue dye. The time interval between radioisotope injection and successful intraoperative identification of the sentinel node was assessed and whether this was associated with certain clinical and histological variables.

The sentinel node was identified by lymphoscintigraphy in 160 cases (74%) at a median time duration of 40 min post injection. The median time duration between isotope injection and surgery was 5 h. Of the 160 cases where the sentinel node was visualized at lymphoscintigraphy, sentinel node biopsy was successfully performed in 155 cases (97%). This compares with 25/56 (45%) cases where lymphoscintigraphy failed to localize the sentinel node (P < 0.0001). There was no association found between the injection of the radioisotope greater or less than 5 h before surgery and the successful intraoperative identification of the sentinel node. Failure to identify the sentinel node at lymphoscintigraphy beyond 3 h was associated with a low intraoperative identification rate. There was no correlation found between intraoperative identification of the sentinel node according to the duration of isotope injection in relation to surgery and the various clinical and histological factors assessed.

In our experience, the chance of identifying the sentinel node at the time of surgery does not increase with longer isotope injection duration using technetium99m antimony sulphide colloid. As soon as a sentinel node is identified at lymphoscintigraphy, one can proceed to surgery. Scanning beyond 3 h does not appear to be effective in sentinel node localization. Given that the median time for successful lymphoscintigraphic mapping was only 40 min, lymphoscintigraphy can easily be completed during the morning to allow surgery to take place the same day.