Use of radioactive seeds for the preoperative localization of non-palpable breast tumours

Breast cancer is the cancer with the highest incidence among women in Canada. The breast cancer screening programs offered across the country have contributed to detecting cancers at early stages. Very often, these cancers are not palpable and may be detected only with imaging tests such as a mammogram. Surgery to excise a non-palpable tumour requires the preoperative step of locating the tumour by a radiologist, who inserts a marker into the tumour site. The use of the metal hookwire as a marker is the current standard of treatment, even though it has been associated with a number of disadvantages.

The technology of radioactive seed localization was developed in the early 2000s. It involves implanting a small radioactive seed, originally designed for the treatment of prostate cancers (low-dose-rate brachytherapy). This seed emits a radioactive signal detectable by a gamma probe that the surgeon uses to locate the seed and therefore the tumour. This technology could make up for some of the disadvantages of wire localization.

Radioactive seed localization for non-palpable breast tumours has sparked interest in the medical field in Québec. That is why the Direction générale de cancérologie (DGC) asked the Institut national d’excellence en santé et en services sociaux (INESSS) to review the relevant literature on the effectiveness and safety of this method compared with wire localization.