Jacky Luiten

Iodine seed ‐ versus wire ‐ guided localization in breast ‐ conserving surgery for non ‐ palpable DCIS | 87 6 Introduction Improved imaging techniques in combination with nationwide mammographic screening have led to increased detection rates of ductal carcinoma in situ (DCIS). 1 ‐ 3 The majority of non ‐ palpable DCIS lesions discovered in breast cancer screening programs are identified by the presence of microcalcifications on mammograms. In contrast to invasive breast cancer, DCIS is often diffusely spread and the margins are therefore less discrete. 4 Consequently, surgical removal of DCIS is more often associated with incomplete resection than invasive breast cancer. 5 Accurate preoperative localization of the lesion is essential to enable adequate surgical resection of non ‐ palpable DCIS. 6 Wire ‐ guided localization (WGL) of non ‐ palpable invasive breast tumors or DCIS is currently the most frequently used technique. 7 To locate the lesion, a hook wire is placed under ultrasound or stereotactic guidance by a radiologist before surgery. Subsequently, the surgeon can excise the lesion guided by the wire. In recent years, an alternative localization technique has been developed for non ‐ palpable breast lesions, which can also be used to mark the cancer area in patients receiving neoadjuvant chemotherapy before the start of treatment. 8 , 9 This technique consists of the implantation of a slightly radioactive iodine ‐ 125 seed. The aim of the present study was to compare the efficacy of iodine ‐ 125 seed ‐ guided localization (I ‐ 125 GL) and WGL for localization of non ‐ palpable DCIS. Methods Between March 2006 and June 2013, 945 women were diagnosed with non ‐ palpable invasive cancer or DCIS. Only patients with pure DCIS, on both preoperative core biopsy and definitive pathology, were included in the present study. Furthermore, only lesions localized by either I ‐ 125 GL or WGL were analyzed. Patients with DCIS excised by the radioguided occult lesion localization technique were not included owing to small numbers ( n =3). 6 Approval for this study was provided by the local ethics committee of Amphia Hospital. Endpoints The primary endpoint was complete resection of the DCIS lesion on final pathology. According to Dutch guidelines for the treatment of breast cancer, the status of the resection margins is defined by the extent of the tumor ‐ free resection margin 10 . Focally involved margins are defined by tumors extending to the inked resection