Seed Localization

Approximately 90-95% of all breast cancers lead to lumpectomy. Image-guided localization is required ~30% of the time and is performed at the time of biopsy. The utilization of radioactive seed insertion reduces surgeon re-excision and clear margin success rates.

The use of IGAR to deploy these seeds will increase accuracy while providing patient comfort with no uncomfortable wires exposed while waiting for surgery.

Seed Localization; Figure 1.  A radioactive seed being placed under x-ray guidance

Ann of Surg Oncol 2009 October 16(10) 2717-2730 Obtaining Adequate Surgical Margins in BCT in pts with early stage breast Cancer. Rick Pleijhuis

Dr. Peter Lovrics (R) operating at St. Joseph’s Hospital, Hamilton

Seed Localization Project

Dr Peter Lovrics, St Josephs Hospital & McMaster University

Although minimally invasive techniques are the preferred route for diagnosis, there are some cases where minimally invasive techniques cannot be used, and surgical removal is the only way to proceed. In cases where a lesion cannot be located by palpation (feeling of a physical “hard” lump) then the surgeon has to be guided to the correct location. This is typically done using very fine “hook wires” that are placed using x-ray or ultrasound directly into the breast where the anomaly is prior to surgery.

Dr Peter Lovrics (Head of General Surgery) has performed a clinical trial of a new technique called seed localization where a very small radioactive “seed” (smaller than a grain of rice) is placed near the area of interest prior to surgery (see Figure 1). In the operating theatre Dr Lovrics can locate the seed using a radioactive detector, and hence identify the lesion, which can be removed with much greater accuracy than the conventional hook-wire procedure. This has been proven to greatly reduce the possibility of follow up surgery.  It also allows the surgeon greater flexibility in their angle of approach to access the tumor (allowing better cosmesis) and can result in a smaller sample needing to be taken (greater accuracy).

With IGAR we have the ability to make the next step and use MRI guidance to place the seed in certain types of cancer that are invisible to ultrasound and x-ray mammography. We believe this will play a vital role for surgical guidance in excisional biopsy and breast conserving lumpectomy procedures.