Use of the Sentimag® guidance system in East Africa

Since May 2021, Dr Marek Ostrowski, a consultant oncoplastic breast surgeon in Nairobi, Kenya, has been using the Sentimag® guidance system to accurately localise lymph nodes and tumours in surgery.

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Lymph node surgeryfor breast cancer

When breast cancer spreads, it typically goes first to nearby lymph nodes under the arm. Assessment of the lymph nodes is therefore essential in the treatment. To help find out if the cancer has spread outside the breast, one or more of the lymph nodes under the arm (axillary lymph nodes) are removed and checked in the laboratory. Anyone with invasive breast cancer will have the lymph nodes under the arm assessed. The outcome of this helps the medical team to recommend the optimal treatment pathway.

Lymph node assessment

Historically, in women diagnosed with breast cancer, all of the axillary lymph nodes were removed together with the whole breast. This was done for two reasons: to help stage the breast cancer and to help prevent a regional recurrence of the disease.

However, removal of multiple lymph nodes at the same time increases the risk of harmful side effects, and now guidelines recommend removal of the sentinel lymph nodes (first lymph node to which cancer cells are most likely to spread) only.

The sentinel lymph node biopsy procedure

Sentinel lymph node biopsy (SLNB) is the most common and least invasive way of checking the lymph nodes. Lymph node surgery is often done as part of the main surgery to remove the cancer, but in some cases, it might be done as a separate operation.

In a SLNB, the surgeon finds and removes the first lymph node(s) to which the cancer is likely to spread. To do this, usually the surgeon injects a radioactive tracer and a blue dye into the area around the tumour. Lymphatic vessels will carry these substances along the same path that the cancer would take. The sentinel node will be the first lymph node(s) the substances travel to, indicating to the surgeon which nodes to remove.

SLNB reduces the possible long-term effect of lymph node surgery, such as lymphoedema.

The Sentimag® guidance system

I was the first surgeon in the East African region to use the Sentimag® guidance system and the innovative Magtrace® lymphatic tracer, a liquid that provides an alternative way to flexibly and accurately detect sentinel lymph nodes. It offers patients the highest standard of breast cancer staging without the need for radioactivity and blue dyes, which can come with complications, such as supply and anaphylaxis.

The Sentimag® guidance system also allows medical professionals to mark small breast cancers or cancerous lumps before neoadjuvant chemotherapy. The Magseed® marker is a tiny seed designed to accurately mark the site of a cancer and help with its removal in surgery.

Detected by the Sentimag® localisation system and indicated for long-term implantation in any soft tissue, it enables more flexible and precise tumour localisation during surgery.

The Magseed® marker can be placed days, weeks or months ahead of surgery. The procedure is simple and completed in a matter of minutes.

Magseed® is used to localise large cancers in patients with planned neoadjuvant chemotherapy too. It allows the surgeon to find the area of previous abnormality after the cancerous lesion shrinks or disappears during presurgical treatment.

Plus, Magseed® plays an important role in localising cancerous lymph nodes in the armpit as well. Once a biopsy is taken, proving abnormality, these lymph nodes are marked by a Magseed® and easily identified during surgery after chemotherapy as part of the axillary assessment. Similar to the procedure of SLNB, this technique reduces the risk of post-treatment complications, such as lymphoedema and cording.

Breast cancer in Kenya

In Kenya, newly diagnosed breast cancer cases often present with one or two metastatic axillary lymph nodes. Magseed® is currently the only available marker to localise the lymph nodes. The seed is seen on ultrasound scan and often the excision can be performed under ultrasound guidance.

There is only one University Hospital which provides nuclear medicine services and isotope-based sentinel node biopsy. The same organisation offers stereotactic cancer localisation.

However, in the local setting, both Magtrace® and Magseed® can be used in small hospitals without the full range of nuclear medicine services. Magseed® makes localisation easier and is available everywhere at a much more affordable cost.

Dr Mariusz Marek Ostrowski (MD, PhD, FEBS) (Breast), is a consultant oncoplastic breast surgeon practicing in Nairobi, Kenya. He has worked as a consultant surgeon in Poland and the UK for over 10 years. He is committed to improving breast cancer screening and early diagnosis in East Africa.

MEET THE EXPERT – Dr Mariusz Marek Ostrowsk

Dr Mariusz Marek Ostrowski (MD, PhD, FEBS) (Breast), is a consultant oncoplastic breast surgeon practicing in Nairobi, Kenya. He has worked as a consultant surgeon in Poland and the UK for over 10 years. He is committed to improving breast cancer screening and early diagnosis in East Africa.

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