91探花

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Figure 3, page 9 in the thesis. Histological sections of sentinel lymph node without (A) and with (B) macro-metastases in a patient with breast cancer.
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Nushin Mirzaei: Ultra-low dose of tracer identifies sentinel lymph node

Sentinel lymph node (SLN) staging is important for treatment in patients with melanoma and breast cancer. Superparamagnetic iron oxide (SPIO) is a relatively new tracer used to locate the SLN. Nushin Mirzaei鈥檚 doctoral thesis demonstrates that an ultra-low dose of SPIO still effectively identify SLN, significantly reducing side effects.

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Nushin Mirzaei, a surgeon specializing in breast cancer and melanoma surgery at Sahlgrenska University Hospital, and a doctoral candidate at the Institute of Clinical 91探花s.

NUSHIN MIRZAEI
Dissertation defense: 24 May 2024 (click for details)
Doctoral thesis:
Research area: Surgery
Sahlgrenska Academy, The Institute of Clinical 91探花s

The sentinel lymph node is the first lymph node to receive lymphatic drainage from a tumor area. This node is the first affected when cancer spreads.

Today, the sentinel lymph node is routinely removed in patients with conditions such as melanoma and breast cancer. This typically involves a dual technique: a radioactive tracer linked to a carrier protein and a blue dye to locate the sentinel lymph node.

However, the availability of radioactive tracers is limited, and the blue dye can rarely trigger allergic reactions.

Skin discoloration and artifacts

A new technique using an iron-based tracer, superparamagnetic iron oxide (SPIO), has shown comparable results to the dual technique.

鈥淒rawbacks of using SPIO in breast cancer include its potential to cause skin discoloration at the injection site and to induce artifacts in subsequent MRI scans,鈥 Nushin Mirzaei explains.

She is a surgeon specializing in breast cancer and melanoma surgery at Sahlgrenska University Hospital, currently pursuing her doctoral degree at the Institute of Clinical 91探花s.

Figure 2, page 7 in thesis. A: Blue dye injected intradermally at the borders of the previous excision scar in a patient with melanoma. B: Blue and brown sentinel lymph node in the right inguinal basin. Photo by Nushin Mirzaei, with the patient鈥檚 consent.

鈥淎 10鈥20 times lower dose鈥

What is the focus of your research?
鈥淭he recommended dose of SPIO for breast cancer is 1鈥2 milliliters injected into the breast. The primary aim of my thesis was to evaluate if it鈥檚 possible to use a 10鈥20 times lower dose, an ultra-low dose of SPIO at 0.1 milliliters, to still identify the sentinel lymph node in patients with melanoma and breast cancer. We also explored whether this could lead to reduced skin discoloration and MR artifacts,鈥 says Nushin Mirzaei, adding:

鈥淎dditionally, we investigated if MRI imaging after SPIO injection could identify metastases in the sentinel lymph node before surgery.鈥

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Cover image of the thesis. Carol Peace Sculpture, Coworth Park, Ascot. Photo by Nushin Mirzaei.

Only minor side effects

What are the key research findings?
鈥淚dentifying the sentinel lymph node with an ultra-low dose of SPIO tracer was feasible in patients with both melanoma and breast cancer. Our initial study also suggests the possibility of predicting tumor spread to the sentinel lymph node with MRI before surgery, which hasn鈥檛 been possible before.鈥

And what about the MR artifacts and skin discoloration?
鈥淭he ultra-low dose of SPIO caused only minor MR artifacts, which generally didn鈥檛 affect breast diagnostics. We observed only slight skin discoloration in some patients, who also reported no significant impact.鈥

鈥淎n enlightening research process鈥

What has been rewarding and challenging about your doctoral project?
鈥淚t has been enlightening to be involved in the entire research process. From writing ethical applications, informing and obtaining patient consent, coordinating and structuring follow-up checks to collaborating with all co-authors. Despite occasional challenges in data analysis, the atmosphere within the research team has been remarkably positive.鈥

Text: Jakob Lundberg