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- Jazrawi, Allan
(författare)
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Optimizing the magnetic tracer technique for sentinel lymph node detection and tumour localization in breast cancer surgery
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Breast cancer is the most common form of cancer in women, and the primary treatment modalities are still breast-conserving surgery (BCS) and sentinel lymph node dissection (SLND) in most cases. Superparamagnetic iron oxide nanoparticles (SPIO) are gaining momentum as a tracer for sentinel lymph node detection. The aim of this thesis is to further refine the magnetic method and investigate its postoperative effects.Paper I: This feasibility study, involving 79 patients, explored the use of SPIO-guided Magnetic resonance imaging (MRI)-lymphography and magnetic-guided axillary ultrasound (MagUS) with core biopsy for sentinel lymph node (SLN) localization and SLN status. MagUS, outperformed baseline axillary ultrasound and successfully traced SLNs in all cases, detecting macro-metastases accurately and missed only one micro-metastasis. The findings suggest that the MagUS technique enables minimally invasive approach in axillary mapping that can meet tailored patient needs and reduce the need for diagnostic surgery. Paper II: This study aimed to compare skin staining incidence and size between different doses of SPIO and blue dye (BD), evaluating their persistence over time. Among 270 women receiving SPIO, 204 also received BD. At six months, 21.5% had SPIO stains and 25% had BD stains Incidence and size decreased reciprocally, with no significant difference between the tracers regarding skin staining after 24 months. Paper III: This study compared the magnetic technique using Magseed® for non-palpable breast tumor localization with guidewire localization and SPIO for sentinel lymph node detection. In a prospective analysis of 426 women, reoperation rates, resection ratios, and SLN detection were assessed. No significant differences were found between the techniques in terms of re-excisions, resection ratios, or SLN detection. However, the magnetic technique showed more successful localizations, shorter operation time, and better overall experience among surgeons, radiologists, and theater coordinators, making it a good alternative for BCS.Paper IV: In this prospective observational study, the impact of postoperative MRI outcome was explored in patients undergoing BCS with a peritumoral SPIO injection for SLN detection. The study affirms SPIO as a safe tracer for SLN detection without compromising MRI interpretation after BCS, ensuring reliable breast cancer recurrence assessment.
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| 2. |
- Hersi, Abdi-Fatah, 1989-
(författare)
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Superparamagnetic iron oxide nanoparticles, a novel tracer in breast cancer surgery
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The most common surgical choice of treatment in breast cancer is breast-conserving surgery (BCS) together with sentinel lymph node biopsy (SNB). Around 10% of breast cancer diagnosis are ductal carcinoma in situ (DCIS). Superparamagnetic iron oxide nanoparticles (SPIO) are a novel tracer for sentinel lymph node (SN) detection. The aim of this thesis was to investigate the unique applications and functionality of a magnetic approach in breast cancer surgery.Paper I was a two-centre pilot study of 32 patients with non-palpable breast cancer who were scheduled for BCS together with SNB. They received SPIO for SNB and a magnetic seed (Magseed®) for localization of the breast tumour. All 32 patients underwent microscopically radical resection and SNB was successfully performed in all included patients.Paper II was a multicentre prospective single-cohort study. It was a pre-planned interim analysis of 189 patients with “high-risk” DCIS who received SPIO at primary surgery but without performing SNB. If an invasive breast cancer was shown by the final histopathology report, the patient was scheduled for second surgery to undergo SNB. Because SPIO has a much longer half-life than the radioisotope, the magnetic signal at the second surgery was sufficient for detecting SNs; in fact, in patients with DCIS, it reduced from around 50% to 22%. Paper III was a multicentre prospective trial. Two consecutive cohorts of patients with breast cancer scheduled for SNB (n = 328) were included. Lower doses of a refined SPIO suspension were tested in different time frames and injection sites. Analyses were performed as a one-step individual patient-level meta-analysis using patient-level data from a similar previous cohort (n = 206) as a third reference group. In 534 patients, the SPIO SN detection rates were comparable (97.5% vs. 100% vs. 97.6%, p = 0.11) and were noninferior to the dual technique. Paper IV was a multicentre randomized pilot trial aimed to compare tumour localization in nonpalpable breast cancers using either Magseed® or guidewire in patients scheduled for BCS + SNB. All patients received SPIO for the SNB preoperatively. Patients who were randomized to the magnetic seed cohort received their Magseed® at the same time as the SPIO injection preoperatively while the guidewire placement was performed on the same day as surgery. In 207 patients, there were no significant differences in reoperation rate (3% in the magnetic seed cohort vs 7% in the guidewire cohort, p = 0.35).
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