Accurate axillary staging by superparamagnetic iron oxide-enhanced MRI at 1.5 T with fat-suppression sequence as an alternative to sentinel node biopsy in breast cancer

Advancing MRI with magnetic nanoparticles: a comprehensive review of translational research and clinical trials

The nexus of advanced technology and medical therapeutics has ushered in a transformative epoch in contemporary medicine. Within this arena, Magnetic Resonance Imaging (MRI) emerges as a paramount tool, intertwining the advancements of technology with the art of healing. MRI's pivotal role is evident in its broad applicability, spanning from neurological diseases, soft-tissue and tumour characterization, to many more applications. Though already foundational, aspirations remain to further enhance MRI's capabilities. A significant avenue under exploration is the incorporation of innovative nanotechnological contrast agents. Forefront among these are Superparamagnetic Iron Oxide Nanoparticles (SPIONs), recognized for their adaptability and safety profile. SPION's intrinsic malleability allows them to be tailored for improved biocompatibility, while their functionality is further broadened when equipped with specific targeting molecules. Yet, the path to optimization is not devoid of challenges, from renal clearance concerns to potential side effects stemming from iron overload. This review endeavors to map the intricate journey of SPIONs as MRI contrast agents, offering a chronological perspective of their evolution and deployment. We provide an in-depth current outline of the most representative and impactful pre-clinical and clinical studies centered on the integration of SPIONs in MRI, tracing their trajectory from foundational research to contemporary applications.

Intraoperative Imaging Techniques in Oncology

Imaging-based procedures have become well integrated into the diagnosis and management of oncological patients and play a significant role in reducing morbidity and mortality rates. Here we describe the established and upcoming surgical oncological imaging techniques and their impact on cancer management.

The Magnetic Technique-A Novel and Promising Method to Improve Axillary Staging Localisation from a Swedish Perspective

The magnetic technique using superparamagnetic nanoparticles of iron oxide has been well established for sentinel lymph node detection. Its main advantage is in the context of logistics, with the possibility to inject several weeks before surgery and the possibility to give access to sentinel lymph node biopsy for women worldwide in places without nuclear medicine facilities. We have not yet seen the full potential of this technique, and new implications have been developed for breast tumour localisation with paramagnetic clips and axillary staging after neoadjuvant chemotherapy using paramagnetic clips inserted in lymph node metastases before chemotherapy. In this report, we have presented our experience of the magnetic technique starting in 2014, and we have highlighted our current and future research directions.

Ultra-Low Dose of Superparamagnetic Iron Oxide Nanoparticles for Sentinel Lymph Node Detection in Patients with Breast Cancer

BACKGROUND

Sentinel lymph node (SLN) status is pivotal for treatment decision-making in patients with breast cancer. Superparamagnetic iron oxide nanoparticles (SPIO) have been shown to be equivalent to the dual technique with technetium99m (Tc99) and blue dye (BD) for SLN detection. The aim of this study was to determine the feasibility of detecting SLNs using an ultra-low dose of SPIO.

METHOD

Patients planned for breast conserving surgery and SLN biopsy were included. An intradermal injection of 0.1 mL SPIO was administered at the areolar border up to 7 days before surgery. Tc99/BD was administered according to clinical routine. SLNs were detected during surgery using a handheld magnetometer. All nodes with a magnetic and/or radioactive signal, as well as blue or clinically suspicious nodes, were harvested and analyzed.

RESULTS

In 50 patients, SPIO was injected a median of 4 days before surgery. At least one SLN was found in all patients with both methods. A total of 98 SLNs were removed; 90 were detected using SPIO and 88 using Tc99/BD. Of the 90 SLNs detected by SPIO, 80 were Tc99/BD positive (concordance 89%). Histopathological analysis classified 16 patients with tumor cells deposit and 9 with macro-metastasis > 2mm, where one SLN was identified only by the radioactive technique and one only by the magnetic technique.

DISCUSSION

SLN detection using 0.1 mL ultra-low dose SPIO injected intradermally was successful in all patients. A future analysis will determine whether the approach using an ultra-low dose of SPIO injected intradermally will minimize skin staining and MRI artefacts.

Advanced diagnostic imaging of sentinel lymph node in early stage breast cancer

Sentinel lymph node biopsy has been regarded as the standard procedure for early staging breast cancer. One of the key steps is to locate the sentinel lymph node (SLN). The recommended method is the joint use of blue dye and radioisotope. However, due to radionuclide radiation and high cost, it is urgent to develop more convenient and sensitive imaging methods to accurately locate SLN. This article discusses the advancement of accurately locating SLN by isotope tracer imaging, magnetic tracer method, computed tomographic lymphography, and trans-lymphatic contrast-enhanced ultrasound, as well as proposing new propose for clinical diagnosis.

Sentinel lymph node localization and staging with a low-dose of superparamagnetic iron oxide (SPIO) enhanced MRI and magnetometer in patients with cutaneous melanoma of the extremity - The MAGMEN feasibility study

BACKGROUND

In patients with melanoma, sentinel lymph node (SLN) status is pivotal for treatment decisions. Current routine for SLN detection combines Technetium^99m (Tc⁹⁹) lymphoscintigraphy and blue dye (BD). The primary aim of this study was to examine the feasibility of using a low dose of superparamagnetic iron oxide (SPIO) injected intracutaneously to detect and identify the SLN, and the secondary aim was to investigate if a low dose of SPIO would enable a preoperative MRI-evaluation of SLN status.

METHODS

Patients with melanoma of the extremities were eligible. Before surgery, a baseline MRI of the nodal basin was followed by an injection of a low dose (0.02-0.5 mL) of SPIO and then a second MRI (SPIO-MRI). Tc⁹⁹ and BD was used in parallel and all nodes with a superparamagnetic and/or radioactive signal were harvested and analyzed.

RESULTS

Fifteen patients were included and the SLNB procedure was successful in all patients (27 SLNs removed). All superparamagnetic SLNs were visualized by MRI corresponding to the same nodes on scintigraphy. Micrometastatic deposits were identified in four SLNs taken from three patients, and SPIO-MRI correctly predicted two of the metastases. There was an association between MRI artefacts in the lymph node and the dose SPIO given.

DISCUSSION

It is feasible to detect SLN in patients with melanoma using a low dose of SPIO injected intracutaneously compared with the standard dual technique. A low dose of SPIO reduces the lymph node MRI artefacts, opening up for a non-invasive assessment of SLN status in patients with cancer.