Exploring an Alternative Pre-operative SLN Mapping Method Using a Magnetic Tracer and MRI for Melanoma Patients

Sentinel lymph node biopsy (SLNB) is crucial in the management of malignant melanoma treatment and is currently performed by pre-operatively inject a colloid nanomaterial labeled with Technetium (99mTc) as radioactive tracer. Intra-operatively, Patent Blue (PB) will be injected to improve the visualization of the lymphatic tract. However, current pre-operative SLN mapping technique is associated with disadvantages as radiation exposure for both patients and health care staff and logistic challenges, because of time constraints due to short half-live time of 99mTc. Superparamagnetic iron oxide (SPIO) is a non-radioactive technique using a magnetic tracer (Magtrace® (Endomagnetics Ltd.)) to identify SLNs. Several studies showed that SPIO is non-inferior to dual tracing with 99mTc and PB in breast cancer patients. SPIO is expected to be non-inferior to dual tracing with 99mTc and PB in melanoma patients. However, further research is needed to demonstrate the use of SPIO in pre-operative MRI scanning. The primary objective of this study is to evaluate the feasibility and diagnostic accuracy of pre-operative MRI scanning using SPIO compared to lymphoscintigraphy (LS) and single-photon emission computed tomography/computed tomography (SPECT/CT) using 99mTc for identifying SLN status in melanoma patients.