Magnetic Resonance Sentinel Lymph Node Imaging and Magnetometer-Guided Intraoperative Detection in Penile Cancer, using Superparamagnetic Iron Oxide Nanoparticles: First Results

Abstract

In penile cancer, lymph node (LN) metastasis is the main known prognostic factor that affects survival. Inguinal sentinel LN (SLN) dissection (sLND) using radioactive marking is recommended by the European Association of Urology guidelines to evaluate the nodal status in clinically nodenegative penile cancer (cN0; ≥pT1, G2). Dependence on radioisotopes limits the application of this procedure to small parts of the developed world, and imposes restrictions on hospital logistics. To overcome these issues, SLN visualization using magnetic resonance imaging (MRI) and magnetometer-guided detection after intraprostatic injection of superparamagnetic iron oxide nanoparticles (SPION) has been successfully applied in prostate cancer. Here, we present the first results of magnetic sLND in penile cancer. After peritumoral SPION injection, MR SLN imaging and magnetometer-guided sLND were performed in one cN0 penile cancer patient. Another patient underwent magnetometerguided sLND only. In the first case, 5 SLNs could be visualized on MRI and intraoperatively detected by magnetometer-guided sLND. In the second patient, 3 SLNs could be detected by magnetic sLND. Neither patient exhibited adverse events attributable to SPION-injection. In conclusion, SPIONguided SLN identification using MRI and a handheld magnetometer is feasible and could provide a radiation-free technique for SLN identification in penile cancer. For further clarification, a multicenter study should be carried out.

Optimizing Dose and Timing in Magnetic Tracer Techniques for Sentinel Lymph Node Detection in Early Breast Cancers: The Prospective Multicenter SentiDose Trial

“…In a large patient dataset, it is now shown that a reduction down to half of the stipulated dose is highly effective and that a deeper preoperative injection yields more SLNs while retaining a high SPIO-RI concordance rate and resulting in less skin staining, when injected peritumorally. The use of SPIO in other clinical situations, such as SLN identification and dissection in malignant melanoma [31], prostate cancer [32][33][34], penile cancer [35] and uterine cancer [36], has been investigated, with interesting implementations.…”

Accuracy of Magnetometer-Guided Sentinel Lymphadenectomy after Intraprostatic Injection of Superparamagnetic Iron Oxide Nanoparticles in Prostate Cancer: The SentiMag Pro II Study

“…Initial studies on the magnetic sentinel method have also been carried out on several other tumor entities, which are to be continued in a comparable manner. Recently, the feasibility of intraoperative magnetic SLN identification using the SentiMag system in penile cancer patients could be shown in two pilot studies [14,28]. In addition, our working group was able to demonstrate the visualization of SLNs using MRI after peritumoral SPION injection in penile cancer [14].…”

“…After the successful application of the magnetometer-guided sentinel approach in breast cancer, the feasibility and safety of intraoperative detection of SPION-marked SLNs using a handheld magnetometer following intraprostatic SPIONs injection was demonstrated in PCa [13]. Currently, the use of this magnetic sentinel procedure is also being investigated in other tumor entities, for example, initial positive results have recently been shown for penile cancer [14].…”

“…Recently, the feasibility of intraoperative magnetic SLN identification using the SentiMag system in penile cancer patients could be shown in two pilot studies [14,28]. In addition, our working group was able to demonstrate the visualization of SLNs using MRI after peritumoral SPION injection in penile cancer [14]. Klimczak et al compared the efficacy and safety of SLN detection in eight vulvar cancer patients using the SentiMag system with the standard radioactive tracer and reported a high detection rate (100%) and complete concordance to the standard procedure [29].…”

Accuracy of Magnetometer-Guided Sentinel Lymphadenectomy after Intraprostatic Injection of Superparamagnetic Iron Oxide Nanoparticles in Prostate Cancer: The SentiMag Pro II Study

“…After the successful application of sentinel diagnostics in breast cancer, the feasibility and safety of intraoperative detection of SLNs using intraprostatic SPION injection and a handheld magnetometer was demonstrated in PCa [9]. Currently, the use of this magnetic sentinel procedure is also being investigated in other tumor entities; for example, initial positive results have recently been shown for penile cancer [10]. detected by sLND might already be connected downstream [17].…”