Magnetic detection of sentinel lymph node in papillary thyroid carcinoma: The MAGIC-PAT study results

Abstract

Introduction: Despite the controversy concerning sentinel lymph node biopsy (SLNB) in papillary thyroid carcinoma (PTC), successful detection rates can be achieved by radioguidance and vital dyeing. However, the drawbacks in both techniques are notable. Magnetic-guided SLNB (mSLNB) using superparamagnetic iron oxide (SPIO) nanoparticles is appealing as an alternative procedure. Materials and Methods: mSLNB using the Sentimag-Sienna System ® , total thyroidectomy and central compartment dissection (CCD) were performed on all PTC patients. Lymph node involvement was assessed by postoperative pathological examination. Results: From 2014 to 2016, 33 consecutive patients with PTC were enrolled in the study. A total of 20 patients met the eligibility. mSLNB succeeded in 16 patients, with a detection rate of 80%. A median of two SLN per patient were detected. A median of 10.5 non-sentinel lymph nodes (NSLN) from CCD were examined. Among the patients, 56.25% (9/16) had no metastatic nodes, while 12.5% (2/16) had exclusively SLN involvement. No false negative cases were found. The agreement between SLN and NSLN status was 87.5%. The prediction of NSLN involvement by SLN status showed 100% sensitivity, 81.8% specificity, 71.4% PPV and 100% NPV. Subsequently, mSLNB and the final pathological analysis would discriminate 43.75% (7/16) of patients who would certainly benefit from CCD whilst 56.25% of the total would confirm an unnecessary lymphadenectomy and avoid morbidity. Conclusion: mSLNB showed satisfactory performance in PTC with clinical-negative nodes. We have shown mSLNB to be a good predictor of central compartment status that can improve the staging and management of PTC patients.

Magnetometer-Guided Sentinel Lymph Node Dissection in Prostate Cancer: Rate of Lymph Node Involvement Compared with Radioisotope Marking

“…Our analyses revealed high accordance between nomogram-based predictions and LNI rates in both sPLND techniques. These results suggest that magnetometer-guided sPLND is a reliable and promising alternative that can be used in PCa to overcome the disadvantages of radioisotope marking [ 26 , 27 ], as observed in other tumor entities [ 26 , 28 , 42 , 43 , 44 , 45 ]. Furthermore, an improved flow of the magnetic tracer may lead to an increased number of detected SLNs in magnetometer-guided sPLND, as observed in the present study.…”

Sentinel lymph node biopsy in thyroid cancer – literature review

“…Using this method, the Spanish surgeons detected a median number of two sentinel nodes/patient, while the ratio of metastatic nodes was of 31%; among the retrieved non-sentinel nodes, the ratio of positive nodes was 10.2%, all cases of positive non-sentinel nodes being found among patients with positive sentinel nodes. Therefore, the authors demonstrated that the sensitivity of the method was 100%, the specificity was 81.8%, while the accuracy was 87.5%, underlining in this way the effectiveness of the method (18).…”

“…A more recent study conducted by Fustegueras et al (18) on 20 patients with papillary thyroid carcinoma demonstrated the utility of magnetic guided sentinel node biopsy using superparamagnetic iron oxide, a tracer which has been used in the last two decades as an intravenous contrast agent for magnetic resonance imaging studies (19). Using this method, the Spanish surgeons detected a median number of two sentinel nodes/patient, while the ratio of metastatic nodes was of 31%; among the retrieved non-sentinel nodes, the ratio of positive nodes was 10.2%, all cases of positive non-sentinel nodes being found among patients with positive sentinel nodes.…”

A Comprehensive Grading System for a Magnetic Sentinel Lymph Node Biopsy Procedure in Head and Neck Cancer Patients

“…A magnetic SLNB is proposed as an alternative for a radioactive SLNB in, e.g., breast cancer [10,11], prostate cancer [12], and, more recently, for thyroid carcinoma [13] and oral cancer [14,15]. The magnetic SLNB utilizes a magnetic tracer (superparamagnetic iron oxide (SPIO) nanoparticles) and a magnetometer.…”

“…Injected tracer can be used for preoperative SPIO-enhanced magnetic resonance imaging (MRI) to visualize and identify the location of LNs with iron uptake [16,17]. Simultaneously, SPIOs are also used for intraoperative detection of SLNs by a magnetometer [10][11][12][13][14][15]. What should be considered is the difference in SPIO-sensitivity between MRI and the magnetometer [18].…”