Evolution and refinement of magnetically guided sentinel lymph node detection in breast cancer: meta-analysis

Abstract

Background Superparamagnetic iron oxide nanoparticles (SPIO) have been used as a tracer for sentinel lymph node (SLN) localization in breast cancer, demonstrating comparable performance to the combination of radioisotope (RI) and blue dye (BD). Methods A systematic literature search and meta-analysis with subgroup and meta-regression analysis were undertaken to update the available evidence, assess technique evolution, and define knowledge gaps. Recommendations were made using the GRADE approach. Results In 20 comparative studies, the detection rate was 97.5 per cent for SPIO and 96.5 per cent for RI ± BD (risk ratio 1.006, 95 per cent c.i. 0.992 to 1.019; P = 0.376, high-certainty evidence). Neoadjuvant therapy, injection site, injection volume or nodal metastasis burden did not affect the detection rate, but injection over 24 h before surgery increased the detection rate on meta-regression. Concordance was 99.0 per cent and reverse concordance 97.1 per cent (rate difference 0.003, 95 per cent c.i. −0.009 to 0.015; P = 0.656, high-certainty evidence). Use of SPIO led to retrieval of slightly more SLNs (pooled mean 1.96 versus 1.89) with a higher nodal detection rate (94.1 versus 83.5 per cent; RR 1.098, 1.058 to 1.140; P < 0.001; low-certainty evidence). In meta-regression, injection over 24 h before surgery increased the SPIO nodal yield over that of RI ± BD. The skin-staining rate was 30.8 per cent (very low-certainty evidence), and possibly prevented with use of smaller doses and peritumoral injection. Conclusion The performance of SPIO is comparable to that of RI ± BD. Preoperative injection increases the detection rate and nodal yield, without affecting concordance. Whether skin staining and MRI artefacts are reduced by lower dose and peritumoral injection needs to be investigated.

Magnetic Seed vs Guidewire Breast Cancer Localization With Magnetic Lymph Node Detection

“…Previous studies have investigated solely magnetic lesion localization and others solely magnetic SLN detection; the outcomes were comparable with the guidewire and, respectively, RI with or without BD . Paramagnetic markers and SPIO both have the benefit of decoupling the respective procedure from the day of surgery; however, if not combined, this benefit is not being fully utilized.…”

“…In the experimental arm, lesion localization was performed with the Magseed marker (Endomag), a 5-mm paramagnetic seed used for the localization of breast cancer lesions, and in the control arm, with a guidewire (Bard Peripheral Vascular Inc). Regardless of randomization, because SPIO dose and injection timing do not affect SLN detection, patients received 1 to 1.5 mL of Magtrace (Endomag), a nonradioactive liquid tracer containing iron oxide nanoparticles, dorsally to the tumor, at any point between the preoperative visit for surgical planning to the day of surgery, either simultaneously with lesion localization or not . Following trial pragmatism, the placement of the marker and the administration of SPIO were to be performed according to local routines or case-by-case convenience, meaning that surgeons or radiologists could insert the paramagnetic marker with or without simultaneous injection of the liquid tracer preoperatively, whereas guidewires were exclusively inserted by a breast radiologist on the day of the surgery or the day before.…”

“…Although highly reliable, this combination poses challenges due to restricted access to nuclear medicine facilities, strict regulations, and risk of allergic reaction to BD, whereas the short half-life of the RI limits administration on the day of surgery or the day before, complicating logistics. Superparamagnetic iron oxide (SPIO) nanoparticles have shown comparable performance with an RI with or without BD with the additional advantage of a wider time frame of preoperative administration . Perceived drawbacks of the method are skin staining and artifacts on postoperative magnetic resonance imaging (MRI); a recent meta-analysis, however, suggests that peritumoral SPIO administration could address these concerns, without any compromise of SLN detection outcomes.…”

“…Superparamagnetic iron oxide (SPIO) nanoparticles have shown comparable performance with an RI with or without BD with the additional advantage of a wider time frame of preoperative administration . Perceived drawbacks of the method are skin staining and artifacts on postoperative magnetic resonance imaging (MRI); a recent meta-analysis, however, suggests that peritumoral SPIO administration could address these concerns, without any compromise of SLN detection outcomes.…”

Magnetically guided surgery after primary systemic therapy for breast cancer: implications for enhanced axillary mapping

“…Superparamagnetic iron nanoparticles (SPIO) have shown comparable performance to radioisotope ± blue dye for sentinel lymph node (SLN) detection (SLND) in breast cancer, with the convenience of easier accessibility, disposal, and administration days before surgery 1 . Moreover, SPIO provide the possibility for delayed SLND, as demonstrated in the SentiNot study.…”