Triple-site radiotracer application in breast lymphoscintigraphy and sentinel node discordance

Abstract

Sentinel lymph node (SLN) biopsy (SLNB) has demonstrated accuracy in the axillary staging of breast cancer patients. Despite variability in selection criteria and technique, an SLN is consistently identified in approximately 96% of cases and in most series predicts the status of remaining axillary LNs in >95% of cases. The false-negative rate of sentinel lymph node biopsy (SLNB) was originally reported as 5%–10% (sensitivity 90%–95%), but improved rates are attainable by experienced surgeons. Radiolocalization with lymphoscintigraphy (LSG) increases SLN identification rates. LSG is a useful tool to establish the abnormal lymphatic drainage patterns and to detect the extra-axillary nodes, particularly internal mammary nodes. Despite controversy regarding the optimal injection method, studies have generally suggested high concordance between the various radiotracer application sites and axillary SLN identification. Discordant SLN identification would have implications for nodal staging as the true SLN might not be identified with individual injection techniques. In the current study, imaging from consecutive patients presenting for breast LSG over a-19 month period was retrospectively reviewed. Radiotracer application was performed with simultaneous injection of peritumoral, subcutaneous, and subareolar regions. This application method provided a mechanism to assess the LSG drainage patterns with a view to assessing injection site concordance and SLN identification rates. Data from 123 breast LSG patients were reviewed. Using our radiotracer technique, the axillary SLN identification rate was 98%. A single axillary node was detected in 110, two axillary nodes were detected in 10, and no axillary node was detected in three patients. Among those 10 patients in whom two axillary nodes were seen, at least two cases of discordant drainage occurred from different injection sites. This study demonstrates that different LSG injection sites can result in the identification of different axillary sentinel nodes although this appears to be a rare event. This finding may be of clinical importance if the true SLN is sought. In addition, the multisite injection technique appears to be an optimal method of axillary SLN identification, with high SLN detection rates.

Risk factors for nonvisualization of the sentinel lymph node on lymphoscintigraphy in breast cancer patients

“…This study shows that reinjection is an adequate option to improve the SLN visualization rate for nuclear medicine departments which are flexible enough to apply an additional injection and imaging slots. Another interesting approach to reduce SLN nonvisualization may be a multisite injection technique [ 17 ]. Based on our findings, it may be of interest to evaluate in prospective studies the postulate that administration of both intratumoral and periareolar injections simultaneously to patients with non-palpable tumors and age ≥ 70 years or BMI ≥ 30 kg/m 2 may reduce preoperative SLN nonvisualization.…”

Update on Sentinel Lymph Node Methods and Pathology in Breast Cancer

“…Especially in cases where precise staging, including SLNs beyond the axilla, is necessary, alternative injection methods may be more appropriate [22]. Furthermore, the integration of two injection techniques in a single patient is increasingly being recommended in selected centers, as it has the potential to enhance SLN detection, reduce non-visualization rates, and offer comprehensive benefits [23].…”

Detection of Sentinel Lymph Nodes During Breast Cancer Surgery: A Literature Overview

“…Tiek paviršinis, tiek gilusis medžiagos suleidimo būdai turi savų privalumų. Dėl šios priežasties vis daugiau krūties vėžio gydymo centrų siūlo šių būdų kombinaciją [23]. Ji leidžia vizualizuoti ne tik pažasties, bet ir vidinius krūties sarginius limfmazgius.…”