Axillary concordance between superficial and deep sentinel node mapping material injections in breast cancer patients: systematic review and meta-analysis of the literature

Discordance between peritumoral and subareolar injections for mapping sentinel lymph nodes in the breast

PURPOSE

Sentinel node biopsy (SNB) is a common staging tool for breast cancer. Initially, peritumoral (PT) injections were used, however subareolar (SA) injections were later introduced to simplify the technique. Controversy remains regarding whether PT and SA injections map the same sentinel lymph nodes (SLNs). This study aimed to determine whether the regional location of breast SLNs differs when using PT versus SA injections using a large dataset from a single institution.

METHODS

A total of 1035 patients who underwent breast SNB (PT injections: n = 858 and SA injections: n = 177) with lymphoscintigraphy and SPECT/CT were included. The identified SLN locations using SA injections were compared with those using PT injections. Differences in drainage proportions and odds ratios (ORs) for each clockface breast region and the whole breast were calculated using a two-proportion z-test and Fisher's Exact Test.

RESULTS

A higher proportion of internal mammary SLNs were identified using PT injections for the whole breast (0.30 versus 0.09) and for all breast regions, with all regions showing statistical significance except the upper outer quadrant. Similarly, ORs showed identification of internal mammary SLNs was significantly higher when using PT injections (4.35, 95% CI 2.53 to 7.95). There were no significant differences in identifying axillary SLNs between injection sites.

CONCLUSION

This is the largest cohort study to compare the regional location of breast SLNs identified using PT injections versus SA injections. Discordance was shown in the SLNs identified between injection techniques, with PT injections more frequently identifying internal mammary SLNs.

Sentinel lymph node localization and staging with a low-dose of superparamagnetic iron oxide (SPIO) enhanced MRI and magnetometer in patients with cutaneous melanoma of the extremity - The MAGMEN feasibility study

BACKGROUND

In patients with melanoma, sentinel lymph node (SLN) status is pivotal for treatment decisions. Current routine for SLN detection combines Technetium^99m (Tc⁹⁹) lymphoscintigraphy and blue dye (BD). The primary aim of this study was to examine the feasibility of using a low dose of superparamagnetic iron oxide (SPIO) injected intracutaneously to detect and identify the SLN, and the secondary aim was to investigate if a low dose of SPIO would enable a preoperative MRI-evaluation of SLN status.

METHODS

Patients with melanoma of the extremities were eligible. Before surgery, a baseline MRI of the nodal basin was followed by an injection of a low dose (0.02-0.5 mL) of SPIO and then a second MRI (SPIO-MRI). Tc⁹⁹ and BD was used in parallel and all nodes with a superparamagnetic and/or radioactive signal were harvested and analyzed.

RESULTS

Fifteen patients were included and the SLNB procedure was successful in all patients (27 SLNs removed). All superparamagnetic SLNs were visualized by MRI corresponding to the same nodes on scintigraphy. Micrometastatic deposits were identified in four SLNs taken from three patients, and SPIO-MRI correctly predicted two of the metastases. There was an association between MRI artefacts in the lymph node and the dose SPIO given.

DISCUSSION

It is feasible to detect SLN in patients with melanoma using a low dose of SPIO injected intracutaneously compared with the standard dual technique. A low dose of SPIO reduces the lymph node MRI artefacts, opening up for a non-invasive assessment of SLN status in patients with cancer.

The impact of drainage pathways on the detection of nodal metastases in prostate cancer: a phase II randomized comparison of intratumoral vs intraprostatic tracer injection for sentinel node detection

INTRODUCTION

Previous studies indicated that location and amount of detected sentinel lymph nodes (SLNs) in prostate cancer (PCa) are influenced where SLN-tracer is deposited within the prostate. To validate whether intratumoral (IT) tracer injection helps to increase identification of tumor-positive lymph nodes (LNs) better than intraprostatic (IP) tracer injection, a prospective randomized phase II trial was performed.

METHODS

PCa patients with a > 5% risk of lymphatic involvement were randomized between ultrasound-guided transrectal injection of indocyanine green-[^99mTc]Tc-nanocolloid in 2 depots of 1 mL in the tumor (n = 55, IT-group) or in 4 depots of 0.5 mL in the peripheral zone of the prostate (n = 58, IP-group). Preoperative lymphoscintigraphy and SPECT/CT were used to define the location of the SLNs. SLNs were dissected using combination of radio- and fluorescence-guidance, followed by extended pelvic LN dissection and robot-assisted radical prostatectomy. Outcome measurements were number of tumor-bearing SNs, tumor-bearing LNs, removed nodes, number of patients with nodal metastases, and metastasis-free survival (MFS) of 4-7-year follow-up data.

RESULTS

IT-injection did not result in significant difference of removed SLNs (5.0 vs 6.0, p = 0.317) and histologically positive SLNs (28 vs 22, p = 0.571). However, in IT-group, the SLN-positive nodes were 73.7% of total positive nodes compared to 37.3% in IP-group (p = 0.015). Moreover, significantly more node-positive patients were found in IT-group (42% vs 24%, p = 0.045), which did not result in worse MFS. In two patients (3.6%) from whom the IT-tracer injection only partly covered intraprostatic tumor spread, nodal metastases in ePLND without tumor-positive SNs were yielded.

CONCLUSIONS

The percentage-positive SLNs found after IT-injection were significantly higher compared to IP-injection. Significantly more node-positive patients were found using IT-injection, which did not affect MFS. IT-injection failed to detect nodal metastases from non-index satellite lesions. Therefore, we suggest to combine IT- and IP-tracer injections in men with visible tumor on imaging.

Repeat injection following sentinel node nonvisualization on lymphoscintigraphy images can decrease axillary dissection rate in breast cancer patients

AIM

Sentinel node biopsy is considered the standard of care in early-stage breast cancer patients. In the current study, we evaluated the effect of radiotracer reinjection in the case of sentinel node nonvisualization on preoperative lymphoscintigraphy.

MATERIALS AND METHODS

Between March 2017 and March 2020, 1850 early-stage breast cancer patients were referred for sentinel node mapping. All patients received a single injected activity of Tc-99m Phytate intradermally in the periareolar area of the index lesion using an insulin syringe. Lymphoscintigraphy images of the patients were done 1-2 h postinjection. Between March 2017 and September 2017, sentinel node nonvisualization was reported to the surgeon, and for the rest of the study period, the patients received another injected activity of the radiotracer, and immediately, other lymphoscintigraphy images were taken (with the same parameters).

RESULTS

A total of 255 patients entered our study. Fifty-five patients were in group I without any reinjection. The remainder of the patients were in group II. In 155 out of 200 patients of group II, a sentinel node could be visualized following reinjection of the radiotracer. The detection rate was 15 out of 45 and 15 out of 55 in group I and patients without sentinel node visualization even after reinjection, respectively. Axilla was involved in 5 out of 40 (12.5%) patients in group I with intraoperative sentinel node mapping failure. On the other hand, axilla was involved in 27 out of 30 (90%) group II patients with sentinel node nonvisualization.

CONCLUSION

Reinjection of the tracer in cases of no sentinel node visualization in lymphoscintigraphy for breast cancer increases the detection rate of sentinel nodes, and therefore a high number of unnecessary axillary lymph node dissections can be avoided.

Concordance Between Intracervical and Fundal Injections for Sentinel Node Mapping in Patients With Endometrial Cancer?

Objective

A major controversy in sentinel node (SN) biopsy of endometrial cancer is the injection site of mapping material. We compared lymphatic drainage pathways of the uterine cervix and uterine body in the same patients by head-to-head comparison of intracervical radiotracer and fundal blue dye injections.

Methods

All patients with pathologically proven endometrial cancer were included. Each patient received 2 intracervical injections of 99mTc-phytate. At the time of laparotomy, the uterus was exposed, and each patient was injected with 2 aliquots of patent blue V (2 mL each) in the subserosal fundal midline locations. The anatomical locations of all hot, blue, or hot/blue SNs were recorded.

Results

Overall, 45 patients entered the study. At least 1 SN could be identified in 75 of 90 hemipelves (83.3% overall detection rate, 82.2% for radiotracer [intracervical] alone, and 81.1% for blue dye [fundal] alone). In 71 hemipelves, SNs were identified with both blue dye (fundal) and radiotracer (intracervical) injections. In 69 of these 71 hemipelves, at least 1 blue/hot SN could be identified (97.18% concordance rate). In 10 patients, para-aortic SNs were identified. All of these nodes were identified by fundal blue dye injection, and only 2 were hot.

Conclusions

Our study shows that lymphatic drainage to the pelvic area from the uterine corpus matches the lymphatic pathways from the cervix, and both intracervical and fundal injections of SN mapping materials go to the same pelvic SNs.

Sentinel lymph node biopsy in breast cancer: a technical and clinical appraisal

Breast cancer is the most common type of cancer diagnosed in women worldwide. Regional lymph node status is one of the strongest predictors of long-term prognosis in primary breast cancer. Sentinel lymph node biopsy (SLNB) has replaced axillary lymph node dissection as the standard surgical procedure for staging clinically tumor-free regional nodes in patients with early-stage breast cancer. SLNB staging considerably reduces surgical morbidity in terms of shoulder dysfunction and lymphedema, without affecting diagnostic accuracy and prognostic information. Clinicians should not recommend axillary lymph node dissection for women with early-stage breast cancer who have tumor-free findings on SLNB because there is no advantage in terms of overall survival and disease-free survival. Starting from the early 1990s, SLNB has increasingly been used in breast cancer management, but its role is still debated under many clinical circumstances. Moreover, there is still a lack of standardization of the basic technical details of the procedure that is likely to be responsible for the variability found in the false-negative rate of the procedure (5.5-16.7%). In this article, we report the aspects of SLNB that are well established, those that are still debated, and the advancements that have taken place over the last 20 years. We have provided an update on the methodology from both a technical and a clinical point of view in the light of the most recent publications.

Sentinel Lymph Node Biopsy in Breast Cancer: Indications, Contraindications, and Controversies

Axillary lymph node status, a major prognostic factor in early-stage breast cancer, provides information important for individualized surgical treatment. Because imaging techniques have limited sensitivity to detect metastasis in axillary lymph nodes, the axilla must be explored surgically. The histology of all resected nodes at the time of axillary lymph node dissection (ALND) has traditionally been regarded as the most accurate method for assessing metastatic spread of disease to the locoregional lymph nodes. However, ALND may result in lymphedema, nerve injury, shoulder dysfunction, and other short-term and long-term complications limiting functionality and reducing quality of life. Sentinel lymph node biopsy (SLNB) is a less invasive method of assessing nodal involvement. The concept of SLNB is based on the notion that tumors drain in an orderly manner through the lymphatic system. Therefore, the SLN is the first to be affected by metastasis if the tumor has spread, and a tumor-free SLN makes it highly unlikely for other nodes to be affected. Sentinel lymph node biopsy has become the standard of care for primary treatment of early breast cancer and has replaced ALND to stage clinically node-negative patients, thus reducing ALND-associated morbidity. More than 20 years after its introduction, there are still aspects concerning SLNB and ALND that are currently debated. Moreover, SLNB remains an unstandardized procedure surrounded by many unresolved controversies concerning the technique itself. In this article, we review the main indications, contraindications, and controversies of SLNB in breast cancer in the light of the most recent publications.

Sentinel lymph node identification using superparamagnetic iron oxide particles versus radioisotope: The French Sentimag feasibility trial

BACKGROUND AND OBJECTIVES

The French Sentimag feasibility trial evaluated a new method for the localization of breast cancer sentinel lymph node (SLN) using Sienna+®, superparamagnetic iron oxide particles, and Sentimag® detection in comparison to the standard technique (isotopes ± blue dye).

METHODS

We conducted a prospective multicentric paired comparison trial on 115 patients. SLN localization was performed using both the magnetic technique and the standard method. Detection rate and concordance between magnetic and standard tracers were calculated. Post-operative complications were assessed after 30 days.

RESULTS

Results are based on 108 patients. SLN identification rate was 98.1% [93.5-99.8] for both methods, 97.2% [92.1-99.4] for Sienna+® and 95.4% [89.5-98.5] for standard technique. A mean of 2.1 SLNs per patient was removed. The concordance rate was 99.0% [94.7-100.0%] per patient and 97.4% [94.1-99.2] per node. Forty-six patients (43.4%) had nodal involvement. Among involved SLNs, concordance rate was 97.7% [88.0-99.9] per patient and 98.1% [90.1-100.0] per node.

CONCLUSIONS

This new magnetic tracer is a feasible method and a promising alternative to the isotope. It could offer benefits for ambulatory surgery or sites without nuclear medicine departments. J. Surg. Oncol. 2016;113:501-507. © 2016 Wiley Periodicals, Inc.

Sentinel lymph node identification rates and axillary concordance can only be accurately determined by comparing 'like with like' injected materials

PURPOSE

Despite the accepted status of sentinel lymph node biopsy (SLNB) as the standard for axillary staging in breast cancer patients with clinically and radiologically negative axillae pre-operatively, there is surprisingly still a lack of consensus on the most appropriate site of injection of radioactive tracer with or without blue dye.

METHODS

We discuss the article by Sadeghi et al. "Axillary concordance between superficial and deep sentinel node mapping material injections in breast cancer patients: systematic review and meta-analysis of the literature." Breast Cancer Res Treat 144(2): 213-222.

RESULTS

Whilst in this study both comparison arms (superficial and deep injections) were in the same patients to ensure comparability of evaluated groups, this does limit the conclusions, which can be drawn from this study. It has meant that when comparing intra-operative sentinel lymph node (SLN) identification and concordance rates, it is not possible to compare 'like with like' at different injection sites (deep radioactive tracer vs superficial radioactive tracer; superficial blue dye vs deep blue dye). This leads to inaccurate conclusions due to the different properties of these materials.

CONCLUSIONS

The only way to determine the optimal injection site of radioactive tracer and blue dye for SLN identification intra-operatively and accurate concordance rates is by direct comparisons of 'like with like' when it comes to injected materials at different injection sites.