Subdermal re-injection: a method to increase surgical detection of the sentinel node in breast cancer without increasing the false-negative rate

Internal mammary node involvement in patients with axilla-negative early breast cancer: a narrative review

Early breast cancer staging involves radiological and pathological evaluation of the tumour and regional lymph nodes. The internal mammary nodes (IMN) are an important site of possible metastasis and influence disease stage and prognosis. However, the recommendation for routine IMN assessment remains unclear. Internal mammary sentinel lymph node biopsy (SLNB) is associated with increased morbidity and an unknown survival benefit. Furthermore, the IMN are traditionally thought to be involved only synchronous with, or following, axillary node (AXN) metastasis. The aim of this review is to determine the prevalence of IMN metastasis in patients with axilla-negative early breast cancer. A narrative review of studies assessing IMN metastasis was performed. The literature search was completed using the database Medline (Ovid). Twenty-two retrospective studies were identified. The studies included data from SLNB, US, MRI, PET/CT and opportunistic biopsy during free-flap reconstruction (FFR). The prevalence of isolated IMN metastasis ranged from 1.2% to 17.9%.

The Sentinel Lymph Node in Breast Cancer: Problems Posed by Examination During Surgery. A Review of Current Literature and Management

The presence of tumor cells can be identified in the lymph node when metastasis has occurred from the primary cancer site into the lymph node (1) If the sentinel lymph node ganglion is negative for the presence of tumor cells at the time of histological examination, the other lymph nodes are also negative in 99% of cases. If no tumor cells are identified in the sentinel lymph node ganglion by histological examination, the other lymph nodes are also negative for the presence of tumor cells in 99% of cases. The sentinel lymph node advantageously replaces axillary dissection as a staging method in breast cancer T1 and T2 (2). Approximately 40% of breast cancers metastasize to axillary lymph nodes and metastatic extension depends on disease stage. Sentinel lymph nodes are affected in the following stages: T1a (4.3%), T1b (19.5%), T1c (23.8%), T2 (48.9%), T3 (66.7%).

[Selective biopsy of the sentinel lymph node in patients with breast cancer and previous excisional biopsy: is there a change in the reliability of the technique according to time from surgery?]

AIM

To assess the influence of time on the reliability of sentinel lymph node biopsy (SLNB) in breast cancer patients with previous excisional biopsy (EB), analyzing both the sentinel lymph node detection and the lymph node recurrence rate.

MATERIAL AND METHODS

Thirty-six patients with cT1/T2 N0 breast cancer and previous EB of the lesion underwent a lymphoscintigraphy after subdermal periareolar administration of radiocolloid, the day before SLNB. Patients were classified into two groups, one including 12 patients with up to 29 days elapsed between EB and SLNB (group A), and another with the remaining 24 in which time between both procedures was of 30 days or more (group B). Scintigraphic and surgical detection of the sentinel lymph node, histological status of the sentinel lymph node and of the axillary lymph node dissection, if performed, and lymphatic recurrences during follow-up, were analyzed.

RESULTS

Sentinel lymph node visualization at the lymphoscintigraphy and surgical detection were 100% in both groups. Histologically, three patients showed macrometastasis in the sentinel lymph node, one from group A and two from group B. None of the patients, not even those with malignancy of the sentinel lymph node, relapsed after a medium follow-up of 49.5 months (24-75).

CONCLUSION

Time elapsed between EB and SLNB does not influence the reliability of this latter technique as long as a superficial injection of the radiopharmaceutical is performed, proving a very high detection rate of the sentinel lymph node without evidence of lymphatic relapse during follow-up.

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

BACKGROUND

In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate.

METHODS

We found 3,588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9,306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published.

RESULTS

There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant.

CONCLUSIONS

The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.

A novel finding of sentinel lymphatic channels in early stage breast cancer patients: which may influence detection rate and false-negative rate of sentinel lymph node biopsy

Background

The exact lymphatic drainage pattern of the breast hasn't been explained clearly. The aim of this study was to investigate the sentinel lymphatic channels (SLCs) in the cancerous breast. Whether the type of SLCs influenced the detection rate and false-negative rate of SLNB was also assessed.

Methodology and Principal Findings

Mimic SLNB was performed in 110 early-stage breast cancer patients with subareolar injection of blue methylene dye intraoperatively. Postoperatively, 110 specimens of modified radical mastectomy were examined for all blue SLCs after additional injection of methylene dye in peritumoral parenchyma. Interestingly, three types of SLCs, including superficial sentinel lymphatic channel (SSLC), deep sentinel lymphatic channel (DSLC), and penetrating sentinel lymphatic channel (PSLC) were found in 107 patients. Six lymphatic drainage patterns based on the three types of SLCs were observed in these 107 patients. The proportions of the drainage pattern SSLC, DSLC, PSLC, SSLC+DSLC, SSLC+PSLC, and DSLC+PSLC in the breast were 43%, 0.9%, 15.9%, 33.6%, 3.7% and 2.8%, respectively. The lymphatic drainage pattern in the breast was a significant risk factor for unsuccessful identification of sentinel lymph nodes (P<0.001) and false-negatives in SLNB (P = 0.034) with the subareolar injection technique.

Conclusions

Three kinds of SLCs are the basis of six lymphatic drainage patterns from the breast to the axilla. The type of SLCs is the factor influencing the detection rate and false-negative rate of SLNB. These findings suggest the optimal injection technique of the combination of superficial and deep injection in SLNB procedures. Future clinical studies are needed to confirm our novel findings.

Nonvisualization of sentinel node by lymphoscintigraphy in advanced breast cancer

Previous studies have shown that an increased number of axillary lymph nodes with metastatic involvement is associated with nonvisualization of lymph nodes during lymphoscintigraphy. We report a case of nonvisualization of the sentinel node during lymphoscintigraphy in a female with advanced breast cancer to support this association. Although many factors can affect visualization of the sentinel node during lymphoscintigraphy, the presence of advanced metastatic disease involving the lymphatic system must always be considered.

Lymphatic mapping with 99mTc-Evans Blue dye in sheep

OBJECTIVE

99mTc-Evans Blue (EB) is an agent that contains both radioactive and color signals in a single dose. Earlier studies in animal models have suggested that this agent when compared with the dual-injection technique of radiocolloid/blue dye can successfully discriminate the sentinel lymph node. The aim of this study was to investigate the potential of 99mTc-EB as an agent to map the lymphatic system in an ovine model.

METHODS

Doses of 99mTc-EB (23 MBq) containing EB dye (4 mg) were administered intradermally to the limbs of four anesthetized sheep, and they were then imaged over 20-30 min using a gamma camera. The study protocol was repeated using 99mTc-antimony trisulfide colloid (ATC) and Patent Blue V dye. The lymph nodes (popliteal, inguinal, and iliac for hind limbs or prescapular for fore limbs) were identified with a gamma probe during the operative exposure, then dissected and counted in a large volume counter.

RESULTS

Simple and complex (dual) drainage patterns were visible on the scans, and the sentinel node was more radioactive than higher tier nodes in a chain, for both radiotracers. For 99mTc-EB, maximum radioactive uptake was achieved at 3-6 min for popliteal lymph nodes, 12-14 min for iliac nodes, and 13-14 min for prescapular nodes. 99mTc-ATC resulted in maximum radioactive uptake at 4-6 min for popliteal lymph nodes, 13 min for an inguinal node, 13-20 min for iliac nodes, and 18 min for a prescapular node. Following 99mTc-EB injection, 15/15 lymph nodes harvested were all radioactive and blue. For 99mTc-radiocolloid/Patent Blue V injection, 8/14 nodes were radioactive and blue, and 6/14 nodes were radioactive only.

CONCLUSIONS

The soluble radiotracer 99mTc-EB appeared to be a useful lymphoscintigraphic agent in sheep, in which radioactive counts from superficial lymphatic channels and lymph nodes were sufficient for planar imaging. In comparison with 99mTc-antimony trisulfide colloid, both tracers discriminated the sentinel lymph node up to 50 min after administration; however, 99mTc-EB had the advantage of providing radioactive (gamma probe) and color signals simultaneously during the operative exposure.