Identification of Sentinel Lymph Nodes Using Contrast-Enhanced Ultrasound in Breast Cancer

Can preoperative percutaneous injection of ultrasound contrast agent locate sentinel lymph nodes of breast cancer?

Objectives

We evaluated the ability and accuracy of preoperative identification and localization of sentinel lymph nodes (SLNs) using intradermal injection of ultrasound contrast agent.

Materials and methods

Prospectively recruited 191 early breast cancer patients with clinically negative axillary lymph nodes (ALNs). All participants received intradermal injection of microbubble contrast agent. Following the identification and localization of SLNs using contrast-enhanced ultrasound (CEUS), Markers were deployed in the SLNs US-guided. Subsequently, the SLNs with Markers were stained and marked with a suspension of nano-carbon US-guided to assist in intraoperative localization of SLNs. Standard SLNB with methylene blue tracing was performed intraoperatively to assess the consistency between the two methods of SLNs localization, thereby determining the ability and accuracy of CEUS in identifying and localizing SLNs.

Results

A total of 179 patients were included in the final evaluation analysis, in which a microbubble contrast agent was injected subcutaneously in the areolar region. A total of 201 SLNs were identified, with a median of 1 SLN per patient. Each SLN was identified in 157 patients, and two SLNs were identified in 22 patients. Among the 201 SLNs from the 179 patients, the proportion that could be individually matched between CEUS and the blue dye method was 95.5% (192/201), and the consistency evaluation in SLNs identification between CEUS and blue dye staining was excellent (Kappa value = 0.62, P < 0.001).

Conclusion

The consistency of identification and localization of SLNs in early breast cancer patients between CEUS and the blue dye method was strong.

Advantages of contrast-enhanced ultrasound in the localization and diagnostics of sentinel lymph nodes in breast cancer

Sentinel lymph nodes (SLNs) are the first station of lymph nodes that extend from the breast tumor to the axillary lymphatic drainage. The pathological status of these LNs can predict that of the entire axillary lymph node. Therefore, the accurate identification of SLNs is necessary for sentinel lymph node biopsy (SLNB) to replace axillary lymph node dissection (ALND). The quality of life and prognosis of breast cancer patients are related to proper surgical treatment after the precise identification of SLNs. Some of the SLN tracers that have been identified include radioisotope, nano-carbon, indocyanine green (ICG), and methylene blue (MB). However, these tracers have certain limitations, such as pigmentation, radiation dangers, and the requirement for costly detection equipment. Ultrasound contrast agents (UCAs) have good specificity and sensitivity, and thus can compensate for some shortcomings of the mentioned tracers. This technique is also being applied to SLNB in patients with breast cancer, and can even provide an initial judgment on SLN status. Contrast-enhanced ultrasound (CEUS) has the advantages of high distinguishability, simple operation, no radiation harm, low cost, and accurate localization; therefore, it is expected to replace the traditional biopsy methods. In addition, it can significantly enhance the accuracy of SLN localization and shorten the operation time.

Safety and Efficacy of Mitoxantrone Hydrochloride Injection for Identification of Axillary Sentinel Lymph Nodes in Patients with Primary Breast Cancer

BACKGROUND

The dual technique using blue dye in combination with a radioisotope is considered the gold standard for identifying sentinel lymph nodes (SLNs) in patients with breast cancer. Unfortunately, not all cancer centres have access to radioactive material, which jeopardizes the SLN identification rate and patient safety.

AIM

We aimed to assess the safety and efficacy of mitoxantrone hydrochloride injection (MHI) for identifying axillary SLNs in patients with primary breast cancer.

PATIENTS AND METHODS

We have conducted a prospective non-randomized analysis of patients diagnosed with invasive breast cancer who agreed to participate in the study between December 2019 and December 2022. We have used the patient's medical records to collect the data. We have used the SLN intraoperative identification rate as a marker for the efficacy of the technique and both the immediate and delayed complication rates and routine blood tests as markers for the safety of the technique.

RESULTS

Out of the 296 patients, 289 (97.6%) had their SLNs identified using MHI, while seven patients (2.3%) had four-node sampling carried out because the SLNs were not identified. Liver functions were not significantly affected by MHI, and there was no technique-related readmission or reported morbidity or mortality.

CONCLUSION

We have found that the MHI technique is still inferior to the combined radioactive directed technique and patent blue V dye in SLN identification. Yet, it may serve as a safe and reliable alternative in cases where the radioactive technique is unavailable.

Study on Sentinel Lymph Node and Its Lymphatic Drainage Pattern of Breast Cancer by Contrast-Enhanced Ultrasound

OBJECTIVES

Sentinel lymph node (SLN) and its lymphatic drainage pattern (LDP) of breast cancer were studied by contrast-enhanced ultrasound (CEUS).

METHODS

From July 2017 to December 2019, patients with SLN localization of breast cancer in Sichuan Academy of Medical Sciences·Sichuan Provincial People's Hospital were selected. The sentinel lymph system of breast cancer was observed by CEUS before both operation and blue staining in the surgery. The location, number, and route of sentinel lymphatic channel (SLC) were recorded, along with the number, size, and the depth from skin of SLN. LDPs were summarized according to these basic characteristics of SLC and SLN.

RESULTS

A total of 368 cases were included; 465 SLCs and 423 SLNs were detected. Most of the SLCs were originated from the outer upper quadrant of areola. Eleven LDPs were found, including 31 subtypes of LDPs. There were 6 cases of type A (1.63%), 15 cases of type B (4.08%), 223 cases of type C (57.88%), 38 cases of type D (10.33%), 2 cases of type E (0.54%), 3 cases of type F (0.82%), 50 cases of type G (13.59%), 30 cases of type H (8.15%), 2 cases of type I (0.54%), 6 cases of type J (1.63%), and 3 cases of type K (0.82%).

CONCLUSIONS

The most common LDP of breast cancer was one SLC originated from the upper quadrant of areola with one SLN. CEUS can identify the LDP before surgery to reduce the false negative rate of SLN biopsy.

Meta-Analysis of the Diagnostic Value of Tracer Staining Technology Based on Nanocarbon Suspension in Sentinel Lymph Node Biopsy of Breast Cancer

Objective. To evaluate the diagnostic value of the nanometer carbon suspension tracer staining technique in sentinel lymph node biopsy of breast cancer is the objective of this study. Methods. The PubMed, Embase, Cochrane Library (Central), and Web of Science (SCI Expanded), and Chinese databases (CNKI, VIP, Wan Fang, and CBM) were systematically searched for studies on the diagnostic value of nanocarbon suspension in sentinel lymph node biopsy of breast cancer. Two reviewers independently assessed the methodological quality of each study using the QUADAS-2 tool. The extracted valid data were calculated using Meta-Disc1.4 software and tested for heterogeneity. STATA14.0 software was selected for sensitivity analysis of the included studies, and publication bias was assessed using Deeks’ forest plot asymmetry test. Results. A total of 10 studies were obtained. The pooled data were as follows: sensitivity, 0.92 (0.88~0.95); specificity, 0.99 (0.98~1.00); positive likelihood ratio, 69.24 (30.34~158.02); negative likelihood ratio, 0.09 (0.06~0.13); and the combined diagnostic odds ratio, 747.40 (285.77~1954.76), $\text{AUC}=0.9881$ . Nanocarbon suspension tracers have an accuracy rate of 98.81% in the diagnosis of sentinel lymph nodes in breast cancer. Conclusion. Tracer staining technology based on nanocarbon suspension can accurately assess the status of lymph nodes in sentinel lymph node biopsy of breast cancer and has good stability and operability, which is worthy of clinical promotion.

Diagnostic efficacy of sentinel lymph node in breast cancer under percutaneous contrast-enhanced ultrasound: An updated meta-analysis

Background

To investigate the diagnostic efficacy of sentinel lymph nodes (SLN) in breast cancer by percutaneous contrast‐enhanced ultrasound (CEUS) through pooled analysis of relevant studies published before June 2021.

Methods

We conducted a systematic review and meta‐analysis of relevant studies by searching the electronic databases of PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang and VIP and the studies were screened according to their inclusion and exclusion criteria. Sensitivity (SEN), specificity (SPE), positive likelihood ratio (+LR), negative likelihood ratio (−LR) and diagnostic odds ratio (DOR) were calculated by Meta‐disc 1.4 software and the summary receiver operating characteristic (SROC) curve and area under the curve of ROC (AUC) were constructed.

Results

Twenty‐two publications evaluating the diagnostic efficacy of SLN in breast cancer under percutaneous CEUS were included in the meta‐analysis. The diagnostic sensitivity, specificity were 0.86 (95% CI: 0.83–0.88) and 0.89 (95% CI: 0.87–0.91) for SLN in breast cancer detected by percutaneous CEUS respectively using a random effect model. The +LR and –LR were combined in a random effect model due to significant statistical heterogeneity (p < 0.05). The pooled +LR, −LR were 7.06 (95% CI: 4.34–11.50), and 0.17 (95% CI: 0.12–0.24), respectively. The combined DOR was 53.32 (95% CI: 29.74–95.61) for SLN diagnosis in breast cancer by percutaneous CEUS under a random effect model. The AUC was 0.94 which indicated that CEUS had high diagnostic efficacy of SLN in patients with breast cancer.

Conclusions

CEUS is a noninvasive method for the detection SLN in patients of breast cancer with relative high prediction efficacy.

Pharmacokinetic parameters and radiomics model based on dynamic contrast enhanced MRI for the preoperative prediction of sentinel lymph node metastasis in breast cancer

Background

To establish pharmacokinetic parameters and a radiomics model based on dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for predicting sentinel lymph node (SLN) metastasis in patients with breast cancer.

Methods

A total of 164 breast cancer patients confirmed by pathology were prospectively enrolled from December 2017 to May 2018, and underwent DCE-MRI before surgery. Pharmacokinetic parameters and radiomics features were derived from DCE-MRI data. Least absolute shrinkage and selection operator (LASSO) regression method was used to select features, which were then utilized to construct three classification models, namely, the pharmacokinetic parameters model, the radiomics model, and the combined model. These models were built through the logistic regression method by using 10-fold cross validation strategy and were evaluated on the basis of the receiver operating characteristics (ROC) curve. An independent validation dataset was used to confirm the discriminatory power of the models.

Results

Seven radiomics features were selected by LASSO logistic regression. The radiomics model, the pharmacokinetic parameters model, and the combined model yielded area under the curve (AUC) values of 0.81 (95% confidence interval [CI]: 0.72 to 0.89), 0.77 (95% CI: 0.68 to 0.86), and 0.80 (95% CI: 0.72 to 0.89), respectively, for the training cohort and 0.74 (95% CI: 0.59 to 0.89), 0.74 (95% CI: 0.59 to 0.90), and 0.76 (95% CI: 0.61 to 0.91), respectively, for the validation cohort. The combined model showed the best performance for the preoperative evaluation of SLN metastasis in breast cancer.

Conclusions

The model incorporating radiomics features and pharmacokinetic parameters can be conveniently used for the individualized preoperative prediction of SLN metastasis in patients with breast cancer.

Quantitative assessment of microcirculation perfusion state of rectal cancer patients after neoadjuvant treatment by contrast-enhanced ultrasound

BACKGROUND

Neoadjuvant treatment is helpful to improve the postoperative curative effect, reduce the recurrence rate, and improve the life quality of patients with rectal cancer. It is of great significance to evaluate the curative effect accurately. As a new ultrasound technology, contrast-enhanced ultrasound (CEUS) can display the microcirculation state of target tissue in real time, thus providing reliable hemodynamic information for clinical evaluation.

AIM

To evaluate the changes of microcirculation perfusion state of rectal cancer patients after neoadjuvant treatment by CEUS, and its correlation with microvessel density (MVD).

METHODS

One hundred and six patients with advanced rectal cancer who underwent neoadjuvant treatment were selected at our hospital. All patients underwent CEUS before and after treatment. The parameters of microcirculation perfusion were measured by CEUS, and compared with MVD of the samples after the operation.

RESULTS

The maximum diameter of the lesion after treatment was significantly reduced than that before treatment (P < 0.05). The area under the curve (AUC) and the peak intensity (PI) of the lesion after treatment were significantly decreased than those before treatment (P < 0.05). The PI and AUC after treatment were positively correlated with MVD (r = 0.82, P < 0.05; r = 0.79, P < 0.05), respectively.

CONCLUSION

CEUS can objectively reflect the microcirculation perfusion state of rectal cancer patients, and its perfusion parameters have a good correlation with MVD, which can provide hemodynamic information for clinical evaluation of neoadjuvant treatment of rectal cancer.

Role of gamma probe-assisted intraoperative sentinel lymph node evaluation in predicting axillary breast cancer metastasis after neoadjuvant chemotherapy

OBJECTIVE

Intraoperative sentinel lymph node biopsy is a universally accepted technique to identify patients who are candidates for axillary lymph node dissection during breast cancer surgery. However, there is controversy over its use in patients who underwent preoperative neoadjuvant chemotherapy. This study aimed to examine the diagnostic value of gamma probe-assisted intraoperative sentinel lymph node examination with frozen section in breast cancer patients who had undergone preoperative neoadjuvant chemotherapy.

METHODS

This retrospective study included 94 tumors diagnosed with stage IIA, IIB or IIIA invasive breast cancer with locoregional lymph node metastasis who underwent surgical treatment after neoadjuvant chemotherapy. Intraoperatively, axillary sentinel lymph node sampling was done using radioactive colloid and gamma probe and materials were examined with frozen section method. Patients with positive sentinel nodes underwent axillary resection. Histopathological examination of all surgical samples was done postoperatively.

RESULTS

In 87 of 94 tumors (92.6%), a sentinel lymph node could be identified using the method. The sensitivity, specificity and accuracy of the method for predicting axillary macro metastasis were 85.7, 86.5 and 86.2%, respectively, with 5.7% false negative rate.

CONCLUSIONS

Sentinel lymph node identification using preoperative scintigraphy and intraoperative use of gamma probe seems to be a feasible and efficient method in terms of differentiating patients that require axillary lymph node dissection during breast cancer surgery, even when they have received neoadjuvant chemotherapy. Further large prospective studies allowing subgroup analyses are warranted.

Ultrasound-guided immunofunctional photoacoustic imaging for diagnosis of lymph node metastases

Metastases, rather than primary tumors, determine mortality in the majority of cancer patients. A non-invasive immunofunctional imaging method was developed to detect sentinel lymph node (SLN) metastases using ultrasound-guided photoacoustic (USPA) imaging combined with glycol-chitosan-coated gold nanoparticles (GC-AuNPs) as an imaging contrast agent. GC-AuNPs, injected peritumorally into breast tumor-bearing mice, were taken up by immune cells, and subsequently transported to the SLN. Two-dimensional and three-dimensional USPA imaging was used to isolate the signal from GC-AuNP-tagged cells. Volumetric analysis was used to quantify GC-AuNP accumulation in the SLN after cellular uptake and transport by immune cells. The results show that the spatio-temporal distribution of GC-AuNPs in the SLN was affected by the presence of metastases. The parameter describing the spatial distribution of GC-AuNP-tagged cells within the SLN was more than 2-fold lower in metastatic lymph nodes compared with non-metastatic controls. Histological analysis confirmed that the distribution of GC-AuNP-tagged immune cells is changed by the presence of metastatic cells. The USPA immunofunctional imaging successfully distinguished metastatic from non-metastatic lymph nodes using biocompatible nanoparticles. This method could aid physicians in the detection of micrometastases, thus guiding SLN biopsy and avoiding unnecessary biopsy procedures.