Variation of sentinel lymphatic channels (SLCs) and sentinel lymph nodes (SLNs) assessed by contrast-enhanced ultrasound (CEUS) in breast cancer patients

Contrast-enhanced ultrasound-guided sentinel lymph node biopsy in early-stage breast cancer: a prospective cohort study

OBJECTIVE

This study evaluated the identification efficiency of contrast-enhanced ultrasound (CEUS) for sentinel lymph nodes (SLN) to accurately represent the axillary node status in early-stage breast cancer.

METHOD

In total, 109 consecutive consenting patients with clinically node-negative and T1-2 breast cancer were included in this study. All patients received CEUS to identify SLN before surgery, and a guidewire was deployed to locate SLN in those who were successfully explored by CEUS. The patients underwent sentinel lymph node biopsy (SLNB), and the blue dye was used to trace SLN during the surgery. The decision to perform axillary lymph node dissection (ALND) depended on the intraoperative pathological identification of SLN by CEUS (CE-SLN). The concordance rate of pathological status between CE-SLN and dyed SLN was calculated.

RESULT

The CEUS detection rate was 96.3%; CE-SLN failed in 4 patients. Among the remaining 105 successful identifications, 18 were CE-SLN positive by intraoperative frozen section, and one with CE-SLN micrometastasis was diagnosed by paraffin section. No additional lymph node metastases were found in CE-SLN-negative patients. The concordance rate of pathological status between CE-SLN and dyed SLN was 100%.

CONCLUSION

CEUS can accurately represent the status of axillary lymph nodes in patients with clinically node-negative and small tumor burden breast cancer.

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.

The value of preoperative sentinel lymph node contrast-enhanced ultrasound for breast cancer: a large, multicenter trial

Objective

The study conducted a multicenter study in China to explore the learning curve of contrast enhanced ultrasound (CEUS) for sentinel lymph nodes (SLNs), the feasibility of using this technique for the localization of SLNs and lymphatic channels (LCs) and its diagnostic performance for lymph node metastasis.

Method

Nine hundred two patients with early invasive breast cancer from six tertiary class hospitals in China were enrolled between December 2016 and December 2019. Each patient received general ultrasound scanning and SLN-CEUS before surgery. The locations and sizes of LCs and SLNs were marked on the body surface based on observations from SLN-CEUS. These body surface markers were then compared with intraoperative blue staining in terms of their locations. The first 40 patients from each center were included in determining the learning curve of SLN-CEUS across sites. The remaining patients were used to investigate the diagnostic efficacy of this technique in comparison with intraoperative blue staining and pathology respectively.

Result

The ultrasound doctor can master SLN-CEUS after 25 cases, and the mean operating time is 22.5 min. The sensitivity, specificity, negative predictive value, and positive predictive value of SLN-CEUS in diagnosing lymph node metastases were 86.47, 89.81, 74.90, and 94.97% respectively.

Conclusion

Ultrasound doctors can master SLN-CEUS with a suitable learning curve. SLN-CEUS is a feasible and useful approach to locate SLNs and LCs before surgery and it is helpful for diagnosing LN metastases.

Contrast-enhanced ultrasound: a new tool for imaging the superficial lymphatic vessels of the upper limb

Background

Despite the new lymphatic imaging methods, there is still a need for a straightforward method of detecting lymphatic abnormalities. Our goal was to investigate the feasibility of applying a contrast enhanced ultrasound (CEUS) procedure as a new approach for visualising the superficial lymphatic vessels of the upper limb.

Methods

Thirty healthy volunteers were examined with CEUS after bilateral intradermal injection of Sonazoid® contrast agent in distal antebrachium. We registered factors affecting intradermal injections, imaging of the superficial lymphatic vessels and the enhancement time of contrast agent reaching the levels of elbow and axilla.

Results

CEUS imaging of superficial lymphatic vessels was successful in 59 of 60 upper limbs (98.3%). Median [interquartile ranges] enhancement times of contrast agent to reach the elbow (right 18 s [11–25], left 15 s [12–25]) and axilla (right 77 s [33–118], left 66 s [42–115]) were equally fast. Successful intradermal injections were found to result in two types of contrast enhancement (strong or moderate), while the enhancement time depended on the type of the successful injection. No major differences in enhancement times were observed related to sex, body mass index, age, or side of the arm.

Conclusions

The superficial lymphatic pathways of the upper limb can be visualised with CEUS imaging. Since enhancement time is dependent on the success of intradermal injections, one must pay attention to the injection technique. Further studies are needed to evaluate the method in patients with lymphatic function disorders such as breast cancer therapy related lymphoedema.

Advanced diagnostic imaging of sentinel lymph node in early stage breast cancer

Sentinel lymph node biopsy has been regarded as the standard procedure for early staging breast cancer. One of the key steps is to locate the sentinel lymph node (SLN). The recommended method is the joint use of blue dye and radioisotope. However, due to radionuclide radiation and high cost, it is urgent to develop more convenient and sensitive imaging methods to accurately locate SLN. This article discusses the advancement of accurately locating SLN by isotope tracer imaging, magnetic tracer method, computed tomographic lymphography, and trans-lymphatic contrast-enhanced ultrasound, as well as proposing new propose for clinical diagnosis.

Preoperative localization of sentinel lymph nodes using percutaneous contrast-enhanced ultrasonography in patients with breast cancer

BACKGROUND

This study aimed to investigate the feasibility of preoperative identification of sentinel lymph nodes (SLNs) by contrast-enhanced ultrasound (CEUS) for patients with breast cancer.

METHODS

The patients with T1-T2N0M0 breast cancer who were scheduled for primary surgical treatment were recruited. All the patients had received a periareolar intradermal injection of an ultrasonic contrast agent (SonoVue, Bracco, Milan, Italy) followed by an ultrasound to identify contrast-enhanced SLNs. A guidewire was deployed to localize the SLN. Methylene blue stain was used to help trace SLNs during the operation. The identification rate and accuracy rate were recorded. The number of SLNs labeled by two methods was counted and compared using Wilcoxon testing.

RESULTS

A total of 366 SLNs were detected in 72 patients by methylene blue intraoperatively, with a median of 5 lymph nodes [interquartile range (IQR), 4-6] per patient. A total of 95 SLNs were detected in 63 patients (87.5%) by CEUS, with a median of 1 lymph node (IQR, 1-2) per patient. The number of SLNs detected by CEUS was significantly less than that labeled by the methylene blue staining method (Z=-7.362, P=0000). Pathology confirmed 12 single metastases in all the lymph nodes examined, 10 of which were the only lymph node identified by CEUS.

CONCLUSIONS

Periareolar intradermal injection of an ultrasonic contrast agent was an effective and convenient supplementary to localize SLNs. The technique was expected to improve the accuracy of axillary staging with minor surgical trauma and postoperative complications.

Contrast-Enhanced Ultrasound for Precise Sentinel Lymph Node Biopsy in Women with Early Breast Cancer: A Preliminary Study

BACKGROUND

Sentinel lymph node biopsy (SLNB), as a common method for axillary staging of early breast cancer, has gradually attracted people's attention to the false-negative rate and postoperative complications. The aim of the study is to investigate the clinical value of preoperative contrast-enhanced ultrasound (CEUS) for intraoperative SLNB in early breast cancer patients.

METHODS

A total of 201 patients scheduled for SLNB from September 2018 to April 2021 were collected consecutively. Preoperative CEUS was used to identify sentinel lymph nodes (SLN) and lymphatic drainage in breast cancer patients.

RESULTS

The SLN identification rate of CEUS was 93.0% (187/201) and four lymphatic drainage patterns were found: single LC to single SLN (70.0%), multiple LCs to single SLN (8.0%), single LC to multiple SLNs (10.2%), and multiple LCs to multiple SLNs (11.8%). The Sen, Spe, PPV, NPV, AUC of CEUS, US and CEUS + US in diagnosis of SLNs were 82.7%, 80.4%, 73.8%, 87.4%, 0.815; 70.7%, 77.7%, 68.0%, 79.8%, 0.742; and 86.7%, 77.7%, 72.2%, 89.7%, 0.822, respectively. There was no statistically significant difference between the diagnostic performance of CEUS and CEUS + US (p = 0.630).

CONCLUSIONS

CEUS can be used to preoperatively assess the lymphatic drainage patterns and the status of the SLNs in early breast cancer to assist precision intraoperative SLNB.

Axillary ultrasound and fine-needle aspiration cytology to predict clinically relevant nodal burden in breast cancer patients

Background

Axillary lymph node involvement is one important prognostic factor in breast cancer, but the way to access this information has been modified over the years. This study evaluated if axillary ultrasound (US) coupled with fine-needle aspiration cytology (FNAC) can accurately predict clinically relevant node metastasis in patients with breast cancer, and thus assist clinical decisions

Methods

This is a cross-sectional study with retrospective data collection of 241 individuals (239 women and 2 men) with unilateral operable breast cancer who were submitted to preoperative axillary assessment by physical exam, US and FNAC if suspicious nodes by imaging. We calculated sensitivity, specificity, and accuracy of the methods. We compared the patient's characteristics using chi-square test, parametrics and non-parametrics statistics according to the variable.

Results

The most sensible method was US (0.59; 95% CI, 0.50–0.69), and the most specific was US coupled with FNAC (0.97; 95% CI, 0.92–0.99). Only 2.7% of the patients with normal axillary US had more than 2 metastatic nodes in the axillary lymph node dissection, against 50% of the patients with suspicious lymph nodes in the US and positive FNAC.

Conclusions

Axillary US coupled with FNAC can sort patients who have a few metastatic nodes at most from those with heavy axillary burden and could be one more tool to initially evaluate patients and define treatment strategies.

The combination of contrast-enhanced ultrasonography with blue dye for sentinel lymph node detection in clinically negative node breast cancer

PURPOSE

The aim of this prospective study was to evaluate the value of the combination of contrast-enhanced ultrasonography (CEUS) and blue dye (BD) for SLN detection in patients with clinically negative node breast cancer.

METHODS

Patients with clinically negative node breast cancer were randomized into two cohorts for SLN biopsy (SLNB): the combination method cohort using CEUS and BD together, and the single BD method cohort. Standard axillary lymph node dissection was performed if any of the SLNs confirmed positive by pathology. The identification rate, the number of SLNs removed and recurrence-free survival (RFS) rates were evaluated between two cohorts. In addition, we assessed the sensitivity, specificity, accuracy, false-negative rate of CEUS for diagnosis of SLNs based on patterns of CEUS enhancement.

RESULTS

144 consecutive patients with clinically negative node breast cancer were randomized into two cohorts. Each cohort consisted of 72 cases. In the combination method cohort, contrast-enhanced lymphatic vessels were clearly visualized and SLNs were accurately localized in 72 cases. The identification rate and the mean number of SLNs detected by the combination method were 100% (72/72) and 3.26 (1-9), respectively. In contrast, in the single BD method cohort, SLNs in 69 cases were successfully identified. The identification rate and the mean number of SLNs using BD alone were 95.8% (69/72) and 2.21 (1-4), respectively. According to patterns of CEUS enhancement, the sensitivity, specificity, accuracy, and the FNR of CEUS for SLN diagnosis were 69.2%, 96.6%, 91.7%, and 30.8%, respectively. After a median follow-up of 50 months for the combination method cohort and 51 months for the blue dye alone cohort, five patients in the combination method cohort and nine in the blue dye alone cohort had recurrence. RFS rates showed no significant difference (P = 0.26) between two cohorts.

CONCLUSION

The combination of CEUS and BD is more effective than BD alone for SLNB in clinically negative node patients with an identification rate as high as 100%. Use of BD and CEUS in combination may provide the possibility of a non-radioactive alternative method for SLNB in centers without access to radioisotope.

Analysis of Contrast-Enhanced Ultrasound and Elastography in the Diagnosis of Benign and Malignant Apocrine Breast Tumors

In the past thirty years, breast cancer in women has continued to rise. The age of onset for women has become lower. Contrast-enhanced ultrasound (CEUS) can clearly show the blood perfusion and neovascularization of breast masses. Elastography provides information on the stiffness of tissues. The combination of them shows a good advantage in the various early diagnosis of breast cancer. The combined electrograph can distinguish benign and malignant apocrine breast tumors. The shear wave electrograph (SWE) combined with CEUS has the strongest consistency in the diagnosis and pathology of breast benign tumors. When they were diagnosed separately, it was found that SWE has higher diagnostic value than CEUS; the quantitative diagnosis of SWE is slightly higher than the qualitative diagnosis, and the qualitative diagnosis of CEUS is higher than the quantitative diagnosis. Both SWE and CEUS are valuable in the diagnosis of benign and malignant apocrine breast tumor when combined treatment is made.

False-negative frozen section of sentinel nodes in early breast cancer (cT1-2N0) patients

Background

Sentinel lymph node biopsy (SLNB) is the standard approach for the axillary region in early breast cancer patients with clinically negative nodes. The present study investigated patients with false-negative sentinel nodes in intraoperative frozen sections (FNSN) using real-world data.

Methods

A case–control study with a 1:3 ratio was conducted. FNSN was determined when sentinel nodes (SNs) were negative in frozen sections but positive for metastasis in formalin-fixed paraffin-embedded (FFPE) sections. The control was defined as having no metastasis of SNs in both frozen and FFPE sections.

Results

A total of 20 FNSN cases and 60 matched controls from 333 SLNB patients were enrolled between April 1, 2005, and November 31, 2009. The demographics and intrinsic subtypes of breast cancer were similar between the FNSN and control groups. The FNSN patients had larger tumor sizes on preoperative mammography (P = 0.033) and more lymphatic tumor emboli on core biopsy (P < 0.001). Four FNSN patients had metastasis in nonrelevant SNs. Another 16 FNSN patients had benign lymphoid hyperplasia of SNs in frozen sections and metastasis in the same SNs from FFPE sections. Micrometastasis was detected in seven of 16 patients, and metastases in nonrelevant SNs were recognized in two patients. All FNSN patients underwent a second operation with axillary lymph node dissection (ALND). After a median follow-up of 143 months, no FNSN patients developed breast cancer recurrence. The disease-free survival, breast cancer-specific survival, and overall survival in FNSN were not inferior to those in controls.

Conclusions

Patients with a larger tumor size and more lymphatic tumor emboli have a higher incidence of FNSN. However, the outcomes of FNSN patients after completing ALND were noninferior to those without SN metastasis. ALND provides a correct staging for patients with metastasis in nonsentinel axillary lymph nodes.

Comparative study of two contrast agents for intraoperative identification of sentinel lymph nodes in patients with early breast cancer

Background

The use of contrast-enhanced ultrasound (CEUS) to locate sentinel lymph nodes (SLNs) in breast cancer has been studied more and more in recent years. This prospective study aimed to compare periareolar injection of two different contrast agents, SonoVue^® (SNV) and Sonazoid^® (SNZ), followed by CEUS to identify SLNs in breast cancer patients with clinically negative nodes.

Methods

A total of 205 patients with T1-2N0M0 breast cancer were divided into the SNV group and SNZ group. All were administered a periareolar injection of SNV or SNZ and underwent US to identify contrast-enhanced SLNs. Each contrast-enhanced SLN underwent a biopsy with blue dye and examined again by CEUS in vitro.

Results

In all cases, contrast-enhanced lymphatic vessels were clearly visualized using US soon after the periareolar injection of SNZ, and the SLNs were easily identified. The SLN identification rates were 75.27% (210/279) for SNV and 93.58% (102/109) for SNZ. Although the accuracy of detecting SLN metastasis was slightly different between the two groups, there was no statistically significant difference between those groups (P=0.615). Moreover, it was possible to identify SLNs in vitro in the SNZ group, and these could be compared with the lymph nodes (LNs) located using SNZ during the preoperative stage and with blue dye during the procedure. This helped in determining the resection requirements.

Conclusions

When comparing the subdermal use of SNV and SNZ, no significant differences in the number of detected SLNs and the diagnosis of metastatic LNs were observed. Because SLNs can be detected for a longer time in living tissues with SNZ, this contrast agent may provide more intraoperative information for complete resection of all preoperative localization of SLN.

Contrast-enhanced US for the Interventional Radiologist: Current and Emerging Applications

US is a powerful and nearly ubiquitous tool in the practice of interventional radiology. Use of contrast-enhanced US (CEUS) has gained traction in diagnostic imaging given the recent approval by the U.S. Food and Drug Administration (FDA) of microbubble contrast agents for use in the liver, such as sulfur hexafluoride lipid-type A microspheres. Adoption of CEUS by interventional radiologists can enhance not only procedure guidance but also preprocedure patient evaluation and assessment of treatment response across a wide spectrum of oncologic, vascular, and nonvascular procedures. In addition, the unique physical properties of microbubble contrast agents make them amenable as therapeutic vehicles in themselves, which can lay a foundation for future therapeutic innovations in the field in drug delivery, thrombolysis, and vascular flow augmentation. The purpose of this article is to provide an introduction to and overview of CEUS aimed at the interventional radiologist, highlighting its role before, during, and after frequently practiced oncologic and vascular interventions such as biopsy, ablation, transarterial chemoembolization, detection and control of hemorrhage, evaluation of transjugular intrahepatic portosystemic shunts (TIPS), detection of aortic endograft endoleak, thrombus detection and evaluation, evaluation of vascular malformations, lymphangiography, and percutaneous drain placement. Basic physical principles of CEUS, injection and scanning protocols, and logistics for practice implementation are also discussed. Early adoption of CEUS by the interventional radiology community will ensure rapid innovation of the field and development of future novel procedures. Online supplemental material is available for this article. ^©RSNA, 2020.

Preoperative evaluation and influencing factors of sentinel lymph node detection for early breast cancer with contrast-enhanced ultrasonography: What matters

Sentinel lymph node (SLN) is important in the early diagnosis of breast cancer. We aimed to evaluate the role of contrast-enhanced ultrasonography (CEUS) in the preoperative evaluation for SLN and potentially influencing factors, to provide evidence to the management of breast cancer.Patients with breast cancer who treated in our hospital from May 2018 to May 2020 were selected. All patients underwent CEUS examination to find SLN and judged whether the lymph node had cancer metastasis. We evaluated the sensitivity, specificity, and accuracy of CEUS in predicting SLN, and its differences in pathological diagnosis results and related influencing factors were also analyzed.A total of 108 patients with breast cancer were included. And a total of 248 SLNs were detected. The sensitivity of CEUS to the preoperative evaluation of SLN was 84.67%, the specificity was 81.14%, the positive predictive value was 76.08%, and the negative predictive value was 89.27%, the positive likelihood ratio was 4.06, and the negative likelihood ratio was 0.14. The area under the curve of the preoperative evaluation of SLN in CEUS examination was 0.813 (95% confidence interval: 0.765-0.911), and there was significant difference in the size of SLNs between SLN-negative and SLN-positive groups (P = .043).Preoperative CEUS has good predictive value for the SLN detection in patients with breast cancer, and it is worthy of clinical application.

The value of contrast-enhanced ultrasound in determining the location of sentinel lymph nodes in breast cancer

Background

This study aimed to explore the sentinel lymph node (SLN) identification rate in breast cancer by subcutaneous and intradermal injection of ultrasound contrast agent in the mammary areola region, compared to the results achieved with methylene blue (MB).

Methods

A total of 390 breast cancer patients with planned sentinel lymph node biopsy from our breast surgery department from July 2017 to February 2019 were enrolled. All patients were subjected to preoperative contrast-enhanced ultrasound (CEUS), that involved an intracutaneous injection of 1 mL ultrasonic contrast agent (UCA) at 3 and 6 o ‘clock, as well as a subcutaneous injection of 1 mL UCA at 9 and 12 o’clock. The enhanced lymph nodes along the enhanced lymphatic vessels from the mammary areola were traced. The number of enhanced lymph nodes were recorded, and an ultrasound-guided injection of 1:10 diluted carbon nanoparticles were used to mark all first site enhanced lymph nodes (i.e., SLNs). An intraoperative dye method (MB) was used to track the SLNs and the results were compared with the CEUS findings.

Results

Among the 390 cases of breast cancer, enhanced SLNs were observed in 373 patients after an injection of UCA with an identification rate of 95.64 % (373/390), compared to the identification rate of 92.05 % (359/390) using the intraoperative MB. The difference between the two methods was statistically significant (P = 0.016). And among the 390 patients, a total of 808 enhanced lymph nodes were traced by preoperative CEUS, with a median of 2 (1,3). A total of 971 blue-stained lymph nodes were traced using the intraoperative MB, with a median of 2 (2,3), indicating a statistically significant difference (p < 0.001).

Conclusions

Intradermal and subcutaneous injections of UCA in the mammary areola region may have clinical application value for the identification and localization of SLNs in breast cancer patients. The identification rate is higher than that of blue dye method, which can be used as a new tracer of sentinel lymph node biopsy and complement other staining methods to improve the success rate.

Preoperative Contrast-Enhanced Ultrasound (CEUS) Combined with 125I Seeds Localization in Sentinel Lymph Node Biopsy for Breast Cancer

Objective

To assess the clinical value of contrast-enhanced ultrasound (CEUS) technology in predicting axillary lymph nodes status before surgery, and to explore the feasibility of sentinel lymph nodes (SLNs) localization guided by CEUS combined with ¹²⁵I implantation for breast cancer.

Methods

From August 2017 to February 2019, 115 patients were included in this prospective study. Before surgery, a microbubble (SonoVue) was injected intradermally next to the areola. The enhancement patterns of SLNs were recorded and ¹²⁵I seeds were deployed into the enhanced nodes. Then, all patients underwent standard sentinel lymph node biopsy (SLNB) and all ¹²⁵I seeds were found out guided by a gamma detector in surgery. The localization was considered successful if ¹²⁵I seeds were implanted in/beside the nodes.

Results

SLNs in 103 cases were successfully identified, the success rate was 89.6% (103/115), 118 SLNs were detected in total. ¹²⁵I seeds were deployed successfully in 99 cases, and all of the ¹²⁵I-labeled SLNs were then successfully detected by combined method (radionuclides and blue dye). The accuracy of ¹²⁵I seeds localization was 96.1% (99/103). Based on the enhancement patterns recorded, 34 cases were predicted to have SLNs metastasis (metastasis in 27 cases and no metastasis in 7 cases confirmed by postoperative pathology) and 65 cases were predicted to have no SLNs metastasis (metastasis in 5 cases and no metastasis in 60 cases by pathology). The positive predictive value and negtive predictive value of CEUS in assessing axillary status were 79.4% (27/34) and 92.3% (60/65), respectively. The axillary metastasis rate in CEUS combined with ¹²⁵I seeds localization was 27.3% (27/99), while the metastasis rate in the combined method of SLNB was 32.3% (32/99). The sensitivity of ¹²⁵I seeds localization was 84.4% (27/32), the false-negative rate was 15.6% (5/32), and the consistency evaluation was excellent (Kappa value=0.880, P<0.001).

Conclusion

CEUS combined with ¹²⁵I seeds implantation can locate SLNs accurately and has excellent consistency with the combined method. The enhancement patterns can provide helpful predicting information of axillary status preoperatively. However, more studies are needed to be carried out to verify our outcomes and explore the feasibility of applying CEUS technology in clinical work.

Predictive risk factors for sentinel lymph node metastasis using preoperative contrast-enhanced ultrasound in early-stage breast cancer patients

Background

Sentinel lymph node biopsy (SLNB) is the standard procedure for axillary staging in clinically node-negative (cN0) breast cancer patients. The positive rate of SLNs in cN0 stage patients ranges from 20.5% to 25.5%, so identifying appropriate candidates for SLNB is quite challenging. The aims of this study were to assess whether contrast-enhanced ultrasound (CEUS) could be utilized to noninvasively predict SLN metastasis, and to explore the predictive value of the involved factors.

Methods

Between May 2016 and May 2018, 217 consenting breast cancer patients undergoing SLNB were enrolled. Before the surgery, CEUS was utilized to identify the SLNs, and predict whether metastasis had occurred according to their enhancement pattern. Blue dye was also used to identify the SLNs during SLNB. The rates of identification and accuracy of both methods were recorded. The predictive outcomes of SLNs identified by CEUS were recorded and compared with the pathological diagnosis.

Results

Of the 217 cases, SLNs in 212 cases were successfully identified, comprising 208 cases identified by CEUS and 206 cases by blue dye, with no significant difference between the two methods (P=0.6470). A total of 78 cases were predicted SLN-positive preoperatively by CEUS, comprising 61 cases of SLN metastasis confirmed by pathology and 17 cases of no SLN metastasis, and 130 cases were predicted SLN-negative by CEUS, comprising 6 cases of SLN metastasis and 124 cases of no SLN metastasis. The sensitivity of CEUS preoperative prediction was 91.0%, the specificity was 87.9%, the positive and negative predictive values were 78.2% and 95.4%, respectively, and the accuracy was 88.9%. The maximum diameter size of positive SLNs predicted by CEUS was greater than that of negative SLNs (mean value 1.67±0.06 vs. 1.40±0.05 cm, P=0.0007). Similarly, the primary tumor size predicted SLN-positive by CEUS was greater than that in patients with negative SLNs (mean value 2.64±0.12 vs. 1.79±0.09 cm, P<0.0001).

Conclusions

CEUS accurately identified SLNs and can be used to noninvasively predict SLN metastasis in early-stage breast cancer patients. However, the primary tumor size and the SLN size should not be overlooked by clinicians when judging the status of SLNs. This novel method may be a recommended strategy for identifying appropriate SLNB candidates.

Contrast-Enhanced Ultrasonography in the Diagnosis and Treatment Modulation of Breast Cancer

The aim of this paper is to highlight the role of contrast-enhanced ultrasound in breast cancer in terms of diagnosis, staging and follow-up of the post-treatment response. Contrast-enhanced ultrasound (CEUS) is successfully used to diagnose multiple pathologies and has also clinical relevance in breast cancer. CEUS has high accuracy in differentiating benign from malignant lesions by analyzing the enhancement characteristics and calculating the time-intensity curve’s quantitative parameters. It also has a significant role in axillary staging, especially when the lymph nodes are not suspicious on clinical examination and have a normal appearance on gray-scale ultrasound. The most significant clinical impact consists of predicting the response to neoadjuvant chemotherapy, which offers the possibility of adjusting the therapy by dynamically evaluating the patient. CEUS is a high-performance, feasible, non-irradiating, accessible, easy-to-implement imaging method and has proven to be a valuable addition to breast ultrasound.

Ultrasonographic Algorithm for the Assessment of Sentinel Lymph Nodes That Drain the Mammary Carcinomas in Female Dogs

The status of sentinel lymph nodes (SLNs) is decisive in staging, prognosis, and therapeutic approach. Using an ultrasonographic examination algorithm composed of B-mode, Doppler technique, contrast-enhanced ultrasound (CEUS) and elastography, this study aimed to determine the diagnostic performance of the four techniques compared to histopathological examination. 96 SLNs belonging to 71 female dogs with mammary gland carcinomas were examined. After examinations, mastectomy and lymphadenectomy were performed. Histopathological examination confirmed the presence of metastases in 54 SLNs. The elasticity score had the highest accuracy-89.71%, identifying metastases in SLNs with 88.9.9% sensitivity (SE) and 90.5% specificity (SP), ROC analysis providing excellent results. The S/L (short axis/long axis) ratio showed 83.3% SE and 78.6% SP as a predictor of the presence of metastases in SLN having a good accuracy of 81.2%. On Doppler examination, the resistivity index(RI) showed good accuracy of 80% in characterizing lymph nodes with metastases versus unaffected ones; the same results being obtained by CEUS examination. By assigning to each ultrasonographic parameter a score (0 or 1) and summing up the scores of the four techniques, we obtained the best diagnostic performance in identifying lymph node metastases with 92.2% accuracy. In conclusion, the use of the presented algorithm provides the best identification of metastases in SLNs, helping in mammary carcinoma staging and appropriate therapeutic management.

New technologies in breast cancer sentinel lymph node biopsy; from the current gold standard to artificial intelligence

Sentinel lymph node biopsy is an important diagnostic procedure performed in early breast cancer patients with clinically negative axillary lymph nodes. Detection and examination of sentinel lymph nodes determine further therapy decisions, therefore a choice of optimal technique minimising the risk of false-negative results is of great importance. Currently, the gold standard is the dual technique comprising the blue dye and radiotracer, however, this method creates a logistical problem for many medical units. The intrinsic constraints of the existing methods led to the development of a very wide range of alternatives with varying clinical efficiency and feasibility. While each method presents with its own advantages and disadvantages, many techniques have improved enough to become a non-inferior alternative in the sentinel lymph node biopsy. Along with the improvement of the existing technologies, there are evolving trends such as multimodality of the techniques maximising the diagnostic outcome or an emerging use of artificial intelligence (AI) improving the workflow of the procedure. This literature review aims to give an overview of the current status of the standard techniques and emerging cutting-edge technologies in the sentinel lymph node biopsy.

Contrast-enhanced ultrasonography and blue dye methods in detection of sentinel lymph nodes following neoadjuvant chemotherapy in initially node positive breast cancer

BACKGROUND

Recent studies show that contrast-enhanced ultrasonography (CEUS) using SonoVue has the potential to improve the performance of sentinel lymph node biopsy (SLNB) in patients with early breast cancer. However, the evidence of SLNB using CEUS in patients converting from cN1 to cN0 after neoadjuvant chemotherapy (NAC) is lacking. The aim of this prospective study is to evaluate the feasibility of CEUS using SonoVue for the identification of sentinel lymph node (SLN) and the value of the combination of CEUS and blue dye (BD) for SLNB in patients converting from cN1 to cN0 following NAC.

METHODS

Patients with cytology-proven node positive breast cancer at the initial diagnosis (stage T1-T3N1M0) from January 2018 to January 2019, underwent NAC. Patients converting from cN1 to cN0 following NAC were enrolled and randomized into two groups for SLNB: the combination method group using CEUS and BD together, and the single BD method group. Then all patients underwent complete axillary lymph node dissection (ALND) and primary breast surgery. Compared with the final pathological results, the identification rate, sensitivity, specificity, accuracy, false negative rate, negative predictive value, positive predictive value were recorded and compared between two methods.

RESULTS

A total of 400 patients with stage T1-T3N1M0 disease underwent NAC between January 2018 to January 2019, among which 134 (33.5%) patients had clinically negative node confirmed by imaging after NAC and randomized into two groups. Each group included 67 cases. In the combination method group, contrast-enhanced lymphatic vessels in 66 cases of 67 were clearly visualized by US soon after the periareolar injection of SonoVue and the SLNs were accurately localized. The identification rate of the combination method was 98.5%%, which was significantly higher than 83.6% (56/67) using the single BD method. The mean numbers of SLNs identified by the combination method was higher than that by the single BD method. Compared with pathological diagnosis, sensitivity, specificity, accuracy, the positive predictive value, the negative predictive value, and the FNR of the combingation method were 84.4%, 100%, 89.4%, 100%, 75%, and 15.6%, respectively. In contrast, sensitivity, specificity, accuracy, the positive predictive value, the negative predictive value, and the FNR using single blue dye were 73.9%, 100%, 89.3%, 100%, 84.6%, and 26.1%, respectively. The FNR using the combination method was significantly lower than that using single BD.

CONCLUSION

Identification of SLNs in patients converting from cN1 to cN0 following NAC by CEUS is a technically feasible. The combination of CEUS and BD is more effective than BD alone for SLNB in patients converting from cN1 to cN0 following NAC.

Accuracy of CEUS-guided sentinel lymph node biopsy in early-stage breast cancer: a study review and meta-analysis

Objective

To investigate whether preoperative localization of sentinel lymph node (SLN) by contrast-enhanced ultrasound (CEUS) can further improve the accuracy of sentinel lymph node biopsy (SLNB).

Method

Collect published literatures or conference reports by searching electronic databases. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) evaluation method is used to evaluate the quality of the screened literatures. The pooled risk ratio of cancer metastasis of SLN identified by CEUS (CE-SLN) compared with SLN not identified by CEUS (nonCE-SLN) is calculated, and the pooled diagnostic accuracy of CE-SLN for pathological status of all SLNs is also evaluated.

Result

Through search and screening, a total of 16 studies were included, of which five and seven studies, respectively, entered the meta-analysis of metastatic risk ratio and diagnostic accuracy. The localization rate of preoperative CEUS for sentinel lymph nodes was 70 to 100%. The meta-analysis shows that the risk of metastasis of SLN identified by CEUS is significantly higher than that not identified by CEUS, 26.0% vs 4.6%, and risk ratio (RR) is 6.08 (95% CI 4.17–8.85). In early-stage breast cancer, the pathological status of CE-SLN is a good representative of all SLNs, with a pooled sensitivity of 98% (95% CI 0.94–1.00), pooled specificity of 100% (95% CI 0.99–1.00), diagnostic odds ratio (DOR) of 2153.18 (95% CI 476.53–9729.06), and area under the subject receiver operating characteristic (SROC) curve of 0.9968.

Conclusion

In early-stage breast cancer, preoperative localization of SLN by CEUS is expected to further improve the accuracy of sentinel lymph node biopsy (SLNB).

Preliminary study of real-time three-dimensional contrast-enhanced ultrasound of sentinel lymph nodes in breast cancer

PURPOSE

To investigate the clinical value of real-time three-dimensional contrast-enhanced ultrasound (3D-CEUS) in the detection of sentinel lymph nodes (SLNs) and drainage lymphatics in breast cancer patients.

METHOD

The prospective study was performed in women with pathology-confirmed T1/2 breast cancer between June 2016 and December 2017 who underwent sentinel lymph node biopsy and 3D-CEUS. The number, size, location, enhancement pattern of SLNs, and the lymphatic drainage patterns were reviewed. The routes, location of SLNs, and lymph channels (LCs) on the surface were marked. All patients underwent blue dye-guided sentinel lymph node biopsy (SLNB) finally.

RESULTS

According to the postoperative pathology findings and the blue dye staining of the lymphatic drainage routes, there are six patterns of lymphatic drainage routes and the coincidence rate of the 3D-CEUS was 97.4%; the sensitivity, specificity, positive predictive value, negative predictive value, the LN detection rate, and the correct diagnosis rate of the 3D-CEUS were 75%, 93.0%, 81.8%, 89.9%, 95.3%, and 87.7%, respectively.

CONCLUSION

3D-CEUS is a new feasible and useful approach to detect the SLNs and LCs. 3D-CEUS can accurately localize the LCs and SLNs and estimate the presence of metastatic lymph nodes.

KEY POINTS

• The three-dimensional contrast-enhanced ultrasound can detect the sentinel lymph nodes. • The three-dimensional contrast-enhanced ultrasound can show the stereo direction of sentinel lymph nodes and lymph drainage routes. • The three-dimensional contrast-enhanced ultrasound can accurately localize the LCs and SLNs and estimate the presence of metastatic lymph nodes.

Real-Time Visualization of Lymphatic Flow to Sentinel Lymph Nodes by Contrast-Enhanced Ultrasonography with Sonazoid in Patients with Breast Cancer

Contrast-enhanced ultrasonography with Sonazoid (SNZ) enables real-time visualization, resulting in more precise identification of lymphatic flow to sentinel lymph nodes (SLNs). This study aimed to classify lymphatic drainage patterns to SLNs. Patients (n = 75) with T1-2 N0 M0 breast cancer received a periareolar injection of SNZ to identify SNZ-enhanced SLNs (SNZ-SLNs), followed by SLN biopsy with blue dye. The lymphatic drainage patterns were classified into four types: type A, single lymphatic route/single SLN; type B, multiple lymphatic routes/single SLN; type C, single lymphatic route/multiple SLNs; and type D, multiple lymphatic routes/multiple SLNs. SLNs were successfully identified in all patients using both blue dye and SNZ. The drainage lymphatic pathways identified were as follows: type A in 53 cases (70.7%), type B in seven (9.3%), type C in eight cases (10.7%) and type D in seven (9.3%). SNZ-SLN biopsy is a technically simple method with a 100% identification rate, enabling the real-time visualization of lymphatic flow to SNZ-SLNs.

Network meta-analysis of novel and conventional sentinel lymph node biopsy techniques in breast cancer

Background

The aim of this network meta‐analysis was to compare the performance of blue dye alone or in combination with radioisotope (technetium‐99m, Tc) with three novel techniques for sentinel lymph node detection in breast cancer: indocyanine green fluorescence (ICG), superparamagnetic iron oxide (SPIO) nanoparticles and contrast‐enhanced ultrasound imaging (CEUS).

Methods

PubMed, Embase, the Cochrane Library, China Knowledge Research Integrated Database, ClinicalTrials.gov and OpenGrey databases were searched up to 31 November 2017, without language restriction. Studies that compared the detection performance of at least one of the novel methods (ICG, SPIO and CEUS) with that of traditional methods (blue dye and/or radioisotope) were included in network meta‐analysis.

Results

Thirty‐five studies were included. Pooled risk ratios (RRs) for Tc (1·09, 95 per cent c.i. 1·04 to 1·15), ICG (1·12, 1·07 to 1·16) and SPIO (1·09, 1·01 to 1·18) showed statistically better performance in detecting sentinel lymph nodes than blue dye alone. ICG had the lowest false‐negative rate, with a RR of 0·29 (0·16 to 0·54), followed by Tc (RR 0·44, 0·20 to 0·96) and SPIO (RR 0·45, 0·14 to 1·45), with blue dye alone as the reference group.

Conclusion

SPIO or ICG alone are superior to blue dye alone and comparable to the standard dual‐modality technique of blue dye with Tc.