Contrast-enhanced sonography for detection of secondary lymph nodes in a melanoma tumor animal model

Characterizing Sentinel Lymph Node Status in Breast Cancer Patients Using a Deep-Learning Model Compared With Radiologists' Analysis of Grayscale Ultrasound and Lymphosonography

ABSTRACT

The objective of the study was to use a deep learning model to differentiate between benign and malignant sentinel lymph nodes (SLNs) in patients with breast cancer compared to radiologists' assessments.Seventy-nine women with breast cancer were enrolled and underwent lymphosonography and contrast-enhanced ultrasound (CEUS) examination after subcutaneous injection of ultrasound contrast agent around their tumor to identify SLNs. Google AutoML was used to develop image classification model. Grayscale and CEUS images acquired during the ultrasound examination were uploaded with a data distribution of 80% for training/20% for testing. The performance metric used was area under precision/recall curve (AuPRC). In addition, 3 radiologists assessed SLNs as normal or abnormal based on a clinical established classification. Two-hundred seventeen SLNs were divided in 2 for model development; model 1 included all SLNs and model 2 had an equal number of benign and malignant SLNs. Validation results model 1 AuPRC 0.84 (grayscale)/0.91 (CEUS) and model 2 AuPRC 0.91 (grayscale)/0.87 (CEUS). The comparison between artificial intelligence (AI) and readers' showed statistical significant differences between all models and ultrasound modes; model 1 grayscale AI versus readers, P = 0.047, and model 1 CEUS AI versus readers, P < 0.001. Model 2 r grayscale AI versus readers, P = 0.032, and model 2 CEUS AI versus readers, P = 0.041.The interreader agreement overall result showed κ values of 0.20 for grayscale and 0.17 for CEUS.In conclusion, AutoML showed improved diagnostic performance in balance volume datasets. Radiologist performance was not influenced by the dataset's distribution.

Identification of sentinel lymph nodes in esophageal cancer patients using contrast-enhanced EUS with peritumoral injections

Objectives

The objective of this pilot study was to compare the performance of contrast-enhanced EUS (CE-EUS)-guided fine-needle aspiration (FNA) with EUS-FNA for lymph node (LN) staging in esophageal cancer.

Methods

Thirty-seven subjects with esophageal cancer undergoing EUS staging were enrolled, and 30 completed this institutional review board-approved study. A Prosound F75 US system (Hitachi Medical Systems, Tokyo, Japan) with harmonic contrast imaging software and GF-UCT180 curvilinear endoscope (Olympus, Tokyo, Japan) was utilized. All LNs identified by standard EUS were first noted. Sonazoid (dose: 1 mL; GE Healthcare, Oslo, Norway) was administered peritumorally, and all enhanced LNs were recorded. Fine-needle aspiration was performed on LNs considered suspicious by EUS alone, as well as LNs enhanced on CE-EUS. Performance of each modality was compared using FNA cytology as reference standard.

Results

A total of 132 LNs were detected with EUS, of which 59 showed enhancement on CE-EUS. Fifty-three LNs underwent FNA, and 22 LNs were determined to be malignant. Among the latter, 10 were considered suspicious by EUS, whereas the other 12 LNs underwent FNA only because of CE-EUS enhancement. Contrast-enhanced EUS showed enhancement in 19 of the 22 malignant LNs. The rate of metastatic node identification from EUS was 45% (10/22), and it was 86% (19/22; P = 0.008) for CE-EUS. Eight subjects (8/30 [27% of study total]) had nodal status upgraded by the addition of CE-EUS, which influenced LN staging and clinical management.

Conclusions

Fine-needle aspiration of LNs identified by CE-EUS may increase metastasis positive rate by ruling out LNs not associated with the tumor drainage pattern. In addition, CE-EUS seems to identify more metastatic LNs that would not be biopsied under the standard EUS criteria.

Sentinel Lymph Node Identification in Post Neoadjuvant Chemotherapy Breast Cancer Patients Undergoing Surgical Excision Using Lymphosonography

OBJECTIVES

This study evaluated the efficacy of lymphosonography in the identification of sentinel lymph nodes (SLNs) in post neoadjuvant chemotherapy patients with breast cancer scheduled to undergo surgical excision.

METHODS

Seventy-nine subjects scheduled for breast cancer surgery with SLN excision completed this IRB-approved study, out of which 18 (23%) underwent neoadjuvant chemotherapy before surgery. Subjects underwent percutaneous Sonazoid (GE Healthcare) injections around the tumor area for a total of 1.0 mL. Lymphosonography was performed using CPS on an S3000 HELX scanner (Siemens Healthineers) with a linear probe. Subjects received blue dye and radioactive tracer as part of their standard of care. Excised SLNs were classified as positive or negative for the presence of blue dye, radioactive tracer and Sonazoid. The results were compared between methods and pathology findings.

RESULTS

Seventy-two SLNs were surgically excised from 18 subjects, 29 were positive for blue dye, 63 were positive for radioactive tracer and 57 were positive for Sonazoid. Comparison with blue dye showed that both radioactive tracer and lymphosonography achieved an accuracy of 53% (P > .50). Comparison with radioactive tracer showed that blue dye had an accuracy of 53%, while lymphosonography achieved an accuracy of 67% (P < .01). Of the 72 SLNs, 15 were determined malignant by pathology; the detection rate was 47% for blue dye (7/15), 67% for radioactive tracer (10/15) and 100% for lymphosonography (15/15) (P < .001).

CONCLUSIONS

Lymphosonography achieved similar accuracy as radioactive tracer and higher accuracy than blue dye for identifying SLNs. The 15 SLNs positive for malignancy were all identified by lymphosonography.

Anatomy Versus Physiology: Is Breast Lymphatic Drainage to the Internal Thoracic (Internal Mammary) Lymphatic System Clinically Relevant?

Approximately 15%-25% of breast lymphatic drainage passes through the internal thoracic (internal mammary) lymphatic system, draining the inner quadrants of the breast. This study aimed to use lymphosonography to identify sentinel lymph nodes (SLNs) in the axillary and internal thoracic lymphatic systems in patients with breast cancer. Seventy-nine patients received subcutaneous ultrasound contrast agent injections around the tumor. Lymphosonography was used to identify SLNs. In 14 of the 79 patients (17.7%), the tumor was located in the inner quadrant of the breast. Lymphosonography identified 217 SLNs in 79 patients, averaging 2.7 SLNs per patient. The 217 identified SLNs in the 79 patients were located in the axillary lymphatic system; none were located in the internal thoracic (internal mammary) lymphatic system, although it was expected in two to four patients (i.e., 4-11 SLNs). These results implied that SLNs associated with breast cancer are predominantly located in the axillary lymphatic system.

Sentinel Lymph Node Identification in Patients With Breast Cancer Using Lymphosonography

The objective of the work described here was to evaluate the efficacy of lymphosonography in identifying sentinel lymph nodes (SLNs) in patients with breast cancer undergoing surgical excision. Of the 86 individuals enrolled, 79 completed this institutional review board-approved study. Participants received subcutaneous 1.0-mL injections of ultrasound contrast agent (UCA) around the tumor. An ultrasound scanner with contrast-enhanced ultrasound (CEUS) capabilities was used to identify SLNs. Participants were administered with blue dye and radioactive tracer to guide SLN excision as standard-of-care. Excised SLNs were classified as positive or negative for the presence of blue dye, radioactive tracer and UCA, and sent for pathology. Two hundred fifty-two SLNs were excised; 158 were positive for blue dye, 222 were positive for radioactive tracer and 223 were positive for UCA. Comparison with blue dye revealed accuracies of 96.2% for radioactive tracer and 99.4% for lymphosonography (p > 0.15). Relative to radioactive tracer, blue dye had an accuracy of 68.5%, and lymphosonography achieved 86.5% (p < 0.0001). Of 252 SLNs excised, 34 were determined to be malignant by pathology; 18 were positive for blue dye (detection rate = 53%), 23 for radioactive tracer (detection rate = 68%) and 34 for UCA (detection rate = 100%) (p < 0.0001). Lymphosonography was similar in accuracy to radioactive tracer and higher in accuracy than blue dye in identifying SLNs. All 34 malignant SLNs were identified by lymphosonography.

Microbubble-Assisted Ultrasound for Imaging and Therapy of Melanoma Skin Cancer: A Systematic Review

Recent technological developments in ultrasound (US) imaging and ultrasound contrast agents (UCAs) have improved diagnostic confidence in echography. In the clinical management of melanoma, contrast-enhanced ultrasound (CEUS) imaging complements conventional US imaging (i.e., high-resolution US and Doppler imaging) for clinical examination and therapeutic follow-up. These developments have set into motion the combined use of ultrasound and UCAs as a new modality for drug delivery. This modality, called sonoporation, has emerged as a non-invasive, targeted and safe method for the delivery of therapeutic drugs into melanoma. This review focuses on the results and prospects of using US and UCAs as dual modalities for CEUS imaging and melanoma treatment.

Percutaneous contrast-enhanced ultrasound for localization and qualitative diagnosis of sentinel lymph nodes in cutaneous malignant melanoma of lower extremities: a preliminary study

Background

To explore the feasibility of sentinel lymph node (SLN) tracing by percutaneous contrast-enhanced ultrasound (pCEUS) in patients with cutaneous malignant melanoma (CMM) and the ability to enhance patterns of SLNs in diagnosing lymph nodes (LNs) metastases.

Methods

Fifty-three patients with CMM of the lower extremities treated at our hospital were included in the study. All the participants received pCEUS preoperatively. The enhanced lymphatic channels (LCs) and associated SLNs were observed and tracked in real-time. The number of enhanced LCs and enhancing patterns of SLNs were recorded. Subsequently, SLNs localized by pCEUS were pathologically examined.

Results

Of the 53 cases, SLNs were successfully localized by pCEUS in 48 cases. In total, there were 59 detected SLNs averaging 1.23±0.42 SLNs per case. The main lymphatic drainage patterns (LDPs) were the following: one enhanced LC pointed to one or more than one SLN, and multiple enhanced LCs pointed to one or multiple SLNs. There were four enhancing patterns of SLNs (uniform, annular, uneven, and no enhancement), among which the first two were considered benign nodes, while the latter two were considered metastatic nodes. With pathological results as the gold standard, the diagnostic sensitivity and specificity by pCEUS were 90.9% and 75.0%, respectively.

Conclusions

Contrast-enhanced ultrasound (US) is a feasible approach for SLN identification in patients with CMM of the lower extremities. Enhancing patterns of SLNs may help predict metastasizing SLNs. This novel method may be a promising technique for clinical application.

Identifying ultrasound features of positive expression of Ki67 and P53 in breast cancer using radiomics

PURPOSE

To examine the relationship between ultrasonic findings and positive expression of Ki67 and P53 in breast cancer.

MATERIAL AND METHODS

Surgical resection specimens of 263 breast cancer lesions were examined. Ultrasound examination and pathological examination were performed on each lesion for retrospective analysis. We applied regression analysis to the ultrasonic features related to the positive expression of Ki67 and P53 and obtained the corresponding models. To analyze diagnostic efficiency, we calculated the area under the curve (AUC). Additionally, we created a heat map to show the results of the cluster analysis.

RESULTS

Lesions with higher Ki67 expression were associated with posterior acoustic enhancement, absence of an echo halo and a higher Breast Imaging Reporting and Data System (BI-RADS) category. P53-positive cancer were associated with an absence of an echo halo and a higher BI-RADS category. The AUC of the regression models of Ki67 and P53 was 0.78 and 0.71, respectively.

CONCLUSIONS

Our study revealed that breast cancer ultrasonic findings were closely related to expression of molecular indicators, suggesting that ultrasound can be used to provide useful information to clinicians.

Upper limb secondary lymphedema ultrasound mapping and characterization

BACKGROUND

Ultrasound investigation potentials in lymphedema are still to be fully used in everyday practice. Aim of the present study was to report the sonographic characterization of the dermo-epidermal complex (DEC) and of the subcutaneous (SUBC) tissue, assessing the feasibility of a related mapping, in upper limb secondary lymphedema.

METHODS

In this retrospective study 287 patients affected by monolateral upper limb post-mastectomy lymphedema (M5/F282; mean age 64±4.24) were enrolled and scanned by ultrasound, considering the healthy contralateral limb as control. In order to standardize the assessment, the limb was divided in sectors: 4 anterior, 4 posterior below the elbow, 4 anterior and 4 posterior above the elbow, plus the hand. DEC and SUBC regions B-mode appearance were reported, both in the healthy and in the pathological arms. DEC thickness was measured and compared among the same sectors of the healthy and pathological limbs.

RESULTS

DEC and SUBC sonographic appearance was differentiated in fluid and sclerotic. DEC included a third category characterized by differentiation loss. The different sectors showed significantly different lymphatic involvement in the affected limb. In the comparison with the contralateral unaffected segments a significantly thicker DEC was reported in the forearm affected by lymphedema (P<0.005), while no significant difference was reported at the arm level.

CONCLUSIONS

Traditional ultrasonography can provide a secondary upper limb lymphedema characterization with related mapping and useful data for a better lymphatic physiopathology understanding and for a properly addressed therapeutic protocol.

Sentinel Lymph Node Characterization with a Dual-Targeted Molecular Ultrasound Contrast Agent

PURPOSE

The purpose of this study was to assess the performance of molecular ultrasound with dual-targeted microbubbles to detect metastatic disease in the sentinel lymph nodes (SLNs) in swine model of naturally occurring melanoma. The SLN is the first lymph node in the lymphatic chain draining primary tumor, and early detection of metastatic SLN involvement is critical in the appropriate management of melanoma.

PROCEDURE

Nine Sinclair swine (weight 3-7 kg; Sinclair BioResources, Columbia, MO, USA) with naturally occurring melanoma were examined. Siemens S3000 scanner with a 9L4 probe was used for imaging (Siemens Healthineers, Mountain View, CA). Dual-targeted contrast agent was created using Targestar SA microbubbles (Targeson, San Diego, CA, USA) labeled with α_νβ₃-integrin and P-selectin antibodies. Targestar SA microbubbles labeled with IgG-labeled were used as control. First, peritumoral injection of Sonazoid contrast agent (GE Healthcare, Oslo, Norway) was performed to detect SLNs. After that, dual-targeted and IGG control Targestar SA microbubbles were injected intravenously with a 30-min interval between injections. Labeled Targestar SA microbubbles were allowed to circulate for 4 min to enable binding. After that, two sets of image clips were acquired several seconds before and after a high-power destruction sequence. The mean intensity difference pre- to post-bubble destruction within the region of interest placed over SLN was calculated as a relative measure of targeted microbubble contrast agent retention. This process was repeated for non-SLNs as controls. All lymph nodes evaluated on imaging were surgically removed and histologically examined for presence of metastatic involvement.

RESULTS

A total of 43 lymph nodes (25 SLNs and 18 non-SLNs) were included in the analysis with 18 SLNs demonstrating metastatic involvement greater than 5 % on histology. All non-SLNs were benign. The mean intensity (± SD) of the dual-targeted microbubbles for metastatic SLNs was significantly higher than that of benign LNs (18.05 ± 19.11 vs. 3.30 ± 6.65 AU; p = 0.0008), while IgG-labeled control microbubbles demonstrated no difference in retained contrast intensity between metastatic and benign lymph nodes (0.39 ± 1.14 vs. 0.03 ± 0.24 AU; p = 0.14).

CONCLUSIONS

The results indicate that dual-targeted microbubbles labeled with P-selectin and α_νβ₃-integrin antibodies may aid in detecting metastatic involvement in SLNs of melanoma.

Subdermal Ultrasound Contrast Agent Injection for Sentinel Lymph Node Identification: An Analysis of Safety and Contrast Agent Dose in Healthy Volunteers

OBJECTIVES

Mapping of the lymphatic chain for identification of the sentinel lymph node (SLN) is an important aspect of predicting outcomes for patients with breast cancer, and it is usually performed as an intraoperative procedure using blue dye and/or radiopharmaceutical agents. Recently, the use of contrast-enhanced ultrasound (CEUS) has been proposed as an alternative imaging technique for this mapping. The objective of this study was to evaluate the use of subdermal administration of the ultrasound (US) contrast agent Sonazoid (GE Healthcare, Oslo, Norway) in terms of patient safety and to select the dose to be used for lymphatic applications in humans.

METHODS

This study was performed in 12 female volunteers who received bilateral subdermal injections of Sonazoid (1 or 2 mL dose) in the mid-upper outer quadrant of their breasts at 2 different time points. Contrast-enhanced US examinations were performed 0, 0.25, 0.5, 1, 2, 4, 6, and 24 hours after injection to identify SLNs.

RESULTS

Sentinel lymph nodes were identified within the first hour after injection as enhanced structures, and there was no significant difference by dose in the number of SLNs identified (P = .74). The volunteers only had minor adverse experiences (AEs) that resolved completely without intervention by study completion.

CONCLUSIONS

The subdermal use of Sonazoid in this study showed only minor local and nonsignificant AEs that were completely resolved without any intervention. Two different doses were compared with no significant differences observed between them. Hence, the lower dose studied (1 mL) was selected for use in future clinical studies.

Detection and Pathologic Evaluation of Sentinel Lymph Nodes in the VX2 Tumor Model Using a Novel Ultrasound/Near-Infrared Dual-Modality Contrast Agent

This study was conducted with the aim of developing a microbubble agent for near-infrared (NIR) fluorescence and ultrasound dual-modality contrast microbubbles applicable to imaging of sentinel lymph nodes in the VX2 rabbit tumor model. Specific ligands of phosphatidylserine (PS) and Cy7 NIR fluorescent dyes with long emission wavelengths (750-900 nm) were conjugated to the surface of ultrasound contrast microbubbles (MBs), termed Cy7 PS MBs. Ultrasound lymphography and NIR fluorescence imaging were performed using subcutaneous injection of Cy7 PS MBs to visualize the sentinel lymph node. Sentinel lymph node detection rates using the patent blue method, ultrasound lymphography and NIR fluorescence imaging were 95%, 79% and 95%, respectively, and sensitivity was 87%, 74% and 92%, respectively. With 2-D ultrasound, the diagnostic sensitivity for detection of sentinel lymph node metastases was 60% and the specificity was 74%, whereas Cy7 PS MB-enhanced ultrasound had a sensitivity of 80% and a specificity of 87%. The results indicate that dual-modality Cy7 PS MBs combined with ultrasound lymphography and NIR fluorescence may be useful in the detection of normal and metastasized sentinel lymph nodes.