Sentinel lymph node biopsy as the new standard of care in the surgical treatment for breast cancer

A two-center study of a combined nomogram based on mammography and MRI to predict ALN metastasis in breast cancer

OBJECTIVES

To develop and validate a predictive method for axillary lymph node (ALN) metastasis of breast cancer by using radiomics based on mammography and MRI.

MATERIALS AND METHODS

A retrospective analysis of 492 women from center 1 (The affiliated Hospital of Qingdao University) and center 2 (Yantai Yuhuangding Hospital) with primary breast cancer from August 2013 to May 2021 was carried out. The radscore was calculated using the features screened based on preoperative mammography and MRI from the training cohort of Center 1 (n = 231), then tested in the validation cohort (n = 99), an internal test cohort (n = 90) from Center 1, and an external test cohort (n = 72) from Center 2. Univariate and multivariate analyses were used to screen for the clinical and radiological characteristics most associated with ALN metastasis. A combined nomogram was established in combination with radscore that predicted the clinicopathological and radiological characteristics. Calibration curves were used to test the effectiveness of the combined nomogram. The receiver operating characteristic (ROC) curve was used to evaluate the performance of the combined nomogram and then compare with the clinical and radiomic models. The decision curve analysis (DCA) value was used to evaluate the combined nomogram for clinical applications.

RESULTS

The constructed combined nomogram incorporating the radscore and MRI-reported ALN metastasis status exhibited good calibration and outperformed the radiomics signatures in predicting ALN metastasis (area under the curve [AUC]: 0.886 vs. 0.846 in the training cohort; 0.826 vs. 0.762 in the validation cohort; 0.925 vs. 0.899 in the internal test cohort; and 0.902 vs. 0.793 in the external test cohort). The combination nomogram achieved a higher AUC in the training cohort (0.886 vs. 0.786) and the internal test cohort (0.925 vs. 0.780) and similar AUCs in the validation (0.826 vs. 0.811) and external test (0.902 vs. 0.837) cohorts than the clinical model.

CONCLUSION

A combined nomogram based on mammography and MRI can be used for preoperative prediction of ALN metastasis in primary breast cancer.

The Value of BMI for Breast Reconstructions with the SIEA Flaps: Predicting the Ideal Intercostal Plane for the End-to-End Microvascular Anastomosis and the Possibility of Utilizing the TDA as a Salvage Recipient Choice

BACKGROUND

The superficial inferior epigastric artery (SIEA) diameter and the matching degree between the donor and the recipient arteries in terms of diameter are key factors affecting the outcome of the procedure in breast reconstructions with the SIEA flaps. A diameter of the SIEA ≥ 1.5 mm and a matching degree ≥ 1:2 (50%) of the diameters of the donor and the recipient arteries are recognized standards for the SIEA and the internal mammary artery (IMA) to achieve an end-to-end anastomosis. However, further refinements of the population characteristics and the ideal microscopic anastomosis intercostal planes are currently lacking for the criteria.

METHODS

In this study, based on 20 sides of hemiabdomen with computed tomography angiography (CTA) data suggesting the presence of the SIEA, we analysed the diameters of the donor and the recipient arteries as well as their matching degrees. The correlations between the parameters above and body mass index (BMI) were assessed. Based on the lower bounds of the 95% confidence intervals of the matching degrees and the two critical nodes of 50% and 67%, we theoretically evaluated the possibility of an end-to-end anastomosis of the SIEA and the IMA at different levels of BMIs and intercostal spaces, and predicted the possible intraoperative management measures for the SIEA.

RESULTS

The SIEA diameter, the thoracodorsal artery (TDA) diameter, and the diameters of the IMA at the 2nd to the 5th intercostal levels were positively correlated with the BMI (p < 0.05). A value of BMI ≥ 24 kg/m² could indirectly reflect the application premise of the diameter of the SIEA ≥ 1.5 mm. The matching degrees of the SIEA with the TDA or the IMA at the 2nd to the 5th intercostal level were linearly and positively correlated with the BMI (p < 0.001). Based on the confidence interval analysis, we predicted different management techniques that might be needed intraoperatively for the SIEA at different BMI levels, when the SIEA and the IMA or the TDA were to be anastomosed in an end-to-end way.

CONCLUSION

For patients with preoperative CTA data suggesting the presence of the SIEA in the second-stage breast reconstructions, when a value of BMI ≥ 24 kg/m² is met, the SIEA and the IMA can theoretically achieve an end-to-end anastomosis at the 3rd to the 5th intercostal level, and when 24 kg/m²≤ BMI ≤ 25 kg/m², due to the large difference in diameters, the SIEA and the IMA at the 2nd intercostal level might need to adopt an end-to-side anastomosis or switch to the TDA recipient site. Based on this study's findings and aesthetic effect considerations, we think that the 3rd and the 4th intercostal planes are ideal choices for the end-to-end anastomosis. As a salvage recipient option, the TDA can theoretically achieve an end-to-end anastomosis with the SIEA at a value of BMI ≥ 24 g/m².

LEVEL OF EVIDENCE IV

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Bi-modal near-infrared fluorescence and ultrasound imaging via a transparent ultrasound transducer for sentinel lymph node localization

Sentinel lymph node biopsy with an indocyanine green-based near-infrared fluorescence imaging system avoids the shortcomings of using a radioisotope or a combination of a blue dye and a radioactive tracer. To improve surgical precision, recent research has provided a depth profile of the sentinel lymph node by fusing fluorescence and ultrasound imaging. Here, we present a combined near-infrared fluorescence and ultrasound imaging system based on a transparent ultrasound transducer. The transparent ultrasound transducer enables seamless coaxial alignment of the fluorescence and ultrasound beam paths, allowing bi-modal observation of a single region of interest. Further, we demonstrate that the sentinel lymph node of mice injected with indocyanine green can be successfully localized and dissected based on information from the bi-modal imaging system.

A photoacoustic finder fully integrated with a solid-state dye laser and transparent ultrasound transducer

The standard-of-care for evaluating lymph node status in breast cancers and melanoma metastasis is sentinel lymph node (SLN) assessment performed with a handheld gamma probe and radioisotopes. However, this method inevitably exposes patients and physicians to radiation, and the special facilities required limit its accessibility. Here, we demonstrate a non-ionizing, cost-effective, handheld photoacoustic finder (PAF) fully integrated with a solid-state dye laser and transparent ultrasound transducer (TUT). The solid-state dye laser handpiece is coaxially aligned with the spherically focused TUT. The integrated finder readily detected photoacoustic signals from a tube filled with methylene blue (MB) beneath a 22 mm thick layer of chicken tissue. In live animals, we also photoacoustically detected both SLNs injected with MB and subcutaneously injected melanomas. We believe that our radiation-free and inexpensive PAF can play a vital role in SLN assessment.

Superparamagnetic Iron Oxide Sentinel Node Tracer Injection: Effects on Breast MRI Quality

OBJECTIVE

To evaluate the MRI artifact rendered by the typical injection of a ferromagnetic tracer now being intermittently used for intraoperative sentinel node (SN) identification at our institution, and to explore its impact on postoperative imaging and management.

METHODS

This study was Institutional Review Board-approved and granted a waiver of consent. A database search tool was used to identify MRI exams performed on patients who had previously undergone breast-conserving surgery with use of a superparamagnetic iron oxide (SPIO) SN tracer between January 1, 2015, and May 1, 2020. MRI reports, images, and relevant demographic, oncologic, and surgical history were collected. The presence or absence of SPIO residue on breast MRI, as well as its impact on image quality, were extracted from the prospective reports.

RESULTS

A total of 21 MRI exams were identified in 16 patients who had undergone breast-conservation therapy for cancer with use of SPIO SN tracer. Mean time from particle injection to baseline postoperative MRI exam was 10.8 months. All reports (21/21) noted evidence of SPIO residue. Of these, 5/21 were assessed as non-diagnostic; the remainder were assessed as limited.

CONCLUSION

Radiologists should be aware of the use of superparamagnetic tracers for SN identification and the impact on the quality of future MRI examinations. Alternative injection approaches are being developed and sequence parameters adjusted to minimize artifact.

The clinical significance of metastatic breast carcinoma to intramammary lymph node

The incidence of involved intramammary lymph node (intra-MLN) with breast carcinoma (BC) is rare. Its clinical significance and impact on the clinical decision making is unclear. A total of 113 BC cases with at least one positive intra-MLN were collected from 11 academic institutions. The inclusion criteria were subsequent axillary lymph node dissection, and the availability of information on T-stage, size of node metastasis, extranodal extension status, biomarkers status, and clinical follow-up. Stage 4 cases and/or neo-adjuvant treated patients were excluded. AJCC TN-stage was calculated twice, with and without intra-MLN. Five-year overall survival (OS) and relapse (local and/or distant)-free survival (RFS) were calculated and correlated with the clinicopathologic variables. Excluding intra-MLN, TN-stage correlated with OS (P = .016) but not with RFS (P = .19). However, when intra-MLN was included, TN-stage correlated with both OS (P < .001) and RFS (P = .016). In the multivariate analysis, when intra-MLN was excluded, only radiation therapy (RT) correlated with RFS (HR = 0.19, 95% CI: 0.054-0.66, P = .009). However, when intra-MLN was included in the TN-stage both RT (HR = 0.13, 95% CI: 0.04-0.45, P = .001) and TN-stage 3 (HR = 8.92, 95% CI: 1.47-54, P = .017) correlated with RFS. Tumor multifocality was the only variable correlated with OS when the intra-MLN involvement was excluded. When intra-MLN was included, multifocality became insignificant but TN-stage 3 correlated with OS (HR = 8.59, 95% CI: 1.06-69.71, P = .044). Positive intra-MLN is an independent factor in predicting both RFS and OS.

Salvaging Breast Reconstruction: Profunda Artery Perforator Flaps Using Thoracodorsal Vessels

Background:

Over the years, the choice of recipient vessels for free flap autologous breast reconstruction has shifted from the thoracodorsal to the internal mammary vessels due to ease of flap inset and predictability of anatomy. However, thoracodorsal vessels are still great recipient vessels, and can be useful, especially in the previously failed or staged autologous breast reconstruction. In this study, we present our experience using thoracodorsal or serratus vessels for profunda artery perforator flaps.

Methods:

Of the 792 autologous free flap breast reconstruction performed, we identified 12 patients (21 flaps) who underwent reconstruction using thoracodorsal or serratus vessels from 2012 to 2017. Flap, patient characteristics, and demographic data and perioperative details were collected.

Results:

Twenty-one flaps were used to reconstruct 14 breasts in 12 patients. The mean age of patients was 49.6 years old (range, 42–54), the mean flap weight was 354.7 g (range, 170–540 g), the mean body mass index was 28 (range, 23.2–34.4), and the average operative time was 496.1 minutes (266–680). Majority of these patients underwent additional staged free flap reconstruction (following previous deep inferior epigastric perforator flaps) for severe breast contour defects (58%) and for failed previous breast reconstruction (42%). The anastomosis was performed using thoracodorsal (43%), serratus (43%), and profunda artery perforator side branch (14%) vessels.

Conclusion:

Determining appropriate flap and recipient vessels in a previously failed or staged breast reconstruction is very challenging. Thoracodorsal and serratus vessels are excellent recipient vessels in patients who already have exhausted internal mammary vessels for previous breast reconstruction.

Study on the Efficacy of Sentinel Lymph Node Identification by Radionuclide Method (Tc 99) Versus Combined Method (Radionuclide and Vital Stain) in the Staging of Breast Carcinoma

Introduction: Sentinel node biopsy is the gold standard for axillary assessment of patients with breast cancer without axillary metastases on clinical and radiological examination. Internationally accepted biopsy methods currently use a radioactive tracer (Te) or different variations of vital stain, or the combination of the two. Due to the high cost of technical and organizational difficulty related to the radioactive material, as well as the disadvantages of using the vital stain method, great effort is being made to find alternative solutions. The aim of this study was to determine the effectiveness of the exclusive use of vital stain versus the radioactive isotope, and the need to use the combined method. A second goal was the comparative analysis of the radioactive method and intraoperative assessment of suspicious (non-sentinel) lymph nodes.

Materials and methods: This article is based on a prospective nonrandomized study conducted on 69 patients with early breast cancer in whom the combined method was used (injection of radionuclide and methylene blue vital stain). The comparatively monitored parameters were the following: the total and mean number of excised sentinel lymph nodes, the number of metastatic ganglia revealed by the 2 methods, and the risk of understaging in case only one technique was used.

Results: We excised 153 sentinel nodes identified by the radioisotope method. Of these only 56 were stained with methylene blue (p <0.0001). We could also identify a significantly higher number of metastatic nodes with the aid of the radioactive method (p = 0.0049). Most importantly, a significant number of patients (57.14%) who would have been declared node-negative using vital staining could only be properly staged using the radionuclide or the combined method. On microscopic examination of 35 non-sentinel lymph nodes, we found 3 lymph nodes with metastases, and in 1 case the metastases were found only in the non-sentinel lymph node.

Conclusions: Given the risk of understaging, exclusive use of the vital stain method is not recommended, especially under the ASGO Z 00011 Protocol, since the more accurate determination of the number of metastatic sentinel lymph nodes in a patient influences the decision whether to perform lymphadenectomy or not. Using the combined method confers benefits only during the learning curve, in our database we found no stained nodes which were not radioactive. It is very important that the intraoperative stage uses the radioactive method and the intraoperative assessment of suspicious lymph nodes, because 35 non-sentinel lymph nodes were identified in our study, 3 of which had metastases, while in 1 case the metastases were in the non-sentinel lymph node.

The Nordic SentiMag trial: a comparison of super paramagnetic iron oxide (SPIO) nanoparticles versus Tc(99) and patent blue in the detection of sentinel node (SN) in patients with breast cancer and a meta-analysis of earlier studies

The aim of the study is to compare the efficacy of SPIO as a tracer in sentinel node biopsy (SNB) in breast cancer with Tc and patent blue in a multicentre prospective study and perform a meta-analysis of all published studies. It also aims to follow skin discoloration after SPIO injection and describe when and how it resolves. Totally 206 patients with early breast cancer were recruited. Tc and patent blue were administered in standard fashion. Patients were injected with SPIO (Sienna+) preoperatively. SNB was performed and detection rates were recorded for both methods. Skin discoloration was followed and documented postoperatively. Data extraction and subsequent meta-analysis of all previous studies were also performed. SN detection rates were similar between standard technique succeeded and SPIO both per patient (97.1 vs. 97.6 %, p = 0.76) as well as per node (91.3 vs. 93.3 %, p = 0.34), something which was not affected by the presence of malignancy. Concordance rates were also consistently high (98.0 % per patient and 95.9 % per node). Discoloring was present in 35.5 % of patients postoperatively, almost exclusively in breast conservation. It fades slowly and is still detectable in 8.6 % of patients after 15 months. Meta-analysis depicted similar detection rates (p = 0.71) and concordance rates (p = 0.82) per patient. However, it seems that SPIO is characterized by higher nodal retrieval (p < 0.001). SPIO is an effective method for the detection of SN in patients with breast cancer. It is comparable to the standard technique and seems to simplify logistics. Potential skin discoloration is something of consideration in patients planned for breast conservation.

Accurate and rapid novel genetic diagnosis for detection of sentinel lymph node metastasis in breast cancer patients

Background:

The transcription-reverse transcription concerted reaction (TRC) test is a novel molecular-based procedure, which can assess nodal metastasis accurately and quickly. We examined the usefulness of the TRC test with a double marker, cytokeratin 19 (CK19) and carcinoembryonic antigen (CEA) mRNA, to detect sentinel lymph nodes (SLN) metastasis in breast cancer patients.

Methods:

A total of 264 SLNs from 131 breast cancer patients were assigned to a training set (109 SLNs from 50 patients) and validation set (155 SLNs from 81 patients). Cytokeratin 19 and CEA mRNA were detected by TRC tests, and the sensitivity and specificity of the SLN metastasis between the TRC and histology cohorts were compared.

Results:

Mean copy numbers of CK19 and CEA by TRC tests were increased according to the metastatic size. In the training set, TRC test showed 100% sensitivity, specificity and concordance rates against the permanent histopathology test. In the validation set, sensitivity was 97.1%, specificity was 99.2% and the concordance rate was 99.4%.

Conclusion:

Our results showed that the detection of CK19 and CEA mRNA using the TRC test is, an accurate and rapid method for detection of SLN metastasis and can be applied as an intraoperative molecular diagnosis in breast cancer patients.

Fluorescence imaging and whole-body biodistribution of near-infrared-emitting quantum dots after subcutaneous injection for regional lymph node mapping in mice

PURPOSE

This study compares fluorescence imaging to mass spectroscopy (inductively coupled plasma-mass spectroscopy, ICP-MS) for detection of quantum dots (QDs) in sentinel lymph node (LN) mapping of breast cancer.

PROCEDURES

We study the accumulation of near-infrared-emitting QDs into regional LNs and their whole-body biodistribution in mice after subcutaneous injection, using in vivo fluorescence imaging and ex vivo elemental analysis by ICP-MS.

RESULTS

We show that the QD accumulation in regional LNs is detectable by fluorescence imaging as early as 5 min post-delivery. Their concentration reaches a maximum at 4 h then decreases over a 10-day observation period. These data are confirmed by ICP-MS. The QD uptake in other organs, assessed by ICP-MS, increases steadily over time; however, its overall level remains rather low.

CONCLUSIONS

Fluorescence imaging can be used as a non-invasive alternative to ICP-MS to follow the QD accumulation kinetics into regional LNs.

Technical limits of comparison of step-sectioning,immunohistochemistry and RT-PCR on breast cancer sentinel nodes: a study on methacarn-fixed tissue

The optimal pathological assessment of sentinel nodes (SLNs) in breast cancer is a matter of debate. Currently, multilevel histological evaluation and immunohistochemistry (IHC) are recommended, but alternative RT-PCR procedures have been developed. To assess the reliability of these different procedures, we devised a step-sectioning protocol at 100 micron-intervals of 74 SLNs using methacarn fixation. mRNA was extracted from sections collected from levels 4 to 5. Mammaglobin, CEA and CK19 were used for RT-PCR. mRNA extraction was successful in 69 SLNs. Of these, 7 showed macrometastases (>2mm), 2 showed micrometastases (<2 mm) and 7 showed isolated tumour cells (ITC) by IHC. RT-PCR was positive for the three markers in 6 of 7 macrometastases and in 1 of 2 micrometastases. In the 2 RT-PCR negative cases, metastases were detected only on sections distant from those analysed by RT-PCR. CEA and/or CK19 were positive by RT-PCR in 3 of 7 ITC and in 23 morphologically negative SLNs. In conclusion, the main goal of our study was to show that the use of alternate sections of the same sample for different procedures is the key reason for the discrepancies between molecular and morphological analyses of SLN. We believe that only prospective studies with quantitative mRNA analysis of specific metastatic markers on the whole lymph node can elucidate the utility of molecular assessments of SLN.

Sentinel lymph node biopsy in the pediatric population

BACKGROUND

Sentinel lymph node biopsy (SLNB) has only been recently used for childhood neoplasms.

METHODS

We reviewed all patients younger than 19 years who underwent SLNB for 5 years.

RESULTS

Twenty patients were identified (11 male, 9 female). Sentinel lymph node biopsy was performed for 10 sarcomas (5 synovial, 3 rhabdomyosarcoma, 1 epitheliod, 1 other); 9 skin neoplasms (4 melanomas, 3 Spitz nevi, 2 melanocytomas); and 1 acinic cell carcinoma. All patients underwent Technetium 99m sulfur microcolloid injection and 4-quadrant subdermal injection with Lymphazurin 1% (Autosuture, Norwalk, Conn). Six patients required either sedation for lymphoscintigraphy. Intraoperative gamma probe was used. Primary lesions were found in lower extremity (n = 8), upper extremity (n = 6), trunk (n = 3), and head and neck (n = 3). The lymphatic basins were inguinal (n = 8), axilla (n = 8), neck (n = 3), and both inguinal and axilla (n = 1). At least one lymph node was identified in each procedure. Of 20 patients, 5 (25%) had metastatic disease (4 skin neoplasms and 1 sarcoma). There were no complications in our series, and all patients are alive with no recurrence at an average follow-up of 2.2 years.

CONCLUSIONS

Sentinel lymph node biopsy allows for an accurate biopsy in children. However, some younger patients may require sedation, and it may be more challenging to isolate the sentinel node.

Intra-operative rapid diagnostic method based on CK19 mRNA expression for the detection of lymph node metastases in breast cancer

Staging by sentinel node (SN) biopsy is the standard procedure for clinically node-negative breast cancer patients. Intra-operative analysis of the SN allows immediate axillary lymph node (ALN) dissection in SN positive patients, but a quick, reliable and reproducible method is lacking. We tested the suitability of a quantitative cytokeratin 19 (CK19) mRNA one step nucleic acid amplification (OSNA#) technique (OSNA-CK19) for intra-operative SN analysis. OSNA-CK19 involves a short manual sample preparation step and subsequent fully automated amplification of CK19 mRNA based on reverse transcription loop-mediated isothermal amplification, with results available within 30–40 min. OSNA-CK19 was compared to histological staining (Hematoxylin&Eosin and CAM5.2 and CK19 immunostaining) of 346 frozen ALNs from 32 breast cancer patients, using half of the lymph node for each method. 267 samples were negative and 61 positive by both methods. Three samples were histology positive and OSNA-CK19 negative. Fifteen samples were histology negative and OSNA-CK19 positive, 11 of which had copy numbers close to the cut-off level of OSNA-CK19. Seven of these 15 samples were RT-PCR positive for epithelial markers and/or showed CK19 protein expression by Western blot suggesting the presence of tumor deposits in the lymph node part investigated by OSNA-CK19. Concordance with histology was 94.8%, and 96.8% after exclusion of the latter 7 discordant cases. Sensitivity was 95.3% and specificity was 94.7% before and 97.1% after discordant case investigation. Our results indicate that OSNA-CK19 can potentially be useful in an intra-operative clinical setting to detect SN tumor involvement in breast cancer patients.

Multimodal nanoprobes for radionuclide and five-color near-infrared optical lymphatic imaging

Current contrast agents generally have one function and can only be imaged in monochrome; therefore, the majority of imaging methods can only impart uniparametric information. A single nanoparticle has the potential to be loaded with multiple payloads. Such multimodality probes have the ability to be imaged by more than one imaging technique, which could compensate for the weakness or even combine the advantages of each individual modality. Furthermore, optical imaging using different optical probes enables us to achieve multicolor in vivo imaging, wherein multiple parameters can be read from a single image. To allow differentiation of multiple optical signals in vivo, each probe should have a close but different near-infrared emission. To this end, we synthesized nanoprobes with multimodal and multicolor potential, which employed a polyamidoamine dendrimer platform linked to both radionuclides and optical probes, permitting dual-modality scintigraphic and five-color near-infrared optical lymphatic imaging using a multiple-excitation spectrally resolved fluorescence imaging technique.