Examination Of Sentinel Lymph Nodes Research Articles

Feasibility of intraoperative pathologic examination for sentinel lymph nodes during sentinel node navigation surgery in early gastric cancer: results of pathologic protocol for SENORITA trial.

During sentinel node navigation surgery in patients with gastric cancer, intraoperative pathologic examination of sentinel nodes is crucial in determining the extent of surgery. In this study, we evaluated the feasibility and accuracy of intraoperative pathologic protocols using data from a prospective, multicenter, randomized trial. A retrospective analysis was conducted using data from the SEntinel Node ORIented Tailored Approach trials from 2013 to 2016. All sentinel lymph nodes were evaluated during surgery with hematoxylin-eosin (HE) staining using a representative section at the largest plane for lymph nodes. For permanent histologic evaluation, sentinel basin nodes were stained with HE and cytokeratin immunohistochemistry in formalin-fixed, paraffin-embedded (FFPE) sections and examined with HE for three deeper-step sections at 200-μm intervals. The failure rate of identification by frozen section and the metastasis rate in non-sentinel basins were investigated. Of the 237 patients who underwent sentinel node basin dissection, 30 had lymph node metastases on permanent pathology. Thirteen patients had macrometastasis confirmed in frozen sections as well as FFPE sections (failure rate: 0%). Patients with negative sentinel nodes in frozen sections but micrometastasis in FFPE sections had no lymph node recurrence during the follow-up period (0%, 0/6). However, in cases with tumor-positive nodes in frozen sections, metastases in non-sentinel basins were detected in the paraffin blocks (8.3%, 2/24). The single-section HE staining method is sufficient for detecting macrometastasis via intraoperative pathological examination. If a negative frozen-section result is confirmed, sentinel basin dissection can be performed safely. Otherwise, standard surgery is required.

Analysis of false reasons based on the artificial intelligence RRCART model to identify frozen sections of lymph nodes in breast cancer.

Breast cancer is the most common malignant tumor in the world. Intraoperative frozen section of sentinel lymph nodes is an important basis for determining whether axillary lymph node dissection is required for breast cancer surgery. We propose an RRCART model based on a deep-learning network to identify metastases in 2362 frozen sections and count the wrongly identified sections and the associated reasons. The purpose is to summarize the factors that affect the accuracy of the artificial intelligence model and propose corresponding solutions. We took the pathological diagnosis of senior pathologists as the gold standard and identified errors. The pathologists and artificial intelligence engineers jointly read the images and heatmaps to determine the locations of the identified errors on sections, and the pathologists found the reasons (false reasons) for the errors. Through NVivo 12 Plus, qualitative analysis of word frequency analysis and nodal analysis was performed on the error reasons, and the top-down error reason framework of "artificial intelligence RRCART model to identify frozen sections of breast cancer lymph nodes" was constructed based on the importance of false reasons. There were 101 incorrectly identified sections in 2362 slides, including 42 false negatives and 59 false positives. Through NVivo 12 Plus software, the error causes were node-coded, and finally, 2 parent nodes (high-frequency error, low-frequency error) and 5 child nodes (section quality, normal lymph node structure, secondary reaction of lymph nodes, micrometastasis, and special growth pattern of tumor) were obtained; among them, the error of highest frequency was that caused by normal lymph node structure, with a total of 45 cases (44.55%), followed by micrometastasis, which occurred in 30 cases (29.70%). The causes of identification errors in examination of sentinel lymph node frozen sections by artificial intelligence are, in descending order of influence, normal lymph node structure, micrometastases, section quality, special tumor growth patterns and secondary lymph node reactions. In this study, by constructing an artificial intelligence model to identify the error causes of frozen sections of lymph nodes in breast cancer and by analyzing the model in detail, we found that poor quality of slices was the preproblem of many identification errors, which can lead to other errors, such as unclear recognition of lymph node structure by computer. Therefore, we believe that the process of artificial intelligence pathological diagnosis should be optimized, and the quality control of the pathological sections included in the artificial intelligence reading should be carried out first to exclude the influence of poor section quality on the computer model. For cases of micrometastasis, we suggest that by differentiating slices into high- and low-confidence groups, low-confidence micrometastatic slices can be separated for manual identification. The normal lymph node structure can be improved by adding samples and training the model in a targeted manner.

A prospective comparison of a modified miniaturised hand-held epifluorescence microscope and touch imprint cytology for evaluation of axillary sentinel lymph nodes intraoperatively in breast cancer patients.

The management of axillary lymph nodes in early-stage breast cancer patients has changed considerably, with the primary focus shifting from the examination of sentinel lymph nodes (SLNs) to toward the detection of all macro-metastases. However, current methods, such as touch imprint cytology (TIC) and frozen sections, are inadequate for clinical needs. To address this issue, we proposed a novel miniaturised epifluorescence widefield microscope (MEW-M) to assess SLN status intraoperatively for improved diagnostic efficiency. A prospective, side-by-side comparison of intraoperative SLN evaluation between MEW-M and TIC was performed. A total of 73 patients with 319 SLNs consecutive enrolled in this study. MEW-M showed significantly superior image quality compared to TIC (median score 3.1 vs 2.1, p < 0.0001) and had a shorter time to issue results (10.3 vs 19.4 min, p < 0.0001). Likelihood ratio analysis illustrated that the positive likelihood ratio value of MEW-M compared with TIC was infinitely great vs 52.37 (95% CI, 21.96-124.90) in model 1 (classifying results into negative/positive), infinitely great vs 52.37 (95% CI, 21.96-124.90) in model 2 (classifying results into macro-metastasis/others, and TIC results followed the same classification as model 1), respectively. Similarly, the negative likelihood ratio values of MEW-M compared with TIC were 0.055 (95% CI, 0.018-0.160) and 0.074 (95% CI, 0.029-0.190) in model 1; and 0.019 (95% CI, 0.003-0.130) vs 0.020 (95% CI, 0.003-0.140) in model 2, respectively. MEW-M is a promising technique that can be utilised to provide a rapid and accurate intraoperative assessment of SLN in a clinical setting to help improve decision-making in axillary surgery.

Misleading images of ductal carcinoma in situ: 4 lymph nodes with metastasis

Since sentinel lymph node examination became routine, findings of benign ectopic breast tissue in lymph nodes have increased. We report images of ductal carcinoma in situ (DCIS) in four lymph nodes in a 76-year-old woman with bilateral breast carcinoma. The right lumpectomy showed intermixed invasive lobular and ductal carcinoma, plus DCIS. 19 nodes were isolated in the axillary lymphadenectomy, 4 of which displayed solid and cribriform DCIS. Myosin and p63 immunohistochemical techniques were positive, suggesting an erroneous diagnosis of “metastatic DCIS”. A further three cases of DCIS in lymph nodes have been previously reported, all with a distinct layer of myoepithelial cells with actin, myosin or p63. Biologically, these images of DCIS in lymph nodes are not credible and three major hypotheses have been proposed to explain these findings: Iatrogenic Mechanical Transport, Revertant DCIS, and primary DCIS of lymph nodes. We consider the first one the most plausible explanation. Our case is unique as several, rare findings are simultaneously observed. More new cases, together with additional immunohistochemical techniques and molecular testing on previous cases, are needed to find a definitive explanation of this histologic finding.

Application of Raman spectroscopy in breast cancer surgery

The incidence of breast cancer is increasing worldwide. As cancer screening has become more widespread, the rate of early breast cancer detection has increased and treatment methods have changed. Partial mastectomy is performed more often than total mastectomy for the surgical treatment of early breast cancer, and sentinel lymph node biopsy plays an important role. A high level of accuracy is necessary for the intraoperative examination of surgical margins and sentinel lymph nodes to identify malignancies. Therefore, several examination techniques, including Raman spectroscopy, that replace or supplement the currently used frozen-section methods are being studied. Raman spectroscopy has the ability to diagnose cancer in normal tissue by providing in real time a chemical fingerprint that can be used to differentiate between cells and tissues. Numerous studies have investigated the utilization of Raman spectroscopy to identify cancer in the margins of resected tissues and sentinel lymph nodes during breast cancer surgery, showing the potential of this technique for clinical applications. This article introduces and reviews the research on Raman spectroscopy for breast cancer surgery.

The role and place of transanal endoscopic resections in rectal cancer

The aim of the work is to improve the algorithm of intraoperative diagnosis of rectal cancer metastasis in order to optimize surgical intervention and reduce the number of intraoperative and postoperative complications. Materials and methods. 184 operated patients with rectal cancer (RC) were divided into 2 groups: group 1 – patients with stage I RC (T1–2N0M0), and group 2 – stage II RC (T3N0M0), who underwent intraoperative detection and examination of sentinel lymph nodes. The volume and surgical approach depended on the stage and the presence of metastases (MTS). The average period of postoperative observation was 12–60 months, taking into account early (purulent-septic complications, bleeding, intestinal perforation) and late (recurrent rectal cancer) complications. Results. The patients of group 1 had no MTS lesions of the sentinel lymph nodes, the surgical intervention was limited to transanal microsurgery due to this fact. Among the complications were the following: bleeding – 2.2 %; intraoperative perforation of the intestinal wall – 5.6 %. No purulent-septic cases, no recurrences of rectal cancer were detected. In group 2, 36 (38.3 %) out of 94 patients had MTS detected intraoperatively in the sentinel lymph nodes which required a low anterior rectal resection with total mesorectumectomy. Among the complications was bleeding – 6.3 %. No intraoperative perforations of the intestinal wall and no purulent-septic complications were detected. Recurrence of rectal cancer was detected in 12 (12.8 %) patients. Conclusions. Performing transanal endoscopic resections in patients with stage I RC and especially stage II RC is possible only under the conditions of mandatory intraoperative staining and urgent histological examination of the sentinel lymph nodes. The extent of the surgical intervention is determined on the operating table based on urgent histological examination results. When MTS lesions of the mesorectal sentinel lymph nodes are detected, the operation should be continued with mandatory mesorectumectomy.

Reducing workload in malignant melanoma sentinel node examination: a national study of pathology reports from 507 melanoma patients

AimsEven though extensive melanoma sentinel node (SN) pathology protocols increase metastasis detection, there is a need for balancing high detection rates with reasonable workload. A newly tested Danish protocol recommended...

Lymph Node and Distant Metastases in Phyllodes Tumor of the Breast.

A 54-year-old woman who incidentally noticed a "knot" in her left breast subsequently underwent excisional biopsy which yielded a diagnosis of malignant neoplasm with sarcomatous features. Given the broad differential diagnosis and imaging findings, the patient underwent bilateral mastectomy and intraoperative sentinel lymph node assessment. An 8.5 cm tumor that was further classified as a malignant phyllodes tumor was identified in the left breast, while the frozen section interpretation came back as positive for metastatic disease which resulted in left axillary lymphadenectomy. Two months later the patient progressed to distant metastatic disease and unfortunately passed away within 6 months after her initial diagnosis. Lymph node metastasis in phyllodes tumor is an exceptionally rare event for which patients usually do not undergo intraoperative sentinel lymph node examination; however high clinical suspicion of metastatic disease would be evidence for further investigation.

ASO Author Reflections: Standardizing Pathology Examination of Sentinel Lymph Nodes in Invasive Lobular Carcinoma: Less Is More

ASO Author Reflections: Standardizing Pathology Examination of Sentinel Lymph Nodes in Invasive Lobular Carcinoma: Less Is More

New trends in the surgical treatment of axilla in breast cancer

Oncosurgical treatment of breast tumors involves the removal of metastatic axillary lymph nodes. In the last 30 years, the diagnosis and treatment of axillary lymph nodes have also undergone significant changes. The introduction of sentinel lymph node biopsy in 1993 made axillary block dissection with high morbidity safely omitted in a significant proportion of patients, and similarly, the staging of breast tumors and thus oncology and complex treatment became significantly more accurate. Shortly after the introduction of sentinel lymph node biopsy, intraoperative examination of sentinel lymph nodes (e.g. imprint cytology) also appeared, which significantly reduced the number of surgeries performed in the two sessions, thereby significantly reducing patient burden and surgical costs. The results of our study indicate that axillary block dissection is required in the treatment of axilla in an ever-decreasing group of patients and this proportion will decrease further in the future, with the increasing use of alternative axillary radiotherapy. The imprint cytological examination of sentinel lymph nodes taking into account current guidelines, no longer provides demonstrable benefits and its routine use is not justified. According to the latest international recommendations, intraoperative examination of the sentinel lymph node may be indicated in connection with mastectomy (when postoperative radiotherapy is not planned) and after neoadjuvant treatment. Our results suggest that the detection of suspected lymph nodes during preoperative axillary ultrasound may predict the stage of the disease. Based on our research results confirm that in patients receiving neoadjuvant therapy, in addition to the preoperative size of the tumour (≤20 mm,P= 0.002), the preoperative size of the lymph node (≤15 mm,P= 0.04) may also be used to predict that the stage of the disease is N0-1.

Improved diagnostics of “concealed” metastases in patients with сТ1–2N0М0 oral squamous cell carcinoma

Introduction. Oral squamous cell carcinoma is associated with a high risk of regional metastasis even in early stages (T1–2N0M0). Morphological examination reveals concealed metastases in 20 % of removed clinically unaffected lymph nodes.Objective – to evaluate the effectiveness of flow cytometry for detection of concealed metastases in sentinel lymph nodes as an indication for cervical lymph node dissection in patients with stage сT1–2N0M0 oral squamous cell carcinoma.Materials and methods. This study included 27 patients, including 13 patients (48.1 %) with stage T1N0M0 cancer and 14 patients with stage T2N0M0 cancer (51.9 %). At the first stage, all participants underwent primary tumor removal and cervical lymph node dissection with sentinel lymph node examination. After mobilization, half of these lymph nodes was used for routine morphological examination followed by immunohistochemical examination, while the second half of them was analyzed using flow cytometry. Then we compared the results obtained.Results. We examined 46 removed sentinel lymph nodes from 27 patients. Conventional histological examination revealed 4 concealed metastases (8.7 %). Polymerase chain reaction allowed us to detect another 16 metastases (37.8 %). Levels I, II, and III lymph nodes were most frequently affected. Flow cytometry demonstrated that 20 % of patients with a &lt;4 mm invasion had concealed metastases, whereas patients with a 4 to 8 mm invasion had concealed metastases in 60 % of cases. Median follow-up time was 20.4 ± 11.7 months (range: 2.2 to 42.5 months; median 19.5 months). All participants were alive during this time. Seventeen out of 27 patients with stage T1–2N0M0 disease (63 %) were found to have concealed metastases, while the remaining ten patients (37 %) had no metastasis. One patient with stage T1N0M0 oral floor squamous cell carcinoma underwent the removal of the primary tumor and sentinel lymph node. Morphological examination and flow cytometry showed no metastatic lesions. After 14.8 months, the patient developed ipsilateral regional CN3 metastasis. The three-year progression-free survival rate was 94.7 ± 5.1 %.Conclusion. Highly sensible and rapid flow cytometry can become the method of choice in the diagnosis of metastases and deciding on cervical lymph node dissection in patients with cN0 disease. The study is still ongoing.

A Comprehensive Grading System for a Magnetic Sentinel Lymph Node Biopsy Procedure in Head and Neck Cancer Patients.

Simple SummaryWith 30% of clinically negative early-stage oral cancer patients harboring occult metastasis, an accurate staging of metastatic lymph nodes (LN) is of utmost importance for treatment planning. A magnetic sentinel lymph node biopsy (SLNB) procedure is offered as an alternative to conventional SLNB in oral oncology, however, a grading system is missing. A proper grading system is preferred to connect the different components of the magnetic SLNB: preoperative imaging, intraoperative detection, and histopathological examination of sentinel lymph nodes (SLNs). This study aims to provide a first grading system based on the distribution of a magnetic tracer, by means of preoperative magnetic resonance imaging (MRI), intraoperative estimation of iron content, and histopathological assessment of resected nodes. Pre- and post-operative MRI and harvested SLNs of eight tongue cancer patients with successful magnetic SLNB procedure were used for analyses.A magnetic sentinel lymph node biopsy ((SLN)B) procedure has recently been shown feasible in oral cancer patients. However, a grading system is absent for proper identification and classification, and thus for clinical reporting. Based on data from eight complete magnetic SLNB procedures, we propose a provisional grading system. This grading system includes: (1) a qualitative five-point grading scale for MRI evaluation to describe iron uptake by LNs; (2) an ex vivo count of resected SLN with a magnetic probe to quantify iron amount; and (3) a qualitative five-point grading scale for histopathologic examination of excised magnetic SLNs. Most SLNs with iron uptake were identified and detected in level II. In this level, most variance in grading was seen for MRI and histopathology; MRI and medullar sinus were especially highly graded, and cortical sinus was mainly low graded. On average 82 ± 58 µg iron accumulated in harvested SLNs, and there were no significant differences in injected tracer dose (22.4 mg or 11.2 mg iron). In conclusion, a first step was taken in defining a comprehensive grading system to gain more insight into the lymphatic draining system during a magnetic SLNB procedure.

Application of fluorescent immunocytochemistry in intraoperative diagnostics of metastases in sentinel lymph nodes in early breast cancer.

The aim of the study was to show the possibilities of fluorescent immunocytochemistry in urgent intraoperative examination of sentinel lymph nodes in patients with early breast cancer. The authors analyzed the data on the state of the lymph nodes in 94 patients with early breast cancer who had been operated on since December 2016 to January 2018 in the Department of reconstructive plastic surgery of the breast and skin of the P.A. Herzen Moscow Oncological Institute. As a result of the use of the «Tekhnefit99ᵐTc» radiopharmaceutical during the operation, sentinel lymph nodes were isolated, the state of which was assessed by the method of urgent intraoperative cytology. In difficult-to-diagnose cases, fluorescent immunocytochemistry was used, which made it possible to avoid hypo- and overdiagnosis in 30 patients with early breast cancer. The sensitivity of the urgent cytological method for examining the sentinel lymph nodes smears was 83.3%, the specificity - 100%, the efficiency -83%, the predictive value of a positive result - 83.3%, and the predictive value of a negative result - 100%. Thus, the diagnostic accuracy of urgent cytological examination of the sentinel lymph node was 94%.

Intraoperative Sentinel Lymph Node Imprint Cytology Diagnosis in Breast Cancer Patients by General Surgical Pathologists: A Single-Institution Experience of 4327 Cases.

Context:Sentinel lymph node (SLN) biopsy is the standard of care for breast cancer (BC) patient staging. The axillary node status can be evaluated by frozen section (FS) or imprint cytology (IC). Despite the major disadvantages of tissue loss and freezing artifact in FS, many pathologists consider SLN IC a more difficult task requiring special expertise and prefer FS to IC.Aims:To conduct a large cohort study to evaluate the results of intraoperative SLN IC, compare them with those of FS and permanent section (PS), and determine the best method for general pathologists.Settings and Design:A very large cohort study with many pathologists engaged was designed and the diagnostic results were compared.Materials and Methods:With 12 pathologists engaged, we conducted the largest patient cohort study of SLN IC to date, including 4,327 consecutive BC patients undergoing SLN biopsy during the past 15 years. The touch imprints were stained using three different methods and evaluated. The PS was used as the gold standard for evaluation.Statistical Analysis:The false positivity, false negativity, accuracy, sensitivity, and specificity of the IC and FS for each pathologist were evaluated and compared.Results:Our results showed an overall sensitivity of 82.7%, specificity of 99.3%, and an accuracy rate of 95.9% for SLN IC, which were comparable to those of FS. The accuracy rate did not correlate with the length of working experience and the staining method.Conclusions:Intraoperative hematoxylin and eosin (H&E)-stained IC preparation was found to be the best SLN examination method for general pathologists.

Utility of Intraoperative Frozen Section of the Inguinofemoral Sentinel Lymph Node in Vulvar Cancer: A Retrospective Cohort

Objective: Sentinel lymph node dissection (SLND) spares most patients diagnosed with clinically early-stage vulvar cancer from undergoing complete inguinofemoral lymphadenectomy (IFLND). We sought to evaluate the intraoperative examination of frozen sentinel lymph node (SLN) sections to assess the need for IFLND. Methods: We identified patients with vulvar cancer treated at a tertiary referral center between January 2006 and December 2019 who either underwent SLND or met the eligibility criteria to receive SLND. All patients were restaged according to the International Federation of Gynaecology and Obstetrics (FIGO) 2009 guidelines. The records of each patient were reviewed for disease characteristics, follow-up status, patient demographics, SLN eligibility, and surgical and pathologic variables. Results: Of 142 eligible patients, 76 underwent SLND (53.5%) for a total of 118 groins assessed. We found no statistically significant differences in characteristics between the cohorts that received or lacked SLN examination. The SLN was detected in 90.8% (95% Confidence Interval (CI): 81.9%–96.2%) of patients. SLNs of 52 patients were sent for frozen section, and the results were used to direct further surgical intervention. The results of the frozen section pathology and the final pathology report exhibited a high degree of correlation per patient (100%) and per groin (98.7%). The 1 incorrect groin was negative on frozen but positive on final pathology and therefore no patients received an incorrect complete groin dissection. We observed no statistically significant differences in recurrence-free survival or overall survival rates between those patients who received or did not receive SLND. Conclusions: The use of intraoperative frozen section is appropriate for assessing node status at time of initial surgery. The use of this method decreases the incidence of reoperation by identifying those patients who warrant immediate IFLND.

The accuracy of intraoperative frozen section examination of sentinel lymph nodes in squamous cell cancer of the vulva

ObjectiveTo assess the diagnostic accuracy of intraoperative pathologic examination of sentinel lymph nodes (SLNs) and patient outcomes in vulva cancer. MethodsThis retrospective study included patients with unifocal, <4 cm, invasive vulvar squamous cell carcinoma and clinically negative groin nodes treated with SLN biopsy from January 2008–March 2020. Intraoperative SLN frozen section and final pathology were compared. If the SLN was negative, inguinal femoral lymphadenectomy (IFLD) was omitted. Recurrence location and groin recurrence free survival (RFS) were assessed. ResultsThe SLN cohort included 173 patients, with 258 groins. On frozen section, there were 36/258 positive and 222 negative groins. On final pathology, there were 39/258 positive: 31 macrometastases, 6 micrometastases, 2 isolated tumor cells (ITCs) and 219 negative groins. The sensitivity, specificity, PPV and NPV for intraoperative detection of metastatic disease, was 89.7% and 99.5%, 97.2% and 98.2%, respectively. There was 1 false positive and 4 false negative frozen section results where final pathology revealed 2 ITCs, 1 micrometastasis and 1 macrometastasis. Based on intraoperative results, thirty patients (17.3%) underwent immediate IFLD.Median follow up was 38.0 (1–137.8) months. The 3-year groin RFS was 91.6% (95% CI 86.2–97.4%) for negative SLNs and 64.6% (95% CI 46.5–89.7%) for positive SLNs on frozen section. Similarly, the 3-year groin RFS was 91.7% (95% CI 86.3–97.4%) for negative, 58.4% (95% CI 38.5–87.7%) for macrometastases and 100% for micrometastases/ITCs on final pathology. ConclusionsIntraoperative assessment of SLNs is accurate to determine need for IFLD and does not compromise patient outcomes in vulvar cancer.

Rationale for extent of operation choice in rectal cancer

Introduction. Colorectal cancer (CRC) remains relevant occupying one of the leading places in morbidity and mortality among oncological diseases. It reaches 13.5% in the structure of tumor diseases tending to increase.&#x0D; The aim of the work to improve the choice of surgical treatment management and reduce the number of intraoperative and postoperative complications in rectal cancer patients.&#x0D; Materials and methods. 184 operated patients with rectal cancer (RC) were divided into 2 groups: 1 group (patients with stage I RC (T1-2N0M0) and 2 group (stage II RC (T3N0M0)) who were carried out intraoperative detection and examination of sentinel lymph nodes. The volume and surgical approach depended on the stage and the presence of metastases (MTS). The average period of postoperative observation was 12–60 months, taking into account early (purulent-septic complications, bleeding, intestinal perforation) and distant (recurrence of rectal cancer) complications.&#x0D; Results. The patients of the 1 group had no MTS lesions of sentinel lymph nodes, due to this fact the surgical intervention was limited to transanal microsurgery. Among the complications were the following: bleeding – 2.2%; intraoperative perforation of the intestinal wall – 5.6%. No purulent-septic cases, no recurrences of rectal cancer were detected. In group 2, of 94 patients, 36 (38.3%) had MTS detected intraoperatively in sentinel lymph nodes which required a low anterior rectal resection with total mesorectomectomy. Among the complications was bleeding – 6.3%. No intraoperative perforations of the intestinal wall and no purulent-septic complications were detected. Recurrence of rectal cancer was detected in 12 (13.8%) patients.&#x0D; Conclusions. Performing transanal endoscopic resections in patients with RC I and especially stage II is possible only under the conditions of mandatory intraoperative staining and emergency histological examination of "sentinel" lymph nodes. The extent of surgical intervention is determined on the operating table based on the results of an emergency histological examination. When MTS lesions of the mesorectal "sentinel lymph nodes" are detected, the operation should be continued with mandatory mesorectomectomy.

Evaluation of the Radiation Dose of an Embryo/Fetus during Lymphoscintigraphy (Sentinel Lymph Node Mapping) in Pregnant Patients with Breast Cancer

Purpose: To develop a method for evaluation of the radiation dose of an embryo/fetus during lymphoscintigraphy (sentinel lymph node mapping) in pregnant patients with breast cancer.Material and methods: Two pregnant women (aged 43 and 30) with breast cancer stage IIA (T2N0M0), during the second trimester of pregnancy. We used a lymphotropic colloidal radiopharmaceutical labeled with 99mTc. To evaluate the radiation dose of an embryo, each patient had 6 individual dosimeters, which were placed around the abdomen using an elastic bandage at equal distances around the abdomen. Additionally, we placed the 7th dosimeter, it was placed near the injection site (under the mammary gland). After installing individual dosimeters, radiocolloid was injected into the affected mammary gland at four points (periareolar). The administered activity of radiopharmaceutical was 32.5 MBq, and 51.5 MBq. Lymphoscintigraphy was performed 1 hour after injection. First patient underwent sector resection of the left breast with SLN biopsy. The second patient underwent right mastectomy with SLN biopsy and breast reconstruction surgery using a tissue expander.Results: Based on the results of the study, the dose rate was calculated, on the basis of which the fetal radiation doses were calculated in both patients. Comparison of the mathematical data of both patients shows that, the calculated and experimental values of radiation exposure to the fetus during the radionuclide study of sentinel lymph nodes practically coincide. The obtained data shows that during pregnancy (280 days) the embryo/fetus will accumulate a natural radiation background dose of 1960 μSv, which is 2 times higher than the dose from the radionuclide study of sentinel lymph nodes. Thus these results verify the safety of SLN biopsy technology in pregnancy.Conclusion: 1. Radionuclide diagnostic studies of pregnant women determine radiation doses to the embryo/fetus that do not cause any radiation-induced effects in the prenatal period, and the probability of the occurrence of stochastic radiation-induced effects is several times lower than the incidence of endogenous cancers. 2. Radionuclide examination of sentinel lymph nodes appears to be safe for the fetus when conducted in pregnant women diagnosed with breast cancer. 3. In Russian Federation this method is used for the first time in pregnant women with diagnosed breast cancer. This technology has not been previously described in Russian literature.

The accuracy of intraoperative frozen section examination of sentinel lymph nodes in squamous cell cancer of the vulva

<h3>Objectives:</h3> To measure the diagnostic accuracy of intraoperative frozen section examination of sentinel lymph nodes (SLN) in vulvar cancer and to describe associated patient outcomes. <h3>Methods:</h3> This retrospective cohort study included patients with invasive squamous cell carcinoma of the vulva who underwent SLN biopsy with intraoperative frozen section at one cancer centre from Jan 2008 - Feb 2020. Exclusion criteria were tumor size >4cm, multifocal tumor, palpable groin lymph nodes and neoadjuvant therapy. The SLN procedure was performed by injection of the primary vulvar tumor or scar with technetium-99m, ICG and/or blue dye. We compared the intraoperative SLN frozen section diagnosis and the paraffin section report for concordance. Recurrence location was described and recurrence free survival (RFS) was compared using the Kaplan-Meier method. <h3>Results:</h3> A total of 173 patients (258 groins) met inclusion and exclusion criteria. On frozen section, there were 36/258 positive groins on frozen section and 222 negative groins. On final pathology, there were 39/258 positive groin nodes: 30 macro-metastases, 7 micro-metastases, 2 isolated tumor cells (ITCs). There were 219 negative groins. The sensitivity and specificity for frozen section detecting any metastatic disease compared to final pathology, was 89.7% and 99.5%, respectively. The positive-predictive value (PPV) was 97.2% and the negative-predictive-value (NPV) was 98.2%. There were 4 cases of false negative frozen section where final pathology revealed two cases of ITCs, 1 micro-metastasis and 1 macro-metastasis. A total of 30 patients (17.3%) underwent a full inguinal femoral lymphadenectomy during the same operation due to the frozen section results and avoided a second operation. A total of 2 patients (1.2%) required a second operation for lymphadenectomy due to false negative results on frozen section. Median (range) follow up was 38.0 (1-137.8) months. Median RFS was 14.9 (3.6 to 98.2) months. There were 46 recurrences in the study population, of which 29 were confined to the vulva, 9 groin recurrences and 8 distant recurrences. Among patients with a negative SLN biopsy on both frozen section and final pathology, there were 10 (3.9 %) groin and/or distant recurrences. A total of 6 nodal recurrences were ipsilateral, 1 was contralateral, 2 were bilateral and 1 recurrence was distant. After exclusion of patients with local recurrence only, the RFS at 3 years was 91.6% (95% CI 86.2-97.4%) for patients with negative SLN on frozen section and 64.6% (95% CI 46.5-89.7%) for positive SLN on frozen section. On final pathology, patients with negative SLN had a 3-year RFS of 91.7% (95% CI 86.3-97.4%), macro-metastases 58.4% (95% CI 38.5-87.7%), and micro-metastases/ITCs was 100%. <h3>Conclusions:</h3> Intraoperative frozen section of SLNs in vulvar cancer is an accurate intraoperative guide to determine if complete inguinal femoral lymphadenectomy should be performed. SLN biopsy reduced the need for a second surgical procedure and does not appear to compromise patient outcomes.

The importance of sentinel lymph node biopsy following neoadjuvant chemotherapy in patients with breast cancer: prospective multicentre trial.

The role of sentinel lymph node biopsy (SLNB) in patients with breast cancer after neoadjuvant chemotherapy (NAC) is currently under discussion. The aim of our study was to determine the false negativity rate (FNR) of SLNB, the accuracy of ultrasound examination in the evaluation of the status of lymph nodes and the accuracy of perioperative cryobiopsy of the sentinel lymph node (SLN). Prospective multicentre study, which took place in years 20182020 at three centres in the Czech Republic. A total of 59 patients were evaluated. The FNR of SLNB in the group of patients with cN1 before NAC and ycN0 after NAC was 12.5%. The FNR of perioperative histological examination of the SLN was 38.5%. The FNR of ultrasound examination of axillary lymph nodes in patients after NAC was 35.5%, and the false positivity rate was 16.7%. The incidence of inflammatory complications in our cohort was 3.3%. The FNR of SLNB in the group of patients with cN1 before NAC and ycN0 after NAC exceeds the tolerable limit of 10%. The FNR of perioperative histological examination of the SLN is high; definitive histological examination of the SLN may change the original diagnostic-therapeutic plan. Ultrasound examination of the axillary lymph nodes in patients after NAC is a method with high false negativity and positivity and may not correspond with the perioperative finding. The incidence of inflammatory complications in our cohort in patients after NAC is comparable to literature data on the frequency of complications in patients without NAC.