Clinical Study of Double Contrast-Enhanced Ultrasound Combined with Dye Method and Marker Placement to Identify and Locate Sentinel Lymph Nodes in Patients with Breast Cancer

Objective: To explore the value of percutaneous ultrasonography combined with transvenous ultrasonography for accurate localization of sentinel lymph nodes and diagnosis of metastatic lymph nodes in patients with breast cancer. Methods: 18 cases of patients with breast cancer attending the Hainan General Hospital from May 2022 to June 2024 who were proposed to undergo axillary lymph node dissection were selected, and the ultrasonographic agent was injected subcutaneously through the areola on the 1st day before the operation, and the marker localization of the manifestation of the Sentinel lymph nodes and draw the lymphatic vessel alignment for drainage on the body surface, and record the manifestation of SLN by conventional ultrasound and dual ultrasonography. At the time of surgery, intraoperative melphalan localization was used to identify the SLN, the difference between the number of ultrasound and melphalan localization was observed, and resection was performed for pathological examination to determine whether they were metastatic or not. Results: There were 8 metastatic lymph nodes and 18 non-metastatic lymph nodes among 31 SLN. A total of 62 SLN were localized by intraoperative melphalan, of which 31 were consistent with ultrasound localization and 31 were not identified by ultrasound. The diagnostic sensitivity of SLN metastasis diagnosed by transcutaneous ultrasonography was 62.50%, specificity was 91.30%, positive predictive value was 71.43%, negative predictive value 87.50%, accuracy was 83.87%, and the AUC was 0.769;the diagnostic sensitivityof transvenous ultrasonography diagnosed was 75.00%, specificity was 75.00%, and the accuracy was 83.87%, 75.00%, specificity 91.30%, positive predictive value 75.00%, negative predictive value 91.30%, accuracy 87.10%, AUC 0.832;dual ultrasonography diagnostic sensitivity 87.50%, specificity 91.30%, positive predictive value 77.78%, negative predictive value 95.45%, accuracy 90.32%. The AUC was 0.894. Conclusion: Transcutaneous ultrasonography combined with transvenous ultrasonography can accurately localize sentinel lymph nodes and improve the sensitivity and accuracy of the diagnosis of metastatic SLN.

Interest of SPECT/CT in Detection of Sentinel Lymph Node in Breast Cancer

Aim: Assess the role of hybrid modality SPECT/CT versus planar scintigraphy in sentinel lymph node (SLN) identification in patients with breast cancer. Methods: Planar scintigraphy and hybrid modality SPECT/CT were performed in 23 women with breast cancer (mean age 59.5 years with range 25 - 82 years) with invasive breast cancer (T0, T1 and T2), without clinical evidence of axillary lymph node metastases (N0) and no remote metastases (M0), radiocolloid was injected in four subareolar sites. Planar and SPECT/CT images were separately interpreted. Results: SLNs were detected on lymphoscintigraphy in all patients (100%), taking into consideration both techniques (planar and SPECT-CT images). Planar images identified 45 SLNs in 23 women, with a mean of 1.95 per patient, whereas 56 SLNs were detected on SPECT/CT, increasing this mean to 2.43 per patient. Drainage to internal mammary lymph nodes was seen in 4 patients (17.39%). However, two foci of uptake were identified on planar image as hot SLN in two patients (8.69%);while they have been found as a false positive non-nodal site of uptake on SPECT/CT. Conclusion: SPECT/CT is more focused than planar scintigraphy in the detection of SLN in patients with breast cancer. It detects some lymph nodes not visible on planar images, excludes false positive uptake and exactly locates axillary and non-axillary SLNs.

Sentinel lymph node navigation surgery for gastric cancer: Does it really benefit the patient?

Sentinel lymph node(SLN) navigation surgery is accepted as a standard treatment procedure for malignant melanoma and breast cancer. However, the benefit of reduced lymphadenectomy based on SLN examination remains unclear in cases of gastric cancer. Here, we review previous studies to determine whether SLN navigation surgery is beneficial for gastric cancer patients. Recently, a large-scale prospective study from the Japanese Society of Sentinel Node Navigation Surgery reported that the endoscopic dual tracer method, using a dye and radioisotope for SLN biopsy, was safe and effective when applied to cases of superficial and relatively small gastric cancers. SLN mapping with SLN basin dissection was preferred for early gastric cancer since it is minimally invasive. However, previous studies reported that limited gastrectomy and lymphadenectomy may not improve the patient's postoperative quality of life(QOL). As a result, the benefit of SLN navigation surgery for gastric cancer patients, in terms of their QOL, is limited. Thus, endoscopic and laparoscopic limited gastrectomy combined with SLN navigation surgery has the potential to become the standard minimally invasive surgery in early gastric cancer.

Single skip metastasis in sentinel lymph node: In an early gastric cancer

Lymph node status is considered a key prognostic and predictive factor in patients with gastric cancer(GC).Although there is a practical approach to the intraoperative detection of sentinel lymph nodes(SLNs),such a procedure is not included in the European surgical protocol.In this report,we present a practical approach to SLN mapping in a representative case with early gastric cancer(EGC).A 74-year-old female was hospitalized with an endoscopically observed,superficially ulcerated tumor located in the antral region.Subtotal gastrectomy with D2 lymphadenectomy and SLN mapping was performed by injecting methylene blue dye into the peritumoral submucosal layer.An incidentally detected blue-stained lymph node located along the middle colic artery was also removed.This was detected 40 min after injection of the methylene blue.Histopathologic examination showed a p T1b-staged well-differentiated HER-2-negative adenocarcinoma.All of the 41 LNs located at the first,third,and fifth station of the regional LN compartments were found to be free of tumor cells.The only lymph node with metastasis was located along the middle colicartery and was considered a non-regional lymph node.This incidentally identified skip metastasis indicated stage Ⅳ GC.A classic chemotherapy regimen was given,and no recurrences were observed six months after surgery.In this representative case,low-cost SLN mapping,with a longer intraoperative waiting time,totally changed the stage of the tumor in a patient with EGC.

Sentinel lymph node biopsy for gastric cancer:Where do we stand?

Development of sentinel node navigation surgery (SNNS) and advances in minimally invasive surgical techniques have greatly shaped the modern day approach to gastric cancer surgery.An extensive body of knowledge now exists on this type of clinical application but is principally composed of single institute studies.Certain dye tracers,such as isosulfan blue or patent blue violet,have been widely utilized with a notable amount of success;however,indocyanine green is gaining popularity.The double tracer method,a synchronized use of dye and radio-isotope tracers,appears to be superior to any of the dyes alone.In the meantime,the concepts of infrared ray electronic endoscopy,florescence imaging,nanoparticles and near-infrared technology are emerging as particularly promising alternative techniques.Hematoxylin and eosin staining remains the main method for the detection of sentinel lymph node (SLN) metastases.Several specialized centers have begun to employ immunohistochemical staining for this type of clinical analysis but the equipment costs involving the associated ultra-rapid processing systems is limiting its widespread application.Laparoscopic function-preserving resection of primary tumor from the stomach in conjunction with lymphatic basin dissection navigated by SLN identification represents the current paramount of SNNS for early gastric cancer.Patients with cT3 stage or higher still require standard D 2 dissection.

Up-regulation of hnRNP A1, Ezrin, tubulin β-2C and Annexin A1 in sentinel lymph nodes of colorectal cancer

AIM: To investigate the early metastasis-associated proteins in sentinel lymph node micrometastasis (SLNMM) of colorectal cancer (CRC) through comparative proteome. METHODS: Hydrophobic protein samples were extracted from individual-matched normal lymph nodes (NLN) and SLNMM of CRC. Differentially expressed protein spots were detected by two-dimensional electrophoresis and image analysis, and subsequently identified by matrix assisted laser desorption/ionization-time of flight mass spectrometry-mass spectrometry and Western blotting, respectively.RESULTS: Forty proteins were differentially expressed in NLN and SLNMM, and 4 metastasis-concerned proteins highly expressed in SLNMM were identified to be hnRNP A1, Ezrin, tubulin β-2C and Annexin A1. Further immunohistochemistry staining of these four proteins showed their clinicopathological characteristics in lymph node metastasis of CRC. CONCLUSION: Variations of hydrophobic protein expression in NLN and SLNMM of CRC and increased expression of hnRNP A1, Ezrin, tubulin β-2C and Annexin A1 in SLNMM suggest a significantly elevated early CRC metastasis.

Analysis of factors related to non-sentinel lymph node metastasis in 296 sentinel lymph node-positive Chinese breast cancer patients

Objective: Axillary lymph node dissection(ALND) may be unnecessary in 20%–60% of breast cancer patients with sentinel lymph node(NSLN) metastasis. The aim of the present study was to review the medical records of Chinese patients with early-stage breast cancer and positive NSLN metastasis to identify clinicopathological characteristics as risk factors for non-NSLN metastasis.Methods: The medical records of 2008 early-stage breast cancer patients who received intraoperative sentinel lymph node biopsy(SLNB) between 2006 and 2016 were retrospectively reviewed. These patients were clinically and radiologically lymph nodenegative and had no prior history of receiving neoadjuvant chemotherapy or endocrinotherapy. The clinicopathological characteristics of patients with positive NSLN metastasis who underwent ALND were investigated.Results: In the present study, 296 patients with positive NSLN metastases underwent ALND. Positive non-NSLN metastases were confirmed in 95 patients(32.1%). On univariate analysis, ≥ 3 positive NSLN metastases(P <0.01), NSLN macrometastases(P =0.023), and lymphovascular invasion(P = 0.04) were associated with non-NSLN metastasis(P <0.05). In multivariate analysis, the number of positive SLNs was the most significant predictor of non-SLN metastasis. For patients with 0, 1, 2, or 3 associated risk factors, the non-SLN metastatic rates were 11.5%, 22.5%, 35.2%, and 73.1%, respectively.Conclusions: The number of positive NSLNs, NSLN macrometastases, and lymphovascular invasion were correlated with nonSLN metastasis. The number of positive SLNs was an independent predictor for non-NSLN metastasis. When 2 or 3 risk factors were present in one patient, the probability of non-NSLN was higher than that in the American College of Surgeons Oncology Group Z0011 trial(27.3%); thus, avoiding ALND should be considered carefully.

Near-infrared fluorescence sentinel lymph node detection in gastric cancer: A pilot study

AIM: To investigate feasibility and accuracy of nearinfrared fluorescence imaging using indocyanine green: nanocolloid for sentinel lymph node(SLN) detection in gastric cancer.METHODS: A prospective, single-institution, phaseI feasibility trial was conducted. Patients suffering from gastric cancer and planned for gastrectomy were included. During surgery, a subserosal injection of 1.6 m L ICG:Nanocoll was administered around the tumor. NIR fluorescence imaging of the abdominal cavity was performed using the Mini-FLARE? NIR fluorescence imaging system. Lymphatic pathways and SLNs were visualized. Of every detected SLN, the corresponding lymph node station, signal-to-background ratio and histopathological diagnosis was determined. Patients underwent standard-of-care gastrectomy. Detected SLNs outside the standard dissection planes were also resected and evaluated.RESULTS: Twenty-six patients were enrolled. Four patients were excluded because distant metastases were found during surgery or due to technical failure of the injection. In 21 of the remaining 22 patients, at least 1 SLN was detected by NIR Fluorescence imaging(mean 3.1 SLNs; range 1-6). In 8 of the 21 patients, tumor-positive LNs were found. Overall accuracy of the technique was 90%(70%-99%; 95%CI), which decreased by higher p T-stage(100%, 100%, 100%, 90%, 0% for respectively Tx, T1, T2, T3, T4 tumors). All NIR-negative SLNs were completely effaced by tumor. Mean fluorescence signal-to-background ratio of SLNs was 4.4(range 1.4-19.8). In 8 of the 21 patients, SLNs outside the standard resection plane were identified, that contained malignant cells in 2 patients.CONCLUSION: This study shows successful use of ICG:Nanocoll as lymphatic tracer for SLN detection in gastric cancer. Moreover, tumor-containing LNs outside the standard dissection planes were identified.

Comparison of sentinel lymph node detection performances using blue dye in conjunction with indocyanine green or radioisotope in breast cancer patients: a prospective singlecenter randomized study

Objective:This randomized study aimed to compare the clinical efficacy between the novel dual tracer composed of indocyanine green(ICG)and blue dye(BD)and the conventional dual tracer composed of radioisotope and BD for sentinel lymph node(SLN)mapping in patients with breast cancer.Methods:This study enrolled 471 clinically lymph node-negative patients with primary breast cancer.All patients underwent mastectomy,and those undergoing sentinel lymph node biopsy(SLNB)were randomized to receive blue dye plus radioisotope(RB group)or BD plus ICG(IB group).The detection performances on SLN identification rate,positive SLN counts,detection sensitivity,and false-negative rate were compared between the two groups.Results:In the IB group,97%(194/200)of the patients who underwent the ICG and BD dual tracer injection showed fluorescentpositive lymphatic vessels within 2–5 min.The identification rate of SLNs was comparable between the IB group(99.0%,198/200)and the RB group(99.6%,270/271)(P=0.79).No significant differences were observed in the identification rate of metastatic SLNs(22.5%vs.22.9%,P>0.05,RB group vs.IB group,the same below),positive SLN counts(3.72±2.28 vs.3.91±2.13,P>0.05),positive metastatic SLN counts(0.38±0.84 vs.0.34±0.78,P>0.05),SLNB detection sensitivity(94.4%vs.92.5%,P>0.05),or false-negative rate(5.6%vs.7.5%,P>0.05)between the two groups.Conclusions:ICG can be used as a promising alternative tracer for radioisotope in SLN mapping,and when it is combined with BD in lymphangiography,it offers comparable detection sensitivity compared to the conventional lymphatic mapping strategies that are widely used in clinical practice.

A mini-review on factors and countermeasures associated with false-negative sentinel lymph node biopsies in breast cancer

Sentinel lymph node biopsy （SLNB） is a new surgical technique for local axillary lymph nodes （ALNs） of breast cancer. Large-scale clinical trials have confirmed that undergoing SLNB and ALN dissection （ALND） showed no significant difference for sentinel lymph node （SLN）-negative patients in terms of disease-free survival, overall survival and recurrence-free survival. However, false-negative results are still the main concern of physicians as well as patients who undergo SLNB instead of ALND. The American Society of Breast Surgeons established a task force to suggest acceptable standards for SLNB. In 2000, the task force recommended that the identification rate for SLNB be 85% or higher and the false-negative rate be 5% or lower. This review focuses on clinical factors （tumor volume, multifocal/multi-center cancers, neoadjuvant chemotherapy and skip metastasis）, tracer techniques and pathological factors affecting SLNB and explores methods for reducing the false-negative rate.

Prediction of lymph node metastasis and sentinel node navigation surgery for patients with early-stage gastric cancer

Accurate prediction of lymph node(LN) status is crucially important for appropriate treatment planning in patients with early gastric cancer(EGC). However,consensus on patient and tumor characteristics associated with LN metastasis are yet to be reached. Through systematic search,we identified several independent variables associated with LN metastasis in EGC,which should be included in future research to assess which of these variables remain as significant predictors of LN metastasis. On the other hand,even if we use these promising parameters,we should realize the limitation and the difficulty of predicting LN metastasis accurately. The sentinel LN(SLN) is defined as first possible site to receive cancer cells along the route of lymphatic drainage from the primary tumor. The absence of metastasis in SLN is believed to correlate with the absence of metastasis in downstream LNs. In this review,we have attempted to focus on several independent parameters which have close relationship between tumor and LN metastasis in EGC. In addition,we evaluated the history of sentinel node navigation surgery and the usefulness for EGC.

Accuracy of Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Breast Cancer Patients;Single Center Experience

Purpose: Most important factor affecting prognosis of breast cancer is axillary nodal involvement. Several studies evaluated the accuracy of Sentinel lymph node biopsy in breast cancer patients post neoadjuvant chemotherapy. In this study, we will examine accuracy and feasibility of using Sentinel lymph node biopsy in predicting axillary lymph node status in breast cancer patients after neoadjuvant chemotherapy. Methods: 45 female patients with resectable, nonmetastatic breast carcinoma cases who received neoadjuvant chemotherapy were enrolled in this study according to the routine Mansoura Oncology Center—guidelines of management of breast cancer. Methylene blue dye used for detection of Sentinel lymph node. Results: Successful Sentinel lymph node detection was 82.2%. Skin involvement (T4 disease) were linked to a low identification (P = 0.005). False negative rate equals 11/27 = (40.7%).With advancement of the stage of the tumor, the incidence of false negative results increases significantly (p = 0.012) with 95% confidence interval;1.2 - 5.4. Conclusion: Sentinel lymph node should be adopted to be the standard method for axillary staging with T1-3 tumors after receiving neoadjuvant chemotherapy, in T4 patients, it is associated with low detection rate & high false negative rate making it doubtful technique for axillary staging.

Current Role and Benefits of Sentinel Lymph Node Mapping in Endometrial Cancer

Endometrial cancer (EC) is one of the three major malignant tumors of the female reproductive system in developed countries. In recent years, the incidence of EC ranks first in gynecological malignancy and the mainstay of treatment is Surgery. Although EC has a high prevalence, its several features associated with management are still unclear. Endometrial cancer lymph node status is the most important predictor of survival and also guides postoperative treatment planning but?in gynecologic oncology, lymphadenectomy, as a part of initial surgical management remains controversial. The current introduction of sentinel lymph node mapping in EC patients represents a midway between the execution and omission of node dissection. Sentinel lymph node (SLN) mapping has emerged as an alternative staging strategy hence, the role of SLN mapping is currently being evaluated prospectively in several centers. The objective of this review is to provide an update of the emerging role of sentinel node mapping in EC. In this review, we discussed how several different techniques, type of tracers utilized and injection sites has been described and used for lymphatic mapping in EC impacting on sentinel lymph node detection rates. In addition, we also discussed another evolving field in EC staging i.e.?interpretation of pathologic ultra staging of SLN, which can identify low volume metastasis for which the clinical significance and ideal management remain uncertain. Future perspective regarding EC management is also discussed in this review.

Usefulness of Breast MRI for Safe Omission of Axillary Lymph Nodes Dissection in Sentinel Node-Positive Breast Cancer Patients

Background: Preoperative identification of patients with extensive lymph node metastasis (LNM) is important for safe omission of axillary lymph node dissection (ALND) in sentinel node (SN)-positive (SN+) breast cancer patients. Methods: We evaluated retrospectively the collected data of 758 breast cancer patients who underwent axillary surgery between 2008 and 2017, excluding those who received neoadjuvant chemotherapy. Results: Of the 758 patients, 607 were not suspicious to have LNM by axillary ultrasound (AUS-), but 38 suspicious cases were found by breast magnetic resonance imaging (MRI). Of 15 patients undergoing axillary fine needle biopsy (AFNA) due to second-look axillary ultrasound (AUS), 9 underwent ALND because of a positive AFNA (AFNA+). Among 81 (10.9%) patients undergoing ALND due to SN+ findings, 6 (7.4%) had extensive LNM (LNM ≥ 4). If MRI was not performed, among the 90 of 673 patients undergoing ALND who had SN+ findings, 12 (13.3%) had LNM ≥ 4. Conclusions: The proportion of cases with LNM ≥ 4 was reduced from 13.3% to 7.4% among patients undergoing SN biopsies combined with breast MRI. ALND might be omitted safely in SN+ cases according to detailed preoperative evaluations using additional breast MRI to ultrasound.

Early Results of Omitting Completion Axillary Lymph Node Dissection in Sentinel Lymph Node Metastasis-Positive Breast Cancer Patients

Background: We investigated the early results of omitting completion axillary lymph node dissection (ALND) for axillary node metastasis-negative (N0), sentinel node (SN) metastasis-positive breast cancer patients. Patients and Methods: 489 patients had invasive N0 breast cancer treated without completion ALND, regardless of their SN metastasis status. Analyses included the associations between the SN metastasis status, clinicopathological findings and recurrence, between recurrence and clinicopathological findings, and recurrence-free survival. Results: 430 patients were SN biopsy (SNB)-negative, and 59 were SNB-positive. The SNB-positive patients received significantly more potent adjuvant therapy than the SNB-negative patients. Median follow-up was 3.7 years, and the axillary node recurrence was seen in 6 patients (1.2%) and recurrence in 21 patients. The SN status showed no associations with the clinicopathological findings or recurrence. Univariate analysis showed recurrence was associated with absence of hormonal therapy, ER-negative, PgR-negative, HER2-positive or triple-negative (TNBC) disease, a tumor ≥2.1 cm and higher nuclear grade. Multivariate analysis showed recurrence was associated with absence of hormonal therapy and a tumor ≥2.1 cm. Cox proportional hazards model showed recurrence was extremely early in ER-negative and TNBC patients. Conclusion: Completion ALND can be skipped in N0 breast cancer patients even if they are SNB-positive, but adjuvant therapy is essential.

Recent Advances in the Tracer Technology Used for Sentinel Lymph Node Biopsy in Breast Cancer

The high incidence of breast cancer poses one of the greatest risks to female health worldwide. Sentinel lymph node biopsy (SLNB) is the standard of treatment for patients with axillary lymph node-negative early-stage breast cancer. Herein, the precise use of tracers is the key to ensuring the success of SLNB. However, owing to select-few limitations of traditional tracers, their clinical application is limited. New tracer techniques, such as the near-infrared fluorescent dye method (using indocyanine green), contrast-enhanced ultrasound, and superparamagnetic iron oxide nanoparticles are being applied in clinical practice. In this paper, we review the recent progress in SLNB tracer technology.

Detection of micrometastases in bone marrow and sentinel lymph nodes of breast cancer patients

To study the sensitivity and clinical significance of HE-staining,IHC and RT-PCR in detecting breast cancer micrometastases in bone marrow and sentinel lymph nodes （SLNs）. Methods ：After general anesthesia, all patients underwent bone marrow puncture and sentinel lymph node biopsy （SLNB） by 1% isosulfan blue, and then HE-staining,IHC and RT-PCR were used to detect micrometastases. Results：Of 62 patients with breast cancer whose axillary lymph nodes showed negative HE-staining results, 15 cases presented with positive RT-PCR and 9 cases showed positive IHC results positive in bone marrow micrometastases detection. PT-PCR and IHC showed good uniformity（kappa=0.6945）and there was significant difference in detective rate between these two methods （X2=4.1667,P = 0.0412）. In SLN samples, 13 showed positive RT-PCR results, while 7 showed positive IHC results. PT-PCR and IHC showed good uniformity （kappa=0.64.83）and significant difference was also found in detective rate between these two methods （X^2=4.1667 ,P = 0.0412）. Both bone marrow and SLN samples were RT-PCR positive in 3 cases, which indicated that bone marrow did not always accompany SLN micrometastases（X^2=0.067,P = 0.796）. Conclusion： Even if no axillary lymph node involvement or distant metastases are present in routine preoperative examination, micrometastases can still be detected in bone marrow or SLNs. Because the bone marrow micrometastases and axillary node micrometastses are not present simultaneously, combination test of multiple indicators will detect micrometastases more accurately.

Sentinel lymph node mapping of a breast cancer of the vulva: Case report and literature review

Ectopic breast tissue is rare and typically presents as an axillary mass. Previous reports have identified ectopic breast tissue in the vulva, but malignancy is exceedingly uncommon. We present a 62 years old with locally advanced breast carcinoma arising in the vulva demonstrates the utilization of sentinel lymph node mapping to identify metastatic lymph nodes previously unable to be identified via traditional surgical exploration.Our case supports the principles of adjuvant therapy for breast cancer to be applied to ectopic breast cancer arising in the vulva. A literature review highlights common key points in similar cases to guide management.

The Initial Implementation of the Sentinel Lymph Node Biopsy (SLNB) for Breast Cancer Management in Malta

Over the past two decades, the sentinel lymph node biopsy (SLNB) based on sentinel node (SN) being the first lymph node that harbors metastases, revolutionized breast cancer management. SLNB presents much less morbidity when compared to radical axillary lymph node dissection (ALND) where all nodes are dissected irrespective of their metastatic involvement. The purpose of this study was to evaluate the effectiveness of SLNB by investigating whether the histological characteristics of the SNs identified using scintigraphy are predictive of the histological characteristics of the ALN basin. Methods: Fifty-five female breast cancer patients underwent lymphoscintigraphy and SLNB followed by ALND. The histological status of the SN/s was correlated to the histological status of the ALNs to determine whether the SN accurately stages the ALNs in breast cancer. Results: During surgery, SNs were successfully isolated in 52 out of 55 cases (94.5%) (range, 0 to 9). No SNs were identified in 3 cases (5.5%). Results demonstrate a significant association (p = 0.05) between the metastatic status of SNs and the corresponding ALNs in 42 out of 52 patients (80.8%), but with a high false-negative rate (FNR) of 37.5%. Conclusion: The findings of this study show that the sentinel node concept provides the benefits of SLNB in the majority of instances. However, further work is required in reducing the FNR. Once the effectiveness of SLNB as a staging technique is locally established, the need of ALND in SN-negative patients would be limited, thus improving the quality of life of Maltese breast cancer patients.

Location of Sentinel Lymph Node in Gastric Cancer:A Modified,Painless And Noninvasive Approach

Objective： The presence of lymph node metastases is an important factor in the prognosis of gastric cancer patient. Therefore, the precise identification of sentinel lymph nodes （SLN） in these patients is critical. In this work, we investigated the feasibility and preciseness by injection of 99mTc-sulfur colloid （SC） 2 hours before operation after general anesthesia, instead of one day before surgery. Methods： Thirty-one patients of gastric cancer diagnosed as T1-T3 were enrolled in this study. During operation, a SLN was defined as those containing 10 times more radioactivity than surrounding tissue with a hand-held gamma probe and removed. All the patients underwent radical gastrectomy with extended lymphadenectomy. All resected nodes were examined postoperatively by routine H＆E stain and those negative SLNs were examined with further cytokeratin immunohistochemistical staining. Results： The incidence of metastasis was significantly higher in SLNs than in non-SLNs （x2=67.48, P〈0.001）. The overall sensitivity, specificity and accuracy of the SLN status in the diagnosis of the lymph node status of the patient were 86.36%, 100% and 96.77%, respectively. The positive predictive value and negative predictive value of SLN biopsy were 100%, and 75.0%, respectively. SLNs were used to diagnose the lymph node status with 100% accuracy in the T1 group. In the T2 and T3 groups, the sensitivity, specificity, and diagnostic accuracy were 92.3%, 100%, and 94.44%, 60.0%, 100%, and 66.66%, respectively. Most of the SLNs were located in the #1, #2, #3, #4, #5, and #6, except in 3 patients （9.68%）.With cytokeratin immunohistochemical staining, lymphatic pathologic staging in 1 patient was upstaged. Conclusion： SLN biopsy with the above approach is a feasible and accurate diagnostic procedure for detecting lymph node metastasis in patients with gastric cancer, which is painless, noninvasive, easily accepted by patients and suitable for extensive clinical applications.