Current status of sentinel lymph node navigation surgery in breast and gastrointestinal tract

Near-Infrared Fluorescence Image-Guided Surgery in Esophageal and Gastric Cancer Operations

Background

Near-infrared fluorescence image-guided surgery helps surgeons to see beyond the classical eye vision. Over the last few years, we have witnessed a revolution which has begun in the field of image-guided surgery.

Purpose, and Research design

Fluorescence technology using indocyanine green (ICG) has shown promising results in many organs, and in this review article, we wanted to discuss the 6 main domains where fluorescence image-guided surgery is currently used for esophageal and gastric cancer surgery.

Study sample and data collection

Visualization of lymphatic vessels, tumor localization, fluorescence angiography for anastomotic evaluation, thoracic duct visualization, tracheal blood flow analysis, and sentinel node biopsy are discussed.

Conclusions

It seems that this technology has already found its place in surgery. However, new possibilities and research avenues in this area will probably make it even more important in the near future.

A Novel and Effective Model to Predict Skip Metastasis in Papillary Thyroid Carcinoma Based on a Support Vector Machine

INTRODUCTION

Skip metastasis, referred to as lymph node metastases to the lateral neck compartment without involvement of the central compartment, is generally unpredictable in papillary thyroid carcinoma (PTC). This study aims to establish an effective predictive model for skip metastasis in PTC.

METERIALS AND METHODS

Retrospective analysis was performed of clinical samples from 18192 patients diagnosed with thyroid cancer between 2016 to 2020. The First Affiliated Hospital of Wenzhou Medical University. The lateral lymph node metastasis was occureed in the training set (630 PTC patients) and validation set (189 PTC patients). The univariate and multivariate analyses were performed to detect the predictors of skip metastasis and the support vector machine (SVM) was used to establish a model to predict skip metastasis.

RESULTS

The rate of skip metastasis was 13.3% (84/631). Tumor size (≤10 mm), upper location, Hashimoto's thyroiditis, extrathyroidal extension, absence of BRAFV600E mutation, and less number of central lymph node dissection were considered as independent predictors of skip metastasis in PTC. For the training set, these predictors performed with 91.7% accuracy, 86.4% sensitivity, 92.2% specificity, 45.2% positive predictive value (PPV), and 98.9% negative predictive value (NPV) in the model. Meanwhile, these predictors showed 91.5% accuracy,71.4% sensitivity, 93.1% specificity, 45.5% PPV, and 97.6% NPV in validation set.

CONCLUSION

This study screened the predictors of the skip lateral lymph node metastasis and to establish an effective and economic predictive model for skip metastasis in PTC. The model can accurately distinguish the skip metastasis in PTC using a simple and affordable method, which may have potential for daily clinical application in the future.

Evaluation of lymph node metastasis in a rabbit tumor model: correlations between contrast-enhanced ultrasound and pathologic findings

Purpose

The purpose of this study was to evaluate the ability of contrast-enhanced ultrasonography (CEUS) with microbubbles to detect metastatic lymph nodes (LNs) for treatment planning and prognosis.

Methods

For the metastatic LN model, ground VX₂ tumor tissues were injected subcutaneously in 12 rabbits, just below the right hind limb. The rabbits were classified into three groups based on the LN area: group A (n=4, >1.9 cm² ), group B (n=4, 1-1.9 cm² ), and group C (n=4, <1 cm² ). The LNs were monitored on CEUS for 10 seconds after injecting 2.5 mL of microbubbles. The percent area of metastatic LNs was calculated on pathologic images and compared with CEUS images.

Results

In group A, the mean percent area of metastasis was 40.7%±19.4%. In all cases of metastasis, round-shaped perfusion defects were clearly observed in CEUS images. The metastatic areas were strongly correlated with pathologic findings. The mean percent area in group B was 21.5%±14.4%. The CEUS findings showed multiple nodular perfusion defects, clearly revealing the metastatic areas. In group B, the CEUS and pathologic findings were concordant for three of the four cases. The mean percent area in group C was 9.1%±6.4%. However, in this group, CEUS only detected a small perfusion defect in one case.

Conclusion

CEUS has the potential to depict characteristic imaging features of metastatic LNs but still has limitations in early detection.

Secondary sentinel lymph node tracing technique: a new method for tracing lymph nodes in radical gastrectomy for advanced gastric cancer

OBJECTIVE

To explore the feasibility and clinical value of secondary sentinel lymph node (SSLN) tracing technique in radical gastrectomy for advanced gastric cancer (AGC).

METHODS

From January 2009 to June 2011, 247 patients who suffered from gastric angle cancer with metastasis in No. 3 group lymph nodes were divided randomly into groups A and B. Methylthioninium chloride was injected into the peripheral tissue of the metastatic No. 3 group lymph nodes of 138 patients in group A before tumor resections. SSLNs were traced and individual lymphadenectomies were carried out based on the biopsy results of the SSLNs. Standard D2 radical gastrectomies were carried out directly on 109 patients in group B. Postoperative follow-up and survival analysis were carried out for patients in both groups.

RESULTS

SSLNs were found in 114 (82.6%) patients in group A. Ninety of those patients (78.9%) demonstrated existing metastasis in SSLNs. According to Kaplan-Meier's method, the postoperative 3-year cumulative survival rates were 63.5% and 47.5%, and the median survival time were 40 and 36 months for the patients of groups A and B, respectively (P<0.05).

CONCLUSIONS

The SSLN tracing technique is feasible in radical gastrectomy for AGC. It gives surgeons important information about the terminal status of lymph node metastasis and provides some scientific basis for individual lymphadenectomy.

Targeted Dual-Modality Imaging in Renal Cell Carcinoma: An Ex Vivo Kidney Perfusion Study

PURPOSE

Antibodies labeled with both a near-infrared fluorescent dye and a radionuclide can be used for tumor-targeted intraoperative dual-modality imaging. Girentuximab is a chimeric monoclonal antibody against carbonic anhydrase IX (CAIX), an antigen expressed in 95% of clear cell renal cell carcinoma (ccRCC). This study aimed to assess the feasibility of targeted dual-modality imaging with (111)In-girentuximab-IRDye800CW using ex vivo perfusion of human tumorous kidneys.

EXPERIMENTAL DESIGN

Seven radical nephrectomy specimens from patients with ccRCC were perfused during 11 to 15 hours with dual-labeled girentuximab and subsequently rinsed during 2.5 to 4 hours with Ringer's Lactate solution. Then, dual-modality imaging was performed on a 5- to 10-mm-thick lamella of the kidney. Fluorescence imaging was performed with a clinical fluorescence camera set-up as applied during image-guided surgery. The distribution of Indium-111 in the slice of tumor tissue was visualized by autoradiography. In two perfusions, an additional dual-labeled control antibody was added to demonstrate specific accumulation of dual-labeled girentuximab in CAIX-expressing tumor tissue.

RESULTS

Both radionuclide and fluorescence imaging clearly visualized uptake in tumor tissue and tumor-to-normal tissue borders, as confirmed (immuno)histochemically and by gamma counting. Maximum uptake of girentuximab in tumor tissue was 0.33% of the injected dose per gram (mean, 0.12 %ID/g; range, 0.01-0.33 %ID/g), whereas maximum uptake in the normal kidney tissue was 0.04 %ID/g (mean, 0.02 %ID/g; range, 0.00-0.04 %ID/g).

CONCLUSIONS

Dual-labeled girentuximab accumulated specifically in ccRCC tissue, indicating the feasibility of dual-modality imaging to detect ccRCC. A clinical study to evaluate intraoperative dual-modality imaging in patients with ccRCC has been initiated. Clin Cancer Res; 22(18); 4634-42. ©2016 AACR.

Usefulness of CT-lymphography in sentinel lymph node navigation

BACKGROUND

There are many methods for sentinel lymph node (SLN) navigation. The methods using radioisotopes and blue dyes are performed mainly for the identification of SLN. Our current method for SLN biopsy is a combination of three techniques with 99mTc-phytate, patent blue V dye, and preoperative CT-lymphography (CTLG).

PATIENTS AND METHODS

Iomeprol (Iomeron®) as a water-soluble contrast agent is diluted twofold with 1 % lidocaine and intradermally injected into a few sites (2-5 ml at each site) around the tumor. After the injection, CT imaging is performed using a 64-row MDCT system (Siemens SOMATOM Definition AS+). We performed CTLG in 34 patients (16 men, 18 women) between September 2008 and March 2013.

RESULTS

CTLG clearly visualized the SLN and the lymphatic drainage in 21 out of 34 patients.

CONCLUSIONS

We can detect the SLN and lymphatic flow near to tumors without shine-through effect, especially in the head and neck regions. It is thought that CTLG may be useful to determine the range of lymph node dissection.

Triple assessment of sentinel lymph node metastasis in early breast cancer using preoperative CTLG, intraoperative fluorescence navigation and OSNA

BACKGROUND

Sentinel lymph node biopsy (SLNB) became a standard surgical procedure for patients with early breast cancer; however, the optimal method of sentinel lymph node (SLN) identification remains controversial. The current study presents the protocol of our institution for preoperative and intraoperative SLN detection.

METHODS

Fifty female patients with early breast cancer and clinically node-negative axilla were enrolled in this study. All patients underwent preoperative CT lymphography (CTLG), intraoperative SLNB using fluorescence navigation, intraoperative one-step nucleic acid amplification (OSNA) and postoperative hematoxylin and eosin histopathological analysis. Prediction of metastasis by CTLG and detection of metastasis by OSNA were compared to results of histopathology as standard reference.

RESULTS

SLN were identified by preoperative CTLG and intraoperative SLNB with fluorescence navigation in all patients, the identification rate was 100 %. SLN metastases were detected as positive by OSNA in 9 patients (18 %), 4 were (++), 4 were (+) and 1 was (+I). SLN metastases were detected as positive by histopathology in 10 patients (20 %). The concordance rate between OSNA and permanent sections was 90 %. The negative predictive value of CTLG was 80 %.

CONCLUSION

Use of CTLG and fluorescence navigation made performing SLNB with high accuracy possible in institutions that cannot use the radioisotope method. OSNA provided accurate intraoperative method, allowing for completion of axillary node dissection during surgery and avoidance of second surgical procedure in patients with positive SLNs, thereby reducing patient distress and, finally, saving hospital costs.

Sentinel node mapping of VX2 carcinoma in rabbit thigh with CT lymphography using ethiodized oil

OBJECTIVE

To assess the feasibility of computed tomography (CT) lymphography using ethiodized oil for sentinel node mapping in experimentally induced VX2 carcinoma in the rabbit thigh.

MATERIALS AND METHODS

This experiment received approval from the institutional animal use and care administrative advisory committee. Twenty-three rabbits with VX2 carcinoma in the thigh underwent CT before and after (1 hour, 2 hour) peritumoral injection of 2 mL ethiodized oil. After the CT examination, sentinel nodes were identified by peritumoral injection of methylene blue and subsequently removed. The retrieved sentinel and non-sentinel lymph nodes were investigated with radiographic and pathologic examinations. Based on the comparison of CT findings with those of radiographic and pathologic examinations, the diagnostic performance of CT for sentinel node identification was assessed.

RESULTS

All 23 rabbits showed 53 ethiodized oil retention nodes on post-injection CT and specimen radiography, and 52 methylene blue-stained nodes at the right femoroiliac area. Of the 52 blue-stained sentinel nodes, 50 nodes demonstrated ethiodized oil retention. Thus, the sentinel node detection rate of CT was 96% (50 of 52). On pathologic examination, 28 sentinel nodes in 17 rabbits (nodes/rabbit, mean ± standard deviation, 1.7 ± 0.6) harbored metastasis. Twenty seven of the 28 metastatic sentinel nodes were found to have ethiodized oil retention.

CONCLUSION

Computed tomography lymphography using ethiodized oil may be feasible for sentinel node mapping in experimentally induced VX2 carcinoma in the rabbit thigh.

Computed tomographic lymphography for sentinel lymph node biopsy in male breast cancer: report of two cases

Male breast cancer is rare, accounting for less than 1% of breast cancers. Because of its rarity evidence of the usefulness sentinel lymph node biopsy (SLNB) for male breast cancer has not been established. Moreover, a navigation system which can easily determine the incision site of SLNB is needed because a second incision for SLNB is necessary in most cases. We report successful computed tomographic lymphography (CTLG)-guided SLNB in two male breast cancer cases: the first patient was a 79-year-old man and the second was a 64-year-old man. Both had presented with a lump behind the nipple. Clinical diagnoses were early breast carcinoma in both cases. The second patient took tamoxifen 20 mg daily as neoadjuvant endocrine therapy. SLNs were clearly visualized by CTLG, allowing mastectomies with SLNB to be performed. Both SLNB were negative, such that axillary lymph node dissection was not needed. Preoperative CTLG is useful for visualizing lymph flow and detecting SLN in male breast cancer.

The new era of staging as a key for an appropriate treatment for esophageal cancer

Fluorodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) have become the gold standard for staging of esophageal cancer by detecting distant metastases, but metastatic lymph nodes are often difficult to diagnose from the size and standardized uptake value (SUV). If we compare the diagnostic performance of endoscopic ultrasonography (EUS), CT, and FDG-PET in staging of esophageal cancer, EUS is the most sensitive method to identify the detection of regional lymph node metastases, whereas CT and FDG-PET are more specific tests. Combination study with CT, EUS and PETCT cannot make a precise diagnosis after neoadjuvant therapy (NAT). A precise staging might be determined by the fine needle aspiration biopsy (FNAB) under EUS and US screening in the neck and the abdomen even after NAT. Indication of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) for superficial cancer is sensitive because of difficulty in T1b cancer diagnosis. Detailed examination about vessel invasion and the possibility of residual tumor with dissected specimen will offer an appropriate additional therapy. New strategy like sentinel lymph node (SLN) navigation could supply more information about lymphatic routes and metastatic nodes. SLN navigation with ESD might become a new less invasive strategy for superficial esophageal cancer.

Early gastric cancer: feasibility of CT lymphography with ethiodized oil for sentinel node mapping

PURPOSE

To evaluate the feasibility of CT lymphography with ethiodized oil for sentinel node mapping in porcine stomachs and in patients with early gastric cancer.

MATERIALS AND METHODS

Approval for the animal study was obtained from the authors' institutional animal use and care administrative advisory committee, the clinical study was approved by the institutional review board, and informed consent was obtained from each participant. Five pigs underwent CT lymphography 1 hour after gastric subserosal injection of 1 mL ethiodized oil and sentinel node mapping with injection of 1 mL methylene blue. Ethiodized oil retention nodes were identified on the radiographic images of the gastric specimen and removed for histopathologic examination. In addition, 10 patients with early gastric cancer underwent CT lymphography with peritumoral injection of 1 mL ethiodized oil, followed by sentinel basin extirpation with CT and routine nodal dissection. The removed sentinel basins were examined by radiography. Histopathologic examination was performed for dissected nodes, including sentinel nodes.

RESULTS

In each of the five pigs, CT showed one perigastric ethiodized oil retention node. After harvesting the ethiodized oil retention node, blue-stained areas were identified in the five removed nodes and intranodal ethiodized oil was detected on histopathologic examination. In all 10 patients, CT lymphography with ethiodized oil successfully defined the sentinel basin with ethiodized oil retention nodes. CT lymphography revealed 20 ethiodized oil retention nodes. After basin extirpation, 28 and 46 nodes were detected on radiographic and histopathologic examinations. Histopathologic examination revealed that one patient had micrometastases at two sentinel nodes and another patient had isolated tumor cells at one sentinel node. No patient had metastasis in nonsentinel nodes.

CONCLUSION

CT lymphography with ethiodized oil may be a feasible method for sentinel node mapping in patients with early gastric cancer.

Animal model for training in sentinel lymph node biopsy of the stomach through combined methods

PURPOSE

Create and validate a proposed animal model for training in sentinel lymph node biopsy of the stomach.

METHODS

In thirty-two rabbits, through a laparotomy, they received a subserosal injection of 0.1 ml of phytate labeled with technetium-99m (0.2 mCi) in the anterior wall of the gastric corpus, followed by 0.2 ml of Blue Patent V(®) 2.5%, through the same puncture site. Suspicious lymph nodes were searched in vivo at five, ten and 20 minutes, both visually (Blue Patent stained lymph nodes) and with a manual gamma radiation detector (to detect suspected radioactive lymph nodes). After 20 minutes, was performed resection of these for further evaluation of radioactivity (ex vivo) and histological study.

RESULTS

Lymph nodes were identified in 30 rabbits (Average of 2.2 lymph nodes per animal). Of the 90 suspected lymph nodes that occurred in the study, 70 cases (77.8%) were histologically confirmed for lymphoid tissue. Of these, the majority were located in the periesophageal region of the gastric fundus. The sample presented a mortality rate of 6.25% and nine complications related to the method, which interfered in the identification of the lymph nodes.

CONCLUSION

The animal model for sentinel node biopsy in rabbit stomachs proved to be feasible, with low complexity and reproduced the difficulties encountered for gastric lymph node biopsy in humans, being adequate for surgical training.

Injection of methylene blue solution into the inferior mesenteric artery of resected rectal specimens for rectal cancer as a method for increasing the lymph node harvest

BACKGROUND

The aim of the present study was to determine whether the injection of methylene blue solution into the inferior mesenteric artery could improve the lymph node harvest in rectal specimens of rectal cancer patients treated with rectal resection with total mesorectal excision.

METHODS

The study group consisted of 20 randomly selected fresh rectal specimens from patients with stages I-III rectal cancer treated at the Surgery Clinic at the Institute of Oncology of Vilnius University during the period from February 2008 to December 2010, and 20 specimens were selected under the same conditions to serve as the control group. The patients underwent conventional rectal resection with total mesorectal excision and coloanal anastomosis for low rectal cancer performed by the same surgeon, did not receive preoperative radiotherapy and had no distant metastases. After the removal of the specimen, 30 ml of 0.5% methylene blue solution was injected into the inferior mesenteric artery of the specimens in the study group (methylene blue group). The specimens from both the methylene blue and control groups were examined using the standards established by the Lithuanian National Centre of Pathology. The pathologist was not required to make any special macroscopic preparations. A retrospective analysis of clinical and histopathological records was performed.

RESULTS

Comparison of the mean lymph node harvest showed a significant difference between methylene blue and control groups with average lymph node numbers per specimen of 18 ± 5 and 14 ± 6, respectively (p = 0.025). The specimens from 12 of the 20 patients in the methylene blue group and the specimens from 7 of the 20 patients from the control group had positive nodes.

CONCLUSIONS

Injecting methylene blue solution into the inferior mesenteric artery is an efficient and simple method for improving the lymph node harvest in the histopathological examination of rectal specimens of rectal cancer patients treated with rectal resection with total mesorectal excision.

Local tissue reaction after injection of contrast media on gastric wall of mouse: experimental study for application of contrast media to computed tomography lymphography

Purpose

Computed tomography (CT) lymphography is a simple technique of sentinel node navigation but tissue reaction after injection of contrast media has not been reported yet.

Methods

Ninety mice used in this study were divided into three groups: lipiodol, iopamidol, and normal saline. The test compounds were given by submucosal injection to the gastric wall of anesthetized mice. The specimens were subjected to histopathological examination.

Results

The mean grades of acute inflammatory response after iopamidol and lipiodol injection were significantly higher than control group. However, there was no significant difference between iopamidol and lipiodol injection. The mean grade of chronic inflammatory response and fibrosis showed no differences between groups. The presence or absence of fibrinoid necrosis and mesothelial hyperplasia showed no statistical differences at each time point between groups. The foam cell, which is similar to human signet ring cell carcinoma, were not identified in normal saline and iopamidol group, but were detected by postoperative day 7 in lipiodol group.

Conclusion

We conclude that iopamidol and lipiodol when used as a contrast media of CT lymphography is an available material for preoperative sentinel node navigation surgery for gastric cancer with an acceptable incidence of pathological alterations in a mouse model. Our results are potentially useful to clinical (human) application.

Sentinel lymph node biopsy using intraoperative indocyanine green fluorescence imaging navigated with preoperative CT lymphography for superficial esophageal cancer

BACKGROUND

The sentinel lymph node (SLN) concept has been gaining attention for gastrointestinal neoplasms but remains controversial for esophageal cancer. This study evaluated the feasibility of SLN identification using intraoperative indocyanine green (ICG) fluorescence imaging (IGFI) navigated by preoperative computed tomographic lymphography (CTLG) to treat superficial esophageal cancer.

METHODS

Subjects comprised 20 patients clinically diagnosed with superficial esophageal cancer. Five minutes after endoscopic submucosal injection of iopamidol around the primary lesion using a four-quadrant injection pattern with a 23-gauge endoscopic injection sclerotherapy needle, three-dimensional multidetector computed tomography was performed to identify SLNs and lymphatic routes. ICG solution was injected intraoperatively around the tumor. Fluorescence imaging was obtained by infrared ray electronic endoscopy. Thoracoscope-assisted standard radical esophagectomy with lymphadenectomy was performed to confirm fluorescent lymph nodes detected by CTLG.

RESULTS

Lymphatic vessels and SLNs were identified preoperatively using CTLG in all cases. Intraoperative detection rates were 100% using CTLG and 95% using IGFI. Lymph node metastases were found in four cases, including one false-negative case with SLNs occupied by bulky metastatic tumor that were not enhanced with both methods. The other 19 cases, including three cases of metastatic lymph nodes, were accurately identified by both procedures.

CONCLUSIONS

Preoperative CTLG visualized the correct number and site of SLNs in surrounding anatomy during routine computed tomography to evaluate distant metastases. Referring to CTLG, SLNs were identified using IGFI, resulting in successful SLN navigation and saving time and cost. This method appears clinically applicable as a less-invasive method for treating superficial esophageal cancer.

High FOXP3+ regulatory T-cell density in the sentinel lymph node is associated with downstream non-sentinel lymph-node metastasis in gastric cancer

Background:

We aimed to evaluate the immunologic nature of sentinel lymph nodes (SLNs) in gastric cancer patients and to determine whether it can predict non-SLN metastasis.

Methods:

Sentinel lymph node samples were collected from 64 gastric carcinoma patients who had undergone gastrectomy with SLN biopsy. One representative SLN sample was selected from each patient and was subjected to immunostaining for CD8, CD57, FOXP3, and DC-LAMP. The numbers of marker-positive cells in each sample were counted. The relationships between various immune cell densities and clinicopathologic parameters or metastasis status of SLNs and non-SLNs were sought.

Results:

High FOXP3+ Treg density of the SLN was found to be significantly associated with the presence of metastasis in either SLNs or non-SLNs. DC-LAMP+ cell density of the SLN was the highest at the isolated tumours cell level, and this decreased along with an increase in tumour metastasis in either SLNs or non-SLNs. Univariate and multivariate logistic regression models revealed that high FOXP3+ Treg density of the SLN was an independently significant predictor of non-SLN metastasis.

Conclusions:

This study is the first to indicate an important role of SLNs in metastatic dissemination of gastric cancer. Our findings suggest that Tregs could be a new therapeutic target for regulating the metastasis of gastric cancer.

Assessment of cervical lymph node metastases using indirect computed tomography lymphography with iopamidol in a tongue VX2 carcinoma model

OBJECTIVE

To investigate the performance of indirect computed tomography lymphography with iopamidol for detecting cervical lymph node metastases in a tongue VX2 carcinoma model.

MATERIALS AND METHODS

A metastatic cervical lymph node model was created by implanting VX2 carcinoma suspension into the tongue submucosa of 21 rabbits. Computed tomography images were obtained 1, 3, 5, 10, 15 and 20 minutes after iopamidol injection, on days 11, 14, 21 (six rabbits each) and 28 (three rabbits) after carcinoma transplantation. Computed tomography lymphography was performed, and lymph node filling defects and enhancement characteristics evaluated.

RESULTS

Indirect computed tomography lymphography revealed bilateral enhancement of cervical lymph nodes in all animals, except for one animal imaged on day 28. There was significantly slower evacuation of contrast in metastatic than non-metastatic nodes. A total of 41 enhanced lymph nodes displayed an oval or round shape, or local filling defects. One lymph node with an oval shape was metastatic (one of 11, 9.1 per cent), while 21 nodes with filling defects were metastatic (21/30, 70 per cent). The sensitivity, specificity, accuracy, and positive and negative predictive values when using a filling defect diameter of 1.5 mm as a diagnostic criterion were 86.4, 78.9, 82.9, 82.6 and 83.3 per cent, respectively.

CONCLUSION

When using indirect computed tomography lymphography to detect metastatic lymph nodes, filling defects and slow evacuation of contrast agent are important diagnostic features.

The extent of lymph node dissection for gastric cancer: a critical appraisal

The extent of lymphadenectomy during therapeutic gastrectomy for gastric cancer remains a protracted and controversial issue. While traditionally extended lymphadenectomy is performed in Eastern Asia, limited lymphadenectomy is advocated by most western surgeons. Two large western randomized trials, meta-analyses and a recent systematic review were unable to demonstrate overall benefit from extended lymphadenectomy. In this review, the currently available data on this topic are critically evaluated, while ongoing studies and future perspective are discussed.

Uniform silica coated fluorescent nanoparticles: synthetic method, improved light stability and application to visualize lymph network tracer

Background

The sentinel lymph node biopsy (SLNB) was developed as a new modality in the surgical diagnosis of lymph node metastases. Dye and radioisotope are major tracers for the detection of sentinel lymph nodes (SLN). Dye tends to excessively infiltrate into the interstitium due to their small size (less than several nanometers), resulting in difficulties in maintaining clear surgical fields. Radioisotopes are available in limited number of hospitals. Fluorescent nanoparticles are good candidates for SLN tracer to solve these problems, as we can choose suitable particle size and fluorescence wavelength of near-infrared. However, the use of nanoparticles faces safety issues, and many attempts have been performed by giving insulating coats on nanoparticles. In addition, the preparation of the uniform insulating layer is important to decrease variations in the quality as an SLN tracer.

Methodology/Principal Findings

We herein succeeded in coating fluorescent polystyrene nanoparticles of 40 nm with uniform silica layer of 13 nm by the modified Stöber method. The light stability of silica coated nanoparticles was 1.3-fold greater than noncoated nanoparticles. The popliteal lymph node could be visualized by the silica coated nanoparticles with injection in the rat feet.

Conclusions/Significance

The silica coated nanoparticles in lymph nodes could be observed by transmission electron microscope, suggesting that our silica coating method is useful as a SLN tracer with highly precise distribution of nanoparticles in histological evaluation. We also demonstrated for the first time that a prolonged enhancement of SLN is caused by the phagocytosis of fluorescent nanoparticles by both macrophages and dendritic cells.

Sentinel lymph node biopsy in breast cancer guided by indocyanine green fluorescence (Br J Surg 2009; 96: 1289-1294)

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Optimum lymph node dissection in clinical T1 and clinical T2 colorectal cancer

PURPOSE

On the basis of a retrospective review, we aimed to clarify the optimum extent of lymph node dissection in patients with cT1 and cT2 colorectal cancer.

METHODS

We reviewed medical records of 487 patients with cT1 and 351 patients with cT2 colorectal tumors, who had undergone curative surgery.

RESULTS

In patients with cT1 tumors, results of pathologic examination showed either no lymph node metastasis or metastasis within the paracolic or pararectal region in 284 (98.3 percent) of 289 patients with colon tumors and 195 (98.5 percent) of 198 with rectal tumors. Of 459 patients without clinically evident metastasis, only one patient with a poorly differentiated adenocarcinoma had metastasis beyond the paracolic area. In 28 patients with cT1 tumors and clinically diagnosed node metastasis, pathologic examination showed that node involvement did not extend beyond the named vessel in 26. Among patients with cT2tumors, 97.5 percent of patients with colon tumors and 95.9 percent with rectal tumors had no or limited metastasis. Of 276 without clinically evident metastasis, none had node metastasis at the roots of the named vessels; of 75 with clinically evident metastasis, none had pathologic extension beyond the roots of the named vessels.

CONCLUSIONS

In cT1 patients with cN-negative colorectal cancers, paracolorectal lymph node dissection may be optimal; in those with cN positivity, the regional nodes along the named vessels should be dissected. In cT2 patients who are cN-negative, dissection of the regional nodes may be optimal. For those with cN positivity, dissection at the roots of the named vessels should be considered.

The sentinel node concept in adenocarcinomas of the distal esophagus and gastroesophageal junction

OBJECTIVE

The sentinel node concept is of great value in the treatment of various malignancies. In this study we investigated whether the application of the sentinel node procedure is feasible in esophageal adenocarcinoma and whether it can tailor surgical treatment of the individual patient.

METHODS

In 40 patients with an adenocarcinoma of the distal esophagus or gastroesophageal junction, blue dye was injected around the tumor intraoperatively. Sentinel nodes (blue-stained) and nonsentinel nodes were identified and dissected during transhiatal esophagectomy. In sentinel nodes negative for tumor cells on routine hematoxylin-eosin examination, multilevel sectioning and immunohistochemical staining were performed to search for micrometastases.

RESULTS

The sentinel node procedure was technically successful in 39 of 40 patients (98%). The median number of sentinel nodes identified was 4. Sentinel nodes were present in more than 1 nodal station in 8 patients (21%). In 6 patients in whom the sentinel node was negative for metastasis, nonsentinel nodes were positive for tumor cells (false-negative rate 6/39 = 15%). Micrometastases and isolated tumor cells were detected in 7 of 19 patients (37%) with sentinel nodes, but this finding did not affect the false-negative rate.

CONCLUSION

Detection of sentinel nodes is technically feasible during esophagectomy for cancer. However, given the relatively high false-negative rate of 15% and the high frequency of sentinel nodes in more than 1 nodal station, the clinical relevance of the sentinel node concept (through application of the blue dye technique) in the current treatment of patients with an adenocarcinoma of the distal esophagus or gastroesophageal junction seems limited.

Clinical efficacy and problems with CT lymphography in identifying the sentinel node in breast cancer

BACKGROUND

Combining a radioisotope with a dye-guided method is the best method for identification of the sentinel lymph nodes (SNs) in breast cancer. However, some institutions are limited to use of a dye-guided method alone. Recently, computed tomographic lymphography (CTLG) employing a nonionic contrast medium has achieved SN identification.

PATIENTS AND METHODS

218 patients with primary breast cancer and no clinical evidence of lymph node metastasis were studied. SN identification was performed by CTLG and a dye-guided method. The SN identification rate was analyzed for correlations with the clinicopathological findings.

RESULTS

The SN identification rates were 96% with CTLG, 92% with the dye-guided method and 99% with both methods combined. The identification rates with CTLG and the combined method were significantly lower in node-positive patients compared to node-negative patients, and significantly lower with the combined method in vascular invasion-positive patients compared to negative patients. In addition, the SN identification rate with the dye-guided method was significantly lower in patients with a body mass index (BMI) of > or = 25, whereas the BMI did not affect the identification rate with CTLG or the combined method. Multiple SNs were detected in approximately 20% of the patients.

CONCLUSION

Combined performance of CTLG and a dye-guided method enables identification of SNs prior to breast cancer surgery. That SN identification is easier compared with by the dye-guided method alone, and the identification rate is improved compared with either method alone. The combination of methods was especially useful in obese patients. For patients with multiple SNs, the combination has the further advantage of enabling accurate SN biopsy. CTLG may yield false-negative findings in node-positive patients and patients with lymph vessel obstruction.