Sentinel Lymph Node In Colorectal Cancer Research Articles

Sensitivity and specificity of indocyanine green near-infrared fluorescence imaging in detection of metastatic lymph nodes in colorectal cancer: Systematic review and meta-analysis.

This review aimed to determine the overall sensitivity and specificity of indocyanine green (ICG) near-infrared (NIR) fluorescence in sentinel lymph node (SLN) detection in Colorectal cancer (CRC). A systematic search in electronic databases was conducted. Twelve studies including 248 patients were reviewed. The median sensitivity, specificity, and accuracy rates were 73.7, 100, and 75.7. The pooled sensitivity and specificity rates were 71% and 84.6%. In conclusion, ICG-NIR fluorescence is a promising technique for detecting SLNs in CRC.

The Significance of the Sentinel Lymph Node in Colorectal Cancer and its Isolation with Radioactive Colloid-A Pilot Study

AbstractIntroduction.One of the most important factors for prognosis in patients with colorectal cancer (CRC), especially the 5-year survival is the status of regional lymph nodes (RLN). Threfore, today’s recommendations for systematic lymphadenectomy in CRC operations are very important. For correct staging and accepted by all international recommendations, at least 12 LN must be analyzed microscopically. The sentinel lymph node (SLN) is the first lymph node that drains lymph from the tumor and thus represents a LN that has the greatest chance to be the bearer of metastatic disease. Tests to locate the SLN in CRC have started recently and so far there is no consensus on the method for its localization or its significance. The main aim of this study was to improve the tracing of SLN by using radioactive colloid. The secondary aims were to investigate the accuracy, sensitivity and rate of method’s identification. Especially important for the analysis is the significance of SLN and its correlation with other RLN.Methods.The study is performed at the University Clinic for Digestive Surgery from January 2013 and is still ongoing. A day before the surgery endoscopically around the tumor is injected radioactive colloid with Technetium 99 (Sentiscint Tc 99m Mediradiofarma Ltd) in the amount of 4 ml, which corresponds to 4 mCi (mill curie). Immediately after that, at the Institute of Pathophysiology using a Gamma camera (Mediso DHV nucline spirit), the distribution of the colloid is monitored, which as expected is mostly accumulated in the first LN, that is the genuine sentinel lymph node, thus making lymphatic mapping that is important for identifying possible aberrant drainage. On the day of surgery at 8:00 am, a rerecording with the Gamma camera is made that shows the late distribution of contrast. All patients are operated with standard surgical technique by making resection with systematic lymphadenectomy. Promptly after removing the preparation a Gamma detector probe (Europrobe) is used to determine the radioactivity of the lymph pool and it finds the right SLN which has the highest radioactivity and it is separately sent for complete pathohistological analysis. At the Institute of Pathology all lymph nodes are first treated standardly with HE and then with immunohistochemical method.Results.So far the study includes 10 patients, 6 men and 4 women, mean age 63 years (59-77). Until now the identification rate is 100%, which means that SLN has been found in all procedures. Only in 2 patients two sentinel lymph nodes have been revealed while the in the remaining only 1, average 1.2. At PH analysis, an average of 14.2 lymph nodes have been isolated (6-25). Only in one patient false negative 1 SLN has been revealed. The number of patients with real negative SLN is 2, which means the SLN is negative and also all the other lymph nodes. The total number of patients with real positive SLN is 7, which means SLN is positive and also some of the other lymph nodes. Therefore the accuracy of the procedure is 90%. The sensitivity of the procedure in our study that is still ongoing, is 87.5%. Up to now there have been no micrometastases detected in these 10 patients with immunohistochemical methods and because of it the up staging for now is 0%. In 2 patients the SLN is the only positive lymph node of all examined LN. In none of the patients aberrant lymphatic drainage has been discovered.Conclusions.From the results obtained so far in this study, it can be concluded that the identification of the SLN with this method is possible; the accuracy and sensitivity are high and we expect them to be even higher, which is our motive to continue with the study and to analyze minimum 30 patients. We think this would be the highest number of discovered SLN by a surgeon and an institution and we believe it to be sufficient validation of the method.

Quantitative Analysis of Superparamagnetic Contrast Agent in Sentinel Lymph Nodes Using Ex Vivo Vibrating Sample Magnetometry

As the first step in developing a new clinical technique for the magnetic detection of colorectal sentinel lymph nodes (SLNs), a method is developed to measure the magnetic content in intact, formalin fixated lymph nodes using a vibrating sample magnetometer (VSM). A suspension of superparamagnetic nanoparticles is injected ex vivo around the tumor in the resected colon segments. A selection of three lymph nodes is excised from the region around the tumor and is separately measured in the VSM. The iron content in the lymph nodes is quantified from the magnetic moment curve using the Langevin model for superparamagnetism and a bimodal particle size distribution. Adverse, parasitic movements of the sample were successfully reduced by tight fixation of the soft tissue and using a small vibration amplitude. Iron content in the lymph nodes is detected with 0.5 μg accuracy and ranged from 1 to 51 μg. Histological staining confirmed iron presence. The current method of measuring intact biological tissue in a VSM is suitable to show the feasibility and merit of magnetic detection of SLNs in colorectal cancer. For clinical validation of magnetic SLN selection in colorectal cancer, a new magnetometer with high specificity for superparamagnetic nanoparticles is required.

Sentinel lymph node mapping with GI cancer

Precise evaluation of lymph node status is one of the most important factors in determining clinical outcome in treating gastro-intestinal (GI) cancer. Sentinel lymph node (SLN) mapping clearly has become highly feasible and accurate in staging GI cancer. The lunchtime symposium focused on the present status of SLN mapping for GI cancer. Dr. Kitigawa proposed a new strategy using sentinel node biopsy for esophageal cancer patients with clinically early stage disease. Dr. Uenosono reported on whether the SLN concept is applicable for gastric cancer through his analysis of more than 180 patients with cT1-2, N0 tumors. The detection rate was 95%, the false negative rate of lymph node metastasis including micro-metastasis was 4%, and accuracy was 99% in gastric cancer patients with cT1N0. Dr. Bilchik recommended the best technique for identifying SLNs in colorectal cancer: a combination of radiotracer and blue dye method, emphasizing that this technique will become increasingly popular because of the SLN concept, with improvement in staging accuracy. He stressed that this novel procedure offers the potential for significant upstaging of GI cancer. Dr. Saha emphasized that SLN mapping for colorectal cancer is highly successful and accurate in predicting the presence or absence of nodal disease with a relatively low incidence of skip metastases. It provided the "right nodes" to the pathologists for detailed analysis for appropriate staging and treatment with adjuvant chemotherapy. Although more evidence from large-scale multicenter clinical trials is required, SLN mapping may be very useful for individualizing multi-modal treatment for esophageal cancer and might be widely acceptable even for GI cancer.

Sentinel lymph node evaluation is technically feasible and may improve staging in colorectal cancer

PURPOSE: The accurate nodal staging of colorectal cancer (CRC) is important to identify those patients who may benefit from adjuvant chemotherapy. Some have suggested that identification of sentinel lymph nodes (SLN) may improve staging in CRC. We sought to determine: the feasibility of identifying SLN in CRC utilizing isosulfan blue dye; the accuracy of the identified SLN in predicting the status of the remainder of the lymph nodes in CRC; and whether a more thorough evaluation of SLN with serial step sectioning and immunohistochemistry would more accurately stage patients with CRC. METHODS: A pilot trial was initiated at Walter Reed Army Medical Center (WRAMC), and 17 patients with masses on colonoscopy and subsequent tissue diagnosis of CRC were enrolled. Patients underwent standard surgical resection of their CRC with wedge of mesentery containing draining lymph nodes. Isosulfan blue dye was injected around the tumor subserosally/submucosally before dividing the mesenteric portion of the resection (n = 7) or ex vivo (n = 10). Sentinel lymph nodes were defined as all nodes staining blue and were dissected from the mesentery in the operating room. The SLN were sent separately for standard bivalving and hematoxylin and eosin staining (H&E) followed by serial step sectioning and immunohistochemistry (IHC) staining for cytokeratin. RESULTS: Seventeen patients (6 men, 11 women) were enrolled. The average preoperative carcinoembryonic antigen (CEA) was 5.9 (range, 1.2 to 18.9), and the average postoperative CEA was 2.8 (range, 0.7 to 9.1). One patient had a T1 tumor, 6 patients had T2 tumors, and 10 patients had T3 tumors on final pathology. Five cancers were well differentiated, 11 were moderately differentiated, and 1 was poorly differentiated. In all 17 cases, SLN were identified. A mean of 5.5 SLN was found per specimen (range, 2 to 11) with no difference noted between injection techniques (in vivo vs ex vivo). An additional 12 nonsentinel lymph nodes (range, 1 to 29) were identified per specimen. Ten patients had negative SLN and non-SLN. Seven patients were found to have positive SLN (3 by H&E, 2 by serial step sectioning, and 2 by IHC only). CONCLUSIONS: The isosulfan blue technique is technically feasible to allow identification of sentinel lymph nodes. In this study, no false-negative SLN occurred. A total of 7 patients had positive SLN; more importantly, 4 patients were upstaged as a result of serial step sectioning and immunohistochemistry staining. We hypothesize that this method may help pathologists find appropriate lymph nodes for more detailed analysis. As a result, patients may be more accurately staged and counseled for adjuvant chemotherapy, which has been shown to improve survival in node-positive CRC. Further studies should be undertaken to test these preliminary findings.

Technical details of sentinel lymph node mapping in colorectal cancer and its impact on staging.

Sentinel lymph node (SLN) mapping for melanoma and breast cancer has greatly enhanced the identification of micrometastases in many patients, thereby upstaging a subset of these patients. The purpose of this study was to see if SLN mapping technique could be used to identify SLNs in colorectal cancer and to assess its impact on pathological staging and treatment. At the time of surgery, 1 ml of Lymphazurin 1% was injected subserosally around the tumor without injecting into the lumen. The first to fourth blue nodes identified were considered the SLNs, which have the highest probability to contain metastases. A standard oncological resection of the bowel was then performed. Multilevel microsections of the SLNs, including a detailed pathological examination of the entire specimen, was performed. SLN was successfully identified in 85 (98.8%) of 86 patients. In 85 patients, there were 1,367 (16 per patient) lymph nodes examined, of which 140 (1.6 per patient) were identified as SLNs. In 53 (95%) of 56, of whom the SLNs were without metastases (negative), all other non-SLNs also were negative. In 29 (34% of 85) patients, SLNs were positive for metastases; in 14 of the 29 patients, other non-SLNs also were positive in addition to the SLNs. In the other 15 of the 29 patients (18% of 85 patients), SLNs were the only site of metastases, and all other non-SLNs were negative. In 7 patients (8.2% of 85 patients), micrometastases were identified only in 1 or 2 of the 10 sections of a single SLN. In five of seven patients, such micrometastases were detected by hematoxylin and eosin staining and immunohistochemistry; in the other two patients, it was detected only by immunohistochemistry. In patients with negative SLNs, the rate of occurrence of micrometastases in non-SLNs was 5 (0.4%) of 1,184 lymph nodes. SLN mapping can be performed easily in colorectal cancer patients, with an accuracy of more than 95%. The identification of submicroscopic lymph node metastases by this technique may have upstaged these patients (18%) from stage I/II to stage III disease, who may then benefit from further adjuvant chemotherapy.