Accuracy of sentinel node biopsy in esophageal carcinoma: a systematic review and meta-analysis of the pertinent literature. Surg Today. 2014;44:607-619. [PMID: 23715926 DOI: 10.1007/s00595-013-0590-9]

Sentinel Lymph Node Techniques in Urologic Oncology: Current Knowledge and Application

Lymph node (LN) metastases have a significant negative impact on the prognosis of urological malignancies. Unfortunately, current imaging modalities are insufficient when it comes to detecting micrometastases; thus, surgical LN removal is commonly used. However, there is still no established ideal lymph node dissection (LND) template, leading to unnecessary invasive staging and the possibility of missing LN metastases located outside the standard template. To address this issue, the sentinel lymph node (SLN) concept has been proposed. This technique involves identifying and removing the first group of draining LNs, which can accurately stage cancer. While successful in breast cancer and melanoma, the SLN technique in urologic oncology is still considered experimental due to high false-negative rates and lack of data in prostate, bladder, and kidney cancer. Nevertheless, the development of new tracers, imaging modalities, and surgical techniques may improve the potential of the SLN procedures in urological oncology. In this review, we aim to discuss the current knowledge and future contributions of the SLN procedure in the management of urological malignancies.

Diagnostic Value of the Sentinel Lymph Node Technique in Patients with Muscle-Invasive Bladder Cancer

BACKGROUND

The optimal limits of the bilateral pelvic lymph node dissection (PLND) template in bladder cancer treatment remain controversial. This study aimed to investigate whether radio-guided sentinel node (SLN) detection is a reliable technique for the perioperative localisation of potential lymphatic metastasis during cystectomy for muscle-invasive bladder cancer (MIBC).

MATERIALS AND METHODS

We studied 54 patients with pT2-pT4 MIBC who underwent cystectomy with extended PLND (ePLND) augmented by the SLN technique. The identification of SLN was performed by preoperative SPECT/CT hybrid lymphoscintigraphy using peritumoral injection of nanocolloid-Tc-99m, followed by intraoperative navigation with a handheld γ-probe. All nodal specimens were collected separately and then fixed in formalin, stained with haematoxylin and eosin, and examined by an experienced uropathologist.

RESULTS

A total of 1414 LNs were resected and examined for the presence of metastases. The mean number of harvested LNs was 26 (range: 11-50) per patient. In 51 of 54 patients, 192 SLNs were resected. In addition, 20/192 (10.4%) SLNs were located outside of the ePLND area. Overall, 72 metastatic LNs (LN+) were found in 22 of 54 patients (40.7%) and in 24/192 SLNs (12.5%). The SLN technique detected LN+ in 14 of 22 (64%) patients. The SLNs were the only sites of metastasis (SLN+ = LN+) in 6 of 22 (27.3%) LN+ patients, including two cases with foci located in the pararectal region. The diagnostic values for the sensitivity, specificity, positive predictive value, and false-negative rate for the SLN technique were 66.66%, 4.16%, 28.57%, and 33.33%, respectively. Extended lymphadenectomy and its combination with the SLN technique enabled the correct assessment in 96.3 and 100% of patients, respectively.

CONCLUSIONS

The combination of ePLND and SLN provides a better pN assessment compared to ePLND alone. Although the SLN technique has restrictions that limit its diagnostic value, its use as an addition to lymphadenectomy allows for the visualisation of nonstandard lymph drainage pathways that may be potential metastatic routes.

Sentinel lymph node mapping in breast cancer patients following neoadjuvant chemotherapy: systematic review and meta-analysis about head to head comparison of cN0 and cN + patients

PURPOSE

The effectiveness of sentinel lymph node (SLN) mapping and biopsy following neoadjuvant chemotherapy (NAC) in axillary lymph node staging of breast cancer (BCa) patients with initial clinical node positive status (cN +) compared to clinical node negative status (cN0) is not yet known. The aim of this meta-analysis was to compare the accuracy of SLN mapping following NAC in cN + and cN0 BCa patients.

METHODS

PubMed and Scopus were comprehensively reviewed to retrieve all the studies that performed SLN mapping/biopsy and standard axillary lymph node dissection on cN0 and cN + BCa patients following NAC. Pooled detection and false negative rates for N0 and N + patients including 95% confidence interval values (95% CI) were evaluated. Odds ratio (OR) and risk difference (RD) of SLN detection failure and false negative results were compared between two groups.

RESULTS

A total of 27 articles were included for SLN detection rate evaluation and 17 for false negative assessment. The OR and RD of detection failure in N + group compared with N0 group following NAC were 2.22 (p = 0.00, 95% CI 1.4-3.4) and 4% (p = 0.00, 95% CI 2-6%), respectively. The OR and RD of false negative rate were 1.6 (p = 0.01, 95% CI 1-2.6) and 8% (p = 0.02, 95% CI 1-14%), respectively.

CONCLUSION

SLN mapping in BCa patients following NAC shows high risk of detection failure and high false negative rate of SLN biopsy in cN + patients. In comparison with cN0 BCa patients, SLN mapping and biopsy after NAC was associated with almost two times higher odds of detection failure and false negative results in cN + patients; therefore, this method should not be recommended in this group of patients.

Preoperative detection of sentinel lymph nodes with hybrid SPECT/computed tomography imaging may improve the accuracy of sentinel lymph node biopsies in patients with early stages of cancer of the oesophagus or gastro-oesophageal junction

Objectives

The aim of this study was to investigate the sentinel lymph node biopsy (SLNB) method in patients with cancer of the oesophagus or gastro-oesophageal junction (GOJ) guided by preoperative hybrid single-photon emission tomography/computed tomography (SPECT/CT) lymphoscintigraphy.

Methods

Thirty-nine patients with stage T1–T3, any N-stage, M0 cancer of the oesophagus or GOJ planned for curatively intended esophagectomy underwent preoperative SPECT/CT lymphoscintigraphy following endoscopically guided submucosal injection of radiocolloid and intraoperative radio-guided SLNB using a hand-held gamma scintillation device.

Results

The detection rate in preoperative SPECT/CT imaging was 88%. The median number of detected SLN stations in preoperative imaging was 1 (range 0–4). At least one suspected SLN was identified in all intraoperative SLNP procedures. In six cases, no lymph nodes were identified in the SLNB. In six cases, the SLNB was false negative. The sensitivity for successful SLNB procedures was 20%, the specificity was 100% and the accuracy was 75%.

Conclusions

Preoperative SLN mapping using SPECT/CT yields a high number of detected SLN stations compared to previous studies using planar imaging. The accuracy of the SLNB method in patients with predominantly ≥T3-stage tumours and with a history of previous neoadjuvant treatment is poor, and the method is not recommended in these patient groups.

Feasibility of sentinel node navigated surgery in high-risk T1b esophageal adenocarcinoma patients using a hybrid tracer of technetium-99 m and indocyanine green

BACKGROUND

Minimally invasive esophagectomy with two-field lymphadenectomy is standard of care for T1b esophageal adenocarcinoma (EAC) with a high risk of lymph node metastasis. Sentinel node navigation surgery (SNNS) is a well-known concept to tailor the extent of lymphadenectomy. The aim of this study was to evaluate the feasibility and safety of SNNS with a hybrid tracer (technetium-99 m/indocyanine green/nanocolloid) for patients with high-risk T1b EAC.

METHODS

In this prospective, multicenter pilot study, 5 patients with high-risk T1b EAC were included. The tracer was injected endoscopically around the endoscopic resection scar the day before surgery, followed by preoperative imaging (lymphoscintigraphy/SPECT-CT). During surgery, first the SNs were localized and resected based on preoperative imaging and intraoperative gammaprobe- and fluorescence-based detection, followed by esophagectomy. Primary endpoints were the percentage of patients with detectable SNs, concordance between preoperative and intraoperative SN detection, and the additive value of indocyanine green.

RESULTS

SNs could be identified and resected in all patients (median 3 SNs per patient, range 2-7). There was a high concordance between preoperative and intraoperative SN detection. In 2 patients additional peritumoral SNs were identified with fluorescence-based detection. None of the resected lymph nodes showed signs of (micro)metastases and no nodal metastases were detected in the surgical resection specimen.

CONCLUSIONS

SNNS using technetium-99 m/indocyanine green/nanocolloid seems feasible and safe in patients with high-risk T1b EAC. Indocyanine green fluorescence seems to be of additive value for detection of peritumoral SNs. Whether this approach can optimize selection for esophagectomy needs to be studied in future research.

Performance of Indocyanine-Green Imaging for Sentinel Lymph Node Mapping and Lymph Node Metastasis in Esophageal Cancer: Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Lymphatic mapping with indocyanine-green (ICG) and near-infrared light fluorescent imaging is widely used for sentinel lymph node staging in different types of cancer but is not fully accepted for all procedures because studies have reported heterogeneous results. This study aimed to assess the detection rate (DR) of ICG imaging for sentinel lymph node mapping (SLNM) and lymph node metastases (LNMs) in esophageal cancer.

METHODS

A systematic search was performed to identify relevant studies examining the use of ICG imaging for SLNM in patients with esophageal cancer. Extracted results were pooled in a single-proportion meta-analysis, with a random-effects model, presented as forest plots.

RESULTS

Six studies were included in the analysis. The ICG DR for SLNM was 89% [95% confidence interval (CI) 71%-96%]. The pooled sensitivity and specificity values for the detection of LNMs were 84% (95% CI 64%-94%) and 15% (95% CI 3%-45%), respectively. A trend towards a lower DR was found with increasing mean latency time between ICG injection and SLNM.

CONCLUSIONS

ICG imaging is a technique that potentially could improve lymph node yield excision and, as a consequence, improve the detection of lymph node metastases.

Finding the "True" N0 Cohort: Technical Aspects of Near-infrared Sentinel Lymph Node Mapping in Non-small Cell Lung Cancer

OBJECTIVE

To examine technical-, patient-, tumor-, and treatment-related factors associated with NIR guided SLN identification.

BACKGROUND

Missed nodal disease correlates with recurrence in early stage NSCLC. NIR-guided SLN mapping may improve staging and outcomes through identification of occult nodal disease.

METHODS

Retrospective analysis of 2 phase I clinical trials investigating NIR-guided SLN mapping utilizing ICG in patients with surgically resectable NSCLC.

RESULTS

In total, 66 patients underwent NIR-guided SLN mapping and lymphadenectomy after peritumoral ICG injection. There was significantly increased likelihood of SLN identification with injection dose ≥1 mg compared to <1 mg (65.2% vs 35.0%, P = 0.05), lung ventilation after injection (65.2% vs 35.0%, P = 0.05), and albumin dissolvent (68.1%) compared to fresh frozen plasma (28.6%) and sterile water (20.0%) (P = 0.01). In patients receiving the optimized ICG injection, there was significantly increased likelihood of SLN identification with radiologically solid nodules compared to sub-solid nodules (77.4% vs 33.3%, P = 0.04) and anatomic resection compared to wedge resection (88.2% vs 52.2%, P = 0.04). Disease-free and overall survival are 100% in those with a histologically negative SLN identified (n = 25) compared to 73.6% (P = 0.02) and 63.6% (P = 0.01) in patients with node negative NSCLC established via routine lymphadenectomy alone (n = 22).

CONCLUSIONS

SLN(s) are more reliably identified with ICG dose ≥1 mg, albumin dissolvent, post-injection lung ventilation, radiologically solid nodules, and anatomic resections. To date, N0 status when established via NIR SLN mapping seems to be associated with decreased recurrence and improved survival after surgery for NSCLC.

Sentinel lymph node biopsy in muscle-invasive bladder cancer: single-center experience

OBJECTIVE

In this study, the validity of sentinel node biopsy procedure as our index test was assessed and compared with bilateral pelvic lymphadenectomy for staging and detecting the regional lymph nodes metastasis in patients with muscle-invasive bladder cancer (MIBC).

METHODS

Consecutive series of cases with T1-T4 urothelial MIBC were included. Following the injection of radiotracer, sentinel nodes were sought using a handheld gamma probe and all hot nodes were harvested. Bilateral pelvic lymphadenectomy was done for all patients following sentinel node biopsy. The tumor specimen, sentinel nodes, and excised lymph nodes were evaluated histopathologically. Same as the other midline tumors, detection rate and false negative rates were calculated using patient basis and side basis methods.

RESULTS

By evaluating each patient as a unit of analysis, sentinel nodes were detected in 35 of 41 patients (85%), 13/16 (81%) of the neoadjuvant chemotherapy (NAC) and 22/25 (88%) of the no-neoadjuvant chemotherapy (No-NAC) participants. The false negative rate was 3/7 (42%): 1/3 (33%) for NAC, and 2/4 (50%) for No-NAC patients. By evaluating each hemipelvis as a unit of analysis, sentinel nodes were detected in 53 of 82 hemipelves (65%), 19/32 (66%) of the NAC, and 34/50 (68%) of the No-NAC hemipelves. No false-negative result was found by assessing each hemipelvis as a unit of analysis.

CONCLUSIONS

Sentinel node biopsy is a feasible method for lymph node staging in MIBC, including patients with a history of NAC. To optimize the sensitivity, the decision regarding the lymphadenectomy is best to be based on the pathological status of sentinel node harvested from each hemipelvis separately as the unilateral finding of a sentinel node, does not rule out the possibility of metastatic involvement of contralateral pelvic lymph nodes.

Sentinel node navigation surgery in esophageal cancer

Over the last 20 years, the sentinel node (SN) concept has been widely applied to the surgical staging of both breast cancer and melanoma. However, the validity of this concept has been controversial for esophageal cancer, because SN mapping for esophageal cancer is not considered to be technically easy because of the complicated multidirectional lymphatic networks of the esophagus and mediastinum. Nevertheless, studies including meta-analyses indicated that SN mapping may be feasible in early esophageal cancer. Transthoracic esophagectomy with three-field lymphadenectomy was developed as a potential curative procedure for thoracic esophageal cancer. However, this highly invasive procedure might increase morbidity and reduce patients' quality of life (QOL) after esophagectomy. Although further validation based on multicenter trials using the standard protocol of SN mapping for esophageal cancer is required, SN navigation surgery would enable us to carry out personalized and limited lymph node dissection which might reduce morbidity and maintain patients' QOL.

"Sentinel lymph node imaging with sequential SPECT/CT lymphoscintigraphy before and after neoadjuvant chemoradiotherapy in patients with cancer of the oesophagus or gastro-oesophageal junction - a pilot study"

BACKGROUND

In current best practise, curatively intended treatment for oesophageal cancer usually consists of neoadjuvant chemo-radiotherapy (nCRT) or perioperative chemotherapy, and oesophagectomy. Sentinel Lymph Node Biopsy (SLNB) has the potential to identify patients without lymph node metastases and thus improve the staging accuracy and influence treatment. The impact of neoadjuvant treatment on the lymphatic drainage of oesophageal cancers and subsequently the SLNB procedure in this tumour type has previously not been well studied.

PURPOSE

To evaluate changes in lymphatic drainage patterns of the tumour in patients with cancer of the oesophagus or gastro-oesophageal junction (GOJ) using Sentinel Lymph Node (SLN) hybrid SPECT/CT lymphoscintigraphy before and after nCRT.

METHODS

Patients with clinical stage T2-T3, any N-stage, M0 cancer of the oesophagus or GOJ underwent endoscopically guided peri-/intratumoral injection of radio-colloid followed by hybrid SPECT/CT lymphoscintigraphy prior to, and once again following, nCRT. SPECT/CT images were evaluated to number and location of SLNs and compared between the two examinations.

RESULTS

Ten patients were included in this pilot trial. SPECT/CT lymphoscintigraphy was performed in twenty procedures. The same Sentinel Lymph Node station before and after nCRT was observed in one single patient. In two patients, no SLN was detected before nCRT. In three patients no SLN was detected following nCRT. In four patients, the SLN stations were not the same station at baseline compared to follow-up examination.

CONCLUSIONS

The reproducibility SLN detection in patients with cancer of the oesophagus/GOJ following nCRT was very poor. nCRT appears to alter lymphatic drainage patterns and thus may affect detection of SLNs and potentially also the accuracy of an SLNB in these patients. On the basis of these initial results, we abort further patient recruitment in our institution.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR). Identifier ACTRN12618001433291 . Date registered: 27/08/2018. Retrospectively registered.

Pilot-study on the feasibility of sentinel node navigation surgery in combination with thoracolaparoscopic lymphadenectomy without esophagectomy in early esophageal adenocarcinoma patients

High-risk submucosal esophageal adenocarcinoma's might be treated curatively by means of radical endoscopic resection, followed by thoracolaparoscopic lymphadenectomy without concomitant esophagectomy. A preclinical study has shown the feasibility and safety of this approach; however, no studies are performed in a clinical setting. In addition, sentinel node navigation surgery could be valuable in tailoring the extent of the lymphadenectomy. This study aimed to evaluate the feasibility and safety of thoracolaparoscopic lymphadenectomy without esophagectomy (phase I) and sentinel node navigation surgery (phase II) in patients with early esophageal adenocarcinoma. Patients with T1N0M0 early esophageal adenocarcinoma scheduled for esophagectomy without neoadjuvant therapy were included. Phase I: Two-field, esophagus preserving, thoracolaparoscopic lymphadenectomy was performed, followed by esophagectomy in the same session. Primary outcome parameters were the number of lymph nodes resected, and number of retained lymph nodes in the esophagectomy specimen. Phase II: A radioactive tracer was injected endoscopically the day before surgery. Static imaging was performed 15 and 120 minutes after injection. The day of surgery, sentinel node navigation surgery followed by esophagectomy was performed. Primary outcome parameters were the percentage of patients with a detectable sentinel node, and the concordance between static imaging and probe-based detection of sentinel node. Phase I: Five patients were included, and a median of 30 (IQR: 25-46) lymph nodes was resected. A median of 6 (IQR: 2-9) retained lymph nodes was found in the esophagectomy specimen. No acute adverse events occurred, but near the end of lymphadenectomy esophageal discoloration was observed, possibly indicating ischemia. Phase II: In all five included patients sentinel nodes could be visualized and resected, at a median of 3 (IQR: 2-5) locations. There was a high concordance between imaging and probe-based detection of sentinel nodes. In conclusion, sentinel node navigation surgery followed by lymphadenectomy without concomitant esophagectomy seems feasible in patients with high-risk submucosal early esophageal adenocarcinoma. More evidence is however needed before applying this technique in clinical practice.

The extent of lymphadenectomy in esophageal resection for cancer should be standardized

The incidence of esophageal cancer increases, with approximately 482,000 patients diagnosed with esophageal cancer each year. Despite the growing incidence of esophageal carcinoma, the extent of the lymphadenectomy is still under discussion. Lymph node status is an important prognostic parameter in esophageal cancer and an independent predictor of survival. Surgical strategy depends on the distribution pattern of nodal metastases but consensus on the extent of lymphadenectomy differs worldwide. For squamous cell cancer, Japanese surgeons have standardized the 2- or 3-field lymphadenectomy according to the location of the tumor. For adenocarcinoma, in the Western World accounting for 85% of all esophageal cancers, the type of lymphadenectomy to perform is not clear. Moreover, the use of neoadjuvant therapy may influence the mediastinal lymph nodes and the significance of the lymphadenectomy for survival. These aspects have challenged the traditional policy concerning lymphadenectomy, at least in the Western World. Furthermore, an extensive lymphadenectomy may improve survival but, on the other hand, may cause significant more morbidity. An overview of the literature on the extent of lymphadenectomy for esophageal cancer with respect to the supposed lymph node distribution patterns for squamous cell carcinoma and adenocarcinoma, the different lymph node classification systems, the commonly used surgical techniques and outcomes, and the proposal of observational cohort study to standardize the type of lymphadenectomy according to the type of tumor, location and use of neoadjuvant therapy will be provided.

The Prevalence of Overall and Initial Lymph Node Metastases in Clinical T1N0 Thoracic Esophageal Cancer: From the Results of JCOG0502, a Prospective Multicenter Study

OBJECTIVE

To evaluate the sites and frequencies of overall and initial lymph node (LN) metastases (LNMs) of clinical T1N0 esophageal cancer.

BACKGROUND

The sites and frequencies of initial LNMs and sentinel LNs (SLNs) of esophageal cancer remain unclear.

METHODS

The Japan Clinical Oncology Group JCOG0502 trial was a 4-arm prospective study that compared esophagectomy with chemoradiotherapy for clinical T1N0 esophageal cancer in both randomized and patient-preference arms. The preoperative diagnostic accuracy was evaluated for patients assigned to the surgery arm. Patients who withdrew consent and who were not treated were excluded. All patients underwent esophagectomy with D2 or greater LN dissection. From the pathologic findings, sites and frequencies of LNMs and SLNs were assessed and the frequency of skip LNMs was calculated.

RESULTS

In total, 211 patients underwent LNM and SLN analysis. Regarding N-factor accuracy, 57 (27.0%) of 211 clinical N0 cases had pathologic LNMs. The upper mediastinal and mediastinal/abdominal regions were frequent sites of LNMs in upper and lower thoracic cases, respectively. However, in middle thoracic cases, LNMs were observed in the neck, mediastinal, and abdominal regions, and pathologic SLN spread to all 3 fields. The frequency of skip LNMs was 36.7%.

CONCLUSIONS

A clinical diagnosis of T1N0 is not sufficiently accurate, and therefore, it is unacceptable to omit LN dissection or minimize the prophylactic radiation field. SLNs, which are not location restricted, should be surveyed in all 3 fields.

The epithelial-mesenchymal transition phenotype of metastatic lymph nodes impacts the prognosis of esophageal squamous cell carcinoma patients

Epithelial-mesenchymal transition (EMT) plays a key role in tumor metastasis, but the significance of EMT phenotype to the prognosis of esophageal squamous cell carcinoma (ESCC) patients remains unclear. We used immunohistochemistry to examine the expression of the EMT-related proteins E-cadherin, N-cadherin and vimentin in samples of T3N1-3M0 ESCC from 155 primary tumors (PTs) with paired metastatic lymph nodes (MLNs) and 58 PTs without paired MLNs. Based on the expression pattern of the EMT markers, PTs and MLNs were classified as EMT wild, hybrid, null or complete type. The hybrid (42.7%) and complete (39.4%) types predominated among PTs, whereas the wild (34.2%) and hybrid (52.9%) types predominated among MLNs, and EMT phenotypes differed between the paired PTs and MLNs (P < 0.001). Univariate analysis revealed that, for PTs, the EMT phenotype was associated with N-stage (P = 0.039) but not patient survival, and that patients with complete or hybrid type MLNs had better overall survival (OS, P = 0.001) and disease-free survival (DFS, P = 0.005) than patients with null and wild type MLNs, especially those with N1-stage disease (P = 0.017 for OS, and P = 0.017 for DFS, respectively). Multivariate analysis revealed that wild and null type MLNs as well as older age and N2-3 stage were independent predictors of OS and DFS (P < 0.05). Thus MLNs exhibit EMT phenotypes that are distinct from those of their PT and may serve as a novel independent prognostic indicator in ESCC.

Retrograde Lymphatic Spread of Esophageal Cancer: A Case Report

The concept of the retrograde lymphatic spread of cancer cells appears to account for a subset of the essential mechanisms of cancer metastasis in various organs. However, no adequate data currently exist to illustrate the pathology of the retrograde lymphatic metastasis of cancer cells in human bodies. To shed light on this phenomenon, we report a case of a 63-year-old Japanese man who underwent an esophagectomy and lymph node dissection for early-stage esophageal cancer.The patient's clinical information was evaluated by board-certified surgeons and internists. Surgically excised materials were histopathologically evaluated by attending pathologists.Postoperative pathological examination revealed that the patient's tumor was a well-differentiated squamous cell carcinoma with negative surgical margins (T1N0M0, stage I). Apart from the primary lesion, a single lymphatic vessel invasion was found between the lamina propria and lamina muscularis of the esophagus where intralymphatic cancer cells had spread against the direction of backflow prevention valves and skipped beyond these valves without destroying them.The present case demonstrated that the retrograde lymphatic spread of cancer cells can occur in valve-equipped lymphatic vessels. Our study may not only provide a scientific basis for the concept of retrograde lymphatic metastasis but also explain a portion of the complexities associated with the lymphogenous metastasis of esophageal cancer.

Techniques that accurately identify the sentinel lymph node in cancer

Sentinel lymph node (SLN) biopsy has become the gold standard for patients with melanoma and breast cancer but it’s clinical application in other solid tumor types such as cancers of the esophagus, stomach, colon and rectum, head and neck, penis, uterine cervix and endometrium has been somewhat limited. Commonly used mapping techniques utilizing the combination of radiocolloid and blue dye may result in reduced SLN detection and increased false negative rates when applied to cancers with more complex lymphatic drainage patterns. Novel localization techniques including near infrared fluorescence, high resolution imaging and molecular targeted agents have been developed to address the limitations of conventional SLN detection practices in many solid tumor types. This article reviews the indications, techniques and detection rates for SLN biopsy in several different solid tumor types as well as the promising novel techniques created to address the contemporary limitations of this procedure.

Sentinel node biopsy for lymph nodal staging of uterine cervix cancer: a systematic review and meta-analysis of the pertinent literature

BACKGROUND

We reviewed the available literature on the accuracy of sentinel node mapping in the lymph nodal staging of uterine cervical cancers.

METHODS

MEDLINE and Scopus were searched by using "sentinel AND (cervix OR cervical)" as key words. Studies evaluating the accuracy of sentinel node mapping in the lymph nodal staging of uterine cervical cancers were included if enough data could be extracted for calculation of detection rate and/or sensitivity.

RESULTS

Sixty-seven studies were included in the systematic review. Pooled detection rate was 89.2% [95% CI: 86.3-91.6]. Pooled sensitivity was 90% [95% CI: 88-92]. Sentinel node detection rate and sensitivity were related to mapping method (blue dye, radiotracer, or both) and history of pre-operative neoadjuvant chemotherapy. Sensitivity was higher in patients with bilaterally detected pelvic sentinel nodes compared to those with unilateral sentinel nodes. Lymphatic mapping could identify sentinel nodes outside the routine lymphadenectomy limits.

CONCLUSION

Sentinel node mapping is an accurate method for the assessment of lymph nodal involvement in uterine cervical cancers. Selection of a population with small tumor size and lower stage will ensure the lowest false negative rate. Lymphatic mapping can also detect sentinel nodes outside of routine lymphadenectomy areas providing additional histological information which can improve the staging. Further studies are needed to explore the impact of sentinel node mapping in fertility sparing surgery and in patients with history of neoadjuvant chemotherapy.