Frozen section analysis and sentinel lymph node biopsy in well differentiated thyroid cancer

Sentinel lymph node detection in thyroid carcinoma using [68Ga]Ga-tilmanocept PET/CT: a proof-of-concept study

PURPOSE

Sentinel lymph node (SLN) biopsy is rarely used for thyroid carcinoma staging. This is due to challenges associated with conventional Tc-99m-labeled tracers, often producing a large hotspot at the injection site, potentially hiding nearby SLNs (shine-through effect). The aim of this study was to demonstrate the feasibility and effectiveness of SLN visualization using the new PET tracer [68Ga]Ga-tilmanocept.

METHODS

Patients with thyroid carcinoma underwent ultrasound-guided peritumoral injection of [68Ga]Ga-tilmanocept and ICG-[99mTc]Tc-nanocolloid. [68Ga]Ga-tilmanocept PET/CT scans were conducted at 15 min and 60 min post-injection to visualize the SLNs. SLN biopsy was performed using ICG-[99mTc]TC-nanocolloid for intraoperative identification. The corresponding lymph node level was resected for reference.

RESULTS

Seven differentiated thyroid carcinoma (DTC) and 3 medullary thyroid carcinoma (MTC) patients were included, of which 6 were clinically node-negative. The median number of SLNs detected on [68Ga]Ga-tilmanocept PET/CT and resected was 3 (range 1-4) and 3 (range 1-5), respectively. Eight SLNs were found on PET/CT in the central compartment and 19 in the lateral compartment. The SLN procedure detected (micro)metastases in all patients except one. Seventeen of 27 pathologically assessed SLNs were positive, 8 negative, and 2 did not contain lymph node tissue, which led to upstaging in 5 out of 6 clinically node-negative patients.

CONCLUSIONS

[68Ga]Ga-tilmanocept PET/CT identified SLNs in all patients, mainly in the lateral neck. The SLNs were successfully surgically detected and resected using ICG-[99mTc]Tc-nanocolloid. This technique has the potential to improve neck staging, enabling more personalized treatment of thyroid cancer according to the lymph node status.

TRIAL REGISTRATION

2021-002470-42 (EudraCT).

Sentinel lymph node mapping: current applications and future perspectives in thyroid carcinoma

Sentinel lymph node (SLN) mapping is a standard, minimally-invasive diagnostic method in the surgical treatment of many solid tumors, as for example melanoma and breast cancer, for detecting the presence of regional nodal metastases. A negative SLN accurately indicates the absence of metastases in the other regional lymph nodes (LN), thus avoiding unnecessary lymph nodal dissection. Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma (TC) with cervical LN metastases at diagnosis in 20-90%, and nodal involvement correlates with local persistence/recurrence. The SLN in PTC is an intraoperative method for staging preoperative N0 patients and for detecting metastatic LNs "in and outside" the cervical LN central compartment; it represents an alternative method to prophylactic central neck node dissection. In this review we summarize different methods and results of the use of SLN in TC. The SLN identification techniques currently used include the selective vital-dye (VD) method, 99mTc-nanocolloid planar lymphoscintigraphy with intraoperative use of a hand-held gamma probe (LS), the combination LS + VD, and the combination LS and preoperative SPECT-CT (LS + SPECT/CT). The application of the SLN procedure in TC has been described in many studies, however, the techniques are heterogeneous, and the role of SLN in TC, with indications, results, advantages and limits, is still debated.

Sentinel lymph node detection in thyroid carcinoma using 68Ga-tilmanocept PET/CT: a proof-of-concept study protocol

Sentinel lymph node biopsy (SLNB) is a diagnostic staging procedure. The procedure aims to identify the first draining lymph node(s), which are most likely to contain metastases. SLNB is applied in various cancers, but not currently in thyroid carcinoma. However, treatment strategies are changing, making SLNB clinically relevant. SLNB may lead to more accurate staging, prevent unnecessary treatment and help achieve earlier curation. 68Ga-tilmanocept PET/computed tomography (CT) can better localize sentinel lymph nodes (SLNs) near the primary tumor than planar scintigraphy and single-photon emission computed tomography (SPECT)/CT. This paper describes the rationale and design of a study investigating SLNB using 68Ga-tilmanocept PET/CT and indocyanine-green-99mTc-nanocolloid in ten differentiated and medullary thyroid carcinoma patients. Localization and number of SLNs, pathology result, optimal scan protocol, surgical time and surgeon's experience are examined. Clinical Trial Registration: 2021-002470-42 (EudraCT).

Validation of whole slide imaging for frozen section diagnosis of lymph node metastasis: A retrospective study from a tertiary care hospital in Thailand

BACKGROUND

The use of whole slide imaging (WSI) for frozen section (FS) diagnosis is helpful, particularly in the context of pathologist shortages. However, there is minimal data on such usage in resource-limited settings. This study aims to validate the use of WSI for FS diagnosis of lymph node metastasis using a low-cost virtual microscope scanner with consumer-grade laptops at a tertiary care hospital in Thailand.

METHODS

FS slides were retrieved for which the clinical query was to evaluate lymph node metastasis. They were digitized by a virtual microscope scanner (MoticEasyScan, Hong Kong) using up to 40× optical magnification. Three observers with different pathology experience levels diagnosed each slide, reviewing glass slides (GS) followed by digital slides (DS) after two weeks of a wash out period. WSI and GS diagnoses were compared. The time used for scanning and diagnosis of each slide was recorded.

RESULTS

295 FS slides were retrieved and digitized. The first-time successful scanning rate was 93.6 %. The mean scanning time was 2 min per slide. Both intraobserver agreement and interobserver agreement of WSI and GS diagnoses were high (Cohen's K; kappa value >0.84). The time used for DS diagnosis decreased as the observer's experience with WSI increased.

CONCLUSIONS

Despite varying pathological experiences, observers using WSI provided accurate FS diagnoses of lymph node metastasis. The time required for DS diagnoses decreased with additional observer's experience with WSI. Therefore, a WSI system containing low-cost scanners and consumer-grade laptops could be used for FS services in hospital laboratories lacking pathologists.

Clinical significance of sentinel lymph node biopsy in differentiated thyroid cancer

Differentiated thyroid cancers are the most common endocrine malignancy and include three main entities: papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), and Hürthle cell carcinoma (HCC). Papillary thyroid cancer (PTC) is the most common histologic subtype. Was to review different sentinel lymph node biopsy (SLNB) techniques in patients with differentiated thyroid cancer. We also will compare the detection rates and sensitivity of the different detection methods in these patients and assessment of feasibility and side effects of the different techniques. This study was a cross sectional study, Surgical Oncology Department of National Cancer Institute, Cairo University and Damietta Cancer Center, Ministry of Health and Population. Radionuclide technique (lymphoscintigraphy and gamma probe scanning) was successful in 94.6 % (35/37) of the patients as shown in table 4 and relation between SLN and identification by gamma probe. In the 37 patients, the intraoperative frozen biopsy indicated that 22 patients were experiencing SLN metastases, while post-operative routine pathological examination was able to diagnose three additional patients with lymph node metastases. 

Fine-needle aspiration biopsy versus frozen section examination in assessing cervical lymph node metastasis in primary clinically positive neck papillary thyroid carcinoma

BACKGROUND

Both fine-needle aspiration biopsy (FNAB) and frozen section (FS) examination are reliable methods for assessing cervical lymph node (level II-V) metastasis (LNM) in papillary thyroid carcinoma (PTC). Our goal was to compare the diagnostic accuracy of FNAB and FS in clinically positive neck (cN+) PTC patients.

METHODS

Altogether, 264 lymph node samples from 220 patients were prospectively enrolled. Samples were assessed by FNAB cytology (FNAB-C), thyroglobulin (Tg) FNAB needle wash testing (FNAB-Tg), and FS simultaneously. Diagnostic performance of the different methods were analyzed by the Chi-square test.

RESULTS

The sensitivity and specificity of FNAB-C alone in predicting LNM was 87.4% and 85.7%, respectively. Combined with FNAB-Tg, the sensitivity and specificity of FNAB-C increased to 98.9% and 81.6%, respectively. The sensitivity and specificity of FS in predicting LNM was 92.4% and 81.1%, respectively. FNAB-C and FNAB-Tg had better sensitivity than FS when applied to solid lymph nodes, and comparable sensitivity when applied to cystic and cystic-solid lymph nodes.

CONCLUSION

The utilization of FNAB-Tg significantly improved the diagnostic ability of FNAB-C. FS can be replaced by preoperative FNAB combined with FNAB-Tg without compromising diagnostic accuracy.

Feasibility of lateral sentinel lymph node biopsy in medullary thyroid cancer: A surrogate tool for determining prophylactic lateral neck dissection-A pilot study

BACKGROUNDS

This study aimed to evaluate usefulness of lateral sentinel lymph node biopsy (SLNB) in determining lateral neck dissection (LND) of patients with medullary thyroid cancer (MTC).

METHODS

Sixteen patients with MTC were enrolled in the study from January 2013 to June 2019. Intratumoral injection of technetium (Tc)-99m phytate followed by lymphoscintigraphy was performed preoperatively. Lateral sentinel lymph nodes were detected by a collimated gamma probe and underwent frozen analysis. Ipsilateral LND was performed in all patients to assess lateral LN status.

RESULTS

The identification rate of sentinel lymph nodes (SLNs) detected by radioisotope was 87.5% (14 of 16 patients). The sensitivity, specificity, positive predictive value, and negative predictive value of frozen analyses were 66.7%, 100%, 100%, and 91.6%, respectively. Based on final histopathology, however, the diagnostic values of lateral SLNB were all 100%.

CONCLUSIONS

This study showed that lateral SLNB can be a promising surgical tool for decisions on LND in patients with MTC.

The Diagnostic Accuracy of One-Step Nucleic Acid Amplification for Lymph Node Metastases of Papillary Thyroid Carcinoma： A Systematic Review and Meta-Analysis

BACKGROUND

One-step nucleic acid amplification (OSNA) analysis is a molecular diagnostic technique for lymph node metastases (LNMs) by quantifying cytokeratin 19(CK 19) mRNA. We aim to evaluate the intraoperative diagnostic accuracy of OSNA assay for LNMs of papillary thyroid carcinoma (PTC).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched to retrieve related literature. A meta-analysis was performed using STATA11.0, Meta-Disc 1.4 and RevMan 5.3.

RESULTS

This meta-analysis included six studies involving 987 lymph nodes from 194 patients. The pooled sensitivity, specificity, and area under the summary receiver-operating characteristic curve (AUC) of OSNA for detecting LNM were 0.88, 0.90, and 0.95, respectively.

CONCLUSION

OSNA assay is an accurate molecular diagnosis for intraoperative detection of lymph node metastasis in PTC.

Cytomorphologic features as predictors of aggressiveness in patients with pT1 papillary thyroid carcinoma: a retrospective study of associations with clinicopathological parameters in 226 fine-needle aspirates

Background

Distinguishing aggressive pT1 papillary thyroid carcinomas (PTCs) from indolent PTCs before or during surgery is important. To the best of our knowledge, few reports in the literature have examined the value of the cytomorphologic features of PTC as predictors of aggressiveness.

Methods

This retrospective study included 226 pT1 PTC patients who underwent preoperative fine-needle aspiration cytology (FNAC) and surgery at Peking University Cancer Hospital between January 2018 and December 2019. Data on the clinical characteristics and pathological results were obtained from the electronic medical record database. All FNAC smears were blindly reviewed by two independent cytopathologists, and the associations between nine cytomorphologic features (lymphocytes, multinucleated giant cells, cellularity, cellular adhesiveness, nuclear size, nuclear pleomorphism, nuclear membrane regularity, intranuclear pseudoinclusions and the amount of cytoplasm) and clinicopathological parameters were statistically analyzed.

Results

Univariate analysis showed that cellularity, intranuclear pseudoinclusions, cellular adhesiveness, nuclear size, and nuclear pleomorphism were strong predictors of some clinicopathological parameters such as extracapsular invasion (ECI) and lymph node metastasis (LNM). Multivariate analysis confirmed that cellular adhesiveness was a strong independent predictor of ECI (P=0.001) and LNM (P<0.001), and the amount of cytoplasm can also predict LNM (P=0.024).

Conclusions

Cytomorphologic features including cellular adhesiveness and the amount of cytoplasm in preoperative FNAC smears could be a valuable tool for predicting ECI or LNM and may be predictors of aggressiveness in patients with pT1 PTC.

Pretracheal-laryngeal lymph nodes in frozen section predicting contralateral paratracheal lymph nodes metastasis

BACKGROUND

There has been an ongoing debate concerning the predictors of contralateral paratracheal lymph nodes metastasis (LNM) in unilateral papillary thyroid cancer (PTC). This study aimed to explore the value of pretracheal-laryngeal lymph nodes (LNs) in frozen section in predicting contralateral paratracheal LNM.

METHODS

A total of 242 patients with unilateral PTC were enrolled in this prospective study. Patients who underwent total thyroidectomy and bilateral central lymph nodes dissection (LND) were divided into two groups according to positive or negative contralateral paratracheal LNs. Patients' demographics and clinicopathological features were compared between the two groups. Validity indexes and consistency of pretracheal-laryngeal LNs in frozen sections were calculated.

RESULTS

LNM rates in central, ipsilateral paratracheal, pretracheal-laryngeal, and contralateral paratracheal regions were 55.37%, 47.03%, 23.55% and 14.05%, respectively. Only pretracheal-laryngeal LNM, regardless of whether detected in frozen or paraffin sections, were independent risk factors for contralateral paratracheal LNM (OR = 2.707; 95% CI 1.062-6.902; P = 0.037 in frozen section; OR = 3.072; 95% CI 1.248-7.560; P = 0.015 in paraffin section). The sensitivity, specificity, false-negative rate, false-positive rate, accuracy rate, and Kappa value of pretracheal-laryngeal LNM in frozen sections for predicting pretracheal-laryngeal LNM were 87.72%, 100%, 12.28%, 0%, 97.11% and 0.916 respectively, while those for predicting contralateral paratracheal LNM were 85,29%, 89.90%, 14.71%, 10.10%, 89.22%, and 0.618 respectively.

CONCLUSION

Pretracheal-laryngeal LNs in frozen section accurately predicted contralateral paratracheal LNM, which could allow the identification of patients who can benefit from an extended central LND.

Clinical feasibility of imaging with indocyanine green combined with carbon nanoparticles for sentinel lymph node identification in papillary thyroid microcarcinoma

BACKGROUND

Although several previous studies demonstrated the feasibility and efficacy of indocyanine green (ICG) for thyroid cancer surgery, ICG was administered through venous injection and focused on parathyroid gland protection. We thus aimed to study the feasibility of imaging using ICG combined with carbon nanoparticles (CNs) in the identification of sentinel lymph nodes (SLNs) in patients diagnosed with papillary thyroid microcarcinoma (PTMC).

METHODS

Two approaches were applied to detect lymph nodes in PTMC surgery. Patients were randomized into 2 groups. ICG and CNs were injected into the thyroid in Group A. In Group B, only CNs was injected. Black-stained or fluorescent nodes observed using near-infrared fluorescence imaging systems were defined as SLNs. SLN and central lymph node (CLN) dissection was completed in both groups. The pathological and postoperative outcomes were compared between 2 groups.

RESULTS

There were 40 patients in Group A and 60 in Group B. A total of 138 SLNs were identified; 72 and 66 SLNs were detected and dissected in Groups A and B, respectively. The number of SLNs identified (per patient) in Group A was higher than that in Group B (P = .027). The number of harvested CLNs was 161 and 192 in Groups A and B, respectively, out of which 45 and 48 lymph nodes with metastasis were confirmed by permanent pathology. The CLN metastatic rate in Group A was higher than that in Group B (P = .048).

CONCLUSION

Imaging using ICG combined CNs is feasible and safe for SLN identification in PTMC patients. Compared with using only CNs, more SLNs can be removed and more metastatic lymph nodes can be confirmed when using the combined method. Although the combined method appears to accurately stage tumors, further research is needed.

The potential role of carbon nanoparticles-assisted biopsy for sentinel lymph nodes of incidental thyroid carcinoma

Background

Some thyroid cancers are found after thyroidectomy for benign lesions, implying additional surgery and treatments. This work aimed to investigate the role of intraoperative sentinel lymph node biopsy (SLNB) for diagnosis of incidental thyroid carcinoma.

Methods

This was a retrospective study of 541 consecutive patients who underwent thyroid surgery between 02/2012 and 02/2014 at the Hunan Provincial People's Hospital. All patients were diagnosed with thyroid benign lesions preoperatively and intraoperatively. Among them, 375 underwent successful intraoperative SLNB using carbon nanoparticles (CNs).

Results

The preoperative diagnoses were nodular goiter (n=472), Hashimoto's disease with nodules (n=24), hyperthyroidism with nodules (n=16), and thyroid cysts with obstructive symptoms (n=29). In the SLNB group, SLN metastasis of thyroid microcarcinoma was confirmed in 21/392 cases (5.4%). These 21 patients received radical surgical treatment for thyroid carcinoma during the initial operation. In the no-SLNB group (n=149), seven patients (4.7%) were finally diagnosed with thyroid microcarcinoma. Six patients had to undergo a second surgery.

Conclusions

Intraoperative SLNB could help diagnose differentiated thyroid microcarcinoma that may be missed preoperatively and intraoperatively. This could prevent the need for a second surgery since the intraoperative frozen section examination of the SLNs can reveal metastasis from thyroid cancer.

Intraoperative frozen section for detection of occult metastasis in clinically N0 neck does not improve outcome in oral cavity carcinomas

OBJECTIVE

The objective of this study was to evaluate the utility of frozen section (FS) in detecting occult nodal metastasis in cN0 OSCC and its impact on regional failure and survival.

MATERIALS AND METHODS

Clinical records of patients of OSCC operated from January 2013 to December 2014 were retrospectively reviewed. These patients were divided into two groups-Group A comprised of patients who underwent selective neck dissection (SND) (level III/IV) and FS based completion (level IV ± V); Group B included patients who underwent SND I-III/IV without FS. The sensitivity and specificity of FS in detecting occult metastasis was calculated. The regional failure rates and overall survival (OS) between the two groups were compared.

RESULTS

The sensitivity, specificity, PPV (positive predictive value) and NPV (negative predictive value) of FS in detecting occult metastasis were 64.06%, 100%, 100%, and 92.15%, respectively. There was no significant difference in regional failure rates (p = 0.219) and OS (p = 0.08) between the two groups.

CONCLUSION

FS has a poor sensitivity in detecting occult nodal metastasis. FS-guided neck dissection does not have a significant impact in reducing regional failure or improving OS in clinically node-negative neck in oral cavity carcinomas.

Sentinel Lymph Node Biopsy in Small Papillary Thyroid Cancer: A Meta-analysis

PURPOSE

The aim of this study was to compare reported results on available techniques for sentinel lymph node detection rate (SDR) in papillary thyroid cancer (PTC).

METHODS

The MEDLINE database was searched via a PubMed interface to identify original articles regarding sentinel lymph node biopsy (SNB) in thyroid cancer. Studies were stratified according to the sentinel lymph node (SLN) detection technique: vital-dye (VD), Tc-nanocolloid planar lymphoscintigraphy with the use of intraoperative hand-held gamma probes (LS), both Tc-nanocolloid planar lymphoscintigraphy with intraoperative use of hand-held gamma probe and VD (LS + VD), Tc-nanocolloid planar lymphoscintigraphy with the additional contribution of preoperative SPECT/CT, and intraoperative use of hand-held gamma probe (LS-SPECT/CT). Pooled SDR values were presented with a 95% confidence interval (CI) for each SLN detection techniques. A Z-test was used to compare pooled SDR estimates. False-negative rates were summarized for each method.

RESULTS

Forty-five studies were included. Overall SDRs for the VD, LS, LS + VD, and LS-SPECT/CT techniques were 83% (95% CI, 77%-88%; I = 78%), 96% (95% CI, 90%-98%; I = 68%), 87% (95% CI, 65%-96%; I = 75%), and 93% (95% CI, 86%-97%; I = 0%), respectively. False-negative rates were 0% to 38%, 0% to 40%, 0% to 17%, and 7% to 8%, respectively.

CONCLUSIONS

In patients with PTC, Tc-nanocolloids offer a higher SDR than that of the VD technique. The addition of SPECT/CT improved identification of metastatic SLNs outside the central neck compartment.

Sentinel lymph node biopsy in small papillary thyroid cancer. A review on novel surgical techniques

PURPOSE

Sentinel lymph node biopsy (SNB) in patients with papillary thyroid carcinoma (PTC) and negative for clinically neck lymph node metastatic involvement (N0) has emerged as a promising minimally invasive procedure to detect metastatic nodes.

METHODS

The MEDLINE database was searched via the PubMed interface on 10 January 2018 for the MeSH headings "sentinel lymph node biopsy" and "thyroid carcinoma".

RESULTS

Vital blue dye, radioisotope, and the combination of both techniques are used in PTC patients. These methods and the emerging role of SPECT/CT are discussed in this review. The sentinel lymph node (SLN) identification rates ranged from 0 to 100% for blue dye, 83 to 100% for radioisotopes, and 66 to 100% for the combination of both techniques, respectively.

CONCLUSIONS

SNB based on radioisotope technique with the use of intraoperative gamma-probe is an accurate and safe method that allows the highest SLN detection rate. There is sufficient evidence to propagate the increasing use of SNB procedure that has the potential to avoid prophylactic lymph node surgery in patients clinically N0.

One-step nucleic acid amplification analysis of sentinel lymph nodes in papillary thyroid cancer patients

INTRODUCTION

It is essential to look for methods to define the need for central lymphadenectomy for papillary thyroid cancer patients. The aim is to determine the efficacy of one-step nucleic acid amplification (OSNA) and sentinel lymph node (SLN) biopsy in the intraoperative detection of nodal involvement.

MATERIAL AND METHODS

This prospective, experimental study enrolled 49 patients with clinically negative lymph nodes. Intraoperatively, 1% Patent Blue dye was injected intratumorally. Lymph nodes that stained blue were defined as SLNs. They were directly cut into blocks at 2-mm intervals. Nonadjacent blocks were subjected to either the OSNA assay or histological examination.

RESULTS

Sixty-five SLNs were found in 43 (87.8%) patients. There were 20 (30.8%) histopathologically positive SLNs. According to the OSNA, 22 (33.8%) SLNs were positive. The OSNA results were different from histopathology in 8 (12.3%) SLNs. The OSNA gave a positive result in 5 (7.7%) SLNs, while they were not involved according to the histopathology. However, OSNA upstaged N status from N0 to N1 only in 2 (3.1%) patients. Inverse results (histopathology +, OSNA-) were obtained in 3 (4.6%) SLNs. Positive and negative predictive values (PPV and NPV) for OSNA were 0.77 and 0.93, respectively. The concordance rate between examinations was 85.5%.

CONCLUSIONS

In some patients with clinically negative lymph nodes, OSNA and SLN biopsy may prevent unnecessary central lymphadenectomy. On the other hand, the sentinel lymph node biopsy may reveal the presence of potentially involved sentinel lymph nodes outside the central compartment. These SLNs can also be assessed by means of OSNA.

Indications and extent of central neck dissection for papillary thyroid cancer: An American Head and Neck Society Consensus Statement

BACKGROUND

The primary purposes of this interdisciplinary consensus statement were to review the relevant indications for central neck dissection (CND) in patients with papillary thyroid cancer (PTC) and to outline the appropriate extent and relevant techniques required to accomplish a safe and effective CND.

METHODS

A writing group convened by the American Head and Neck Society (AHNS) Endocrine Committee was tasked with identifying the important clinical elements to consider when managing the central neck compartment in patients with PTC based on available evidence in the literature, and the group's collective experience. The position statement paper was then submitted to the full Endocrine Committee, Education Committee, and AHNS Council.

RESULTS

This consensus statement was developed to inform the clinical decision-making process when managing the central neck compartment in patients with PTC from the AHNS. This document is intended to provide clarity through definitions as well as a basic guideline from which to manage the central neck. It is our hope that this improves the quality and reduces variation in management of the central neck, facilitates communication, and furthers research for patients with thyroid cancer.

CONCLUSION

This represents, in our opinion, contemporary optimal surgical care for this patient population and is endorsed by the American Head and Neck Society. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1269-1279, 2017.

Utility of sentinel lymph node biopsy for thyroid cancer: a comprehensive review

Sentinel lymph node biopsy (SLNB) is a minimally invasive lymphatic mapping technique, used to identify lymph node micrometastases and stage multiple cancer types. Despite the performance of SLNB for thyroid cancer having been under study since 1998, its role has remained controversial. The objective of this review is to summarize current research reporting on SLNB for thyroid cancer, focusing on recent studies of its application to differentiated thyroid cancer. The technique and potential benefits of SLNB are reviewed with regards to its ability to identify lymph node metastases, aid in cancer prognostication, and direct surgical and medical treatment.