Diagnostic Accuracy of Up-Front PET/CT and MRI for Detecting Cervical Lymph Node Metastases in T1-T2 Oral Cavity Cancer-A Prospective Cohort Study

The diagnostic accuracy of up-front 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for detecting cervical lymph node metastases in patients with T1-T2 oral squamous cell carcinoma is reported with large discrepancies across the literature. We investigated the sensitivity, specificity, positive and negative predictive value, and accuracy of up-front PET/CT for detecting cervical lymph node metastases in this patient group and compared the performance to magnetic resonance imaging (MRI). In this prospective cohort study, 76 patients with T1-T2 oral squamous cell carcinoma underwent an up-front PET/CT and MRI at the Odense University Hospital from September 2013 to February 2016. Sentinel node biopsy and elective neck dissection were used for histopathological verification of the imaging modalities. Up-front PET/CT was significantly more sensitive than neck MRI (74% vs. 27%, p = 0.0001), but less specific (60% vs. 88%, p = 0.001). The accuracy of PET/CT and neck MRI was comparable (66% vs. 63%, p = 0.85), the PPV was slightly in favor of neck MRI (56% vs. 62%, p = 0.73), the NPV was slightly in favor of PET/CT (77% vs. 63%, p = 0.16). Neither PET/CT nor neck MRI should stand alone for N-staging T1-T2 oral cavity cancer.

Cost-Effectiveness of [99mTc]Tilmanocept Relative to [99mTc]Sulfur Colloid for Sentinel Lymph Node Biopsy in Early Stage Oral Cavity Cancer

BACKGROUND

Several studies have demonstrated varying rates of efficacy, reliability, and sensitivity of sentinel lymph node biopsy (SLNB) in identifying occult nodal disease for early stage oral cavity squamous cell carcinoma (OCSCC) depending on the radionuclide agent utilized. No head-to-head comparison of cost or clinical outcomes of SLNB when utilizing [99mTc]tilmanocept versus [99mTc]sulfur colloid has been performed. The goal of this study was to develop a decision model to compare the cost-effectiveness of [99mTc]tilmanocept versus [99mTc]sulfur colloid in early stage OCSCC.

PATIENTS AND METHODS

A decision model of disease and treatment as a function of SLNB was created. Patients with a negative SLNB entered a Markov model of the natural history of OCSCC parameterized with published data to simulate five states of health and iterated over a 30-year time horizon. Treatment costs and quality-adjusted life-years (QALYs) for each health state were included. The incremental cost-effectiveness ratio (ICER) was then estimated using $100,000 per additional QALY as the threshold for determining cost-effectiveness.

RESULTS

The base case cost-effectiveness analysis suggested [99mTc]tilmanocept was more effective than [99mTc]sulfur colloid by 0.12 QALYs (7.06 versus 6.94 QALYs). [99mTc]Tilmanocept was more costly, with a lifetime cost of $84,961 in comparison with $84,264 for sulfur colloid, however, the overall base case ICER was $5859 per additional QALY, well under the threshold for cost-effectiveness. Multiple one-way sensitivity analyses were performed, and demonstrated the model was robust to alternative parameter values.

CONCLUSION

Our analysis showed that while [99mTc]tilmanocept is more costly upfront, these costs are worth the additional QALYs gained by the use of [99mTc]tilmanocept.

Diagnostic test accuracy of sentinel lymph node biopsy in squamous cell carcinoma of the oropharynx, larynx, and hypopharynx: A systematic review and meta-analysis

The aim of this meta-analysis was to determine the diagnostic test accuracy of sentinel lymph node biopsy (SLNB) in patients with oropharyngeal, laryngeal, and hypopharyngeal squamous cell carcinoma (SCC). For this purpose, MEDLINE, EMBASE, and Web of Science were searched from inception to March 8, 2022. Included were studies evaluating diagnostic test accuracy of SLNB to identify cervical lymph node metastases with elective neck dissection or follow-up as reference. A bivariate generalized linear mixed model approach was used for the meta-analysis. Nineteen studies were eligible, evaluating 377 cases in total. The pooled estimates of sensitivity and negative predictive value were 0.93 (95% CI: 0.86-0.96) and 0.97 (95% CI: 0.94-0.98), respectively. The excellent accuracy of SLNB justifies a place in the diagnostic workup of patients with larynx and pharynx SCC. Randomized trials are required to demonstrate oncologic safety and benefits on treatment related morbidity and quality of life when omitting elective neck treatment based on SLNB.

Analysis of the Efficiency and Prognostic Value of the Sentinel Node Technique in Oral Squamous Cell Carcinoma after Seven Years

Background and objectives: The purpose of this study was to analyse the diagnostic and prognostic efficiency of the sentinel lymph node biopsy technique (SLNB). Materials and Methods: This is a prospective observational study performed by the Hospital Complex in Santiago de Compostela (CHUS) in Spain, between February 2013 and June 2020. The study included 60 patients, who had been diagnosed with OSCC in stage T1/T2N0M0. Results: 10 patients (16.7%) presented with SN+ (sentinel node positive). The majority (80%) only presented subcapsular affection, however one case also presented with extracapsular affection. Using the Kaplan–Meier curves, we determined that the average survival estimation for SN− patients was 74.0 months (CI95% 67.6–80.5) and it was 45.4 months (CI95% 10.9–24.0) for SN+ patients (p = 0.002). SN+ patients presented an OR = 11.000 (CI95% 2.393–50.589, p = 0.002) for cancer-related mortality. In terms of the diagnostic performance of the SN (sentinel node) test, a 55% sensitivity, a 100% specificity, 100% PPV and a 84% NPV were obtained. The analysis using ROC (receiver operating characteristic) curves revealed an AUC = 0.671 (CI95% 0.492–0.850, p = 0.046). Conclusions: SLNB seems to be an adequate technique for the detection of hidden metastases.

Is the retropharyngeal lymph node the first echelon node for carcinoma tonsil? Prospective evaluation and literature review

PURPOSE

Tonsil cancer being predominantly treated by non-surgical means, there is a paucity of data on lymph nodal drainage pathways and histo-pathologically confirmed metastatic rates. This study assesses the retropharyngeal lymph node (RPLN) in N0 squamous cell carcinoma tonsil as a possible first echelon node and a site for occult metastasis.

METHODS

Prospective study involving treatment naïve N0 carcinoma tonsil treated by primary surgery and adjuvant treatment from June 2017 to March 2019. In-vivo lymph nodal drainage patterns were assessed by sentinel node mapping by preoperative SPECT-CT and intra-operative hand-held Gamma probe. All patients had a subsequent Level I-III/IV sampling neck dissection supplemented with RPLN dissection. Histological evaluation of sentinel nodes and RPLN involved step-serial sectioning and pan-cytokeratin immunohistochemistry. A comprehensive literature review was performed with keywords "retropharyngeal lymph node", "oropharynx", "tonsil", "squamous cell carcinoma" to determine the incidence of RPLN positivity in previously published series.

RESULTS

Sentinel node was successfully identified by SPECT-CT in all 17 patients (ipsilateral level 2a-13/17, 2b-1/17, 3-1/17; bilateral 2a-1/17; isolated contralateral retropharyngeal node-1/17). 8/17 had occult neck metastasis. In no patient was an ipsilateral RPLN identified as the sentinel node. Histological sampling did not indicate metastatic tumor in the RPLN in any patient (0/17). A systematic literature review further confirmed that RPLN metastasis in oropharyngeal cancer is noted only in the presence of pN + disease at other neck levels, and isolated RPLN metastasis is extremely rare (1.2%).

CONCLUSION

The ipsilateral RPLN is not identified either as the first echelon node or as a site of occult metastatic disease in N0 tonsil cancer.

CTRI REGISTRATION

CTRI/2019/06/019551.

Management of the clinically N0 neck in early-stage oral squamous cell carcinoma (OSCC). An EACMFS position paper

Metastasis of oral squamous cell carcinoma (OSCC) to the cervical lymph nodes has a significant impact on prognosis. Accurate staging of the neck is important in order to deliver appropriate treatment for locoregional control of the disease and for prognosis. The management of the neck in early, low volume disease (clinically T₁/T₂ oral cavity tumours) has long been debated. The risk of occult nodal involvement in cT₁/T₂ OSCC is estimated around 20-30%. We describe the natural evolutionary history of OSCC and its patterns of spread and metastasis to the local lymphatic basins. We discuss most published literature and studies on management of the clinically negative neck (cN₀). Particular focus is given to prospective randomized trials comparing the outcomes of upfront elective neck dissection against the observational stance, and we summarize the results of the sentinel node biopsy studies. The paper discusses the significance of the primary tumour histological characteristics and specifically the tumour's depth of invasion (DOI) and its impact on predicting nodal metastasis. The DOI has been incorporated in the TNM staging highlighting its significance in aiding the treatment decision making and this is reflected in world-wide oncological guidelines. The critical analysis of all available literature amalgamates the existing evidence in early OSCC and provides recommendations in the management of the clinically N₀ neck.

Usefulness of Sentinel Lymph Node Biopsy for Oral Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

We assessed the diagnostic accuracy of sentinel lymph node biopsy (SLNB) for detecting neck nodal metastasis in early oral squamous cell carcinoma (OSCC) as an alternative to elective neck dissection.

STUDY DESIGN

A systematic search for relevant literature was conducted in the PubMed, SCOPUS, Embase, Web of Science, and Cochrane databases.

METHODS

Two reviewers individually searched the five databases up to November 2019. For studies that met inclusion criteria, data on patient diagnoses were pooled, including true positives, true negatives, false positives, and false negatives. Methodological quality was checked with the Quality Assessment of Diagnostic Accuracy Studies (version 2) tool.

RESULTS

In total, 98 observational or retrospective studies were included. The diagnostic odds ratio of SLNB was 326.165 (95% confidence interval [CI]: 231.477-459.587; I²  = 0%). The area under the summary receiver operating characteristic curve was 0.982. Sensitivity was 0.827 (95% CI: 0.804-0.848), and specificity was 0.981 (95% CI: 0.975-0.986). The correlation between sensitivity and the false positive rate was -0.076, which indicates that heterogeneity did not exist. Subgroup analyses were performed with the subgroups reference test type, publication year, and study type. No significant difference was found within the reference test type subgroup. However, differences within the publication year and study type subgroups were significant, where the retrospective study subgroup was significantly more sensitive and specific than the prospective study subgroup.

CONCLUSION

Results of this meta-analysis imply that the high specificity of SLNB supports its role as a diagnostic tool for patients with clinical tumor stage (CT)1-2 clinically negative (N0) OSCC. More studies should be done to further verify the results of this study.

LEVEL OF EVIDENCE

2a Laryngoscope, 131:E459-E465, 2021.

Controversies in Oral and Maxillofacial Oncology

Imaging studies are essential components of tumor diagnosis, staging, assessing tumor response to neoadjuvant and adjuvant therapies, and postoperative surveillance on completion of definitive treatment. Treatment of early stage clinically node negative oral cavity squamous cell carcinoma is controversial. Approximately 3% of all head and neck tumors arise within the parotid gland and most often within the superficial lobe, lateral to the facial nerve; about 80% are benign and most are pleomorphic adenoma. In patients with dry eyes failing multiple other treatment modalities and facing ongoing pain and loss of vision, microvascular transplant of the submandibular gland is a viable option.

Sensitivity and specificity of sentinel lymph node biopsy in patients with oral squamous cell carcinomas using indocyanine green fluorescence imaging

PURPOSE

The purpose of this clinical study was to evaluate the sensitivity and specificity of cervical sentinel lymph node biopsy after mapping with indocyanine green fluorescence (ICG) for imaging early-stage oral cancer.

PATIENTS AND METHODS

A sentinel lymph node biopsy (SLNB) was performed during a selective neck dissection (SND) in 20 patients with oral squamous cell carcinoma (OSCC, cT1 or cT2, N0 status). The sentinel lymph nodes (SLN) were identified using an infrared video camera after ICG injection. Lymph nodes were examined histologically. The endpoint of this study was to investigate the rate of false-negative results in SLNB.

RESULTS

Sentinel lymph nodes could be detected after 8.1 min (range 1-22 min). In eight out of 20 cases, lymph node metastases were found during histopathological evaluation of the neck dissection specimen. In four cases a metastasis could be found in the detected SLN (sensitivity 50%). In the other four cases metastases were found in different lymph nodes. Specificity was 100%, positive predictive value 100%, and negative predictive value 75%.

CONCLUSION

In this study, reliability of sentinel lymph node biopsy after ICG imaging could not be verified, as there were false-negative results in 50% of the cases. Therefore, SND can still be recommended as for patients with cT1 or cT2 OSCC, and a N0 neck status.

Predictive Significance of Tumor Depth and Budding for Late Lymph Node Metastases in Patients with Clinical N0 Early Oral Tongue Carcinoma

In clinical N0 early oral tongue carcinoma, treatment of occult lymph node metastasis is controversial. The purpose of this study was to assess the histopathological risk factors for predicting late lymph node metastasis in early oral tongue carcinoma. We retrospectively reviewed 48 patients with early oral tongue squamous cell carcinoma. Associations between the histopathological factors (depth of tumor, differentiation, blood vessel invasion, lymphatic invasion, and tumor budding) and late lymph metastasis were analyzed. Although the univariate analysis identified blood vessel invasion, lymphatic invasion, and high-grade tumor budding as predictive factors for neck recurrence (p < 0.001), the Cox proportional hazards model identified high-grade tumor budding as an independent predictive factor (p < 0.01). The combination of a tumor depth ≥ 3 mm and high-grade tumor budding yielded high diagnostic accuracy. Tumor depth and budding grade were identified as histopathological risk factors for late neck recurrence in clinical N0 early oral tongue carcinoma.

Additional non-sentinel lymph node metastases in early oral cancer patients with positive sentinel lymph nodes

To determine risk factors for additional non-sentinel lymph node metastases in neck dissection specimens of patients with early stage oral cancer and a positive sentinel lymph node biopsy (SLNB). A retrospective analysis of 36 previously untreated SLNB positive patients in our institution and investigation of currently available literature of positive SLNB patients in early stage oral cancer was done. Degree of metastatic involvement [classified as isolated tumor cells (ITC), micro- and macrometastasis] of the sentinel lymph node (SLN), the status of other SLNs, and additional non-SLN metastases in neck dissection specimens were analyzed. Of 27 studies, comprising 511 patients with positive SLNs, the pooled prevalence of non-SLN metastasis in patients with positive SLNs was 31 %. Non-SLN metastases were detected (available from 9 studies) in 13, 20, and 40 % of patients with ITC, micro-, and macrometastasis in the SLN, respectively. The probability of non-SLN metastasis seems to be higher in the case of more than one positive SLN (29 vs. 24 %), the absence of negative SLNs (40 vs. 19 %), and a positive SLN ratio of more than 50 % (38 vs. 19 %). Additional non-SLN metastases were found in 31 % of neck dissections following positive SLNB. The presence of multiple positive SLNs, the absence of negative SLNs, and a positive SLN ratio of more than 50 % may be predictive factors for non-SLN metastases. Classification of SLNs into ITC, micro-, and macrometastasis in the future SLNB studies is important to answer the question if treatment of the neck is always needed after positive SLNB.

Sentinel node biopsy for oral cancer: A prospective multicenter Phase II trial

OBJECTIVE

A recent study identified a survival benefit with prophylactic neck dissection (ND) at the time of primary surgery as compared with watchful waiting followed by therapeutic neck dissection for nodal relapse, in patients with cN0 oral squamous cell carcinoma (OSCC). Alternative management of cN0 neck cancer is recommended to minimize the adverse effects of ND, indicating the need for sentinel node biopsy (SNB) and limited neck dissection. We conducted a multicenter Phase II study to examine the feasibility of SNB for clinically N0 OSCC.

METHODS

Previously untreated N0 OSCC patients (n=57) with clinical late-T2 or T3 tumors were enrolled across 10 institutions. SNB navigated with multislice frozen section analysis of sentinel nodes (SNs) and SNB supported sentinel node lymphatic basin dissection (SN basin dissection) were performed in a one-stage procedure. The endpoint was to investigate the rate of false-negative metastases after SN basin dissection and SNB alone.

RESULTS

Most tumors were late-T2 lesions (n=50; 87.7%). SNs were identified in all patients. A total of 196 SNs were detected. Among these SNs, 35 (17.8%) were positive for metastasis (9 in level I, 12 in level II, 12 in level III, 1 in level V and 2 in the contralateral region of the neck). The false-negative rate of SNB supported by SN basin dissection and SNB alone was 4.5% and 9.1%, respectively. The concordance of the SN status in intraoperative frozen sections with the permanent histopathology was 97.4% (191/196). The sensitivity and specificity of intraoperative pathological evaluation were 85.7% (30/35) and 100% (30/30), respectively. The 3-year overall survival (OS) and disease-free survival was 89.5% and 82.5%, respectively. The OS of SN-negative patients was significantly longer than that of SN-positive patients (P=0.047).

CONCLUSION

The current study verified that SN basin dissection was a useful back-up procedure for SNB performed as a one-stage procedure, showing a low false-negative rate. SNB alone is an appropriate staging method for patients with clinical N0 staging, and a reliable procedure to determine the appropriate levels for neck dissection.

The history of sentinel node biopsy in head and neck cancer: From visualization of lymphatic vessels to sentinel nodes

The aim of this report is to describe the history of sentinel node biopsy in head and neck cancer. Sentinel node biopsy is a minimally invasive technique to select patients for treatment of metastatic lymph nodes in the neck. Although this procedure has only recently been accepted for early oral cancer, the first studies on visualization of the cervical lymphatic vessels were reported in the 1960s. In the 1980s mapping of lymphatic drainage from specific head and neck sites was introduced. Sentinel node biopsy was further developed in the 1990s and after validation in this century the procedure is routinely performed in early oral cancer in several head and neck centers. New techniques may improve the accuracy of sentinel node biopsy further, particularly in difficult subsites like the floor of mouth.

An innovative multimodality approach for sentinel node mapping and biopsy in head and neck malignancies

PURPOSE

Recent innovations such as preoperative SPECT/CT, intraoperative imaging using portable devices and a hybrid tracer were evaluated in a multimodality approach for sentinel node (SN) mapping and biopsy in head and neck malignancies.

MATERIAL AND METHODS

The evaluation included 25 consecutive patients with head and neck malignancies (16 melanomas and 9 oral cavity squamous cell carcinomas). Patients were peritumorally injected with the hybrid tracer ICG-(99m)Tc-nanocolloid. SNs were initially identified with lymphoscintigraphy followed by single photon emission computed tomography (SPECT/CT) 2 hours after tracer administration. During surgery a portable gamma camera in combination with a near-infrared fluorescence camera was used in addition to a handheld gamma ray detection probe to locate the SNs.

RESULTS

In all patients the use of conventional lymphoscintigraphy, SPECT/CT and the additional help of the portable gamma camera in one case were able to depict a total of 67 SNs (55 of them visualized on planar images, 11 additional on SPECT/CT and 1 additional with the portable gamma camera). A total of 67 of the preoperatively defined SNs together with 22 additional SNs were removed intraoperatively; 12 out of the 22 additional SNs found during operation were located in the vicinity of the injection site in anatomical areas such as the periauricular or submental regions. The other 10 additional SNs were found by radioguided post-resection control of the excision SN site.

CONCLUSION

In the present series 26% additional SNs were found using the multimodal approach, that incorporates SPECT/CT and intraoperative imaging to the conventional procedure. This approach appears to be useful in malignancies located close to the area of lymphatic drainage such as the periauricular area and the oral cavity.

Diagnostic evaluation of sentinel lymph node biopsy in early head and neck squamous cell carcinoma: a meta-analysis

BACKGROUND

The purpose of this study was to evaluate the efficacy of sentinel lymph node biopsy (SLNB) in early head and neck squamous cell carcinoma (HNSCC).

METHODS

The PubMed database was searched for studies published before October 31, 2012. Pooled values for the sentinel lymph node identification rate, sensitivity, false-negative rate, negative predictive value, and accuracy were calculated.

RESULTS

A total of 16 studies (987 patients) was included. The pooled identification rate, sensitivity, false-negative rate, negative predictive value, and accuracy were 95.2%, 86.3%, 13.7%, 94.2%, and 95.0%, respectively. The subgroup with high methodological quality showed a mean identification rate of 95.4% for SLNB validation trials and 94.2% for SLNB alone trials, and mean sensitivity of 91.0% for SLNB validation trials and 84.2% for SLNB alone trials.

CONCLUSION

The SLNB procedure has shown a high sensitivity rate, but the pooled sensitivity and false-negative rate were worse in SLNB alone trials than in SLNB validation trials.

Long term results of sentinel lymph node biopsy in early oral squamous cell carcinoma

The objective of the study was to evaluate the long term results of the sentinel node (SN) biopsy technique in the management of the clinically negative (N0) neck in patients with early oral squamous cell carcinoma (T1-T2). Patients with positive SN underwent neck dissection. A sentinel lymph node (SLN) biopsy was performed on 31 consecutive patients. Six of the 31 patients were upstaged by the results of the SLN biopsy. The SLN biopsy allowed the identification of node metastasis in 100% of the cases with a sensitivity of 100%, specificity of 100%, and negative predictive value of 100%. There was a mean follow-up of 59 months. The neck control rate was 100% in the SLN negative group and two SLN positive patients developed subsequent neck disease (neck control rate of 88%). One SLN patient presented at the follow-up with a second primary tumor, 18 months later treated successfully by chemoradiotherapy. The overall survival rate was 100% in both groups. The promising reported short-term results have been sustained by long term follow-up. Patients with negative SLN achieved an excellent neck control rate. The neck control rate in SN negative patients was superior to that in SLN positive patients, but not statistically different.

Novel diagnostic modalities for assessment of the clinically node-negative neck in oral squamous-cell carcinoma

Oral squamous-cell carcinomas arise in mucosal linings of the oral cavity and frequently metastasise to regional lymph nodes in the neck. The presence of nodal metastases is a determinant of prognosis and clinical management. The neck is staged by palpation and imaging, but accuracy of these techniques to detect small metastases is low. In general, 30-40% of patients will have occult nodal disease and will develop clinically detectable lymph-node metastases when the neck is left untreated. The choice at present is either elective treatment or careful observation followed by treatment of the neck in patients who develop manifest metastases. These unsatisfying therapeutic options have been the subject of debate for decades. Recent developments in staging of the neck, including expression profiling and sentinel lymph-node biopsy, will allow more personalised management of the neck.

Occult metastases detected by sentinel node biopsy in patients with early oral and oropharyngeal squamous cell carcinomas: impact on survival

BACKGROUND

Analysis of the lymphatic drainage pattern, the reliability of a negative sentinel lymph node biopsy (SLNB), as well as the impact of sentinel lymph node (SLN) metastases on regional control and survival in patients with early stage oral and oropharyngeal squamous cell carcinoma (SCC).

METHODS

A prospective consecutive cohort analysis was conducted which included 111 patients diagnosed between 2003 and 2010. Endpoints of the study were neck control rate, overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS), depending on the size of occult metastases.

RESULTS

Forty-nine of 111 patients (38%) had positive SLNs, 10 had isolated tumor cells (ITCs), 19 had micrometastases, and 13 had macrometastases. OS, DSS, and DFS at 3 years for SLN-negative and SLN-positive patients was 98% and 71%, 95% and 76%, and 98% and 73%, respectively. Furthermore, there was a statistically significant difference between the SLN-negative group and ITCs in DSS as well as between the SLN-negative group and patients with micrometastases in OS and DSS and between the SLN-negative group and patients with macrometastases in all 3 survival estimates.

CONCLUSION

Our study is the first to demonstrate that even small tumor deposits only detectable by the extensive histopathologic workup of the SLNB protocol have a significant impact on tumor control and survival in early Oropharyngeal SCC. Whether these findings will translate into different treatment strategies based on the upstaged neck has to be further investigated.

Sentinel node biopsy for oral and oropharyngeal squamous cell carcinoma in the previously treated neck

In patients with early stage oral or oropharyngeal squamous cell carcinoma (OSCC) sentinel node biopsy (SNB) is a reliable method to detect occult disease in the neck. However, patients with a history of surgery or radiotherapy in the neck may have aberrant lymphatic drainage caused by disruption of lymphatic channels. Therefore, treatment of the same levels at risk as in the primary setting may not be appropriate. The aim of our prospective observational study was to evaluate the clinical application of SNB in previously treated OSCC. Between 2003 and 2010 twenty-two patients were included. Lymph node mapping consisted of preoperative lymphoscintigraphy, SPECT/CT, intraoperative use of gamma-probe and patent blue. Endpoints were the sentinel node (SN) detection rate, unexpected lymphatic drainage patterns, negative predictive value and regional tumor control. 4/22 (18%) Patients were previously treated only on the contralateral site. The SN detection rate was 100% and unexpected drainage was found in 1/4 patients. The other 18 patients had ipsi- or bilateral previous neck treatment and a SN detection rate of 83%. The upstaging rate was 7% and 67% had unexpected lymphatic drainage patterns. The median follow-up was 22 months. Regional tumor control and negative predictive value were 100%. SNB in previously treated OSCC patients is feasible. SN detection is reliable and regional tumor control after staging by SNB is excellent. Moreover, SNB renders an assessment of the individual lymphatic drainage pattern, compensating for a potential variability after previous treatment of the neck.

Long-term experience in sentinel node biopsy for early oral and oropharyngeal squamous cell carcinoma

OBJECTIVE

Long-term results of sentinel node biopsy (SNB) in early (T1/T2) oral and oropharyngeal squamous cell carcinoma (OSCC) in a single-institution experience.

METHODS

Prospective consecutive cohort analysis of 79 patients (67% male, median age 60 years, age range 34-87 years) included between 2000 and 2006. Lymphatic mapping consisted of preoperative lymphoscintigraphy, single photon emission computed tomography (SPECT/CT), and intraoperative use of a handheld gamma probe. Endpoints of the study were neck control rate, overall (OS), disease-specific (DSS), and disease-free survival (DFS).

RESULTS

Twenty-nine of 79 patients (37%) had positive sentinel nodes (SN). Six of 29 (21%) patients showed isolated tumor cells, 14/29 (48%) micrometastases, and 9/29 (31%) macrometastases. OS, DFS, and DSS at 5 years for the entire cohort were 80, 85, and 87%, for SN-negative patients were 88, 96, and 96%, and for SN-positive patients were 74, 73, and 77%, respectively. Only the difference in DSS achieved statistical significance. The neck control rate after 5 years was 96% in SN-negative and 74% in SN-positive patients. This difference was statistically significant.

CONCLUSIONS

SNB is a safe and accurate staging modality to select patients with clinically stage I/II OSCC with occult lymph node disease for elective neck dissection (END). The promising reported short-term results have been sustained by long-term follow-up. Patients with negative SN and no END achieve an excellent neck control rate which compares favorably with reports on primary END. The neck control rate in SN-negative patients is superior to that in SN-positive patients, which is reflected in superior DSS.

Gene Expression Signatures of Lymph Node Metastasis in Oral Cancer: Molecular Characteristics and Clinical Significances

Even though lymph node metastasis accounts for the vast majority of cancer death in patients with oral cancer (OC), the molecular mechanisms of lymph node metastasis remain elusive. Genome-wide microarray analyses and functional studies in vitro and in vivo, along with detailed clinical observations, have identified a number of molecules that may contribute to lymph node metastasis. These include lymphangionenic cytokines, cell adhesion molecules, basement membrane-interacting molecules, matrix enzymes and relevant downstream signaling pathways. However, defined gene signatures from different studies are highly variable, which hinders their translation to clinically relevant applications. To date, none of the identified signatures or molecular biomarkers has been successfully implemented as a diagnostic or prognostic tool applicable to routine clinical practice. In this review, we will first introduce the significance of lymph node metastasis in OC, and clinical/experimental evidences that support the underlying molecular mechanisms. We will then provide a comprehensive review and integrative analysis of the existing gene expression studies that aim to identify the metastasis-related signatures in OC. Finally, the remaining challenges will be discussed and our insights on future directions will be provided.

Stromal impact on tumor growth and lymphangiogenesis in human carcinoma xenografts

Squamous cell carcinomas (SCCs) arising in the oral cavity are associated with poor survival, mainly due to metastatic disease. In contrast, skin SCCs rarely metastasize and are usually curable. To study influence of tongue and skin stroma on cancer growth and induction of lymphangiogenesis, xenograft tumors of human carcinoma cells were established either in tongue or skin of BALB/c nude mice. Two oral and two skin SCC cell lines were used, as well as an endometrial adenocarcinoma cell line. Tongue tumors established from all cell lines were larger than corresponding skin tumors. Peritumoral lymphatic vessel density was up to five times higher in tongue than in corresponding skin tumors, and mRNA level of the lymphangiogenic growth factor vascular endothelial growth factor (VEGF)-C was twice as high in tongue tumors compared with corresponding skin tumors. Contrary to lymphatic vessel density, blood vessel density was higher in skin tumors than in tongue tumors. In a cohort of patient samples, lymphatic vessel density was found to be higher in tongue SCCs compared with skin SCCs, supporting a clinical relevance of our findings. Our results show that the tumor stroma has a profound impact on cancer growth and induction of lymphangiogenesis and angiogenesis. The difference in lymphatic vessel density between tongue and skin tumors may be important in directing metastatic potential of tumors arising in these organs.

Follow-up after intraoperative sentinel node biopsy of N0 neck oral cancer patients

The objective of the study was to evaluate the validity of sentinel node (SN) biopsy in early oral cancer patients focusing on the accuracy of intraoperative diagnoses of SN status, recurrences in follow-up and impact on patient survival. Previously untreated N0 oral cancer patients were candidates for the study. Using a radioisotope method, an intraoperative SN biopsy was performed. Patients with a positive frozen section of SN underwent immediate neck dissection as a single-stage procedure; they were followed in our outpatient clinic. Forty-five cT1-2N0 patients with squamous cell carcinoma were analyzed. There were seven patients with positive SN, five of whom were detected by intraoperative frozen section analysis. The sensitivity, specificity and accuracy of the intraoperative frozen section analysis of SN were 71.4, 100 and 95.6%, respectively. There were 13 recurrences in the course of all patients treated. Those with positive SN showed a tendency toward recurrence. Three patients with negative SN suffered from delayed ipsilateral neck recurrence. These were considered false negatives at a rate of 7.9%. The 5-year overall survival rate of all patients was 91.1%. SN-positive patient survival was significantly poorer than that of SN-negative patients. Positive SN had a negative impact on the survival. SN biopsy was shown to be a valuable method for determining the neck status of early oral cancer patients. The concordance rate of intraoperative multislice frozen section analysis of SN and patient neck status at the time of operation was 95.6%. SN-positive patients exhibited a tendency toward cancer recurrence. There were three cases of false negatives not conforming to the SN concept and their rate was 7.9%. Positive SN had a negative impact on patient survival.

Joint practice guidelines for radionuclide lymphoscintigraphy for sentinel node localization in oral/oropharyngeal squamous cell carcinoma

Involvement of the cervical lymph nodes is the most important prognostic factor for patients with oral/oropharyngeal squamous cell carcinoma (OSCC), and the decision whether to electively treat patients with clinically negative necks remains a controversial topic. Sentinel node biopsy (SNB) provides a minimally invasive method of determining the disease status of the cervical node basin, without the need for a formal neck dissection. This technique potentially improves the accuracy of histological nodal staging and avoids over-treating three-quarters of this patient population, minimizing associated morbidity. The technique has been validated for patients with OSCC, and larger-scale studies are in progress to determine its exact role in the management of this patient population. This article was designed to outline the current best practice guidelines for the provision of SNB in patients with early-stage OSCC, and to provide a framework for the currently evolving recommendations for its use. These guidelines were prepared by a multidisciplinary surgical/nuclear medicine/pathology expert panel under the joint auspices of the European Association of Nuclear Medicine (EANM) Oncology Committee and the Sentinel European Node Trial Committee.

Sentinel node detection in head and neck malignancies: innovations in radioguided surgery

Sentinel node mapping is becoming a routine procedure for staging of various malignancies, because it can determine lymph node status more precisely. Due to anatomical problems, localizing sentinel nodes in the head and neck region on the basis of conventional images can be difficult. New diagnostic tools can provide better visualization of sentinel nodes. In an attempt to keep up with possible scientific progress, this article reviews new and innovative tools for sentinel node localization in this specific area. The overview comprises a short introduction of the sentinel node procedure as well as indications in the head and neck region. Then the results of SPECT/CT for sentinel node detection are described. Finally, a portable gamma camera to enable intraoperative real-time imaging with improved sentinel node detection is described.

Joint Practice Guidelines for Radionuclide Lymphoscintigraphy for Sentinel Node Localization in Oral/Oropharyngeal Squamous Cell Carcinoma

Involvement of the cervical lymph nodes is the most important prognostic factor for patients with oral/oropharyngeal squamous cell carcinoma (OSCC), and the decision of whether to electively treat patients with clinically negative necks remains a controversial topic. Sentinel node biopsy (SNB) provides a minimally invasive method for determining the disease status of the cervical node basin, without the need for a formal neck dissection. This technique potentially improves the accuracy of histologic nodal staging and avoids overtreating three-quarters of this patient population, minimizing associated morbidity. The technique has been validated for patients with OSCC, and larger-scale studies are in progress to determine its exact role in the management of this patient population. This document is designed to outline the current best practice guidelines for the provision of SNB in patients with early-stage OSCC, and to provide a framework for the currently evolving recommendations for its use. Preparation of this guideline was carried out by a multidisciplinary surgical/nuclear medicine/pathology expert panel under the joint auspices of the European Association of Nuclear Medicine (EANM) Oncology Committee and the Sentinel European Node Trial (SENT) Committee.