Sentinel node biopsy in early oral squamous cell carcinomas: Long-term follow-up and nodal failure analysis

Prognostic study of sentinel lymph node biopsy in early-stage oral squamous cell carcinoma with computed tomography lymphography

PURPOSE

Occult metastasis is a prognostic factor for early-stage oral squamous cell carcinoma (OSCC). Sentinel lymph node (SLN) biopsy (SLNB) is a promising method to detect such metastases. The present study aimed to evaluate the diagnostic reliability of SLNB with computed tomography lymphography (CTL) for early-stage OSCC and to clarify patient outcomes after SLNB.

METHODS

The medical records of 42 patients with T1 or T2 cN0 OSCC who had undergone CTL the day before surgery were retrospectively collected and statistically analyzed.

RESULTS

SLNs were identified on CTL in 41 of 42 OSCC patients (97.6 %). Micrometastases were detected in 10 of 41 cases (24.4 %) and 11 of 65 SLNs (16.9 %) by intraoperative pathological diagnosis. Three cases showed occult metastasis within a year after the primary operation. Specificity and negative predictive value were 76.9 % and 90.3 %, respectively. The cumulative 5-year regional recurrence-free rate was 89.7 % in 31 SLNB-negative patients. Five-year overall and disease-free survival rates were 86.9 % and 70.1 %, respectively, in the 41 cases with identified SLNs.

CONCLUSION

CTL offers acceptable results and appears likely to be effective in treating early-stage OSCC patients with low-invasive surgery. Further investigation is necessary to compare radioisotope-based methods.

Sentinel lymph node biopsy in early-stage oral squamous cell carcinoma: A retrospective single-center analysis

Sentinel lymph node biopsy (SLNB) is increasingly incorporated in European national guidelines for the management of the clinically node-negative neck (cN0) in early-stage oral squamous cell carcinoma (OSCC). In Germany, SLNB in OSCCs is not yet routinely performed. This study aimed to evaluate the clinical outcome of SLNB in a German cohort. Patients with primary early-stage OSCC who underwent tumor resection and SLNB were retrospectively analyzed. Clinical-pathological characteristics were documented. Primary endpoints were sensitivity and the negative predictive value (NPV). A total of 46 patients with a mean age of 62.3 (±14.5) years met the inclusion criteria. Most tumors were located in the tongue (63.0%). Bilateral drainage from a lateral tumor was observed in three cases (6.5%), and sentinel lymph node metastasis was detected in three patients (6.5%). Mean follow-up for all patients was 13.8 months (±9.6). One patient developed regional recurrence following a negative SLNB during the observation period, leading to an NPV of 0.98 and a sensitivity of 75.0%. The 2-year neck-specific relapse-free survival was 92.8%. SLNB in early-stage OSCC is a reliable diagnostic tool of the cN0 neck, ensuring a high NPV and RFS. SLNB can be advantageous in comparison to elective neck dissection due to the detection of contralateral lymph drainage.

Ultra-fast confocal fluorescence microscopy for neck lymph node imaging in head and neck cancer

OBJECTIVES

We evaluated ultra-fast confocal fluorescence microscopy (UFCM) as a new modality for pathology practice in head and neck cancer (HNC). This was assessed through an ex vivo study to estimate the accuracy, specificity, and sensitivity of interpretation of UFCM images by pathologists for the detection of metastatic lymph nodes in HNC patients undergoing sentinel lymph node biopsy or selective or complete neck dissection.

MATERIALS AND METHODS

44 patients with 32 cN0 and 12 cN+ HNC were included. The macroscopically non-invaded fresh bisected lymph nodes were stained with acridine orange and imaged with Histolog® Scanner (UFCM). Two pathologists interpreted independently the UFCM images postoperatively and gave a consensus diagnosis in case of disagreement. The gold standard was the diagnosis based on hematoxylin-eosin-saffron (HES) sections.

RESULTS

201 lymph nodes were imaged by UFCM. Thirty nodes (15 %) were invaded on final histology: 3 with micrometastases and 27 with macrometastases. The concordance rate between the pathologists on the UFCM images was 192/201 = 95.5 % and the Cohen kappa coefficient was 0.80. The accuracy of UFCM was 95.5 % (95 %CI: 91.7 %-97.9 %) with a high specificity at 98.8 % (95 %CI: 95.8 %-99.9 %) but an insufficient sensitivity at 76.7 % (95 %CI: 57.7 %-90.1 %). The three micrometastases and four of the 27 macrometastases were missed on UFCM images.

CONCLUSION

The UFCM is providing promising detection values with a very good specificity and moderate sensitivity carrying room for improvement.

Use of Indocyanine Green Near-Infrared Imaging for Sentinel Lymph Node Biopsy in Early Oral Squamous Cell Carcinoma: A Pilot Study

PURPOSE

The current established technique for sentinel lymph node (SLN) biopsy is preoperative injection of 99mtechnetium-labeled nanosized colloids (99mTc) followed by single photon emission computed tomography and standard computed tomography (SPECT/CT) with subsequent intraoperative gamma probe-guided excision of the SLN. It is however time and resource consuming, causes radiation exposure and morbidity for the patient as the injection is done in the awake patient. Recently near-infrared imaging with indocyanine green (ICG) gained importance in SLN biopsy as a faster and more convenient technique. The objective of our study was to investigate the feasibility of SLN biopsy using ICG-imaging in early oral squamous cell carcinoma (OSCC).

METHODS

Single-centre pilot study of five patients with early-stage OSCC. For all patients, both techniques (99mTc and ICG) were performed. We injected 99mTc preoperatively in the awake patient, followed by SPECT/CT imaging. Intraoperatively ICG was injected around the primary tumor. Then the neck incision was performed according to the SPECT/CT images and SLN were detected by using a gamma probe and near-infrared fluorescence imaging of the ICG-marked lymph nodes intraoperatively. The excised lymph nodes were sent to histopathological examination according to the SLN dissection protocol.

RESULTS

In all five patients sentinel lymph nodes were identified. A total of 7 SLN were identified after injection of 99mTc, imaging with SPECT/CT and intraoperative use of a gamma probe. All these SLN were fluorescent and visible with the ICG technique. In two patients, we could identify additional lymph nodes using the ICG technique. Pathological analysis demonstrated occult metastasis in two of the cases.

CONCLUSIONS

Our study shows that ICG-guided SLN biopsy is a feasible technique, especially in combination with conventional radioisotope method and may help for intraoperative localization of SLN. Validation studies with bigger patient cohorts are needed to prove our results.

Management of clinically node-negative early-stage oral cancer: network meta-analysis of randomized clinical trials

The best treatments for the clinically node-negative (cN0) neck in early-stage oral squamous cell carcinoma (OSCC) patients are a subject of ongoing debate and there is no consensus. A network meta-analysis (NMA) of randomized clinical trials (RCTs) was conducted to determine the most effective treatment and to rank treatments based on their effectiveness. A systematic search was performed in accordance with the PRISMA guidelines to retrieve RCTs that compared therapeutic neck dissection (TND), sentinel lymph node biopsy (SLNB), and elective neck dissection (END). The outcomes analysed were overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), and nodal recurrence. Hazard ratios and risk ratios were calculated by direct meta-analysis and NMA. Ten RCTs with a total of 1858 patients were eligible for inclusion. Direct meta-analysis showed END to be superior to TND and comparable to SLNB. The NMA revealed no statistically significant difference between END and SLNB (very low quality evidence) regarding OS, DSS, DFS, and nodal recurrence. However, END was found to significantly improve OS and DFS, and reduce nodal recurrence when compared to TND (moderate quality evidence). END ranked as probably the top treatment option for maximizing OS and DSS, and reducing nodal recurrence in early-stage OSCC, followed by SLNB and TND. There was very low quality evidence supporting SLNB as non-inferior to END for patients with early-stage OSCC. This NMA yielded favourable results for the use of END (with moderate quality evidence) in early-stage OSCC patients, although excellent results have also been obtained with SLNB. However, data in the literature for SLNB are scarce, as this technique has not yet been formalized in many countries. There is a need to further explore SLNB for early-stage OSCC patients, as well as its value in detecting occult lymph node metastases on the contralateral side. More studies comparing morbidity, quality of life, and costs between the different management strategies for the clinically negative neck in early-stage OSCC patients are needed.

Sentinel lymph node biopsy versus elective neck dissection in management of the clinically negative (cN0) neck in patients with oral squamous cell carcinoma: A systematic review and meta-analysis

Oral squamous cell carcinoma (OSCC) is the most prevalent type of head and neck cancer, and lymph node metastasis is a crucial prognostic factor that has a direct correlation with the survival rate. The standard procedure for managing clinically negative (cN0) neck in OSCC patients is elective neck dissection (END), but it can lead to various complications that affect the patient's quality of life. Therefore, medical professionals are exploring the use of the sentinel lymph node biopsy (SLNB) to manage cN0 neck in OSCC patients. The aim of this systematic review and meta-analysis was to compare the overall survival (OS) and disease-free survival (DFS) of patients undergoing SLNB and END in the surgical management of early cN0 neck in OSCC patients. To conduct this study, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used to report the systematic reviews. The study included all comparative clinical studies, including randomized clinical trials (RCTs), clinical perspective studies, and retrospective studies that compared END to SLNB for early cN0 neck in OSCC patients. The hazard ratio (HR) and risk ratio (RR) with 95% confidence interval (CI) were calculated using comprehensive meta-analysis. The primary outcome variables were OS, DFS, and disease-specific survival (DSS). The secondary outcome variable was the nodal recurrence rate without local or distant metastasis. The GRADE system was used to assess the evidence's certainty. The meta-analysis included 12 clinical studies, comprising three RCTs and seven non-RCTs. The results showed no statistically significant difference between END and SLNB concerning OS (HR = 0.993, CI: 0.814 to 1.211, P = 0.947, low-quality evidence), DFS (HR = 0.705, CI: 0.408 to 1.29, P = 0.21, low-quality evidence), and nodal recurrence (RR = 1.028, CI: 0.969 to 1.090, P = 0.907, low-quality evidence). Additionally, SLNB was non-inferior to END regarding DSS (RR = 1.028, CI: 0.969 to 1.090, P = 0.907, low-quality evidence). In conclusion, this research affirms the safety and precision of SLNB as a means to stage cN0 OSCC patients, with outcomes that are comparable to END in terms of survival and nodal recurrence. Nevertheless, it's crucial to acknowledge that the quality of evidence in this study was relatively low. Therefore, additional RCTs comparing END to SLNB are warranted to validate these results and offer more robust guidance for managing cN0 OSCC patients.

Health-related quality of life, functional outcomes, and complications after sentinel lymph node biopsy and elective neck dissection in early oral cancer: A systematic review

BACKGROUND

Elective neck dissection improves survival in early oral cancer. Sentinel lymph node biopsy may also do this with less morbidity. This systematic review compared health-related quality of life, functional outcomes, and complications after sentinel lymph node biopsy and elective neck dissection in early oral cancer.

METHODS

PRISMA guidelines were followed. Thirteen studies met inclusion criteria.

RESULTS

Results favoring sentinel lymph node biopsy were found in complications, scar length and appearance, length of hospital stay, time to drain removal, and objective shoulder measures at timepoints up to 12 months. Where differences in health-related quality of life were found, methodological issues make their clinical significance questionable.

CONCLUSIONS

Sentinel lymph node biopsy was associated with fewer complications and statistically better outcomes in a number of physical measures. There is as yet no strong evidence to suggest it is associated with better health-related quality of life outcomes. While a number of health-related quality of life outcome measures show promise, their interpretation is hampered by methodological concerns. Further rigorous research is required to address this.

Nodal frozen section + elective neck dissection as an alternative to sentinel lymph node biopsy for the management of cT1-2N0 oral squamous cell carcinoma patients: a viability and accuracy study

PURPOSE

Oral Squamous Cell Carcinoma (OSCC) is characterized by a high aggressiveness and a tendency to metastasize. The management of the neck in cT1-2N0 patients c follows three strategies: watchful waiting, elective neck dissection (END) or sentinel lymph node biopsy (SLNB). The aim was to assess the viability of intraoperative frozen sections of the nodes of cT1-2N0 to spot occult metastases as an alternative to SLNB, performing a modified radical neck dissection (MRND) in intraoperatively positive patients.

METHODS

The patients were treated at the Maxillo-Facial Surgery Unit of Policlinico San Marco of Catania between 2020 and 2022. END was performed in all patients, including frozen section examination of at least one clinically suspicious node per level. In case of positivity after frozen section examination, neck dissection was extended to levels IV and V.

RESULTS

All frozen sections were compared with a definitive test after paraffin inclusion. During surgery, 70 END were performed, and 210 nodes were analyzed with frozen sections. Among the 70 END, 52 were negative after frozen Sects. (156 negative nodes), and surgery was ended. Five of the 52 negative ENDs resulted in pN + after paraffin inclusion (9.6%), which underwent postoperative adjuvant treatment. The sensibility of our END + frozen section method was 75%, while the specificity of our test was 94%. The negative predictive value was 90,4%.

CONCLUSIONS

Elective neck dissection + intraoperative frozen section could be an alternative to SLNB to spot occult nodal metastases in cT1-2N0 OSCC due to the opportunity to perform a one-step diagnostic/therapeutic procedure.

Current Treatment Strategies and Risk Stratification for Oral Carcinoma

Management of oral cavity squamous cell carcinoma (OSCC) involves a multidisciplinary team approach. Surgery is ideally the primary treatment option for nonmetastatic OSCC, and less invasive curative surgical approaches are preferred in early-stage disease to minimize surgical-related morbidity. For patients at high risk of recurrence, adjuvant treatment using radiation therapy or chemoradiation is often used. Systemic therapy may also be used in the neoadjuvant setting (for advanced-stage disease with the intent of mandibular preservation) or in the palliative setting (for nonsalvageable locoregional recurrence and/or distant metastases). Patient involvement in treatment decision is the key for patient-driven management, particularly in clinical situation with poor prognosis, for example, early postoperative recurrence before planned adjuvant therapy.

Role of Sentinel Lymph Node Drainage Mapping for Localization of Contralateral Lymph Node Metastasis in Locally Advanced Oral Squamous Cell Carcinoma - A Prospective Pilot Study

Aim/Background

Sentinel lymph node biopsy (SLNB) has become the standard of care for nodal staging in early-stage oral squamous cell carcinoma (OSCC) as an alternative to elective neck dissection. However, the role of sentinel lymph node (SLN) and lymphatic drainage mapping with image-guided surgery has not been studied in locally advanced OSCC. Therefore, this study was undertaken to evaluate the role of lymphatic drainage mapping in the identification of contralateral cervical lymph node metastasis in locally advanced OSCC (Stage III-IVb).

Materials and Methods

We have prospectively analyzed treatment-naïve patients of locally advanced, lateralized OSCC (n = 20). All patients underwent SLN imaging using peritumoral injection 0.5-1.0 mCi of 99 mTc-Sulfur colloid (Filtered) and intraoperative identification of contralateral neck nodes using a handheld gamma probe (Crystal Photonics).

Results

A total of 20 patients (18 males and 2 females) with a median age of 52.5 (33-70 years) were included. Ipsilateral SLN was localized in 18 (90%) patients. Bilateral cervical nodes were visualized only in 7 (35%) patients on lymphoscintigraphy (LSG). Out of the seven patients, 5 patients underwent bilateral neck dissection and 2 patients had unilateral neck dissection with LSG-guided exploration of contralateral cervical node and intraoperative frozen section examination. Six out of these seven patients had one or other risk factor for contralateral metastasis (patients had either primary in the tongue, involvement of floor of mouth, or tumor thickness >3.75 mm). On postoperative HPE, only 1/20 (5%) patient showed metastasis in the contralateral cervical lymph node.

Conclusion

Correct identification of metastatic disease in contralateral neck directly influences clinical management, as it can reduce contralateral neck failure rate and limit the morbidity associated with unnecessary contralateral neck dissection, and it is also crucial in radiotherapy planning in locally advanced OSCC. In the current study, lymphatic drainage mapping showed a metastatic rate of 5% in the contralateral neck nodes in locally advanced, lateralized OSCC. However, the role of SLNB and lymphatic drainage mapping in this subgroup of OSCC needs to be studied in larger population to validate these findings.

Occult nodal metastases in T1-T2cN0 oral squamous cell carcinoma: Correlation between sentinel node positivity and completion neck dissection analysis

OBJECTIVES

Sentinel node procedure (SN) is a standard procedure that has shown its safety and effectiveness for T1/T2 cN0 oral squamous cell carcinoma (OSCC), with completion neck dissection (CND) for patients with positive SN. The aim of this study was to characterize the nodal involvement in a cohort of SN + OSCC.

MATERIALS AND METHODS

Patients with T1/T2 cN0 OSCC with positive SN with CND were included in this single-center, prospective cohort study between 2000 and 2013.

RESULTS

54/301 patients had at least one positive SN. In 43/54 (80 %) cases, only the SN(s) were invaded; with only one SN involved (SN+=1) in 36/54 (67 %) cases. No predictive factors of nodal involvement in the CND were found considering the followings: SN micro/macrometastases, primary tumor's depth of invasion (DOI), perineural spread, lymphovascular involvement, primary tumor location, T stage and extranodal extension. The SN micrometastatic involvement (n = 22) was significantly associated with only one SN + CND- (p = 0.017). In the group of patients with unique micrometastatic involvement in the SN (n = 20/54), there was a higher isolated nodal recurrence free time (p = 0.017).

CONCLUSION

80% of T1/T2 cN0 OSCC with positive SN had no other lymph node metastases in the CND, questioning the potential benefits of this procedure. Predictive factors such as the size of the SN metastasis need to be tested to stratify the risk of positive non-SN lymph nodes leading to a personalized treatment, lowering the therapeutic morbidity while maintaining the oncologic safety.

Role of sentinel lymph node biopsy for oral squamous cell carcinoma: Current evidence and future challenges

Sentinel lymph node biopsy (SLNB) has been used across oncological specialties for prognostication, staging, and identification of occult nodal metastasis. Recent studies demonstrated the potential clinical utility of SLNB in oral cavity squamous cell carcinoma (OCSCC). Elective neck dissection is the current standard of care in early management of OCSCC with depth of invasion greater than 2-4 mm; however, majority of patients ultimately do not have nodal disease on final pathology. SLNB is an alternative procedure widely adopted in early cancer management in many oncological subspecialities. Several considerations such as depth of invasion, nodal mapping, histopathology methods, operator variability, postoperative complications, and advancement in preoperative and intraoperative imaging technology can guide the appropriate application to SLNB in OCSCC. The aim of this review is to discuss the current evidence for SLNB in the treatment of early stage OCSCC, imaging technologies that support SLNB procedures, and studies that are currently underway.

Neck and Shoulder Morbidity in Patients with Oral Cancer and Clinically Negative Node Neck Status: A Comparison between the Elective Neck Dissection and Sentinel Lymph Node Biopsy Strategies

The choice for the most optimal strategy for patients with a cT_1-2N₀ carcinoma of the oral cavity, sentinel lymph node biopsy (SLNB) or elective neck dissection (END), is still open for debate in many head and neck cancer (HNC) treatment centers. One of the possible benefits of the less invasive SLNB could be reduced neck and shoulder morbidity. Recent studies have shown a benefit in favor of SLNB the first year after intervention, but the long-term consequences and differences in neck morbidity remain unclear. This cross-sectional study aimed to research differences in neck and shoulder morbidity and Health-Related Quality of Life (HR-QoL) in patients with a cT_1-2N₀ carcinoma of the oral cavity, treated with either END or SLNB. Neck and shoulder morbidity and HR-QOL were measured with patient-reported questionnaires (SDQ, SPADI, NDI, NDII, EORTC-QLQ-C30, EORTC-QLQ-HN35) and active range of motion (AROM) measurements. In total 18 patients with END and 20 patients with SLNB were included. We found no differences between END and SLNB for long-term neck morbidity, shoulder morbidity, and HR-QOL. The significant differences found in the rotation of the neck are small and not clinically relevant.

Efficacy of different sentinel lymph node biopsy protocols in oral squamous cell carcinoma: Systematic review and meta-analysis

The sentinel node biopsy (SNB) is highly protocolized in other cancers, however, this is not the case for oral squamous cell carcinoma patients, hence our objective was to evaluate the different protocols published. A specific study protocol was designed and subsequently registered on PROSPERO (Ref. CRD42021279217). Twenty‐three articles were included in the meta‐analysis. The grouped sensitivity of the SNB was 82% (95% CI: 0.74–0.88), and the grouped specificity was 100% (95% CI: 0.99–1.00). The use of other radiotracers other than pre‐operative lopamidol showed higher values of sensitivity of 82.80% (95% CI: 76.90%–87.50%; p < 0.001). The use of the blue dye stain showed higher sensitivity values of 85.60% (95% CI: 71.90%–93.20%), compared to sensitivity values of 77.50% when it was not used (95% CI: 69.10%–84.20%) (p < 0.001). Diagnostic rates are variable and they were significantly better when 99mTc was used in all its variations and accompanied by the blue dye staining.

Critical Review of the Current Evidence on Sentinel Node Biopsy in Oral Cancer

PURPOSE OF REVIEW

With contemporary surgery of the cN0 neck in early oral cancer becoming more selective, sentinel node biopsy (SNB) is gaining popularity as a possible alternate option to elective neck dissection (END). This review attempts to critically appraise the current evidence and highlight pertinent arguments for the use of SNB in early oral cancers.

RECENT FINDINGS

Based on the recent randomized trials, it is imperative to perform an END at the time of primary resection in cN0 oral cancers. The much criticized false negative rate of SNB can be argued to be equal to the regional failure rate after END for pN0 necks, possibly making a case for SNB due to the reduction in number of neck dissections. There still lies ambiguity on the technique, protocols, and benefit of SNB over END. The role of extended histopathological techniques and the implications of micrometastasis and isolated tumor cells for treatment intensification remain questionable. Currently, SNB is an intermediary between routine imaging and END that needs to evolve before it can become a practice changing alternative to END itself. More efforts are needed in standardizing the protocols for SNB.

Does SLNB substitute END in the future with the sole advantage of preventing shoulder morbidity?

SLNB has emerged as a rational proposition in the management of early-stage oral cancer and has mixed responses within the oncological community. It is high time for the clinicians to look into the fact that, when a patient post-surgery has a regional recurrence within 6 months, it could be reasonable to believe that a tumor seed which was earlier an isolated tumor cell (ITC) or in the form of a micro-metastasis (MM) would have led to this. SLNB has the potential to become a standard of care in the future owing to the development and utility of better evaluation tools to pick nodal metastasis. It is not an overemphasizing statement to say that SLNB could become a standard recommendation in the near future, however, it still looks like a distant dream considering its logistical and technological limitations.

Sentinel Lymph Node Biopsy Versus Elective Node Dissection in Stage cT1-2N0 Oral Cavity Cancer

OBJECTIVE

To compare overall survival (OS) and disease-free survival (DFS) between sentinel lymph node biopsy (SNB) and elective neck dissection (END) in the surgical management of cT1-2N0 oral cavity squamous cell carcinoma (OCSCC).

METHODS

English full-text articles were searched in PubMed and Embase on May 9, 2021. Articles had to compare SNB with END in cT1-T2N0 OCSCC patients; report hazard ratios (HRs), Kaplan-Meier curves, or P-values with total number of events for survival outcomes; be from a clinical trial, cohort, or case-control study. Two reviewers reviewed articles and a third settled disagreements. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the Risk of Bias in Non-randomized Studies of Interventions tool and revised Cochrane risk-of-bias tool for randomized trials were used. The generic inverse variance method with a random-effect model was used for meta-analysis.

RESULTS

Ten studies, five retrospective, three prospective, and two randomized controlled trials, were included (total number of patients [n] = 10,498, END n = 9102, SNB n = 1396). No significant differences were found in OS (HR = 0.92; 95% confidence interval [CI]: 0.65-1.31) or DFS (HR = 0.70; 95% CI: 0.41-1.20). Heterogeneity was not detected in pooled OS analysis (P = .18; I²  = 30%), but was in pooled DFS analysis (P = .003; I²  = 66%).

CONCLUSIONS

No statistically significant differences in OS or DFS were observed between SNB and END in cT1-2N0 OCSCC, suggesting that SNB might be an alternative to END in the management of early-stage, clinically node-negative OCSCC. Laryngoscope, 2021.

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.

Lip and Oral Cavity Squamous Cell Carcinoma

Lip and oral cavity squamous cell carcinoma (SCC) develop from progressive dysplasia of these mucosal structures. The cancers are often preceded by premalignant lesions, and any nonhealing ulcers of the lip or oral cavity should be biopsied. Some risk factors for these 2 subsites overlap and include tobacco use, alcohol use, and an immunocompromised state. Lip and oral cavity SCC are clinically staged based on physical examination and imaging. The 5-year overall survival for early-stage lip and oral cavity SCC is around 70% to 90% but decreases to about 50% for late-stage disease.

Sentinel lymph node biopsy versus elective neck dissection in squamous cell carcinoma of the oral cavity with a clinically N0 neck: Systematic review and meta-analysis of prospective studies

Sentinel lymph node biopsy (SLNB) is an emerging strategy for managing early-stage oral squamous cell carcinoma (SCC) with a clinically N0 (cN0) neck. However, the role of SLNB in this scenario is debatable. Herein, relevant literature was systematically reviewed, and a meta-analysis was performed to evaluate the potential dividends of SLNB compared to elective neck dissection (END) for these patients. The meta-analysis, including six prospective studies, showed comparable results of the two management strategies in terms of regional recurrence (risk ratio [RR] = 0.99; 95% confidence interval [CI], 0.58-1.70), 5-year disease-free survival (RR = 0.99; 95% CI, 0.87-1.11), and 5-year overall survival (RR = 1.01; 95% CI, 0.90-1.13). Fewer adverse events occurred in the SLNB arm than in the END arm (RR = 0.12; 95% CI, 0.02-0.70). Overall, SLNB results in as favorable an oncologic prognosis for patients with cN0 oral SCC as END, while significantly lessening side effects and unnecessary surgeries.

Serial step sections at narrow intervals with immunohistochemistry are required for accurate histological assessment of sentinel lymph node biopsy in oral squamous cell carcinoma

BACKGROUND

Sentinel lymph node (SLN) biopsy is an accurate staging modality in early oral squamous cell carcinoma (OSCC), but its accuracy relies on labor-intensive histopathology protocols. We sought to determine whether serial step sections with immunohistochemistry (SSSIHC) at narrow intervals of the entire SLN are required to accurately exclude metastasis.

METHODS

Consecutive SLN biopsies over a 13-year period were retrospectively evaluated. If the index section was negative for carcinoma, the entire SLN was subjected to SSSIHC at 150 μm intervals. The first section level and total number of section levels to contain carcinoma were recorded.

RESULTS

One hundred and eighteen SLN+ from 90 patients were included. SSSIHC upstaged the nodal status in 19.5% of patients. Metastasis was identified in 16.7% and 10.2% beyond section levels 4 and 6, respectively. Among SLNs requiring SSSIHC, 47.5% contained carcinoma in a single section level.

CONCLUSION

SSSIHC of the entire SLN at 150 μm intervals are required to identify occult metastasis in OSCC.

Sentinel lymph node biopsy versus selective neck dissection in patients with early oral squamous cell carcinoma: A cost analysis

OBJECTIVE

Sentinel lymph node biopsy (SLNB) has been proved to be as efficient as selective neck dissection (SND) for the treatment of occult metastases in T1-T2cN0 oral squamous cell carcinoma (OSCC). The aim of our study was to assess and compare the cost of these two surgical procedures.

PATIENTS AND METHODS

This retrospective cost analysis includes consecutive patients treated between 2012 and 2017 in two French hospitals either by SLNB or SND. Hospital cost (hospital stay for initial surgery and re-hospitalizations over a period of 60 days after the initial surgery), the length of hospital stay for the initial surgery and the perioperative management were described and compared between the two techniques. The propensity score regression adjustment method was used to address selection bias.

RESULTS

Ninety-four patients underwent SLNB procedure and seventy-seven patients underwent SND. The length of hospital stay for initial surgery was lower in SLNB group: 5.8 days (SD: 3.8) versus 9.2 days (SD: 5) in the SND group. Hospital costs were lower in SLNB group: €7 489 (standard deviation: €3 691) versus €8 886 (standard deviation: €4 381) but this difference was not significant after propensity score regression adjustment. The rate of complication, the delay of full oral feeding and postoperative drainage were lower in SLNB group.

CONCLUSION

SLNB in T1-T2cN0 OSCC is less invasive than SND with fewer complications, a shorter length of hospital stay and favorable perioperative management. This study shows that this technique could be also less expensive than SND.

High-risk early-stage oral tongue squamous cell carcinoma, when free margins are not enough: Critical review

Oral tongue squamous cell carcinoma (OTSCC) is a quite peculiar disease from an anatomical and biological standpoint. An increasing amount of literature highlights the existence of a small subset of T1-T2N0 OTSCC, properly resected on a margin-dependent basis, which conversely proved higher than expected rates of loco-regional/distant failure and disease-specific mortality. These specific high-risk tumors might not have a margin-dependent disease and could possibly benefit from a more aggressive upfront loco-regional treatment, especially addressing the so-called T-N tract. Widespread adoption of a histopathological risk model would allow early recognition of these high-risk diseases and, consequently, intensification of the traditional treatment strategies in that specific niche. We reviewed the available knowledge trying to shed light on the potential determinants of the dismal prognosis of these high-risk OTSCC, with special reference to the role of overlooked T-N tract involvement and possible alternatives in terms of elective neck management and risk stratification.

Contralateral Regional Recurrence in Lateralized or Paramedian Early-Stage Oral Cancer Undergoing Sentinel Lymph Node Biopsy-Comparison to a Historic Elective Neck Dissection Cohort

Introduction: Nowadays, two strategies are available for the management of the clinically negative neck in early-stage (cT1-2N0) oral squamous cell carcinoma (OSCC): elective neck dissection (END) and sentinel lymph node biopsy (SLNB). SLNB stages both the ipsilateral and the contralateral neck in early-stage OSCC patients, whereas the contralateral neck is generally not addressed by END in early-stage OSCC not involving the midline. This study compares both incidence and hazard of contralateral regional recurrences (CRR) in those patients who underwent END or SLNB.

Materials and Methods: A retrospective multicenter cohort study, including 816 lateralized or paramedian early-stage OSCC patients, staged by either unilateral or bilateral END (n = 365) or SLNB (n = 451).

Results: The overall rate of occult contralateral nodal metastasis was 3.7% (30/816); the incidence of CRR was 2.5% (20/816). Patients who underwent END developed CRR during follow-up more often than those who underwent SLNB (3.8 vs. 1.3%; p = 0.018). Moreover, END patients had a higher hazard for developing CRR than SLNB patients (HR = 2.585; p = 0.030). In addition, tumor depth of invasion was predictive for developing CRR (HR = 1.922; p = 0.009). Five-year disease-specific survival in patients with CRR was poor (42%) compared to patients in whom occult contralateral nodal metastases were detected by SLNB or bilateral END (88%), although not statistically different (p = 0.066).

Conclusion: Our data suggest that SLNB allows for better control of the contralateral clinically negative neck in patients with lateralized or paramedian early-stage OSCC, compared to END as performed in a clinical setting. The prognosis of those in whom occult contralateral nodal metastases are detected at an earlier stage may be favorable compared to those who eventually develop CRR, which highlights the importance of adequate staging of the contralateral clinically negative neck.

Unilateral versus bilateral nodal irradiation: Current evidence in the treatment of squamous cell carcinoma of the head and neck

Cancers of the head and neck region often present with nodal involvement. There is a long-standing convention within the community of head and neck radiation oncology to irradiate both sides of the neck electively in almost all cases to include both macroscopic and microscopic disease extension (so called elective nodal volume). International guidelines for the selection and delineation of the elective lymph nodes were published in the early 2000s and were updated recently. However, diagnostic imaging techniques have improved the accuracy and reliability of nodal staging and as a result, small metastases that used to remain undetected and were thus in the past included in the elective nodal volume, will now be included in high-dose volumes. Furthermore, the elective nodal areas are situated close to the parotid glands, the submandibular glands and the swallowing muscles. Therefore, irradiation of a smaller, more selected volume of the elective nodes could reduce treatment-related toxicity. Several researchers consider the current bilateral elective neck irradiation strategies an overtreatment and show growing interest in a unilateral nodal irradiation in selected patients. The aim of this article is to give an overview of the current evidence about the indications and benefits of unilateral nodal irradiation and the use of SPECT/CT-guided nodal irradiation in squamous cell carcinomas of the head and neck.

Sentinel lymph node biopsy versus elective neck dissection: long-term oncologic outcomes in clinically node-negative tongue cancer

Objectives

The aim of this study was to compare the long-term oncologic outcomes of sentinel lymph node biopsy (SLNB) versus elective neck dissection (END) in clinically node-negative (cN0) tongue cancer.

Methods

This was a retrospective cohort study of patients with cN0 tongue cancer from a single institution, including 91 patients in the SLNB group and 120 patients in the END group.

Results

The overall recurrence rate showed no significant difference between the two groups. The regional control rate was also comparable between the two groups (P=0.490). The 5-year recurrence-free survival (RFS) was slightly better in the SLNB group than in the END group (P=0.427). The 5-year overall survival (OS) rate was 89.9% in the SLNB group versus 91.9% in the END group (P=0.737). In a propensity-matched subgroup analysis, the type of neck management did not affect RFS or OS.

Conclusion

SLNB showed non-inferior oncologic outcomes compared to END in patients with cN0 tongue squamous cell carcinoma.

Diagnostic yield of sentinel lymph node biopsy in oral squamous cell carcinoma T1/T2-N0: systematic review and meta-analysis

The objective of this study was to conduct a systematic review and meta-analysis on the efficacy of sentinel lymph node biopsy (SLNB) in T1/T2-N0 oral squamous cell carcinoma (OSCC). A systematic review of the literature on SLNB until March 2019 was conducted. The review was organized according to the PRISMA protocol, considering the following PICO (population, intervention, comparison, outcome) question: What is the sensitivity of sentinel lymph node biopsy in OSCC? 'P' was patients with head and neck squamous cell carcinoma T1/2-N0; 'I' was SLNB; 'C' was neck treated with elective neck dissection and haematoxylin-eosin histopathology; 'O' was sensitivity and specificity. A meta-analysis and meta-regression were performed on the selected studies. The sensitivity of SLNB was up to 88% (95% confidence interval (CI) 72-96%) and specificity was up to 99% (95% CI 96-100%). The area under the summary receiver operating characteristic curve was 0.99 (95% CI 0.98-1.00). In the four studies where immunohistochemistry was performed, both the sensitivity and specificity were higher than in the studies without immunohistochemistry: 93% (95% CI 88-97%) and 98% (95% CI 96-100%), respectively. In conclusion, SLNB is an effective technique for treating patients with some types of stage T1/2-N0 OSCC. Some parameters such as immunohistochemistry could determine the level of diagnostic accuracy.

Novel Diagnostic Approaches for Assessment of the Clinically Negative Neck in Head and Neck Cancer Patients

In head and neck cancer, the presence of nodal disease is a strong determinant of prognosis and treatment. Despite the use of modern multimodality diagnostic imaging, the prevalence of occult nodal metastases is relatively high. This is why in clinically node negative head and neck cancer the lymphatics are treated “electively” to eradicate subclinical tumor deposits. As a consequence, many true node negative patients undergo surgery or irradiation of the neck and suffer from the associated and unnecessary early and long-term morbidity. Safely tailoring head and neck cancer treatment to individual patients requires a more accurate pre-treatment assessment of nodal status. In this review, we discuss the potential of several innovative diagnostic approaches to guide customized management of the clinically negative neck in head and neck cancer patients.

What is the role of sentinel lymph node biopsy in the management of oral cancer in 2020?

Approximately 70–80% of patients with cT1-2N0 oral squamous cell carcinoma (OSCC) ultimately prove to have no cancer in the cervical lymphatics on final pathology after selective neck dissection. As a result, sentinel lymph node biopsy (SLNB) has been adopted during the last decade as a diagnostic staging method to intelligently identify patients who would benefit from formal selective lymphadenectomy or neck irradiation. While not yet universally accepted, SLNB is now incorporated in many national guidelines. SLNB offers a less invasive alternative to elective neck dissection (END), and has some advantages and disadvantages. SLNB can assess the individual drainage pattern and, with step serial sectioning and immunohistochemistry (IHC), can enable the accurate detection of micrometastases and isolated tumor cells (ITCs). Staging of the neck is improved relative to END with routine histopathological examination. The improvements in staging are particularly notable for the contralateral neck and the pretreated neck. However, for floor of mouth (FOM) tumors, occult metastases are frequently missed by SLNB due to the proximity of activity from the primary site to the lymphatics (the shine through phenomenon). For FOM cancers, it is advised to perform either elective neck dissection or superselective neck dissection of the preglandular triangle of level I. New tracers and techniques under development may improve the diagnostic accuracy of SLNB for early-stage OSCC, particularly for FOM tumors. Treatment of the neck (either neck dissection or radiotherapy), although limited to levels I–IV, remains mandatory for any positive category of metastasis (macrometastasis, micrometastasis, or ITCs). Recently, the updated EANM practical guidelines for SLN localization in OSCC and the surgical consensus guidelines on SLNB in patients with OSCC were published. In this review, the current evidence and results of SLNB in early OSCC are presented.

Challenges and outcomes in establishing a sentinel lymph node biopsy service for oral squamous cell carcinoma in a regional district specialist hospital

UK national guidelines in 2016 recommended that sentinel lymph node biopsy (SLNB) should be offered to patients with early oral squamous cell carcinoma (OSCC). We review the establishment of an OSCC SLNB service with specific consideration to resources, service implications and patient outcomes. A review of processes was performed to identify key stages in establishing the service, and subsequently a retrospective cohort study consisting of 46 consecutive patients with T1/T2 N0 OSCC was undertaken. The key stages identified were: coordinating a nuclear medicine pathway and reliable cost-appropriate pathology service, constructing a Trust business case, and gaining approval of a new interventional service policy. A median (range) of 3.3 (1-8) sentinel nodes (SLN) were removed, with 17 patients having a positive SLN. The negative predictive value of SLNB was 100%, with 12 having a SLN outside the field if elective neck dissection (END) was planned. There was a significantly increased risk of a positive SLN with increasing depth of invasion (DOI) (p=0.007) and increased diameter (p=0.036). We also identified a longer-than-ideal time to completion neck dissection and inadequate ultrasound follow up of negative SLNB patients. Establishment of a service requires careful planning. Our results were in keeping with those reported in the literature, and showed that SLNB for OSCC has a high negative predictive value and can identify at-risk SLN outside the traditional END levels, even in well-lateralised tumours. Our findings show that DOI and size of SLN were significantly associated with a positive SLN, and also identified areas requiring improvement.

Lymphoscintigraphy for Sentinel Node Mapping in Head and Neck Cancer

The aim of this comprehensive review is to describe and analyze the role of the sentinel node mapping in head and neck cancers. For this purpose, head and neck neoplasms have been categorized in cutaneous malignancies and neoplasms of the upper aerodigestive tract. A concise description of lymphatic drainage will be the "prelude" for each section, as well as the description of the injection techniques, when specific. Concisely, the attention has been focused on detection rate of the sentinel node by lymphoscintigraphy for each cancer, and for those patients in which the sentinel lymph node has been identified, true-positives rates, false-negative rates, and overall accuracy has been pointed out. Overall, in cutaneous neoplasms of the head and neck, the detection rate is higher than 90%, however the false-negative rate is still an issue, in particular in melanoma, inducing the need for newer developments. In fact, new tracers and techniques are already available, while prospective multicenter trials exploring the outcome impact are needed in the near future. For the upper aerodigestive tract and in particular oral cavity and oropharynx, sentinel lymph node identification by lymphoscintigraphy allows avoiding unnecessary neck dissection and/or node irradiation. Even in this case, the main limit remains the risk of false-negative rates. While, for patients affected by laryngeal and hypopharyngeal cancers the data seem very limited and, although the feasibility has been demonstrated, performances of this lymphoscintigraphy still need to be confirmed by multicenter studies.

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.

Comparison Between PET-CT-Guided Neck Dissection and Elective Neck Dissection in cT1-2N0 Tongue Squamous Cell Carcinoma

Objective: Neck management in cT1-2N0 tongue squamous cell carcinoma (SCC) remains controversial. Our goal was to compare the survival difference between PET-CT–guided neck dissection and elective neck dissection (END) for the treatment of cT1-2 tongue SCC.

Methods: Patients with surgically treated cT1-2N0 tongue SCC were retrospectively enrolled. These patients were divided into two groups. Group A: The decision of whether to perform neck dissection was mainly based on the results of preoperative PET-CT examinations. Group B: Patients received END treatment without preoperative PET-CT examinations. The study endpoints were regional control (RC) and disease-specific survival (DSS). The Kaplan–Meier method was used to calculate the survival rates.

Results: Group A consisted of 66 patients, and 16 patients underwent neck dissection owing to positive PET-CT results. Group B consisted of 169 patients. The 5-year RC rates in group A and group B were 86 and 87%, respectively, and the difference was not significant (p = 0.731). The 5-year DSS rates in group A and group B were 93 and 90%, respectively, and the difference was not significant (p = 0.583).

Conclusions: Neck dissection can be safely avoided when the PET-CT scan reveals no neck lymph node involvement.

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.

[Sentinel lymph node biopsy in head and neck oncology]

Sentinel lymph node biopsy (SLNB) has been initially developed for melanoma and breast cancers. Its application in head and neck cancers is recent, probably due to the complexity of the lymphatic drainage, the proximity between the primary tumor and the lymph nodes and the critical anatomical structures (such as the facial nerve). In onco-dermatology, SLNB is validated in head and neck surgery for melanoma with Breslow thickness up to 1mm or ulceration, Merkel carcinoma and high-risk squamous cell carcinoma. Considering the malignancies of the upper aerodigestive tract, the feasibility and oncologic safety of SLNB are now established for T1-T2N0 oral and oropharyngeal squamous cell carcinomas. Thus, it could allow patients with negative sentinel nodes to avoid an unnecessary neck dissection, leading to a decrease of morbidity with an quality of life improvement. For some primary locations (e.g., anterior floor of the mouth) with high proximity between tumor and lymph nodes, it is recommended to remove the tumor before the SLNB so as to improve the detection. New techniques of detection are currently being developed with intra-operative procedures and new tracers (such as tilmanocept), leading to a better accuracy of detection and, probably, new indications.

Surgical consensus guidelines on sentinel node biopsy (SNB) in patients with oral cancer

BACKGROUND

The eighth international symposium for sentinel node biopsy (SNB) in head and neck cancer was held in 2018. This consensus conference aimed to deliver current multidisciplinary guidelines. This document focuses on the surgical aspects of SNB for oral cancer.

METHOD

Invited expert faculty selected topics requiring guidelines. Topics were reviewed and evidence evaluated where available. Data were presented at the consensus meeting, with live debate from panels comprising expert, nonexpert, and patient representatives followed by voting to assess the level of support for proposed recommendations. Evidence review, debate, and voting results were all considered in constructing these guidelines.

RESULTS/CONCLUSION

A range of topics were considered, from patient selection to surgical technique and follow-up schedule. Consensus was not achieved in all areas, highlighting potential issues that would benefit from prospective studies. Nevertheless these guidelines represent an up-to-date pragmatic recommendation based on current evidence and expert opinion.

Elective neck dissection in oral squamous cell carcinoma: Past, present and future

In 1994 a decision analysis, based on the literature and utility ratings for outcome by a panel of experienced head and neck physicians, was presented which showed a threshold probability of occult metastases of 20% to recommend elective treatment of the neck. It was stated that recommendations for the management of the cN0 neck are not immutable and should be reconfigured to determine the optimal management based on different sets of underlying assumptions. Although much has changed and is published in the almost 25 years after its publication, up to date this figure is still mentioned in the context of decisions on treatment of the clinically negative (cN0) neck. Therefore, we critically reviewed the developments in diagnostics and therapy and modeling approaches in the context of decisions on treatment of the cN0 neck. However, the results of studies on treatment of the cN0 neck cannot be translated to other settings due to significant differences in relevant variables such as population, culture, diagnostic work-up, follow-up, costs, institutional preferences and other factors. Moreover, patients may have personal preferences and may weigh oncologic outcomes versus morbidity and quality of life differently. Therefore, instead of trying to establish "the" best strategy for the cN0 neck or "the" optimal cut-off point for elective neck treatment, the approach to optimize the management of the cN0 neck would be to develop and implement models and decision support systems that can serve to optimize choices depending on individual, institutional, population and other relevant variables.

Topographical distribution of sentinel nodes and metastases from T1-T2 oral squamous cell carcinomas

OBJECTIVE

The objective is to investigate the topographical distribution of sentinel nodes (SNs) and lymph node metastases in T1-2cN0 oral squamous cell carcinomas (OSCCs).

METHODS

The study entailed a prospective enrolment of 220 patients with clinical T1-2N0 OSCCs who underwent preoperative lymphoscintigraphy (LSG) followed by gamma probe-guided sentinel lymph node biopsy (SLNB). Patients with positive SNs were treated with completion neck dissection. Excised lymph nodes were grouped into the neck level according to the international guidelines.

RESULTS

The SN detection rate by LSG was 99.1%. Patients with midline tumours had bilateral lymphatic drainage on LSG in 15/21 (71.5%). There were 45/199 (22.6%) patients with lateralised tumours that had unexpected bilateral or contralateral drainage patterns on LSG. Fifty-five patients (25.0%) were SLNB positive, and metastases were found in 72/781 (9.2%) of the excised SNs. Metastatic involvement of neck level IV was rare and only observed in patients with anterior tongue cancer. No patients had level V involvement. Eleven patients developed isolated cervical recurrences, with no new primary tumour as origin. The SLNB procedure ensured an overall sensitivity of 83.3% and a negative predictive value of 93.3%.

CONCLUSION

Completion neck dissection of level I-III in SLNB-positive patients might be sufficient in most patients with OSCC except patients with anterior tongue cancer, but further studies are needed to support this potential therapeutic algorithm. Our study showed that SLNB was helpful in clarifying unexpected bilateral or contralateral metastatic drainage patterns. In our cohort, 8/55 patients with occult metastasis would have been missed by elective neck dissection of the ipsilateral neck.