Sentinel lymph node biopsy in the staging of oral cancer

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.

Radioactive nanosized colloids and indocyanine green identify the same sentinel lymph nodes in oral squamous cell carcinoma

PURPOSE

Near-infrared fluorescence imaging using indocyanine green (ICG) combined with radioactive markers has the potential to improve sentinel lymph-node (SLN) mapping in oral squamous cell carcinoma (OSCC). This study aimed to evaluate the ability of 99mTc and ICG in identifying the sentinel lymph nodes in patients with early stage OSCC.

METHODS

Data were collected prospectively, and a retrospective analysis of 15 patients with early stage OSCC and a cN0 neck was performed. All patients received peritumoral injection of 99mTc the day before surgery and ICG was administered intraoperatively. Intentionally, the application of the two different tracers were done by two different physicians with varying degrees of experience. The number of identified lymph nodes positive for 99mTc and ICG, the overlap or possible discrepancies of both methods, and the time until fluorescence signals of ICG were detected were noted.

RESULTS

In all patients, a 100% agreement in sentinel lymph-node identification was achieved, regardless of both the exact location of the peritumoral injection and the experience of the injecting surgeon. Time until ICG accumulation in the sentinel lymph node was consistently found to be between 1 and 3 min.

CONCLUSION

ICG constitutes a viable and useful addition to 99mTc for intraoperative sentinel lymph-node detection in this study.

Elastography: the next step

In the past few decades, various tools have emerged that claim to enhance detection of oral cancer. The most important prognostic factor in patients with oral cancer is lymph node status: the presence of nodal spread decreases the 5-year survival rate by approximately 50%. Differentiation between reactive and metastatic lymphadenopathy is thus vital, and one differentiating criterion is hardness (elasticity) of the lymph node. The purpose of this review is to highlight a promising new ultrasound technique, known as elastography, which measures the characteristics of tissue compliance. The principles underlying elastography are that tissue compression produces strain (displacement) within the tissue - which is lower in harder tissues than in softer tissues - and that malignant tissues are generally harder than normal surrounding tissue. Therefore, elastography might yield clinical information useful in diagnosing cervical metastasis and improving prognosis in oral cancer. It has long been used for cancers of the breast, pancreas, and thyroid, and its use in cervical lymphadenopathy is now being explored, which could lead to great advancements in the diagnosis and prognosis of oral cancer.

Cervical lymph node metastasis in oral squamous carcinoma preoperative assessment and histopathology after neck dissection

BACKGROUND

The presence or absence of nodal metastasis has a great impact on the prognosis and survival of patients with head and neck cancer. The risk of occult metastasis is related to the method by which the lymph nodes are evaluated. It is possible to reduce the risk of undiagnosed metastasis with accurate imaging techniques and thus probably reduce the number of elective neck treatments.

AIMS AND OBJECTIVES

To assess the accuracy of clinical palpation, CT Scan, Ultrasound and Ultrasound guided FNAC in prediction of lymph node metastasis in oral squamous cell carcinoma so that a suitable surgical neck dissection can be carried out.

METHODS

Ten patients with oral squamous cell carcinoma who underwent 10 neck dissections (4 RND, 6 SOND) were included. All the patients underwent examination of neck pre operatively by palpation, Computed Tomography with contrast, Ultrasound and Ultrasound guided FNAC for no detection. The findings were correlated with the results of histopathologic examination of the neck specimen. The results were obtained after statistical analysis.

RESULTS

Six neck dissection specimens showed metastatic lymph node involvement in postoperative histopathology. Lymph node involvement was identified preoperatively by palpation in 7 necks, CT in 3 necks, US in 9 necks and USFNAC was positive in 4 cases. The palpation showed 83% sensitivity, 50% specificity. CT showed sensitivity of 50%, specificity of 100%, US showed sensitivity of 100%, specificity of 25% and US-FNAC showed sensitivity of 67%, specificity of 100%.

CONCLUSION

The palpation, CT Scan and US are equally accurate but the USFNAC is the most accurate technique in assessing metastasis in lymph nodes in patients with oral squamous cell carcinoma.