The prevalence of occult metastases in nonsentinel lymph nodes after step-serial sectioning and immunohistochemistry in cN0 oral squamous cell carcinoma

Evaluation of micrometastasis and isolated tumor cells in node-negative early-stage oral tongue squamous cell carcinoma: a cross-sectional study in tertiary-level hospitals in eastern India

OBJECTIVE

The present study aimed to investigate the incidence of micrometastasis (MMs) and isolated tumor cells (ITCs) in node-negative early-stage oral tongue squamous cell carcinoma (T1-T2 N0). The secondary objective was to correlate the incidence with the clinicopathologic parameters of age, sex, depth of invasion, pattern of invasion, host lymphocytic response, and size and grade of primary tumor.

STUDY DESIGN

Micrometastasis and ITCs in cervical nodes of 30 patients with early-stage oral tongue squamous cell carcinoma were detected and compared using 3 methods: routine hematoxylin and eosin staining, serial-sectioning at intervals of 150 microns employing hematoxylin and eosin, and serial sectioning pan-cytokeratin immunostaining. Associations with clinicopathological variables were analyzed.

RESULTS

Metastatic tumor cells were detected in the cervical nodes of 2 patients using serial sectioning and immunohistochemistry, resulting in upstaging of 6.6% of all cases. Level I and II lymph nodes were primarily involved.

CONCLUSIONS

Early-stage oral tongue squamous cell carcinoma has a significant potential for MMs that frequently go undetected in routine histopathologic examination. However, laborious and technique-sensitive, serial sectioning in combination with pan-cytokeratin staining (AE1/AE3) may aid in detecting MMs and ITCs in patients with early-stage OTSCC.

A SPECT/NIR Fluorescence Dual-Modality Imaging Agent Composed of Drugs and Hospital Available Isotope for Preoperative Sentinel Lymph Node Mapping and Intraoperative Biopsy

Background

Sentinel lymph node (SLN) mapping-guided biopsy is crucial for cancer staging and treatment. Optical/nuclide dual-modality imaging agents for mapping SLN are ideal for preoperative planning and intraoperative biopsy, which are enabled by penetration-depth unlimited nuclide imaging and dynamic real-time optical imaging, respectively. However, commonly reported dual-modality imaging agents are composed of novel but safety-unproven materials, making their quick clinical translation challenging. Herein, we report a novel nanoparticle composed of facile hospital-available drugs and isotope for single-photon emission computed tomography (SPECT)/near-infrared (NIR) fluorescence imaging to detect SLNs.

Methods

Indocyanine green-human serum albumin (ICG-HSA) nanoparticles (NPs) were synthesized by ICG-induced HSA self-assembly and further 99mTc-labeling via a one-step, facile hospital-available method. After injecting 99mTc-ICG-HSA into the rats' forepaw pads, the rats' draining axillary lymph nodes were visualized by preoperative mapping with SPECT/CT and intraoperative biopsy with NIR fluorescence. The axillary lymph nodes of rats were identified by pathology and fluorescent staining after execution. Additionally, its toxicity testing and comparison with 99mTc-sulfur colloid imaging were also explored.

Results

The study reported a self-assembled 99mTc-ICG-HSA with a high radiochemical yield (85.6 ± 3.8%). Compared with conventional 99mTc-sulfur colloid, 99mTc-ICG-HSA NPs showed faster SLN identification, higher renal clearance, and lower hepatic retention. Furthermore, NIRF imaging allowed for the accurate visualization of the SLN and guided SLN biopsy intraoperatively. Notably, the 99mTc-ICG-HSA NPs were composed of hospital-available drugs and isotope, which are safe for acute toxicity evaluation by a certified institute.

Conclusion

The proposed 99mTc-ICG-HSA NPs are safe and capable of noninvasive SLN identification and biopsy guidance with multi-modal imaging strategies and could be a promising tool for clinically assisted SLN biopsy.

Diagnostic accuracy of combined optical- and radio-guided SNB for neck staging of oral squamous cell carcinoma lesions in the anterior oral cavity

PURPOSE

The purpose was to investigate the diagnostic performance of bimodal optical and radio-guided sentinel node biopsy (SNB) for oral squamous cell carcinoma (OSCC) sub-sites in the anterior oral cavity.

METHODS

Prospective study of 50 consecutive patients with cN0 OSCC scheduled for SNB was injected with the tracer complex Tc99m:ICG:Nacocoll. A near-infrared camera was applied for optical SN detection. Endpoints were modality for intraoperative SN detection and false omission rate at follow-up.

RESULTS

In all patients, a SN could be detected. In 12/50 (24%) of cases, the SPECT/CT showed no focus in level 1, but intraoperatively a SN in level 1 was optically detected. In 22/50 cases (44%), an additional SN was identified only due to the optical imaging. At follow-up, the false omission rate was 0%.

CONCLUSION

Optical imaging appears to be an effective tool to allow real-time SN identification comprising level 1 unaffected by possible interference of radiation site from the injection.

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.

Detection of melanoma, breast cancer and head and neck squamous cell cancer sentinel lymph nodes by Tc-99m Tilmanocept (Lymphoseek®)

Technetium-99m-labeled Tilmanocept or Lymphoseek® (Cardinal Health, Dublin, Ohio) is a soluble, synthetic molecule with a small diameter (7 nm), which is comprised of technetium-99m chelated to a dextran backbone containing multiple units of mannose ligands with a high affinity for CD206, a receptor located on the surface of macrophages and dendritic cells that are found in high concentration in lymph nodes. It enables quick transit from the injection site and rapid lymph node accumulation. The binding of mannose ligand and CD206 results in the internalization of the ligand and receptor into the cell. Once the Technetium-99m-labeled Tilmanocept (Lymphoseek®) reaches the lymph node, it is readily internalized by the macrophages and dendritic cells within the draining lymph nodes. Technetium-99m-labeled Tilmanocept (Lymphoseek®) has been extensively studied as a radioisotope for detection of sentinel lymph nodes in melanoma, breast cancer and head and neck squamous cell carcinoma in clinical trials. Based on its safety and ability to detect sentinel lymph nodes satisfactorily, it has been approved by the FDA to use as a radioisotope for preoperative lymphoscintigraphy for identification of sentinel lymph nodes in these types of cancer. Further, the FDA has expanded approval of Technetium-99m-labeled for sentinel lymph node mapping of all solid tumors as well as in pediatric patients.

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.

Recent Developments of ICG-Guided Sentinel Lymph Node Mapping in Oral Cancer

Sentinel lymph node (SLN) biopsy has gained attention as a method of minimizing the extent of neck dissection with a similar survival rate as elective neck dissection in oral cancer. Indocyanine green (ICG) imaging is widely used in the field of surgical oncology. Real-time ICG-guided SLN imaging has been widely used in minimally invasive surgeries for various types of cancers. Here, we provide an overview of conventional SLN biopsy and ICG-guided SLN mapping techniques for oral cancer. Although ICG has many strengths, it still has limitations regarding its potential use as an ideal compound for SLN mapping. The development of novel fluorophores and imaging technology is needed for accurate identification of SLNs, which will allow precision surgery that would reduce morbidities and increase patient survival.

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.

The occult nodal metastasis rate of early tongue cancer (T1-T2): A protocol for a systematic review and meta-analysis

OBJECTIVES

In this study, a meta-analysis was conducted to evaluate the occult lymph node metastasis rate in patients with early-stage (T1-T2) oral tongue squamous cell carcinoma. Also, the correlation between occult lymph node metastasis rate and T2 ratio among T1-T2 or the reported year of each study was analyzed to adjust other confound variables.

STUDY DESIGN

Literature search.

METHODS

A systematic computerized search of the electronic databases was carried out for articles published between January 1, 1980, and December 31, 2018, which reported occult nodal metastasis rate in T1 and T2 (separately) tongue cancer patients. Statistical analysis was performed using Comprehensive Meta Analysis version 3.3.070. Publication bias was assessed by the Egger test and Begg funnel plot method. The correlation between occult nodal metastasis rate and T2 ratio or reported year, respectively, was assessed by meta-regression analysis.

RESULTS

From 19 studies, a total of 1567 cases were included in the meta-analysis. By random effects model, the mean occult cervical lymph node metastasis was 24.4% (95% confidence interval; 0.205-0.248). The meta-regression revealed that the T2 ratio and the reported year of the studies did not have a significant effect on the occult metastasis rate (correlation coefficient = 0.531 and 0.002, respectively, and P = .426 and 0.921, respectively).

CONCLUSION

The meta-analysis revealed that the early-stage oral tongue squamous cell carcinoma had a rate of 24.4% for occult nodal metastasis. The occult nodal metastasis rate was not significantly affected by neither T2 ratio among T1-T2 nor reported year of the studies.

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.

uPAR-targeted optical near-infrared (NIR) fluorescence imaging and PET for image-guided surgery in head and neck cancer: proof-of-concept in orthotopic xenograft model

Purpose

Urokinase-like Plasminogen Activator Receptor (uPAR) is overexpressed in a variety of carcinoma types, and therefore represents an attractive imaging target. The aim of this study was to assess the feasibility of two uPAR-targeted probes for PET and fluorescence tumor imaging in a human xenograft tongue cancer model.

Experimental design and results

Tumor growth of tongue cancer was monitored by bioluminescence imaging (BLI) and MRI. Either ICG-Glu-Glu-AE105 (fluorescent agent) or ⁶⁴Cu-DOTA-AE105 (PET agent) was injected systemically, and fluorescence imaging or PET/CT imaging was performed. Tissue was collected for micro-fluorescence imaging and histology. A clear fluorescent signal was detected in the primary tumor with a mean in vivo tumor-to-background ratio of 2.5. Real-time fluorescence-guided tumor resection was possible, and sub-millimeter tumor deposits could be localized. Histological analysis showed co-localization of the fluorescent signal, uPAR expression and tumor deposits. In addition, the feasibility of uPAR-guided robotic cancer surgery was demonstrated. Also, uPAR-PET imaging showed a clear and localized signal in the tongue tumors.

Conclusions

This study demonstrated the feasibility of combining two uPAR-targeted probes in a preclinical head and neck cancer model. The PET modality provided preoperative non-invasive tumor imaging and the optical modality allowed for real-time fluorescence-guided tumor detection and resection. Clinical translation of this platform seems promising.

Feasibility of Real-Time Near-Infrared Fluorescence Tracer Imaging in Sentinel Node Biopsy for Oral Cavity Cancer Patients

Background

Sentinel node biopsy (SNB) is an established method in oral squamous cell carcinoma (OSCC) for staging the cN0 neck and to select patients who will benefit from a neck dissection. Near-infrared fluorescence (NIRF) imaging has the potential to improve the SNB procedure by facilitating intraoperative visual identification of the sentinel lymph node (SN). The purpose of this study was to evaluate the feasibility of fluorescence tracer imaging for SN detection in conjunction with conventional radio-guided technique.

Methods

Prospective study of patients with primary OSCC planned for tumor resection and SNB. Thirty patients were injected peritumorally with a bimodal tracer (ICG-^99mTc-Nanocoll) followed by lymphoscintigraphy and SPECT/CT to define the SNs and their anatomical location preoperatively. SNs were detected intraoperatively with a hand-held gamma-probe and a hand-held NIRF camera.

Results

In 29 of 30 subjects (97%), all preoperatively defined SNs could be identified intraoperatively using a combination of radioactive and fluorescence guidance. A total of 94 SNs (mean 3, range 1–5) that were both radioactive and fluorescent ex vivo were harvested. Eleven of 94 SNs (12%) could only be identified in vivo using NIRF imaging, and the majority of those were located in level 1 close to the primary tumor.

Conclusions

A combined fluorescent and radioactive tracer for SNB is feasible, and the additional use of NIRF imaging may improve the accuracy of SN identification in oral cancer patients. Intraoperative fluorescence guidance seems of particular value when SNs are located in close proximity to the injection site.

Watchful waiting of the neck in early stage oral cancer is unfavourable for patients with occult nodal disease

For cT1/2N0 oral squamous cell carcinoma (OSCC), treatment of the neck is a matter of debate. Two treatment strategies were evaluated in this study: selective neck dissection (SND) and watchful waiting (WW). One hundred and twenty-three SND patients and 70 WW patients with cT1/T2N0M0 OSCC of the tongue, floor of mouth, or buccal mucosa were analysed retrospectively. Extracapsular spread (ECS), 3-year overall survival (OS), and disease-specific survival (DSS) were determined. Twenty-nine percent of SND patients and 13% of WW patients had occult nodal disease. WW-N+ patients showed thicker tumours as compared to WW-N0 patients (5mm vs. 2mm, P=0.02). WW-N+ patients showed significantly more ECS as compared to SND-N+ patients (56% vs. 14%, P=0.016) and had a significantly worse 3-year DSS than SND-N+ patients (56% vs. 82%, P=0.02). For T1 OSCCs, a watchful waiting policy is acceptable if tumour thickness proves to be <4mm. Otherwise, an additional treatment of the neck is advised, since WW-N+ patients show more ECS, with a worse DSS than SND-N+ patients.

Staging of early lymph node metastases with the sentinel lymph node technique and predictive factors in T1/T2 oral cavity cancer: A retrospective single-center study

BACKGROUND

The purpose of this study was to examine the diagnostic accuracy of detecting lymph node metastases and to identify predictive and prognostic clinicopathological factors in patients with oral squamous cell carcinoma (OSCC) undergoing sentinel lymph node biopsy (SLNB).

METHODS

All patients diagnosed with cT1 to T2N0 OSCC who underwent a diagnostic SLNB between 2007 and 2013 were included.

RESULTS

We identified 253 patients, of whom 27% had a positive sentinel lymph node (SLB). The false-negative rate, sensitivity, and negative predictive value (NPV) were 5%, 88%, and 95%, respectively. Patients with micrometastases as well as macrometastases had a separately, significantly shorter disease-specific survival than patients with pN0 disease. In a logistic regression model, the maximum tumor thickness, perineural invasion, and differentiation grade were independent predictive factors for the presence of metastases.

CONCLUSION

These data support the use of the SLNB technique as an accurate and safe staging tool in patients with OSCC with a cN0 neck. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1033-E1040, 2016.

Detection of Cervical Lymph Node Micrometastases in Patients with Squamous Cell Carcinoma of the Oral Cavity, Pharynx and Larynx

Background: The goal of this prospective study was to determine the frequency of micrometastases in patients with squamous cell carcinoma (SCC) of the oral cavity, pharynx and larynx in whom elective neck dissection was indicated (cN0). Patients and Methods: A total of 12 patients (10 males and 2 females) were enrolled in the study. The age ranged 42–73 years (median 62 years). Elective neck dissection was performed in all patients (8 ipsilateral, 4 bilateral) and a total of 256 lymph nodes were removed and sent for microscopic examination. Results: The presence of tumor cells in cervical lymph nodes was found in 5/12 (42%) patients. Micrometastases of SCC were found in two patients and isolated tumor cells (ITC) in two other patients. In the remaining one patient with oropharyngeal SCC, a micrometastasis of papillary thyroid carcinoma (PTC) was detected. Positive lymph nodes were localized in level II in three patients with SCC of larynx, hypopharynx and tongue base, respectively, in level I in one patient with SCC of oral tongue and in level III in one patient with PTC. Conclusion: Our results indicate that SCC of head and neck has a high potential for creating micrometastases which frequency is higher compared to clinically detected macrometastases. Therefore, elective neck dissection or radiotherapy of the neck should be considered in patients with high risk of occult metastases or micrometastases.

A prospective study on sentinel lymph node biopsy in early oral cancers using methylene blue dye alone

Sentinel Lymph Node (SLN) biopsy using a combination of radioisotopes and blue dyes have a good accuracy rate in predicting subclinical neck nodal metastases in head and neck cancers. However, the limited availability of lymphoscintigraphy facilities in India requires exploration of alternative methods of SLN detection. We evaluated the feasibility of using methylene blue dye alone in detecting SLN in cN0 early oral cancers. 32 patients with cN0 early (T1, T2) oral squamous cell cancers underwent SLN biopsy using peri tumoural methylene blue dye injection. Blue dye stained (SLN) nodes were sent for frozen section analyses. Patients who had microscopic metastases in SLN underwent modified radical neck dissections and the rest underwent selective neck dissections. Paraffin sections and IHC studies were done on all nodes. SLN was identified in 29 patients (Identification rate = 90.6 %) of which SLN was positive for metastases on frozen section in 5 patients. The sensitivity, specificity and NPV of SLN with frozen section were 80 %, 95.8 % and 95.8 % respectively. IHC with cytokeratins increased the sensitivity (100 %) and NPV (100 %) at the loss of specificity (87.5 %). Methylene blue dye alone can be successfully used for SLN identification in early oral cancers with a good accuracy and sensitivity. This method will be of use especially in resource limited countries and centres where nuclear medicine facilities are not widely available. However, it has to be validated by larger randomised multi institutional trials for wider applicability. Immunohistochemistry increases the sensitivity and negative predictive value of SLN but its applicability in real time decision making is limited.

SPECT/CT lymphoscintigraphy of sentinel node(s) for superselective prophylactic irradiation of the neck in cN0 head and neck cancer patients: a prospective phase I feasibility study

Background

Clinically node negative HNSCC patients have a risk ranging between 18 and 45% of occult metastases, making prophylactic irradiation mandatory. Selective irradiation of nodal target volume based on international guidelines is practice. Anyway, about half the tumours lying in an anatomical subsite known to potentially drain bilaterally effectively do so, leading to unnecessary large volume irradiation. Moreover, 15% of the tumours show drainage outside of predicted basin, increasing the risk for potential geographical misses. Three-dimensional SPECT/CT lymphoscintigraphy (LS) of sentinel node(s) may help to individualize nodal target volume selection. This prospective phase I study explores its feasibility and the dosimetric impact.

Methods

Ten cN0 HNSCC patients eligible for definitive radiotherapy were imaged with SPECT/CT after ^99mTc nanocolloid injection around the tumour. The neck levels containing up to four hottest nodes were identified and selected for prophylactic irradiation (CTVn-LS) by volumetric modulated arc therapy. A comparative virtual planning was performed with volumes selected according to international guidelines (CTVn-IG).

Results

Migration was observed in all patients (one with gamma probe only). 2.9 sentinel nodes were detected per patient on average. In some patients, accurate localization was difficult when not using thermoplastic mask for SPECT/CT. CTVn-LS was totally encompassed by CTVn-IG in all patients but one (unpredicted drainage in retropharyngeal level). On average, CTVn-LS and related planning target volumes were two times smaller than IG ones. This led to significant dose decrease in identified organs at risk as well as remaining volume at risk.

Conclusions

SPECT/CT LS is a promising tool to individualize prophylactic node CTV in cN0 HNSCC patients eligible for definitive radiotherapy. Oncological safety must be confirmed by ongoing phase II study.

Use of a novel receptor-targeted (CD206) radiotracer, 99mTc-tilmanocept, and SPECT/CT for sentinel lymph node detection in oral cavity squamous cell carcinoma: initial institutional report in an ongoing phase 3 study

IMPORTANCE

Sentinel lymph node biopsy has been proposed as an alternative to up-front elective neck dissection (END) for determination of pathologic nodal status in patients undergoing surgical treatment for oral cavity squamous cell carcinoma (OSCC) with clinically negative neck (cN0). Sentinel lymph node biopsy using current standard tracer agents and imaging adjuncts such as radiolabeled sulfur-colloid and planar lymphoscintigraphy (LS), however, is associated with several drawbacks.

OBJECTIVE

To assess the preliminary utility of technetium Tc 99m (99mTc)-tilmanocept, a novel molecular imaging agent for sentinel lymph node (SLN) mapping, in OSCC.

DESIGN, SETTING, AND PARTICIPANTS

Prospective, nonrandomized, single-arm, part of an ongoing phase 3 clinical trial. Patients had previously untreated, clinically and radiographically node-negative OSCC (T1-4aN0M0) at an academic tertiary referral center.

INTERVENTIONS

Patients received a single dose of 50 µg 99mTc-tilmanocept injected peritumorally followed by dynamic planar LS and fused single-photon emission computed tomography/computed tomography (SPECT/CT) prior to surgery. Surgical intervention consisted of excision of the primary tumor and radioguided SLN dissection followed by planned END. The excised lymph nodes (SLNs and non-SLNs) underwent histopathologic evaluation for presence of metastatic disease.

MAIN OUTCOMES AND MEASURES

False-negative rate and negative predictive value of SLNB using 99mTc-tilmanocept and comparison of planar LS with SPECT/CT in SLN localization.

RESULTS

Twelve of 20 patients (60%) had metastatic neck disease on pathologic examination. All 12 had at least 1 SLN positive for metastases. No patients had a positive END node who did not have at least 1 positive SLN. These data yield a false-negative rate of 0% and negative predictive value of 100% using 99mTc-tilmanocept in this setting. Dynamic planar LS and SPECT/CT revealed a mean (range) number of hot spots per patient of 2.9 (1-7) and 3.7 (1-12), respectively. Compared with planar LS, SPECT/CT identified additional putative SLNs in 11 of 20 cases (55%).

CONCLUSIONS AND RELEVANCE

The high negative predictive value and low false-negative rate in identification of occult metastases shows 99mTc-tilmanocept to be a promising agent in SLN identification in patients with OSCC. Use of SPECT/CT improves preoperative SLN localization including delineation of SLN locations near the primary tumor when compared with planar LS imaging.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00911326.

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.