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

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.

A novel near-infrared EGFR targeting probe for metastatic lymph node imaging in preclinical mouse models

For the treatment of patients with oral squamous cell carcinoma (OSCC), the imaging of cervical lymph nodes and the evaluation of metastastic progression are of great significance. In recent years, the development of new non-radioactive lymph node tracers has been an area of intense research. Here, we report the synthesis, good biocompatibility, and in vivo evaluation of a new small molecule near-infrared (NIR) fluorescence probe by the conjugation of Lapatinib to S0456 (LP-S). We show that like Lapatinib, LP-S binds to the epidermal growth factor receptor (EGFR) resulting in high quality fluorescence imaging of metastatic lymph nodes in OSCC mouse models. After local injection of LP-S into the tumor, the lymphatic drainage pathway and lymph nodes can be clearly identified by NIR fluorescence imaging. Further, the LP-S probe shows higher contrast and longer retention in metastatic lymph nodes, allowing them to be differentiated from normal lymph nodes, and affording a new choice for fluorescence-guided surgery. Scheme. Chemical synthesis and application of EGFR targeting probe LP-S for imaging of metastatic lymph nodes (mLNs) in OSCC.

Should an elective contralateral neck dissection be performed in midline-reaching squamous cell carcinomas of the oral cavity and oropharynx?

OBJECTIVE

to compare the rate of occult contralateral neck metastases (OCNM) in oral and oropharyngeal squamous cell carcinomas (SCC) reaching or crossing the midline and to identify risk factors for OCNM.

MATERIALS AND METHODS

we conducted a single-center retrospective study of oral and oropharyngeal SCC with contralateral cN0 neck. The cohort was divided into a midline-reaching (MR; approaching the midline from up to 10 mm) group and a midline-crossing (MC; exceeding the midline by up to 10 mm) group. Clinical N-status was assessed by a radiologist specializing in head and neck imaging. All patients underwent contralateral elective neck dissection (END).

RESULTS

A total of 98 patients were included in this study, 59 in the MR group and 39 in the MC group. OCNM were present in 17.3% of patients, 20.3% in the MR group and 12.8% in the MC group (p = 0.336). In multivariable analysis, MR/MC status as well as distance from the midline (in mm) were not identified as risk factors for OCNM. Conversely, oropharyngeal primary and clinical N-status above N1 were significantly associated with a higher risk of OCNM, with odds ratios (OR) of 3.98 (95% CI = 1.08-14.60; p = 0.037) and 3.41 (95% CI = 1.07-10.85; p = 0.038) respectively.

CONCLUSION

in patients with oral and oropharyngeal SCC extending close to or beyond the midline, tumor origin and clinical N-status should carry the most weight when dictating the indications for contralateral END, rather than the midline involvement in itself.

Sentinel node-assisted neck dissection in advanced oral squamous cell carcinoma-A new protocol for staging and treatment

BACKGROUND

Sentinel lymph node biopsy (SLNB) is used to improve the staging of and guide treatment in patients with early-stage T1-T2 N0 oral squamous cell carcinoma (OSCC). The role of sentinel nodes (SNs) and the use of SN-technique in advanced OSCC (T3-T4 and/or N+) remain to be evaluated. This study investigates the nodal drainage and the rate of positive SNs (SNs+) in all stages of OSCC.

MATERIALS AND METHODS

In total, 85 patients with T1-T4 OSCC diagnosed 2019-2021 were included. We used a prolonged interval between peritumoral injection of radionuclide and SPECT-CT to include all SNs.

RESULTS

Patients with advanced OSCC presented a higher proportion of contralateral lymphatic drainage and a higher rate of SN+ compared to patients with early-stage disease. T3-T4 and N+ tumors presented a tendency for a higher rate of contralateral lymphatic drainage compared to T1-T2 and N0 tumors (p = 0.1). The prevalence of positive nodes (SNs+) was higher among patients with advanced disease, T3-T4 versus T1-T2 (p = 0.0398).

CONCLUSION

SN-assisted ND enables identification and removal of all SNs + and has the potential for more accurate staging and could possibly give prognostic advantages regarding regional recurrence for all OSCC patients, especially among those with advanced disease. The precise localization of the SNs + also suggests that a more individualized ND approach might be possible in the future even for patients with advanced OSCC.

Management of the Contralateral Neck in Unilateral Node-Positive Oral Squamous Cell Carcinoma

INTRODUCTION

In lateralized oral squamous cell carcinoma (OSCC) with ipsilateral cervical lymph node metastasis (CLNM), the surgical management of the unsuspicious contralateral neck remains a matter of debate. The aim of this study was to analyze this cohort and to compare the outcomes of patients with and without contralateral elective neck dissection (END).

MATERIAL AND METHODS

A retrospective analysis of patients with lateralized OSCC, ipsilateral CLNM (pN+) and contralateral cN0-stage was performed. Patients were divided into two groups according to the surgical management of the contralateral neck: I: END; and II: no END performed. Adjuvant radiotherapy was applied bilaterally in both groups according to individual risk.

RESULTS

A total of 65 patients (group I: 16 (24.6%); group II: 49 (75.4%)) with a median follow-up of 28 months were included. Initially, there was no case of contralateral CLNM after surgery. During follow-up, 6 (9.2%) patients presented with recurrent CLNM. In 5 of these cases (7.7%), the contralateral neck (group I: 3/16 (18.8%); group II: 2/49 (4.1%)) was affected. Increased ipsilateral lymph node ratio was associated with contralateral CLNM (p = 0.07). END of the contralateral side showed no significant benefit regarding OS (p = 0.59) and RFS (p = 0.19).

CONCLUSIONS

Overall, the risk for occult contralateral CLNM in patients with lateralized OSCC ipsilateral CLNM is low. Our data suggest that END should not be performed routinely in this cohort. Risk-adapted radiotherapy of the contralateral neck alone seems to be sufficient from the oncological point of view.

Patients of stage I oral cancer with pathologically low‐risk feature managed by primary tumor resection alone: Impact of depth of invasion and a nomogram analysis

Objectives

To evaluate the importance of depth of invasion (DOI) in patients with pathologically low‐risk feature stage I oral squamous cell carcinoma (OSCC) managed by primary tumor resection alone.

Methods

Patients with stage I OSCC, at pathologically low risk, underwent primary tumor resection without neck dissection were enrolled retrospectively between 2007 and 2015. Low risk was defined as the absence of positive or close margins, lymphovascular invasion, perineural invasion, worst pattern of invasion‐5, and poor differentiation in histologic grade. The primary endpoints included overall survival (OS), cancer specific survival (CSS), local recurrence free survival (LRFS), and regional recurrence free survival (RRFS). A nomogram based on the DOI was established for predicting RRFS.

Results

A total of 198 patients were enrolled in this study. DOI was the only prognosticator to achieve statistical significance in all primary endpoints according to univariate analysis. Patients with DOI <3 mm tumor showed better five‐year OS, CSS, LRFS, and RRFS than those with DOI ≥3 mm tumor. The concordance index of the nomogram model without DOI was 0.684, which could increase to 0.733 when DOI was included in the calculation.

Conclusion

Patients with pathologically low‐risk stage I OSCC correlate with a higher chance in occult neck metastasis if increasing DOI (≥3 mm) is noticed. Indeed, the chance of occult neck metastasis is significantly higher in this group (14% vs. 2%) than in those with DOI <3 mm. Elective neck dissection is advised if DOI is ≥3 mm to achieve better clinical outcomes.

Level of Evidence

4.

Identification of occult metastatic disease via lymphoscintigraphy-guided neck dissection in N0 oral squamous cell carcinoma

BACKGROUND

The purpose of this study is to assess the efficacy of lymphoscintigraphy-guided neck dissection (LSG-ND) in the treatment of N0 oral squamous cell carcinoma.

METHODS

A retrospective cohort study of patients with N0 oral squamous cell carcinoma (SCC) who had either LSG-ND or neck dissection (ND) at our institution between 2008 and 2020.

RESULTS

Eighty-seven patients met criteria with N0 oral squamous cell carcinoma with no previous treatment or neck surgery (27 LSG-ND, 60 ND). Sentinel lymph nodes were identified on the contralateral side in 14.8% of patients with unilateral tumors in the LSG-ND group, with 22.2% of cases with unexpected lymphatic drainage outside ipsilateral levels I-III. No recurrences to date have occurred in the LSG-ND cohort, while 13.3% of patients with ND had regional recurrence (p = 0.04).

CONCLUSIONS

LSG-ND provides a greater ability to identify occult metastatic disease with a significant reduction in regional recurrence in N0 oral SCC.

Supraclavicular lymph node recurrence after radical surgery: is epidermal growth factor receptor a predictive marker?

The aim of this study was to evaluate the rare postoperative supraclavicular metastasis originating from oral squamous cell carcinoma (OSCC) and to discuss epidermal growth factor receptor (EGFR) as a potential predictive marker. Tumour specimens of OSCC patients divided into three groups were included: supraclavicular metastasis (n = 8), conventional cervical metastasis (n = 28), no metastasis (n = 48). Basic information and EGFR expression were compared among these groups and the data were analysed to identify potentially related risk factors for supraclavicular metastasis. In the supraclavicular metastasis group (n = 8), all primary tumours were T1-T2 and located in the tongue and buccal region; five of eight cases were pathologically N0. The median interval from the primary tumour resection to the development of supraclavicular metastases was 21.5 months. All related deaths (5/8) occurred within 2 years. In the supraclavicular metastasis group, EGFR expression was highest in the supraclavicular metastases, followed by cervical lymph nodes, and was lowest in the primary tumours (P = 0.39). In contrast, in the conventional metastasis group and the N0 group, EGFR expression was higher in the primary tumours than in the lymph nodes (P < 0.01). Supraclavicular metastasis of OSCC is infrequent and associated with a poor prognosis. EGFR might predict the occurrence of supraclavicular metastasis.

Single-photon emission computed tomography (SPECT/CT) images of sentinel node distribution in oral cancer

This audit describes the lymphatic flow from oral tumours seen on single-photon emission computed tomography (SPECT/CT) to help sentinel node (SN) identification. A total of 95 consecutive sentinel node biopsies (SNB) were taken between 2010 and 2019. Eligibility criteria for SNB were patients over 18 years of age with a T₁-T₂ oral or oropharyngeal squamous cell carcinoma and an N₀ neck. SNs collect at high-frequency sites irrespective of the primary tumour (22.7% level Ib; 64.8% levels II/III; and 7.6% level IV), but with individual variation. Radiotracer activity did not influence the number of nodes identified, and metastatic deposits were found in the hottest nodes. SNs occur at the same high-frequency locations in the neck, so familiarity with anatomical detail may reduce false-negative results.

Sentinel Lymph Node Biopsy in Early Stages of Oral Squamous Cell Carcinoma Using the Receptor-Targeted Radiotracer 99mTc-Tilmanocept

Neck management in patients with early-stage, clinically node-negative oral squamous cell carcinoma (OSCC) remains a matter of discussion. Sentinel lymph node biopsy (SLNB) represents a treatment alternative to avoid elective neck dissection (END) in this cohort and different protocols and tracers exist. Here we present the clinical outcome of SLNB using ^99mTc-tilmanocept in a two-day protocol in patients suffering from early-stage OSCC. A total of 13 patients (males: 6; females: 7; mean age: 65.7 years, ranging from 47 to 89 years) were included in this study. Most of the patients suffered from an OSCC of the floor of mouth (n = 6), followed by tongue (n = 5) and upper alveolar crest/hard palate (n = 2). Sentinel lymph nodes (SLNs) were successfully identified in all cases (range: 1–7). The average length of hospital stay was 4.7 days (range: 3–8 days) and mean duration of surgical intervention was 121 min (range: 74–233 min). One patient who suffered from an OSCC of the tongue was sentinel lymph node positive (SLN+). The mean follow-up for all sentinel lymph node negative (SLN-) patients (n = 12) was 20.3 months (range: 10–28 months). No local or nodal recurrences were observed within the observation period. In our patient cohort, SLNB using ^99mTc-tilmanocept in a two-day protocol proved to be a reliable and safe staging method for patients suffering from early-stage, clinically node-negative OSCC. These results and their possible superiority to colloid tracers have to be confirmed in a prospective randomized controlled study.

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.

MR lymphography with superparamagnetic iron oxide for sentinel lymph node mapping of N0 early oral cancer: A pilot study

OBJECTIVES

The purpose of this pilot study was to evaluate the usefulness of magnetic resonance lymphography (MRL) with superparamagnetic iron oxide (SPIO) in sentinel lymph node (SLN) mapping of clinically N0 early oral cancer, and to conduct a comparative study of this MRL with CT lymphography (CTL).

METHODS

CTL and MRL were performed for SLN mapping before surgery for 20 patients with clinically N0 early oral cancer. The detection rate, number, and location of SLNs in CTL and MRL were evaluated. Furthermore, optimal scanning/imaging timing in MRL was examined.

RESULTS

SLNs were detected by CTL in 18 (90%) patients, and the total and mean number of SLN were 35 and 1.8, respectively. All SLNs could be detected 2 min and 3.5-5 min after contrast medium injection. In all patients, SLNs were detected by MRL at 10 min after SPIO injection, and the total and mean number of SLN was 53 and 2.7, respectively. MRL at 30 min after the injection showed additional 18 secondary lymph nodes.

CONCLUSION

MRL with SPIO is safe and useful imaging for the detection of SLNs in clinically N0 early oral cancer, and the optimal imaging timing is 10 min after SPIO injection.

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.

Effect of Tracer Staining Technology Based on Nano-Carbon Suspension on Patients with Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma has the characteristics of high malignancy, strong invasiveness and special anatomical location. The prognosis of patients is generally poor. Invasion and metastasis of oral squamous cell carcinoma is a complex process involving multiple levels and factors. In order to explore the value of sentinel lymph node biopsy tracked by nano-carbon suspension in the treatment of early oral squamous cell carcinoma, 58 patients with early oral squamous cell carcinoma were selected in this paper. The pathological results of sentinel lymph nodes were analyzed after operation. In this study, the detection rate, sensitivity, accuracy, and false negative rate of the sentinel lymph nodes with the nano-carbon suspension were 95.6%, 86.4%, 92.2%, and 11.4%, respectively. The results show that sentinel lymph node biopsy traced by nano-carbon suspension has certain application value in guiding the treatment of early oral squamous cell carcinoma.

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.

Activation of T helper cells in sentinel node predicts poor prognosis in oral squamous cell carcinoma

Recurrence in oral squamous cell carcinoma (OSCC) significantly reduces overall survival. Improved understanding of the host’s immune status in head and neck cancer may facilitate identification of patients at higher risk of recurrence and improve patients’ selection for ongoing clinical trials assessing the effectiveness of immune checkpoint inhibitors (CPI). We aimed to investigate Sentinel Node-derived T-cells and their impact on survival. We enrolled prospectively 28 OSCC patients treated at Karolinska University Hospital, Stockholm, Sweden with primary tumour excision and elective neck dissection. On top of the standard treatment, the enrolled patients underwent sentinel node procedure. T cells derived from Sentinel nodes, non-sentinel nodes, primary tumour and PBMC were analyzed in flow cytometry. Patients who developed recurrence proved to have significantly lower level of CD4+ CD69+ in their sentinel node (31.38 ± 6.019% vs. 43.44 ± 15.33%, p = 0.0103) and significantly higher level of CD8+ CD HLA-DR+ (38.95 ± 9.479% vs. 24.58 ± 11.36%, p = 0.0116) compared to disease-free individuals. Survival analysis of studied population revealed that patients with low proportion of CD4+ CD69+ had significantly decreased disease-free survival (DFS) of 19.7 months (95% CI 12.6–26.9) compared with 42.6 months (95% CI 40.1–45.1) in those with high CD4+ CD69+ proportion in their Sentinel Nodes (log-rank test, p = 0.033). Our findings demonstrate that characterization of T-cell activation in Sentinel Node serves as a complementary prognostic marker. Flow cytometry of Sentinel Node may be useful in both patients’ surveillance and selection for ongoing CPI clinical trials in head and neck cancer.

Nodal yield and topography of nodal metastases from oral cavity squamous cell carcinoma - An audit of 1004 cases undergoing primary surgical resection

OBJECTIVES

Nodal metastasis is an important prognostic factor in oral squamous cell carcinoma (OSCC). Detailed topographic study of metastasis can guide surgical and adjuvant radiation treatment protocols.

METHODS

Retrospective analysis of distribution of nodal spread was done by auditing pathology records of 1004 patients who underwent primary surgical management at our center.

RESULTS

The median nodal yield was 41 (range of 9-166) nodes, per patient. Metastasis was present in 42.9% patients, of which 52.3% demonstrated extranodal extension. Reclassification by AJCC8 criteria resulted in up-staging in 35.6% patients (pN1, pN2a, pN2b, pN2c, pN3a and pN3b in 13.1%, 3.7%, 6.9%, 0.9%, 0%, 18.1% respectively). Ipsilateral levels Ib and IIa were involved in a quarter of patients each, while IIb, IV and V were involved in < 4%, 3% and 1% of patients, respectively. Contralateral nodal metastasis was present in 5.4%. Skip metastases to level IV were 2.2% and 1.2% for tongue and gingivobuccal primaries. Tongue primaries had a lower likelihood of involving level Ib, but higher of level IIa and III, compared to gingivobuccal primaries, and a lower likelihood of extranodal extension. Primary site did not influence nodal metastasis to levels IIb, IV or V, but other factors like lymphovascular invasion, pT stage and margin status had an influence.

CONCLUSION

This large series with high nodal yield, shows low level of metastasis to level IIb, IV and V, which can help modify future guidelines for extent of surgery and avoid targeted adjuvant radiation to specific levels.

FDG-PET/CT and Pathology in Newly Diagnosed Head and Neck Cancer: ACRIN 6685 Trial, FDG-PET/CT cN0

OBJECTIVE

FDG-PET/CT (fluorodeoxyglucose-positron emission tomography/computed tomography) is effective to assess for occult neck nodal disease. We report risks and patterns of nodal disease based on primary site and nodal level from data on the dissected cN0 per the results from ACRIN 6685.

STUDY DESIGN

Prospective nonrandomized enrollment included participants with first-time head and neck squamous cell carcinoma and at least 1 cN0 neck side to be dissected.

SETTING

Twenty-four ACRIN-certified centers internationally (American College of Radiology Imaging Network).

METHODS

A total of 287 participants were enrolled. Preoperative FDG-PET/CT findings were centrally reviewed and compared with pathology. Incidence, relative risk, pattern of lymph node involvement, and impact upon neck dissection were reported.

RESULTS

An overall 983 nodal levels were dissected (n = 261 necks, n = 203 participants). The highest percentages of ipsilateral positive nodes by primary location and nodal level were oral cavity (level I, 17/110, 15.5%), pharynx (level II, 6/30, 20.0%), and larynx (level VI, 1/3, 33.3%).

CONCLUSION

Levels at greatest risk for nodal disease in cN0 in terms of ipsilateral neck dissection are level I (oral cavity), II (pharynx), and VI (larynx). These data should be considered when treating patients presenting with cN0. This is the first study to comprehensively report the incidence, location, and risk of metastases in cN0 in the FDG-PET/CT era.

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.

Sentinel lymph node mapping of clinically N0 early oral cancer: a diagnostic pitfall on CT lymphography

OBJECTIVE

The purpose of this study was to reevaluate preoperative computed tomography lymphography (CTL) and enhanced CT images during follow-up to clarify whether SLNs enhanced by CTL were identified accurately before primary surgery with sentinel lymph node biopsy (SLNB) for clinically N0 early oral cancer.

METHODS

Thirty two early oral cancer patients without cervical lymph node metastasis were enrolled in this study. To clarify whether SLNs enhanced by CTL were identified accurately before primary surgery with SLNB, we reevaluated preoperative CTL and enhanced CT images during follow-up in all patients.

RESULTS

SLNs were detected by CTL in 31 of 32 patients (96.9%). During follow-up after primary surgery with SLNB, 4 of 27 patients without SLN metastasis had occult neck metastasis. Of the 4 patients, only 1 patient with cancer of floor of the mouth had overlooking of SLN, and the overlooking rate of SLN was 3.1%. The overlooked small SLN (2.9 × 3.3 × 3.1 mm) was located at contralateral level IB. The CT numbers before, 2, 5, 10 min after iopamidol injection, were 33 HU, 37 HU, 62 HU, 52 HU, respectively. The CT numbers of overlooked SLN 5 and 10 min after the injection was higher than CT images scanned before the iopamidol injection.

CONCLUSIONS

The enhancement of SLNs in CTL images after iopamidol injection should be compared sufficiently with CT images before iopamidol injection to avoid overlooking of SLNs in N0 early oral cancer.

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.

CT lymphography for sentinel lymph node mapping of clinically N0 early oral cancer

BACKGROUND

The objectives of this retrospective study were to evaluate the usefulness of computed tomography lymphography (CTL) and to clarify the optimal timing of CTL in sentinel lymph node (SLN) mapping of clinically N0 early oral cancer.

METHODS

Twenty patients with clinically N0 early oral cancer underwent CTL with a 128 multi-detector row CT scanner to detect SLN the day before resection of primary tumor and SLN biopsy with indocyanine green (ICG) fluorescence guidance. CT scanning was performed in the first 10 patients at 2, 5, and 10 min after submucosal injection of iopamidol and in the remaining 10 patients at 2, 3.5, 5, and 10 min after the injection of contrast medium. We evaluated the SLN detection rate at each scan timing and the number and location of SLNs. We evaluated whether CTL-enhanced SLNs could be identified intraoperatively as ICG fluorescent lymph nodes.

RESULTS

SLNs were detected by CTL in 19 of the 20 patients (95.0%), and the mean number of SLNs was 2 (range, 1-4). All SLNs were located on the ipsilateral side; 35 of 37 SLNs were located at level I and II, and 2 SLNs were lingual lymph nodes. All SLNs could be detected 2 min and 3.5-5 min after contrast medium injection, and CTL-enhanced SLNs could be identified intraoperatively as fluorescent lymph nodes.

CONCLUSIONS

CTL could facilitate the detection of SLNs in early oral cancer, and the optimal timing of CT scanning was at 2 and 5 min after injection of contrast medium.

Nanotechnology in Oral Cavity Carcinoma: Recent Trends and Treatment Opportunities

Oral cavity carcinoma (OCC) remains an ongoing public health problem. Emerging nanotechnology provides alternative treatment approaches. This review covers the up-to-date literature in the human OCC treatment field. We explored the growing body of evidence to reveal novel and highly promising diagnostic and therapeutic applications of nanotechnology in this field. Various types of nanoparticles have been tested for applications in OCC. Imaging modalities in addition to nanocarriers are discussed. The encouraging contribution of lymphotropic nanoparticles contrast in the diagnosis of metastatic cervical lymph nodes needs to be confirmed. The development of the sentinel lymph node procedure and photodynamic therapy may lead to breakthrough therapies in order improve clinical outcomes and quality of life. In this perspective, cancer nanotechnology has the potential to revolutionize the treatment of OCC patients.