Sentinel lymph node radiolocalization with 99mTc filtered tin colloid in clinically node-negative squamous cell carcinomas of the oral cavity

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.

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.

Efficacy of postoperative neck irradiation for regional control in patients with pN0 oral tongue cancer: Propensity analysis

BACKGROUND

The purpose of this study was to investigate whether adjuvant radiotherapy (RT) is efficacious for regional control and survival in patients with pN0 oral tongue cancer.

METHODS

Clinicopathological features of 166 patients with pN0 oral tongue cancer were compared between those who underwent adjuvant RT to the neck (neck RT-positive) and those who did not (neck RT-negative). Study endpoints were isolated regional recurrence and 3-year regional recurrence-free survival (RRFS). Propensity score matching was also performed.

RESULTS

Cox regression analysis did not reveal any significant predictor of isolated regional recurrence, including RT field. Three-year RRFS showed modest improvement in neck RT-positive group compared to neck RT-negative group before (92.2% vs 91.9%) and after propensity analysis (93.8% vs 83.3%), without statistical significance (log-rank P = .85 and .37, respectively).

CONCLUSION

Despite more frequent unfavorable factors, the neck RT-positive group had a comparable oncologic outcome to the neck RT-negative group, suggesting that a marginal benefit in regional control might be expected from extending the RT field to the neck for pN0 oral tongue cancer.

Diagnostic value of sentinel lymph node biopsy for cT1/T2N0 tongue squamous cell carcinoma: a meta-analysis

The aim of this study was to systematically evaluate the diagnostic value of the sentinel lymph node biopsy (SLNB) for cT1/T2N0 tongue squamous cell carcinoma (TSCC) patients. A comprehensive and systematic literature review was performed by searching the Embase and PubMed databases for English language articles published up to December 2016. The pooled overall sentinel lymph node (SLN) detection rate, sensitivity and negative predictive value (NPV) were used to evaluate the diagnostic value of SLNB which used neck dissection or follow-up as a reference test. The Q test and I ² statistic were used to assess the heterogeneity across the studies. Subgroup analyses were performed in consideration of higher contribution of different clinical characteristics on the SLNB diagnostic value. Begg's linear regression and Egger's regression tests were conducted to evaluate the publication bias. Thirty-five studies (with 1084 patients) were included. The pooled SLN detection rate was 98% (95% CI 97-100%). The pooled overall sensitivity and NPV of SLNB were 0.92 (95% CI 0.88-0.95) and 0.96 (95% CI 0.94-0.97), respectively. The subgroup analyses demonstrated that higher extracted number of patients (n ≥ 30) from the included studies achieved a more stable NPV than lower number of patients. SLNB can effectively predict the status of regional lymph nodes in cT1/T2N0 TSCC patients. With high sensitivity and NPV, SLNB can guide the treatment of SLNB-positive patients with neck dissections and those with negative SLNBs with follow-ups in order to avoid unnecessary surgical morbidity.

Diagnostic Efficacy of Sentinel Lymph Node Biopsy in Early Oral Squamous Cell Carcinoma: A Meta-Analysis of 66 Studies

OBJECTIVES

The diagnostic efficacy of sentinel lymph node biopsy(SLNB) in early oral squamous cell carcinoma(OSCC) still remains controversial. This meta-analysis was conducted to assess the diagnostic value of SLNB in clinically neck-negative T1-2 OSCC.

METHODS

A systematic literature search for relevant literature published up to September 11, 2016 was conducted in PubMed, Embase, Web of Science, Cochrane Library and ClinicalTrials, and the reference lists of eligible studies were examined. Data from different studies were pooled to estimate the summary sentinel lymph node(SLN) identification rate, sensitivity, negative predictive value. Summary receiver operator characteristic curve(SROC) was plotted and area under the SROC curve (AUC) was calculated to evaluate the overall diagnostic efficacy. Threshold effect was assessed with use of the spearman correlation coefficient. Between-study heterogeneity was tested using the Q tests and the I2 statistics. Subgroup analyses were conducted in view of the greater effect of different study characteristics on diagnostic efficacy of SLN. Deeks' funnel plot asymmetry test was performed to evaluate publication bias. Sensitivity analysis was evaluated through omitting studies one by one and comparing the pooled results of random-effects model and fixed-effects model. All analyses were performed using Review Manager (version 5.3.5), Meta-DiSc (version 1.4), Comprehensive Meta Analysis (version 2.0) and STATA (version 12).

RESULTS

66 studies comprising 3566 patients with cT1-2N0 OSCC were included in this meta-analysis. The pooled SLN identification rate was 96.3%(95% CI: 95.3%-97.0%). The pooled sensitivity was 0.87 (95% CI: 0.85-0.89), pooled negative predictive value was 0.94 (95% CI: 0.93-0.95), and AUC was 0.98 (95% CI: 0.97-0.99). Subgroup analyses indicated that SLN assessment with immunohistochemistry(IHC) achieved a significantly higher sensitivity than without IHC.

CONCLUSIONS

This meta-analysis suggests that SLNB has a high diagnostic accuracy in cT1-2N0 oral squamous cell carcinoma, and is an ideal alternative to elective neck dissection. Furthermore, the use of IHC can significantly improve SLNB diagnostic sensitivity for early OSCC.

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

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

Comparative study of sentinel lymph node biopsy in clinically N0 oral tongue squamous cell carcinoma: Long-term oncologic outcomes between validation and application phases

OBJECTIVE

This study tested the long-term outcomes of sentinel lymph node biopsy (SLNB) for oral tongue squamous cell carcinoma (SCC) during the transition from validation to application phase.

MATERIALS AND METHODS

Sensitivity, negative predictive value (NPV), neck control rate, disease-specific survival (DSS), disease-free survival (DFS), and overall survival (OS) were compared in cN0 oral tongue SCC patients from different phases.

RESULTS

A total of 133 SLNs from 61 patients (21 in the validation phase, 40 in the application phase) were harvested. Fourteen SLNs of 12 patients (6 in each phase) were positive for metastasis (occult metastasis rate, 19.6%). Regional recurrences developed from 5 negative SLNs (one in the validation phase, 4 in the application phase), of whom 3 patients were successfully salvaged. Sensitivity and NPV of the validation phase were both 100%, with 60.0% and 88.2% in the application phase. False omission rates were 6.6% (1/15) in the validation group, and 11.7% (4/34) in the application group, respectively. The neck control rate was 95.2% in the validation phase and 97.5% in the application phase (p=0.52). No differences were evident in DSS, DFS, and OS between the two phases (DSS: 92.5% vs 95.2%, p=0.69; DFS: 85.0% vs 90.4%, p=0.40; OS: 90% vs 85.5%, p=0.62). Subgroup analyses between negative- and positive-SLNs within each phase revealed no significant differences in all endpoints.

CONCLUSION

Given higher false negative cases in the application phase, stringent strategy of follow-up and salvage treatment is mandatory to maintain acceptable outcomes.

Freehand SPECT for sentinel lymph node detection in patients with head and neck cancer: first experiences

CONCLUSION

Feasibility of intraoperative 3D imaging with freehand (fh) SPECT for sentinel lymph node (SLN) biopsy in head and neck cancer (HNC) could be demonstrated. Controlled clinical studies are needed to evaluate its accuracy and impact on patient morbidity.

OBJECTIVES

The clinical N0 neck in HNC needs improvement in management to sufficiently detect occult neck disease but to spare patients from potential morbidity by elective neck dissection. The SLN concept has potential to accurately stage the neck with low morbidity.

METHODS

fhSPECT is a 3D tomographic imaging modality with a gamma probe system combined with an infrared optical tracking system. Five patients with HNC and clinical N0 neck were recruited. Scanning for SLN using fhSPECT was performed before excision and selective neck dissection and specimens were analyzed histopathologically.

RESULTS

Preoperatively, a total of nine SLNs were located in five patients with fhSPECT. SLNs in three patients were positive for metastatic disease; in two patients the SLNs were tumor-free. No residual radioactivity was found in the neck in any of the patients after extirpation of SLNs. fhSPECT acquisitions took 2.6 ± 0.4 min. No metastatic lymph nodes were detected in any other node harvested during subsequent selective neck dissection in any patients.

Diagnostic value of sentinel lymph node biopsy in head and neck cancer: a meta-analysis

This study aimed to evaluate the diagnostic reliability of sentinel lymph node biopsy in patients with squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, and larynx by reviewing the published literature. A systematic literature review was performed using MEDLINE from 1970 to 2011. With Boolean search strings, search terms included sentinel node, supraglottic, supraglottis, tongue, head and neck, oral, pharynx, laryngeal, and larynx. Additional studies were identified through article references. Duplicate data and articles were excluded based on treating institution and study inclusion time period. Additional studies were excluded if the head and neck subsite or tumor stage was not specifically identified or if the sentinel lymph node biopsy occurred in previously treated necks. All patients had sentinel lymph node biopsy performed followed by a concurrent neck dissection. Twenty-six studies met our inclusion criteria (n = 766 patients). The pooled sensitivity and negative predictive value of SLNB for all head and neck tumors was 95 % (95 % CI 91-99 %) and 96 % (95 %CI 94-99 %), respectively. The overall sensitivity and negative predictive value of SLNB in the subset of oral cavity tumors (n = 631) was 94 % (95 % CI 89-98 %) and 96 % (95 % CI 93-99 %), respectively. One-hundred percent of oropharyngeal (n = 72), hypopharyngeal (n = 5), and laryngeal (n = 58) tumor sentinel lymph biopsy results correlated with subsequent neck dissections giving a negative predictive value of 100 %, showing that, sentinel lymph node biopsy is a valid diagnostic technique to correctly stage regional metastases in patients with head and neck squamous cell carcinoma.

Lymphatic vessels and high endothelial venules are increased in the sentinel lymph nodes of patients with oral squamous cell carcinoma before the arrival of tumor cells

PURPOSE

To investigate the change of vasculature in the sentinel lymph node (SLN) of patients with oral squamous cell carcinoma.

METHODS

Immunohistochemical staining of SLNs in 58 patients was performed with two monoclonal antibodies (MAb): anti-D2-40 MAb for lymphatic endothelial cells, and anti-MECA-79 MAb for high endothelial venules (HEV). Twelve metastatically involved (m(+)) SLNs, 120 uninvolved (m(-)) SLNs, and 35 non-SLNs (control) were available for analyses. Vessel densities were measured by computer-assisted analyses in the entire region of SLN. Correlations were assessed between vessel density and clinicopathologic variables, including vascular endothelial growth factor C of primary tumor.

RESULTS

Lymphatic vessel density (LVD) in SLNs was higher than that in control LNs [2361.8 μm(2)/high-power field (HPF) (624.3-4758.5) vs. 1621.9 μm(2)/HPF (465.3-3453.5), P = 0.005]. LVD of m(-) SLNs [2662.4 μm(2)/HPF (624.3-4758.5)] and m(±) SLNs [4946.6 μm(2)/HPF (2009.3-8698.8)] were both statistically significantly higher compared to control. HEV densities in m(-) SLNs [14029.7 μm(2)/HPF (10465.7-17927.1)] as well as m(±) SLNs [18258.5 μm(2)/HPF (8408.9-27706.0)] were also significantly higher than those in control [10350.5 μm(2)/HPF (7807.8-12541.1)]. By multivariate analysis, the degree of vascular endothelial growth factor C expression of primary tumor showed significant correlation with LVD of SLNs (odds ratio 9.46, 95% confidence interval 1.73-51.5, P = 0.009), which was not the case in HEV.

CONCLUSIONS

Lymphatic vessels and HEVs were increased in SLNs, regardless of metastatic status of SLNs. Vascular endothelial growth factor C expression of primary tumor may contribute to the premetastatic change within SLNs of oral squamous cell carcinoma.

The feasibility of sentinel lymph node biopsy with a multidisciplinary cooperative team approach for the management of koreans with cutaneous malignant melanoma

BACKGROUND

The regional lymph nodal status is the most powerful independent predictor of survival for patients with clinical N0 primary cutaneous malignant melanoma.

OBJECTIVE

We wanted to evaluate the feasibility and morbidity of the sentinel lymph node biopsy (SLNB) staging using a multidisciplinary team approach, in cooperation with other surgical departments, at a university hospital setting.

METHODS

Twenty two patients with cutaneous melanoma and who were treated at Kyungpook National University Hospital were included in this study. They all received SLNB, which was done by the Departments of Dermatology and General Surgery. We evaluated the feasibility and side effects of SLNB.

RESULTS

Pathologically-positive sentinel nodes were found in 7 of the 22 cases (31.8%) and all 7 patients were consequently upstaged. The whole process involved in SLNB was well tolerated by nearly all the patients, with only mild and transient complications being observed.

CONCLUSION

We suggest that in a Korean setting, utilizing SLNB with a multi-disciplinary team approach is a technically feasible procedure that is able to detect occult nodal metastasis with low morbidity rates in patients with cutaneous malignant melanoma.