Visualization of the sentinel node in early-stage oral cancer: limited value of late static lymphoscintigraphy

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.

Within-patient comparison between [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy and [99mTc]Tc-tilmanocept lymphoscintigraphy for sentinel lymph node detection in oral cancer: a pilot study

PURPOSE

To compare sentinel lymph node (SLN) identification using [⁶⁸Ga]Ga-tilmanocept PET/CT lymphoscintigraphy to [^99mTc]Tc-tilmanocept lymphoscintigraphy (including SPECT/CT) in early-stage oral cancer. Furthermore, to assess whether reliable intraoperative SLN localization can be performed with a conventional portable gamma-probe using [^99mTc]Tc-tilmanocept without the interference of [⁶⁸Ga]Ga-tilmanocept in these patients.

METHODS

This prospective within-patient comparison pilot study evaluated SLN identification by [⁶⁸Ga]Ga-tilmanocept PET/CT lymphoscintigraphy compared to conventional lymphoscintigraphy using [^99mTc]Tc-tilmanocept (~ 74 MBq) in 10 early-stage oral cancer patients scheduled for SLN biopsy. After conventional [^99mTc]Tc-tilmanocept lymphoscintigraphy, patients underwent peritumoral administration of [⁶⁸Ga]Ga-tilmanocept (~ 10 MBq) followed by PET/CT acquisition initiated 15 min after injection. Intraoperative SLN localization was performed under conventional portable gamma-probe guidance the next day; the location of harvested SLNs was correlated to both lymphoscintigraphic images in each patient.

RESULTS

A total of 24 SLNs were identified by [^99mTc]Tc-tilmanocept lymphoscintigraphy, all except one were also identified by [⁶⁸Ga]Ga-tilmanocept PET/CT lymphoscintigraphy. [⁶⁸Ga]Ga-tilmanocept PET/CT lymphoscintigraphy identified 4 additional SLNs near the injection site, of which two harbored metastases. Lymphatic vessels transporting [⁶⁸Ga]Ga-tilmanocept were identified by PET/CT lymphoscintigraphy in 80% of patients, while draining lymphatic vessels were visualized by [^99mTc]Tc-tilmanocept lymphoscintigraphy in 20% of patients. Of the 33 SLNs identified by [⁶⁸Ga]Ga-tilmanocept PET/CT lymphoscintigraphy, 30 (91%) were intraoperatively localized under conventional gamma-probe guidance.

CONCLUSION

[⁶⁸Ga]Ga-tilmanocept PET/CT lymphoscintigraphy provided more accurate identification of SLNs and improved visualization of lymphatic vessels compared to [^99mTc]Tc-tilmanocept lymphoscintigraphy. When combined with peritumoral administration of [^99mTc]Tc-tilmanocept, SLNs detected by [⁶⁸Ga]Ga-tilmanocept PET/CT lymphoscintigraphy can be reliably localized during surgery under conventional gamma-probe guidance.

Evaluation of a streamlined sentinel lymph-node imaging protocol in early-stage oral cancer

OBJECTIVE

Sentinel lymph-node (SLN) mapping for early-stage oral squamous cell carcinoma (OSCC) is comprehensive and consequently time-consuming and costly. This study evaluated the clinical value of several SLN imaging components and analyzed the accuracy for SLN identification using a streamlined SLN imaging protocol in early-stage OSCC.

MATERIALS AND METHODS

This retrospective within-patient evaluation study compared both number and localization of identified SLNs between the conventional SLN imaging protocol and a streamlined imaging protocol (dynamic lymphoscintigraphy (LSG) for 10 min directly post-injection and SPECT-CT at ~ 2 h post-injection). LSG and SPECT-CT images of 77 early-stage OSCC patients, scheduled for SLN biopsy, were evaluated by three observers. Identified SLNs using either protocol were related to histopathological assessment of harvested SLNs, complementary neck dissection specimens and follow-up status.

RESULTS

A total of 200 SLNs were identified using the streamlined protocol, and 12 additional SLNs (n = 212) were identified with the conventional protocol in 10 patients. Of those, 9/12 were identified on early static LSG and 3/12 on late static LSG. None of the additionally identified SLNs contained metastases; none of those in whom additional SLNs were identified developed regional recurrence during follow-up. Only inferior alveolar process carcinoma showed a higher rate of additionally identified SLNs with the conventional protocol (p = 0.006).

CONCLUSION

Early dynamic LSG can be reduced to 10 min. Late static LSG may be omitted, except in those with a history of oncological neck treatment or with OSCC featuring slow lymphatic drainage. Early static LSG appeared to be contributory in most OSCC subsites.

Radioguided sentinel node biopsy to avoid unnecessary neck dissection in T1-T2N0 oral cavity squamous cell carcinoma: personal experience with same day protocol

PURPOSE

Data from literature show a mean incidence of occult metastases of 33% in early OCSCC. The gold standard for most authors is a selective neck dissection and a routine pathological examination. 60-70% of unnecessary neck dissections with associated morbidity, can be avoided by using SNB. The aim of this study is to present the results of one of the major Italian centres for the SNB procedure, reserving neck dissection only for proven positive lymphatic metastases.

METHODS

From July 2004 to March 2015, 48 patients with transorally resectable cT1-T2N0 oral SCC were submitted to a lymphoscintigraphic examination one-three hours before surgery and a radio-guided SNB (same day protocol). Patients with a negative SNB were checked every 3 months by ultrasound examination. The minimum follow-up was 5 years.

RESULTS

Sentinel nodes were found in all cases, with 71% localized in the ipsilateral neck only in levels I-II. Metastases were found in 15 out of 48 cases (31.2%), on levels I, II and III. Further metastatic nodes were found in 6 cases in the neck dissection specimen. In the cohort of 33 patients with SNB negative at 5 years, no-one had a recurrence on the ipsilateral neck.

CONCLUSION

This study confirms the accuracy of SNB in predicting the presence of occult metastases, sparing the need for unnecessary neck dissection in 70% of cases. The same day protocol is designed to detect sentinel nodes, which are almost always on neck level I-II, thereby limiting the number of nodes examined and the extension of the surgical approach.

Usefulness of Sentinel Lymph Node Biopsy for Oral Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

We assessed the diagnostic accuracy of sentinel lymph node biopsy (SLNB) for detecting neck nodal metastasis in early oral squamous cell carcinoma (OSCC) as an alternative to elective neck dissection.

STUDY DESIGN

A systematic search for relevant literature was conducted in the PubMed, SCOPUS, Embase, Web of Science, and Cochrane databases.

METHODS

Two reviewers individually searched the five databases up to November 2019. For studies that met inclusion criteria, data on patient diagnoses were pooled, including true positives, true negatives, false positives, and false negatives. Methodological quality was checked with the Quality Assessment of Diagnostic Accuracy Studies (version 2) tool.

RESULTS

In total, 98 observational or retrospective studies were included. The diagnostic odds ratio of SLNB was 326.165 (95% confidence interval [CI]: 231.477-459.587; I²  = 0%). The area under the summary receiver operating characteristic curve was 0.982. Sensitivity was 0.827 (95% CI: 0.804-0.848), and specificity was 0.981 (95% CI: 0.975-0.986). The correlation between sensitivity and the false positive rate was -0.076, which indicates that heterogeneity did not exist. Subgroup analyses were performed with the subgroups reference test type, publication year, and study type. No significant difference was found within the reference test type subgroup. However, differences within the publication year and study type subgroups were significant, where the retrospective study subgroup was significantly more sensitive and specific than the prospective study subgroup.

CONCLUSION

Results of this meta-analysis imply that the high specificity of SLNB supports its role as a diagnostic tool for patients with clinical tumor stage (CT)1-2 clinically negative (N0) OSCC. More studies should be done to further verify the results of this study.

LEVEL OF EVIDENCE

2a Laryngoscope, 131:E459-E465, 2021.

Sentinel lymph node metastasis in primary cutaneous basosquamous carcinoma. A cross-sectional study

BACKGROUND AND OBJECTIVES

Basosquamous carcinoma (BSC) is a rare, biologically aggressive tumor. This cross-sectional study aims to define risk factors for subclinical nodal metastasis in primary BSC, and identify the patients who would benefit from routine sentinel node biopsy (SLNB) as part of the initial management.

METHODS

A total of 142 patients, with histologically proven BSC without palpable lymph nodes, underwent SLNB after the initial excision. Clinicopathological features and demographics were analyzed between the patients with detected micrometastasis (SLNM) and those with negative SLN.

RESULTS

In 7.7% patients, subcapsular and <0.1 mm SLNM were found. The frequency of SLNM was 0.9%, 11.8%, and 80.0% in patients with maximum lesion diameter ≤ 2 cm, 2.1-3.0 cm and >3.0 cm, respectively (P < 0.001) and was strongly associated with perineural (P < 0.001; OR = 26.46, 95% CI = 5.62-124.52) and lymphatic invasion (P < 0.001; OR = 17.35, 95% CI = 4.44-67.91). Within 18-84 months, no recurrence or metastasis were observed in SLNM positive patients. False negative SLNB rate of 15.4% was recorded.

CONCLUSION

Cutaneous BSC is associated with early nodal metastatic potential. Tumor size >2 cm, lymphatic and perineural invasion are significant determinants for SLN micrometastasis. In the absence of palpable lymphadenopathy, wide resection and SLNB with long-term follow-up are highly recommended in these patients.

The added value of SPECT-CT for the identification of sentinel lymph nodes in early stage oral cancer

PURPOSE

To assess the role of single-photon emission computed tomography with computed tomography (SPECT-CT) for the identification of sentinel lymph nodes (SLNs) in patients with early stage (T1-T2) oral cancer and a clinically negative neck (cN0).

METHODS

In addition to planar lymphoscintigraphy, SPECT-CT was performed in 66 consecutive patients with early stage oral cancer and a clinically negative neck. The addition of SPECT-CT to planar images was retrospectively analyzed for the number of additional SLNs, more precise localization of SLNs, and importance of anatomical information by a team consisting of a nuclear physician, surgeon, and investigator.

RESULTS

Identification rate for both imaging modalities combined was 98% (65/66). SPECT-CT identified 15 additional SLNs in 14 patients (22%). In 2/15 (13%) of these additional SLNs, the only metastasis was found, resulting in an upstaging rate of 3% (2/65). In 20% of the patients with at least one positive SLN, the only positive SLN was detected due to the addition of SPECT-CT. SPECT-CT was considered to add important anatomical information in two patients (3%). In 5/65 (8%) of the patients initially scored SLNs on planar lymphoscintigrams were scored as non-SLNs when SPECT-CT was added. There were four false-negative SLN biopsy procedures in this cohort.

CONCLUSIONS

The addition of SPECT-CT to planar lymphoscintigraphy is recommended for the identification of more (positive) SLNs and better topographical orientation for surgery in sentinel lymph node biopsy for early stage oral cancer.

Sentinel Node in Oral Cancer: The Nuclear Medicine Aspects. A Survey from the Sentinel European Node Trial

PURPOSE

Nuclear imaging plays a crucial role in lymphatic mapping of oral cancer. This evaluation represents a subanalysis of the original multicenter SENT trial data set, involving 434 patients with T1-T2, N0, and M0 oral squamous cell carcinoma. The impact of acquisition techniques, tracer injection timing relative to surgery, and causes of false-negative rate were assessed.

METHODS

Three to 24 hours before surgery, all patients received a dose of Tc-nanocolloid (10-175 MBq), followed by lymphoscintigraphy. According to institutional protocols, all patients underwent preoperative dynamic/static scan and/or SPECT/CT.

RESULTS

Lymphoscintigraphy identified 723 lymphatic basins. 1398 sentinel lymph nodes (SNs) were biopsied (3.2 SN per patient; range, 1-10). Dynamic scan allowed the differentiation of sentinel nodes from second tier lymph nodes. SPECT/CT allowed more accurate anatomical localization and estimated SN depth more efficiently. After pathological examination, 9.9% of the SN excised (138 of 1398 SNs) showed metastases. The first neck level (NL) containing SN+ was NL I in 28.6%, NL IIa in 44.8%, NL IIb in 2.8%, NL III in 17.1%, and NL IV in 6.7% of positive patients. Approximately 96% of positive SNs were localized in the first and second lymphatic basin visualized using lymphoscintigraphy. After neck dissection, the SN+ was the only lymph node containing metastasis in approximately 80% of patients.

CONCLUSIONS

Best results were observed using a dynamic scan in combination with SPECT/CT. A shorter interval between tracer injection, imaging, and surgery resulted in a lower false-negative rate. At least 2 NLs have to be harvested, as this may increase the detection of lymphatic metastases.

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.

Fusion of Freehand SPECT and Ultrasound to Perform Ultrasound-Guided Fine-Needle Aspiration Cytology of Sentinel Nodes in Head and Neck Cancer

BACKGROUND AND PURPOSE

Criteria for ultrasound-guided fine-needle aspiration cytology (USgFNAC) for the detection of occult lymph node metastasis in patients with clinically negative head and neck cancer are based on the morphology of cervical lymph nodes. To improve the selection of lymph nodes for USgFNAC, we examined the feasibility of fused freehand single-photon emission tomography ultrasound-guided fine-needle cytology (freehand SPECT-USgFNAC) of sentinel nodes in patients with early stage oral and head and neck skin cancer.

MATERIALS AND METHODS

Six patients with early-stage head and neck cancer (4 oral and 2 head and neck skin cancers) and a clinically negative neck who were scheduled for transoral or local excision and a sentinel node procedure underwent USgFNAC and freehand SPECT-USgFNAC preoperatively.

RESULTS

All freehand SPECT sonographic examinations were technically successful in terms of identifying sentinel nodes. All aspirates of sentinel nodes obtained by freehand SPECT-USgFNAC contained substantial radioactivity, confirming puncture of the sentinel nodes. USgFNAC evaluated 13 lymph nodes; freehand SPECT-USgFNAC, 19 nodes; and sentinel node biopsy, 13 nodes. Three sentinel nodes were histopathologically positive and were selected for aspiration cytology by freehand SPECT-USgFNAC, but not by conventional ultrasound. The cytologic examination findings of the aspirations were negative or inconclusive.

CONCLUSIONS

Freehand SPECT ultrasound can identify sentinel nodes and could potentially improve USgFNAC in patients with head and neck cancer by better selection of lymph nodes at highest risk of having metastases (sentinel nodes), but its sensitivity is limited by sampling error and insufficient aspirated material for cytology.

Sentinel node biopsy using indocyanine green in oral/oropharyngeal cancer

BACKGROUNDS

Radioactive tracer-based detection has been proposed as a standard procedure in identifying sentinel nodes for cN0 oral/oropharyngeal carcinoma. However, access to radioactive isotopes may be limited in some surgical centers, and there is potential risk of the radioactive tracers to the operators. This study was designed to evaluate the feasibility of near-infrared fluorescence imaging with indocyanine green combined with blue dye mapping in sentinel node biopsy for cN0 oral/oropharyngeal carcinoma.

METHODS

Twenty-six cases of previously untreated oral/oropharyngeal carcinoma staged cT1-2N0M0 were enrolled in this study. One milliliter of indocyanine green (5 mg/ml) and 1.5 ml of methylene blue (1 mg/ml) were injected sequentially around the primary tumor in a four-quadrant pattern before skin incision. After elevation of the platysma flap and posterior retraction of the sternocleidomastoid muscle, fluorescence images were taken with a near-infrared detector, with special attention paid to any blue-dyed lymph nodes. Lymph nodes identified first with fluorescent hot spots with or without blue dye were defined as sentinel nodes, and they were harvested and sent for pathologic study.

RESULTS

Sentinel nodes were successfully harvested in all 26 cases. The number of sentinel nodes (SNs) per case varied from 1 to 9, with an average of 3.4. Routine pathology demonstrated occult metastasis exclusively in SNs in four cases (15.4 %). No tracer-associated side effects occurred in this series.

CONCLUSIONS

Near-infrared imaging using indocyanine green combined with methylene blue mapping is a feasible and reliable new method for SN biopsy in cN0 oral/oropharyngeal carcinoma.

Sentinel lymph node biopsy in oral and oropharyngeal squamous cell carcinoma: current status and unresolved challenges

Because imaging with ultrasound, computed tomography, magnetic resonance imaging or positron emission tomography is unreliable for preoperative lymph node staging of early-stage oral and oropharyngeal squamous cell carcinoma (OSCC), elective neck dissection has been typically performed. The targeted sampling of sentinel lymph nodes (SLN) identified by lymphoscintigraphy and detected by gamma probe has become an effective alternative for the selection of patients for regional nodal resection. With careful consideration to technique, high SLN detection rates have been reported. Advanced techniques including intraoperative handheld gamma camera imaging and freehand single photon emission computed tomography (SPECT) are expected to increase surgical confidence in these procedures. This review gives an update on SLN biopsy in patients with OSCC including clinical standards and controversial aspects.

Lymphatic drainage patterns in oral squamous cell carcinoma: findings of the ACOSOG Z0360 (Alliance) study

OBJECTIVE

The purpose of our study was to correlate sentinel lymph nodes (SLN) found on planar lymphoscintigraphy (LS) to SLN found with gamma probe-directed sentinel lymph node biopsy (SLNB) for T1/T2 N0 oral cavity cancer.

STUDY DESIGN

Prospective cooperative group trial.

SETTING

Academic medical centers.

SUBJECTS AND METHODS

One hundred forty adults with untreated T1/T2 N0 squamous cell carcinoma (SCC) of the oral cavity underwent planar LS, resection, SLNB, and neck dissection. Location of SLN by planar LS and SLNB and of metastases were compared to each other and historical data of regional metastases.

RESULTS

SLNs located by planar LS and SLNB were predominantly in levels I through IV. There was heterogeneity in the number of SLNs found at planar LS and at SLNB, which was significantly different in levels II and III (P < .0001). In 14 of 33 cases with bilateral drainage on planar LS, SLNB detected only unilateral SLN. Sensitivity of planar LS in predicting the level of SLN was 41% to 63%, and specificity was 68% to 95%. Comparison of locations of the metastases to historical data showed fewer metastases to level I in our study (P = .03). Metastases occurred predominantly in levels I through III. In 1 case of a lateral tongue cancer, a contralateral SLN was the only positive node.

CONCLUSION

Lymphatic drainage patterns and metastases involved predominantly levels I through III. Planar LS is not sensitive for predicting the levels of SLN, and in levels II and III, the rate of detection of SLN between the 2 modalities is significantly different.

Advances in diagnostic modalities to detect occult lymph node metastases in head and neck squamous cell carcinoma

Regional metastasis is a prominent feature of head and neck squamous cell carcinoma (HNSCC) and is an important prognostic factor. The currently available imaging techniques for assessment of the neck have limitations in accuracy; thus, elective neck dissection has remained the usual choice of management of the clinically N0 neck (cN0) for tumors with significant (≥20%) incidence of occult regional metastasis. As a consequence, the majority of patients without regional metastasis will undergo unnecessary treatment. The purpose of this review was to discuss new developments in techniques that potentially improve the accuracy of the assessment of the neck in patients with HNSCC. Although imaging has improved in the last decades, a limitation common to all imaging techniques is a lack of sensitivity for small tumor deposits. Therefore, complementary to improvements in imaging techniques, developments in more invasive diagnostic procedures, such as sentinel node biopsy (SNB) will add to the accuracy of diagnostic algorithms for the staging of the neck.

Practice variation in defining sentinel lymph nodes on lymphoscintigrams in oral cancer patients

PURPOSE

Lymphoscintigraphic imaging and adequate interpretation of the lymphatic drainage pattern is an essential step in the sentinel lymph node biopsy (SLNB) procedure. In oral cancer, identification of the sentinel lymph node (SLN) can be challenging. In this study, interobserver variability in defining SLNs on lymphoscintigrams was evaluated in patients with T1-T2 stage N0 oral cancer.

METHODS

Sixteen observers (head and neck surgeons, nuclear medicine physicians or teams of both) from various institutes were asked which criteria they use to consider a hot focus on the lymphoscintigram as SLN. Lymphoscintigrams of 9 patients with 47 hot foci (3-9 per patient) were assessed, using a scale of 'yes/equivocal/no'. Bilateral drainage was seen in four of nine cases. In three cases additional late single photon emission computed tomography (SPECT)/CT scanning was performed. Interobserver variability was evaluated by kappa (к) analysis, using linear weighted pairwise comparison of the observers. Conservative (equivocal analysed as no) and sensitive (equivocal analysed as yes) assessment strategies were investigated using pairwise kappa analysis.

RESULTS

Various definitions of SLN on lymphoscintigrams were given. Interobserver variability of all cases using a 3-point scale showed fair agreement (71%, к(w) = 0.29). The conservative and sensitive analyses both showed moderate agreement: conservative approach к = 0.44 (in 80% of the hot foci the observers agreed) and sensitive approach к = 0.42 (81%) respectively. Multidisciplinary involvement in image interpretation and higher levels of observer experience appeared to increase agreement.

CONCLUSION

Among 16 observers, there is practice variation in defining SLNs on lymphoscintigrams in oral cancer patients. Interobserver variability of lymphoscintigraphic interpretation shows moderate agreement. In order to achieve better agreement in defining SLNs on lymphoscintigrams specific guidelines are warranted.

Sentinel node biopsy for early-stage oral cavity cancer: the VU University Medical Center experience

BACKGROUND

Sentinel node biopsy (SNB) in head and neck cancer is recently introduced as the staging technique of oral squamous cell carcinoma. We report the results of SNB in patients diagnosed with a T1-T2 oral squamous cell carcinoma and clinically negative (N0) neck in a single center.

METHODS

A retrospective analysis of 90 previously untreated patients who underwent SNB between 2007 and 2012 was performed. The SNB procedure consisted of preoperatively performed lymphoscintigraphy, intraoperative detection using blue dye, and gamma probe guidance and histopathologic examination including step-serial sectioning (SSS) and immunohistochemical (IHC) staining. A positive SNB was followed by neck dissection, whereas regular follow-up with ultrasound-guided fine-needle aspiration cytology (FNAC) was done in case of a negative SNB.

RESULTS

The lymphoscintigraphic identification rate was 98% (88 of 90 patients) and the surgical detection rate was 99% (87 of 88 patients). The upstaging rate was 30%. Sensitivity of SNB was 93% and the negative predictive value was 97%. The median follow-up was 18 months (range, 2-62 months). Overall survival (OS) and disease-free survival (DFS) for SNB negative were 100% and 84% and for SNB positive patients 73% and 88%, respectively.

CONCLUSION

SNB is a reliable diagnostic staging technique for the clinically negative neck in patients with early-stage (T1-T2, cN0) oral squamous cell carcinoma.