Joint practice guidelines for radionuclide lymphoscintigraphy for sentinel node localization in oral/oropharyngeal squamous cell carcinoma

[Nuclear medicine procedure guideline for sentinel lymph node localization]

The authors present a procedure guideline for scintigraphic detection of sentinel lymph nodes in malignant melanoma, in breast cancer, in penile and vulva tumors, in head and neck cancer, and in prostate carcinoma. Important goals of sentinel lymph node scintigraphy comprise reduction of the extent of surgery, lower postoperative morbidity and optimization of histopathological examination focussing on relevant lymph nodes. Sentinel lymph node scintigraphy itself does not diagnose tumorous lymph node involvement and is not indicated when lymph node or distant metastases have been definitely diagnosed before sentinel lymph node scintigraphy. Procedures are compiled with the aim to reliably localise sentinel lymph nodes with a high detection rate typically in early tumour stages. New aspects in this guideline are new radiopharmaceuticals such as tilmanocept and Tc-99m-PSMA and SPECT/CT allowing an easier anatomical orientation. Initial dynamic lymphoscintigraphy in breast cancer is of little significance nowadays. Radiation exposure is low so that pregnancy is not a contraindication for sentinel lymph node scintigraphy. A one-day protocol should preferentially be used. Even with high volumes of scintigraphic sentinel lymph node procedures surgeons, theatre staff and pathologists receive a radiation exposure < 1 mSv/year so that they do not require occupational radiation surveillance. Aspects of quality control were included (scintigraphy, quality control of gamma probe, 6 h SLN course for surgeons, certified breast centers, medical surveillance center).

Challenges in Preparation of Albumin Nanoparticle-Based Radiopharmaceuticals

Albumin nanocolloids have been used as radiopharmaceuticals for more than 40 years. Their main use is in lymphoscintigraphy and the detection of the sentinel lymph node as part of the surgical treatment of a variety of solid tumours. The main licensed products are labelled with the gamma emitter technetium-99m. Recently, two analogues labelled with positron emitters have been reported, using gallium-68 and zirconium-89. For about 10 years, there has been interest in dual-modal agents with both radioactive and fluorescent labels to improve the localisation of the sentinel lymph node. Indocyanine green (ICG) has been the most widely used fluorescent label, largely due to its availability as a licensed agent and its ease of application. The further development of alternative radiolabels or improved fluorescent tags will require investment in the development and licensing. There is also a vast potential for the targeting of albumin nanocolloids using existing strategies, which could be promising for the development of both diagnostic and therapeutic agents.

Detecting cancer metastasis and accompanying protein biomarkers at single cell levels using a 3D-printed microfluidic immunoarray

A low-cost microfluidic microarray capable of lysing cells and quantifying proteins released after lysis was designed and 3D-printed. The array lyses cells on-chip in lysis buffer augmented with a 2s pulse of a sonic cell disruptor. Detection of desmoglein 3 (DSG3), a metastatic biomarker for head and neck squamous cell carcinoma (HNSCC), along with two accompanying HNSCC biomarkers from a single cell lysate of oral cancer cell cultures was demonstrated. A lysis chamber and reagent compartments deliver sample and reagents into detection chambers decorated with capture antibodies immobilized onto inner walls coated with a highly swollen 3D chitosan hydrogel film. Sandwich immunoassays are achieved when captured analytes labeled with biotinylated secondary antibodies, which then capture streptavidin-poly [horse radish peroxidase] (Poly-HRP). Subsequent delivery of super-bright femto-luminol with H2O2 generates chemiluminescence captured with a CCD camera. DSG3 is membrane-bound protein in HNSCC cells of invaded lymph nodes, vascular endothelial growth factor-A (VEGF-A), vascular endothelial growth factor-C (VEGF-C) were positive controls overexpressed into the HNSCC culture medium. Beta-tubulin (β-Tub) was used as a loading control to estimate the number of cells in analyzed samples. Limits of detection (LOD) were 0.10 fg/mL for DSG3, and 0.20 fg/mL for VEGF-A, VEGF-C and β-Tub. Three orders of magnitude semilogarithmic dynamic ranges were achieved. VEGF-A showed high in-cell expression, but VEGF-C had low levels inside cells. The very low LODs enabled quantifying these proteins released from single cells. Strong correlation between results from on-chip cell lysis, conventional off-line lysis and ELISA confirmed accuracy.

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.

Photoacoustic Molecular Imaging for the Identification of Lymph Node Metastasis in Head and Neck Cancer Using an Anti-EGFR Antibody-Dye Conjugate

The presence of lymph node (LN) metastases is an essential prognostic indicator in patients with head and neck squamous cell carcinoma (HNSCC). This study assessed photoacoustic molecular imaging (PAMI) of the antiepidermal growth factor receptor antibody (panitumumab) conjugated to a near-infrared fluorescent dye, IRDye800CW (panitumumab-IRDye800CW; pan800), for the identification of occult metastatic LNs in patients with HNSCC (n = 7). Methods: After in vitro photoacoustic imaging characterization of pan800, PAMI was performed on excised neck specimens from patients infused with pan800 before surgery. Freshly obtained neck specimens were imaged with 3-dimensional, multiwavelength spectroscopic PAMI (wavelengths of 680, 686, 740, 800, 860, 924, and 958 nm). Harvested LNs were then imaged with a closed-field near-infrared fluorescence imager and histologically examined by the pathologist to determine their metastatic status. Results: In total, 53 LNs with a maximum diameter of 10 mm were analyzed with photoacoustic and fluorescence imaging, of which 4 were determined to be metastatic on the final histopathologic report. Photoacoustic signals in the LNs corresponding to accumulated pan800 were spectrally unmixed using a linear least-square-error classification algorithm. The average thresholded photoacoustic signal intensity corresponding to pan800 was 5-fold higher for metastatic LNs than for benign LNs (2.50 ± 1.09 arbitrary units [a.u.] vs. 0.53 ± 0.32 a.u., P < 0.001). Fluorescence imaging showed that metastatic LNs had a 2-fold increase in fluorescence signal compared with benign LNs ex vivo (P < 0.01, 0.068 ± 0.027 a.u. vs. 0.035 ± 0.018 a.u.). Moreover, the ratio of the average of the highest 10% of the photoacoustic signal intensity over the total average, representative of the degree of heterogeneity in the pan800 signal in LNs, showed a significant difference between metastatic LNs and benign LNs (11.6 ± 13.4 vs. 1.8 ± 0.7, P < 0.01) and an area under the receiver-operating-characteristic curve of 0.96 (95% CI, 0.91-1.00). Conclusion: The data indicate that PAMI of IRDye800-labeled tumor-specific antibody may have the potential to identify occult LN metastasis perioperatively in HNSCC patients.

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.

Update on radioguided surgery: from international consensus on sentinel node in head and neck cancer to the advances on gynaecological tumors and localization of non-palpable lesions

The aim of this review is to provide an updated perspective on different fields of radioguided surgery. With reference to the sentinel lymph node biopsy in oral squamous cell carcinoma, we present the results of the interactive debate held at the recent Congress of our specialty about the more relevant aspects of the London Consensus. Drainage peculiarities and indications according to the current guidelines on gynaecological tumours, endometrial and cervical cancer, are detailed and new scenarios for nuclear medicine physicians are presented; robotic surgery and hybrid tracers, for instance. Moreover, the notable growth in radioguided surgery indications for non-palpable lesions, widely used in mammary pathology, make it advisable to update two procedures which have shown satisfying results, such as the solitary pulmonary nodule and the osteoid osteoma.

The EANM practical guidelines for sentinel lymph node localisation in oral cavity squamous cell carcinoma

Purpose

Sentinel lymph node biopsy is an essential staging tool in patients with clinically localized oral cavity squamous cell carcinoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery, and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with early N0 oral cavity squamous cell carcinoma.

Methods

These practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) and the International Atomic Energy Agency (IAEA) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, and national nuclear medicine societies. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI).

These guidelines, together with another two focused on Surgery and Pathology (and published in specialised journals), are part of the synergistic efforts developed in preparation for the “2018 Sentinel Node Biopsy in Head and Neck Consensus Conference”.

Conclusion

The present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of early N0 oral cavity squamous cell carcinoma patients.

Data Set for the Reporting of Nodal Excisions and Neck Dissection Specimens for Head and Neck Tumors: Explanations and Recommendations of the Guidelines From the International Collaboration on Cancer Reporting

Standardized, synoptic pathologic reporting for tumors greatly improves communication among clinicians, patients, and researchers, supporting prognostication and comparison about patient outcomes across institutions and countries. The International Collaboration on Cancer Reporting is a nonprofit organization whose mission is to develop evidence-based, universally available surgical pathology reporting data sets. Within the head and neck region, lymph node excisions and neck dissections are frequently performed as part of the management of head and neck cancers arising from the mucosal sites (sinonasal tract, nasopharynx, oropharynx, hypopharynx, oral cavity, and larynx) along with bone tumors, skin cancers, melanomas, and other tumor categories. The type of specimen, exact location (lymph node level), laterality, and orientation (by suture or diagram) are essential to accurate classification. There are significant staging differences for each anatomic site within the head and neck when lymph node sampling is considered, most importantly related to human papillomavirus–associated oropharyngeal carcinomas and mucosal melanomas. Number, size, and site of affected lymph nodes, including guidelines on determining the size of tumor deposits and the presence of extranodal extension and soft tissue metastasis, are presented in the context of prognostication. This review elaborates on each of the elements included in the data set for Nodal Excisions and Neck Dissection Specimens for Head & Neck Tumours.

Design and Synthesis of 99mTcN-Labeled Dextran-Mannose Derivatives for Sentinel Lymph Node Detection

Background: New approaches based on the receptor-targeted molecular interaction have been recently developed with the aim to investigate specific probes for sentinel lymph nodes. In particular, the mannose receptors expressed by lymph node macrophages became an attractive target and different multifunctional mannose derivate ligands for the labeling with ^99mTc have been developed. In this study, we report the synthesis of a specific class of dextran-based, macromolecular, multifunctional ligands specially designed for labeling with the highly stable [^99mTc≡N]²⁺ core. Methods: The ligands have been obtained by appending to a macromolecular dextran scaffold pendant arms bearing a chelating moiety for the metallic group and a mannosyl residue for allowing the interaction of the resulting macromolecular ^99mTc conjugate with specific receptors on the external membrane of macrophages. Two different chelating systems have been selected, S-methyl dithiocarbazate [H₂N‒NH‒C(=S)SCH₃=HDTCZ] and a sequence of two cysteine residues, that in combination with a monophosphine coligand, are able to bind the [^99mTc≡N]²⁺ core. Conclusions: High-specific-activity labeling has been obtained by simple mixing and heating of the [^99mTc≡N]²⁺ group with the new mannose-dextran derivatives.

Effectiveness of Preoperative Lymphoscintigraphy for the Detection of Cervical Lymph Node Metastasis in Patients with Oral Squamous Cell Carcinoma

Background:

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumor. OSCC is the malignancy of squamous epithelium of oral cavity, which is the sixth most common malignancy reported worldwide and one with highest mortality rate among all malignancies.

Aims:

The aims of this study is to assess the diagnostic performance of lymphoscintigraphy (LSG) for the detection of cervical lymph node metastasis in patients with OSCC.

Materials and Methods:

This was a prospective study done in Oral and Maxillofacial Surgery Department and National Institute of Nuclear Medicine and Allied Science, Bangabandhu Sheikh Mujib Medical University during July 2015–June 2016. Thirty-six patients with OSCC were included in this study. Radioisotope technique was used in the detection of cervical metastases in patients with histologically proven OSCC. Patients were assessed by LSG after diagnosis of OSCC, and then, it was compared with postoperative histopathology report.

Results:

Lymphoscintigraphically out of 36 patients, 23 had lymphatic channel obstruction where histologically 20 patients had lymph node metastasis. There were 20 true positive cases, 13 true negative cases, and 3 false positive cases but no false negative case was found. The test of validity result reveals that sensitivity 100.0%, specificity 81.25%, accuracy 96.66%, positive predictive value 86.96%, and negative predictive value 100.0%.

Conclusion:

LSG for the detection of cervical lymph node metastasis has an important role for the management of OSCC. It is also cost-effective and decreases the morbidity.

Sentinel Lymph Node Biopsy: A new approach in the management of head and neck cancers

Cervical lymph node metastasis affects the prognosis and overall survival rate of and therapeutic planning for patients with head and neck squamous cell carcinomas (HNSCCs). However, advanced diagnostic modalities still lack accuracy in detecting occult neck metastasis. A sentinel lymph node biopsy is a minimally invasive auxiliary method for assessing the presence of occult metastatic disease in a patient with a clinically negative neck. This technique increases the specificity of neck dissection and thus reduces morbidity among oral cancer patients. The removal of sentinel nodes and dissection of the levels between the primary tumour and the sentinel node or the irradiation of target nodal basins is favoured as a selective treatment approach; this technique has the potential to become the new standard of care for patients with HNSCCs. This article presents an update on clinical applications and novel developments in this field.

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.

Technique for reliable sentinel node biopsy in squamous cell carcinomas of the floor of mouth

BACKGROUND

Applicability of sentinel node biopsy (SNB) for tumors of the floor of mouth (FOM) is controversial.

METHODS

Prospective evaluation of the accuracy of gamma-probe-guided superselective neck dissection of the preglandular triangle of level I for SNB in FOM squamous cell carcinoma (SCC) after preoperative lymphoscintigraphy and single photon emission CT (SPECT)/CT.

RESULTS

In total, 22 sentinel lymph nodes were harvested in level I. Eight of 22 (36%) were seen on lymphoscintigraphy and 11 (50%) on SPECT/CT. Eleven sentinel lymph nodes (50%) were only detected intraoperatively. In unilateral tumors, 20% were contralateral, and, in midline tumors, 93% showed bilateral level I sentinel lymph nodes. The false-negative rate was 8.3%, the negative predictive value was 96.4%, and the false-omission rate was 3.6%. The ultimate neck control rate, including salvage treatment, was 100%.

CONCLUSION

SNB in FOM can be reliably performed using the presented surgical technique. Level I exploration, bilaterally in midline tumors, is mandatory irrespective of the visualization of sentinel lymph nodes in other levels. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1367-1372, 2016.

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.

The history of sentinel node biopsy in head and neck cancer: From visualization of lymphatic vessels to sentinel nodes

The aim of this report is to describe the history of sentinel node biopsy in head and neck cancer. Sentinel node biopsy is a minimally invasive technique to select patients for treatment of metastatic lymph nodes in the neck. Although this procedure has only recently been accepted for early oral cancer, the first studies on visualization of the cervical lymphatic vessels were reported in the 1960s. In the 1980s mapping of lymphatic drainage from specific head and neck sites was introduced. Sentinel node biopsy was further developed in the 1990s and after validation in this century the procedure is routinely performed in early oral cancer in several head and neck centers. New techniques may improve the accuracy of sentinel node biopsy further, particularly in difficult subsites like the floor of mouth.

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.

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.

Freehand SPECT-guided sentinel lymph node biopsy in early oral squamous cell carcinoma

BACKGROUND

In oral squamous cell carcinoma (OSCC), cervical lymph node status is the most important prognostic factor. Compared to elective neck dissection, reduced morbidity and better quality of life was demonstrated for sentinel lymph node biopsy, which is controversial because of the reduced detection rate of sentinel lymph nodes in close proximity to the injection site (also known as the shine-through phenomenon).

METHODS

We report the case of a 44-year-old woman with a biopsy-proven early OSCC of the anterior floor of the mouth, who received SLNB guided with freehand single-photon emission CT (fhSPECT), a system for the 3D visualization of radioactivity in the body.

RESULTS

One level III sentinel lymph node and 1 level I sentinel lymph node, in close proximity to the injection site, were detected and dissected. The level I sentinel lymph node contained a metastasis.

CONCLUSION

Using fhSPECT, the issue outlined was overcome, and the precise histopathological lymph node status (pN1; 1 of 49) was determined.

SPECT/CT and tumour imaging

Scintigraphic techniques are sensitive imaging modalities in the diagnosis and follow-up of cancer patients providing the functional and metabolic activity characteristics of the tumour. Hybrid SPECT/CT improves the diagnostic accuracy of these well-established imaging techniques by precise anatomical localization and characterization of morphological findings, differentiation between foci of physiological and pathological tracer uptake, resulting in a significant impact on patient management and more definitive interpretations. The use of SPECT/CT has been studied in a variety of applications in tumour imaging which are reviewed in this article. By combining functional and anatomical information in a single imaging session, SPECT/CT has become a one-stop cancer imaging modality.

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

OBJECTIVE

Various lymphoscintigraphic imaging protocols exist for sentinel node (SN) identification in early-stage oral cancer. This study aimed to evaluate the clinical value of performing additional late lymphoscintigraphic imaging.

METHODS

We retrospectively analysed early (directly following injection of 99mTc-Nanocoll) and late (2-4 h after injection) imaging results of 60 early-stage (T1-T2, cN0) oral cancer patients scheduled for SN procedure. Lymphoscintigraphic results of late imaging were categorized into: (a) no visualization of additional hotspots considered to be SNs; (b) additional hotspots visualized that are considered to be SNs and (c) hotspots visualized only during late imaging. Histopathological results of the harvested SNs were related to the corresponding hotspot.

RESULTS

In all patients (n=60) lymphoscintigraphy was able to visualize a hotspot that was identified as an SN. In 51/60 (85%) patients, early imaging was able to visualize at least one hotspot, whereas in 9/60 (15%) patients, mostly with oral cavity tumours other than mobile tongue and floor-of-mouth tumours, only late imaging was able to visualize hotspots. In 14/51 (27%) patients, late imaging resulted in additionally visualized hotspots marked as SNs, resulting in a more extensive surgical procedure. These additionally removed SNs appeared to be of no clinical relevance, as all SNs identified during early imaging correctly predicted whether the neck was positive or negative for cancer.

CONCLUSION

Results of this study indicate that additional late lymphoscintigraphic imaging should be performed only in selected cases.

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.

Axillary sentinel node identification in breast cancer patients: degree of radioactivity present at biopsy is critical

BACKGROUND

The radioactivity present in the patient (Act(rem) ) at sentinel node (SN) biopsy will depend on injected activity amount as well as on the time interval from tracer injection to biopsy, which both show great variations in the literature. The purpose of this study was to analyse the influence of varying Act(rem) levels on the outcome of axillary SN biopsy in patients with breast cancer (BC).

MATERIAL AND METHODS

Eight hundred and fifty-eight patients with BC were consecutively referred to SN biopsy, 21% for a same-day and 79% of the patients for a 2-day procedure. Four hundred and nineteen patients underwent scintigraphy and 439 did not. For same-day procedures, 50 MBq (99m) Tc-nanocolloid (Nanocoll(®) ) was injected, and for 2-day procedures 110 MBq. For the analysis of SN biopsy outcome, the patients were divided into three Act(rem) groups: <10 (56% of the patients), 10-20 (23%), and >20 MBq (21%). During surgery, SNs were located using a hand-held gamma probe supported by image information when available and blue dye injection. Pathology included haematoxylin-eosin staining followed by immunohistochemistry.

RESULTS

The number of SNs removed (mean value 1·87 versus 2·14, P = 0·0003) and the probability of finding a malignant SN (P = 0·034) were lower in the <10 MBq group of patients compared with higher Act(rem) >20 MBq. Of the 25 patients with SN non-detection, 20 patients had an Act(rem) <10 MBq. Imaging had no significant influence on the number of patients with a malignant SN (P = 0·48).

CONCLUSION

Act(rem) above 10 MBq for nanocolloid tracer appears important for appropriate identification of SNs in patients with BC.

Current trends and future perspectives in the surgical management of oral cancer

Surgery remains the frontline treatment for oral cancer. Factors affecting the surgical management are related to the staging of the primary disease and the presence of regional or distant metastasis. Histopathological parameters such as tumour grade, depth and pattern of invasion are of paramount importance for the extent of the surgical treatment. Surgery of the neck is evolving to more selective treatments and the concept of sentinel lymph node biopsy is gradually been established in the management of the neck for early oral cancer. Reconstruction of the defect is mainly performed with free flaps. Further refinement in the flap selection and harvesting techniques will lead to free-style flap reconstruction, minimising the morbidity of the donor site and increasing the versatility of reconstruction at the recipient site.